Grumman kit

Since it's already at a top Grumman shop, I wonder how much to "complete" the project and restore to air worthy?
 
As for speed, it's good for about 142 KTAS in 70% cruise and around 154 KTAS top speed on the deck. And yes, the climb rate is very good -- much better than a stock Tiger.

If you want 200mph, you'll have to go with Fred Kokaska's "Sabertooth" conversion with a 260HP IO-540, but I don't think that STC is publicly available and Fred died last year.
 
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There is one of those at the home drome, I imagine it is fun, but not sure the fuel burn would be worth it on that airframe
 
Ron Levy said:
As for speed, it's good for about 142 KTAS in 70% cruise and around 154 KTAS top speed on the deck. And yes, the climb rate is very good -- much better than a stock Tiger.

If you want 200mph, you'll have to go with Fred Kokaska's "Sabertooth" conversion with a 260HP IO-540, but I don't think that STC is publicly available and Fred died last year.
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That would seem to be near perfection...

Skylane81E said:
There is one of those at the home drome, I imagine it is fun, but not sure the fuel burn would be worth it on that airframe
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I'd expect that, at equivalent speeds, there would be a reasonable chance of burning less, not more, fuel.
 
SCCutler said:
That would seem to be near perfection...



I'd expect that, at equivalent speeds, there would be a reasonable chance of burning less, not more, fuel.
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The high compression C1C engine likely is, the big 540 is likely not going to be operating at its most efficient power settings to go as "slow" as the factory plane
 
AggieMike88 said:
Since it's already at a top Grumman shop, I wonder how much to "complete" the project and restore to air worthy?
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Top Grumman shop? Let's hope they did not write the ad.
 
Skylane81E said:
The high compression C1C engine likely is, the big 540 is likely not going to be operating at its most efficient power settings to go as "slow" as the factory plane
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Yeah, that. I meant the 200hp, but (of course) did not write that.
 
Ron Levy said:
As for speed, it's good for about 142 KTAS in 70% cruise and around 154 KTAS top speed on the deck. And yes, the climb rate is very good -- much better than a stock Tiger.

If you want 200mph, you'll have to go with Fred Kokaska's "Sabertooth" conversion with a 260HP IO-540, but I don't think that STC is publicly available and Fred died last year.
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Has any one investigated the possibility that his heirs would issue the STC?

They would now own it, would they not?

What would you think would be a fare selling price in this market? (flying that is).
 
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Nothing screams the 70's better than brown and orange. :lol:
 
wabower said:
Who cares? They're not fixing it, they're selling it. Caveat emptor
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who ever wrote the ad is suggesting how it can be repaired.

I hope it was not the "Top Grumman" shop
 
SCCutler said:
I'd expect that, at equivalent speeds, there would be a reasonable chance of burning less, not more, fuel.
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I didn't really look hard at that when I test-flew the HyperCheetah, but I doubt the difference will be significant, and probably on a par with the increase in maintenance costs due to the fuel injection and c/s prop. This is not a mod you get to save money.
 
Tom-D said:
Has any one investigated the possibility that his heirs would issue the STC?

They would now own it, would they not?
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As I said, Fred never owned the STC -- he developed it for Peter Otten, and Peter sold it to Fletchair who sold it to Hyperdyne, the current holder.

What would you think would be a fare selling price in this market? (flying that is).
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I wouldn't hazard a guess other than to say maybe $10-15K or so more than the same plane with a stock Tiger propulsion system, based on the market differential between stock Cheetahs and stock Tigers.
 
Tom-D said:
either way, is that a proper fix?
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I know a lot of highly reputable paint shops which fill dents/dings with bondo during paint jobs when there is no cracking or the like. As that work has always been signed off by an A&P, I've always assumed it was legitimate.
 
