- Greg's Airplanes = THE airplane history and technology guy! - Forgotten Weapons = THE small arms history and design guy - Chieftain's Hatch = THE tank guy - Drachnifinal = THE naval history and technology guy. There's many other really good people that cover these topics but those folks are the absolute master's in their fields for their technical knowledge, resource finding skills, presentation style, and ability to formulate the technical and historical information in a way that's easy to understand without being dumbed down. Kudos!!!
I agree with all, and watch every video, from all of them. But about tanks, i would say The Tank Museum, with David Fletcher in particular, is my tank and military vehicle channel! TIK is also a very very good historical channel, highly recommended!
Not to mention that these channels actually affect the way history is studied! Sinking of the hood was good as well as the Japanese attack thwarted by 2 small aircraft carriers... my personal favourite was in this channel when Greg proved that fighters DID have the range to escort bombers and the p51 story was spun so the public didn't string the bomber Mafia up by their thumbs
Greg, you consistently break down complex mechanical and engineering issue down to just the right level. Your explainations are spot on. Thanks for that.
"This is a simplified diagram. The actual diagram looks like the circulatory system of a small mammal .... which is to say its highly complex. But for our discussion..." Must rate as the most eloquent word-picture *ever*. Just poetry. With a *very* sharp focus on the factual. Excellent.
It's been nearly 40 years since I took my fundamentals of flight class in college so I've basically forgotten most of that stuff. Greg does a good job of explaining things.
I am a Registered Nurse and low time pilot. (No engineering background). Greg is a like some of the great professors that I had. He presents the information in such a manner that I often see the answer coming and before he makes the point. making me feel as if I solved it myself. Great job.
I have no idea how I stumbled on this channel, but it taught me more about the importance of engineering and math what 11 years of Russian school and college! Greg has the talent to be a teacher! Best lectures ever!
Heh heh, prop failures may be rare now, but one almost happened to me! It was in a Rans S3 at my flight school with a carbon fibre prop. It was the oldest plane at the school with various miner gremlins and rattles and no-one liked that thing. The last two registration letters were Quebec Whisky and we called it “Quebec Fix-Me"! I eventually heard it got totaled when one blade delaminated in flight, shortly after takeoff. They still had some thrust, so the instructor took over and made a 180 back to the runway. He very nearly pulled it off, and would have made it if there hadn't been a power line in the neighboring farm right at the edge of the field. (airfield owner had told me it was basically a spite wire. No comment) Instructor was okay, student got miner injuries (he went to a different school after that) but that airplane was a sculpture! I saw it a few days later and never have I seen a more bent airplane that wasn't in pieces. The punchline came weeks later when I was bored in the office and happened to pick up the logbook for old Quebec Fix-Me. I looked down to the very last entry, and there was my name! I missed that ride by a few minutes worth of engine time!
Are they supposed to be xrayed after an amount of hours? A friend had a prop from a cessna on his wall that looked fine, but apparently failed its xray test hence how he got it cheap. Maybe thats just an australian law?
@@Colt45hatchback I don't think general aviation props get xrayed in service. He probably means that it failed an xray during manufacturing so it couldn't be sold as an airplane propeller in the first place.
@@TonboIV that makes sense, the paint was all intact, and i recall an alloy, or maybe stainless steel plate about 2-3mm thick and probably 3"x1.5" in size bolted to the outside of the centre of the prop between the blades and possible slightly toward the outer edge affixed with two large phillips head screws with something written/stamped in it, i cant remember if it was a date or if it said not for service or what. But i remember thinking that doesnt look like it would stay there with the engine vibration. So youre probably right it may have not passed qc inspection at the factory
Evidently the flight school was lax in it's maintenance because carbon fiber propellers require more maintenance than metal propellers, though that's true of all plastic propellers (carbon fiber is a variant of plastic)
Great stuff My dad flew F4s, F4Us, F6s and others in WWII His comments on the props, each had their own issues The electrics would short out now and then and go into high pitch. The hydraulics would some times lose a seal and you’d get a oil spray on the windshield. He crashed a F4 went the prop went into high pitch on takeoff. Funny the story’s you remember.
I remember, as a child, in the mid-1950s being taken for a look-around in a local 'Old Curiosity Shop' in Watford. On the floor was a huge, four bladed wooden propellor with curved tips and transfers spelling 'Maurice Farman'. The price was £3.10/- (£3.50). That was probably my father's weekly wage at the time so it remained in the shop! I have never forgotten it and my child's eyes took in and retained all those details too.
Greg, as someone who went to A&P school in the 70's, took many a class on Hamilton Standard props, and had the opportunity to work on them, I have to say that you've posted an excellent explanation of the principles involved. The only problem with hydraulic props is that they are so reliable that many in the industry take them for granted. Bravo again my friend! You boil complicated subjects down so that the uninitiated can understand these complex systems. I've referred my apprentice to your videos as you explain these things very well.
So basically the magic of the speed regulator is a Watt regulator re-imagined, got it. This is hands down the best channel for people that love aviation and mechanical gizmos, so I challenge Greg to explain the mechanism for a constant speed contra-rotating propeller! Or the mast of the Ka-50/52 that I assume accomplishes the same function.
In a previous life I repaired and/or modified high performance props for racing and recreational boats. To get the most out of props in any given application was a combination of math, theory, compromise and voodoo. I found this video fascinating. Thank you!
Thanks for the video. You finally made me look up the plant my Mom worked in. Frigidaire built propellers for multi-engine aircraft, but also built components for the Aeroproducts props.
Thanks Greg. I have used Controllable pitch propellers on Type 42 destroyers (Ships) which have a lot in common, although they are fully reversible and we did not run them at constant speed. Thy hydraulic systems you showed are familiar and I thought you did a great job of explaining them. Thanks for sharing.
Odd that you should mention this. My neighbor has ordered a variable-pitch marine prop from a company in the UK. He’s still waiting because it’s delayed in customs, but he showed me technical information that has a great deal in common with these aero props. I need to take a closer look.
The same sort of system was used in powers station and marine turbine power control. These run at constant speed but use the governors to move the steam throttle valves. They have built in positive feedback and control damping back to reduce oscillation and ultimately speed runaway. The issue with all of these systems is the potential for runaway where the governor goes into oscillation between full open and full closed. When that happens it’s the same effect as fully open. In a power governor you get max power runaway in a speed governor you get over speed.
I enjoy how Greg can make an esoteric topic such as prop pitch, and give us an exoteric explanation that makes it much more clear. Good job Greg, and looking forward to the next edition.
This is amazing. I had no idea that power was controlled by changing the pitch and throttle/ manifold. I thought the pitch was constant and only the throttle was used. I also didn't know why the p-47 had different nose cones. Now it all makes sense.
Just have to say, I sort of envy the man who first developed a mechanical governor like this (which I suspect might have been on a steam engine or even before that), and could observe his invention in action for the first time. Super elegant device in my eyes, simple and sooooo useful in every imaginable spinning machine!
Quite a few things have this type of governor. Old wind-up Victrolas to maintain turntable speed and single phase electric motors to disengage the startup windings to name two.
@@GregsAirplanesandAutomobiles en.wikipedia.org/wiki/Centrifugal_governor It seems governors of this type (in general layout at least) even pre-date steam engines!
