B-17 crashes due to confusing controls - any info?

[Reegor]

The Brits were a lot slower on the uptake - there was at least on Viscount ended up on its guts because the pilot grabbed the wrong lever, and they were behind his seat to make it worse.

Funny you should mention this. I have compared RAF and USAAF manuals, and the RAF did not like checklists! It's almost as if they felt their pilots were too good to need checklists. i
For example, the RAF versions of some US airplanes had re-written and considerably shortened manuals! Why did they go to so much trouble to provide LESS information? I don't know.

All WW2 aircraft had problems with poor control locations and ambiguities which caused accidents. The USAF and USN were not immune. For example, they did not standardize instrument locations until the 1950s. But my impression is that as you say, the RAF was worse. Certainly 1939 RAF aircraft were a mess. Douglas Bader, on his first combat takeoff, forgot to switch his prop pitch. As a result, he did not take off, and badly damaged his aircraft. And he was a Squadron Leader at the time. (I wrote a whole chapter on the RAF, although it needs work.)

 

[MiTasol]

Funny you should mention this. I have compared RAF and USAAF manuals, and the RAF did not like checklists! It's almost as if they felt their pilots were too good to need checklists. i
For example, the RAF versions of some US airplanes had re-written and considerably shortened manuals! Why did they go to so much trouble to provide LESS information? I don't know.

All WW2 aircraft had problems with poor control locations and ambiguities which caused accidents. The USAF and USN were not immune. For example, they did not standardize instrument locations until the 1950s. But my impression is that as you say, the RAF was worse. Certainly 1939 RAF aircraft were a mess. Douglas Bader, on his first combat takeoff, forgot to switch his prop pitch. As a result, he did not take off, and badly damaged his aircraft. And he was a Squadron Leader at the time. (I wrote a whole chapter on the RAF, although it needs work.)

It is funny that the Brits had the basic 6 flight instruments layout locked down well before 1939 which as you say is far better than the US on that matter but from almost every other angle the US was ahead. The US fighter or trainer pilot (and many other aircraft pilots) from the late thirties on never had to take their right hand off the control column during take-off/climb or approach/landing but the Spitfire and Hurricane pilot was continuously changing hands because the throttle/mixture/prop were on the left and landing-gear/flaps controls on the right. The Americans had the engine cut-off built into the mixture control and the Brits had it separate and all over the place.
My pet hate though was the TBM's canopy. All the other single pilot US aircraft I had the pleasure to handle had a one piece canopy. The TBF/TBM canopy is two pieces split down the middle by a heavy structural rail. The number of times I hit my head on that !@#$%^ rail is beyond counting

 

[technique72]

Here's what was used when:

All B-17 airplanes 43-37874 and on used the pictured assembly for the central control panel.

All B-17 airplanes from 41-24340 to 43-37874 also used the same assembly, with minor changes, such as nutplates and nuts changing type.

Now, looking at just the Guard Assy. Landing Gear Switch (that's the official name of the spring loaded flap), it was used on all airplanes 41-2393 and on. That means it was used on all B-17E, all B-17F, and all B-17G. In fact, the drawing sheet is also used for the XB-29, and the B-29. You'll also notice that in the margins are drawing numbers for the YB-17, the XB-15, the 299, the B-17D, the B-17B, and the B-17C. I'm not sure why these are in the margins, but my guess is that those drawings reference this one, possibly in retrospect but I can't be sure. Those drawings aren't in the microfilm. You'll notice B-17G isn't shown on the drawing, but that's because nearing the end of development, sub-drawings were no longer always updated with the master, to save time by not doing non-essential work, as I understand it.

What this all means, is that the B-17E all the way through the G had the gear safety guard new from the factory, and it's likely that all earlier models were upgraded to include it as well if they were ever brought in.

View attachment 505034 View attachment 505035

Thank you for this research. This is great stuff. Where do you get these plans from?

So did these modifications by Chapansis only happen for a short time before the B-17E and before the spring release modifications?

In quote that is taken from Chapanis' autobiography, it says that(attahced)

 

[Eli Josephs]

Thank you for this research. This is great stuff. Where do you get these plans from?

So did these modifications by Chapansis only happen for a short time before the B-17E and before the spring release modifications?

