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Cowling Update

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GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Sun Nov 05, 2006 1:04 am Post subject: Cowling Update

Well, there is good news and bad news.



First, the good news:  The DER has finally accepted my drawings and the 

stress analysis is done.  It looks like the drawings and Project Plan 

and Test Plan and PMA paperwork and hell I forget what else, will be 

submitted within a few weeks.  Finally.



The bad news:  I was going to just include all of the planes built 

under the AA5, AA5A, AA5B, and AG5B type certificate.  Then, one of the 

three DERs working on the project said, "I was reading the TCDS (Type 

Certificate Data Sheet) and it says the AA5 and AA5A have an O320.  Do 

you have to change anything to make your cowling work on these planes?" 

  Ah, well, (dancing as best I could) . . . . Probably.  "Then, you'll 

have to do those under a different STC, but, now it''l be easier 

because you already know what to do."



Bad news continued.  "Question." the DER says.  "You were telling us 

that the AG5B has a carbon fiber cowling.  Are there any other 

differences between the AA5B and the AG5B?"  Ah, well, the inlet air 

induction is different.  I went on to explain how American General 

screwed up the inlet and airbox design.  "So, then, it doesn't use the 

same airbox as used on an AA5B Tiger?"  I told them, "No. ... BUT.... I 

could use the AA5B airbox, but I'd have to get used ones or have them 

made."



So, unless the AG5B drivers that want my cowling can find an AA5B 

airbox, they will have to wait until I get a NEW design approved with a 

carb air inlet that can use the AG5B airboxes (2, yes, they have two.)



So, the bill to finish the project is a tad under $10,000.



Any more takers on a PRE-certification sales price of $6,000?



I would imagine the finished cowling will be around $8,000.  I'm going 

to try and hold the price down.



Gary

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Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)minetfiber.com
Guest

Posted: Sun Nov 05, 2006 6:52 am Post subject: Cowling Update

Will your initial STC include the AG5B then, provided it conforms to the 

AA5B inlet and airbox design? This might raise some other issues like the 

throttle cable length and location coming out of the firewall.



Does your engine induction air come off the back of cylinder #3 as it does 

on the AA5B?



Cliff  A&P/IA

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GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Tue Nov 07, 2006 12:23 am Post subject: Cowling Update

I'm glad you brought up the different throttle cable length and 

location.  Those things, though needing to be resolved, are doable.



Yes, I'm taking the air off the back of #3.



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_________________
Gary
AuCountry Aviation
Home of Team Grumman

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Fri Nov 10, 2006 10:23 am Post subject: cowling update

Mycowling wouldn't fit any engine put on an AA1.  I said it would 

physically fit the AA1.  It's way too long for the AA1.



What are you fighting on the PF installation?  I have a customer who 

just brought in an AA5 and wants the short stack PF put on it.  It 

seems to me that it's pretty straight forward.  I'll be installing it 

in a few days.



As soon as I get the cowling approved for the Tiger, I want to start on 

the Traveler.  Let's see, how long will it take???  My guess is, 

fitting the cowling, making the baffles, and getting the drawings done 

will take about a year .... IF I have a plane to work with.  Keep in 

mind, I also need to run a business and make enough money to pay bills 

as well as push several projects forward ... such as:  new wheel pants, 

new wing tips, fiberglass horizontal root fillets, fiberglass tips for 

Traveler, Cheetah, and Tiger horizontal tips, Fiberglass rudder tips, 

and a redesigned fiberglass tail cone.



Are you installing the short stack?



Gary



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Gary
AuCountry Aviation
Home of Team Grumman

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Fri Nov 10, 2006 11:00 am Post subject: Cowling Update

OK, so, no one wants in on the early cowlings.  Come on,  Get the word 

out.  Someone must want one of the early cowlings.  Just $2,000 down 

buys an $8,000 cowling at 25% off.



OK.  Well, as soon as I can afford it, I'm going to tackle a parallel 

valve IO360 with a constant speed prop.  Any takers on that????

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Gary
AuCountry Aviation
Home of Team Grumman

Phil(at)ReliantAir.com
Guest

Posted: Mon Nov 13, 2006 6:09 am Post subject: Cowling Update

Gary, Do you have an estimated availability yet on the cowling. Is it 2007

or later?.  If I opt in on the early purchase offer does that mean I have to

bring my tiger to you?  That's probably a deal killer for me because I'm

based in Danbury, CT.



Thanks,

Phil Kelsey

Reliant Air Charter



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GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Mon Nov 13, 2006 8:40 am Post subject: Cowling Update

In the ideal world . . . . .   yes, I'll be able to send out the kit 

and you can install it.  The first couple, I'd like to install just to 

make sure the installation instructions make sense.  The DER is 

insisting things like the landing light installation be pre-located and 

pre-drilled so that there is no need to include that in the 

installation instructions.  I would like to be able to locate and 

pre-drill the cam locks.  The buyer is going to be responsible for 

getting the center hinge, separating the upper cowling into two pieces, 

and trimming and fitting the parts prior to installing the hinge.  It 

takes me 4 to 10 hours to fit the hinge and another 4 to 10 hours to 

fit the upper to the lower before the cam locks can be drilled.  

Installing my cowling on my plane took me two weeks.  The flexible 

baffle seals, an extremely important part of the installation, will 

have to be done by the installer.  I hope to have a lot of pics so the 

installer can copy the installation.  I have templates for the baffles. 

 Hopefully, they'll fit all the installations.



Several years ago, I had a customer get the LoPresti nose bowl because 

Dave Fletcher told her the temps would be better.  A West Coast shop 

that does work for LoPresti, installed the nose bowl.  Her temps were 

actually a LOT worse.  She brought the plane to me.  I would guess 

there was an equal amount of air being forced into the lower part of 

the engine compartment as was on top.  That is, no pressure drop across 

the cylinders; i.e., no cooling air flow.  The inlets on the LoPresti 

nose bowl don't provide as close of a fit or as much as a fool proof 

installation as does the stock cowling.  It takes a lot of work to 

properly seal the top from the bottom with the LoPresti nose bowl.



My cowling fits really tight.  There is less than 1/2 inch between any 

sealing surface. The space between the cowling and the spinner is the 

thickness of a paint stir stick.  Part of the "trim to fit" for the 

cowling is because not all engines are installed with the same number 

of shims.  The installation instructions will include a recommended 

number of shims.

--

_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)minetfiber.com
Guest

Posted: Tue Nov 14, 2006 5:51 am Post subject: Cowling Update

The buyer is going to be responsible for

 	  Quote: 	
		   getting the center hinge, separating the upper cowling into two pieces, 

 and trimming and fitting the parts prior to installing the hinge.  It 

 takes me 4 to 10 hours to fit the hinge and another 4 to 10 hours to fit 

 the upper to the lower before the cam locks can be drilled.


	


Gary, I thought your cowling had a top cowl that was not-hinged and attached 

to the lower cowl with Cam-Lok fasteners.  Have you redesigned it from what 

you had initially on your plane?



Cliff

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Tue Nov 14, 2006 10:00 am Post subject: Cowling Update

My cowling uses the same hinges as does the stock Grummans.  I use cam 

locks to hold it down.  Did you get a chance to look at it in 

Fredericksburg?



At one point I was going to just have a removable top cowl but the 

structure to make the center strong enough for a Vne + 10% dive was too 

invasive into the area where baffles go along the back of the engine.



--

_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)minetfiber.com
Guest

Posted: Tue Nov 14, 2006 6:13 pm Post subject: Cowling Update

No, I think the last time I looked at it you did not have a hinged top cowl 

as I recall.

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