@@ScottDLR Some kinds of insulation that are fire safe will often set on fire then quickly put themselves out. I've seen this with home wiring and plugs. They add something in the plastic. It will burn for a second or so before going out, but this could make something nearby catch fire. No idea if the same stuff is used in aviation though.
An overloaded wire acts like a resistor, more similar to a heating coil found in a space heater or toaster. Once the wire gets hot enough, the insulation may melt. Resistive (Joule) heating at its finest.
A company I worked for hired contractors to install safety related equipment on public transport vehicles, but we had to check and confirm their work was done correctly afterwards. Only later did we find out our company estimated a 50% failure rate at install...so we did almost 50% of the modifications despite paying for contractors.
I cringe every time I see an incident caused by poor or incorrect maintenance. As an electrical & electronics engineer with almost 40 years experience, this one really made my skin crawl - this was the equivalent of replacing a blown fuse with a rolled up piece of aluminium foil - there's a reason you should never do that sort of thing - bypassing any kind of overload protection is never going to end well - you may get away with it for quite a long time but one day, sooner or later, it's gonna bite your ass big time :(
To be fair, this wasn't so much incorrect maintenance, as it was an incorrect implementation of a modification to the plane. Incorrect maintenance would have been to change the wires at the specified interval, but connecting them incorrectly at that point. This one is significantly worse, as all modifications should be checked thoroughly by multiple instances, before being declared airworthy.
Reminds me of Drachinifel's video about a sailor tying down a circuit breaker in a WW2 battleship at Guadalcanal. Led to cascading blackouts throughout various parts of the ship. Which was therefore going around in circles, blind and unable to communicate, while the Japanese forces kept firing their guns....
All I hear is " oh everybody look at me, I'm an electrician. I work with electricity. I know how to work with electricity way better than you do." Hahaha
@@LoneWolf-gm5qm All I hear is "oh everybody look at me, I'm a lone wolf. I can do everything better than everyone else. I don't need no pack. Everyone else is always wrong and I'm always right. Also, I don't understand why nobody likes me." Hahaha
That happens in cars a lot - the current supplied by a battery in a short circuit is enormous - Great video and we can all take away a learning point ! Thanks a million !
A friend of my dad once worked as supervisor in the aircrat industry. He once told us he feld about quitting the job. When we asked why, he stated, that they had a new production management boss. And that guy had come from the car industry and was pushing to implement faster procedures from the car industry. The buddy said, he wouldn`t want to be part of this company anymore, if it starts to take shortcuts in the production process and negetiate safety priorities. Had to think of that convo, when the 737 MAX thing occured. Quality dropping for profit is something, that has no place in the aircraft industry.
This is true, I have worked in body shops over 40 years I is amazing how creative some people are, back in the day of the giant boom box a kid drilled a hole in his fire wall to run strait 12 volt cables the size of your thumb to his power supply in the trunk no grommets or wire protection at all after it shorted burned his car to the ground people also disable fuses or put the biggest one they can find in when they start blowing
This type of shitty workmanship can be found in all types of machinery, from automotive to industrial and apparently aviation as well. Some mechanics just have no business anywhere near sensitive equipment, it's infuriating how most people just don't give a shit about the work they do.
I worked on cars for decades, back in the 90s when almost everything had a timing belt we did the line up check and had another double check. How could that company, just like Dr Evil, assume everything was done according to plan.
Hoo boy, I remember being young and idealistic and running head first into "That's the way it's always been done, now shut up newbie or get fired or aggressively hazed into quitting!" even things in direct conflict with operating and policy manuals.
Nice mid-air collision at the end of the video simulation there between the Learjet and a smaller plane taking off! Buddy systems do exist elsewhere very commonly. GMP and GLP (Good Manufacturing Practice and Good Laboratory Practice) standards are mandatory for big Pharma and medical device manufacturers worldwide...one person does the work, the other shadows and checks it off on the quality assurance paperwork....then next day, they swap over.
I never heard about this incident until now. I'm somewhat stunned that this was caused by an improperly implemented military modification. As a former military avionics tech my training was crystal clear: Always refer to appropriate documentation and procedures! I just can't imagine one tech telling another "Do it like this." I wouldn't have touched a thing without having the correct schematics, wiring diagrams and modification procedures readily available. A tragic lack of oversight and such a senseless tragedy. Thank you for doing this video. Great work as always!
This is the kind of crap that I would expect to see on a DIY car stereo install, and this is a multi-million dollar jet. I’m quite amazed at this piss-poor workmanship.
@@maximme The military complex is the most capitalist as capitalism can be, even in a proclaimed communist country like China or North Korea. Hilarious conclusion you just made
@@maximme How so? Paid by taxes? So is the government, so are public streets! And public streets do not have private contractors do work for them for money …
@@maximme Wait until you find out who bailed out all the big Wall Street banks making reckless bets that blew up in their faces in 2008, the auto industry, and soybean farmers...
This one kind of has shades of Swissair 111 to it. An aftermarket electronic system cobbled into the airplanes power busses in such a way that unintentionally bypassed critical safety systems. And here’s the problem with “better maintenance oversight”. It presumes that the correct procedures for installing the device are communicated to the installation team, and known by at least one supervisor. If they are working from incorrect or insufficient documentation, then the error simply propagates regardless of oversight. And nobody will ever realize it until a plane comes down.
I've been electrician for 30 years and putting a fuse, fusible link or current limiting device at the source is electrical principles 101. It is truly astounding that a single technician with even a rudimentary understanding and elementary training in basic electrical principles could do this, is unbelievable. The fact that another, or multiple people would copy such a basic flaw is mind-blowing indeed.
Runway, definition: place of maximum flying aircraft density, not just close to but actually on the ground, often with very low speed aircraft … and where stricken aircraft try to go to die.
You know what they say about the "first 15 seconds and the last 15 seconds" being the most dangerous parts of the flight. And they can ONLY occur near or on the runway.
Qualified personal for doing repairs is a must. Lazy technician didn't state exactly what to put where. Knowing the other technician ask a question, he should have checked and explained where the connection is to be made and why. I take my time and explain things to ppl that want to learn, it makes them a better technician and person overall.
As someone who does aircraft wiring for a living, I would never do a connection without a schematic from the engineer that gave the specific location to be connected. This kind of scenario is exactly why
40 years as an A&P. The differences between aircraft of the same model can be many. We have to be certain that the wiring diagrams, procedures, or parts list are for that serial number aircraft. And is it pre or post Service Bulletin X. There are dozens of variants. Also I stay far away from Public Use aircraft. Several times I have been asked to work on the local police department helicopters. Never. Flying death traps IMO. Many don’t have an Airworthiness Certificate. Inspections aren’t required. Seems hard to believe, I know. Research it. Fix things when they break, nothing more. Often these aircraft are military surplus. Never had a FAA Airworthiness Certificate.
Holy sheet, that's seriously eff'd up! No way could anyone explain / defend this situation to my personal satisfaction, and I'm certain that many many others with better knowledge of the aircraft industry must feel the same. Tragic.
