PPRuNe Forums - View Single Post - VH-PGW PA-31P-350 15 June 2010 Crash Investigation
Old 15th Jul 2010, 23:05
  #41 (permalink)  
Mainframe

Check Attitude
 
Join Date: Nov 2001
Location: Queensland, Australia
Posts: 476
Likes: 0
Received 0 Likes on 0 Posts
had a long think about things after reading the preliminary report.

There was a loss of power on one engine, possible technical cause / failure.

There are some human factors issues inside and outside the aircraft.

With regard to the technical issues, the investigation will be hindered by the degree of intense fire damage, yet some clues may emerge.

Was the aircraft given a quick circuit after the recently completed 50 hrly or was this the first flight after maintenance?

Nothing like a leak check after a maintenance test flight. Was the daily inspection unintentionally interrupted and maybe an oil cap left off?

Was there an engine driven fuel pump failure and vital actions taken to switch on the electric fuel boost pumps to restore fuel flow?
We may never know because the switches are plastic and there was a fire.

Was the engine developing any power or was it shut down regardless.

Given that it seems the prop was feathered,
it must have been shut down before the RPM decayed to the RPM below which the pitch locks would have engaged to prevent feather.

ATSB will do their best to sort out the technical issues despite the fire damage.

The human factors side:
Loss of an engine in a twin engined aircraft removes the aircraft from the "Ops Normal" status.

Presented with an abnormal situation, a PAN call would have alerted ATC that there was an emergency potentially developing. A PAN call was not made.

This may have prevented the following happening:


Soon after, ATC instructed the pilot to descend to 2,500 ft
and advised that Richmond airport was two miles to the south of the aircraft if the pilot could not maintain height.
As other posters have commented, if it was the intention to get back to base at Bankstown, rather than attempt a landing at Richmond,
maintaining as much altitude as possible in a drift down till overhead Bankstown could have made a difference.

We all have the luxury of hindsight, and plenty of unpressured time to think out all the possible options in the comfort of our home or workplace,
with a cup of coffe nearby.

The PiC had the deck stacked against him and not much time or performance to explore options.

And yes, I have been in a similar scenario in a GA twin with a broken crankshaft. I made the PAN call and ATC responded very professionally.

I did not abdicate command of the aircraft, I communicated my intentions and flew my revised plan.
I drifted down to 6,000 ft and then was able to hold that until overhead a suitable aerodrome, then circled down and landed.

Good luck, good recurrent training and plenty of experience helped ensure a satisfactory outcome.

The TSIO 540 will run for a limited time at maximum power, then it will start to melt things, but needs about 10 to 15 minutes to do so.

The Whyalla Air Chieftain managed 15 minutes at Max Power on one before it finally gave up.

I still have faith that ATSB will come through with a factual report, although they did invoke junk science in the Whyalla report.

(Whyalla was ultimately found to have been one of many Lycomings suffering a broken crankshaft due to manufacturing changes.)

Keep the discussion going, regretably it won't help the deceased, but may prompt awareness and thinking that may save your own life in the future.

MF
Mainframe is offline