There is a lot of information in that report that bears discussion as it relates to some issues raised in this thread. The test aircraft was the forerunner to the OH-58A.....and Bell 206. The basic concept seemed to be validating Glide Distance can be improved by using a raised collective setting rather than a full down collective setting.
G Loadings was shown in one graph....which had some interesting results.
Some of the comments about effect of controls, the actual bottom limit of NR they used in the test, amount of delay it takes for Torque to drop to Zero following an engine failure, time and height it takes to regain safe Nr to carry out a an EOL, and some other points.
The Test flying was done for a specific purpose but that does not mean the data created cannot be considered for what does tell us.
The fact the aircraft was flown power off at 65% Nr is note worthy as that is 30% below the Handbook Minimum Nr.....well beyond the 5% figure the PG has given as a Critical Point.
As we have been told that a mere 5% below the Normal Power Off Minimum Nr puts us into very dangerous territory. That would not be borne out based upon the test results. The test certainly confirms such a low Rotor RPM does not afford the capability to perform a safe EOL landing.....but that the aircraft flew well at moderate airspeeds with a very low Nr.
The difference in Nr caused by the movement of the cyclic in either the forward left quadrant or the aft right quadrant gives rise to questions of why that is for us that are aerodynamically challenged.
The Report certainly provides some insight into how the Rotor System reacts in very low Nr autorotative flight regimes. Page 4 and 5....just before the Conclusions Section that is on page 5 hold some very interesting comments. The slow decrease of engine Torque was noted as was the rate of increase in RPM during recovery from the Test RPM of 65% to the Normal RPM limit of 95% along with the associated increase in ROD.
There was also a comment about the results not being representative of any other type and model of aircraft or in conditions other than those noted in the Report.
The one thing it certainly does is remind us there are many ways to fly the same helicopter.....some that are within the Normal Limitations of the aircraft contained within the RFM as approved by the Certifying Authority and other non-approved and non-certified methods.
In keeping with the Nanny State Mentality of some here......the caveat that was not done in Big Bold Bright Type was "Do Not Attempt This At Home Kids!.....as it ain't kosher!".
Last edited by SASless; 18th Dec 2013 at 02:56.