AH64 APACHE
17th Jul 2003, 18:16
INteresting piece in FLyer this month on VMC rollover on single engine. Now when I went through my training at an intergrated school - I am sure I was never told about this particular phenomenon. Can anyone enlighten me as the flyer article was not that informative as to causes and the recovery.
Should we not know this if we are doing an ATPL???
Anyone else out there have the same experience?
Vmc, or Velocity- Minimum Control is the speed at which the rudder can no longer compensate for the adverse yaw created by the asymmetrical thrust and the aircraft becomes uncontrollable. This is called Vmc rollover. The PTS calls for the demonstration to be conducted in a specific fashion. Typically they want the left engine failed (on an aircraft with both engines turning clockwise), with that prop windmilling (Creating max drag on that side). On the right side they want max. manifold pressure and prop full forward (max power) creating the most possible asymmetrical thrust. The nose of the plane is then lifted, keeping the heading straight with the rudder, until the airspeed slows to the published Vmc speed or the rudder pedal hits the floor, which ever occurs first. Then the nose is pulled up ever so slightly so that the nose can no longer remain on the desired heading and the recovery is executed. Recovery requires that you lower the nose and reduce the power on the good engine simultaneously and return to the original heading. All of this is to be executed at a safe altitude, but low enough so that the "good" engine generates close to full power.
Hope this helps :)
Interestingly, this article -> http://www.avweb.com/news/safety/185267-1.html says that
Similarly, given how poorly some twins do on a single engine, we thought we would find more examples of the multi-engine pilot's worst nightmare, the VMC rollover. Again, only seven of the 545 accidents -- about 1 percent -- we reviewed appeared to be genuine rollovers. That's a better record than we imagined, suggesting that VMC-roll avoidance training may work.
AH64 APACHE
28th Jul 2003, 18:16
Flyer was suggesting that the rollover recovery was a form of spin recovery induced by the inability to stop the yaw from asymmetric thrust. The recovery carried out by the pilots in the flyer article was done in Eight thousand feet!!! Surely if it was just a simple stall recovery needed then that would not involve that large a loss of height?