@@GregsAirplanesandAutomobiles A steam engine governor uses exactly the same principle, and was undoubtedly the inspiration for this governor. This steam governor was invented by James Watt - in 1770!
Wow, that was everything *I'd never realised I wanted to know* about early-mid 19th century propeller pitch control! I'm not even being facetious; I enjoyed that immensely, despite only having a passing interest in these subjects. Thanks!
@@givenfirstnamefamilyfirstn3935 yes yes very good you identified my typo. I did indeed mean *20th* century, obviously (I do understand how that naming convention works - although it is prime for encouraging such mistakes!)
Greg- Thanks for this propeller series. It hits home for me personally as my father was "radio" on C-46 Curtis Commandos flying the "Hump" in late '44-'45. He had related this aircraft was sent to do its job way before it was perfected. The two most common problems being leaking hydraulics, and problematic Curtiss Electric props. It was my understanding if an engine was malfunctioning, many times the prop would not feather. Anyway, I am proof he made it through. Love your channel.
Both the Spitfire and Hurricane were fitted with constant-speed units in the field actually during the BOB. Engineers from De Havilland toured RAF bases teaching ground crews to fit them - if it's stupid but it works, it isn't stupid.
Yes. Greg mentioned that in the video. I recall a wild claim about a dozen years ago claiming German pilots were surprised by the performance of Spitfire in the B.o.B, saying it was the new 100 octane or something. However, I think you and Greg are correct- de Havilland engineers and mechs went around those bases and retrofitted constant speed/vari-pitch props on the a/c. spitfiresite.com/2010/06/battle-of-britain-1940-constant-speed-propellers.html
@@orcstr8d I worked at HSDE on the Hatfield Airfield site for HSDE in the 1970/80's. One of the people I worked with was John Powell Williams a De Havilland Apprentice who in the 1940' went round the Airfields showing RAF Engine fitters how to it the Consant Speed Proppellors
Hi Greg, enjoy your presentations --- In 1954 I was stationed at Hickam field, territory of hawaii in USN squadron VR-7 -- our bird was the R7 v or super constellation -- This was one of the first applications of reversing propellers. The prop was Ham std 43E 60 -- and was giving a bit of problems-- I worked in engine build-up and change but props were my responsibility -- In short, the internal spider support block were failing and we went through at least 4 modifications before a satisfactory solution was found. In two years I disassembled, modified, re-assembled and tested more props than the average mech would do in 20 years. I think I could still take that prop apart today -- The governors were pretty trouble free, in operation they worked pretty much like a governor on a steam engine but with very precise tolerances ---
Great info on the workings of the constant speed prop. Re the metal prop blade thing, the Brits used a wooden composite called Jablo until the end of the war. I can't recall seeing them used other than on Spitfires, and not at all before the MkV in early 1941. You can see pics of Spit IXs crash landed in Normandy with their wooden prop blades shattered instead of bent. It's very distinctive. These were Rotol props (a company set up by Rolls Royce and Bristol).
IF U HAVE A PROP STRIKE WITH A WOODEN PROP, YOU PUT ON A NEW PROP.IF YOU HAVE A PROP STRIKE WITH A METAL PROP, THE ENGINE MUST BE TORN DOWN, AND THE CRANKSHAFT "RUN OUT" TO CHECK FOR TWIST.
My step-grandfather was RAF groundcrew in WWII. He said that early electrical controls for propeller pitch needed frequent pilot attention in climb or dive. The cause was change in resistance of wiring with temperature. This problem was solved later in the war by substituting a graphite conductor for a certain length of wire. The temperature coefficient of resistance of graphite is negative, while that for copper is positive; graphite and copper wiring could be connected in series so as to give the same resistance at any temperature.
Nicely done Greg. Cleared up a few things I had heard of but had never seen a thorough diagram of the system and the way they could be adjusted. Ingenious buggers back then. Loving that Corsair mug!
Wish the Internet had been around when I did Commercial Pilot Ground School in 1982. This video would have been quite handy. Never flew anything with a Hamilton Standard CSU as everything I flew had the Mccauley CSU; basically same thing, different name. *Thanks Greg,* that video took me back a few years to happier times. Much appreciated. 👍 CAVOK and tail winds.
Thank you so much. Fantastic video Greg! This is a topic lots of us warbird geeks have always wondered about and have seen very little in the way of entry-level information about. Excellent video! Can’t wait for part 3 tomorrow.
I did some experiments with fixed pitch prop in dcs. I used P-47D-30 for this job, because obvious reason, curtis electric prop. I tested couple pitch settings minimum pitch, climb pitch,cruise pitch. Take off with minimum pitch. I apply full throttle(i did not use turbo at all for all tests), first it looked fine but as i gained speed rpm pass 2750 red mark, i was forced to retard throttle, at moment when i lift off MP was 30inch. Top speed was 150-160 with small engine overspeed 2800rpm. Max MP below 25inch. Then i tested higher pitch settings, they improved flight top speed, but take off roll get ridiculous long, making impossible to take any combat load. Conclusion fixed pitch for P47 is not an option. I had so much fun testing that.
The Rhodesian Air Force used mark 22 Spitfires well after WW2. They stopped using them when shrinkage of the wooden prop blades due to the dry climate caused problems. Most model Spitfires seemed to have wooden blades, but some were fitted with metal blades in some theatres. I have a prop blade from a mark V and also a mark XVIII Spitfire….both wooden.
Looks like they got a "monkey model" version - far as I know UK mk.9 onwards at least had metal constant speed or metal variable pitch props. Mk22 with wooden props, someone got conned.
As usual a very interesting video! I knew quite well the difference between Hamilton Standard and Curtiss Electric propeller as well the Aeroproducts Propellers. All three companies produced lot of propellers during the 2nd WW and postwar. Generally speaking it was due to the efficiency of the propellers that permitted the airplanes to achieve their performance. A fascinating story indeed and thanks for doing a great job again 👍👍
Wonderful, as usual. Same applies to the Wright vid. You manage to be entertaining and thorough, a really rare combo of erudition and clarity. . Parece que hablas Espanol tambien. Hace dias estaba haciendo maromas en un Stearman equipado con 985, 2D30, sistemas por vuelo invertido y 4 ailerones. Pensaba en Ud en cada barril.
Superb, Greg. A clear, fascinating and straightforward explanation of prop control. All new to me other than the names. I'm just coming up on my 3 score and 10 but new knowledge is just as exciting as when I was 7 rather than 70. Thank you.
I've been a flight instructor for 50 years and explaining a constant speed prop has never been easy. Some people will intuitively understand it, some won't. There's no substitute for actually flying a constant speed prop to understand how it's used.
Thank you, thank you thank you for doing your best to correct the common misunderstanding about Lindbergh's flight. I am _constantly_ correcting people on it. You might be surprised to learn that the Battle of Britain included engagements over Wales, N. Ireland and even Scotland. So it would be correct to say the Battle of Britain was fought over Britain as opposed to England. I watched a DCS fight where a Sopwith Camel went against Fokker Dr.I over several rounds. It confirmed to me something I had read many years ago. The Dr.I got it's maneuverability more than anything else from it's fully floating rudder. You can see it here at 1:49 and compare it with the Albatros D.V at 2:17. where a fixed vertical stabilizer is visible with the rudder attached. I know it's a sim, so it can't be perfect, but Greg, you really should see that Dr.I flip around the sky. It's astonishing. It's called A Gentleman's Dogfight and it's by Growling Sidewinder.
