The Nr Fairy
17th Feb 2003, 10:20
I received through the post a copy of the UK's helicopter specific GASIL, a safety publication. It is available on the web here (http://www.caa.co.uk/docs/33/srg_gad_heligasil2002.pdf).
Read the text below - taken from the last but one article.
------------------------
Stone me!
We are grateful to a reader of the Bell Helicopter Textron “Heliprops” for the photograph and accompanying information. The pilot of a Bell 206 had flown several trips with passengers during the day, and on the final trip was demonstrating a pedal turn from the hover at 600 feet to those on board at the time.
Having yawed through almost 360 degrees he applied left pedal to stop the yaw, but the pedal
would not move and the aircraft continued to yaw rapidly. Having lowered the collective lever and closed the throttle, the pilot was having to adjust the position of the cyclic stick to make the aircraft travel towards the safest available landing area during its gyrations. Eventually (and with his passengers screaming loudly that they were all going to die) the pilot managed to raise the collective at the correct point to make a landing in a level (but still yawing) attitude. There was no significant damage to the helicopter apart from the tail rotor drive shaft cover which had been hit by one of the main rotor blades during the gyrations.
The cause of the loss of control was a stone which had been carried into the cockpit with a previous passenger. The pilot continues ”It had lodged in the hole where the tail rotor pedal shaft comes up through the floor plate because the little foam rubber block, which is to prevent FOD from getting into that hole, was missing. I never before knew that those foam blocks are supposed to be there.”
That last comment from the pilot sums up the lose article hazard. However, we are concerned that he chose to even hover at 600 feet, with the attendant risk of an unintended descent and vortex ring generation, let alone perform this very uncomfortable “pedal turn” with passengers on board. Hopefully none of our readers would attempt such a thing!
-------------------- end of article
A few points occur to me. Apart from raising an issue about FOD, the tone of the article - "with his passengers screaming loudly that they were all going to die" - is reminiscent in parts of a tabloid. Secondly, isn't 600' outside the avoid curve for a fully laden JetRanger, assuming sea level ? Thirdly - I understand a pedal turn to be an aerobatic maneouvre which isn't done in the hover because it's a dynamic moving thing ? Was the pilot demonstrating a spot turn and we've got terminology mixed up ?
That particular article sums up that GASIL - lots of useful info, but you have to do your own analysis. For low time pilots like myself, to whom most of the accidents are likely to happen, should we expect better analysis to understand what happened ? If we analyse things wrong on our own or are they are explained wrong, are we not increasing the risk of doing the wrong thing in the heat of the moment ?
Read the text below - taken from the last but one article.
------------------------
Stone me!
We are grateful to a reader of the Bell Helicopter Textron “Heliprops” for the photograph and accompanying information. The pilot of a Bell 206 had flown several trips with passengers during the day, and on the final trip was demonstrating a pedal turn from the hover at 600 feet to those on board at the time.
Having yawed through almost 360 degrees he applied left pedal to stop the yaw, but the pedal
would not move and the aircraft continued to yaw rapidly. Having lowered the collective lever and closed the throttle, the pilot was having to adjust the position of the cyclic stick to make the aircraft travel towards the safest available landing area during its gyrations. Eventually (and with his passengers screaming loudly that they were all going to die) the pilot managed to raise the collective at the correct point to make a landing in a level (but still yawing) attitude. There was no significant damage to the helicopter apart from the tail rotor drive shaft cover which had been hit by one of the main rotor blades during the gyrations.
The cause of the loss of control was a stone which had been carried into the cockpit with a previous passenger. The pilot continues ”It had lodged in the hole where the tail rotor pedal shaft comes up through the floor plate because the little foam rubber block, which is to prevent FOD from getting into that hole, was missing. I never before knew that those foam blocks are supposed to be there.”
That last comment from the pilot sums up the lose article hazard. However, we are concerned that he chose to even hover at 600 feet, with the attendant risk of an unintended descent and vortex ring generation, let alone perform this very uncomfortable “pedal turn” with passengers on board. Hopefully none of our readers would attempt such a thing!
-------------------- end of article
A few points occur to me. Apart from raising an issue about FOD, the tone of the article - "with his passengers screaming loudly that they were all going to die" - is reminiscent in parts of a tabloid. Secondly, isn't 600' outside the avoid curve for a fully laden JetRanger, assuming sea level ? Thirdly - I understand a pedal turn to be an aerobatic maneouvre which isn't done in the hover because it's a dynamic moving thing ? Was the pilot demonstrating a spot turn and we've got terminology mixed up ?
That particular article sums up that GASIL - lots of useful info, but you have to do your own analysis. For low time pilots like myself, to whom most of the accidents are likely to happen, should we expect better analysis to understand what happened ? If we analyse things wrong on our own or are they are explained wrong, are we not increasing the risk of doing the wrong thing in the heat of the moment ?