The buddy system might cause resentment or even lack of confidence for certain individuals but it'd be worth it just to make sure things like this didn't happen. If I've bungled something important it sucks to find out you have done just that but I'd rather know.
If it causes resentment, then that technician shouldn't be allowed to operate IMHO. Nobody is infallible, and frankly anybody arrogant enough to believe that they don't need oversight to catch the occasional mistake is a danger to anyone relying on the quality of their work. There's no room for ego in safety critical work, especially not where other peoples' lives are on the line. To put things more succinctly: to err is human, to assume you won't err is stupid and dangerous.
As an aside, the Learjets were actually developed from a military prototype, the Swiss FFA P-16 ground-attack fighter. There are rumors that the first generations still shared a lot of the flight characteristics of the fighter. I have no idea if any of this shared a role in making Learjets attractive to the military.
Cheaper to buy a plane instead of inventing a plane. Poke around for ATC chatter about a mystery airplane reported by pilots up around fl 40 that was not appearing on radar. It was a 737 testing radar canceling ecm that apparently worked. PS Lear's grubstake was the royalties from inventing the 8 track tape player.
@@billdurham8477 ATC doesn't really have radar like the military anymore. Instead they have a system that sends out a signal that every aircraft in the area has a radio box (transponder) in it that responds to the ping with a reply that gives a bunch of data in it. Simply turning off your transponder will make you invisible to ATC. I test transponders for a living, aircraft need a test every two years to remain airworthy
@@charlottehardy822 😂😂 I love Kelsey, he's just such a likable guy! And did you just use the verb "roast" to describe a video about a fire? Good pun, intended or not. LoL
As far as i know most maintenance procedures under EASA rules have to be done as you suggest. One engineer is responsible for the modification, and then another check engineer has to check the work is done according to spec and sign off on that. Now, i only fly the damn things, therefore i might be mistaken, however that is how it was explained to me why we always get at least 2 maintenance engineers turning up when we have an issue.
Great Video as always man. I really like to hear about these less know incidents, even with the well known ones you still give a more detailed analysis and your reporting is spot on. Could you do a video of Nationwide Flight 723, which departed Cape Town International and shortly after lift-off the right hand engine separated from the aircraft. I know its not common that to request videos but if you can it would mean alot, thank you in advance.
They do have a buddy system, it's called duplicate inspection. While watching the video I was saying even if the supervisor was directing the other guy he should have inspected his work afterwards....sheeesh
Just like an incandescent light bulb... something we've used as an igniter for a pyrotechnic effect in movies. Fortunately, we can call "cut!" and do take two. That's something you can't do in real life. Tragic accident... or would we really call that negligence?
A buddy system for maintenance would have prevented countless crashes over the years. It would have to be mandatory though as it would hit the airlines in the pocket.
Airlines all have duplicate inspection requirements, normally referred to as RII (required inspection item) in the industry. It's very common in other parts of aviation. I maintain a king air and am the only mechanic for it. I get mechanics from the business that shares the hangar to inspect what I do, or even a pilot if no mechanics are around. 30 years in maintenance now, I've worked in every type there is, and inspected plenty of other people's work.
I imagine that checking work in a hard to reach area becomes logistically complicated quickly. Some steps also need to be verified on a very fine resolution to be effective Imagine Step 12 being a crimp followed by Step 13 Heath Shrink Tube, Step 14 Strain relief, Step 15 Cover Plate Mounting, Step 16 closing maintenance access door... all while in an awkward position.
This reminds me of, if memory serves me correctly, Swissair flight 111, that crashed off the coast of Nova Scotia. New wiring for an entertainment system, had been installed in the ceiling. The work was not done correctly and the wires chaffed, causing a spark that ignited the flammable (mylar) insulation. Two stupid mistakes were made which caused this crash, one by the contractor, the other by the aircraft manufacturer who put flammable insulation in an aircraft. I’m a retired power maintenance electrician and stuff like this just makes me cringe.
Very interesting video. Could I ask why a spark is required to cause the fire in the cable? Did NTSB say it was?No source of ignition is needed to start a fire, just fuel oxygen and heat. The insulation can easily ignite from the heat of a very heavy amp overload. No spark required.
@@jamesstuart3346 The airframe is the ground, so yes, it’s part of the circuit. And yes, no spark is required, every material has a temperature where it self-combusts. No spark is needed when the temperature reaches this value
There is something called quality control office and its used in many aspects of business. Its used as an oversight tool in many different stages of manufacturing. You would think ANYTHING with the words military attached to it or aircraft in general would have at its disposal a QCO. A control office which in this case should have existed within the maintenance department. Regardless of the fact that this was obviously a subcontractor, Its a plane!!!. Its a shame when you think of flying you don't spasticly think of safety 🤔??? I mean I'm not afraid of flying but usually the first thing I wanna know is the age of my plane? From there if its really old sometimes I'll actually take a different flight because of that alone. To me the more modifications the more chances for things to go wrong. Its just Sad regardless. Thank you for a great video!
Hello, While a buddy system will probably help alleviate some issues, it will not resolve the root-cause problems. Here are my thoughts about the actual root causes of the problems shown in the video: NOT using schematics and drawings to communicate to the technician the needed job at hand. The actual purpose of drawing is precisely to remove guess-work from wiring and to allow standard methods to be implemented, in each and every job A sad lack of training, no one should be doing a job without understanding the safety implications that might result from mistakes. Unfortunately, the upper management often carries preconceived ideas about the challenges of jobs. I have worked for decades in the USA and found that too often the upper management makes a critical decision based on unsubstantiated statements and grossly underestimates the challenges of tasks since they usually have a vested interest in reducing the cost of making things The requirement to keep investors and stakeholders happy, sometimes interfere with the quality of the job, and almost every time the former takes precedence over the latter. Thanks for giving me the opportunity to speak my mind Cheers
It would seem that whatever connector is used in the wiring at that point should have had a slight variation to not allow such a bypass in the first place... or if it was a rare necessity to do such a bypass, to have some warning constantly on to the cockpit computer about such a bypass so that it would be monitored and repaired and not forgotten. It might have been a limitation of the early 90s computer tech to be in that gap between analog and digital components. The design may have been seriously outdated.
You assume an actual connector plugged in somewhere. I assume wires that simple get stripped and fitted with "adequate and industry standard solution" to connect point a and b. It is the nature of after marketed electronics that they need to be integrated somehow into many different systems/planes that has not been prepared for it.
First thing my Auto shop teacher did on day 1 of school year was... -put on a shop coat and safety glasses -pick up an 18 in piece of 12-gage wire using insulated-handled pliers at each end -hold each wire end to the opposing terminals of a 12V car battery POOF! Hardly what you would call a fire! "Just" INSTANTANEOUS COMBUSTION! All the insulation was immediately vaporized. This is what happens if you wear a watch or jewellery while working under the hood or the dash, he said. Wow! Most impactful lesson I ever learned.
