The board has noticed, particularly in the context of normalised deviance, the Squadrons blase approach to wind and especially whilst conducting Special Operations Assault Approach. Furthermore it was a combination of factors: height speed and lateral distance from the ship and tail wind that contributed to the crash of BlackHawk 221. Moreover the energy that the aircraft carried into the approach could not be successfully dissipated in the available space whilst keeping the aircraft within the flight manual engine management and performance limitations. The resultant flare terminated in an extreme attitude and in the presence of a tail wind. Under these circumstances the engines were unable to respond to the power demands in a timely fashion and the BlackHawk responded as should have been expected.
The report goes on to say:
Para 2.23:
Even at a contingency power rating, the engines could not produce sufficient power to simultaneously overcome the drag to accelerate the rotor and produce sufficient lift to arrest the rate of descent
Later:
Para 2.25:
Immediately prior to impact the helicopter was descending at 1800fpm with an effective airspeed of less than 5kts and with significant power applied. These conditions are within those described in the Flt Manual to be most favourable for developing Vortex Ring.
The report leans towards VR as the cause.
I suspect (given the circumstances, the main conclusion (above) and para 2.23) that what they actually mean is: Settling with Power and not Vortex Ring. [I re-iterate: VR is an aerodynamic state and SWP is an engine performance state].
This guy came round the corner (into wind and with a gentle descent already on), ending up pointing the helo downwind (within 10degrees) with serious nose up attitude and found he was (a) still moving fwd too quickly and (b) still descending. He went from 20 - 100% (Max Cont) within 2 seconds to arrest his momentum and found that this was insufficent to arrest his trajectory. Blades slowed down exacerbating the descent - impact.
Bottom line from the BOI:
Supervisors from Command to blame - lack of supervision and Training.
No disciplinary action taken
