MIflyer
1st Lieutenant
The formal mishap report on that V-22 crash over near Japan is out.
It seems the crew received a "chip warning" indicating that one of the gearboxes was shedding its guts but elected to proceed to an airfield a significant distance away rather than land at an airfield that was only 10 miles behind them. Enroute to the airfield they had chosen to divert to they received more chip warnings, one after the other, followed by a chip detector failure warning. They were in the process of getting set up to enter the pattern at the airport when a gearbox failed and the aircraft crashed, killing all on board.
Obviously, multiple poor decisions were made, but you have to wonder how often chip warnings occurred on a normal flight.
When I was at Oklahoma City Air Logistics Center the decision was made to install an "Acoustic Crack Detection System" in all C/KC-135 aircraft. This was a system that would listen for cracks occurring in the aircraft structure and warn the crew. It seemed like a good idea at the time, given that the KC-135's were planned for reskinning and re-engining that would extend their life well into the 21st Century. The test hardware seemed to work fine, but when the production hardware arrived they found that the sensors were on the low side in terms of sensitivity so the gain in the amplifiers had to be turned up. And like any amplifier, you increase the gain, then you increase the noise you amplify. Aircrews started reporting many more alarms, and, of course, when something keeps giving false positives you tend to ignore it. By the this time the individual who had successfully fought for the acoustic crack detection system had gathered his awards and transferred, leaving his replacement to figure out if the system could even be saved. He wrecked his car one night coming home very late after a 18 hour plus day on the job. I don't know what ever happened with that system, but I'm pretty sure that false indications of cracks occurring became just one more stupid thing to worry about for KC-135 crews.
It seems the crew received a "chip warning" indicating that one of the gearboxes was shedding its guts but elected to proceed to an airfield a significant distance away rather than land at an airfield that was only 10 miles behind them. Enroute to the airfield they had chosen to divert to they received more chip warnings, one after the other, followed by a chip detector failure warning. They were in the process of getting set up to enter the pattern at the airport when a gearbox failed and the aircraft crashed, killing all on board.
Obviously, multiple poor decisions were made, but you have to wonder how often chip warnings occurred on a normal flight.
When I was at Oklahoma City Air Logistics Center the decision was made to install an "Acoustic Crack Detection System" in all C/KC-135 aircraft. This was a system that would listen for cracks occurring in the aircraft structure and warn the crew. It seemed like a good idea at the time, given that the KC-135's were planned for reskinning and re-engining that would extend their life well into the 21st Century. The test hardware seemed to work fine, but when the production hardware arrived they found that the sensors were on the low side in terms of sensitivity so the gain in the amplifiers had to be turned up. And like any amplifier, you increase the gain, then you increase the noise you amplify. Aircrews started reporting many more alarms, and, of course, when something keeps giving false positives you tend to ignore it. By the this time the individual who had successfully fought for the acoustic crack detection system had gathered his awards and transferred, leaving his replacement to figure out if the system could even be saved. He wrecked his car one night coming home very late after a 18 hour plus day on the job. I don't know what ever happened with that system, but I'm pretty sure that false indications of cracks occurring became just one more stupid thing to worry about for KC-135 crews.
