Stall Strips

Stall Strips

Postby David Rounds » Tue Dec 11, 2012 3:54 am

Hi Gang,

Not sure if this is the right forum but here goes. Having had the twin co for a few months, It seems I notice more things with each pre-flight...things that give the aircraft character if you will. I found that I have a loose stall strip on the left wing which it appears should only require some new riveting. Upon checking the right wing, I noticed it has two stall strips (don't know how I missed this before now). I don't have the modification paperwork at hand but was curious #1 is that the normal install and #2 what's the purpose of having two strips on one side and only one on the other?

Thanks,

David
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Re: Stall Strips

Postby Kristin Winter » Tue Dec 11, 2012 5:47 am

That is normal for aircraft that have had the airflow modification kit installed. I am not sure why there are two on the right side, though I am guessing it has to due with the different airflow as the downward blade is on the outboard side of the nacelle there.
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Re: Stall Strips

Postby N3322G » Tue Dec 11, 2012 1:38 pm

Hi David,

Welcome to the Forum and twin ownership.

Had to laugh in empathy about things you notice. I'm 42 years around the same twin, second generation owner, and still I have to go verify stuff at times. I'm pretty sure my PA39 twin has 2 right and one left like yours but I'll go look today and make sure. I haven't had to write a check or replace them so it is just memory of washing around them that makes me think 2 and 1.

The later Twins came from the factory with the strips. I looked up your twin on pathfinder and noticed it was a PA30C so it likely came from Piper that way. PA30C and PA39 were essentially same generation and my 39 has the two on the right and one on the left
Pat

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Re: Stall Strips

Postby Zach Grant L1011jock » Tue Dec 11, 2012 2:15 pm

The C/R should have symetrical stall strips, and the non C/R should have assymetrical strips (some airplanes that were converted to C/R incorrectly still have assymetrical strips as well). I have noticed there are some airplanes out there with some very creative installations. Among other things, Im not sure where the installer was measuring from as the spanwise distribution seems to vary five feet or more on some of these.
"Keep it above 5 feet and don't do nuthin dumb!"
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Re: Stall Strips

Postby bernard nowlen » Tue Dec 11, 2012 4:48 pm

The right wing on my 67 twinco has 2 stall strips do to the airflow mod kit. I went out the other day and did some power off stalls and the right wing stalls and drops first. I think this goes back to the old days when folks were doing VMC demo's and inducing a left roll/spin if they stalled. Back in 1964 i was observing a VMC demo from the back seat of a twinco and the instructor turned off the fuel on the left engine while in slow flight( below VMC). When the left engine quit the student applied full throttle to the right engine and we were upside down in a nano second at 1000 ft agl. All i saw was a windshield full of trees. The IP was ex airforce and was able to close both throttles, clean up the plane, and continue the left roll untill we were straight and level. I don't think he expected this to happen and we called it a day.
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Re: Stall Strips

Postby N3322G » Tue Dec 11, 2012 5:50 pm

At annual at Clifton so it was easy to look today.

My 39 has one on each side at mid-wing. The right one has a rivet in the middle and the left one has the stall warning in the middle.

Last week there was another PA30 here and it had two on the right and one on the left so I was thinking about the wrong twin.

Rented a 39 a few years back and it had zero stall strips. It previously had deicing equip and when it was removed the stall strips were not there or not replaced.
Pat

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Re: Stall Strips

Postby SLIMDREDGER » Tue Dec 11, 2012 7:40 pm

One more data point: My PA30 C/R with the Robertson Mod has NO stall strips. Al Powers ICS 2978
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Re: Stall Strips

Postby David Rounds » Tue Dec 11, 2012 9:52 pm

Thanks for all the replies. Glad it's not an anomally. Still learning all the in's and out's of the aircraft. Looking forward to attending a CPPP in the new year.

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Re: Stall Strips

Postby N3322G » Wed Dec 12, 2012 4:54 am

CPPP is a great experience !
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