AggieMike88 said:
Since it's already at a top Grumman shop, I wonder how much to "complete" the project and restore to air worthy?
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Seems like a reasonable statement. And they do not mention Bondo, they mention filler. And they show what looks like hangar rash on the right wing. I know little about Grummans and have no dog in this fight; the below is from the web.

http://www.fletchair.com/

FletchAir, Inc. is known worldwide as the single largest manufacturer and distributor of parts for American, American General, Grumman-American, and Gulfstream-American aircraft. David Fletcher, President of FletchAir, has grown up with the Grumman family of aircraft and has been a stocking Grumman dealer since 1974.

Fletcher has dealt exclusively with Grumman aircraft and their parts for over 30 years.

FletchAir keeps a full set of drawings and has access to most tooling. We can build nearly any part on the airplane and provide PMA authorization. FletchAir purchases retired aircraft for parts to supplement our new parts inventory, enhancing our ability to satisfy our customer’s needs. We have parted out over 90 damaged Grumman-Americans and have almost every commonly used part available in our used parts inventory. This inventory constantly changes and would be impossible to publish. Please call us with your needs and see what we have in stock currently. Your parts will be shipped immediately.

FletchAir Fleet Support LLC provides maintenance, modifications, and repairs to all the Grumman family of aircraft, from the AA-1 to the twin Cougar. Located in Houston, Texas for 32 years, FletchAir Fleet Support is now located at Silver Wings Fly-in Ranch 1409 Aviation Loop, Fredericksburg, Texas 78624 (TS36). If your aircraft is in need of maintenance and/or parts, our experienced staff is here to promptly serve you. We are labeled the “Grumman Specialists” with David Fletcher being the on-site “Grummanologist” to answer your technical inquiries. In addition to David, Garner Rice has over 24 years experience exclusively with Grumman aircraft and can answer almost any question.
 
Ron Levy said:
I know a lot of highly reputable paint shops which fill dents/dings with bondo during paint jobs when there is no cracking or the like. As that work has always been signed off by an A&P, I've always assumed it was legitimate.
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Legal ? Probably.

How much "Filler" would you like in your aircraft.

I don't believe the proper repair would be filler. Specially on stressed skin like the Grumman.

the issue will probably depend upon how much filler it will take. I've seen minor hail damage filled but wrinkles ?

I think If I were to repair that aircraft, I'd find a donor aircraft and remove the undamaged parts I needed.

Bondo or fillers don't do it for me.
 
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Outboard right hand wing skin, with wrinkles. On a Grumman. (or any other airplane for that matter). :yikes: Best give it the old "quarter test". I'll wager theres some de-lam there, or bent inner structure.
Sure Bondo will fix it to look nice. But....
 
bluerooster said:
Outboard right hand wing skin, with wrinkles. On a Grumman. (or any other airplane for that matter). :yikes: Best give it the old "quarter test". I'll wager theres some de-lam there, or bent inner structure.
Sure Bondo will fix it to look nice. But....
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I do not believe that skin is honeycomb.

proper repair would be to replace it.
 
Tom-D said:
I don't believe the proper repair would be filler. Specially on stressed skin like the Grumman.
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The Grumman wing is not a stressed skin design. If it were, the wing skins would not be .020"

Tom-D said:
the issue will probably depend upon how much filler it will take. I've seen minor hail damage filled but wrinkles ?
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I believe the damage being referred to here is shown in this picture, at the RH outer leading edge.

$(KGrHqMOKpIFGLw49p3RBRn2vmguDg~~60_3.JPG


That location is very easy to access from behind. I've seen worse hail damage than that fixed by massaging the damage out from behind and filling the remainder of the cosmetic damage with filler. If the damage is t0o great to be worked out, the repair listed in the AMM is pretty simple and common to other manufacture's methods. Cut out the damaged area, fabricate repair filler and backside doubler, flush rivet in place, APPLY EPOXY FILLER AS NECESSARY, and sand smooth.

Tom-D said:
I think If I were to repair that aircraft, I'd find a donor aircraft and remove the undamaged parts I needed.
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That's an option too. The outer 1/3 panel of the wing is easily removable and serviceable used spares are available if you know who to call. No need to part out another airplane just to get one.

