Eng Crash On Camera

[downwash]

As Arte would say, "Ver-r-r-ry interesting." Typically, reports are confusing and incomplete. Isn't that why we have TSBs? Not being conversant with the later models of the type, I ask, is there a horn for hydraulic failure? ...Low rotor RPM? ...Engine out? Can somebody with some knowledge offer any more light on this while we wait for the boffins to tell us what they know (or think)?

[Nomex]

Astar BA - which was the accident type, has the same horn for hydraulic failure as low Rotor RPM - steady horn.

 

B2 has the same as above with an intermittent horn for high rotor RPM.

 

When you lose hydraulics in a BA, horn goes off, warning light HYD lites and you can use the accumulators for control inputs only until your speed is either increased or decreased to the appropriate hydraulic off speed to enable controllability (or land if you are in a low hover) then shut off hydraulics completely - BA does not have assist on tail rotor without hydraulics like the B! & B2 have. If you are at a high power setting in a hover and you lose hyd assist on the tail rotor in a BA - you immediately have to put a helluva lot of force on the pedal to keep straight.

 

The other pilot said he heard an intermittent horn - don't knowabout that one, other than if the initial emergency was engine problems and the low rotor horn went on, got the rotor RM back up, horn goes off, then bleeds off the rotor rpm, horn on?? I am not aware of any retrofits for the BA installing the high rotor rpm horn feature, but could be wrong.

 

Seems like a possible combination of failures?? I would say the TR was still working, but possibly without hyd assist which could account for the yaws when collective was likely being raised - other gyrations are similar to hydraulics off in a hover - overcontrolling?? Did seem like the pilot recovered well from the initial emergency whatever it was that caused the nose-down dive, then he appeared to try to flare - hard to say, but it looked like the rotor rpm was still OK until it hit the wall......

 

Even though the pilot didn't remember much, it sure looks like he did some good work to get it where he did.

 

????

[Nomex]

####.. In the preliminary report said that the accumulators each contained a pressure of 150 psi - would they be referring to the nitrogen charge?

 

Also, what is your take on the engine damage reported?

 

My opinion on losing hydraulics in a hover with a high power setting in the BA is that before anyone could react with enough force on the pedal (unassisted), you would be into a serious yaw, which could easily disorient the pilot and have the machine end up in a nose down attitude, before being able to control the yaw with enough pedal - thus the radio call of tail rotor trouble - also, an ingrained reaction will be to gain speed if you are in the hover (not excessive speed), but enough to help with the yaw and get into forward flight before you lose all hydraulics. Such a serious nose down attitude will result in gaining airspeed very quickly, probably quicker and more speed than you would want.

 

If in fact the hydraulics were lost, I doubt that the pilot would have been able to dump the collective hydraulic switch before things started going crazy and I would guess that the accumulators would be used up very quickly with large control movements, with the result that just as he levelled out and was flaring and as the machine started to go erratic, the accumulators may have become exhausted at different times, one after the other, resulting in uncommanded and pretty well unmanageable movements of the cyclic.

 

just some thoughts....

[skullcap]

Partial information on the TSB report would leave you to believe that everything was ok other than engine, and pilot's report would have you believe maybe hydraulics failed, although the pulley/pump assembly were attached(albiet ripped from mounts). The instant yaw to left while having accumulators charged(although they only had 150 psi - should be up around 210-220 psi) would make the pilot believe there was a t/r problem as he would not feel any hyd feedback only loss in t/r hydraulic assist.

 

But thats where in my mind the problem starts, why would a pilot with his experience not recognize after the intial shock the loss in hydraulics. He recovered from the hover to forward flight, unless he's totally fkd up he would have had time to observe which warning lights were on and begin to feel the hyd feedback and regain control, this seemed to just not happen.

 

 

Maggs, is the possible damage to the engine the result of an overspeed, this would explain left yaw, and loss of control. If the pilot didn't rectifiy the overspeed soon the a/c would become uncontrollable. I know of a B1 that got wrecked on the ground because pilot put fcu lever in emergency while strobbing t/r. The mechanic told pilot to bring it up to 100%, pilot new to Astar thought he meant 100%NG. It didn't work.

 

Horns and lights from eyewitnesses are usually not reliable, but TSB can tell which lights were on at impact if the impact was hard enough to break the filaments in bulbs. I would guess hitting the brick wall was hard enough.

 

sc

[Frequent Flyer]

Goodmorning All,

When doing winch training in a BA we do a full hydraulics failure in an OGE hover with high power settings. No giant yaw or loss of control. Machine is still quite stable and with a small increase in power plus forward airspeed the emergency is very very manegable. Of coasre in training you know the failure is coming. In real life a very different story.

[skullcap]

Ya, you said it FF, not sweat when you know about it. Have hovered Ba, b in 20 knots wind downwind with no hydraulices, key word when you know it. Probelm is not folks like you who do practice it is the folks who don't.

 

 

Hmmmmm, pretty quiet out there, what's going on Maggie?

 

 

sc

[skullcap]

I had a pilot working for me once who didn't notice an underspeed while picking up a load until the low horn when off, was a converted BA and no one had noticed the horn was not updated, the horn was going off a 335 instead of 360. He took to load of seismic bags to a nearby lake(frozen), and did a runon landing towing the bags like a waterskier, didn't want to punch them off as he figured the weight was a good thing to bring the rpm up if needed.

 

Another dude up north earlier(not working for me but the big bird) was asked by the engineer to check that the freewheel was disengaging(strange but they had just changed it) we think he meant after shutdown. Anyhow the pilot decided, 40 minutes before dark, 80 mile from home with TWO customers on board to check it out and preceeded to shut down engine and autorotated into swamp, no injuries thankfully, pilot wouldn't admit to being wrong, said it was a training fault, and was relieved of his duties.

 

Not all pilots are created equal.

 

Am sure we will eventually find out more mechanical information as to what was the cause.

 

 

 

sc