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The Feathered Threat To US Air Superiority
Hugh Pickens DOT Com writes "Mark Thompson writes in Time Magazine that Air Force pilots flying the T-38 Talon can rest easy, knowing that their cockpit canopy can survive hitting a 4-lb. bird at 190 mph. Unfortunately, the Northrop supersonic jet trainer has a top speed of 812 mph. 'To my knowledge, the training planes are the only ones in the Air Force fast enough to make a bird strike lethal, and with a windshield too flimsy to deflect one,' wrote one Air Force pilot. Midair collisions between birds and Air Force aircraft have destroyed 39 planes and killed 33 airmen since 1973. That's why the USAF is seeking comments to 'identify potential sources, materials, timeframe, and approximate costs to redesign, test, and produce 550 T-38 forward canopy transparencies to increase bird strike capability.' The move follows a T-38 crash on July 19 in Texas triggered by a canopy bird strike. 'The current 0.23 inch thick stretched acrylic transparency can resist a 4-pound bird impact at 165 knots which does not offer a capability to resist significant bird impacts, and has resulted in the loss of six (6) aircraft and two pilot fatalities,' the service acknowledged. 'Numerous attempts since 1970 were made to evaluate existing materials and redesign a transparency that could withstand a bird impact of 4 pounds at 400 knots.' Previous efforts have foundered because they'd require expensive cockpit modifications to the twin-engine, two-seat supersonic jet. 'Although it would increase the level of bird impact protection,' the Air Force said, 'the proposal was cancelled due to the high cost of the modification.'"
Transparent Aluminium
http://phys.org/news167925273.html
"Mark Thompson writes in Time Magazine that Air Force pilots flying the T-38 Talon can rest easy, knowing that their cockpit canopy can survive hitting a 1.8 kg bird at 300 km/h. Unfortunately, the Northrop supersonic jet trainer has a top speed of 1307 km/h. 'To my knowledge, the training planes are the only ones in the Air Force fast enough to make a bird strike lethal, and with a windshield too flimsy to deflect one,' wrote one Air Force pilot. Midair collisions between birds and Air Force aircraft have destroyed 39 planes and killed 33 airmen since 1973. That's why the USAF is seeking comments to 'identify potential sources, materials, timeframe, and approximate costs to redesign, test, and produce 550 T-38 forward canopy transparencies to increase bird strike capability.' The move follows a T-38 crash on July 19 in Texas triggered by a canopy bird strike. 'The current 5.8 mm thick stretched acrylic transparency can resist a 1.8 kg bird impact at 300 km/h which does not offer a capability to resist significant bird impacts, and has resulted in the loss of six (6) aircraft and two pilot fatalities,' the service acknowledged. 'Numerous attempts since 1970 were made to evaluate existing materials and redesign a transparency that could withstand a bird impact of 1.8 kg at 740 km/h.' Previous efforts have foundered because they'd require expensive cockpit modifications to the twin-engine, two-seat supersonic jet. 'Although it would increase the level of bird impact protection,' the Air Force said, 'the proposal was cancelled due to the high cost of the modification.'"
All the Talons are getting to the end of their service life, which means you either push them through a very costly life extension program, or you replace them.
All of the Talon replacements are off-the-shelf systems, with little to no custom development required, and all are proven platforms (with one already being in USN service) so the cost for replacement is likely to be very manageable.
So don't discount the fact that they are being replaced, its going to happen.
Most migrating birds fly at altitudes between 10,000 and 20,000 feet.
Nope.. Most migrating birds are flying UNDER 2,000 ft AGL which is where most bird strike incidents happen. There have been NO REPORTED strikes above 6,000 feet.
See the WikiPedia article on Bird Migration http://en.wikipedia.org/wiki/Bird_migration and look at the second to last paragraph in the "General Patterns" section.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
This is the T-38 trainer. It's not a combat aircraft. The T-38 is fast and modern looking, but the first flight was in 1961. Back then, one in five fighter pilots died in accidents, without any help from the enemy. In the 1950s and 1960s, fighter pilots were viewed as expendable. It's not a career choice for the timid.
The T-38 has killed many pilots. Good ones. Four astronauts, four of the USAF Thunderbirds. Yet fighter jocks like to fly it. It's not as bad as it used to be - the original engines were unreliable.
The ejection seat has saved many T-38 pilots. The T-38 ejection seat blasts through the canopy to get the pilot out. There's a big spike on top of the seat to punch through the canopy.Here's the 1990 redesign for a canopy that will resist bird strikes. "The seat mounted cutting blade is virtually ineffective in cutting through materials which comply with Bird collision resistance." So toughening up the canopy meant a new ejection system. Fighter planes, which have tougher canopies (they're expected to be shot at) have such systems, which usually involve explosives shattering or releasing the canopy. The T-38 is just a trainer - no armor.
The T-38 later got an ejection seat upgrade with zero-zero capability (you can eject while parked on the ground, which is useful if you have a fire during engine start or a bad landing), and that seems to have a new canopy disposal system. They had to give up the tiny bit of luggage storage the T-38 had. One of the original Mercury astronauts (they were issued T-38s as personal transportation) was able to find a case that would just fit the T-38's space under the seat. But for a few weeks, he wouldn't tell the other astronauts where he got it.