Form: 97 Data
Date: Wed, 31 May 2006 16:27:05 -0300
From: Don Ledger <dledger@NS.SYMPATICO.CA>
Subject:  Climbing Speed Not Same As Maximum Speed of F-51 (425 mph)
Cat: 11
Distribution: CE, SHG

Francis Ridge wrote:

At 01:01 PM 5/31/2006 -0300, Don wrote:
That's one I'd never heard before. As you say, hearsay, however. That portion of dialogue between the controllers and Mantell has never been mentioned, either to support that Mantell had the oxygen or that he did not. Frankly it has always bothered me that an experienced fighter pilot would ever climb past 12,000 feet [daytime flight] without oxygen. Excited he may have been about chasing the "object" but it would not compare with the various and heightened emotions that fighter pilots would experience when engaging an enemy.

That part has always bothered me, and you expressed it very well. I had said that Mantell had been in stressful situations in aerial combat, yet going after an unidentified object in broad daylight shouldn't have affected his mind enough to do something life threatening.

And while it was true that Mantell would have trouble reaching the balloon height (his 30,000 verses 50-100,000 ' for the balloon), the speed of the then one of the fastest airplanes we had of almost 450 mph would have overshot the higher object very quickly, not traveling faster or even "at half my speed".

Hi Fran,

Though the F-51 was capable of speeds in excess of 425 mph in straight and level flight under optimal conditions, it would have been a very rare day for it to reach 450 mph. Easy downhill mind you. In a climb it would have been struggling at its maximum climb angle of 17 degrees [the wing would stall over that angle even with engine laboring and blower at high readings in inches of manifold pressure] to get up to or over 200 mph. Even then it would have been probably mushing. The greater the altitude the less the rate-of-climb [ROC] versus forward speed.

This being January and the air cold, thick and stable he would have had some small advantage over Summer climb rates. If the "object" was above 31,0000 feet or below 28,500 [stretching the parameters of the JS] then it would have been out of any Jet Stream influence but "it" would have needed only a couple of dozen mph to outdistance him if it was already at altitude and traversing across the sky.

During the days of 1947 and 1948 the Air Forces were only just beginning to understand that there really was a jetstream up there. Bombers [B-29s and Lancasters] complained about it during the war and the Japanese suspected it [Fogo ballons] at least from their position to the west coast of North America.

But yes, the real puzzler was Mantell's disregard for anoxia. He knew better. I can't understand why he would have gotten so excited about this object, more excited than if he had been in combat, to ignore this obvious danger.

Don Ledger