Tuesday, November 17, 2015

That must have been a wild ride . . .

The US Air Force is scrapping a brand-new gunship after an in-flight incident that left it damaged beyond repair.  Flight Global reports:

The US Air Force had to scrap one of its brand-new Lockheed Martin AC-130J Ghostrider gunships following a training mishap earlier this year, the service has revealed.

AC-130J Ghostrider (photograph courtesy of USAF)

While being operated at roughly 15,000ft, “the aircraft exceeded the targeted angle of sideslip until it departed controlled flight,” the report states. It “momentarily inverted, before being recovered after losing approximately 5,000ft of altitude.” The aircraft’s crew – who escaped injury – returned to base and landed safely, but the Ghostrider was rendered a total loss, having exceeded its operating g limits and design load.

There's more at the link.

That must have been a very wild ride indeed.  I wonder how many of the crew had to change their underwear as soon as they landed?  (I'm not mocking them, you understand . . . I'd probably have been among their number had I been aboard!)  On the other hand, the incident illustrates the strength and ruggedness of the C-130 design.  A lesser aircraft would probably have broken up in mid-air.



Jacquejet said...

So the test pilots got the C-130 in a fin stall. I flew 4000 hours in the 130 (A model gunships, trash haulers, and satellite recovery). In the 130 if the a/c is slipped excessively at low air speeds, the vertical tail can stall and the rudder will lose all effectiveness. Getting out of one is extremely difficult. A crew in my unit in Hawaii came very close to entering one and they were white as a ghost when they got back to the squadron.
These test pilots took 10000 feet to recover and the aircraft was totaled. Very lucky to be alive.

Anonymous said...

I'm surprised the crew was unhurt. They must have been strapped in otherwise they would have been bounced around the cabin.


Anonymous said...

Reminded of a comment I heard about a car crash "If I had known I was going to live, it could have been quite fun."

Bob said...

It's wonderful that everybody survived. BUT:

A pilot gets careless and now the taxpayer gets hit for another few million dollars. Seems that happens a lot more than it should.

The aircraft "exceeded the targeted angle of sideslip". No, the pilot did. Don't blame the plane.

My question:

How many multi-million dollar aircraft to we have to lose before we start getting serious about pilot behavior?

I would rather ground a few ego-bloated hot-doggers than continue to lose all these very expensive and probably obsoleted aircraft, since all our enemies now have SAM's of one sort or another.

The VC did not have the firepower needed to bring down one of these lumbering WW2 style relics (brand new notwithstanding), but don't kid yourself... There are missiles today that can easily ignore dropped flares, or active ECM, or a combination of both. Even lasers are now becoming powerful and portable enough to drop this thing like a lead balloon.

This aircraft, gung-ho as it is, neat as it is, expensive as it is, is just a fat juicy target nowadays that can utilized only in safe zones... such as totally defenseless American cities.

You have to wonder why the government keeps building them.

No, I am not anti Air force, or anti military or whatever, I am an ex-pilot (eyesight shot) and veteran that IMHO thinks our money should be going for aircraft with a much higher survivability ratio in today's very dangerous skies, and supporting pilots that do not endanger their crew and aircraft.

Anonymous said...

Military flying is eternally dangerous! Murphy or his cousin is always lurking. BZ to the pilot and crew that saved a flight crew, to hell with the damn plane! The administration, including our congress waste more money on useless/fun travel every year that we could buy all the Herc's we could ever use.

Anonymous said...

Why did the flight management computer allow the "sideslip angle" to be exceeded?

You never hear of such an incident in civilian aircraft like Boeing or Airbus.

Jacquejet said...

"Why did the flight management computer allow the "sideslip angle" to be exceeded?"
The C-130 is not a fly-by-wire aircraft, thus the flight management computer does not control the aircraft.

"You never hear of such an incident in civilian aircraft like Boeing or Airbus."
This is because civilian aircraft are not military aircraft.

Since the aircraft was being flown by pilots of the 413th Flight Test Squadron, I am assuming the plane was being flown by test pilots and they were in the process of doing flight test. It looks like they were exploring side slip data points and firing geometry. In so doing, it looks like the pilots found some data they didn't expect.

This is why aviation has TEST PILOTS.

Will said...

anonymous at 10:33

Airbus has had crashes due ENTIRELY to the computers overriding the pilots commands. Their software/design philosophy is that the pilot is subordinate to the computers. The pilot tells the computers what he wants, and THEY decide if it will be allowed. Boeing, and other US makers, do it properly, in that the pilot is in command of the aircraft.

