I understand that the ground worker is outside of the induction zone...But you've still got to give him a big balls award for standing in front of two 100,000 horsepower vacuum cleaners.
The inlet danger zones are, Engine Idle: 15ft (4.6m), Takeoff Power: 63ft (19.2m). The nose is around 23m in front of the intake, and the headset man is about 5m in front of the nose. You'll notice that though he may move around and stand on one leg while the engine is idling, once the power starts increasing his attention is firmly fixed on that aircraft. It's very unusual that this test is carried out without intake guards, my video description details why it was the case this time. Thanks
I know this video is from 9 years ago but it just popped up on my UA-cam. You say the inlet danger zone is 15ft at idle. I heard that a 737 at idle could suck a 200lb person into the engine from 30ft. Either way, it's a great video there.
I work at a logistics company a 100 meters away and often hear the engines runs, pretty awesome to witness these machines going through their tests. Keep up the great content.
I grew up in Harlington in the 80's and 90's when there were 2 engine run locations, so often we'd hear a symphony of loud gritty turbines, or a deep roar from Concorde's engine runs. Much louder back then than these modern planes but equally fascinating. My grandad was a BA engineer in the 60's and 70's so this would've been a common thing for him on those old smokers. What an awesome job.
He's standing there because it's company policy to have an observer in constant communication with the flight deck as with all engine ground runs. It is not possible to see the engines from the flight deck. He can inform the engineer performing the test of any problems earlier than the warning system. He will also notice if the aircraft moves before the flight deck crew. He is very aware that running engines are dangerous, and that's why he's standing well outside the inlet danger safety zone.
Why not install the fuselage buit-in angle cams to watch the engines from cockpit? We are now on that tech level. Frankly speaking Tired to always hear " We/They can't see the engines from cockpit" Cheers :)
@@WSOAWACS You would have to take that up with Boeing, we can't just go around drilling holes in aircraft to attach cameras to. Not to mention the wiring and configuration changes.
Fascinating! I really enjoy the look from the technical side. I have only ever seen the view from inside as a passenger. I very much appreciate this peek behind the curtain.
I been blasted by a 757, 767, 737, MD-88 and other engines many times working the airport ramp..... it feels like being hit with a strong gust of very (hot) air with a over bearing gasoline (jet fuel) smell. In the summertime in 90 -100 degree weather it just feels like your being cooked to death !
All vehicles brakes are more powerful than their engines ,next time you are bragging about your engine to your friends ,take a moment and show them your brakes
There's two ways that the spoilers will deploy automatically. On approach to landing the flight crew can move the spoiler/speedbrake lever to the arm position, they will then deploy when the "weight-on-wheels" switches sense the aircraft has touched down. If the lever is not in the arm position, the spoilers will auto-deploy when reverse thrust is selected. That's what happened here when the thrust reverser translating sleeves were tested at 1:32, hope that answers your question, TFW.
Hi, an engine run is carried out after each and every service check. It's done for leak checks and function tests of the systems that have been disturbed during the maintenance input. Some are simply idle runs and others are high power, it depends on what work has been carried out during the check. Running the engines makes sure adequate fluid pressures are attained. For example, fuel pressure can be as high 600psi at high power. Thanks for watching and good luck with your studies.
There are facilities at Heathrow too, this video was done there. 747, 767, 777, Airbus A320 family minor checks and 767 major checks are carried out at Heathrow. It's possible Airbus majors are done at Heathrow but I can't be certain. Thanks for watching.
Thanks for the uploads! Love your channel. Your babies go over my head every morning on the BA212... I can set my watch to it and can also always tell whether it's a G-VII- GE90 or G-YMM- RR going overhead... I'll have to send you some of my videos! The RR is the better sound imho
BA's first 777-200 were fitted with General Electric GE90 engines. Still, BA switched to Rolls-Royce Trent 800s for subsequent aircraft. For the 777-300er, the GE90 is the only option
Thanks for a great video....I have to laugh at those who think we are "heros" for standing in front of a test run..bloody cold some days and noisey as .ell but its got to be done.and no we wont get sucked into the engine unless we were standing in front of it, we carry laptops and communication equipment and if the plane does start to slide and the engineers didnt notice soon enough, we can cut engine power at ground level
Government of Facebook Messenger Department They press control alt delete 😂 joking aside I too have no idea but it must be a nice job to work on these beauties
Looking at the tires squatting, I can tell this bird is HEAVY with fuel for this run-up. I work at a local FBO where we do MX and run smaller GA aircraft up like Citations, King Airs Etc... It would be a blast to work with one of these.