Hi Greg! I need to offer some feedback from my time flying warbirds: Spit, Hurricane and Bf-109. I check out on the Brit aeroplanes first, and came to love their seemingly modern constant-speed props. Operating a Merlin is nearly carefree. The Bf-109 shocked me because it didn't have an operating C/S prop. In fact, it had an electrical prop control box on the floor, but consistent with its 1941 configuration, the restoration team lock-wired it OFF. In lieu of a "modern prop," there was a tiny propeller pitch toggle switch on the throttle, and a pitch indicator on the panel. What a mess! My warm-up routine in the RAF types started with a 1500 foot tall wingover from cruise power. Big speed changes resulted in big propeller pitch changes, but the pilot is blissfully unaware. In the 109, the airspeed changes caused the engine speed to bog down terribly, and it was barely able to achieve the maneuver. Manually regulating the prop pitch to control engine speed helped, but it was an "eye magnet" in the cockpit. I was appalled. I think that Luftwaffe pilots either (a) spent more time looking into the cockpit than ideal, (b) learned to roughly regulate the engine by sound, or (c) thrashed their poor engines when too busy to fuss with them. Maybe all of the above. Such differences are often overlooked, but the effect was not subtle. Great videos! Thanks!
I k ow absolutely nothing about this subject but... I was having dinner with a good friend who told me that his brother made propellers for classic airplanes, it was what he did for a living. He mentioned that his brother had by some chance found the original specifications for a spitfire propelled in some old factory that was shutting down. I seem to remember being shown some press coverage on the phone. He also said that the propeller was not wood or metal but some composite laminate material. No idea what. I completely trust this chap and it was the first course so in fairly sure I understood. Might be worth looking into.
Some Spitfires used wood fibre and synthetic resin blades. I tapped a Mk IX prop blade a while back and it felt tacky like ‘araldite’ epoxy resin glue. The only replacements are manufactured in Germany. Allegedly (!) prop strikes are less traumatic as the blades abrade more with less shock loading than with a sudden shatter or bend.
Seems that we now have a UK company allowed to make propellers. en.m.wikipedia.org/wiki/Hordern-Richmond. Interesting. It’s a wood laminate called Hygdulignum. www.goodwood.com/estate/estate-news/blades-of-glory/
I’m not sure I understand all the engineering nuances (I’m not an engineer or pilot), but this DOES explain why it might have been a minor miracle that my Dad’s F6F (Hamilton Standard prop) made it back to the USS Lexington in October, 1944 after a 20mm round from Japanese ground fire peeled away a good portion of the prop hub. He reported that the engine ran “rough but cool” on the (purposely) low-speed return trip, with oil pressure down to 10 lbs. by the time he landed. In the photo I have, the front of that big P&W behind the mangled hub was thoroughly covered in oil.
I think your Dad's incident reinforces the default position of a damaged pitch control should be in landing mode. My Dad had problems with Curtiss Elec. props flying the hump in C-46's. thanks for this good story.
I like to think of constant speed props as being like a cvt transmission for the air. Of course a lot of cars with cvts do it in steps which is ridiculous, but snowmobile transmissions harness the engines power in a very similar way. The engine can be tuned to make peak power at one specific rpm, and the cvt makes sure that the engine is always at that rpm when the throttle is wide open, except when nearing top speed of course.
I was told that the CVTs were made to shift in steps because it was felt that people would not trust a transmission that they could not feel shifting .
Great video Greg .....I always wondered how the constant speed prop worked. Just like you always do, you made it simple to understand. You are smarter than the average bear, but you have a knack for dumbing things down to allow us average Joes to get it. Take Care Stay Healthy Jerry
As I understand it the Rotol prop which the British used quite widely in WWII was a wooden core with a plastic skin, where the leading edge was reinforced with a brass strip. I assume this was a wartime expediency but they seemed to work, considering they were used on the later Griffon Spitfires too.
This is essentially what MT propellers are today. These are high-end german made props that are used on a lot of modern GA aircraft as well as replica warbirds...
Hi. Very informative as always. I have just one correction? I believe the Wright crash was the result of the propeller shaft failing not the actual prop.
Thank you for the info overload! I always wanted to know how exactly aerodynamics for props and etc worked. I have Aspergers and appreciate the details. Again thank you
wrt the Hamilton Standard prop, I think that the short summary is that the governor is a speed-proportional hydraulic pressure regulator, that moves the piston in or out (via force-balance against unregulated pressure) to adjust pitch. For me (as a long-lapsed mechanical engineer) that's sufficient to "unlock" the rest of the workings.
Douglas Bader crashed a Spitfire attempting to take off in coarse pitch at some point between March & May 1940, prior to the adoption of constant pitch units. It was in late June 1940 that de Havilland began fitting conversion kits to all Spitfires & Hurricanes then using adjustable pitch propellers & this work was completed by mid August, before the greatest air battles.
The constant speed props seem to function very similarly to modern variable valve timing sprockets in car engines. Controlled by oil pressure, although in cars, they're actuated with solenoids rather than springs.
Just to say there were 3 main brands of propellers in France: Eclair created along pattents of Marcel Bloch-Dassault and equiping e.g. most Spads during WW1. In the 30s and 40s Chauvière and Ratier were mounted on military airplanes. Ratier still exists in Figeac (south of France) in 2022 and makes the composite blades for the A400M and others.
It’s amazing how marine constant speed variable pitch props and air variable pitch constant speed props operate so well but in the complete opposite environments..
Very good points at 14:00 - re the adaption of constant speed props on the Spitfire MkI. Although the Rotol constant speed props were standard on production lines by early 1940, it wasn’t until after the Battle for France that existing front line fighters were retrofitted. The Luftwaffe’s comparison between the new 109E and a captured spitfire in June 1940 were conducted with a De Haviland ‘two speed’ prop running 87 octane fuel: the Germans believed their plane would have a slight performance edge in the up coming BoB, but were surprised by the performance of Rotol constant speed prop spitfires using 100 Octane fuel - which both the spitfire and Hurricane were using by July. The BoB Spit could climb 750ft a minute faster than the one the Germans tested only the month before. Ouch.
… the performance of De Havilland constant speed (upgraded) propellers using 100 octane fuel ! The Rotol constant speed props were on the new Mk IIs, only 4 squadrons had Mk IIs in early October 1940. The Bf 109 got constant speed props in the F model. Early installations in trial Es and early Fs had the constant speed controls wired off because of initial teething problem unreliability.
Mitsubishi A6 Zero was also using a Hamilton system for its adjustable propeller. The license for the Hamilton system was officially sold to the Japanese before WWII.
