BUFF crash

http://www.stripes.com/09/feb09/crash_report.pdf

All,

The report on the Buff crash on Guam has been out for a time now. I think everyone has had a chance to read it and mull it over. If you haven’t the above link will get you there.

Our Bob blog has not said much about it and I value your experienced opinions.

After reading the report I was horrified at the description of the crash. I can’t , for the life of me, imagine a B-52 getting that out of control that quickly. I don’t understand and can’t swallow the explanation of a runaway stab trim. scenario unraveling that quickly to hitting the water in a near vertical dive at almost 600 knots. How many times have you participated in simulator rides with runaway trim? How many sims have you given to students over the years with this kind of results? Instinctively I recoil at the idea that a runaway stab could put the nose that far down that quickly. I know that the Buff increases in positive trim as it gets faster – until Mach tuck.– No mach tuck at this altitude possible.

I suppose that what little they could recover of the aircraft didn’t give them much to analyze. It seems to me that an investigation of the auto-pilots roll in this accident would be a better avenue. Putting myself in the situation and knowing the younger crowds flying habits and experience, leads me to suspect an auto pilot induced roll to inverted flight with unsuccessful recovery from the unusual attitude. There wasn’t a single word in the report about unusual attitude recovery.

I know of at least one incident at the 20th BS a few years ago were a young guy allowed the auto pilot to get him near inverted on a bombrun. He came very close to killing himself and his crew and destroying the aircraft. Only a high G recovery that badly damaged the jet saved them.

I have, on many occasions, had the auto pilot attempt to overbank the jet on altitude hold. I never trusted the damn thing for that reason and always monitored the bank closely when using the roll knob. Also as much as I liked the young pilot involved in this accident, I was uncomfortable with the over-the-top explanations they gave in the report to exonerate the crew of responsibility for the crash. Again absolutely no discussion of unusual attitude recovery. Even if you buy the runaway trim story, the next part of that string is recovery. Every scenario involving runaway trim in the EP sim involved recovery from the unusual attitude caused by the trim problem.

Also it is completely obvious that flight over water, on a calm day, with no land around, leads to disorientation. Again not a word in the report about a lack of horizon and its impact on the ‘pilot” trying to recover from an unusual attitude.

I never flew with the pilot, but I do remember discussions about his performance at the 20th BS and his weakness during pattern operations at night – with no horizon- recognizing over banks in turns. The report would have you believe this crew was above reproach in responsibility and that runaway trim is unrecoverable in the B-52 for even experienced pilots.

Don’t’ buy it! What do you think?

Ponch

4 Responses to “BUFF crash”

  1. The Chuck says:

    Reading the report at the Stars and Stripes link you provided, there is enough data to make assumption that neither agree with some of their conclusion nor are possible to prove–or disprove.

    It’s been almost a year since the Air Force and the nation lost six warriors, and I’d never intentionally say anything that would suggest they were anything but the heros they were as they gave their lives in defense of freedom.

    At the same time, the distinguished veterans who read this blog know that we’ve made a life out of learning from the disasters of others. Properly investigated aircraft accidents should give some pearls of wisdom, no matter how small, to those that are left behind–so we become better. Or at least those are still flying the B-52 can become better–we’ve only got a few of them left.

    FACTS:
    1. At 0859L Balls 53 took off from Guam intending to perform a flyby at 1015L in downtown Agana.
    2. The crew made contact with the flyby POC at 0925L
    3. At 0927L 2xF15Es took off from Guam intending to be 1 min behind Balls 53 in a flyby.
    4. Approximately 0935L, Balls 53 TOT was changed to 1000L.
    5. 0940L Balls 53 and the F15Es accept MARSA
    6. Balls 53 was orbiting at 14,000 feet, 30NM north of Guam at “approximately 0953L” when the crew reported their intention to leave the holding area and descend–they entered a left turn and the 2xF15Es turned away from Balls 53 to gain their spacing–they last they saw of Balls 53 was it in a left turn towards Guam.
    7. Balls 53 continued the left turn and began a descent IAS was 240K.
    8. They traveled about 5 miles as they lost the 14,000 feet
    9. At 0955 Balls 53 crashed 30NM northwest of Guam, the pitch was 33 degrees nose down.
    10. Stab trim was at 4.5-5.0 degrees nose down at impact.