+Riley Woods Not that much, 40 metric tonnes, Max is 95 tonnes on this "A Market" 777-200, which are the earlier ones, most 777-200s can hold 137 tonnes
I like my job but it's not all fun. Take de-panelling the leading edges of a 777's wings, that's at least 30 panels and they have a minimum of 32 screws each, to be removed with hand tools. Then the next day you have to put them all back on again! Or changing the filters on the toilet waste tanks, lovely. Or clearing a blocked drain line because cabin crew pour milk, coffee, wine, juice, and everything else down there and it coagulates and festers and you get to fish it out with a brush, Joy!
I noticed that 'strobe' effect of the camera just about stops the fans at their highest speed in this test - if this is a 30fps video then that makes it about 1800rpm? And I think we needed a few more leaves, sheets of paper, lost luggage etc flying around, to better illustrate the no doubt impressive set of vortices set up by this wonderful experiment. Thanks for uploading.
Yeah, we kinda have to make sure all that stuff is not in the run pen before running them up like this :). At 8:15 if you watch in full screen, at the rudder, there's a fair size chunk of snow that makes it way right (on screen) and is obliterated by the exhaust of the left engine, I like that ha. Thanks for stopping by and leaving a comment, appreciate it.
Physics, chocks are shaped in a triangle. The chock doesn’t move due to the friction contact it has with the ground. Also having all the wheels secured won’t make that plane move. Plus the parking brake is also used
Amazing ! I actually did enjoy that an wishing it was me standing there lol (one day) .. Some powerful brakes they are .. & do only take the engines upto 80% or can anyone be at 100% ??
thankfully the bird is anchored to the ground so that if the wheel brakes cant keep it from moving the anchored wheels will hold her still at full throttle
derek wall Each of the 12 mainwheels has a brake on the 777, each brake has 6 pistons which are pressurised with 3000psi hydraulic system fluid. The brake pack consists of 5 carbon rotors and 5 carbon stators. As a rough calculated guess, there is approx 54000lbs of force clamping the rotors and stators together on EACH wheel, they're telling the aircraft "you aint going nowhere mate" :)
If a take-off power test is required, which isn't very often, one engine would be run at full power and the other at 60%, then switch over to do the other engine at full power. This is normally also the case for this 80% thrust test. Due to the conditions, the engineer running the test decided it would be better that if the aircraft started to slide, it would do so in a straight line. That's also the reason there are no intake guards on this run and I'm standing right the way back there :) TFW!
How often do you need to do this routine?? I am educating myself as an aircraft mechanic and running the engines is one of those maintenance checks I think look coolest!
Great video! May I kindly request your permission to include this clip in my upcoming episode? Full credit will be given in both the video and the description. Thank you.
+LinusLarrabee Because he was standing outside of the induction zone. Even large jet engines that inhale tonnes of air per second only have a limited supply; per se. Just like your vacuum cleaner has technically enough power in it to kill you. But it just sucks wind.
I would love to have this job. Graduated in May of 2016 from the Aviation Institute of Maintenance, and received my A&P license. Unfortunately I can't find a job that doesn't require 3 - 5 years of experience.
just out of curiousity, why do the spoilers deploy? did the person in the flight deck deploy them, or does the aircraft deploy them through its own logic sensing it it on the ground?
The spoliers deploy automatically when reverse thrust is selected, which is part of the test. This ensures the thrust reverser systems works correctly after being reset as they are de-activated in the hangar for maintenance and safety.
When you work the ramp you are taught where to stand, and areas of the plane to not walk in front of, and behind when engine is running. Plus the areas by the engine are marked with danger line logos.