I remember from the book " the 1st team " that at the start of WW2 the prop control failed on wildcats. They would get down the deck and fly into the water just in front of the CV. Some pilots were able to swim to the side. Some
You got me following the channel at aerodynamics for naval aviators. My text book cal poly Pomona aerospace engineering 1970 to 1974. I met the author years later. Still have my copy
The only reason I didn't have to pause and replay sections of this video was because a few years back I was working @ GA Tech and in one their bookstores I found 2 books on aircraft maintenance, which had a surprising amount of information on piston driven aircraft from this era. I've got to find those books in storage. There are even schematic diagrams of the cables and pulley systems controling flight surfaces and such.
I crashed my first quad into a tree after 15 minutes. So I do find it amazing that they flew for 5 years, including learning to fly, without a fatal crash.
30:50 I think this is similar to the governor in a steam engine. Though, for the steam engine, it also has large metal balls at the end as counterweight to the centrifugal force. This is where the "balls to the walls" expressions comes from since making the engine faster means allowing the metal balls to come closer to the walls enclosing the engine.
Nope, balls to the wall comes from US pilots in WW2, the control levers for the engine on most US aircraft had balls on the top of them, going for max speed meant pushing them all the way towards the firewall, hence "balls to the wall". Another saying that comes from US aircrews during the war was "The whole 9 yards", a compliment of .50 cal ammo for either some fighter aircraft or some gunners in bombers (I've read sources citing both) was 9 yards long, if someone completely unloaded on something they would say "I gave him the whole 9 yards".
"One a day in Tampa Bay." My uncle flew the B-26, ultimately taken out by an 88 over Normandy during the first (and last) night mission flown by Marauders. (They lost 11 out of 30 planes during the mission with another 7 or so being written off after landing. The Brits were a bit late with their nightly mission so the German night fighters had nothing better to do. Plus radar-aimed 88a.) There is a narrative by his co-pilot that notes two failures of an electrically-controlled pitch control, one while my uncle was flying and one while the co-pilot was flying with the navigator in the right seat. I guess they got them sorted out by the time the plane was functionally operational.
Their best normal night fighter was the Ju 88, it could carry the heavy crude German radar and extra crew better than a Bf 110. 88 was a big number for nazi Germany.
Trivia, but Douglas Bader of RAF fame, crashed a Spitfire on take-off. He had forgotten to switch the propeller pitch from coarse to fine, and the aircraft careened down the runway at 80 mph, ultimately crashing.
Good for a last second pre-take off glance. Not a great mindset though if you are constantly alert for an engine failure, that is the prime requirement for safe multi engine flying. Getting the prop feathered as soon as you have correctly identified the dead engine involves pulling the blue lever right to the bottom without delay. For normal power reduction throttle is reduced _first,_ for normal power increase prop is increased _first._
@@givenfirstnamefamilyfirstn3935 Prop stays on top means exactly what you just described. Prop moves first when increasing power, moves last when reducing power, hence the expression "prop stays on top." It has nothing to do with a "last second pre-takeoff glance."
@@jaym8027 I hadn’t heard it. It makes sense if your Jack Ridley stand-in explains it. The first adjustment you make is a power reduction. The blues start off fully forward.
Douglas Bader crashed a Hurricane while attempting to take off with his propeller pitch set incorrectly the day before he was promoted to (I think) Wing Commander. It was an early Hurricane with what I am assuming was a two speed/dual pitch propeller, based on the what I gleaned from the events described in the book 'Reach for the Sky'. The book described a knob which was pulled out/pushed in (much like a choke in older cars) for fine/coarse settings. (Only fine and coarse were described, still, could have been variable pitch).
A perfect example of what simplifying/lowering operator workload is actually safer and how those "creature comforts" pay for themselves. My dad talks about how when Caterpillar introduced the floating gooseneck and suspended seat to their earth movers it added a significant portion to the list price. Most companies were reluctant to spend that money but the companies that did were getting more dirt moved per hour (which if you didn't know is how the company gets paid).
19 squadron Spitfire Mk I on 31st March 1940, it probably had the simplified two position prop control. He had been sent to 19 squardon to pick up some experience having just rejoined the RAF. The squadron had the wrecked Spitfire for a total of twenty days. He didn’t sound like a person who took standard (safe) procedures seriously.
Nice work Greg! Looking forward to the next in this series and the next aircraft you decide to look at, whichever one you decide to use (typhoon/tempest?)
1:49 This would explain, why many british and french fighters of ww1 are faster than german fighters, even though their overall design does not seem to be any faster.
I don't know if anybody has mentioned it already but your Stearman photo was a super Stearman with an R985 and a constant speed propeller. Normally they did have either fixed pitch or ground adjustable propellers.
Just as a wing can stall so too a propeller. Various pitch angels a huge advantage in propeller development. A speed regime of 0 to 500 mph yet relatively light weight. Every part of an aircraft is of great importance but none more so than propeller systems. Multiple engine aircraft up the ante with more complexity of numbers and pilot responsibilities.
- Greg's Airplanes = THE airplane history and technology guy!
- Forgotten Weapons = THE small arms history and design guy
- Chieftain's Hatch = THE tank guy
- Drachnifinal = THE naval history and technology guy.
There's many other really good people that cover these topics but those folks are the absolute master's in their fields for their technical knowledge, resource finding skills, presentation style, and ability to formulate the technical and historical information in a way that's easy to understand without being dumbed down.
Kudos!!!
Look up Mark Felton, 2 channels about mostly WWII, super interesting.
The Operations Room, honourable mention if you like a breakdown of battles or military events.
I agree with all, and watch every video, from all of them.
But about tanks, i would say The Tank Museum, with David Fletcher in particular, is my tank and military vehicle channel!
TIK is also a very very good historical channel, highly recommended!
Military aviation history is also good though you already stated there were many other good channels
Not to mention that these channels actually affect the way history is studied! Sinking of the hood was good as well as the Japanese attack thwarted by 2 small aircraft carriers... my personal favourite was in this channel when Greg proved that fighters DID have the range to escort bombers and the p51 story was spun so the public didn't string the bomber Mafia up by their thumbs
Greg, you consistently break down complex mechanical and engineering issue down to just the right level. Your explainations are spot on. Thanks for that.
"This is a simplified diagram. The actual diagram looks like the circulatory system of a small mammal .... which is to say its highly complex. But for our discussion..."
Must rate as the most eloquent word-picture *ever*.
Just poetry.
With a *very* sharp focus on the factual.
Excellent.
@@Farweasel 27:00
Learned alot about something I know f*€k all about & I wasn't bored. That's why I watch Greg's airplane videos.
As another fellow commented, 'I don't know anything about aerodynamics but feel really smart when watching Greg's videos'. Same for me.
Yup 👍
can relate
It's been nearly 40 years since I took my fundamentals of flight class in college so I've basically forgotten most of that stuff. Greg does a good job of explaining things.
I am a Registered Nurse and low time pilot. (No engineering background). Greg is a like some of the great professors that I had. He presents the information in such a manner that I often see the answer coming and before he makes the point. making me feel as if I solved it myself. Great job.
"What's dad doing?" "Oh, he's listening to a long video about propellers." ???????...
I have no idea how I stumbled on this channel, but it taught me more about the importance of engineering and math what 11 years of Russian school and college!
Greg has the talent to be a teacher! Best lectures ever!
