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Originally written by TC 2009

Google earth location: Archerfield and Caloundra airfields Queensland

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 "RotorWay Fun Times - Part one"

 

The fatigue flight test program was going well and we were accumulating a wealth of in-flight data from the strain gauges which were stuck like leaches over airframe and rotor systems. Youtube has a video of a demo run which is slightly boring for the uninitiated but shows all the strain gauges and computer gear..

The flight test program was quite specific and disciplined as not only were we hopefully validating the kit manufacture's data but also plotting stability and assessing myriad of other requirements for certification requirements in Australia.

Notes from FAQ - youtube video

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All flights were done at gross weight

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The VHS video camera for simplicity was mounted upside down to the RH cabin roof. Its purpose was to record instrument parameters and flight control positions "just in case".

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My microphone also recorded directly to the camera as I talked through every action/task

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The yellow plastic paintbrush was taped to the cyclic stick so that all cyclic movements were visually recorded

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Two tapes on the left leg of my flight suit indicated full fore and aft travel for an unusually accurate visual measurement of cyclic stick displacement when plotting cyclic travel V airspeed

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The 386 computer was "big time" in those days and the additional 16mb of ram required to run the Amlab software cost over $1000 - equivalent to 2009$3000.00! The computer and monitor were both 240 volt and connected to an inverter. On one trip, I couldn't avoid a very fine misty sun shower and had visions of being the first pilot to be electrocuted by household mains power in flight when the monitor copped some moisture in the back vents and blew up.

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The Squiggly lines on the monitor are the various strain gauge channels feeding into the computer. You can see for effect the resultant when I simply wiggle a blade on the ground. Which goes to show that rotor blades prefer their designed operating RPM to reduce slow speed root bending moments

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The rotor blade strain gauges feed back down thru a slip ring as indicated by the aeronautical engineer

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There were strain gauges inside the tail boom where it joined the main frame

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The black marks on the LH rear of the tail boom where the tail rotor slip rings were mounted, were caused by an electrical fire in flight - which was interesting experience at the time
 

My flight note assessments from the time showed that this particular machine had/was:

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Unstable at higher speeds (I noted it down as flat plane effect)

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Underpowered at gross weight or DA + 2000 Ft AMSL

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Limited useful load

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More susceptible toward negative G than the R22

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Extremely smooth and quiet engine probably contributing to less airframe and pilot fatigue

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Limited range and endurance in comparison to an R22

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Met (exceeded) manufacture's published VNE with forward cyclic stick displacement for approx 15 Kts gust (118 Kts exceeded)

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Positive progressive cyclic stick displacement

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Poor tail rotor control in tail wind conditions exceeding 10 kts

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Smooth rotor system

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Good hovering stability (probably due pre-cone and stiff main rotor blades)

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Rigid undercarriage - limited vertical decent G absorption

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The possibility of not reaching full pedal in an emergency situation as the heel of a shoe could get caught on a lip in the floor close to the pedals (this happened to me and was another interesting unforgettable moment)

 

What would you do if the cyclic jammed in flight? or - if the cyclic control cables were connected in reverse

See part two for what we did when the swash plate uniball jammed in flight - in a turn close to the ground and the other incident with the crossed cyclic controls

 TC

Want to contribute your stories either anonymously or otherwise? Why not send me e-mail ! Your privacy will be respected - your contribution welcomed.

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