PPRuNe Forums - View Single Post - Entering autos: discussion split from Glasgow crash thread
Old 15th Dec 2013, 23:20
  #170 (permalink)  
SASless
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 71
Posts: 16,612
Do you fly anything powered by the excellent PT-6 Twin-Pac? Take a flight in a sim and ask the operator to fail the one-and-only drive shaft by surprise during powered flight. Unless you apply aft cyclic “right now,” you will probably crash and burn. How do you prevent this? Cyclic Back!
I taught in the 212/412 Sim.....and used that very event in training many Pilots.

I do not endorse your comment about the the "Crashing and Burning" due to the absence of Aft Cyclic during that situation.....in fact I would suggest that just is not the case at all. It might be part of the resolution of a problem but it alone is not the most important part of the response.

Reaction Time is the key.

Followed by use of the most critical response and then doing secondary control movements.

What is far more key to the outcome is the amount of delay in reacting to the failure and thus being able to minimize the decrease in Main Rotor RPM.

I think you put way too much emphasis upon "Aft Cyclic" as again....where and when the failure occurs is far more important and directly affects the amount of time that can elapse without a Pilot response to the failure before the situation becomes unrecoverable.

It is far easier to make up a small loss than a huge loss....that is plain commonsense. Any Helicopter Pilot who has an automatic response to lower the Collective when "Bad" things happen suddenly in a helicopter will probably live to see Retirement as compared to one who sits there wondering what the hell just happened before reacting. Anything you do to keep the Rotor RPM in the Green Normal Range is the right thing to do until you figure out the exact situation you are dealing with.

Rotor RPM is the very foundation of Life in Helicopter flying.....always has been....always shall be.

As you note....low power setting with a moderate IAS....and time is not as critical as compared to a very high Power Setting and a very high airspeed.....or no forward airspeed. In the latter....response time is very critical to defend against a large decrease in Rotor RPM. If moving the cyclic will assist in minimizing a loss of Rotor RPM then it should be done to the extent possible without causing other problems.

I will accept moving the Cyclic Aft will not necessarily hurt you in most situations....depending upon the amount of cyclic movement you make. Too much and you risk chopping off the Tail Boom on a 212.


Your other comment about the lack of Needle Split on some aircraft.......just how do you check for proper function of the Free Wheeling Unit? If you cannot split the Needles then that would be an indication of a malfunctioning Free Wheeling Unit.

If you have done much Maintenance Flying then you know that check is a normal test flight procedure....usually done on the ground prior to take off.

I am thinking you have some good ideas, and genuinely good intentions....but you are using much too broad a brush in some of your statements, in my opinion.
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