    The investigators have no way to determine if the airbrakes had been moved around …
    Looking at figure 5 on page 23 let me make a guess at what “might have happened” but we’ll never know …

    Dang, the table won’t fit … I’ll try in a separate posting … you’ll know the context of the table via this comment.

  2. John farese says:

    All, I can’t sign in anymore!! Chuck if you get this can I have a new password? I agree. When I saw this accident I thought, “speed down” and improper trim technique, common error. Self induced nose low trim, high air brake setting, and late recovery with no use of trim. We all know the pilot was extremely weak, both as a co pilot and an aircraft commander. Nice guy, poor flying skills. Not sure where all there glowing remarks came from. The whole crew sounded like supermen, we all know that is BS. Since they are bringing back SAC(in a way) they should make instructor upgrade training as difficult and challenging as before.

  3. The Chuck says:

    I’m not so sure “SAC” is back, it’s going to be something more like a missile command as eight-engine bombers have been marginalized via the purge of its leadership corn years ago.

    I make a table with my comments on another post, but it’s based on the same principle as John’s comment, which is probably what most of us thought from the beginning.

  4. The Chuck says:

    Figure 5, page 23, shows the breakdown of a little more than 1 minute of disaster. It provides the data for a “seconds to live part three” class, if anyone was brave enough to take it on.

    At 0953:11 the descent begins … and 6 seconds later the nose is 3 degrees high and they have 12 degrees of bank — sounds like a turn-induced pitch-up along with some kind of airbrake input without enough trim or forward yoke to control it. In addition, because the TOT for the flyby was stepped up from 1015L to 1000L, they’ve put themselves into a hurried situation–gotta get turned, down, and sped up …

    8 seconds later, the nose is 2 degrees down (a change of 5 degrees) but the airspeed hasn’t increased–suggesting they haven’t pushed in the power (yet) and are still fighting the airbrakes pitch-input (maybe hoping to descent faster) …

    5 seconds later they are 7 degrees nose low (another change of 5 degrees of pitch) and the bank is 7 degrees beyond what his target probably was … and 4 knots have been added to the CAS.

    6 seconds later, the pitch is 11 degrees nose low (another drop of 4) and airspeed has increased by 14 knots but the bank has reduced back to just under 30 — obviously he caught the bank and made an adjustment on the ADI and has he’s probably pushed in some power … and he’s thinking about his pitch and he notices the VVI is pegged

    maybe goes to AB 0 — nose drops a lot,

    6 seconds later, the pitch is 23 degrees nose low and the bank is cranking up to 40 and increasing–suggesting a right hand pull on the yoke … what’s the left hand doing? Hooking up a mask or looking for something in the bin … checklist? Comm card? Spit cup? Something else?

    4 seconds later the bank is at 50, but he’s got it under control–probably two hands on the yoke–but pitch is 30 degrees low…and he’s probably concentrating on the bank

    5 seconds later the bank is nearing 30 and reducing and the pitch is still 30 degrees low and CAS is 340 and the interphone is probably filled with warning and comments from the crew … you’d think …

    5 seconds later the bank is at 10 and reducing, the pitch is at 23 and the yoke is probably in his lap … and if his left thumb is on the trim button, human ergonomics would default to a nose down trim ….

    4 seconds later the wings are at 0 bank but the nose is still 23 degrees low and the airspeed is approaching maximum allowed — the nav team should be issuing a loud warning ….

    6 seconds later, he’s hold the yoke in his lap and the trim is probably against the stop — he might even noticed what has happened here and is frustrated with himeself … CAS is 435 — more warnings …. maybe he chops the power …. and the nose drops

    2 seconds later pitch is at 29 degrees low … most certainly he knows he’s out of trim because the wheel’s not moving and maybe he repositions his thumb …

    3 seconds later CAS is 495 pitch is 33 degrees down the mach-tuck is kicking-in and forcing the nose down as the yoke is in his lap and the trim is slowing reversing …

    2 seconds later CAS is 510, pitch is 33 degrees nose low … trim is approaching 4.5 ND … people are starting to think of egress …. too late.

    VVI is 28,464 feet per minute and they are just barely above 2000 … out of time.

    The dash one says when aircraft control is lost at any altitude or when the warning to eject is given below 2000 feet … but when was control lost? When did the crew know? When did the pilot know?

    When did we know?

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