My OshKosh Prop Strike

So, there I was taxiing into HBC at OshKosh.....

My Engine was hot and surging from sitting on the taxiway as the orange vested scooter marshal turned into the grass at HBC. The scooter marshal got a little ahead of me about 75 yards, hopped off the scooter and stood at the front of my parking spot. Usually it's a 90 degree turn to park, but because of a soft spot in the row behind they were directing airplanes in front of the parking row requiring a 270 degree turn to park.

I didn't want to blast the airplanes around me trying to make the big turn into parking so I started an early shallow turn into the open grassy area and "KaThump!" I saw a flash of blue and saw this go flying out of the corner of my eye.


It made me kinda sick to my stomach as I pulled the mixture to idle cut-off. Initial inspection of the prop showed 2 blades of the Catto 3 blade caught the cone, a little melted blue plastic on the nickel leading edges and some hairline scratches or cracks aft of the nickel leading edge.


Thankfully I recognized an airplane/trusted A&P from VAF camping just down the row from me. Thank You Walt of ExpAircraft for your time, expertise and advice.

It seemed the prop was OK, just surface scratches. I made my first leg after leaving OSH 30 minutes to inspect to prop and do breakfast. No issues on the remaining 3 hours home. I was in contact with Catto at OSH and plan on keeping an even closer eye on the prop.

I'm going to be down right paranoid about taxiing, especially in open areas from now on. Stay weary and fly safe.

No good deed . . . as the saying goes. That thing could have been camo!

What did Craig Cato say about the cracked paint? Does the substate flex that much without permeant damage?

saw it happen...

I was sitting in front of my cowling in the next row back and yelled out as the marshall drove you right into the cone. Don't beat yourself up... the next row back was fine there were no soft spots. The scooter guide got way ahead and whipped into the next row expecting you to follow. He did not realize that he drove you right into the cones though. One of those things to note and learn from. Very happy that the cone was soft and your prop is doing good.

Bill, no reply from Catto yet. I'm sure they're busy returning from OSH etc.

Thanks Stephen.

My turn

In HBC, site 308. Thurs AM early like 615 am, I was at the showers, and a high wing pulled out of my row and taxied to p1 for departure. My friend actually saw his wing HIT my prop and turn it.

No kidding. I was the second last plane before p1 taxiway, and its was just bizarre. The guy must have been prepping to turn from the grass row onto the taxi way ...and moved over like he was driving a big rig as my plane was actually further back in line than the others.

So if anyone knows a red high wing that was just down from site 308 in amongst all us +rvs...that taxied out thurs am..... he owes me at least an apology.

My buddy was so surprised....that he wanted to tell me what happened and didnt bother to get the tail number. There are very small chips on two of the tips...and red paint transferred..but no real damage... Amazing, and kind of sucks. Could have been worse i suppose.

How's that mag behaving Rick?

Awesome

Running like new sir. Thanks for the pro help. Purrs like a kitten.

Life is back to awesome! I get so bummed when bird is off line.

I had a similar experience. On Monday after landing on RWY27 after the airshow I exited per instructed to the right side of the runway. Was directed to proceed west on the grass taxiway and was watching the ground marshaller beckoning me to "come on" toward the west. Soon I caught something out of the edge of my vision to the right and saw a sign collapsing under my right wingtip.

This was the sign that told one to "keep left" on the two way taxiway.

I never saw the sign because I was concentrating in the marshaller. I taxied up to the next intersection where a marshal came over to tell me I had hit the sign with my prop but that they were designed to give way. Then I was told to reverse direction and proceed east to the Alpha taxiway crossing near the threshold of RWY27 for a shorter taxi to HBC. Big mistake but that is for another time.

Bottom line I made it to parking and examined everything. Saw no evidence of a prop strike and no ever a scratch on the wingtip paint where I knocked the sign over.

All points to need as PIC to be wary when following taxi instructions in the grass. The marshals tend to stand far to the side of the taxiway as beckoning one forward and if you take aim for them (particularly if at a distance) you will tend to drift across the centerline of the taxiway area in the grass which was the root cause of my mistake. It would have been nice if the marshaller had been paying closer attention and given me a stop sign before I taxied into the sign but, as PIC it was all on me.

Having said that I don't know why they were insisting on exiting RWY 27 to the right for all arrivals as it led to the need for a horrendous taxi to get to HBC. I ran into the FAA Ground Controller who happened to be working the Alpha crossing that afternoon and they indicated it as an EAA and not an FAA direction that caused all traffic to exit to the right.

In the end I was lucky or I could have damaged my prop or worse.

I'm not sure it's a good idea to put these in writing. If your prop hits "anything but air" while running, a prop strike inspection is required.

That is a little too broad

This is the language from Lycoming on prop strike inspection requirements:

A propeller strike includes:
? Any incident, whether or not the engine is operating, where repair of the propeller is necessary
? Any incident during engine operation where the propeller has impact on a solid object which causes a decrease in RPM and also makes a structural repair of the propeller necessary. This incident includes propeller strikes against the ground. Although the propeller can continue to rotate, damage to the engine can occur, possibly with progression to engine failure
? Sudden RPM drop on impact to water, tall grass, or similar yielding medium where propeller damage does not usually occur

I would be concerned if Catto thinks that prop needs removal (ie not just cosmetic) for repair. But "anything but air" is too conservative.

Jesse said:

I'm not sure it's a good idea to put these in writing. If your prop hits "anything but air" while running, a prop strike inspection is required.

