Transonic Spitfires?
Congrats to Nicholas O’Dell on a great Spitfire article [“Mitchell’s Masterpiece,” November]. We need to be reminded now and again just how good this airplane was/is, and what an impact it had on the first half of the 20th century. We all know that it was a “just in time” creation whose performance staved off what could have been an even more disastrous time for Europe.
I have one small nit to pick: O’Dell contends that various Spitfires had been clocked performing spectacularly fast dives. The jaw-dropping 690 mph claim was the one that threw me right out of my comfort zone. It’s common knowledge that the Republic P-47 Thunderbolt was the all-time WWII dive champ. As Günther Rall once put it, “That thing must have had a big brick in it someplace.” Yet even the T-Bolt, which would fairly gallop away from any Spitfire in the vertical, managed “only” 550-560 mph in that regimen on a really good day.
But if the Spit in question really did hit 690 mph, and that worked out to .94 Mach as O’Dell states, then we have a serious problem. On a good FAA day (29.92 baro, 59 degrees) the speed of sound at sea level is 761 mph. It decreases with altitude until it reaches around 660 mph at 30,000 feet, give or take, where it levels off and remains up into the stratosphere. Therefore, the point at which 690 mph equals .94 Mach along that continuum is approximately 8,500 feet ASL, the altitude where the Spit would had to have been. So here we have a Spitfire in a vertical dive at 8,500 feet, booking it at 690 mph, with driver and mount about nine seconds shy of boring a smoking hole in the ground. Given the sink rate of the average WWII fighter when cranking out of a dive, at 690 mph it’s likely the plane would have reached straight and level flight and been on his way back up again at a point, oh, about 15,000 feet under the sod.
The reality is that any wind-driven airspeed indicator is notoriously inaccurate at speeds even approaching Mach 1. I once read an article crediting a P-39 with a “new dive record” of 720 mph! The P-39 was in fact probably nudging 500, while the Spitfire in question might have been closing in on 530 or so. To O’Dell’s credit, he does use the term “indicated” at one point, and I suppose that’s the escape clause in such claims. But the Spitfire was no Mach-buster.
Michael McCrath
West Seattle, Wash.
Military Twin Courier
Regarding your “Mystery Ship” answer in the November 2013 issue, the Helio Twin Courier (U-5) did appear in military markings [see photo above], as I found photos of it on the web, reportedly taken at Hurlburt Field, Fla. The aircraft is marked as 59-0336, but this may be a fake serial number. Also, I remember seeing these aircraft in use (I assume by the CIA) in Laos during my 1969-70 tour with the 21st Special Operations Squadron at Nakhon Phanom, Thailand. I saw one of them at a Lima Site in Laos.
Sr. MSgt. Jim Burns
U.S. Air Force (ret.)
Navarre, Fla.
Adversary Turned Friend
On June 6, 1944, over Romania, Lieutenant Ion Dobran [mentioned in “Ploesti: The Rest of the Story,” November] mutilated my P-51 Mustang and qualified me for a Purple Heart. His attack was from my rear, and I never saw the plane that shot me. Decades later, when I met and became friends with Honorary General Dobran, our efforts to talk were possible only because of interpreter Alex Carllson. Ion knew no English, and I knew no Romanian, so some facts may have been garbled or misunderstood, but I believe the following account is true.
During WWII, Dobran scored 10 victories over Russian, American and German aircraft—the latter after August 1944, when Romania switched to the Allies’ side. After the war’s end, the Soviets stripped him of his possessions, but he eked out a living working as a lathe operator. It would be nice to believe I were half the gentleman that this Romanian veteran of the “Big War” is.
Barrie Davis
Zebulon, N.C.
Immelmann or Lazy 8?
Regarding what constituted an Immelmann [“The Eagle of Lille,” November], I performed what we now call Immelmanns in my WWII U.S. Navy flight training. Much more recently, I had arranged for a 90-year-old ex-RFC/RAF pilot to ride in and maybe fly a Navion. A former Bristol Fighter pilot, he had been shot down and spent time as a POW. I was in the back seat when the owner turned over control to the old gentleman, and I was impressed with his smoothness. But I was taken aback when he announced that he was going to do an Immelmann!
What he did was a couple of wingovers. I think the Army would have called them Lazy 8s. I have heard that the Fokker Eindecker wouldn’t have had sufficient roll authority to do the other kind.
Bill Woodall
Akron, Ohio
Stuka Massacre
Your article about the Stuka and Hans-Ulrich Rudel [“Screaming Birds of Prey,” September] reminded me of an article in the Fall 2004 issue of the North American Aviation Retirees Bulletin by Captain Jim Brooks. On July 22, 1944, he led his 307th Fighter Squadron on a mission from Bari, Italy, to Mielec, Poland. On the return they encountered Rudel and his Stuka wing mauling a Russian column, and destroyed 27 Stukas before they had to break off due to critical fuel levels. Returning to base, the 307th had flown over 3,200 miles and destroyed more than 40 aircraft in the air and numerous enemy ground vehicles and personnel without losing a single pilot or P-51.
Ed Rusinek, Editor
North American Aviation Retirees Bulletin
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