Worked as an electrician who installed a jumper wire after generator was up to speed so any secondary failure would trip the reactor - we used the buddy system - he failed once & I fixed the error - years later he failed again & which lead to no safety failure protection during a fault - You need a supervisor or other well trained personal for major safety related work -
'This is the way we've always done it' is the source of many, many problems. When I was an industrial engineer a wise manager told me to be aware of that always. Start from scratch.
It's a miracle that none of the other 14 planes, that were modified, didn't crash and burn. Total incompetence by everyone involved, and it happens way too often.
Yes to buddy system. People's lives are at stake. As a Special Ed teacher,I was always asking for help from my peers. Their ideas and/or agreements meant that I would give my students the best techniques to "make them soar!"✈️ Thank you for today's post snd all your posts. Sincerely, Marilynn
I flew on that plane about a year before it went down. Nice to know why it went down. When you board it, It had a narrow isle with a backwards jump seat. An electronics seat and in front pilot and copilot. Everything else was radar jamming eq.
When a mechanic’s work can bring down a passenger plane resulting in hundreds of deaths, there definitely should be a second and third inspection afterwards🙁 The same with the co-pilot’s walk around checking the outside of the plane, they should have a checklist in hand that is checked and ticked off - how many accidents have been caused because a piece of tape was left on , covering the pitot tube🙁
I'm an A&P (airplane mechanic) and I noticed a lot of people talking about a buddy system. If it eases anyone's mind, things that are considered critical to flight safety, almost always require a designated inspector to verify the work was done correctly. I imagine that in this instance, complacency played a big role.
For perspective: the added unit was running a load of up to 300 amps. An average house these days runs a breaker panel of 200 amps, sufficient to run an electric range and oven full blast, the lights, refrigerator, dryer and other things simultaneously...
Looks like you were using a Cessna cockpit for the interior shots. I only know that because I have the CJ4 sim and mostly fly the Learjet in Flight sim. I like your channel a lot. Your videos are really well done.
The way we perform maintenance on aircraft in the army is if you’re removing anything, from a plug to an entire component, you have to have a technical inspector (TI) come and verify your work before you can call it complete
Seems like copying from another aircraft or repeating whatever was done before should be unacceptable. Referencing the manual should be mandatory. British Airways 5390, for example, happened because the maintenance personnel used bolts that were the same as what was in there already instead of checking the manual and it turns out that the wrong bolts were used by whoever did it the first time. Copying a mistake with another mistake.
You should NEVER copy what another tech has done - ALWAYS follow the procedure as laid down in the book, unless a service bulletin is issued to the contrary (in which case you should follow the new book) Sounds blatantly obvious really, but you'd be surprised how many times I've seen people fail in this basic methodology. Fortunately they weren't working in aviation
This copy-cat repetition is rather like the essence of blindly following “tradition” - if the original was based on true “knowing” then all should be well, given that no other changes were made that might affect the overall result. But if the original was wrong (even partially), then disaster will ultimately visit. So the same goes for religious and even secular traditions - if the original was wrong, or is later misinterpreted or corrupted well, too bad! And that is why ever present, “fresh”awareness is essential, or death ☠️!! Like the aviator/novelist Ernest Gahn said, “Fate is the Hunter”!!
@@countzero1136 100% agreed. I live about a half mile from an aviation maintenance training school. Sometimes I see the students in the coffee shop near my house. I don't want to be a Mr. Know-It-All and rant about thoroughness and the responsibilities inherent in the career they're about to embark on. But it sure is tempting, especially after seeing so many of these air crash investigation videos. Just one little 'whoops' and people die.
@@Will-fn7bz If everybody just did their jobs properly and followed procedures correctly, there would be no need for you or I to have to take them to task over it...
We do have a buddy system.. the tech and the inspector who signs the paperwork off. In 30 years of maintenance on aircraft..the inspector sometimes doesn't see errors..this happens alot. The copy method isn't approved by the FAA, so the management of the contractor is mostly at fault
What we do at work, on networks of computers, is to write the procedure and test it in a lab with the same equipment as production, send the procedure to a second team that reviews it and tests it on other lab equipment, then review the procedure on a call. When we implement things on the production systems, we're all on the call making sure the person executing the procedure is doing it correctly, and we handle any deviations in the production systems by backing out the procedure, fixing the discrepancy, then re-trying it. So sort of a buddy system, but in a long, drawn-out way.
Hi there, An interesting video for me since I've been involved in Learjet airworthiness and modification for many years. There IS a 'Buddy' system for maintenance technicians. It's tje Independent Inspection (also known as Duplicate Inspection). This is needed for all flight safety sensitive maintenance tasks. Also, a technician that is licensed and allowed to sign must know what to do,and not just shown by someone else. That would be gross negligence. I know that FAA rules are significantly more lax than EASA rules, but there is no justification for this, if the story is complete. Incidentally, technicians are to write down the exact references to the wiring diagrams used and must work with the documentation at hand. Thank you for the video. I will certainly look up the NTSB report and try to understand what happened with more details. Cheers Mark
Weeeeell, not to alarm anyone, but I saw this many times in the Air Force. In fact, it was done frequently enough that we had a name for it. We affectionately referred to it as a "Chinese blueprint." I even saw it at Boeing. They don't want to break a person loose to train someone. The person who could instruct was already miles away doing a new job. So the new person, with their trusty camera or phone takes a picture of a completed install and that's the "engineering drawing."
I fix cars. It is very common ‘can you have a look at this, it looks wrong…’ we ask each other. We catch each other’s mistakes. We both have to be happy with ‘it.’ Fist bump. Well spotted.
@@MiniAirCrashInvestigation Um, we're watching your channel, of course we're going to see that! A pilot direct vision issue combined with local ATC control issue incident comes to mind watching that blip, I'd recommend covering the 8 February 2000 Zion, IL mid air collision between N5ZA and N99063.
Honestly, I have been under the false impression that civilian aircraft modifications were peer-reviewed by competent, qualified personnel before recertification. Apparently not. **This channel should be awarded “most improved” channel on UA-cam. When I subbed, there were just a couple thousand others and it was a bit unpolished especially on the video feeds. Great work!**
11:20 I'm a 7-level for egress on USAF F-35s, and that's exactly what we do for it. 5-levels will perform the work, and Red-X 7-levels will inspect the work - thereby taking responsibility for the maintenance performed.
You short out a battery, its internal resistance drops which, in turn, allows more current to flow which then drops the resistance again and so on until the battery eventually explodes.
The quality and skill of some of the people that end up working on airplanes can be down right scary. I used to work with a guy that worked for American Airlines, but he was working part time as a mechanic at the local Suzuki dealership. I thought the quality of his work was bad on ATVs and motorcycles. But the stories he'd tell about the work he did for AA was cause for alarm. He talked about how they'd cut corners on repairs, intentionally close something up before it could be inspected, substitute wrong parts, etc. I hope he was exaggerating, but I fear he wasn't.