It would seem like you would need alot more than just a parking brake to hold it in place.. Like it should be strapped to the concrete or something...that's crazy but awesome af
After routine maintenance an engine ground run is carried out to check for leaks from serviced components. A run is necessary to build up the required fuel and oil pressure in the various systems. At 80% N1 speed (the fan rotor is N1) the fuel pressure is over 550psi. Once the run is complete the engine cowlings are opened and a thorough leak check is carried out, paying particular attention to any filters that have been changed, blanks and plugs that were removed for borescope inspections, and pipework that may have been disturbed.
the jet is chocked and before he runs ground they have a lil talk saying if the jet does jump chockes that he runs one way and they steer the jet the opposite.
I understand the brakes lock the wheels, but I'm surprised there is enough traction to keep the plane from skidding with wheels locked when engine is running full throttle.
thihal123 The maintenance manual states that the aircraft must be at a certain minimum weight to perform a high power engine run. We increase the aircraft weight simply by adding large amounts of fuel (40,000KG usually). This makes sure the tires are firmly planted onto the tarmac. Thanks for watching :)
Great video. Are there often leaks found and of so why? I didn't quite understand why no intake guards were required when two engines running, surely the danger is still present, or is it because an engineer can away more easily from a straight slide?
Thanks for the comment firstly. It's not very often we find leaks no, we're checking to make sure the filters and drain plugs we've changed aren't leaking, that's just good maintenance practices.
Question to you: do you know how much pressure builds up in the combustion chamber? I did the math, 550 psi is 3.8 MPa which is extremely high therefore the energy of the fuel and air combined is high therefore increasing rate of energy that converts to thrust. Temperatures must be hovering about 9000 degrees F, no wonder this engine is so efficient.
The GE90-76 is listed as having an overall pressure ratio of 40:1. That means on the ground at full power that pressure is around 580psi. Maximum pressure in the engine occurs after the last stage of the compressor, pressure actually drops a little in the combustion chamber as the gas is allowed to expand, further pressure drops occur through each turbine stage. If the combustor achieves higher pressure than the compressor outlet, then a surge occurs. I couldn't find combustion temperature, but the maximum turbine inlet temperature is listed as 2700 deg F. That's combustion air mixed with cooling dilution air, so it's reasonably hot yes.
Juan Ulloa The overall pressure ratio is the ratio between compressor outlet pressure and the outside, or ambient, air pressure. In this case, 40:1, the compressor outlet pressure is 40 times greater than ambient air pressure at full power I presume. In the description I mention the fuel pressure is 550psi, that is in the feed tube after the high pressure fuel pump to the fuel spray nozzles and so not directly related to compressor outlet or combustion chamber pressure.
dominique lachance Je suis vraiment désolé Dominique, je ne parle pas français. J'ai essayé de traduire votre commentaire en ligne, mais ce n'est pas très bon.
I understand that the ground worker is outside of the induction zone...But you've still got to give him a big balls award for standing in front of two 100,000 horsepower vacuum cleaners.
Correction: 100.000 hp snow blowers...
El Moli 100?
Or just crazy
i do it every week 🙃
Eugen 120.000 xD
Ahhhh. So that's how they keep the Earth rotating in orbit!
earth no does it roatate ites flat
What the hell? Read that again, but slowly.
@@aryanrishi No, it's not.
@@aryanrishi ffs
@@aryanrishi
Not surprised that u are dumb
The inlet danger zones are,
Engine Idle: 15ft (4.6m),
Takeoff Power: 63ft (19.2m).
The nose is around 23m in front of the intake, and the headset man is about 5m in front of the nose. You'll notice that though he may move around and stand on one leg while the engine is idling, once the power starts increasing his attention is firmly fixed on that aircraft. It's very unusual that this test is carried out without intake guards, my video description details why it was the case this time. Thanks
I know this video is from 9 years ago but it just popped up on my UA-cam. You say the inlet danger zone is 15ft at idle. I heard that a 737 at idle could suck a 200lb person into the engine from 30ft. Either way, it's a great video there.
@nicholasschwarz7663 Yeah let alone a GE90 the size of a 737 😅
Fart in the inlet
The blade fan rotation matching the camera refreshing speed was satisfying
looks like na zi symbol when rotating
Got a time stamp?
@@tryste_mx here you go 09:20
@AhmedSalam thanks!
I work at a logistics company a 100 meters away and often hear the engines runs, pretty awesome to witness these machines going through their tests. Keep up the great content.
