They say confession is good for the soul, and it is probably more applicable to the aviation than any other effort. Pilots tend to not share their mistakes and oversights, the human weaknesses that each one of them does but kept secret. But these mistakes can serve a useful purpose. On the one hand, it is important to younger drivers hear veterans we have even been there done when it comes to of embarrassing ourselves in our race for flight. On the other hand, transparency in human factors always helps designers refine their products, as well.
My career was blessed with very few mistakes. I flew for 35 years without a scratch. More specifically, it does not mean scratches or dings on the plane. Does not mean that it was not bright red with embarrassment once or twice, had cagado, and the God of the aviation had looked out for me, while he was sustained in a serious ding to my ego. In summary, there was nothing wrong with the meter HUAL, head up and blocked. He just ignored. Here that an example of what can happen when inexperience, complacency and monitoring meet in the cabin, and it seems a close call.
The helicopter I flew was a French machine called an AStar. Its real name was AS350, mentioned in circles of the industry as an Ecureil, the French word for squirrel. They call it right; in some flight regimes, the machine was frankly, well, squirrelly. There is another word for this.
In general, the AStar is a fine, but has some design flaws. As each aircraft, at least the designed and built by man, which is most of them, the AStar defects and traps were cleared and refined over time, after the entry of the field. Such a design trap almost cost me at least the shame of a hard landing, if not something worse. In any case, the bottom line, that had occurred the incident was one, it would have been really a collaboration between the French engineers and yours. It focuses on original AStar white plastic oil depot.
To save weight and cost, always considerations in the design of the aircraft, especially helicopters, the AStar originally came to the service with an opaque white plastic oil depot, something akin to a jar of whole milk. This jar of oil had a view of the indicators on their side that, in each AStar I never flew, was conveniently hidden half way behind the dam. He took an open hood, a flashlight and a small ladder to see bandwidth, as well as several seconds from beginning to end. My usual method of checking the oil level was look the real level of oil in the tank, what dark line was visible through the plastic.
That was what I did one spring morning when, in a contract for hospital, I was sent for a flight of emergency shortly after the submission of reports to the service. Audible barked, they checked the fate, he ran up to the helipad and met the flight nurse. Walking by the helicopter, I did my usual checks of the large pieces, most of the smaller parties and all fluid levels - I thought - then leapt from the cabin. They produce the motor, flipped on the radio, and soon he was willing to commit the aviation. I thought.
Nominal take-off, climbout simple and soon are redistributed to 2,500 feet. Then, with no warning, five miles from the launch pad, par needle made a little whifferdill, bobbing once, twice, then bouncing from zero to high and back again in a funny imitation of a metronome. This was not a good thing. (VI) the meter with some interest, and of course dancing continued even needle the whole width, never settling in any particular value. The nurse, I reported that we were heading home, and then standard 180-degree turn back to heliport to sort things.
I landed, turn off the engine and went through my mental list of what could be the problem. It could have been the gauge are known to fail. Perhaps was the connection loose? Helicopters rattle and hum a little, making attachments to undo. Does perhaps the oil...?
I thought that the design of the system of couple: in AStar, indicator of pair is called a wet indicator, since it depends on the pressure of the fluid to work. Mentally traced the route of this line of oil and the indicator to the engine, he arrived in the reservoir itself. Subsequent revelation increased my store of experience and we hope that some other AStar pilots also.
Lift the fairing, caught my step stool, a flashlight and a key to check the actual level of oil in the tank. To my amazement and disgust, the tank was almost empty. A puddle of oil, enough to cover the bottom of the tank, was there present. I looked again. The "level of oil ' would like to see on the checks was nothing more than a stain of oil inside the plastic tank, embedded there after several fill ups, always at the same height." The plastic had absorbed enough oil to highlight what is expected for the entire world as a tank with plenty of fluids.
I shook my head, cringing at the possibilities. Modern gas turbine engine is cooled by two things: air compressor and oil. Reduce either of those two, and a turbine rapidly overheating. At one point heat will make the engine to fail. I had no idea of how close would be to get to an engine failure that day, but had to they have been a few minutes at most. It is a thing of gas; implementation of oil can cause similar adventures.
The conclusion was that there was nothing wrong with the meter another, equally important in the cabin - HUAL, or head above and blocked the indicators. It was working well; I simply decided to ignore it, assuming that the oil level was very well, as it had previously been and took off. Since that day, I made sure I was looking at the real oil rather than a stain and residue of a tank where oil used to be.
He presented a report with the manufacturer about the possibility of similar incidents. If my documentation or not does not say and more doubt, but later model AStars arrived for duty with metal oil tanks, and a view not stainable indicators forced drivers physically check the level. I certainly did after that. And I paid more attention to HUAL indicator as well.
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