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Medium Tail Rotor Drive Failure


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Can't speak on Rob's behalf.

 

My "guess" is that power management begins with properly using the cyclic, so you don't have to yank the collective at the end to get yourself out of a bad situation. Velocity has more lift potential than pitch angle. :fart:

 

Ha zzz y

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There are a couple of things missing in this thread.

 

First, it is impossible to simulate a tail rotor drive failure with any accuracy. This was explained to me by Nick Lappos himself. The reason being that the tail rotor, when turning, is 1.4 times the fin area of most modern helicopters. So if that tail rotor is stopped, there goes almost 75% of your keel affect. No combination of speed/power will maintain forward flight. Hence the reason most RFM's call for autorotation in case of drive failure.

 

A tail rotor control failure on the other hand leaves the keel effect intact and it MAY be possible to maintain forward flight.

 

Second misnomer is people trying to duplicate emergency flight characteristics with ANY commercial simulator, including level D. Again, Nick says that even research simulators used by the manufacturer are not 100% accurate when it comes to simulating OEI performance, tail rotor failures, etc. The sims we get to use are nothing more than procedures trainers, great for seeing exactly what gages and instruments will look like in a failure and how to react to them, nothing more.

 

The bottom line is, never develop emergency flight procedures from sim experiences. Thats what the RFM is for.

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There are a couple of things missing in this thread.

 

First, it is impossible to simulate a tail rotor drive failure with any accuracy. This was explained to me by Nick Lappos himself. The reason being that the tail rotor, when turning, is 1.4 times the fin area of most modern helicopters. So if that tail rotor is stopped, there goes almost 75% of your keel affect. No combination of speed/power will maintain forward flight. Hence the reason most RFM's call for autorotation in case of drive failure.

 

A tail rotor control failure on the other hand leaves the keel effect intact and it MAY be possible to maintain forward flight.

 

Second misnomer is people trying to duplicate emergency flight characteristics with ANY commercial simulator, including level D. Again, Nick says that even research simulators used by the manufacturer are not 100% accurate when it comes to simulating OEI performance, tail rotor failures, etc. The sims we get to use are nothing more than procedures trainers, great for seeing exactly what gages and instruments will look like in a failure and how to react to them, nothing more.

 

The bottom line is, never develop emergency flight procedures from sim experiences. Thats what the RFM is for.

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it's simple.. the right hand is your collective hand... manage rpm and mp properly is what i believe he's getting at.... ;)

 

 

man, oh man... i cannot believe i wrote that!!! of course the left hand is the collective hand!! i shall now accept all deserved "what a stoopid thing to type that was" comments.... :huh: :huh:

 

hazy, of course, said what i was thinking!!!!

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In all my years flying I never had an emergency that I could have trained for, they always seemed to happen at the most inapropriate time and it was basically responding to a situation and survival. My biggest concern was knowing what the machine I was flying was capable of doing and each machine was different, even the same category and model.

 

Back to my Navy days, we had recently overhauled HUP-3 Piaseki (year prior) in the hangar doing 300hr. inspection. One of the checks was to put the rigging pins in the heads to check that all controls were at the required settings. Upon lifting the pichhorn on the M/R head the unit came up and would not go back down to fit the rigging pin. Checked in the cockpit and found that the screwjack that contolled the pitchchange mechanism was off it's mount on the transmission.

 

Without going into to much detail, the main rotor system is controlled on both heads by screwjacks mounted on the respective transmissions, the screwjacks go up and down controlled mainly by the collective (initial power setting). Inside the screwjacks is a locknut that prevents the screwjack from coming of the stud mounting on the transmission.

The locknuts had never been installed at overhaul and nobody had ever pulled the collective to it's maximum IN THREE HUNDRED FLIGHT HOURS, TALK ABOUT THE GOLDEN HORSESHOE.

 

I guess what I'm trying to say is, a person reacts to a situation in what he/her has been exposed to, if you have time.

 

Don

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