In quote that is taken from Chapanis' autobiography, it says that(attahced)

The easiest and cheapest way to get access to the microfilm is through a subscription to Air Corps Library: Classic Aircraft Blueprints, Drawings & Manuals | AirCorps Library They are a great resource, but their archives are incomplete. Despite this, their microfilm scans are some of the best quality you'll find.

From what that article says, I'd say that it is partially, or mostly, made up. I'm no expert on the P-47 or B-25, but I'm doing a little quick research.

Very quickly, I can say that this is very unlikely in a P-47. The flap and gear levers move on two separate planes, 90 degrees to each other. Flaps are actuated by moving a lever forward, and gear is operated by moving a lever sideways. Not only do they move in two completely different directions, they would feel very different as well. The gear lever has a large ball on the end, while flaps is a small cylinder. Of course this may just be a later model, but since it's first test flight was in 1941 and it stopped production in 1945, I have my doubts about gear and flaps ever being confused, especially in 1943 (although it IS possible). Additionally, the P-47's gear doesn't retract directly upwards, it swings in. While on the ground, the gear leg is at a slight outward angle, to prevent being pushed back in and retracting accidentally. I don't know if this would prevent a gear retract or not, but it seems harder to do from a mechanical standpoint.

As for the B-25, it seems to be the most likely, if only, candidate for messing up the two controls in 1943. The levers are both on the center console, right next to each other. THe gear lever is lower than the flaps lever, so it's less likely to make the mistake, but it could happen. See image.

My conclusion, is that by 1943, none of the B-17s had had this problem for over two years, and the earlier built aircraft were likely already out of combat and been rebuilt or sent to a training field. If the P-47s ever had the problem, it probably wouldn't be present in 1943. The B-25 likely did have these issues.

It would seem that the article is bending the truth a little bit to make a point about Chapanis, or at the very least greatly over exaggerating and omitting information. I've personally come to that conclusion because of the date given and my knowledge of the B-17's design... By then, only two year + outdated airplanes would have the issue, and those planes wouldn't be in combat anymore, whereas the article makes it sound like all of the type had the issue, and it was still a current flaw happening all the time. For older aircraft used for training, with an inexperienced pilot, the accident rate is going to up, no matter the design of the aircraft.

I'm sure this led to the standardization of the shapes, but I don't think that they were used much during the war. On surviving B-25s, although I've only been in a few, I've never seen different shaped knobs on those two levers, which would indicate that they weren't changed. There's no reason to change the knob shapes back, if they are wartime. I have some doubts about making a widespread modification that required rubber, as well. Especially in England where most of the modification would be needed, rubber was in short supply, because it was needed urgently for tires, tanks, hoses, and airplane fuel tanks. Painted or even plain wood is a better and more realistic alternative. The article never mentions how many aircraft, or which types, were modified and when. I'd guess one or two were modified, and after the war it was pushed to standardize.

 

[technique72]

Thanks Eli, this is really interesting research and a little disconcerting to think that there might be truth bending to serve a myth. I came in here originally to get a little more info on a story that I have heard many times, even in the bestselling book Black Box Thinking.

Your analysis feels solid, and even the small details about rubber being in short supply makes sense.

It is strange when you face a story that might be exaggerated or just plain wrong, but repeated again and again with many copy errors.

I will try to get nearer the source of the information and see what if any archive data there is in the U.S. Army Aeromedical Research Laboratory archive.

 

[Eli Josephs]

Thanks Eli, this is really interesting research and a little disconcerting to think that there might be truth bending to serve a myth. I came in here originally to get a little more info on a story that I have heard many times, even in the bestselling book Black Box Thinking.

Your analysis feels solid, and even the small details about rubber being in short supply makes sense.

It is strange when you face a story that might be exaggerated or just plain wrong, but repeated again and again with many copy errors.

I will try to get nearer the source of the information and see what if any archive data there is in the U.S. Army Aeromedical Research Laboratory archive.

Keep in mind that I can only really speak for the B-17, and it can be hard to determine the specifics that are referenced. Sometimes books and articles never lie, but they are intentionally vague or simply don't have all the info themselves. My research into the P-47 and B-25 was very quick, if you dig more you might find differences between models throughout production.

The article you referenced might also be a little bit confused if it's an autobiography written later in life. The author may have forgotten details and exact dates. I know I can forget some details of what I did only 5 years ago, even if the big idea sticks around.

 

[Big Jake]

Hi everyone

I am new on here.

