Posted on 11/28/2007 4:27:09 PM PST by Excuse_My_Bellicosity
November 27, 2007 (by Asif Shamim) - Air Force Times is reporting that an accident investigation board has concluded its investigation and released a report on Monday saying that F-16C (#91-0386) crashed due to a jammed throttle cable during a night training mission over the Nevada test range.
The pilot, Maj. David Epperson declared an in-flight emergency 46 minutes into his mission when he discovered the engine throttle was stuck at max settings for the engine. With the jet stuck with afterburners on, he realised he would be unable to make a landing at the Tonopah Test Range Airfield on March 12th.
On declaring the emergency a decision was made to let the F-16 from 16th Weapons Squadron run out of fuel. This took approximately 8 minutes for the tanks to run dry. The Major’s plan was then to glide the jet into land at Tonopah.
The problem was then further compounded when the airfield automated lights failed to activate when Epperson and his Flight leader radioed in the emergency.
The lights finally came on as the Major was on approach to the airfield. Realising he would not reach the runway and only 50 feet above the desert he decided to eject. Less than 2 seconds later the F-16 crashed 1,500 feet short of the runway skidding 1,000 feet before stopping.
The accident board determined that the cable which was first installed back in 1991 had passed recent inspections. Investigators could not be certain when or how the cable became damaged.
At the time of the incident, Epperson an experienced pilot was assigned as an instructor pilot with the Weapons School based at Nellis Air Force Base. He was also the also the chief of safety for the school.
Not as bad a you might think. They have a ram air turbine that pops out to power the control systems, both hydraulic and electronic components. It sounds like without the lights, he got a little too low too far from the runway threshold, with not enough energy (speed!) left to trade for altitude.
My throttle cable jammed wide open on my 1974 Porsche 914. The return spring snapped. I had to make a pretty quick decision as I couldn't shift and a fairly sharp turn was ahead. I just turned the ignition off, disengaged the clutch and applied the brake to a safe stop. I called for a tow truck to take the car the rest of the way home. About 3 miles. The truck didn't come for 3 1/2 hours. It wasn't a happy night. My wife was working the 3 PM to 11 PM shift, so I wasn't going to be rescued with a ride home.
8<)
A multi-stage afterburner?
I think maybe you need to expand the acronyms. Are you saying that the cable is or is not connected to the pilot's throttle control?
And I worked on the F-16 too, but the throttle wasn't part of what I simulated, in fact I faked the entire throttle and engine response, since it wasn't under the control of "my" system (The LANTIRN TF subsystem) anyway, although it probably should have been. That became an issue during the flight tests. They were testing the low speed end of the TF flight envelope, and got a little bit behind. Now I see, just now in fact, that the manual says not to hesitate to use the afterburner to maintain safe airspeed. In the flight test the guys. got way slow and where headed up a pretty big "hill" somewhere in Maine or thereabouts, and undershot the selected clearance by quite a bit according to the radio altimeter data. Fortunately they were flying at the next to highest set clearance, or one of those big trees might have swatted them. They did get mighty quiet there for a bit, just the backseater calling out the airspeed. Scary when the HUD field of view shows nothing but trees, no sky, which it did until they got most of the way up that hill.
Every accident over a certain dollar threshold has an inquiry. The findings of the inquiry determine causality and if that causality is due significantly to pilot incompetence, he likely won’t fly again. If the pilot did not greatly contribute to the accident, then they will likely keep flying.
The throttle cable connects to the Main Fuel Control or to the Main Engine Control. There was no electrical wire connecting the throttle lever to the engine, it was pure mechanical linkage.
Major Richard Bong, America's Ace of Aces, was killed while test flying an early jet fighter in August 1945. His engine flamed out at 200 feet and he bailed out, but his parachute didn't have time to fully open before he hit the ground. If his plane had been equipped with an ejection seat, it would have thrown him a good distance higher and there is a better than even chance that he would have survived.
Aren’t there usually about five levels of afterburner (”reheat” to the Brits), since he probably had all five injector rings going, one could make a linguistic case that all five levels of the afterburnerS were operating.
Those were much slower aircraft, usually the pilot or crew could get out. Not always, but they can't always get hold of the ejection handle either.
I think I'd rather have taken my chances climbing out of a WW-II aircraft, than with the early ejection seats. However that's not true of the aircraft those early seats actually equipped. The early ejection seats used what amounted to a light artillery shell to literally shoot the seat out of the aircraft. Latter seats use rockets to give more of a shove and less of a kick in the a$$. Lots of guys ejecting using the early seats suffered broken backs, compressed disks and other such injuries. Unless they manage to bang something on the way out, such an arm or leg that the "retractors" don't manage to pull running into the canopy rails or something, most pilots get up and walk away, unless they hurt themselves on landing of course.
The Soviets built better seats for quite a while. Now we've copied their basic design and ours are at least as good as the Russian ones.
The F-111 had an ejection capsule, and the B-1 was supposed to have one too. But they just couldn't get it to work properly. I saw some pretty funny tests of the various schemes they tried. In the end, it and the B-2 use ejection seats.
Thanks for the clarification.
Was one, MFC and/or MEC, and electronic device? I should know but everything sort of runs together after a while, especially things I was only peripherally involved with.
I wonder why they did it that way? I guess I could understand if the original had the cable linkage to a hydraulic or pneudraulic controller, and then they kept that for the newer version with an electronic engine control system
I used to be stationed at Tinker AFB, and in those days, IIRC, there were no electronic fuel control systems, and complicated hard to maintain things they were. Latter I supported the engine directorates as a contractor, on loan to our OK City (actually Midwest City) office.
I recall that the F-16 uses or used, two different engines. One a GE, the other a Pratt & Whitney. Was that the difference between having a MFC or MEC, or was it a A/B model verses C/D model thing?
I did not know it was stuck in wide open until till to late, while using a slide and some brakes to bleed off some speed (out of 70 mph) into a series of large whoops which were in a gentle turn.
It all happened pretty fast. As I rolled off the throttle to 50% and grabbed brakes, I saw that the motor was not coming off the pipe and the brakes had no effect on it, hit the kill switch and again no effect because the motor was glow plugging. At that point I spit myself off the bike and slid down the hard-tack track at 40-45 mph. The net result was a DNF, and several deep, painful & long to heal (even for a 22/23 year old) road rash strawberries.
Thanks for the info! It is good to know that a pilot’s career won’t be ruined by something that was not his fault.
Different car and situation, but I did have to consider ejecting once. Fortunately I got traction before the car would have gone over the edge...
I sold my BSA 500 single when I got married in 1978. It was a fine dirt bike, but most of the places I enjoyed riding as a kid are covered with houses today. There was no where to store it in the condo. C'est la vie!
The throttle was wide open.
Why not stick it in neutral?
... were you worried about blowing up the engine? That would be a fair trade off, if one wasn't at risk of hitting someone, or something of greater value.
It was not necessary to blow up the engine and it would have voided the warranty.
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