For some weird reason, this reminded me of an incident where Lockheed-Martin dumped an under-construction satellite onto the lab floor, doing millions of dollars in damage.
NOAA-19 "On 6 September 2003 at 15:28 UTC, the satellite was badly damaged while being worked on at the Lockheed Martin Space Systems factory in Sunnyvale, California. The spacecraft fell to the floor as it reached 13° of tilt while being rotated. The satellite fell as a team was turning it from a vertical to a horizontal position. A NASA inquiry into the mishap determined that it was caused by a lack of procedural discipline throughout the facility. While the turn-over cart used during the procedure was in storage, a technician removed twenty-four bolts securing an adapter plate to it without documenting the action. The team subsequently using the cart to turn the satellite failed to check the bolts, as specified in the procedure, before attempting to move the satellite. Repairs to the satellite cost US$135 million. Lockheed Martin agreed to forfeit all profit from the project to help pay for repair costs; they later took a US$30 million charge relating to the incident. The remainder of the repair costs were paid by the United States government."
No spark. Without a fuse or breaker, the wire just got hot, like the wires inside a toaster. It became it's own fuse. Eventually, probably quite quickly, it just overloaded to a couple thousand degrees and set anything near it on fire. This is a common issue with people that wire up aftermarket stereos in their cars. Always have a fuse or breaker in line somewhere to prevent shorts.
Any major modification to an aircraft (something that affects the function of it as an aircraft) MUST be signed off by an Inspection Authority licensed A&P mechanic.
I think the civilian FAA mechanics follow a two-person concept. I KNOW the Air Force does. I spent 11 years fixing airplanes in the USAF. I’ve been the technician, the inspecting technician, and a QA inspector.
...yea little wrong about needing a spark. ive seen a transformer rectifier ground wire catch fire all because one phase was missing due to a loose connection. Too much power down a wire can cause it to heat up enough to case the insulation to catch fire.
What you call a "buddy system" is already in place and has been for decades. In real life it's call QA or QC, as in Quality Control or Quality Assurance. Every airline or repair station I ever worked for has it, it's an FAA requirement. Besides that, no work can be done on any aircraft without using some type of approved data, such as maintenance manual, engineering drawing, manufacturer's specs, etc. How that company got away without all that is beyond me.
I think it's far more likely that the wire got hot enough to ignite the insulation at short circuit current, I don't know what voltage systems are on a plane, but judging from the high amps, I think it's like 24-48v max, where a spark jumping a gap over air would be really unlikely. But this is just my assumption, I'm no aircraft mechanic.
A SwissAir MD80 crashed once because of bad wiring of a new entertainment system for first class that intermingled with critical avionics in the cockpit and had no off switch. The jet dove into the ocean at 250 knots after cockpit temperatures hit 600 degrees F.
Standard practice in a factory, you NEVER inspect your own work. It would never have crossed my mind that aircraft maintenance was less stringent than sewn products.
I wonder how a buddy system would help. Some work has to be done on in hard to reach area. The job is not done, until the covers are installed and secured. See where this is going? Person A needs to do the actual job, Person B needs to sign it off, Person A needs to install the cover, Person B needs to sign it off... and then people start complaining about leaving half finished work in the hangar, causing missing work steps and misplaced mounting materials. What I could imagine is photo documentation.
Actually there is something like that which requires 2 licensed technicians to perform the work to be done and under certain circumstances the second person is just there not to be involved in performing the work but only in checking the work is done properly by doing the test and inspecting the work.
An AIrman would have to sign off on the work (FAA form 8130-3). Unfortunately, it's fairly common for these Airman to sign-off without actually looking at the work - which isn't required.. That's probably the part that should change.
Actually you don't need a spark, overloaded wires burn houses down everyday just from being too hot, that's why you have to have larger gauge wiring for more high power situations. A short circuit is an easy way to heat up wire, just check out electric heaters. They can set things on fire too, no spark necessary.
I'm surprised there is no "buddy system" as you call it. At our company there must always be an inspection from another person after the product has been mounted and tested. And we are not even in a safety critical field, it's just for quality control
You don't need a spark. A severely overloaded wire will melt off its insulation and eventually burst into flames.
It'll burn its own insulation
@@jamesturner2126 Yes, in most cases. Aviation and marine insulation are not supposed to be able to burn or sustain a flame.
@@ScottDLR Some kinds of insulation that are fire safe will often set on fire then quickly put themselves out. I've seen this with home wiring and plugs. They add something in the plastic. It will burn for a second or so before going out, but this could make something nearby catch fire. No idea if the same stuff is used in aviation though.
An overloaded wire acts like a resistor, more similar to a heating coil found in a space heater or toaster. Once the wire gets hot enough, the insulation may melt. Resistive (Joule) heating at its finest.
FYI: you can actually WELD with a short circuited battery.
Have a device that does this so I can weld 18650s which is actually powered by 18650s, no solder needed! Really cool.
@@bmc9504 and if you use a spot welder wrong (like I did) you can short a battery with a weld!
Sometimes, you can even do it intentionally.
The MacGyver method, and yes it works.
@@Bean-Time I'll bet that was exciting.
A company I worked for hired contractors to install safety related equipment on public transport vehicles, but we had to check and confirm their work was done correctly afterwards. Only later did we find out our company estimated a 50% failure rate at install...so we did almost 50% of the modifications despite paying for contractors.
I cringe every time I see an incident caused by poor or incorrect maintenance. As an electrical & electronics engineer with almost 40 years experience, this one really made my skin crawl - this was the equivalent of replacing a blown fuse with a rolled up piece of aluminium foil - there's a reason you should never do that sort of thing - bypassing any kind of overload protection is never going to end well - you may get away with it for quite a long time but one day, sooner or later, it's gonna bite your ass big time :(
To be fair, this wasn't so much incorrect maintenance, as it was an incorrect implementation of a modification to the plane. Incorrect maintenance would have been to change the wires at the specified interval, but connecting them incorrectly at that point. This one is significantly worse, as all modifications should be checked thoroughly by multiple instances, before being declared airworthy.
Reminds me of Drachinifel's video about a sailor tying down a circuit breaker in a WW2 battleship at Guadalcanal.
Led to cascading blackouts throughout various parts of the ship.
Which was therefore going around in circles, blind and unable to communicate, while the Japanese forces kept firing their guns....
All I hear is " oh everybody look at me, I'm an electrician. I work with electricity. I know how to work with electricity way better than you do." Hahaha
@@LoneWolf-gm5qm
All I hear is "oh everybody look at me, I'm a lone wolf. I can do everything better than everyone else. I don't need no pack. Everyone else is always wrong and I'm always right. Also, I don't understand why nobody likes me." Hahaha
@@MrNicoJac Touché!
That happens in cars a lot - the current supplied by a battery in a short circuit is enormous - Great video and we can all take away a learning point ! Thanks a million !