Heh heh, prop failures may be rare now, but one almost happened to me! It was in a Rans S3 at my flight school with a carbon fibre prop. It was the oldest plane at the school with various miner gremlins and rattles and no-one liked that thing. The last two registration letters were Quebec Whisky and we called it “Quebec Fix-Me"!
I eventually heard it got totaled when one blade delaminated in flight, shortly after takeoff. They still had some thrust, so the instructor took over and made a 180 back to the runway. He very nearly pulled it off, and would have made it if there hadn't been a power line in the neighboring farm right at the edge of the field. (airfield owner had told me it was basically a spite wire. No comment) Instructor was okay, student got miner injuries (he went to a different school after that) but that airplane was a sculpture! I saw it a few days later and never have I seen a more bent airplane that wasn't in pieces.
The punchline came weeks later when I was bored in the office and happened to pick up the logbook for old Quebec Fix-Me. I looked down to the very last entry, and there was my name! I missed that ride by a few minutes worth of engine time!
Wow, I'm glad everyone was OK. Prop failures are very dangerous as you know. Rare, but very often fatal.
Are they supposed to be xrayed after an amount of hours? A friend had a prop from a cessna on his wall that looked fine, but apparently failed its xray test hence how he got it cheap.
Maybe thats just an australian law?
@@Colt45hatchback I don't think general aviation props get xrayed in service. He probably means that it failed an xray during manufacturing so it couldn't be sold as an airplane propeller in the first place.
@@TonboIV that makes sense, the paint was all intact, and i recall an alloy, or maybe stainless steel plate about 2-3mm thick and probably 3"x1.5" in size bolted to the outside of the centre of the prop between the blades and possible slightly toward the outer edge affixed with two large phillips head screws with something written/stamped in it, i cant remember if it was a date or if it said not for service or what. But i remember thinking that doesnt look like it would stay there with the engine vibration. So youre probably right it may have not passed qc inspection at the factory
Evidently the flight school was lax in it's maintenance because carbon fiber propellers require more maintenance than metal propellers, though that's true of all plastic propellers (carbon fiber is a variant of plastic)
Great stuff
My dad flew F4s, F4Us, F6s and others in WWII
His comments on the props, each had their own issues
The electrics would short out now and then and go into high pitch. The hydraulics would some times lose a seal and you’d get a oil spray on the windshield.
He crashed a F4 went the prop went into high pitch on takeoff.
Funny the story’s you remember.
I remember, as a child, in the mid-1950s being taken for a look-around in a local 'Old Curiosity Shop' in Watford. On the floor was a huge, four bladed wooden propellor with curved tips and transfers spelling 'Maurice Farman'. The price was £3.10/- (£3.50). That was probably my father's weekly wage at the time so it remained in the shop! I have never forgotten it and my child's eyes took in and retained all those details too.
Greg, as someone who went to A&P school in the 70's, took many a class on Hamilton Standard props, and had the opportunity to work on them, I have to say that you've posted an excellent explanation of the principles involved. The only problem with hydraulic props is that they are so reliable that many in the industry take them for granted. Bravo again my friend! You boil complicated subjects down so that the uninitiated can understand these complex systems. I've referred my apprentice to your videos as you explain these things very well.
So basically the magic of the speed regulator is a Watt regulator re-imagined, got it. This is hands down the best channel for people that love aviation and mechanical gizmos, so I challenge Greg to explain the mechanism for a constant speed contra-rotating propeller! Or the mast of the Ka-50/52 that I assume accomplishes the same function.
In a previous life I repaired and/or modified high performance props for racing and recreational boats.
To get the most out of props in any given application was a combination of math, theory, compromise and voodoo.
I found this video fascinating.
Thank you!
Thanks for the video. You finally made me look up the plant my Mom worked in. Frigidaire built propellers for multi-engine aircraft, but also built components for the Aeroproducts props.
Thanks Greg. I have used Controllable pitch propellers on Type 42 destroyers (Ships) which have a lot in common, although they are fully reversible and we did not run them at constant speed. Thy hydraulic systems you showed are familiar and I thought you did a great job of explaining them. Thanks for sharing.
Odd that you should mention this. My neighbor has ordered a variable-pitch marine prop from a company in the UK. He’s still waiting because it’s delayed in customs, but he showed me technical information that has a great deal in common with these aero props. I need to take a closer look.
The same sort of system was used in powers station and marine turbine power control. These run at constant speed but use the governors to move the steam throttle valves. They have built in positive feedback and control damping back to reduce oscillation and ultimately speed runaway. The issue with all of these systems is the potential for runaway where the governor goes into oscillation between full open and full closed. When that happens it’s the same effect as fully open. In a power governor you get max power runaway in a speed governor you get over speed.
“Screw”
I enjoy how Greg can make an esoteric topic such as prop pitch, and give us an exoteric explanation that makes it much more clear. Good job Greg, and looking forward to the next edition.
This is amazing. I had no idea that power was controlled by changing the pitch and throttle/ manifold. I thought the pitch was constant and only the throttle was used. I also didn't know why the p-47 had different nose cones. Now it all makes sense.
Just have to say, I sort of envy the man who first developed a mechanical governor like this (which I suspect might have been on a steam engine or even before that), and could observe his invention in action for the first time. Super elegant device in my eyes, simple and sooooo useful in every imaginable spinning machine!
Steam engines do have something similar. That governor is simple in principle, and brilliant in execution.
Pr-electronic automatic transmissions use a very similar governor on the output shaft.
Quite a few things have this type of governor. Old wind-up Victrolas to maintain turntable speed and single phase electric motors to disengage the startup windings to name two.
@@GregsAirplanesandAutomobiles en.wikipedia.org/wiki/Centrifugal_governor It seems governors of this type (in general layout at least) even pre-date steam engines!
@@GregsAirplanesandAutomobiles A steam engine governor uses exactly the same principle, and was undoubtedly the inspiration for this governor. This steam governor was invented by James Watt - in 1770!
Thank you once again for explaining something in a way that a non aviator, non pilot can understand. Now I get it. Love your work by the way.
Some very smart people back in the day figured all this engineering out, they were good.
They truly WERE the Greatest Generation, look at the generation that now is in charge
@@oceanhome2023 The Boomers
@@Mikshvert ~ They were pre-boomers.
All without computers too. These days, computers do everything.
I knew some of them
I'm so glad I have Patreon right now got gonna lie I'm very happy.
*not but Ik wym
Wow, that was everything *I'd never realised I wanted to know* about early-mid 19th century propeller pitch control!
I'm not even being facetious; I enjoyed that immensely, despite only having a passing interest in these subjects.
Thanks!
There were none in the 1800s.
@@givenfirstnamefamilyfirstn3935 yes yes very good you identified my typo. I did indeed mean *20th* century, obviously (I do understand how that naming convention works - although it is prime for encouraging such mistakes!)
@@brandonb3279 Hiram Maxim’s steam powered ‘flying machines’ did run in the late 1890s.
Greg- Thanks for this propeller series. It hits home for me personally as my father was "radio" on C-46 Curtis Commandos flying the "Hump" in late '44-'45. He had related this aircraft was sent to do its job way before it was perfected. The two most common problems being leaking hydraulics, and problematic Curtiss Electric props. It was my understanding if an engine was malfunctioning, many times the prop would not feather. Anyway, I am proof he made it through. Love your channel.
