Lucky escape

[barney]

Your heli suffered some severe vibes so things to check.

High frequency Vibes.

If it's a tingling type vibration at idle suspect the following Mixture, Motor rear bearing (does it knock at Idle?) or Clutch cracked (rattle and clonking) Clutch or Startshaft out of balance/alignment.

Rotor disc wobbling, poor tracking low resonance vibes.

Head Checks the quick way. First Check your Dampners then do a Static tracking check. To check the Spindle remove one blade. Park heli on a flat surface close to a wall or similiar. With Main blade dead straight out turn Radio on and set Pitch to 0. Hold Flybar horozontal and Mark the wall where the blade tip passes and Turn the Spindle 360 deg with an Allen Key..Blade tip should remain still. Repeat for opposite Side.

Main shaft check as above but with both blades fitted Blade tips should pass within a couple MM.

Gyro wagging, loose boom stay, the ends tend to pull out of the alloy ends, pull boom very firmly side to side also look carefully at them all + the boom clamp. Gyro tape Mount going bad. Wiring or anything moving around up front.

Check your tail shaft is not bent, spool it up and eyeball the tail blade tips are in alignment. Usually an up down high frequency vibe on the tail fins. torque tube bearing shifted but normally only apparent at higher RPM,s need to pull the tail gearbox to check that one out. Front TT geartset missing a tooth or not meshed.

Phew I think that gets most of the possibles..

[HAWK 30]

Your heli suffered some severe vibes so things to check.

High frequency Vibes.

If it's a tingling type vibration at idle suspect the following Mixture, Motor rear bearing (does it knock at Idle?) or Clutch cracked (rattle and clonking) Clutch or Startshaft out of balance/alignment.

Rotor disc wobbling, poor tracking low resonance vibes.

Head Checks the quick way. First Check your Dampners then do a Static tracking check. To check the Spindle remove one blade. Park heli on a flat surface close to a wall or similiar. With Main blade dead straight out turn Radio on and set Pitch to 0. Hold Flybar horozontal and Mark the wall where the blade tip passes and Turn the Spindle 360 deg with an Allen Key..Blade tip should remain still. Repeat for opposite Side.

Main shaft check as above but with both blades fitted Blade tips should pass within a couple MM.

Gyro wagging, loose boom stay, the ends tend to pull out of the alloy ends, pull boom very firmly side to side also look carefully at them all + the boom clamp. Gyro tape Mount going bad. Wiring or anything moving around up front.

Check your tail shaft is not bent, spool it up and eyeball the tail blade tips are in alignment. Usually an up down high frequency vibe on the tail fins. torque tube bearing shifted but normally only apparent at higher RPM,s need to pull the tail gearbox to check that one out. Front TT geartset missing a tooth or not meshed.

Phew I think that gets most of the possibles..

Thanks for all the above, will start tomorrow night.

Regards
A

[HAWK 30]

Thanks Guys

Had the Engine bearings replaced by Dave (Thanks Dave :-) Hoping it will solve the problem of a waggling tale. New blades installed and I still have a waggling tail !
The bearings feel a bit gritty ! (not right) and the end bearing is heavily stained, the engine has never been run lean, if anything its on the rich side..
http://i590.photobucket.com/albums/s...earings002.jpg

http://i590.photobucket.com/albums/s...earings003.jpg

I have just replaced the main shaft and the feathering spindle and dampeners, with a bit of luck that will solve the problem. Can't wait for tomorrow :-)

Regards

Z

[Brian Gifford]

Your heli suffered some severe vibes so things to check.

High frequency Vibes.

If it's a tingling type vibration at idle suspect the following Mixture, Motor rear bearing (does it knock at Idle?) or Clutch cracked (rattle and clonking) Clutch or Startshaft out of balance/alignment.

Rotor disc wobbling, poor tracking low resonance vibes.

Head Checks the quick way. First Check your Dampners then do a Static tracking check. To check the Spindle remove one blade. Park heli on a flat surface close to a wall or similiar. With Main blade dead straight out turn Radio on and set Pitch to 0. Hold Flybar horozontal and Mark the wall where the blade tip passes and Turn the Spindle 360 deg with an Allen Key..Blade tip should remain still. Repeat for opposite Side.

Main shaft check as above but with both blades fitted Blade tips should pass within a couple MM.

Gyro wagging, loose boom stay, the ends tend to pull out of the alloy ends, pull boom very firmly side to side also look carefully at them all + the boom clamp. Gyro tape Mount going bad. Wiring or anything moving around up front.

Check your tail shaft is not bent, spool it up and eyeball the tail blade tips are in alignment. Usually an up down high frequency vibe on the tail fins. torque tube bearing shifted but normally only apparent at higher RPM,s need to pull the tail gearbox to check that one out. Front TT geartset missing a tooth or not meshed.

Phew I think that gets most of the possibles..

Just seen this, Brian. Nice fault-finding guide - Going into my WTF is wrong folder.

Thanks.