Cowl attachment

[Friarpuk]

G'day folks

 

Have been pondering how to secure the top half of the cowl so I can easily remove it for engine inspection and maintainence. I'm not a big fan of the little cowl screws that chew out the fibreglass after time. However I have been wondering if the butterfly latches used on roady cases would do the trick. Has anyone out there got any ideas? These butterfly latches are in their own metal recesses making them easy to cut into the cowl.

 

Different types can be seen at http://www.penn-elcom.com/Default.asp?MC=1101000&GC=Group[url=http://www.penn-elcom.com/Default.asp?MC=1101000&GC=Group][/url]

 

What do others think?

 

 

[Guest ozzie]

Just take a walk around your local airport and look at the differnt types. dzus fastners seem to be the most popular. cowls seem to be an area of constant attention especially glass/metal cracking around the hole, beef it up. hard to get a cowl to sit tight and not rub itself to death or have to much tension and crack it.

 

Dzus fasteners are available in three types wing flush and oval

 

 

[Guest Maj Millard]

Don't care what you use, but just make sure they do the job, and you remember to latch them.

 

Went for a fly with a friend once in his new Tecnam P92 . He had done the preflight, and warm up, but he had forgotton to latch one side of the top cowl. (very similiar latches to Pipers X 2).

 

At around 250 ft right after takeoff, the top cowl, still attached on one side, flew up in front of us.

 

It continued to pop up and down in front of us, until we got the aircraft back on the ground, which by the way, was as quick as we safely could .

 

Basically it's scary as Shxx, and not very character building, and I wouldn't wish it on my worst enemy. It's very hard to ignore a cowl flapping up and down in front of the windshield, as you are wondering what it'll do next !!............and I don't expect I'll need to try it again any time soon............

 

 

[youngmic]

The piano hinge method is popular with many homebuilders.

 

Nearly as quick as Dzus fastners if rigged properly and makes for a flush neat appearance.

 

 

[Guest Maj Millard]

Yes piano hinges are very clean as per the RVs.........................

 

 

[facthunter]

Cowl fastening.

 

The piano hinges distribute the load well. Along the sides anyhow. nev.

 

 

[Guest keeffe]

Velcro, and blue tack.

 

;)

 

 

[Geoff]

J160 use the piano hinges never had a problem in 800hr

 

 

[Guest pelorus32]

J160 use the piano hinges never had a problem in 800hr

G'day Geoff,

 

I'd be interested to understand how it is that piano hinges are fasteners? I can't get my head around it. Do you mean that its a set of hinges with a wire down the guts of it as the fastener?

 

I've used three different types of fasteners: the "over centre lock" on the Tecnams - a la the P92. These are quick and simple but it is possible - and done regularly too - to miss the top retaining part of the catch with the lever. Everything looks OK but nothing is latched.

 

The Dzus fasteners - OK but a bit fiddly. And finally the long hinges with a wire up the guts: in my experience these are either perfect and simple or you wish you'd never ever seen the #$$%@ things. If they line up and the wire goes in easily that's fine, but if the wire doesn't want to go in that's a pain.

 

My pick, despite the issues is the Tecnam type for opening for regular pre-flights etc and the long hinge with the wire for removing the cowls entirely. Once you have made the mistake with the Tecnam ones it tends to become automatic to check that the lever actually is under the catch.

 

Regards

 

Mike

 

 

[facthunter]

piano hinge.

 

Mike, It doesn't work as a hinge.(but it can IF it is straight) They can be bent to conform with the curve of , say the side of the cowl, and the wire is withdrawn to provide separation of the join. A mild point at the end of the wire facilitates "threading" the wire in. There is no chance of it coming out by itself, but if that is a concern, a small right angle bend at the end can be clipped down. They are not subject to rapid deterioration by vibration.. Nev...