Post Flight Inspection Cards

[Goldy]

Yes, but that only addresses an engine overspeed, which usually occurs when on the ground, especially start up with Gov off.

 

Most of the overspeeds I have seen involve the main rotor, and all were done during auto's where the engine speed was at idle.

 

Nothing will tell you that the main rotor was oversped, not until some time later. All will look and feel normal, and gradually you will begin to notice several things.

 

1. Lack of forward speed. Often times I have seen when mechanics "fix" this by putting in a new, stronger bungie cord on the cyclic. So much so when the ship is sitting on the ground, the cyclic is pulled into the instrument panel.

 

2. Cyclic stirs on the ground. Just start to move it and the stick will take off on its own in a circle pattern.

 

3. Increased vibration in the main rotor, can't fix it by balancing it. It might be better with a balance, but then a few hours later its the same old shaky ship.

 

I have flown several ships after an overspeed and I noticed each of the 3 issues above each time. Once oversped, the spindle bearings wear fast, and you can really tell after 20 hours of additional flight or so.

 

Fly safe, fly it in the green!

 

Goldy

[ADRidge]

Damn, Goldy. I'm thinking back to the R-44 I used for all my instrument training, and it exhibited all those symptoms. Awesome.

 

Good stuff to know.

[Goldy]

Damn, Goldy. I'm thinking back to the R-44 I used for all my instrument training, and it exhibited all those symptoms. Awesome.

 

Good stuff to know.

 

Aren't you glad you found out now?

[RkyMtnHI]

I am told that you can also feel it in the collective when you pull pitch (MR over-speed), i have not experienced this as all of the over-speeds that i am familiar with were engine related. The collective will pulsate (i can't remember the terminology) when you pull or lower.

 

I took photos of one OS, i am still trying to find them (i have about 25K photos on my hard drive).

 

dp

[ADRidge]

Aren't you glad you found out now?

 

 

Haha, now that I have 74 hours in it and have moved on....

[RkyMtnHI]

Sorry this took me so long to get back to..

 

here is our post flight card for the R44.. we sold all the ones for the 300 and have to make some more, i'll add it when i can..

 

this wasn't so much about covering every aspect, but, to get the pilots in training to DO post flight inspections!!

 

thanks for all of your help folks, and anyone that wants to can copy and use the format or improve upon it!!

 

aloha,

 

dp

[naflight]

Part of the flight training environment is the fact that many people will fly these machines in all types of training maneuvers. That in itself should lend every pilot to a thorough pre-flight and for every student and instructor a proper post-flight.

 

What to look for on a post-flight? Well that depends on the machine and what you were doing. In some cases when you're running a 135 operation your post-flight may consist of any and all items that would "ground" your next flight...almost a complete run-up. Mag checks, warning lights, etc.

 

For a student/CFI the post-flight should contain at a minimum the "problem areas" in the helicopter which are dictated by the type of helicopter you fly.

 

For the R-22 our post-flights include the basics - look at the airframe, check fasteners, fuel leaks, oil leaks, etc. As part of our daily routines, every machine is "spot cleaned" by each instructor using a mixture of mild dish detergent and water at the end of the day. This allows us to determine the health of the machine and keep everything extremely clean. We get under the machine and inspect everything possible and clean every little drop of oil or grime. A great way to become familiar with anything that may one day be out of place.

 

As for overspeeds, as mentioned, the fan nut is a good way to tell if the engine has been oversped. But the best way to tell is to have a policy with all pilots that every overspeed has to be reported and limit the consequences except for repeat offenders - especially for your CFI's. If the consequences are too harsh guess what - no one will report an overspeed.

 

As for the rotor overspeeds, we have an overhaul shop here and you would not believe some of the blades that come in. The way to detect an overspeed is to feel the movement of the bearings. They should be smooth - when they're "notchy" that means they were abused. Probably multiple times. The centrifugal force of an overspeed causes the bearings to take a tremendous load.

 

When you're flying the R22 it's harder to tell, but usually it's a pronounced "hop" which cannot be balanced out. I'm also told that you can sometimes feel it in the collective, but I don't have experience with that one.

 

Be sure to read the Lycoming service bulletin on Engine overspeeds for the details on the engine overspeed and what constitutes each type of overspeed - it's interesting. Contains information for helicopters and fixed wing.

 

If you're doing training in an R22 it's highly likely that an overspeed of some type will occur. Having a formal policy for reporting and a consistent set of guidelines for inspections helps to find out when an overspeed happens.

 

If anyone would like a bearing from a set of blades that has been through an overspeed, let me know.

 

Curt