Tom-D said:
Bondo or fillers don't do it for me.
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Even when they are specified in the AMM?
 
slacktide said:
The Grumman wing is not a stressed skin design. If it were, the wing skins would not be .020"
just because the wing has a spar doesn't mean the skins are not a part of the structure. Cessna uses .016 and calls it stressed skin.


I believe the damage being referred to here is shown in this picture, at the RH outer leading edge.
There is a specified repair for that type of damage see the MM

$(KGrHqMOKpIFGLw49p3RBRn2vmguDg~~60_3.JPG


That location is very easy to access from behind. I've seen worse hail damage than that fixed by massaging the damage out from behind and filling the remainder of the cosmetic damage with filler. If the damage is t0o great to be worked out, the repair listed in the AMM is pretty simple and common to other manufacture's methods. Cut out the damaged area, fabricate repair filler and backside doubler, flush rivet in place, APPLY EPOXY FILLER AS NECESSARY, and sand smooth.

That flush rivet repair described is in the MM but when done correctly it will need no filler

That's an option too. The outer 1/3 panel of the wing is easily removable and serviceable used spares are available if you know who to call. No need to part out another airplane just to get one.

some one did or there would not be used parts on the market.

Even when they are specified in the AMM?
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I repeat my self, "how much filler do you want in your aircraft"? when a flush rivet repair is completed correctly 2 coats of sand able primer will fill and deviations and hide the repair.
 
Tom-D said:
I repeat my self, "how much filler do you want in your aircraft"? when a flush rivet repair is completed correctly 2 coats of sand able primer will fill and deviations and hide the repair.
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You'd prefer zero filler, but the reality is that it is more practical in many circumstances to apply a little filler than to engage in structural repairs to fix cosmetic problems...
 
kyleb said:
You'd prefer zero filler, but the reality is that it is more practical in many circumstances to apply a little filler than to engage in structural repairs to fix cosmetic problems...
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That's true when you are excepting sub standard repairs.

I've done a good many annual inspections and I can spot filler 99% of the time.

as can most buyers.
 
The majority of what Tom posts about Grummans is based on his own personal opinions, and by his own admission, without much experience on the type. The maintenance and structural repair manuals tell use what can be repaired on these types, as well as how. Fletchair (which posted the ads) is probably the #1 expert on the planet (followed closely by Ken Blackman at AirMods NW, John Sjaardema at Excel Air, Bill Scott in Kentucky, and Bob Steward in Alabama) on how to fix Grummans. You want to know about repairing Grummans, talk to one of the Grumman maintenance experts.
 
Tom-D said:
I do not believe that skin is honeycomb.

proper repair would be to replace it.
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No, it's not honeycomb.
But it's an integral part of the structure of the wing.
It being wrinkled, leads me to believe that something has moved out of place. Else it wouldn't be wrinkled. :rolleyes:
IIRC these skins are glued on. (or are they only glued at the trailing edge) I know that some Grummans suffer from Delam (glue joint failure) of the (wing) skins. But only certian ones, I forget what the exact serial numbers are, that are affected, so every one that I look at gets the "quarter test". The honeycomb parts are in the fuselage.

Yes the only proper repair is replacing the skin, and whatever is under it that's bent causing the skin to be wrinkled. Not "Bondo".
 
slacktide said:
The Grumman wing is not a stressed skin design. If it were, the wing skins would not be .020"



I believe the damage being referred to here is shown in this picture, at the RH outer leading edge.

$(KGrHqMOKpIFGLw49p3RBRn2vmguDg~~60_3.JPG


That location is very easy to access from behind. I've seen worse hail damage than that fixed by massaging the damage out from behind and filling the remainder of the cosmetic damage with filler. If the damage is t0o great to be worked out, the repair listed in the AMM is pretty simple and common to other manufacture's methods. Cut out the damaged area, fabricate repair filler and backside doubler, flush rivet in place, APPLY EPOXY FILLER AS NECESSARY, and sand smooth.



That's an option too. The outer 1/3 panel of the wing is easily removable and serviceable used spares are available if you know who to call. No need to part out another airplane just to get one.