A friend of my dad once worked as supervisor in the aircrat industry. He once told us he feld about quitting the job. When we asked why, he stated, that they had a new production management boss. And that guy had come from the car industry and was pushing to implement faster procedures from the car industry. The buddy said, he wouldn`t want to be part of this company anymore, if it starts to take shortcuts in the production process and negetiate safety priorities. Had to think of that convo, when the 737 MAX thing occured. Quality dropping for profit is something, that has no place in the aircraft industry.
This is true, I have worked in body shops over 40 years I is amazing how creative some people are, back in the day of the giant boom box a kid drilled a hole in his fire wall to run strait 12 volt cables the size of your thumb to his power supply in the trunk no grommets or wire protection at all after it shorted burned his car to the ground people also disable fuses or put the biggest one they can find in when they start blowing
This type of shitty workmanship can be found in all types of machinery, from automotive to industrial and apparently aviation as well.
Some mechanics just have no business anywhere near sensitive equipment, it's infuriating how most people just don't give a shit about the work they do.
This is why in a car accident, the fire department cuts the battery cables first thing. Fuel pump sometimes, keeps pumping fuel also.
I worked on cars for decades, back in the 90s when almost everything had a timing belt we did the line up check and had another double check. How could that company, just like Dr Evil, assume everything was done according to plan.
Hoo boy, I remember being young and idealistic and running head first into "That's the way it's always been done, now shut up newbie or get fired or aggressively hazed into quitting!" even things in direct conflict with operating and policy manuals.
As they say, just because it has always been done that way doesn't mean it has been done right.
Nice mid-air collision at the end of the video simulation there between the Learjet and a smaller plane taking off! Buddy systems do exist elsewhere very commonly. GMP and GLP (Good Manufacturing Practice and Good Laboratory Practice) standards are mandatory for big Pharma and medical device manufacturers worldwide...one person does the work, the other shadows and checks it off on the quality assurance paperwork....then next day, they swap over.
I never heard about this incident until now. I'm somewhat stunned that this was caused by an improperly implemented military modification. As a former military avionics tech my training was crystal clear: Always refer to appropriate documentation and procedures! I just can't imagine one tech telling another "Do it like this." I wouldn't have touched a thing without having the correct schematics, wiring diagrams and modification procedures readily available. A tragic lack of oversight and such a senseless tragedy. Thank you for doing this video. Great work as always!
This is the kind of crap that I would expect to see on a DIY car stereo install, and this is a multi-million dollar jet. I’m quite amazed at this piss-poor workmanship.
the military complex is a socialist program.
THIS is the cost of socialism.
@@maximme The military complex is the most capitalist as capitalism can be, even in a proclaimed communist country like China or North Korea. Hilarious conclusion you just made
@@maximme what
@@maximme How so? Paid by taxes? So is the government, so are public streets! And public streets do not have private contractors do work for them for money …
@@maximme Wait until you find out who bailed out all the big Wall Street banks making reckless bets that blew up in their faces in 2008, the auto industry, and soybean farmers...
This one kind of has shades of Swissair 111 to it. An aftermarket electronic system cobbled into the airplanes power busses in such a way that unintentionally bypassed critical safety systems. And here’s the problem with “better maintenance oversight”. It presumes that the correct procedures for installing the device are communicated to the installation team, and known by at least one supervisor. If they are working from incorrect or insufficient documentation, then the error simply propagates regardless of oversight. And nobody will ever realize it until a plane comes down.
Reminded me of SWA 111 too. Similar incident.
Amazing no-one on the ground died :O
Yeah it’s absolutely incredible
Great job explaning a complex electrical issue. I always look forward to your videos.
I've been electrician for 30 years and putting a fuse, fusible link or current limiting device at the source is electrical principles 101.
It is truly astounding that a single technician with even a rudimentary understanding and elementary training in basic electrical principles could do this, is unbelievable. The fact that another, or multiple people would copy such a basic flaw is mind-blowing indeed.
I know this was a special case but it amazes me how many crashes take place in sight of the runway. A few even on the runway.
Runway, definition: place of maximum flying aircraft density, not just close to but actually on the ground, often with very low speed aircraft … and where stricken aircraft try to go to die.
You know what they say about the "first 15 seconds and the last 15 seconds" being the most dangerous parts of the flight.
And they can ONLY occur near or on the runway.
Qualified personal for doing repairs is a must. Lazy technician didn't state exactly what to put where. Knowing the other technician ask a question, he should have checked and explained where the connection is to be made and why. I take my time and explain things to ppl that want to learn, it makes them a better technician and person overall.
As someone who does aircraft wiring for a living, I would never do a connection without a schematic from the engineer that gave the specific location to be connected. This kind of scenario is exactly why
40 years as an A&P. The differences between aircraft of the same model can be many.
We have to be certain that the wiring diagrams, procedures, or parts list are for that serial number aircraft. And is it pre or post Service Bulletin X. There are dozens of variants.
Also I stay far away from Public Use aircraft. Several times I have been asked to work on the local police department helicopters. Never. Flying death traps IMO. Many don’t have an Airworthiness Certificate. Inspections aren’t required. Seems hard to believe, I know. Research it. Fix things when they break, nothing more. Often these aircraft are military surplus. Never had a FAA Airworthiness Certificate.
Holy sheet, that's seriously eff'd up! No way could anyone explain / defend this situation to my personal satisfaction, and I'm certain that many many others with better knowledge of the aircraft industry must feel the same. Tragic.
Yup. Like buying an old cop car: never do it! Used, abused, idled to death,
The buddy system might cause resentment or even lack of confidence for certain individuals but it'd be worth it just to make sure things like this didn't happen.
If I've bungled something important it sucks to find out you have done just that but I'd rather know.
If it causes resentment, then that technician shouldn't be allowed to operate IMHO. Nobody is infallible, and frankly anybody arrogant enough to believe that they don't need oversight to catch the occasional mistake is a danger to anyone relying on the quality of their work. There's no room for ego in safety critical work, especially not where other peoples' lives are on the line.
To put things more succinctly: to err is human, to assume you won't err is stupid and dangerous.
As an aside, the Learjets were actually developed from a military prototype, the Swiss FFA P-16 ground-attack fighter. There are rumors that the first generations still shared a lot of the flight characteristics of the fighter. I have no idea if any of this shared a role in making Learjets attractive to the military.
Iraq mounted a anti-ship missile to a similar aircraft. Apparently they are pretty capable aircraft for the military sector.
Correction it was a Dassault not a Lear jet.
Cheaper to buy a plane instead of inventing a plane. Poke around for ATC chatter about a mystery airplane reported by pilots up around fl 40 that was not appearing on radar. It was a 737 testing radar canceling ecm that apparently worked. PS Lear's grubstake was the royalties from inventing the 8 track tape player.
@@billdurham8477 ATC doesn't really have radar like the military anymore. Instead they have a system that sends out a signal that every aircraft in the area has a radio box (transponder) in it that responds to the ping with a reply that gives a bunch of data in it.
Simply turning off your transponder will make you invisible to ATC.
