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a prop question:


venom 66
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I have a question for the prop guys: as a crew chief, i was taught that when you feathered a prop,everything was shut off. hyd fluid,oil,elect,fuel, etc. A man by the name of Eric L Haney was a delta force operator and in his book,'inside delta force' he states that on that failed hostage rescue mission in iran in the middle of the desert in 1980, that the 130 he was on,'the engines continued to run,but the props were feathered'.All of my teaching says thats impossible. Or was he mistaken? Did they feather the props and he heard the GTC running? Would the crews even have shut down the eng's in that circumstance? Anyone know any extra info that they are allowed to share? thanx guys.

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I don't know the particular instance, but he most likely thought he knew what he was talking about but misstated it. I am not familiar with that book so did he say they feathered them in flight or on the ground?

The aircraft was on the ground. There were 5 other Herks + the Helos there that night all with engines running blowing sand, minum visability and the burning bus. I as a Talon pilot knowing this crew think they were initially momentary, stunned, surprised by the explosion and confused by what was happening to them. There was most likely a few seconds delay before deciding to shut down/feathering the engines. Also, it takes a few rotations before they actually feather. If I recall from the photos in the book "The Guts to Try" the props appear to be feathered. Just my 2 cents.

Edited by Skip Davenport
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It is impossible for those engines to keep running if feathered.. If you pull the fire handle all those valves you mentioned are shut off... When you pull the fire handle every thing is shut off electricly.. When you pull the condition lever the fuel is mechanically shut off, and the prop feathers and your other valves stays open... If the GTC was not running at the time of the feather the props would not have enough electric power to go all the way to feather ..

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The aircraft was on the ground. There were 5 other Herks + the Helos there that night all with engines running blowing sand, minum visability and the burning bus. I as a Talon pilot knowing this crew think they were initially momentary, stunned, surprised by the explosion and confused by what was happening to them. There was most likely a few seconds delay before deciding to shut down/feathering the engines. Also, it takes a few rotations before they actually feather. If I recall from the photos in the book "The Guts to Try" the props appear to be feathered. Just my 2 cents.

Ok I remember this now, I saw a documentary on the History channel about it.

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If the GTC was not running at the time of the feather the props would not have enough electric power to go all the way to feather ..

I don't believe this is true. I have seen on more than 1 occasion crew chiefs put on DC power to check fuel/lox etc and watched a prop go into feather. The DC system if charged should have plenty of power to throw the props into feather.

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battery bus tie

EDIT: The fire handle must be pulled for this to work. Let me do some research, I have been off work for 3 weeks because of the birth of our baby ;) My brain is fried.

Looks like to me that the DC bus will power the pump if the condition lever is left to feather. Am I looking at that wrong?

Edit: Another thing I found.

FUNCTIONS OF THE FIRE HANDLE

There are 9 things that happen when you pull an engine fire handle.  Remember BEEFF SHOP

1. Bleed air regulator closed. (ESS DC)

2. Extinguisher agent discharge switch is armed. (Battery)

3. Extinguisher system control valves positioned. (Battery)

4. Fuel shutoff valve at fuel control closed. (ESS DC)

5. Fuel shutoff valve at firewall closed. (ESS DC)

6. Start circuitry for engine de-energized. (ESS DC)

7. Hydraulic shutoff valves at firewall are closed. (ESS DC)

8. Oil shutoff valve below oil tank closes. (ESS DC)

9. Prop is Feathered. (ESS AC and ESS DC)

Edited by C130CC
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Nope, no Ess AC, no (true) feather.

Anything DC is just for the valves and relays, and there is no way to tie the inverter power into the aux feather motor.

If you shut down the engine inflight without the aux feather motor having power it may move toward feather if the blade angle is high enough but those throttles would have to really be up there. Also, even if your prop does move towards feather I am pretty sure there wouldn't be sufficient air pressure to engage the feather latches.

Dan

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We use to pull those breakers at the last flight of the day to shut the oil shut off valves on the E models this would keep the oil from flooding the turbine section.. The breakers was pulled to keep the prop from feathering while pulling the fire handle to shut the oil valve off... We did this if some one still had external, or gtc, power on..

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We use to pull those breakers at the last flight of the day to shut the oil shut off valves on the E models this would keep the oil from flooding the turbine section.. The breakers was pulled to keep the prop from feathering while pulling the fire handle to shut the oil valve off... We did this if some one still had external, or gtc, power on..

At the end of the flying day the way I closed the oil tank so valve was to pull the T handle with only DC power on the acft. This precluded unnecessarly exercising the prop feather motors. With the valve closed would then pull the oil tank so valve cbs. I did this for the most part so as to preclude having to service engine oil right away when I really wanted to get on with the post flight/recovery. However, as you say this also prevents oil from leaking into the power section if there is a leaky check valve, a not uncommon occurance. The best part was I could service eng. oil the next morning at my leisure after which would reset the so valve cbs. On more than one instance took grief from flt. line supervision when they saw me servicing oil knowing the bird had landed the previous evening.

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Don't think you could get to #2 before 3&4 locked up.

This FE should be shot, and the instructor that trained him with him!!!

RZ

A's used 3 phase ac to feather the prop also. Dc is the control , ac is the operator.

The crew chief should have reset the C/B's before the FE set foot on the aircraft!
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