I grew up in Harlington in the 80's and 90's when there were 2 engine run locations, so often we'd hear a symphony of loud gritty turbines, or a deep roar from Concorde's engine runs. Much louder back then than these modern planes but equally fascinating. My grandad was a BA engineer in the 60's and 70's so this would've been a common thing for him on those old smokers. What an awesome job.
THe 777 with those big chunky engines is the most beautiful plane currently flying.
I love the start up of those engines the low groan then the up tune of sound just awesome
That is a very good way to clear the snow off my yard and house, now all I need is a plane.
He's standing there because it's company policy to have an observer in constant communication with the flight deck as with all engine ground runs. It is not possible to see the engines from the flight deck. He can inform the engineer performing the test of any problems earlier than the warning system. He will also notice if the aircraft moves before the flight deck crew. He is very aware that running engines are dangerous, and that's why he's standing well outside the inlet danger safety zone.
Why not install the fuselage buit-in angle cams to watch the engines from cockpit? We are now on that tech level. Frankly speaking Tired to always hear " We/They can't see the engines from cockpit" Cheers :)
@@WSOAWACS You would have to take that up with Boeing, we can't just go around drilling holes in aircraft to attach cameras to. Not to mention the wiring and configuration changes.
@@mrifixplanes1813 Clear. Thanks
and it looks like that is as far as the cord goes..
You never stand in front of an aircraft that is doing full power. You can stand off to the side and the warning systems are there for a reason.
Wow! The 777 is a real star and I'm a real fan of it! Thanks for posting it here.
Fascinating! I really enjoy the look from the technical side. I have only ever seen the view from inside as a passenger. I very much appreciate this peek behind the curtain.
My dream is that after I graduate with my mechanical engineering degree, I will get hired by GE Aviation to engineer these engines.
good lock
pavel1809
nah why would he purchase a lock.
No one goin anywhere.
I have the same dream
Start to thing about 9X
3 years later, mission accomplished?
waking behing that plane woud send you on a HELL of ride.
I been blasted by a 757, 767, 737, MD-88 and other engines many times working the airport ramp..... it feels like being hit with a strong gust of very (hot) air with a over bearing gasoline (jet fuel) smell. In the summertime in 90 -100 degree weather it just feels like your being cooked to death !
Have you been at St. Marteen Airport?. It is a blast.
@@hectormelendez7196 Do you smell the fuel?
@@lagdroid0017no shit Sherlock
thats some powerful ass brakes
The plane is strapped to the ground.
vector6977 no they are brakes.
All vehicles brakes are more powerful than their engines ,next time you are bragging about your engine to your friends ,take a moment and show them your brakes
those are brakes and wheel chocks
Some aircrafts have a thrust to weight ratio greater than the weight of the aircraft. Even with breaks applied they'll still move forward.
There's two ways that the spoilers will deploy automatically. On approach to landing the flight crew can move the spoiler/speedbrake lever to the arm position, they will then deploy when the "weight-on-wheels" switches sense the aircraft has touched down. If the lever is not in the arm position, the spoilers will auto-deploy when reverse thrust is selected. That's what happened here when the thrust reverser translating sleeves were tested at 1:32, hope that answers your question, TFW.
Yes! Squat switches control many systems
Hi, an engine run is carried out after each and every service check. It's done for leak checks and function tests of the systems that have been disturbed during the maintenance input. Some are simply idle runs and others are high power, it depends on what work has been carried out during the check. Running the engines makes sure adequate fluid pressures are attained. For example, fuel pressure can be as high 600psi at high power. Thanks for watching and good luck with your studies.
Brakes and chocks holding back 230,000 lbs of thrust. That’s wild.
Looks like there are at least 160 of us who are 'that way inclined'.....
Love it!
Thoroughly glad you're all enjoying it. Thanks for the comment.
The Boeing 777: the only plane that would suck your house up & pretend it was a bird strike
I can see the dollars being blown out of the exhaust! :-o
I love these engines....so big and exasperated new size! Awesome!
New size....?
Handy for clearing the drive after a snowfall
There are facilities at Heathrow too, this video was done there. 747, 767, 777, Airbus A320 family minor checks and 767 major checks are carried out at Heathrow. It's possible Airbus majors are done at Heathrow but I can't be certain. Thanks for watching.
