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View Full Version : P-39/63 2 Doors Why?



Ciscobird
02-19-2009, 02:14 PM
Hiya, a first post in years for me.....

I have a question that has been nagging for a while... Perhaps some of you can help or at least offer a comedy relief...

If I'm correct that both versions, 39 and 63 have two doors similar to automobiles (one for each side, duh, just want to be clear), how come they require 2 if just one could suffice.

From a design and production standpoint, I think it's a waste of resource and structual integrity for a single-pilot aircraft to have a door on each side. Of course, it's a Bell-designed aircraft, Bell is known for their unorthodox designs but still, why?!?

Can anybody come up with a good explanation?

Thanks! Now I can sleep better!

P.S. My apologizes if this topic has already been discussed.

Choctaw111
02-19-2009, 02:29 PM
Someone will surely have a better explanation, but I believe that it was simply for the ease of the pilot getting in and out, never mind to the reduced visibility over the wings. Give me a difficult plane to get into any day, as long as I have great visibility.

jarink
02-19-2009, 05:44 PM
The other door is for left-handed pilots.

Woke_Up_Dead
02-19-2009, 05:56 PM
Car-doors: what else do you expect from a plane that was built around a gun manufactured by Oldsmobile? You're lucky the navigation lights don't blink whenever you're about to make a turn.

CzechTexan
02-19-2009, 06:06 PM
That's a very good question Ciscobird.
I never thought about eliminating one of the doors and I guess Bell didn't think about it either. I've read about pilots only using one of the doors anyway (I think it's the right-handed door) because something on the left side was in the way and made exiting there difficult.
My guess for your question is it's better to have two doors in case one gets jammed. Excellent topic.

ImMoreBetter
02-19-2009, 06:43 PM
Perhaps to aid in bailing out? Two doors means that much easier to find a way out.

At speed, car-like doors would be very difficult to open, so perhaps having a door on each side means that only one needs to be out of the slip stream to get it open.

P-39 pilots could jettison both doors, and effective get sucked out of the plane.

And another question is, why did they settle on a door design anyway? If they decided on a door design, why not have two?

R_Target
02-19-2009, 08:13 PM
Burning right wing would be a good reason to duck out the left door, and vice-versa.

M_Gunz
02-19-2009, 08:27 PM
If one gets stuck - or - in a spin the G's might trap you to one side, so much easier to exit in that direction
than fight to open a door against uneven spin, like when one wing is a mess ferinstance.

Aaron_GT
02-20-2009, 01:00 AM
Early Typhoons also had a car door arrangement but AFAIK only one door.

erco415
02-20-2009, 05:19 AM
'Cobra pilots used the right door for normal entry/exit, as the left door was more difficult to use- the throttle quadrant was in the way. (Not a problem, apparently, when emergency egressing!). Looking at the fuselage structure, it may well have been advantageous to have the same structure on both sides. If you look at construction pictures, the door frame is hella stout.

You could also roll down the windows!

Cheer!

vassilisukharev
02-20-2009, 07:48 AM
I think they mention something about 2 door design in this video..

http://video.google.ca/videopl...20942029633091&hl=en (http://video.google.ca/videoplay?docid=-4973497638554184738&q=source%3A003433420942029633091&hl=en)

Aaron_GT
02-20-2009, 10:23 AM
You could also roll down the windows!

And fly with one arm resting on the door? http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Bobbo_Tabor
02-20-2009, 03:05 PM
Makes you wonder if the doors added to the P-39s bad reputation in USAAF. It looked like a car and not a plane to car happy Americans so they didnít like it. Coming from a less mechanized society the Russians didnít have the same preconceptions about what a plane is supposed to look like so the Russians were more inclined to be happy with it.

Woke_Up_Dead
02-20-2009, 05:23 PM
Originally posted by Bobbo_Tabor:
Makes you wonder if the doors added to the P-39s bad reputation in USAAF. It looked like a car and not a plane to car happy Americans so they didnít like it. Coming from a less mechanized society the Russians didnít have the same preconceptions about what a plane is supposed to look like so the Russians were more inclined to be happy with it.