Anonymous said...

Will -- the safety records of Boeing and Airbus jetliners are practically identical.

Jacquejet said...

You know nothing of the Airbus fly by wire aircraft. Me, I have flown the A320 since 1989 and may be the high time Airbus pilot in North America (certainly one of the top five). The aircraft does exactly what the pilots tell it to do.

Specifically, which crash are you referring. Since I can remember most of the relevant accidents, tell me which one you are talking about and I will educate you on your errors.

Will said...


The first one that comes to mind was an impromptu low level display, IIRC. Pilot made a low level pass over an airfield, with passengers onboard. Shouldn't have been done with passengers, of course. He was commanded to make the pass, although I can't recall the details. He ended up flying into the trees at the end of the field, due to the system not responding to throttle up command.

Not the last time it happened, I think. I've seen video.

The dumbest thing I've heard was the elevator input that was averaged between the two pilots, on the aircraft that crashed in the south Atlantic, off South America. That stick control system without feedback between the pilots controls is just mindbogglingly idiotic. Problem might not have happened if the pilots had been better trained, but the combination was fatal.

Peter said...

@Will: I think you mean this accident in 1988:


Jacquejet said...

Will...the first accident you refer to was at Mulhouse-Habsheim (ICAO LFGB), 26 June 1988. It was a charter flight and the passengers had won in some way a ride. The captain was the a320 program captain and the F/o was a training captain, both were highly experienced in other aircraft. The short description is that they were going to perform a maneuver caller Alpha Floor recovery, something that Airbus does at 1000 feet. This time the crew allowed the aircraft to descent below 100 feet radar altimeter. When the A320 and family slows to a critical angle of attack, just above the stall speed, the auto thrust system commands TOGA power, the aircraft maintains a high angle of attack and climbs out at an impressive rate of climb. Part of the fly by wire protections turns alpha floor off when the aircraft is below 100' and the gear is down, this also being the landing configuration. Having alpha floor engage during a landing is not desirable. Unfortunately, the crew didn't realize alpha floor would not engage during their low pass. When they realized that the shrubs at the end of the runway were actually trees, they went to TOGO. Only problem is with the engines at idle, there is an 8 second delay from idle power to TOGA (this is an FAA limit-8 second max time for this). The airbus hit the trees 5 seconds after TOGA was selected, turning the jet into the worlds largest salad shooter. Watch the video and you can hear the engines winding up.
When the plane hit the trees, the jet didn't stall, drop a wing or cartwheel. There were 63 passengers aboard including at least one in a wheelchair. Some were even standing. There were 3 deaths. All survived the crash, but were killed in the post crash fire.
The A320 performed exactly as it was designed to do and did exactly what the crew told it to do.

Ritchie said...

Seems like fin stall could be discouraged or eliminated in the design process.

Jacquejet said...

Ritchie...Fin stall is really hard to get into. I might have been wrong to suggest the Test Pilots got into one, but it sure sounds like it. This is a PDF link to everything you want to know about fin stall. The article begins on page 16...


Regardless, one of the missions of flight test is to explore the envelope of flight. I'm pretty sure this is what those guys were doing when they got into Mr Toads Wild Ride!

Will said...

Yes, peter, that's the video.


You have confirmed exactly the complaint I stated. That the system will not allow the pilot to command an input that it thinks is improper.
So, all those people died because the software designers decided that there would never be a valid reason to command full throttle with the gear down, and low and slow. Ohh, we don't want to bend the gear doors, or some other comparatively cheap expense, compared to killing a plane load of people, plus maybe a bunch on the ground, depending on location.

This sort of mentality seems to be rampant in Europe. I'm reminded of the one time that I drove my B-in-Laws VW GTI in the 90's. I took an offramp, and the following car decided to deliberately bunt me off the pavement. No idea why. I put my foot down, but it wasn't making much power, so I up-shifted in desperation, as the other cars' grill was fast approaching my tail. Instant power, and I rocketed around the ramp as he tried to catch me. I had the pleasure of watching him blow the turn onto the street, and impact the curbing that divided the road. He wasn't driving away with that damage.

Turns out VW limited power production in the lower gears, because the FWD format might spin a tire. Big f'n deal, my Turbo Colt wasn't a problem when it did that.
If that car had tagged me, I would have gone off the pavement and rolled down the embankment. I can't recall the LEO term for that maneuver.

Jacquejet said...

Will...Are you a pilot?