Both the Spitfire and Hurricane were fitted with constant-speed units in the field actually during the BOB. Engineers from De Havilland toured RAF bases teaching ground crews to fit them - if it's stupid but it works, it isn't stupid.
Yes. Greg mentioned that in the video. I recall a wild claim about a dozen years ago claiming German pilots were surprised by the performance of Spitfire in the B.o.B, saying it was the new 100 octane or something. However, I think you and Greg are correct- de Havilland engineers and mechs went around those bases and retrofitted constant speed/vari-pitch props on the a/c.
spitfiresite.com/2010/06/battle-of-britain-1940-constant-speed-propellers.html
@@orcstr8d I worked at HSDE on the Hatfield Airfield site for HSDE in the 1970/80's. One of the people I worked with was John Powell Williams a De Havilland Apprentice who in the 1940' went round the Airfields showing RAF Engine fitters how to it the Consant Speed Proppellors
@@derekambler Damn cool! Must have been something for those amazing mechanics 81 years ago this month.
I believe at the same time armoured windscreens were also retrofitted.
Sunday night: Watches Greg's video.
Monday: Impresses friends with knowledge about planes.
Greg's air planes: best aircraft encyclopedia ever.
From a Naval Aviator (P3 patrol) and Delta pilot, I always learn and enjoy your work, thank you.
Thanks. I fly with a lot of P3 guys. That sounds like some impressive flying down low over the Atlantic looking for subs.
Brilliant! Your videos are always a real treat.
Hi Greg, enjoy your presentations --- In 1954 I was stationed at Hickam field, territory of hawaii in USN squadron VR-7 -- our bird was the R7 v or super constellation -- This was one of the first applications of reversing propellers.
The prop was Ham std 43E 60 -- and was giving a bit of problems-- I worked in engine build-up and change but props were my responsibility -- In short, the internal spider support block were failing and we went through at least 4 modifications before a satisfactory solution was found. In two years I disassembled, modified, re-assembled and tested more props than the average mech would do in 20 years.
I think I could still take that prop apart today --
The governors were pretty trouble free, in operation they worked pretty much like a governor on a steam engine but with very precise tolerances ---
I will be watching this one a couple of times. Thanbks.
thank you for producing this....i have had a lot of questions about propellers for a long time
Great info on the workings of the constant speed prop. Re the metal prop blade thing, the Brits used a wooden composite called Jablo until the end of the war. I can't recall seeing them used other than on Spitfires, and not at all before the MkV in early 1941. You can see pics of Spit IXs crash landed in Normandy with their wooden prop blades shattered instead of bent. It's very distinctive. These were Rotol props (a company set up by Rolls Royce and Bristol).
IF U HAVE A PROP STRIKE WITH A WOODEN PROP, YOU PUT ON A NEW PROP.IF YOU HAVE A PROP STRIKE WITH A METAL PROP, THE ENGINE MUST BE TORN DOWN, AND THE CRANKSHAFT "RUN OUT" TO CHECK FOR TWIST.
Great video Greg, I think I understood this before but it's a good succinct explanation and I look forward to the next one.
This is gold.
My step-grandfather was RAF groundcrew in WWII. He said that early electrical controls for propeller pitch needed frequent pilot attention in climb or dive. The cause was change in resistance of wiring with temperature. This problem was solved later in the war by substituting a graphite conductor for a certain length of wire. The temperature coefficient of resistance of graphite is negative, while that for copper is positive; graphite and copper wiring could be connected in series so as to give the same resistance at any temperature.
Thank you for sharing this bit of insight!
The same thing can be achieved with with a copper nickel alloy like Constantan. (That is also used in thermocouples).
Excellent, this is bound to help with my Principles of Flight ATPL exam.
Good luck finding a *_flight planning_* UA-cam video. How do you get to Carnegie Hall? .......
Nicely done Greg. Cleared up a few things I had heard of but had never seen a thorough diagram of the system and the way they could be adjusted. Ingenious buggers back then.
Loving that Corsair mug!
Wish the Internet had been around when I did Commercial Pilot Ground School in 1982. This video would have been quite handy. Never flew anything with a Hamilton Standard CSU as everything I flew had the Mccauley CSU; basically same thing, different name. *Thanks Greg,* that video took me back a few years to happier times. Much appreciated. 👍 CAVOK and tail winds.
Thank you so much. Fantastic video Greg! This is a topic lots of us warbird geeks have always wondered about and have seen very little in the way of entry-level information about. Excellent video! Can’t wait for part 3 tomorrow.
Thanks for explaining these technical issues clearly.
I did some experiments with fixed pitch prop in dcs. I used P-47D-30 for this job, because obvious reason, curtis electric prop.
I tested couple pitch settings minimum pitch, climb pitch,cruise pitch. Take off with minimum pitch. I apply full throttle(i did not use turbo at all for all tests), first it looked fine but as i gained speed rpm pass 2750 red mark, i was forced to retard throttle, at moment when i lift off MP was 30inch. Top speed was 150-160 with small engine overspeed 2800rpm. Max MP below 25inch. Then i tested higher pitch settings, they improved flight top speed, but take off roll get ridiculous long, making impossible to take any combat load. Conclusion fixed pitch for P47 is not an option. I had so much fun testing that.
The Rhodesian Air Force used mark 22 Spitfires well after WW2. They stopped using them when shrinkage of the wooden prop blades due to the dry climate caused problems. Most model Spitfires seemed to have wooden blades, but some were fitted with metal blades in some theatres. I have a prop blade from a mark V and also a mark XVIII Spitfire….both wooden.
Looks like they got a "monkey model" version - far as I know UK mk.9 onwards at least had metal constant speed or metal variable pitch props. Mk22 with wooden props, someone got conned.
Excellent documentary style Greg , fascinating subject selection. Well done.
As usual a very interesting video! I knew quite well the difference between Hamilton Standard and Curtiss Electric propeller as well the Aeroproducts Propellers. All three companies produced lot of propellers during the 2nd WW and postwar. Generally speaking it was due to the efficiency of the propellers that permitted the airplanes to achieve their performance. A fascinating story indeed and thanks for doing a great job again 👍👍
Wonderful, as usual. Same applies to the Wright vid. You manage to be entertaining and thorough, a really rare combo of erudition and clarity. . Parece que hablas Espanol tambien. Hace dias estaba haciendo maromas en un Stearman equipado con 985, 2D30, sistemas por vuelo invertido y 4 ailerones. Pensaba en Ud en cada barril.
This guy needs more subscribers…exceptional knowledge!
Superb, Greg. A clear, fascinating and straightforward explanation of prop control. All new to me other than the names. I'm just coming up on my 3 score and 10 but new knowledge is just as exciting as when I was 7 rather than 70.
Thank you.
This stuff is so intriguing and I can't imagine where I'll ever use it. Still enjoy watching it.
Fascinating as usual ... thanks for boiling down all that data into a smooth intelligent presentation... with cool photos !
Another fascinating insight. Thank-you.
Thanks Greg Love Every Single Episode I Look Forward To Your Next 😀😊😊
I've been a flight instructor for 50 years and explaining a constant speed prop has never been easy. Some people will intuitively understand it, some won't. There's no substitute for actually flying a constant speed prop to understand how it's used.
