“Then there was that time a jet aircraft shot itself down . . . .”
No, that’s not the beginning of a sea story, a “no sh!t” story, or a tall tale. At least once . . . it actually happened.
And the pilot – though injured in the resulting crash-landing – lived to tell about it. He also later flew again.
. . .
The time frame: mid-1950s. Supersonic flight wasn’t new, but aircraft actually capable of same were still fairly uncommon. Manufacturers were still gaining experience in dealing with supersonic flight issues.
Enter the Grumman F11F/F-11 Tiger.
The Grumman F11F Tiger was developed under the Navy’s pre-1962 numbering scheme; it was re-designated the F-11 under the 1962 Tri-Service numbering scheme. It was the Navy’s second supersonic jet aircraft (the F4D Skyray was the first); and it was fairly successful. A total of 200 were ordered by the Navy, and it was flown by the Blue Angels from 1957 to 1969.
It also was armed with 20mm cannon. And that – coupled with the fact that it was also Grumman’s first supersonic aircraft and the company was still learning about supersonic flight peculiarities – led to the aircraft gaining a unique place in US military aviation history.
How so? On 21 September 1956, a Grumman F11F Tiger became the first jet aircraft to shoot itself down.
. . .
Here’s what happened. On that date, Grumman test pilot Tom Attridge was flying a Grumman F11F Tiger – BuNo 138260 – off Long Island. He put the plane into a dive, and fired a 4-second burst (some sources say he fired two bursts) from the aircraft’s 20mm cannon.
He was at approximately 22,000 feet altitude when he fired. He then continued his dive; some sources say that he increased his dive angle and accelerated as well.
At an altitude of about 7,000 feet, Mr. Attridge got a rather nasty surprise. His windshield caved in, and his engine started losing power.
Attridge thought he’d struck a bird, and tried to nurse his damaged aircraft back to Grumman’s Long Island airfield. Unfortunately his engine soon quit altogether. Since the F11F was a single engine aircraft, this was truly “bad news”.
Attridge crash-landed the aircraft. He survived, but was injured and unable to fly for some time. However, he did eventually recover and return to flight status. (The aircraft did not; it was a total loss.)
. . .
What had happened? Well, as Attridge dove his aircraft was under power; some sources say he used his afterburners and increased his dive angle during the dive. His aircraft thus almost certainly picked up speed while in the dive.
However, his 20mm cannon rounds didn’t; due to air resistance, their speed continually decreased. And since they were fired at around 22,000 feet altitude and at an oblque angle, they had a rather long time of flight.
Bottom line: at some point after his firing run, the aircraft’s speed matched – then exceeded – the speed of the rounds he’d fired. And when that happens, it becomes possible for the two trajectories to intersect.
On 21 September 1956, those trajectories intersected at approximately 7,000 feet altitude off the coast of Long Island. Post-crash investigation showed that Attridge’s aircraft was hit by three of his own previously-fired 20mm rounds. One of those rounds was recovered from his engine and was determined to be the cause of its failure.
. . .
OK, that’s enough “odd aviation history” for today. Enjoy the WOT, everyone – and the weekend.
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Sources:
https://en.wikipedia.org/wiki/Grumman_F-11_Tiger
https://www.popularmechanics.com/military/aviation/a27967/the-fighter-plane-that-shot-itself-down/