I am doing some research on the history of the gear and flap controls.

More specifically the incidents of crashes due to pilot confusing the gear and flap controls during landing in B17s.

In 1942, Alphonso Chapanis interviewed pilots who had survived the crashes in these B-17. After weeks of interviews he returned to the cockpit of the plane. He discovered that due to the proximity and similar shape of the landing gear and wing flap levers, a tired pilot thinking he was controlling the wing flaps to control speed, would accidentally retract the plane's wheels on landing, causing obvious catastrophe.

Due to this research, the Air Force attached wheel-shaped knobs to the landing gear control and wedge-shaped knobs to the wing flap controls so they wouldn't get confused.

I am wondering do any of the experts on this forum know any more on this? Does anyone have photographs of these controls before and after modifications were made to them?

Any help would be great. Thanks

Attached is a picture of the pedestal in B-17G "Sentimental Journey" that I fly in. The layout is very similar to the one described in Eli Joseph's post above. The flaps and landing gear on the B-17 are controlled by switches. The flap switch is the far right one, guarded by the two side risers. (the flap indicator is above and to the right of it). The landing gear switch is the one to the left of the two light switches, located to the left of the flap switch. It is guarded by a mechanical guard (colored red) that need to be raised when operating the switch. Our normal procedure is for the pilot flying to call "gear up" (or down) or flaps "half", three quarters or full, as required. The pilot not flying will put his fingers on the called for switch, call "identifying flaps (or gear) switch" and wait. The pilot flying will look and say "verified" if indeed the pilot not flying fingers are on the right switch. Only then will the pilot not flying operate the switch as called for. As you can see, no wheel shape or flap shaped switches.
Just as a side story - many years ago I ran a project in which a military transport (French) was to be certified as a civilian one. One of the issues that I had to address was the requirement to replace the landing gear switch with one with a wheel on it. Had to have a switch modified to incorporate the wheel that I had to have specially machined to fit.
Hope it helps.

Hi everyone

I am new on here.

I am doing some research on the history of the gear and flap controls.

More specifically the incidents of crashes due to pilot confusing the gear and flap controls during landing in B17s.

In 1942, Alphonso Chapanis interviewed pilots who had survived the crashes in these B-17. After weeks of interviews he returned to the cockpit of the plane. He discovered that due to the proximity and similar shape of the landing gear and wing flap levers, a tired pilot thinking he was controlling the wing flaps to control speed, would accidentally retract the plane's wheels on landing, causing obvious catastrophe.

Due to this research, the Air Force attached wheel-shaped knobs to the landing gear control and wedge-shaped knobs to the wing flap controls so they wouldn't get confused.

I am wondering do any of the experts on this forum know any more on this? Does anyone have photographs of these controls before and after modifications were made to them?

Any help would be great. Thanks

 

[Currell]

Hi everyone

I am new on here.

I am doing some research on the history of the gear and flap controls.

More specifically the incidents of crashes due to pilot confusing the gear and flap controls during landing in B17s.

In 1942, Alphonso Chapanis interviewed pilots who had survived the crashes in these B-17. After weeks of interviews he returned to the cockpit of the plane. He discovered that due to the proximity and similar shape of the landing gear and wing flap levers, a tired pilot thinking he was controlling the wing flaps to control speed, would accidentally retract the plane's wheels on landing, causing obvious catastrophe.

Due to this research, the Air Force attached wheel-shaped knobs to the landing gear control and wedge-shaped knobs to the wing flap controls so they wouldn't get confused.

I am wondering do any of the experts on this forum know any more on this? Does anyone have photographs of these controls before and after modifications were made to them?

Any help would be great. Thanks

Hi everyone

I am new on here.

I am doing some research on the history of the gear and flap controls.

More specifically the incidents of crashes due to pilot confusing the gear and flap controls during landing in B17s.

In 1942, Alphonso Chapanis interviewed pilots who had survived the crashes in these B-17. After weeks of interviews he returned to the cockpit of the plane. He discovered that due to the proximity and similar shape of the landing gear and wing flap levers, a tired pilot thinking he was controlling the wing flaps to control speed, would accidentally retract the plane's wheels on landing, causing obvious catastrophe.

Due to this research, the Air Force attached wheel-shaped knobs to the landing gear control and wedge-shaped knobs to the wing flap controls so they wouldn't get confused.