Excellent video. Another mystery resolved!
Thank you, thank you thank you for doing your best to correct the common misunderstanding about Lindbergh's flight. I am _constantly_ correcting people on it.
You might be surprised to learn that the Battle of Britain included engagements over Wales, N. Ireland and even Scotland. So it would be correct to say the Battle of Britain was fought over Britain as opposed to England. I watched a DCS fight where a Sopwith Camel went against Fokker Dr.I over several rounds. It confirmed to me something I had read many years ago. The Dr.I got it's maneuverability more than anything else from it's fully floating rudder. You can see it here at 1:49 and compare it with the Albatros D.V at 2:17. where a fixed vertical stabilizer is visible with the rudder attached. I know it's a sim, so it can't be perfect, but Greg, you really should see that Dr.I flip around the sky. It's astonishing. It's called A Gentleman's Dogfight and it's by Growling Sidewinder.
Hi Greg! I need to offer some feedback from my time flying warbirds: Spit, Hurricane and Bf-109. I check out on the Brit aeroplanes first, and came to love their seemingly modern constant-speed props. Operating a Merlin is nearly carefree. The Bf-109 shocked me because it didn't have an operating C/S prop. In fact, it had an electrical prop control box on the floor, but consistent with its 1941 configuration, the restoration team lock-wired it OFF. In lieu of a "modern prop," there was a tiny propeller pitch toggle switch on the throttle, and a pitch indicator on the panel. What a mess! My warm-up routine in the RAF types started with a 1500 foot tall wingover from cruise power. Big speed changes resulted in big propeller pitch changes, but the pilot is blissfully unaware. In the 109, the airspeed changes caused the engine speed to bog down terribly, and it was barely able to achieve the maneuver. Manually regulating the prop pitch to control engine speed helped, but it was an "eye magnet" in the cockpit. I was appalled. I think that Luftwaffe pilots either (a) spent more time looking into the cockpit than ideal, (b) learned to roughly regulate the engine by sound, or (c) thrashed their poor engines when too busy to fuss with them. Maybe all of the above. Such differences are often overlooked, but the effect was not subtle. Great videos! Thanks!
Wow, thanks, that's a great post.
@@GregsAirplanesandAutomobiles Enjoying your work.
30.29 this is really simple well kindof. Greg you crack me up.
I k ow absolutely nothing about this subject but... I was having dinner with a good friend who told me that his brother made propellers for classic airplanes, it was what he did for a living. He mentioned that his brother had by some chance found the original specifications for a spitfire propelled in some old factory that was shutting down. I seem to remember being shown some press coverage on the phone. He also said that the propeller was not wood or metal but some composite laminate material. No idea what. I completely trust this chap and it was the first course so in fairly sure I understood. Might be worth looking into.
Some Spitfires used wood fibre and synthetic resin blades. I tapped a Mk IX prop blade a while back and it felt tacky like ‘araldite’ epoxy resin glue. The only replacements are manufactured in Germany. Allegedly (!) prop strikes are less traumatic as the blades abrade more with less shock loading than with a sudden shatter or bend.
Seems that we now have a UK company allowed to make propellers. en.m.wikipedia.org/wiki/Hordern-Richmond. Interesting. It’s a wood laminate called Hygdulignum. www.goodwood.com/estate/estate-news/blades-of-glory/
Good stuff, as always
Another of your videos that should count for WINGS credit. Well done!
I’m not sure I understand all the engineering nuances (I’m not an engineer or pilot), but this DOES explain why it might have been a minor miracle that my Dad’s F6F (Hamilton Standard prop) made it back to the USS Lexington in October, 1944 after a 20mm round from Japanese ground fire peeled away a good portion of the prop hub. He reported that the engine ran “rough but cool” on the (purposely) low-speed return trip, with oil pressure down to 10 lbs. by the time he landed. In the photo I have, the front of that big P&W behind the mangled hub was thoroughly covered in oil.
I think your Dad's incident reinforces the default position of a damaged pitch control should be in landing mode. My Dad had problems with Curtiss Elec. props flying the hump in C-46's. thanks for this good story.
The hydraulic constant speed reminds me of the 1-2 shift circuit of a Powerglide transmission.
I like to think of constant speed props as being like a cvt transmission for the air. Of course a lot of cars with cvts do it in steps which is ridiculous, but snowmobile transmissions harness the engines power in a very similar way. The engine can be tuned to make peak power at one specific rpm, and the cvt makes sure that the engine is always at that rpm when the throttle is wide open, except when nearing top speed of course.
I was told that the CVTs were made to shift in steps because it was felt that people would not trust a transmission that they could not feel shifting .
Great video Greg .....I always wondered how the constant speed prop worked. Just like you always do, you made it simple to understand. You are smarter than the average bear,
but you have a knack for dumbing things down to allow us average Joes to get it. Take Care Stay Healthy Jerry
Pretty much exactly the comment I would have typed. Thanks for saving me time.
As I understand it the Rotol prop which the British used quite widely in WWII was a wooden core with a plastic skin, where the leading edge was reinforced with a brass strip. I assume this was a wartime expediency but they seemed to work, considering they were used on the later Griffon Spitfires too.
This is essentially what MT propellers are today. These are high-end german made props that are used on a lot of modern GA aircraft as well as replica warbirds...
46 seconds and already 59 likes. Good work Greg.
Thanks, of course some of those likes were from earlier before it was public.
Hi. Very informative as always. I have just one correction? I believe the Wright crash was the result of the propeller shaft failing not the actual prop.
Olmsted's propellers were pretty unique... great untold story of early aviation. Check out the Olmsted-Pitts Pusher Airplane at the Smithsonian.
Thank you for the info overload! I always wanted to know how exactly aerodynamics for props and etc worked. I have Aspergers and appreciate the details. Again thank you
Another amazing Greg video!
wrt the Hamilton Standard prop, I think that the short summary is that the governor is a speed-proportional hydraulic pressure regulator, that moves the piston in or out (via force-balance against unregulated pressure) to adjust pitch. For me (as a long-lapsed mechanical engineer) that's sufficient to "unlock" the rest of the workings.
Douglas Bader crashed a Spitfire attempting to take off in coarse pitch at some point between March & May 1940, prior to the adoption of constant pitch units. It was in late June 1940 that de Havilland began fitting conversion kits to all Spitfires & Hurricanes then using adjustable pitch propellers & this work was completed by mid August, before the greatest air battles.
That dr1 fact wow I learned something new
The constant speed props seem to function very similarly to modern variable valve timing sprockets in car engines. Controlled by oil pressure, although in cars, they're actuated with solenoids rather than springs.
Just to say there were 3 main brands of propellers in France: Eclair created along pattents of Marcel Bloch-Dassault and equiping e.g. most Spads during WW1. In the 30s and 40s Chauvière and Ratier were mounted on military airplanes.
Ratier still exists in Figeac (south of France) in 2022 and makes the composite blades for the A400M and others.
Can I just say I love the fact that you used a picture of Fiery Ginger in this video.
It’s amazing how marine constant speed variable pitch props and air variable pitch constant speed props operate so well but in the complete opposite environments..