The best concert hall ever!
God save the King BA.
Thanks for the uploads! Love your channel. Your babies go over my head every morning on the BA212... I can set my watch to it and can also always tell whether it's a G-VII- GE90 or G-YMM- RR going overhead... I'll have to send you some of my videos! The RR is the better sound imho
Hey, thanks for your comment, really appreciated.
Who needs a snow plough when you can get a Boeing 777 :)
Love this....i do this in P3D for ages just listening to the whine.... great to hear the real thing....
I just love that sound.
Airplane of the year 1995!
I thought British Airways only used Rolls Royce powered 777's, glad I was wrong. GE90 cant be beat, its a beast of an engine.
ge90 only option on 777-300er
BA's first 777-200 were fitted with General Electric GE90 engines. Still, BA switched to Rolls-Royce Trent 800s for subsequent aircraft. For the 777-300er, the GE90 is the only option
@alioumaiga6116 Thanks for that, makes more sense now.
You guys have the best jobs!!! No lie!! I am tired of driving a Peterbilt! I want to be closer to jets at Ohare!!
Great vid mate.👍
i know how shaky it is in the cockpit when it comes to high power runs. 😫
I'm glad they have that guy there to stop the plane from jumping forward , like has happened !!!!!
Thanks for a great video....I have to laugh at those who think we are "heros" for standing in front of a test run..bloody cold some days and noisey as .ell but its got to be done.and no we wont get sucked into the engine unless we were standing in front of it, we carry laptops and communication equipment and if the plane does start to slide and the engineers didnt notice soon enough, we can cut engine power at ground level
compteck7 I know this is a late comment, but how do you cut the engines at ground level?
Government of Facebook Messenger Department They press control alt delete 😂 joking aside I too have no idea but it must be a nice job to work on these beauties
You're very welcome, and thanks for watching!
Thanks for uploading :)
Sounds like warp drive kicking in @ 1:00! :)
That video made my day, thanks!
What a beauty the 777
♥️I agree♥️
A brave man to be standing that close! Not me!! I'd be back where the photographer's at.
the 30 dislikes were from train lovers. awesome video!
my icon in maintenance action :) !!!!
Imagine having this as your snow blower... can clear an entire street from the intersection.
Looking at the tires squatting, I can tell this bird is HEAVY with fuel for this run-up. I work at a local FBO where we do MX and run smaller GA aircraft up like Citations, King Airs Etc... It would be a blast to work with one of these.
+Riley Woods Not that much, 40 metric tonnes, Max is 95 tonnes on this "A Market" 777-200, which are the earlier ones, most 777-200s can hold 137 tonnes
I like my job but it's not all fun. Take de-panelling the leading edges of a 777's wings, that's at least 30 panels and they have a minimum of 32 screws each, to be removed with hand tools. Then the next day you have to put them all back on again! Or changing the filters on the toilet waste tanks, lovely. Or clearing a blocked drain line because cabin crew pour milk, coffee, wine, juice, and everything else down there and it coagulates and festers and you get to fish it out with a brush, Joy!
Nice how the framerate matches the N1
@ 1:35 u could see the air being ingested into the engine inlet on engine #1. left side
I think the guy in the green vest must wear a warmer jacket this winter
Just my kind of snow plower!!!
There’s having big balls then there’s that man
What a howler!
almost 200,000 lbs of thrust right there... that's about 7 of the F-15E engines at full afterburner...
Luckily no one was injured
Nice of you to say so, cheers
please! i want my turbo to sound like this in my car :))))
then remove the internal combustion engine and install one of these :v
British Airways Maintenance Center at Cardiff Airport ?
I don't think I'd be able to stand there so calmly in front of a 777 while its running.
Never work the ramp please😂
If you want some perspective, the diameter of these engines is about the same diameter as a 737 fuselage.
I noticed that 'strobe' effect of the camera just about stops the fans at their highest speed in this test - if this is a 30fps video then that makes it about 1800rpm? And I think we needed a few more leaves, sheets of paper, lost luggage etc flying around, to better illustrate the no doubt impressive set of vortices set up by this wonderful experiment. Thanks for uploading.
