Careless mechanics...

Ken Ibold

Ken Ibold

Final Approach
Joined
Feb 21, 2005
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Jacksonville, Florida
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Display name:
Ken Ibold
My airplane just came out of annual. I had always been a little disappointed in the speed, as it seemed to get stock speed despite having every speed mod known to LoPresti.

The LoPresti cowl for the PA-32 includes a 3-piece nose gear door -- one on each side and door that comes across the front.

My mechanic -- his first time doing an annual on this airplane -- discovered the front door was never hooked up to retract!! So at cruise, there was an 8 x18 inch flat plate perpendicular to the wind. Now, this airplane has been through three annuals (one a pre-buy we commissioned last February) since the cowl was installed, and no one bothered to note this during the gear swing?!?!?

(On the right in the photo is a cowl flap. The offending gear door is front and center.)
 

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Would it fold back freely in flight or was it locked fully open?
 
KennyFlys said:
Would it fold back freely in flight or was it locked fully open?
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Ken Ibold said:
It appeared that it could fold back maybe 15 degrees, but the spring pushing it forward is pretty powerful, so I don't think it would streamline that much.
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Even so during annual when they check the gear they should have noticed that the gear door did not retract. I am sure there was little to no breeze in the hangar.
 
smigaldi said:
Even so during annual when they check the gear they should have noticed that the gear door did not retract. I am sure there was little to no breeze in the hangar.
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That's a point I hadn't thought of. So, at least once during one of those annuals... wouldn't they have lifted the airframe and cycled the gear for proper operation? That certainly seems like a reasonable thing to do along with an inspection for fatigue.

Had they done so, I'm sure that one door section would clearly show to be still extended.
 
KennyFlys said:
That's a point I hadn't thought of. So, at least once during one of those annuals... wouldn't they have lifted the airframe and cycled the gear for proper operation? That certainly seems like a reasonable thing to do along with an inspection for fatigue.

Had they done so, I'm sure that one door section would clearly show to be still extended.
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My point exactly.
 
Is it the same shop doing the annuals every year? If not, it would be very interesting to make a little 'visit' to the previous shops and try to lead them down the bunny hole to see how deep they get themselves (Oh yes, we definitely checked that) before you inform them of your recent discovery. Oh yeah... And take a video camera so you can share their response. :)
 
CJones said:
Is it the same shop doing the annuals every year? If not, it would be very interesting to make a little 'visit' to the previous shops and try to lead them down the bunny hole to see how deep they get themselves (Oh yes, we definitely checked that) before you inform them of your recent discovery. Oh yeah... And take a video camera so you can share their response. :)
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The cowl was installed by a highly reputable shop in Smoketown, PA, during the annual two years ago. Then we had our prebuy/annual done in Hagerstown last year. This is the first annual this mechanic has done.

So the initial installer blew it and the prebuy shop blew it. I can cut them a little slack because the LoPresti cowl is an uncommon item and the main doors did close, but it seems self evident that a drag-reducing cowl should not have a flat plate sticking down when the gear's up.
 
I don't know if this the case here, but many aircraft gear swings are done with the cowl off.

No excuse not to hook every thing up when you replace the cowl.

The landing light wires get me pretty often.
 
NC19143 said:
I don't know if this the case here, but many aircraft gear swings are done with the cowl off.

No excuse not to hook every thing up when you replace the cowl.

The landing light wires get me pretty often.
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On the LoPresti cowl, the gear doors are not attached to the cowl. The cowl is split vertically and all 3 nose gear doors stay in place when the cowl comes off.

I went back to the air-to-airs the seller sent me when we were looking at this particular airplane, and if you blow it them up you can see the center door is not retracted.

I may just get 5 free knots here!
 
Wow Ken I guess you didn't plan on buying a LoPresti Speed break. Thats almost like what it is.
 
Ken Ibold said:
I may just get 5 free knots here!
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Seems to me you already paid for those knots and then some.

WRT this being missed on an annual inspection, I'm not at all surprised. When I've watched or participated in "gear swinging" it appeared that most of the attention was focused on downlock tension and unusual noises.
 
Go checkout Kareem Fahmi's experience with his reman engine on the red board. This is nothing....
 
Ken Ibold said:
On the LoPresti cowl, the gear doors are not attached to the cowl. The cowl is split vertically and all 3 nose gear doors stay in place when the cowl comes off.

I went back to the air-to-airs the seller sent me when we were looking at this particular airplane, and if you blow it them up you can see the center door is not retracted.

I may just get 5 free knots here!
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The irony here: The previous owners sunk $$$$'s into speed mods, gets them improperly installed, and probably ended up being slower than stock. :redface:
 
mikea said:
The irony here: The previous owners sunk $$$$'s into speed mods, gets them improperly installed, and probably ended up being slower than stock. :redface:
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I had been getting about book numbers, which puzzled me. The exception to this is that I was getting higher than stock manifold pressure at altitude because of the prop-pulse synchronization with the intake valves.

I checked the tach with an optical prop gauge, checked the manifold pressure gauge, all of the power-setting cables and linkages, thinking perhaps it was cruising at a lower power setting than intended, even though there was no commensurate decrease in fuel burn. Now, speed mod makers put a lot of claims into their marketing materials, but in the official POH supplements they back off the speed claims and simply say it will not perform WORSE than stock. I thought the LoPresti guys were above the nonsense, and for almost 20K you'd expect the LoPresti cowl would do SOMETHING. I figured maybe the previous owner had started with a slower-than-book crooked airframe or something. I had talked with my mechanic about it and we were going to launch a rigging investigation until he discovered this little foible.
 
Have you talked with LoPresti? I wonder if this has happen with other birds and gone undetected for any period of time.
 
Funny, I was just thinking to myself tonight, about another issue, that if I don't see book numbers, I start scratching my head. +/-1-2 kts, ok, but more than that something's up. Ice, drag (them durn cowl flaps), mixture, something...

I would never suspect something as obvious as this!!!
 
It'll be interesting to see how this affects where the trim is set in cruise configuration.
 
Geesh Ken. Now that it's been discovered, is the shop willing to do anything to make things right? One of my biggest frustrations is finding an error and the shop thinks they should just fix it at the shop rate.

Best,

Dave
 
Sometimes the solutions are simple. We had a Jet prop that was much slower than the others, most owners believe that theirs is the fastest. The modifier dragged it back and re-rigged, even sent the engine back to Pratt with no solution. The ship shows up in our shop for an annual insp. Part of our annual is to pressurize the cabin to max differential and to inflate the de-ice boots in the shop. When the cabin got to 5psi dif. the lower wing de-ice boots were fully inflated. You can't see them in flight. Once the open hose was reconnected the airspeed returned to normal.

Regards, Kevin
 
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