I test transponders for a living, aircraft need a test every two years to remain airworthy
@@rowerwet that thing sending out a signal is called “radar” and the data from the transponder is called “secondary radar”. See MH370.
One thing I like about your channel is I learn about accidents that others haven't covered widely.
Great video, don’t think Kelsey will be able to roast you on it.
Who is Kelsey?
@@XerxesGammon200 @74gear he’s a pilot who does different airplane videos.
@@charlottehardy822 😂😂 I love Kelsey, he's just such a likable guy! And did you just use the verb "roast" to describe a video about a fire?
Good pun, intended or not. LoL
The butterfly effect of a small lapse in judgement.
Laps in comprehension
As far as i know most maintenance procedures under EASA rules have to be done as you suggest. One engineer is responsible for the modification, and then another check engineer has to check the work is done according to spec and sign off on that.
Now, i only fly the damn things, therefore i might be mistaken, however that is how it was explained to me why we always get at least 2 maintenance engineers turning up when we have an issue.
Great Video as always man. I really like to hear about these less know incidents, even with the well known ones you still give a more detailed analysis and your reporting is spot on.
Could you do a video of Nationwide Flight 723, which departed Cape Town International and shortly after lift-off the right hand engine separated from the aircraft. I know its not common that to request videos but if you can it would mean alot, thank you in advance.
Well, now I know to be very careful when I install ECM pods on my light sport.
They do have a buddy system, it's called duplicate inspection. While watching the video I was saying even if the supervisor was directing the other guy he should have inspected his work afterwards....sheeesh
Whenever you see warning labels and overly big drawings with red arrows that point out seemingly obvious things, THIS is exactly why.
You don't need a spark from a wire to ignite, wires can glow red hot...
Just like an incandescent light bulb... something we've used as an igniter for a pyrotechnic effect in movies. Fortunately, we can call "cut!" and do take two. That's something you can't do in real life. Tragic accident... or would we really call that negligence?
A buddy system for maintenance would have prevented countless crashes over the years. It would have to be mandatory though as it would hit the airlines in the pocket.
Airlines all have duplicate inspection requirements, normally referred to as RII (required inspection item) in the industry. It's very common in other parts of aviation. I maintain a king air and am the only mechanic for it. I get mechanics from the business that shares the hangar to inspect what I do, or even a pilot if no mechanics are around. 30 years in maintenance now, I've worked in every type there is, and inspected plenty of other people's work.
I imagine that checking work in a hard to reach area becomes logistically complicated quickly.
Some steps also need to be verified on a very fine resolution to be effective
Imagine Step 12 being a crimp followed by Step 13 Heath Shrink Tube, Step 14 Strain relief, Step 15 Cover Plate Mounting, Step 16 closing maintenance access door... all while in an awkward position.
@@sarowie been there, done that...
For egress, we have mandatory 2-man concept, especially as much of what we do is explosive maintenance.
It’s amazing how consistent your videos are. I feel once a youtuber gets around 200K subscribers, it will then all happen very fast. You’ll be big.
always love a good ol video after school.
I like the way you narrate these interesting stories. Thank you so much!
This reminds me of, if memory serves me correctly, Swissair flight 111, that crashed off the coast of Nova Scotia. New wiring for an entertainment system, had been installed in the ceiling. The work was not done correctly and the wires chaffed, causing a spark that ignited the flammable (mylar) insulation. Two stupid mistakes were made which caused this crash, one by the contractor, the other by the aircraft manufacturer who put flammable insulation in an aircraft. I’m a retired power maintenance electrician and stuff like this just makes me cringe.
Why was there another plane on the runway near the end of the video? :)
Very interesting video. Could I ask why a spark is required to cause the fire in the cable? Did NTSB say it was?No source of ignition is needed to start a fire, just fuel oxygen and heat. The insulation can easily ignite from the heat of a very heavy amp overload.
No spark required.
In addition current would only jump to the airframe if the airframe were part of the electrical circuit. Is it?
@@jamesstuart3346 The airframe is the ground, so yes, it’s part of the circuit. And yes, no spark is required, every material has a temperature where it self-combusts. No spark is needed when the temperature reaches this value
There is something called quality control office and its used in many aspects of business. Its used as an oversight tool in many different stages of manufacturing. You would think ANYTHING with the words military attached to it or aircraft in general would have at its disposal a QCO. A control office which in this case should have existed within the maintenance department. Regardless of the fact that this was obviously a subcontractor, Its a plane!!!. Its a shame when you think of flying you don't spasticly think of safety 🤔??? I mean I'm not afraid of flying but usually the first thing I wanna know is the age of my plane? From there if its really old sometimes I'll actually take a different flight because of that alone. To me the more modifications the more chances for things to go wrong.
Its just Sad regardless. Thank you for a great video!
These videos are a pleasure to watch . I'd rather pay for ur videos than watch for free
You’re too kind :)
@@MiniAirCrashInvestigation thx. could u look into lauda 004 , taca 110
Love your content, you make it easy to follow stories that are often complex in nature, keep up the good work,
tyvm.
Hello,
While a buddy system will probably help alleviate some issues, it will not resolve the root-cause problems.
Here are my thoughts about the actual root causes of the problems shown in the video:
NOT using schematics and drawings to communicate to the technician the needed job at hand. The actual purpose of drawing is precisely to remove guess-work from wiring and to allow standard methods to be implemented, in each and every job
A sad lack of training, no one should be doing a job without understanding the safety implications that might result from mistakes. Unfortunately, the upper management often carries preconceived ideas about the challenges of jobs. I have worked for decades in the USA and found that too often the upper management makes a critical decision based on unsubstantiated statements and grossly underestimates the challenges of tasks since they usually have a vested interest in reducing the cost of making things
The requirement to keep investors and stakeholders happy, sometimes interfere with the quality of the job, and almost every time the former takes precedence over the latter.
Thanks for giving me the opportunity to speak my mind
Cheers
A buddy system? No it's bloody well called a quality assurance program and it's damn well mandatory in all aviation related fields.
As an AME, I always get my work double checked by another person even if it is an Apprentice. It has served me well in all my years .
It would seem that whatever connector is used in the wiring at that point should have had a slight variation to not allow such a bypass in the first place... or if it was a rare necessity to do such a bypass, to have some warning constantly on to the cockpit computer about such a bypass so that it would be monitored and repaired and not forgotten. It might have been a limitation of the early 90s computer tech to be in that gap between analog and digital components. The design may have been seriously outdated.
You assume an actual connector plugged in somewhere.
I assume wires that simple get stripped and fitted with "adequate and industry standard solution" to connect point a and b.
It is the nature of after marketed electronics that they need to be integrated somehow into many different systems/planes that has not been prepared for it.
First thing my Auto shop teacher did on day 1 of school year was...
-put on a shop coat and safety glasses
-pick up an 18 in piece of 12-gage wire using insulated-handled pliers at each end
-hold each wire end to the opposing terminals of a 12V car battery
POOF! Hardly what you would call a fire! "Just" INSTANTANEOUS COMBUSTION!