Even when they are specified in the AMM?
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That photo explains a lot.
When someone mentions "wrinkled wing skin" I'm picturing wrinkles running diagonally over the surface, indicating structural damage, and "out of square" type stuff. Not a ding in the leading edge.
In the photo above there appears to be separation between the outboard panel, and the adjacent panel. Not a good thing. 'course it could just be light and shadow.
I'm no Grumman expert (I've owned one though) But I would think that wing want further inspection prior to "fixin' th' dent".
 
bluerooster said:
That photo explains a lot.
When someone mentions "wrinkled wing skin" I'm picturing wrinkles running diagonally over the surface, indicating structural damage, and "out of square" type stuff. Not a ding in the leading edge.
In the photo above there appears to be separation between the outboard panel, and the adjacent panel. Not a good thing. 'course it could just be light and shadow.
I'm no Grumman expert (I've owned one though) But I would think that wing want further inspection prior to "fixin' th' dent".
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Yes. I think now that that is the "wrinkle", not the hangar rash on the leading edge.
 
kyleb said:
You'd prefer zero filler, but the reality is that it is more practical in many circumstances to apply a little filler than to engage in structural repairs to fix cosmetic problems...
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In my line of work when you fix the underlying structure, the cosmetics take care of themselves.





I've spent a lot of time straigtening out the work performed by "premier" shops who specialize in one make or the other. And due to their **** poor workmanship, the owner, (within a year) calls upon me to get it ironed out.
Case in point; a "premiere" Mooney shop in TX painted a guys airplane, (Mooney 201) in the process the removed a radome from the right wing.
Rather than replace that panel, they elected to invoke AC43.13, and using a doubler, patched the holein the leading edge of the wing. Then in an effort to hide the fact that there was ever anything there before, they packed it fulla bondo. Actually changed the shape of the airfoil in that area. 6 months later, it starts comming off in large chunks. Hmmm.
But they got paid. So I get to repair the damage. After removing the filler, I find that there was no need for that much. except they thought that if it was thicker it would hold up longer. :rolleyes:
#1 they filled a rivited flush seam, BIG no-no. (if you want it to last)
#2 they tried to add more filler to "make it hold up", BIG no-no. (if you really want it to last)
When I got done, It looks good, Proper shape for the airfoil, and has had no trouble for over 2 years now. Took me a weekend.
I've also hadda come back and spot repair several areas on the same airplane, where (due to **** poor prep work) the paint was flaking off in large chunks. All done by a specialty shop.
Another case; a Comanche 235, owner asked me to do a few things while it was down for annual. Sure, whatcha need. Usual things, leading edges, spinner, cowling, landing gear, Then vertical stabilizer, paint flying off the sides, and rudder. I mentioned that it still looked good for a 40 year old paintjob, that's when I was informed that it was done 2 years ago by a High dollar Piper specialty shop in FL. (oops). Got the job, and a referral.
 
Tom-D said:
That's true when you are excepting sub standard repairs.

I've done a good many annual inspections and I can spot filler 99% of the time.

as can most buyers.
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I think accepting is the word yer lookin' for. :stirpot: :D
 
bluerooster said:
.
In the photo above there appears to be separation between the outboard panel, and the adjacent panel. Not a good thing. 'course it could just be light and shadow.
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If by adjacent panel, you mean the one inboard, that's a cosmetic cap strip that covers up the butt-joint between the inboard and outboard panels. It is about 3/16 higher than the wing surface and is attached by a few pull rivets and not structural... the only structural connection between the inboard and outboard panels occurs at the spar (hence my comment that it is not a stressed skin design. There is NO structural connection between the inboard, center, and outboard skins.)

If you mean between the wingtip and the damaged panel, the wingtip is held on by ~48 screws... which are not currently installed. The wingtip is flying in loose formation at this point.
 
slacktide said:
No, that's how they all look.

IMG_9006.jpg
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I do not believe that one could buy the aircraft on E-bay, and make it look like this aircraft, and sell it at a profit.

it might be a fun project, but you would be working for free.
 
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