Yeah, we kinda have to make sure all that stuff is not in the run pen before running them up like this :).
At 8:15 if you watch in full screen, at the rudder, there's a fair size chunk of snow that makes it way right (on screen) and is obliterated by the exhaust of the left engine, I like that ha.
Thanks for stopping by and leaving a comment, appreciate it.
Incredible! 🔥🔥🔥
Curious. Why doesn’t the enormous thrust propel the plane forwards over the chocks etc.
Physics, chocks are shaped in a triangle. The chock doesn’t move due to the friction contact it has with the ground. Also having all the wheels secured won’t make that plane move. Plus the parking brake is also used
@ thanks
servicing Waste Separators, good times...not
EGR's are one of my favorite things about the job
Notice how by the end of the video the blast walls are almost completely swept clean of snow.
Amazing ! I actually did enjoy that an wishing it was me standing there lol (one day) .. Some powerful brakes they are .. & do only take the engines upto 80% or can anyone be at 100% ??
Excellent video.... must have good brakes or that thing would have been off like a shot!
Using the world's most powerful jet engine to clear the snow
Enjoyed very much!
Thanks
thankfully the bird is anchored to the ground so that if the wheel brakes cant keep it from moving the anchored wheels will hold her still at full throttle
derek wall No anchors, just brakes, and chocks placed near to the wheels.
MrIfixplanes really I hope they'll be enough. the sound the engines are making is the aircrafts way of saying I want to fly please let me fly
derek wall Each of the 12 mainwheels has a brake on the 777, each brake has 6 pistons which are pressurised with 3000psi hydraulic system fluid. The brake pack consists of 5 carbon rotors and 5 carbon stators. As a rough calculated guess, there is approx 54000lbs of force clamping the rotors and stators together on EACH wheel, they're telling the aircraft "you aint going nowhere mate" :)
MrIfixplanes cool. im sure the ground crew feel safe now
Can't the plane create enough thrust to break traction of the 14 tires, or is that just too much force required.
THIS WAS AWESOME!!! Thank you!!!
+MikeVonDoom You're welcome, thanks
Look at the tornadoes they created
Is it just parking brakes and chocks that stop it taking off
I don’t understand the explanation for no intake guards in the video description, just curious, cheers!
If a take-off power test is required, which isn't very often, one engine would be run at full power and the other at 60%, then switch over to do the other engine at full power. This is normally also the case for this 80% thrust test. Due to the conditions, the engineer running the test decided it would be better that if the aircraft started to slide, it would do so in a straight line. That's also the reason there are no intake guards on this run and I'm standing right the way back there :) TFW!
Is all of BA's maintenance done at Cardiff or do they have facilities at Heathrow as well? Thanks for the behind the scenes look.
Unleash the beast!!
How often do you need to do this routine?? I am educating myself as an aircraft mechanic and running the engines is one of those maintenance checks I think look coolest!
The reverse test was what one should expect.
Great video! May I kindly request your permission to include this clip in my upcoming episode? Full credit will be given in both the video and the description. Thank you.
Please don't get too close to that engine!!! That sounds is music to my ears!
Looks like BAMC. My son Sam will be applying for an apprenticeship there in 2014 after work exp in Oct '13 :)
I need a front row seat to this every time the need to do turns on a 777
Expect nothing less from the Flagship ‼️‼️‼️‼️
Fuel pressure 550 psi. In my VW Golf it's nearer 30,000 psi!
Nice vid, colleague! ;)
6:39 Speedbird..Go at throttle up.
Nice video! How is it that the engine did not suck that man up?
+LinusLarrabee Engine ingestion can only happen in closer proximity to the engines. Standing behind the nose wheel will become risky though
+LinusLarrabee
Because he was standing outside of the induction zone. Even large jet engines that inhale tonnes of air per second only have a limited supply; per se.
Just like your vacuum cleaner has technically enough power in it to kill you.
But it just sucks wind.
I would love to have this job. Graduated in May of 2016 from the Aviation Institute of Maintenance, and received my A&P license. Unfortunately I can't find a job that doesn't require 3 - 5 years of experience.
gotta job yet? also how hard is it to get an a&p im currently surving in the usaf and am planning to get one myself.
just out of curiousity, why do the spoilers deploy? did the person in the flight deck deploy them, or does the aircraft deploy them through its own logic sensing it it on the ground?
excellent videos
WTF the ground worker is doing near the induction zone ?
