Boot Cowl Extension Orientation

[robcaldwell]

Do I have this Boot Cowl Extension oriented properly? Nothing in the plans or the manuals I have cover this. If I do have this correct, what is used to attached the rear flared portions (see red arrows in the picture).

On this same subject, do we have more comprehensive diagrams for the cowlings? What I do have in the Newton's and AviPro manuals are not helping me as well as I would like. Thanks!

 

[Mark Goldberg]

Rob, I am not really following your question about the boot cowl "extension".

In an early BearTracks (in Bob's Book that came with your plans) - you will see Bob's drawing of what he wants in the cowling. Not too complicated once you see the drawing. Mark

 

[robcaldwell]

Bob doesn't address this portion of the cowl section in his book. At the bottom between station B & C. In the pictures, I am demonstrating one shot with the precut cowl piece labeled "Boot Cowl Extension" placed over B & C. Aft of C, there are two flared out pieces that do not have an attachment point. If this is the correct orientation, then the oleos are blocked. Should I modify this cowl to accommodate the oleos? I'm guessing I have it all wrong, but cannot determine the proper orientation of this piece...

 

[Mark Goldberg]

Very likely you need to cut holes for the shock struts. Mark

 

[PaulSA]

I fitted the Bulkhead at Station B with the flange aft, but It should work with it forward as the pieces supplied are all slightly over-size so the is some flex. The aft sections of the lower and side boot cowl extensions are fitted to angle pieces which you have to design and fit - the build manual covers this. I used clamps plus rivets to the lower door frame for the side and one of the tabs on the bottom. Sorry, but I am away for a month so can't post photos. It took me a while to work out how to do it. Also, the side extensions wrap around the lower longeron tube and fix to the bottom to give more stability.

And, yes, you have to trim around the gear struts. The required shape of the hole is in with the plans pack somewhere. I cut over-size and plan to sort out the cosmetics with the boot cowl to strut fairings.

 

[robcaldwell]

I fitted the Bulkhead at Station B with the flange aft, but It should work with it forward as the pieces supplied are all slightly over-size so the is some flex. The aft sections of the lower and side boot cowl extensions are fitted to angle pieces which you have to design and fit - the build manual covers this. I used clamps plus rivets to the lower door frame for the side and one of the tabs on the bottom. Sorry, but I am away for a month so can't post photos. It took me a while to work out how to do it. Also, the side extensions wrap around the lower longeron tube and fix to the bottom to give more stability.

And, yes, you have to trim around the gear struts. The required shape of the hole is in with the plans pack somewhere. I cut over-size and plan to sort out the cosmetics with the boot cowl to strut fairings.

Thanks so much, Paul. This is very helpful. Would love to see pictures when you have time. With my kit, the bulkhead at station B came with a description specifically stating that the flange should be facing forward. It was apparent they wanted this known.

This seems to be an area not covered in the plans or manuals, that I can locate. I will dive deeper into the build manual.

 

[PaulSA]

The build manual states that the bulkhead should be fitted on the aft side of station B with the flange forward, but that is for the “A” model. As you see, the tabs have been moved to the front. The SS tunnel fitted perfectly when I orientated the flange aft.......

I also found I had to trim about 1” off the bulkhead to get the profile of the lower boot cowl correct.

 

[PaulSA]

Sorry for the delay in posting these photos - hope they help. Not saying the only or best way to do it - it's just A way.....

 

[Archer39J]

Quite helpful to me, thanks for the pics!

 

[svyolo]

I am doing the lower boot cowl/tunnel etc. No problem figuring it out thanks to all the info. I do have a question about the lower fabric termination. The lower part of station C that captures the end of lower stringers is only 3/8" tubing. Not a lot to terminate the fabric to. I am thinking I should attach some angle to the tabs with nut plates to both mount the lower aft boot cowl, and terminate the fabric. Is this the intention/consensus?

 

[Mark Goldberg]

You can glue/wrap the fabric around the 3/8" tube. It has held up on mine for a long time. Mark

 

[Battson]

No need for additional attachments. Just make sure the paint is roughed up a little, cleaned before you glue, use plenty of glue and wrap the fabric all the way around.