Always 2000agl for Robbos. 4500agl for BK117. The hard part, in a strong wind, is zero IAS. I don't have the same sucess in 20kts of breeze. The ground speed is noticeably off-putting. Lower collective until we have ROD >500fpm, then wait.
Random pitch, roll and yaw seem to arrive first. ROD goes thru 1800-2000fpm. Reduced cyclic effectiveness and increased vibration. Raise collective and watch Bloggs eyes as the ROD increases further.......Plenty of time for patter. Then recover. Forward (not excessive) cyclic works every time. Next demo try simultaneously lowering collective and note quicker apparent recovery - albeit with a greater altitude loss.
The Robbos always develop around 2000+fpm ROD. However, on quite a few occasions the VSI has done at least one lap of the dial! I have not been able to achieve this high ROD on consecutive demonstrations. Therefore I suspect the 2000fpm ROD may be the incipient stage. The AS350 and the BK give much higher ROD. They also seem to slip in to the state much more quickly/easier.
I am NOT a TP!. The CASA (Oz) syllabus reqires the exercise. I always demonstrate it to my students then let them have a go. QHI training is harder 'cos a lot of candidates can't get the R22, in particular, to enter the vortex ring state. I was introduced to the demo on the Robinson factory course at Torrance.
Last edited by Ancient Rotorhead; 26th Jun 2008 at 07:29.
Reason: 4500agl for BK117