PPRuNe Forums - View Single Post - Helicopter down outside Leicester City Football Club
Old 29th Nov 2018, 06:00
  #859 (permalink)  
DOUBLE BOGEY
 
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
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CHOPJOCK, I am not going to trash your ideas because sometimes, lack of doctrinal thinking and dogma can be the mother of invention. However, I sorry but in this instance you are "droning" up the wrong tree.

You see the TR is there to stop the torque applied to the rotor head, spinning the fuselage once the undercarriage friction with the ground is not longer present. To make the TR efficient, it is placed a long way down the tailboom to give some leverage. This provides the added advantage of "Keel" surface. That is to say the surface of the fuselage and tailboom combined, when pushed through the air at speed, provides an element of anti-torque reaction all on its own. However, this "Keel" surface is not really effective until the forward airspeed is well above 70-80 KIAS. Now I am not a Test Pilot so my numbers here are just a guess but you can get the idea. The more power you apply to the rotor head, the more "torque" is trying to spin you.
So armed with this new knowledge, you can understand that what you propose, scuttling across the football pitch then zooming over the stand, you will still be below the speed where any benefit from the keel surface is not present. Added to the requirement to apply lots of power, to accelerate quickly, and you can understand that a TR failure anytime during your procedure would leave you, at worse case, moving forward across the ground, spinning like a an angel with a broken wing towards the obstacles in front of you. This set of circumstances is extremely difficult to resolve.

In recognition of the critical role the TR plays, especially in the low speed, low height part of the flight envelope, the certification requirements for the TR system are very comprehensive and the design failure rate much lower than other systems that may for example, be duplicated. This is why this accident is so significant if indeed it proves to be some kind of design fault.

This problem, the heavy reliance on the TR, has plagued designers and performance systems since Sikorsky donned his pork pie hat. It is nothing new.

Many factors come into play when a TR malfunction occurs and the actions of the pilot are just one aspect. Design characteristics, Power Setting, airspeed, height, wind direction etc all have a influence on the outcome.

I understand your concern, hanging around in the low speed envelope increases the exposure to the impact of a TR failure and you are certainly correct in this assumption. However, your proposal does not solve the problem as the exposure remains critical throughout your proposed take-off envelope and marginally improves as speed (>80 KIAS guess) and height is gained.

If you are a Drone Pilot and you do it for a living, big respect. I had a drone for my Daughters Wedding this year and it and the operator were awesome.

I hope this post helps you to understand why so many are perplexed by your proposal.
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