Warbird Information Exchange

Hi, gents,

I'm new to the WIX forums, and tried to use the search format for my question. Either I'm entering parameters incorrectly, or no one has asked this question recently. It's pretty simple:

Did the B-17 (E-model is specific to my interest in this case) have boost (hydraulic or other power assist) for the flight controls? For your interest, here is the scenario that I'm interested in.

On June 16, 1943, the B-17E flown by Capt. Jay Zeamer was damaged in a series of frontal attacks over Bougainville. Zeamer was badly wounded in both arms and legs, and the oxygen system was destroyed. He therefore put the bomber into a steep dive. Thanks to my colleague Rick Dunn, I got my hands on an Air Information Bulletin containing a detailed extract of the crew reports submitted that day--PRIMARY SOURCE MATERIAL. The extract describes the rate of descent as 6,000 feet per minute, which is actually PEGGED, so it could have been greater! Meanwhile, the copilot, Lt. John T. Britton, was unconscious with a head wound, so Zeamer pulled the bomber--which could have still been in the neighborhood of 45,000 pounds--out of that steep dive single-handedly. Since I'm not familiar with the flight controls, I don't want to speculate as to whether there was a boost system. If there was none, then his effort in leveling the aircraft off at 6,000 (the altimeter had been smashed, by the way) is all the more heroic.

I'm sure that many of you are familiar with the Zeamer/Sarnoski Medal of Honor situation. I will be describing it somewhat differently from the popular accounts in a new book due out in the fall.

Thanks in advance,

Bruce Gamble

Welcome to WIX Bruce!
I'm not sure about boosted controls on the B-17's, but I'm sure someone here will be able to help...and fairly quickly! I've always been interested in this particular incident in history and have had the good fortune and honor to have had dinner with Jay Zeamer back in 1989. Can't wait to see the final product.

Blue skies,
Jerry

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"Always remember that, when you enter the ocean or the forest, you are no longer at the top of the food chain."

B-17's do not have boosted flight controls. You kind of throw the wheel over and wait for it to turn.

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If God had wanted man to fly behind a flat motor, Pratt Whitney would've built one.

Thanks--but your answer would apply to the ailerons. What about the elevator and rudder controls? My guess is that they were cable-connected only, with pulley systems that would reduce that actual forces required, but no "boost."

My main point is that if there is no elevator boost, then pulling out of a very steep dive without the assistance of the copilot would be a real feat, especially for a badly-wounded pilot.

BG

No Boost, just cables.

Might be able to use the auto pilot to help, I've never seen one on a flying B-17, just in pictures.

Not sure if a Pacific "E" would even have the autopilot.

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Best Regards;
Chuck Giese --- Volunteer helping to restore B-17G 44-85734 "Liberty Belle".

I recall reading someplace (maybe in Jablonskis B-17 book) a copy of a page from the pilots manual stating something like 'maximum dive speeds without elevator modification restricted to 248 MPH' and as SKMSTR 02 says turn, count '1-2' and return to neutral, all the controls are powered by 'Norwegian Steam' but adrenaline is an excellent force multiplier

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Don't make me go get my flying monkeys-

Thanks for the help. I have made a slight correction, in that the air bulletin extract makes no mention of Britton (copilot) being wounded, therefore he would have helped with that "Norwegian Steam" effort in pulling the aircraft out of its maximum-rate dive. No matter, it must have been one hell of a descent!

BG

I believe co-pilot Britton was one of the few crewmembers who were NOT wounded on this mission, Bruce.

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Dave

man, I'm surprised the outter wing panels stayed on the ship

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Kind Regards,
Gary Lewis
J.A.F.O.

yep... there are ALOT of myths perpetuated by time and a lack of experience...The B-17 is as honest as the day is long...unless you really screw up and get into a spin you can fly it with one hand...I don't care what speed you are at.

JH

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www.spiritof44.com

The B-17E when equipped with the Norden bombsight had an auto pilot. It was called the AFCE for automatic flight control equipment. This was the predecessor to the C-1 autopilot made by Honeywell.

If the B-17 was equipped with the Sperry S-1 sight it would have had the A-5 autopilot.

Both of these autopilots had clutches in the cable drums. The servos were set up to slip at a predetermined torque. This was so you could overpower the servos should there be problems.

Although the autopilot was used on several occasions to fly the aircraft when the primary flight control cables were severed in combat, I doubt they would have been used to pull out of a dive. I would think that the clutches would slip at such high loads.

Besides the autopilot the B-17 series didn't have any other boost in the controls besides the Armstrong assist as mentioned above. Just cables, pulleys, bell cranks and leverage.

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To donate to the PV-2D project via PayPal click here http://www.twinbeech.com/84062restoration.htm

We brought her from: to this in 3 months: Help us get her all the way back

All donations are tax deductible as the Stockton Field Aviation Museum is a 501c3 nonprofit organization. Tell a friend as the Harpoon needs all the help she can get.

Thank you!

Taigh Ramey
Vintage Aircraft, Stockton, California
http://www.twinbeech.com
'KEEP ‘EM FLYING…FOR HISTORY!'

Someone once told me that the B-17 autopilot actuated just the trim tabs to make small corrections, rather than moving the entire control surfaces. Was I being "BS'ed" or was he telling me correctly? Someone please tell me the truth.

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Dean Hemphill, K5DH
Port Charlotte, Florida

The majority of the B-17's used the C-1 autopilot which had three servos, one for each primary control surface. These servos connected directly to the main control cables that operated the ailerons, rudder and elevator. No trim servos or electric trim actuation was used in this system.

Trimming was accomplished manually in conjunction with the autopilot control panel. You would trim the aircraft with the normal trim controls so the autopilots "tell tale" lights were not on solidly in one direction or the other. The lights, two per control, would indicate when a clutch in the servo was being engaged in one direction or the other to move the controls. They were supposed to blink back and forth when set up properly.

I seem to recall that the Sperry A-5 autopilot had trim servos but I am not positive about that.

As a side note possibly the last operation of the C-1 autopilot was on the Movie Memphis Bell. I remember talking to Tallichet at Chino many years ago when he was prepping his B-17 to fly to England for the filming. He was installing a C-1 because he didn't want to hand fly the aircraft all the way across the pond. I always wondered if he finished the install and if he got it to work.

I have a new in the shipping crate C-1 that is slated for our AT-11 project someday. I am looking forward to getting it operational.

_________________
To donate to the PV-2D project via PayPal click here http://www.twinbeech.com/84062restoration.htm

We brought her from: to this in 3 months: Help us get her all the way back

All donations are tax deductible as the Stockton Field Aviation Museum is a 501c3 nonprofit organization. Tell a friend as the Harpoon needs all the help she can get.

Thank you!

Taigh Ramey
Vintage Aircraft, Stockton, California
http://www.twinbeech.com
'KEEP ‘EM FLYING…FOR HISTORY!'

I don't know if Tallichet ever installed an autopilot in the Movie Belle, but I can tell you that there is no sign of one installed currently. No control head and no servos......

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Rod Schneider
Ball Ground, Ga