There are so many things that could have gone wrong.
Does anyone else remember the days before official safety departments and safety advisors?
Long ago our safety programs were self initiated and self conducted.
It was common for tradesmen to discuss at length any recent accident to workers, and even some notable older incidents.
What went wrong?
Who made a mistake?
What did we not know?
What is the weak point? When it breaks, which way will it fly? DON'T BE THERE!
That was our self taught safety program.
Staying at the same small hotel as helicopter pilots and mechanics I was a fly on the wall for a lot of these sessions.
One possible issue was what the pilots called the stick "Walking the Cabin".
If the pilot was startled and made an abrupt cyclic control movement, the rotors may subject to gyroscopic precession.
An abrupt backward movement of the cyclic stick may cause rotor and the stick to abruptly jump 90 degrees to one side.
That action will in turn cause an abrupt movement forward.
That action will in turn cause an abrupt movement to the other side
That action will in turn cause an abrupt movement backwards.
Rinse and repeat.
I listened to a pilot describe his own experience when the stick "Walked the Cabin".
Fortunately the action damped out before the helicopter came apart.
Another story was about a Vietnam era (MASH) helicopter setting up a new exploration camp.
All of the equipment was packed in large duffel bags.
A couple of bags would be set on each side racks. The helicopter would touch down at the remote camp and the ground men would pull the bags off and the pilot would immediately take off for another trip.
One one trip, a bag was not pulled clear but was left partly on one skid. The pilot thought he was clear and took off.
When the end of the bag dropped of of the skid it upset the equilibrium of the helicopter enough that the helicopter crashed. (From within a foot or so of the ground.)
One mechanic delighted in pouring over accident reports and sharing with us the most dramatic or outrageous accidents.
This was at a time when the Vietnam war was recently over and these pilots were ex US service pilots who had many hours flying time in combat and at times under fire.
There are just so many things that can catastrophically upset the equilibrium of a helicopter.
A possibility is a near catastrophic event, followed by pilot error that leads to an unrecoverable catastrophic error.
Waiting for the report.
www.theguardian.com