AWESOME AWESOME AWESOME. MORE PLEASE
it cleans like a vacuum
If his foot sips off the clutch the guy on the ground is sure gonna be surprised!
if they are running at full or even 80%, how do they keep they plane still?? And how is the guy not sucked into the engine?
Just set the parking brake, they're strong enough to hold the power. TFW.
The spoliers deploy automatically when reverse thrust is selected, which is part of the test. This ensures the thrust reverser systems works correctly after being reset as they are de-activated in the hangar for maintenance and safety.
When you work the ramp you are taught where to stand, and areas of the plane to not walk in front of, and behind when engine is running. Plus the areas by the engine are marked with danger line logos.
It would seem like you would need alot more than just a parking brake to hold it in place.. Like it should be strapped to the concrete or something...that's crazy but awesome af
Looks like it might have a chock in front of the nose wheel too.
Amazing !
What's the meaning of letting the engines run like that? Is there any thought behind it? If yes, which one?? :)
After routine maintenance an engine ground run is carried out to check for leaks from serviced components. A run is necessary to build up the required fuel and oil pressure in the various systems. At 80% N1 speed (the fan rotor is N1) the fuel pressure is over 550psi. Once the run is complete the engine cowlings are opened and a thorough leak check is carried out, paying particular attention to any filters that have been changed, blanks and plugs that were removed for borescope inspections, and pipework that may have been disturbed.
MrIfixplanes Thanks a lot for this detailed answer! 😀
To check if the engines are running properly. If there's a problem, it will show itself otherwise .
What if the brakes come loose....
the jet is chocked and before he runs ground they have a lil talk saying if the jet does jump chockes that he runs one way and they steer the jet the opposite.
I understand the brakes lock the wheels, but I'm surprised there is enough traction to keep the plane from skidding with wheels locked when engine is running full throttle.
thihal123 The maintenance manual states that the aircraft must be at a certain minimum weight to perform a high power engine run. We increase the aircraft weight simply by adding large amounts of fuel (40,000KG usually). This makes sure the tires are firmly planted onto the tarmac. Thanks for watching :)
The engines only reach about 70% power in this video. Full power ground run ups are rarely done.
Great video. Are there often leaks found and of so why? I didn't quite understand why no intake guards were required when two engines running, surely the danger is still present, or is it because an engineer can away more easily from a straight slide?
Thanks for the comment firstly. It's not very often we find leaks no, we're checking to make sure the filters and drain plugs we've changed aren't leaking, that's just good maintenance practices.
Question to you: do you know how much pressure builds up in the combustion chamber? I did the math, 550 psi is 3.8 MPa which is extremely high therefore the energy of the fuel and air combined is high therefore increasing rate of energy that converts to thrust. Temperatures must be hovering about 9000 degrees F, no wonder this engine is so efficient.
The GE90-76 is listed as having an overall pressure ratio of 40:1. That means on the ground at full power that pressure is around 580psi.
Maximum pressure in the engine occurs after the last stage of the compressor, pressure actually drops a little in the combustion chamber as the gas is allowed to expand, further pressure drops occur through each turbine stage. If the combustor achieves higher pressure than the compressor outlet, then a surge occurs.
I couldn't find combustion temperature, but the maximum turbine inlet temperature is listed as 2700 deg F. That's combustion air mixed with cooling dilution air, so it's reasonably hot yes.
MrIfixplanes But when you say ratio pressure is 40:1, means exactly what? What pressures are being compared?
Juan Ulloa The overall pressure ratio is the ratio between compressor outlet pressure and the outside, or ambient, air pressure.
In this case, 40:1, the compressor outlet pressure is 40 times greater than ambient air pressure at full power I presume.
In the description I mention the fuel pressure is 550psi, that is in the feed tube after the high pressure fuel pump to the fuel spray nozzles and so not directly related to compressor outlet or combustion chamber pressure.
dominique lachance Je suis vraiment désolé Dominique, je ne parle pas français. J'ai essayé de traduire votre commentaire en ligne, mais ce n'est pas très bon.