You’re the beat Greg! Another wonderful video
Very good points at 14:00 - re the adaption of constant speed props on the Spitfire MkI. Although the Rotol constant speed props were standard on production lines by early 1940, it wasn’t until after the Battle for France that existing front line fighters were retrofitted. The Luftwaffe’s comparison between the new 109E and a captured spitfire in June 1940 were conducted with a De Haviland ‘two speed’ prop running 87 octane fuel: the Germans believed their plane would have a slight performance edge in the up coming BoB, but were surprised by the performance of Rotol constant speed prop spitfires using 100 Octane fuel - which both the spitfire and Hurricane were using by July. The BoB Spit could climb 750ft a minute faster than the one the Germans tested only the month before. Ouch.
Thanks Andrew, well said.
… the performance of De Havilland constant speed (upgraded) propellers using 100 octane fuel ! The Rotol constant speed props were on the new Mk IIs, only 4 squadrons had Mk IIs in early October 1940.
The Bf 109 got constant speed props in the F model. Early installations in trial Es and early Fs had the constant speed controls wired off because of initial teething problem unreliability.
Another great explanation Greg!
Mitsubishi A6 Zero was also using a Hamilton system for its adjustable propeller.
The license for the Hamilton system was officially sold to the Japanese before WWII.
I remember from the book " the 1st team " that at the start of WW2 the prop control failed on wildcats. They would get down the deck and fly into the water just in front of the CV. Some pilots were able to swim to the side. Some
You got me following the channel at aerodynamics for naval aviators. My text book cal poly Pomona aerospace engineering 1970 to 1974. I met the author years later. Still have my copy
The only reason I didn't have to pause and replay sections of this video was because a few years back I was working @ GA Tech and in one their bookstores I found 2 books on aircraft maintenance, which had a surprising amount of information on piston driven aircraft from this era. I've got to find those books in storage. There are even schematic diagrams of the cables and pulley systems controling flight surfaces and such.
I crashed my first quad into a tree after 15 minutes. So I do find it amazing that they flew for 5 years, including learning to fly, without a fatal crash.
In fairness you also didn't crash fatally, and the Wrights definitely crashed planes before their first fatal crash!
30:50 I think this is similar to the governor in a steam engine. Though, for the steam engine, it also has large metal balls at the end as counterweight to the centrifugal force. This is where the "balls to the walls" expressions comes from since making the engine faster means allowing the metal balls to come closer to the walls enclosing the engine.
That's correct, it is similar.
Similar to an CAV DPA rotary distributor type diesel pump governor, cage and weights
Nope, balls to the wall comes from US pilots in WW2, the control levers for the engine on most US aircraft had balls on the top of them, going for max speed meant pushing them all the way towards the firewall, hence "balls to the wall".
Another saying that comes from US aircrews during the war was "The whole 9 yards", a compliment of .50 cal ammo for either some fighter aircraft or some gunners in bombers (I've read sources citing both) was 9 yards long, if someone completely unloaded on something they would say "I gave him the whole 9 yards".
"One a day in Tampa Bay." My uncle flew the B-26, ultimately taken out by an 88 over Normandy during the first (and last) night mission flown by Marauders. (They lost 11 out of 30 planes during the mission with another 7 or so being written off after landing. The Brits were a bit late with their nightly mission so the German night fighters had nothing better to do. Plus radar-aimed 88a.)
There is a narrative by his co-pilot that notes two failures of an electrically-controlled pitch control, one while my uncle was flying and one while the co-pilot was flying with the navigator in the right seat. I guess they got them sorted out by the time the plane was functionally operational.
Their best normal night fighter was the Ju 88, it could carry the heavy crude German radar and extra crew better than a Bf 110. 88 was a big number for nazi Germany.
thanks I wondered about this very subject for a long time !
Amazing video has always
fantastic video, Thank You Greg.
Trivia, but Douglas Bader of RAF fame, crashed a Spitfire on take-off. He had forgotten to switch the propeller pitch from coarse to fine, and the aircraft careened down the runway at 80 mph, ultimately crashing.
Thank you again, Greg! Your videos are the best!
love your videos. you should do a series on the advancements made during the Schneider Trophy and other early air racing.
Prop stays on Top is the mnemonic I learned for order of operations of a constant speed prop.
Good for a last second pre-take off glance.
Not a great mindset though if you are constantly alert for an engine failure, that is the prime requirement for safe multi engine flying. Getting the prop feathered as soon as you have correctly identified the dead engine involves pulling the blue lever right to the bottom without delay.
For normal power reduction throttle is reduced _first,_ for normal power increase prop is increased _first._
@@givenfirstnamefamilyfirstn3935 Prop stays on top means exactly what you just described. Prop moves first when increasing power, moves last when reducing power, hence the expression "prop stays on top." It has nothing to do with a "last second pre-takeoff glance."
@@jaym8027 I hadn’t heard it. It makes sense if your Jack Ridley stand-in explains it.
The first adjustment you make is a power reduction. The blues start off fully forward.
Thank you very much for a very interesting video!
Douglas Bader crashed a Hurricane while attempting to take off with his propeller pitch set incorrectly the day before he was promoted to (I think) Wing Commander.
It was an early Hurricane with what I am assuming was a two speed/dual pitch propeller, based on the what I gleaned from the events described in the book 'Reach for the Sky'.
The book described a knob which was pulled out/pushed in (much like a choke in older cars) for fine/coarse settings. (Only fine and coarse were described, still, could have been variable pitch).
A perfect example of what simplifying/lowering operator workload is actually safer and how those "creature comforts" pay for themselves.
My dad talks about how when Caterpillar introduced the floating gooseneck and suspended seat to their earth movers it added a significant portion to the list price. Most companies were reluctant to spend that money but the companies that did were getting more dirt moved per hour (which if you didn't know is how the company gets paid).
19 squadron Spitfire Mk I on 31st March 1940, it probably had the simplified two position prop control. He had been sent to 19 squardon to pick up some experience having just rejoined the RAF. The squadron had the wrecked Spitfire for a total of twenty days.
He didn’t sound like a person who took standard (safe) procedures seriously.
@@givenfirstnamefamilyfirstn3935 ...
Thank you for the correction and clarification.
Cheers.
Never knew that the development of the propeller was as interesting as the development of the airplane itself.
Nice work Greg! Looking forward to the next in this series and the next aircraft you decide to look at, whichever one you decide to use (typhoon/tempest?)
Had several prop failures on P-3s and Electra's. The props were the most complex system on the plane and could and did kill many aircrew.
1:49 This would explain, why many british and french fighters of ww1 are faster than german fighters, even though their overall design does not seem to be any faster.
I don't know if anybody has mentioned it already but your Stearman photo was a super Stearman with an R985 and a constant speed propeller. Normally they did have either fixed pitch or ground adjustable propellers.
Yup, that's already been caught, but good observation.
Just as a wing can stall so too a propeller. Various pitch angels a huge advantage in propeller development. A speed regime of 0 to 500 mph yet relatively light weight. Every part of an aircraft is of great importance but none more so than propeller systems. Multiple engine aircraft up the ante with more complexity of numbers and pilot responsibilities.