UH-1N
Heliman
Location: New Hampshire
My Posts This: Topic Forum | Hi McKracken and All,
When I was in the service I was a Huey (UH-1H) Crew chief. If you want scary, let me tell you how we tracked the main and tail rotor.
Tail Rotor -- duck tape 6" of rubber water hose to the end of a 4foot long broom stick. Then duck tape a grease pencil to the 6" water hose. Get the Pilot in the bird and run it up to medium idle holding everything steady. The Crew chief (me) approaches the tail on the right side (blades are on left side). Using the tail boom as a guide, slowly feed the grease pencil assembly into the spinning tail rotor. After shutdown, look at the blades and make the adjustment. Run it up again and repeat until you get grease pencil marks on both blades. This actually was a pretty easy, fast and effective way to get it done.
Main Rotor -- this is the scary part. We had a ~20 pole. At the top was two perpendicular rods that stuck out about a foot long and about 2 feet apart (picture a 20foot tall letter 'F' ). Next we ran duck tape between the two top 1 foot rods. (Picture the 20 foot tall letter 'F' with the top filled in to look like a small flag). Next we would go to each end of the main rotor blades, the main blades had a bracket screwed to each end with a hole in it so that we could hook into it to tie it down when parked on the ramp. These brackets stuck out from the end of each blade, we would color each bracket end with a grease pencil, one Black and one Red. Next, get the Pilot in the bird and run it up to medium idle holding everything steady. Two Crew chiefs would raise the flag and then, very slowly approach the main rotor disk (always in front so the pilot could shut down in case of a screw-up). This is the part that never got comfortable, ease the flag into the end of the spinning main rotor disk, just so it touches, then back away and lower the flag. Take a look to see which color is out of track, after shut-down, adjust the main rotor links and repeat until both marks are in track.
Ah the good ole days... I survived them!!
When I left the military, they were using a "Vibrex System", a strobe with reflectors mounted on the blades, it was a safer method, but took a lot longer....
Happy flying!!
Dave |
