Cause and Effect

Quit Hitting Yourself

Did you ever wonder to yourself, “If jet fighters can fly faster than a speeding bullet, and they shoot bullets, what’s to stop them from flying into their own bullets??” The answer may astound and amaze you! Not only is it possible to shoot yourself down, it has actually been done! Once seems to have been enough, and the military evolved its flying combat tactics so that it wouldn’t happen again.

In the fall of 1956, Grumman test pilot Thomas W. Attridge, took out an F11F ‘Tiger’ for some over water weapons testing. The 20-millimeter Colt cannons were mounted under and aft of the air intakes, and initially the spend shells, which were ejected overboard, were impacting the fuselage and leading edge of the horizontal stabilizer. To remedey this, the ejection chutes for the shells had been modified. Attridge was going to fly some high speed runs and fire the guns to test the changes.

As illustrated above, the flight profile called for the “pilot to start out at 22,000 feet and accelerate in afterburner at a 20 degree angle past Mach 1. Passing through 13,000 feet he would fire a four second burst of the cannon, wait three seconds to allow the guns to cool, and then fire a second burst, ending the profile at 7,000 feet when the ammunition load would be expended.” (aviationtrivia)

Attridge executed the profile, but after expending the ammuntion encountered an impact that shattered the armored glass of the wing screen. he quickly pulled up and turned back to the Grumman field in Calverton, New York, thinking he had hit a bird.

The performance of the plane continued to degrade, and the plane settled into the trees 3/4 of a mile from the runway, but the pilot was able to escape unharmed.

Examination of the aircraft showed it had been hit by at least three 20-millimeter rounds- one in the windshield, one in the right intake lip and one in the nose cone. In addition, projectile fragments were found in the first compressor stage of the engine along with fan blade damage- engineers suspected that perhaps the round that hit the right intake ricocheted into the engine. It was determined that Attridge had inadvertently shot himself down. At the first cannon burst, he was in 0.5G supersonic descent and had actually flown underneath the trajectory of the cannon projectiles from the first cannon burst. Eleven second later, as he began to pull out of the descent, he flew into the stream of projectiles from the first burst.

Subsequent examination of the aircraft showed that Attridge had flown the same test profile earlier that day and what was thought to be large ding from an ejected casing on the vertical fin actually turned out to be a projectile hit- apparently Attridge had grazed himself on the first test flight of the day and gotten away with not shooting himself down! (aviationtrivia)

20mm Round Pulled from Engine

Special thanks to P161911 for finding this gem for us, which those of you who saw the John Glenn Speed Record Shutdown may have already noted. It was too outlandish of a tale to leave languishing in the comments!

Images, in order of appearance are from wikipedia.orgmillionmonkeytheater.comcheck-six.comwikipedia.org, and check-six.com, with info from check-six.comaviationtrivia.blogspot.com, and aerofiles.com.

  • Apparently this is not uncommon, especially with new pilots, just usually without such catastrophic results with training ammo. The biggest problem is the bullets start slowing very shortly after leaving the barrel. The plane either remains at the same speed or accelerates.

  • highmileage_v1

    If he was a typical fighter jock Attridge would have put in for the "Kill". His boss probably would have laughed and then chewed him out.

  • Number_Six

    Woah, this is a good one! Thank you Featured Posts!

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