The CNN article – HERE – is an almost perfect example of why-not to rely on anything the media tell you about an air accident. This one is classic.
Quote:….The propeller wasn’t working on one of the engines of the Indonesian military transport plane that crashed this week, killing at least 135 people, authorities said Thursday.
Quote:….The “initial finding” suggests the crash may have been caused by problems in the engine, said Air Marshal Agus Supriatna, the chief of the Indonesian air force.
So, which was it? There are, in any complex turbo-prop (prop jet) engine, gearbox and propeller combinations a number of potential scenarios where ‘elements’ of the entire system may fail. But, for almost every situation, the manufacturer has provided ‘counter-measures’ and procedures which provide solutions, in a timely, organised manner. The Herc is very well provided for in this area. I have no idea what procedures the ‘military’ use, but the aircraft has been around for a long while now, the manufacturer over a long operational history has, based on experience provided, at least in the civilian versions, comprehensive QRH to deal with nearly every possible combination of system failure, even multiple failures within a system. For example:-
Quote:…Engine failure during climb or cruise is not considered critical if the pilot refers to the recommended climb and cruise procedures for two- and three-engine operation in the Performance Information Manual. If an engine (or engines) fails during flight, shut down the affected engine in accordance with the Engine Shutdown Procedure. If a safe altitude cannot be maintained, dump fuel in accordance with the Fuel Dumping Checklist (performance and range must be considered in determining amount of fuel to dump). Place the flap lever to 15 percent or greater if two engines on one side are inoperative to obtain additional rudder hydraulic boost. Avoid abrupt or extreme rudder inputs above 183 KCAS when operating with additional rudder hydraulic boost.
Quote:…The reduction gear section decouples from the power section of the engine if a propeller attempts to drive the power section, and the engine negative torque control system fails to operate. As negative torque builds before decoupling of the engine takes place, airplane yaw may be noticed. However, there may be little or no difference in airplane feel, and the knowledge that an engine has decoupled must be gained from instrument indications.
Quote:…If propeller does not feather, a landing can be made with a wind-milling propeller; however, the drag and yawing tendency will be greater than with a feathered propeller, and excessive RPM and noise may be experienced. Maintain airspeed above 135 KCAS until landing is assured.
You can see from the parts quoted, that an engine failure, even with a propeller/ gear box failure is not a big drama; interesting certainly and no doubt a little challenging. Probably worthy of several beers and cautionary tale for the next generation of pilots. Tragically, not to be. So what really happened?, why do we have many dead instead of a great yarn.
There were two pilots and a flight engineer operating what was, until the event, a serviceable aircraft, the crew are (presumably) experienced and trained. Shortly after take off – there has been a series of events which led to the accident. It is now up to the investigators to put all the pieces together and unravel the ‘mystery’. In a perfect world, the report, which will take time should provide several key elements from which the manufacturer and operators may design and implement, or refine existing procedures, checks and handling techniques. This to prevent, as far as possible, the same circumstances reoccurring with similar results.
This is why organisations such the NTSB, TSBC etc. exist. I don’t know what authority or system the Indonesian military have to investigate, it may be a civilian effort or a combination. No matter, the important thing is that the investigation is done and seen to be done ‘properly’, for reasons which must be obvious to even the dimmest reporter or news editor.
This accident once again highlights the imperative for an expert, open, honest, unbiased investigation, completed in a timely manner by a trustworthy ‘authority’. Once upon a time, I’d have backed the Australian ATSB into being the best organisation to manage this investigation; alas, no longer.
If DPM Truss cannot see after this accident the urgent, pressing need for the ATSB to function correctly then it’s game over. After the botched mish-mash of bloody awful recent investigations and a series of next to useless reports, perhaps this accident, so close to home will focus his attention on why the ATSB service cannot be allowed to function as it does at present.
Real houses, real people, real aircraft, real blood, real carnage, real aircrew, real aircraft; ALL deserve real world answers and information which provides the ‘real’ tools for effective prevention of repetition.
Aye well, no steam, just exasperation, Lockhart, Pel-Air, Mildura, ATR’s. Newcastle; all potential incidents of equal magnitude and we get Beaker and his damn fool ‘Blog’. Someone give Wazza a shake and hand him his violin; he may as well do something entertaining, if not useful; while Rome burns.