SHOULD the P39 have been able to handle the Zero? Was it training or performance?

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

Status
Not open for further replies.
Here's the best P-39 box art I have ever seen.
 

Attachments

  • AirfixP-39Q-300DPI-Crop-1.jpg
    AirfixP-39Q-300DPI-Crop-1.jpg
    1 MB · Views: 151
It is very nice artwork indeed but having the Airacobra pilots caught on the ground during an attack isn't the best way to convey a fighter plane's supposed prowess IMHO....
 
It is very nice artwork indeed but having the Airacobra pilots caught on the ground during an attack isn't the best way to convey a fighter plane's supposed prowess IMHO....

Perhaps not...but, then again, an aircraft getting caught on the ground has nothing to do with the performance of the aircraft and everything to do with the intelligence, early warning and C3 capabilities.
 
I agree. But to promote your favorite plane I'm pretty sure that you wouldn't pick an avatar with the Oscar shooting down the Buffalo, now would you? ;) Even though it happened on occasion, through no fault of the pilot or aircraft involved....
 
The original of my avatar actually has one Ki-43 being downed but at least 3 Buffalos being shot down...so it's pretty balanced. :)

I also accept that joe public in general wouldn't comprehend the niceties of air raid warning.
 
I get a bit suspicious when small changes in an aircraft make huge changes in performance.
I will even grant that the P-39N had 150-160hp more at the higher altitudes but the climb figures don't track well.

I will try to post the relevant figures later.
A big reason why the climb for the N is a lot better than older P-39s is the increase from 5 minutes to 15 minutes for military power rating. This happened mid '42 along with finally discarding the port backfire screens. This increase to 15 minutes apparently was for other engines too since this is reflected in the P-47 (R2800) tests.

With the 5 minute limit the engine power had to be reduced from 3000rpm (take off/military) to 2600rpm (max. continuous) after 5 minutes. Climb was a lot slower since HP was reduced. This is on all the charts of the P-38, P-39, P-40, P-47 and P-51 (Allison models). Once the limit was increased to 15 minutes the climb for all those planes was greatly improved above the 5 minute mark. If this was retroactive to the older engines (like WEP) then those P-39D, F, K, and L would have been greatly improved also.

Oddly the climb test was a straight climb from takeoff up to the service ceiling. Good for tests, but in actual practice if the pilot was at combat power (3000rpm) and during that 5 minutes had to climb he didn't reduce power to 2600rpm for the climb. So the tests actually understated climb after the first 5 minutes.
 
1943, sea level to 15000 ft: the best fighter?
POST #29
I posted this back in 1 October 2012. In the five and one half years (almost) I have
continued my research with the help of several others. I would like to point out that
range was not a big consideration in this post.
To answer the original question asked by P-39 expert...NO, in the Pacific theater
of Operation, the P-39 at no time could be considered to have 'handled' the Zero.
One of the A6M's greatest assets was its range, it could strike anywhere and at
any time. The P-39N with its internal fuel capacity allowing it a 360 ml. range just
was not enough to get the job completely done in the PTO.
All P-39s were faster than all Zeros by about 40mph at all altitudes. Climb on the older models was not as fast above 12000' on the test graphs, but at 3000rpm it climbed as fast at all altitudes. Due to circumstances the P-39 was used mostly in the defensive role in '42 at Moresby and Guadalcanal so range wasn't as big a consideration.

The P-38 is considered to have excellent range. It held 150gal/engine internal. The P-39 held 120. After deducting the Reserve (for T/O and climb to 5000') of 25gal for the P-38 and 16 gal for the P-39 the useable fuel for both planes was 125 for the P-38 and 104 for the P-39. 21 whole gallons. The P-38 had a 165 gallon drop tank/engine and the P-39 had drop tanks of 75gal, 110, 158 and 175gal available. Range could have been increased to P-38 levels if needed.
 
The 110 gallon tank was used initially in late 1943 on P-47C/D C/L but AFAIK never on the P-39. First used on P-51B in May 1944.

I'm unaware that Bell added a tank pressurization capability such as slaving off exhaust or instrument vacuum pump. Did Bell modify the P-39 so that they could carry ANY tank above 20K? Do you have any source documentation of either a mission flown with 110 gallon tank or any mission flown above 20K w/75 gallon combat tank?

Please point to your sources.
Edwards Park in his factual book "Angels Twenty" indicates use of the 110gal drop tank as standard. On a couple of interception missions at Moresby he talks of climbing to 24000' to intercept the Bettys and Zeros with his 110gal drop tank attached. Upon contact with the enemy they dropped their tanks and he says his P-39 felt "light as a feather, wonderfully agile and responsive. I would have loved to have flown it for a little while to enjoy it, but (his flight leader) was dropping his nose toward that (enemy) formation...". Why intercept incoming bombers with a drop tank? Seems odd, but virtually every mission was with drop tanks and the P-39s were loaded that way for those missions.

Park was actually there as a 2nd Leutenant pilot, so his experiences were actual fact. He wrote a second book, "Nanette" which covered the same material but was fiction and contained all of the outrageous stories he had heard about other pilots in NG. Quite funny and entertaining. Both books were a capsule of everyday life for those guys serving in NG and a fun read.
 
So what was the climb performance and air speed while climbing with 110 external tank?
 
Oddly the climb test was a straight climb from takeoff up to the service ceiling. Good for tests, but in actual practice if the pilot was at combat power (3000rpm) and during that 5 minutes had to climb he didn't reduce power to 2600rpm for the climb. So the tests actually understated climb after the first 5 minutes.

In actual Practice, the time to climb test was at maximum power available by the 'book' - and does not understate anything. That specific test was performed to get an idea what the airplane could be expected to do for the weight and balance conditions cited in the test.

The primary reason was to gauge interception capability and often flown in AAF 'Fighter Condition' of reduced fuel and ammo and no external stores.
 
Actually I read an article by a pilot who flew Spit V's in the Med. On his first flight just after takeoff he got intercepted by a P-39 and got "shot down" multiple times while he was trying to build up some airspeed.

Of course, if he had been flying a Clipped and Cropped Spitfire V it might have been a different story.

I love that P-39 artwork partially because it reminds me so much of a cover from a "Men's" magazine I saw in the 60's Very similar kind of a painting, a P-39 pilot opening the door and entering his airplane as enemy aircraft approach in the sky. Except that also scrambling into their Airacobras in the background were a bunch of beautiful scantily clad women.
 
A big reason why the climb for the N is a lot better than older P-39s is the increase from 5 minutes to 15 minutes for military power rating. This happened mid '42 along with finally discarding the port backfire screens. This increase to 15 minutes apparently was for other engines too since this is reflected in the P-47 (R2800) tests.

I can see how the time to altitude would be reduced by this, but peak rate of climb should be unchanged.
 
Status
Not open for further replies.

Users who are viewing this thread

Back