In-Flight Prop Failure
 

Hello everyone,

I would like to get the word out to everyone that I had an in-flight propeller blade failure on 9/18/10. It happened 1/2 mile south of a friend?s private strip so I was able to make a safe landing. No damage from the landing but quite a lot from the loss of the prop blades.

This was my 2nd flight with my DAR sign-off that morning. RV-4, 0320 D2J 160HP with a props Inc., 68" ground adjustable wooden propeller.

Conditions: 1.9 hours service life at time of failure, 1400MSL, 2300 RPM. It happened with no warning. I had just reduced power to slowly start CYL head cool down and I heard a loud snap, followed by heavy vibration for a mille-second and then bang!, the prop disappeared.

Damage: Propeller blades no longer exist but all hardware remains. Most of the spinner is even intact with damage to the blade root area. The cowling has multiple spots where the gel-coat cracked and a crack by one exhaust stack. The exhaust system is destroyed and the engine mounts have funny brown powder on them (I suspect it smoked the rubber). Most engine shops recommend that I tear the engine down for inspection. I majored it myself and am capable of doing the work but what a bummer!

I have a new 4-pipe system ordered from Larry and a new fixed pitch prop ordered from Craig Catto. I will repair the cowling.

I know I am very lucky for several reasons but after assessing the damage and work that it will take to get it airworthy again, it's hard to feel lucky.

I have reported this to the FAA and NTSB as required. They were pleasant to deal with. I am on hold with my insurance agent now to see if they will cover this incident.

If you know anyone that has a Props Inc. ground adjustable propeller, please pass this information along.

I would like to hear from anyone regarding advice about the engine. I am leaning toward a complete teardown to send the crank out for inspection (again).

Tim,

I do not have any advice on the engine rebuild but I want to say I am glad to hear you are OK.

Thanks Steve.

Wow!
 

So sorry to hear this. Just really glad that you're ok. I'd be very tempted to run the whole scenario by Lycoming before I'd start any disassembly, though.

Probably an IA or two will have better knowledge as well.,

Best,

Tim,
My opinion is that you should do a complete engine tear-down looking particularly at the internal front of the crankcase and crankshaft, including the bolt and pin attaching the gear at the aft end. This kind of "shock" can easily damage these components.

Glad you are okay.

Good job staying focused and calm enough to land the plane with no prop! Well Done!

Have you talked to the prop company? Any ideas as to what happened or why?

Wow.

I'm pretty sure this recent Oklahoma RV8 incident also involved a failed Props Inc ground-adjustable:

http://www.ntsb.gov/ntsb/brief.asp?e...07X00918&key=1

Catto Propellers
 

Hi Tim
First of all it great to be writing this to you! It could have been a much worst.
You had to of done a good job of putting your wounded bird down after your prop departed Great Job!!
I have had a Catto prop for three years now and I couldn?t be happier with the performance and customer service. I think it?s a good choice for the RV-4

Since you asked........
 

Here is my take on this, tear it down, and inspect everything with magnaflux and zyglow as needed.

You mentioned a short period of heavy vibration-----this is where the damage, if any will probably have occurred.

The effect of high frequency low amplitude impact is pretty impressive ....... think of an air chisel, or an impact wrench, or what an A10 does to a tank. One hit from any of the above is pretty much of a non event, but a lot of them in quick succession ...............

As Stein says, my $0.02

This is the second or third reference I've seen in the last year to ground-adjustable prop failures.