All the insulation was immediately vaporized.
This is what happens if you wear a watch or jewellery while working under the hood or the dash, he said.
Wow! Most impactful lesson I ever learned.
Worked as an electrician who installed a jumper wire after generator was up to speed so any secondary failure would trip the reactor - we used the buddy system - he failed once & I fixed the error - years later he failed again & which lead to no safety failure protection during a fault - You need a supervisor or other well trained personal for major safety related work -
'This is the way we've always done it' is the source of many, many problems. When I was an industrial engineer a wise manager told me to be aware of that always. Start from scratch.
It's a miracle that none of the other 14 planes, that were modified, didn't crash and burn. Total incompetence by everyone involved, and it happens way too often.
Yes to buddy system.
People's lives are at stake.
As a Special Ed teacher,I was always asking for help from my peers.
Their ideas and/or agreements meant that I would give my students the best techniques to "make them soar!"✈️
Thank you for today's post snd all your posts.
Sincerely, Marilynn
Most large maintenance facilities use 100% buy back which means a technician must have his work inspected by a QC inspector prior to sign off.
The near miss (!) at 11:33 was terrifying.
Yeah, what was that about. Some kind of easter egg?
I think the pilot in the small blue plane still has his head under his shoulder blades from scrunching down.
Crazy, this happened just down the street from where I live now.
On the report, you missed the line before the line you read. It was a buddy system. The mechanics installed it and the IA checked it. 11:00
I flew on that plane about a year before it went down. Nice to know why it went down. When you board it, It had a narrow isle with a backwards jump seat. An electronics seat and in front pilot and copilot. Everything else was radar jamming eq.
I wasn’t expecting that runway incursion at the end...that startled me. Straight outta right field 😶
When a mechanic’s work can bring down a passenger plane resulting in hundreds of deaths, there definitely should be a second and third inspection afterwards🙁
The same with the co-pilot’s walk around checking the outside of the plane, they should have a checklist in hand that is checked and ticked off - how many accidents have been caused because a piece of tape was left on , covering the pitot tube🙁
Hello! Keep up the good work!!😌
Thank you!
oh. lol. go to 74 gear next? lol
I'm an A&P (airplane mechanic) and I noticed a lot of people talking about a buddy system. If it eases anyone's mind, things that are considered critical to flight safety, almost always require a designated inspector to verify the work was done correctly. I imagine that in this instance, complacency played a big role.
It was. The first line of the report (which he did not read aloud) says so. 11:00
For perspective: the added unit was running a load of up to 300 amps. An average house these days runs a breaker panel of 200 amps, sufficient to run an electric range and oven full blast, the lights, refrigerator, dryer and other things simultaneously...
Looks like you were using a Cessna cockpit for the interior shots. I only know that because I have the CJ4 sim and mostly fly the Learjet in Flight sim. I like your channel a lot. Your videos are really well done.
The way we perform maintenance on aircraft in the army is if you’re removing anything, from a plug to an entire component, you have to have a technical inspector (TI) come and verify your work before you can call it complete
Hey buddy it’s Andrew from Sydney changed my user name again . Was good to see you on 74 gear. , now let me listen to this story !
Nice to see you back!
fake accounts to boost up 74 Gear?
Great narration, good facts, and good lesson.
Seems like copying from another aircraft or repeating whatever was done before should be unacceptable. Referencing the manual should be mandatory. British Airways 5390, for example, happened because the maintenance personnel used bolts that were the same as what was in there already instead of checking the manual and it turns out that the wrong bolts were used by whoever did it the first time. Copying a mistake with another mistake.
You should NEVER copy what another tech has done - ALWAYS follow the procedure as laid down in the book, unless a service bulletin is issued to the contrary (in which case you should follow the new book)
Sounds blatantly obvious really, but you'd be surprised how many times I've seen people fail in this basic methodology. Fortunately they weren't working in aviation
This copy-cat repetition is rather like the essence of blindly following “tradition” - if the original was based on true “knowing” then all should be well, given that no other changes were made that might affect the overall result.
But if the original was wrong (even partially), then disaster will ultimately visit.
So the same goes for religious and even secular traditions - if the original was wrong, or is later misinterpreted or corrupted well, too bad!
And that is why ever present, “fresh”awareness is essential, or death ☠️!!
Like the aviator/novelist Ernest Gahn said, “Fate is the Hunter”!!
@@countzero1136 100% agreed. I live about a half mile from an aviation maintenance training school. Sometimes I see the students in the coffee shop near my house. I don't want to be a Mr. Know-It-All and rant about thoroughness and the responsibilities inherent in the career they're about to embark on. But it sure is tempting, especially after seeing so many of these air crash investigation videos. Just one little 'whoops' and people die.
@@Will-fn7bz If everybody just did their jobs properly and followed procedures correctly, there would be no need for you or I to have to take them to task over it...
Why are you videos so quiet? I have to crank volume to max and turn on boost to hear you, other videos are all no boost and volume at 15-25%
You are right, this one was recorded at -15.2 dB.
You can see the exact recording level if you enable [Stats for nerds] and right click on the video.
We do have a buddy system.. the tech and the inspector who signs the paperwork off. In 30 years of maintenance on aircraft..the inspector sometimes doesn't see errors..this happens alot. The copy method isn't approved by the FAA, so the management of the contractor is mostly at fault
What we do at work, on networks of computers, is to write the procedure and test it in a lab with the same equipment as production, send the procedure to a second team that reviews it and tests it on other lab equipment, then review the procedure on a call. When we implement things on the production systems, we're all on the call making sure the person executing the procedure is doing it correctly, and we handle any deviations in the production systems by backing out the procedure, fixing the discrepancy, then re-trying it. So sort of a buddy system, but in a long, drawn-out way.
When I watch these kinds of videos I can only think of all the flaws there are out there and we don't know yet
Great video. Sadly today if you see an error in maintenance, you can be treated as a Whistleblower.
Tragic how something that may seem so small ended up costing lives. May they RIP
Hi there,
An interesting video for me since I've been involved in Learjet airworthiness and modification for many years.
There IS a 'Buddy' system for maintenance technicians. It's tje Independent Inspection (also known as Duplicate Inspection). This is needed for all flight safety sensitive maintenance tasks.
Also, a technician that is licensed and allowed to sign must know what to do,and not just shown by someone else. That would be gross negligence.
I know that FAA rules are significantly more lax than EASA rules, but there is no justification for this, if the story is complete.
Incidentally, technicians are to write down the exact references to the wiring diagrams used and must work with the documentation at hand.
Thank you for the video. I will certainly look up the NTSB report and try to understand what happened with more details.
Cheers
Mark
Weeeeell, not to alarm anyone, but I saw this many times in the Air Force. In fact, it was done frequently enough that we had a name for it. We affectionately referred to it as a "Chinese blueprint." I even saw it at Boeing. They don't want to break a person loose to train someone. The person who could instruct was already miles away doing a new job. So the new person, with their trusty camera or phone takes a picture of a completed install and that's the "engineering drawing."