Right, the Americans were too stupid to tell it apart from a car, while the Soviets were too primitive to know what a car and plane are supposed to look like in the first place.

jarink
02-20-2009, 08:58 PM
Originally posted by ImMoreBetter:
And another question is, why did they settle on a door design anyway?

I remember reading somewhere that it had to do with the air scoop on top of the rear fuselage decking. The designers thought there could be problems with airflow around the 'pit being disrupted by opened windows plus the problems it might cause for emergency egress.

Col.BBQ
02-21-2009, 01:32 AM
Originally posted by ImMoreBetter:
P-39 pilots could jettison both doors, and effective get sucked out of the plane.

No, you can't. P-39 and -63 pilots are warned never to open both doors while in egress since your head can get out but your lower half will get sucked back in.

Freiwillige
02-21-2009, 02:43 AM
I have read that the doors were a nightmare to get open during flight since you had the wind trying to push them closed. Try driving your auto down the freeway at 120 MPH and open the door, you get an idea what they dealt with at speeds double or triple or worse quadruple that trying to get out.

M_Gunz
02-21-2009, 07:12 AM
Bailing out at 400+kph from any plane isn't a great idea. At 600+, is it even survivable?

CzechTexan
02-21-2009, 10:39 AM
Originally posted by Freiwillige:
I have read that the doors were a nightmare to get open during flight since you had the wind trying to push them closed. Try driving your auto down the freeway at 120 MPH and open the door, you get an idea what they dealt with at speeds double or triple or worse quadruple that trying to get out.

Weren't these doors jettisoned and just popped out when bailing out? Not like car doors that are forced to swing open.

Russian pilots feared bailing out of the P-39 because of the possibility of getting hit with the rear stabilizer which is level with the door. They often belly landed instead and the plane's durability allowed it to be quickly repaired and perhaps flown again the same day. (I got this from reading "Red Star Airacobra.")

R_Target had a good explanation above which I got a chuckle from.

Freiwillige
02-21-2009, 08:15 PM
I have never read of them being jettisonable.

I have read more than once of pilots literaly prying temselves out of the door that kept trying to shut on them.

berg417448
02-21-2009, 08:29 PM
Check this link:
http://www.richard-seaman.com/...ighlights/index.html (http://www.richard-seaman.com/Aircraft/AirShows/Holloman2005/Highlights/index.html)

Comment from that link:

"I had an opportunity to speak to its pilot on the day before the show, he was certainly no spring chicken, but very enthusiastic and he explained a few features of the aircraft, such as the mechanism which allowed the pilot to bail out by jettisoning the door, which normally opened forward, obviously a problem if youíre trying to get out in a 200 mile per hour slipstream!


another one:

"Upon having to exit his aircraft in the event of damage or power loss, the pilot simply jettisoned the doors via lever and rolled out a side and off the wing. If enough time was allotted, he could even make his way to the wings edge and make a controlled jump."

http://www.militaryfactory.com....asp?aircraft_id=140 (http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=140)



"We arrived at Howard at night after an all-day ride in the back of a truck. The following morning we checked in with the CO and then were introduced to the P-39. I squatted on the right wing of one P-39 while my instructor, a first lieutenant, explained a few things. He told me to take the cockpit so I donned my seat-pack chute and headed for the right-hand door. He grinned as I realized that I wasnít about to enter that tiny opening wearing a chute. He told me to first put the chute in the seat before entering. I asked him how a guy could bail out but he said that after Ďthe door was jettisoned and with adrenaline flowing, you would pop right out. I also saw that the left-hand door was almost blocked by the throttle quadrant, So, I just shut my mouth and followed orders as a good second john should."

http://www.aahs-online.org/BackIssues/v51n4.htm

Tully__
02-22-2009, 02:09 AM
Originally posted by Freiwillige:
I have never read of them being jettisonable.

I have read more than once of pilots literaly prying temselves out of the door that kept trying to shut on them.
Also see the video linked in the post by vassilisukharev about half way down page one. In that you can see the instructor demonstrate the jetissonable doors.