I am wondering do any of the experts on this forum know any more on this? Does anyone have photographs of these controls before and after modifications were made to them?

Any help would be great. Thanks

Dr Chapanis (Johns Hopkins) was one of the founding fathers of The Human Factors Society. This was one of the early examples of using engineering psychology to good use. This example is a classic, and is discussed in Ernie McCormick's Human Factors text. Currell

 

[technique72]

Attached is a picture of the pedestal in B-17G "Sentimental Journey" that I fly in. The layout is very similar to the one described in Eli Joseph's post above. The flaps and landing gear on the B-17 are controlled by switches. The flap switch is the far right one, guarded by the two side risers. (the flap indicator is above and to the right of it). The landing gear switch is the one to the left of the two light switches, located to the left of the flap switch. It is guarded by a mechanical guard (colored red) that need to be raised when operating the switch. Our normal procedure is for the pilot flying to call "gear up" (or down) or flaps "half", three quarters or full, as required. The pilot not flying will put his fingers on the called for switch, call "identifying flaps (or gear) switch" and wait. The pilot flying will look and say "verified" if indeed the pilot not flying fingers are on the right switch. Only then will the pilot not flying operate the switch as called for. As you can see, no wheel shape or flap shaped switches.
Just as a side story - many years ago I ran a project in which a military transport (French) was to be certified as a civilian one. One of the issues that I had to address was the requirement to replace the landing gear switch with one with a wheel on it. Had to have a switch modified to incorporate the wheel that I had to have specially machined to fit.
Hope it helps.

View attachment 505167

Thanks Big Jake, these seem like the modifications I am looking for. Thanks for the photo.

 

[technique72]

Dr Chapanis (Johns Hopkins) was one of the founding fathers of The Human Factors Society. This was one of the early examples of using engineering psychology to good use. This example is a classic, and is discussed in Ernie McCormick's Human Factors text. Currell

Hi Currell. Thanks for the lead. Do you mean the example of gear and flap switches is referenced in this book?

 

[Brent]

By the way, this story as told by Atul Gawande and many others before him is only partly true. The accident happened as described, in late 1935. It destroyed the only Type 299. The B-17s did not begin flying until 1937. The earliest manual I know of for the B-17 was July 1937.

The first checklist was in 1935, for a Navy aircraft. (At least, this was the first official checklist in a flight manual. Presumably pilots wrote thing on scraps of paper before that, but I have not been able to find any examples.) By 1937, Navy checklists and manuals were more sophisticated than the first B-17 manual. So the Army and B-17s were late to this particular party. It does make for a good story, though.

Another historical footnote: The chief of the Luftwaffe was killed flying his own aircraft in a very similar way: he forgot to release his gust flaps! This was in 1935. I have written all this up for a book I'm working on, and an article "Who Really Invented the Checklist?"

It has been reported that the crash of the prototype B-17 (the Boeing 299) occurred because the exterior gust locks on the tail surfaces had not been removed prior to the taxi and approach to the runway. Naturally, taking off without being able to move the controls caused the crash seen in the photo earlier in this thread. That's why not only the checklist, but exercising the controls as part of that pre-takeoff checklist came into being.

 

[Currell]

Hi Currell. Thanks for the lead. Do you mean the example of gear and flap switches is referenced in this book?

Yes, the gear and flap switches. This is a classic example of early "knobs and dials" human factors engineering.

Another related problem would be: how to configure the control to sweep the wings back on a variable sweep wing, such as on an F-111. Typically, in a "go faster" situation, the throttle is moved forward. But the "natural" way to control a wing that you wish to increase the sweep would be to pull the control lever backward' i.e; "go faster". So one goes one way, the other, just the opposite. Maybe a problem for pilot error (or maybe not, but not ideal).

One possible solution would be to have a tiny set of wings, geared together at the center, that would actually "sweep back" as you move this lever back. The pilot could feel this in his hand.

On the WW 2 bomber ( I recall it as a B24, but it may have been a B-17), a solution was to put a miniature flap on the end of the flap control, and a wheel on the landing gear control. I don't know if this was actually implemented.

On a related note, and this was on a fixed sweep aircraft, baseball great Ted Williams almost crashed an F9F (don't recall if it was a Dash 6 or 9) because of throttle confusion. He wanted more thrust, got less, but quickly corrected.

Currell