Audio levels were a little low on this video. Good work, and a good reminder to check *actual* diagrams before doing work.
I fix cars.
It is very common ‘can you have a look at this, it looks wrong…’ we ask each other.
We catch each other’s mistakes. We both have to be happy with ‘it.’
Fist bump. Well spotted.
When do we get a video about the collision at the 11:32 mark in this episode? 😀
You weren’t supposed to see that 😂
@@MiniAirCrashInvestigation Um, we're watching your channel, of course we're going to see that!
A pilot direct vision issue combined with local ATC control issue incident comes to mind watching that blip, I'd recommend covering the 8 February 2000 Zion, IL mid air collision between N5ZA and N99063.
"Big whoop" I have not heard that phrase since I was a teenager and that was in the 80s.
11:30 "Boss you've killed a child!"
Can you do a review on Cubana de aviación flight 455?
It crashed off the coast of Barbados on October 6th 1976
Honestly, I have been under the false impression that civilian aircraft modifications were peer-reviewed by competent, qualified personnel before recertification. Apparently not.
**This channel should be awarded “most improved” channel on UA-cam. When I subbed, there were just a couple thousand others and it was a bit unpolished especially on the video feeds. Great work!**
11:20 I'm a 7-level for egress on USAF F-35s, and that's exactly what we do for it. 5-levels will perform the work, and Red-X 7-levels will inspect the work - thereby taking responsibility for the maintenance performed.
You short out a battery, its internal resistance drops which, in turn, allows more current to flow which then drops the resistance again and so on until the battery eventually explodes.
very pog quality video
I would love to see you cover ValuJet 592!
The quality and skill of some of the people that end up working on airplanes can be down right scary. I used to work with a guy that worked for American Airlines, but he was working part time as a mechanic at the local Suzuki dealership. I thought the quality of his work was bad on ATVs and motorcycles. But the stories he'd tell about the work he did for AA was cause for alarm. He talked about how they'd cut corners on repairs, intentionally close something up before it could be inspected, substitute wrong parts, etc. I hope he was exaggerating, but I fear he wasn't.
I always copied my friends homework- should’ve realized things weren’t right, when we both failed🤷♂️
For some weird reason, this reminded me of an incident where Lockheed-Martin dumped an under-construction satellite onto the lab floor, doing millions of dollars in damage.
NOAA-19
"On 6 September 2003 at 15:28 UTC, the satellite was badly damaged while being worked on at the Lockheed Martin Space Systems factory in Sunnyvale, California. The spacecraft fell to the floor as it reached 13° of tilt while being rotated. The satellite fell as a team was turning it from a vertical to a horizontal position. A NASA inquiry into the mishap determined that it was caused by a lack of procedural discipline throughout the facility. While the turn-over cart used during the procedure was in storage, a technician removed twenty-four bolts securing an adapter plate to it without documenting the action. The team subsequently using the cart to turn the satellite failed to check the bolts, as specified in the procedure, before attempting to move the satellite. Repairs to the satellite cost US$135 million. Lockheed Martin agreed to forfeit all profit from the project to help pay for repair costs; they later took a US$30 million charge relating to the incident. The remainder of the repair costs were paid by the United States government."
No spark. Without a fuse or breaker, the wire just got hot, like the wires inside a toaster. It became it's own fuse. Eventually, probably quite quickly, it just overloaded to a couple thousand degrees and set anything near it on fire.
This is a common issue with people that wire up aftermarket stereos in their cars. Always have a fuse or breaker in line somewhere to prevent shorts.
Any major modification to an aircraft (something that affects the function of it as an aircraft) MUST be signed off by an Inspection Authority licensed A&P mechanic.
But how could adding 2 boxes affect the function of the aircraft as an aircraft?
I think the civilian FAA mechanics follow a two-person concept. I KNOW the Air Force does. I spent 11 years fixing airplanes in the USAF. I’ve been the technician, the inspecting technician, and a QA inspector.
300 amps? Tiny wire? That wire should be anything BUT Tiny!
UNPROTECTED WIRES
goodness. even in basic workman skill prog we had that covered.
Btw, wasn't there a supervisor who checked the work done ??
...yea little wrong about needing a spark. ive seen a transformer rectifier ground wire catch fire all because one phase was missing due to a loose connection. Too much power down a wire can cause it to heat up enough to case the insulation to catch fire.
Pretty much instantaneously too. Put an ordinary butter knife across the terminals of a car battery and it'll glow red hot within a second or two.
What you call a "buddy system" is already in place and has been for decades. In real life it's call QA or QC, as in Quality Control or Quality Assurance. Every airline or repair station I ever worked for has it, it's an FAA requirement. Besides that, no work can be done on any aircraft without using some type of approved data, such as maintenance manual, engineering drawing, manufacturer's specs, etc. How that company got away without all that is beyond me.
I think it's far more likely that the wire got hot enough to ignite the insulation at short circuit current, I don't know what voltage systems are on a plane, but judging from the high amps, I think it's like 24-48v max, where a spark jumping a gap over air would be really unlikely. But this is just my assumption, I'm no aircraft mechanic.
No, you're absolutely right. It doesn't take a spark to ignite insulation.
A SwissAir MD80 crashed once because of bad wiring of a new entertainment system for first class that intermingled with critical avionics in the cockpit and had no off switch. The jet dove into the ocean at 250 knots after cockpit temperatures hit 600 degrees F.
Standard practice in a factory, you NEVER inspect your own work. It would never have crossed my mind that aircraft maintenance was less stringent than sewn products.
Any way you can do TWA FLIGHT 128 that crashed in Burlington Kentucky?
I wonder how a buddy system would help.
Some work has to be done on in hard to reach area.
The job is not done, until the covers are installed and secured.
See where this is going?
Person A needs to do the actual job, Person B needs to sign it off, Person A needs to install the cover, Person B needs to sign it off... and then people start complaining about leaving half finished work in the hangar, causing missing work steps and misplaced mounting materials.
What I could imagine is photo documentation.
Actually there is something like that which requires 2 licensed technicians to perform the work to be done and under certain circumstances the second person is just there not to be involved in performing the work but only in checking the work is done properly by doing the test and inspecting the work.
An AIrman would have to sign off on the work (FAA form 8130-3). Unfortunately, it's fairly common for these Airman to sign-off without actually looking at the work - which isn't required.. That's probably the part that should change.
Actually you don't need a spark, overloaded wires burn houses down everyday just from being too hot, that's why you have to have larger gauge wiring for more high power situations. A short circuit is an easy way to heat up wire, just check out electric heaters. They can set things on fire too, no spark necessary.
Last word "Come on baby don't crash on me now!"
I'm surprised there is no "buddy system" as you call it. At our company there must always be an inspection from another person after the product has been mounted and tested. And we are not even in a safety critical field, it's just for quality control
Your voice is so good-can i i ask your age? Perfect anyway! Pasi-Finland