Stall strip for FIKI wing

[Roger M]

Stall strip is aluminum 12" long. Triangular about 1/2" deep. FIKI takes 2 glue on (no screw holes) strips per wing. I need one to replace lost strip. What adhesive do I need

 

[mike_elliott]

ouch, those titanium stall strips are 

1) hard to come by

2) expensive

3) did I mention they cost a lot?

 

[CAV Ice]

@Roger M I sent you a PM

[LANCECASPER]

On 5/5/2023 at 2:19 PM, Roger M said:

Stall strip is aluminum 12" long. Triangular about 1/2" deep. FIKI takes 2 glue on (no screw holes) strips per wing. I need one to replace lost strip. What adhesive do I need

 

Once you have paid to replace one, you see the need to include checking them as part of every pre-flight. 

[Fly Boomer]

On 5/5/2023 at 3:13 PM, CAV Ice said:

@Roger M I sent you a PM

The Mooney community (coMoonity?) is lucky to have CAV monitoring MooneySpace.

[larryb]

I learned right here on MS that these can come loose and replacement was expensive. So every flight I check them. Sure enough one day one was loose, so I ordered the proper adhesive, and re-glued it. A total non-event due to learning from others. 

[carusoam]

Go CAV Ice!

Go MS!

Go whole CoMoonity!  

-a-

[alextstone]

I had one come partially loose while out on a trip to Telluride.  I taped it with painters tape and flew home before addressing a fix for it.  

[ilovecornfields]

1 hour ago, alextstone said:

I had one come partially loose while out on a trip to Telluride.  I taped it with painters tape and flew home before addressing a fix for it.  

Is it airworthy if you tape over the stall strip?

[Niko182]

how much do they cost?

[Fly Boomer]

1 minute ago, Niko182 said:

how much do they cost?

Thousands.

[alextstone]

31 minutes ago, ilovecornfields said:

Is it airworthy if you tape over the stall strip?

Hmm, by airworthy do you mean, "Would it fly safely"? or "What would the FAA say'?

The answer to 1 is : in my opinion, yes

The answer to 2 is : Not sure about that.  The strip was still attached.  The tape held it firmly.  Therefore, all parts were still present and in place.  Technically, I suppose a ferry permit might have been in order but that's not what I chose to do.

[ilovecornfields]

1 hour ago, alextstone said:

Hmm, by airworthy do you mean, "Would it fly safely"? or "What would the FAA say'?

The answer to 1 is : in my opinion, yes

The answer to 2 is : Not sure about that.  The strip was still attached.  The tape held it firmly.  Therefore, all parts were still present and in place.  Technically, I suppose a ferry permit might have been in order but that's not what I chose to do.

You mean hypothetically speaking, of course. ;-)

The MSC in Troutdale caught a loose TKS stall strip during an annual a few years ago. Gluing it was probably the best bang for my buck I’ll ever get in general aviation. 

[geoffb]

I just did one, I think the price was about $1,600.  Worst part is dealing with the polysufide.  I've gone and reapplied all 4 now.  Trying to get a good, smooth external bead AND get them taped down firm to cure has been a real mess for me.  Also, done both pairs at cool ambient temps and even the 1/2 hour pot life adhesive takes forever to cure with temps in the 40s.

[mike_elliott]

Now go stall the plane and see if they are all in the right positions. 

[aviatoreb]

On 5/5/2023 at 3:22 PM, mike_elliott said:

ouch, those titanium stall strips are 

1) hard to come by

2) expensive

3) did I mention they cost a lot?

 

I lost one in Lake Michigan once... I bet its still there.

[mike_elliott]

Good thing is titanium doesn't rust!

[alextstone]

3 hours ago, ilovecornfields said:

You mean hypothetically speaking, of course. ;-)

The MSC in Troutdale caught a loose TKS stall strip during an annual a few years ago. Gluing it was probably the best bang for my buck I’ll ever get in general aviation. 

 

Yeah, hypothetically...and this photo was AI-generated ;-)

[DonMuncy]

It is my understanding that the factory tapes the stall strips in place, test flys to check the stall characteristics, moves them as necessary and ultimately fixes them in place. I wonder how critical the placement is. Does an 1/8 inch difference in placement make a big difference?

[mike_elliott]

Yup..

[Fly Boomer]

3 hours ago, mike_elliott said:

Now go stall the plane and see if they are all in the right positions. 

You fly many different airplanes.  Based on your experience, how far off (and in which direction) would it have to be to cause nasty stall characteristics?  And by "nasty" I mean 90-degree roll or more.

[GeeBee]

https://www.mooney.com/wp-content/uploads/2020/12/SBM20-322.pdf

As for why they come off, I've detected two contributors. One is water gets between the strip and the panel, freezes and lifts the strip off. A careful application of silver RTV (very thin strip and don't get it on the pores! I use a syringe and needle to apply) keeps the water from getting in behind the strip and lifting it off. The second modality is ramp people pushing on the strips and panels while ground handling the aircraft. That is why they have "DO NOT PUSH" placards. Even with the placards I am always stopping people from pushing on the leading edges. It will not only loosen the strips it can loosen the whole panel. Those rivets are not structural, they are anodes.

 

[mike_elliott]

12 hours ago, Fly Boomer said:

You fly many different airplanes.  Based on your experience, how far off (and in which direction) would it have to be to cause nasty stall characteristics?  And by "nasty" I mean 90-degree roll or more.

The idea is to have both wings stall at the same time when exposed to the same angle of attack and this is caused by making the stagnation point (where the air separates from going over the top and bottom of the wing) equalized on both sides. Since the wings are all "different" when installed, stall strips aid this adjustment. This is a fine adjustment made by the vertical placement at critical outboard stations on each side of the wing. A really out of rig or plane without any stall strips on one side can cause the ride you describe. Maybe Scott Sellmeyer or one of our other aeroengineers can chime in to the math of it and thus possibly give a dimension to the discussion above my pay grade

[Danb]

Good discussion at the Summit 

[mike_elliott]

1 hour ago, Danb said:

Good discussion at the Summit 

@exM20K, feel like doing an icing, fiki thing @ the summit? ping @DanM20C