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I had a similar "strike". My prop hit a wooden runway marker however. Like yours I had tip damage. Mine looked much worse than yours. I sent the prop back to Catto mostly because there was a nickel leading edge defect from installation. Ended up that the tip damage was just paint. He had to replace my nickel leading edge and repaired the tip for free. I'd say yours is mostly cosmetic.

Glad to hear everything appears to be ok with the prop. I saw it happen and my heart sank with yours when it happened. You came over a couple days later and we chatted a bit so I just wanted to shout out and say hi again and glad you posted an update on the topic.

blahphish said:

Glad to hear everything appears to be ok with the prop. I saw it happen and my heart sank with yours when it happened. You came over a couple days later and we chatted a bit so I just wanted to shout out and say hi again and glad you posted an update on the topic.

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Thanks Brian, It was great to meet you and your family and hear about your trips.

Catto reviewed my photos and wanted a tap test of the nickel leading edge to check for any de-lamination, If no de-lamination is found there is no need to send the prop in.

Walt gave my prop a thorough tap test before I left OshKosh and no signs of de-lamination were found. I also checked the prop tracking prior to leaving OshKosh and found everything straight. This morning I checked the prop bolts for torque and did another tap test on the prop blades. So far everything looks good.

crabandy said:

Catto reviewed my photos and wanted a tap test of the nickel leading edge to check for any de-lamination, If no de-lamination is found there is no need to send the prop in.

Walt gave my prop a thorough tap test before I left OshKosh and no signs of de-lamination were found. I also checked the prop tracking prior to leaving OshKosh and found everything straight. This morning I checked the prop bolts for torque and did another tap test on the prop blades. So far everything looks good.

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Glad to hear it was not any structural damage. I have the composite Hartzell, so learning the tap sound is in my future.

Prop Strike by another plane

After a friend's RV suffered a hit and run prop strike by a high wing plane, I always make it a point as I am chocking, walking around etc to turn my prop to the 3-9 o'clock position...it has worked so far

dabney said:

After a friend's RV suffered a hit and run prop strike by a high wing plane, I always make it a point as I am chocking, walking around etc to turn my prop to the 3-9 o'clock position...it has worked so far

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I have always positioned my prop at 6-12 o'clock position, especially while at air shows, since it is a wood prop and I don't want people walking into the tips. I have a friend who several years ago while at Oshkosh had the tip of his prop damaged by someone walking into it.

I guess you can't second guess where the damage might come from.

Andy, Glad to hear that it appears the damage you have is only cosmetic.

Funny

dabney said:

After a friend's RV suffered a hit and run prop strike by a high wing plane, I always make it a point as I am chocking, walking around etc to turn my prop to the 3-9 o'clock position...it has worked so far

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I have a three blade. I usually like the one blade straight up high and the two lower split at the bottom in a y, but to hang the eaa sign on, i turned it to 2/10 so one blade was straight down at 6....it was as low as a three blade goes and the idea of high wing taxing into my plane was not even a thought. Its was literately 1/32 of an inch contact....just enough to slow motion turn blade a bit and leave transfer.

I have thought of finding pics of the planes in the row and getting tail number but the dude didnt do it on purpose...and its possible isnt even aware.

curtis said:

I have always positioned my prop at 6-12 o'clock position, especially while at air shows, since it is a wood prop and I don't want people walking into the tips.

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This might be OK for short periods, but normally a wood prop should always be left in the horizontal position. Wood has a lot of moisture content and leaving the prop vertical causes the moisture to migrate toward the lower tip throwing the prop out of balance.

Mel said:

This might be OK for short periods, but normally a wood prop should always be left in the horizontal position. Wood has a lot of moisture content and leaving the prop vertical causes the moisture to migrate toward the lower tip throwing the prop out of balance.

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I just learned something today! thanks Mel.

Mel said:

This might be OK for short periods, but normally a wood prop should always be left in the horizontal position. Wood has a lot of moisture content and leaving the prop vertical causes the moisture to migrate toward the lower tip throwing the prop out of balance.

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bret said:

I just learned something today! thanks Mel.

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I learned this while doing a little flying in a wooden bladed Bell 47 and an old Hiller. Leave one on those tied down for very long with the rotors tilted and it can get your attention! A couple of old hands at my airfield made sure to remind me that it matters on these little props as well!

Directed into a Hole

While being directed to a grass parking spot at Whiteplains (SC99) during South Carolina Breakfast Club this year I inadvertently found a hole with my nose wheel. The cut grass over the hole was the same height as the surrounding grass so the ground appeared level. Luckily, no prop strike, but did tear up the wheel pant. I am about to refuse to park anywhere but solid surfaces in the future.

The grass and clover was so high in HBC that I had green stains on the very tips of my prop after parking! In almost 200 hrs, that's a first even after half a dozen grass landings. Nothing like hitting a solid object but gets you thinking!

Mel said:

This might be OK for short periods, but normally a wood prop should always be left in the horizontal position. Wood has a lot of moisture content and leaving the prop vertical causes the moisture to migrate toward the lower tip throwing the prop out of balance.

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Good evening Mel,
I firmly believe that with the finishes on todays propellers, the position of the prop will have no appreciable effect on balance when the engine is ran on a regular basis. This is true as long as the finish is good and the plane lives inside of a hangar. I agree that all wood has a moisture content, but if there was enough moisture inside of the prop to migrate then it would be physically impossible to keep a three bladed prop balanced. I have almost 5 years and over 500 hours on my prop and do not have any issues with balance.
I did learn in A&P school about how to position a prop, but keeping in mind that was put into the text books when when props had brass leading edges and drain holes in the metal leading edge.

I am not trying to start a big argument on this subject, especially in the current thread and I do respect your opinion and knowledge.

Curtis