PPRuNe Forums - View Single Post - Cabri crash at John Wayne Airport Sept 2018
Old 9th Sep 2018, 11:13
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ShyTorque

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Originally Posted by Helicopterdriverguy
Go on then please explain shy
HDG, For a start, read this (should be standard issue to every helicopter pilot):
https://publicapps.caa.co.uk/modalapplication.aspx?catid=1&pagetype=65&appid=11&mode=deta il&id=1127

The "Lucky Left / Rotten Right" saying was, I believe, coined in the USA, where traditionally the main manufacturers (e.g. Sikorsky) built all aircraft with counter clockwise main rotors.
It refers to a situation where tail rotor control is limited, such as a pedal jam or damaged tail rotor control system (note that I didn't include tail rotor drive failure). Basically, to safely land, the pilot needs to configure the aircraft on the approach so that the nose is "cocked off" to the "Lucky" side, i.e. LEFT in this case. As the collective is raised to cushion the landing, the increased main rotor torque reaction can be used to swing the nose of the aircraft to the right so it's briefly flying straight as the wheels/skids contact the ground, hopefully giving a good chance of avoiding a rollover. Additionally, to take advantage of the aerodynamic weather-cocking effect of the aircraft tail, arranging the approach with a crosswind on the "Lucky" side is also an advantage - certainly avoid a crosswind from the "rotten" side. It works!

However, the "Lucky Left / Rotten Right" only works for a counter-clockwise main rotor direction..... Anyone using that maxim in a helicopter with clockwise main rotors would be doing totally the wrong thing and would almost certainly lose control sooner or later.

I was involved in initial simulator trials in the mid 1980s, on behalf of the Helicopter Handling Sqn (Boscombe Down), to bring some sense to the lack of guidance given in the Puma HC1 FRCs and flight manual wrt to tail rotor malfunctions. This resulted in all RAF Puma pilots receiving tail rotor malfunctions simulator training from us. At least one RAF crew possibly later owed their lives to the training they received (their incident occurred over the North Sea and is included in the document in the link I posted above). It resulted in a successful ditching - despite the Puma HC1 having no flotation gear and I was told the aircraft was recovered almost intact.

Having realised later in my career after I had changed types a few times from aircraft with anti-clockwise to clockwise main rotor directions that I really shouldn't be remembering the "Lucky Left/ Rotten Right" saying in case "on the fateful day" I was flying a clockwise main rotor and got it wrong.

I thought about this for some time, then it struck me that the "Lucky" side is actually the retreating blade side, irrespective of the main rotor direction. I think I should be able to remember the blade rotation from the start up procedure.
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