N247BR

Engine Cowling - Cowling Mount



Cowling Mount
Cowling Mount
Early on I decided to use a piano hinge to join the top and bnottom of the cowling for both an ease of installation and remove as well as the cleaner look of not having screw or other fasteners running the length of the cowling.  I am very happy with that decision even though like every other deviation from the plans it cost a lot of hours.
Cowling Mount
Cowling Mount
Cowling Mount
Cowling Mount
I used the adjustable cowling fasteners from Aircraft Spruce.  The recepticle is installed in the fuselage and will be adjusted after the cowling and fuselage have been painted and finished.  The resulting fastner is nearly flush with the surface after installation.
Cowling Mount
Cowling Mount
Cowling Mount
Cowling Mount
The fasteners were only installed across the top and on the sides of the lower cowling.  The hinge pin will also act as a fastner on the point where the upper and lower cowling meet.  What I like the most about these fasteners is that they are quick connect requiring only a 1/4 turn to lock in place.

Cowling Mount

Mounting or removing the cowling will require the prop to be removed since the three bladed prop doesn't leave enough room to clear the front of the cowling.

This photo shows the connection to be made between the air box and the cowling air inlet.  The cowling will slide backwards with the inner tube of the air inlet sliding into the air box inlet.  It takes a bit of finesse to slide it in but it form a good seal and stops the cowling at the proper place.  It provides support for the cowling once installed.

The important part for me was that I can install the cowling by myself.

Cowling Mount Cowling Mount
I have mounted and dismounted this cowling many times during the construction process with no problems.  I was always able to slide the piano hinge pin into place without substantial problems.  That was BEFORE painting.  I failed to account for the thickness of the paint causing the gap between the top and bottom of the cowling to expand to the point that I could not get the thing together.

The quarter turn adjustable fasteners turned out to be both easier and more difficult to adjust than anticipated.  More difficult because somehow some tiny washers or something got down inside the receptacles and blocked the screw pin from setting correctly.  Took me forever to figure out what was wrong.  Once that issue was solved, the actual adjustments went very smoothly.


Fixing the problem with inserting the hinge pin required sanding the overlap between the fuselage and cowling to remove some of the paint build up.  The inside of the cowling on the top at the corners up to the first fasteners had to be ground down to remove some of the thickness.  The lower cowling required some inside grinding to remove the thickness as well.  Finally, the installation process required the lower cowling to be left loose except for the third fastener from the top on each side until the pin is installed.  Once the pin is installed the remaining fasteners can be tied down.

Finally, the hinge pin was cut to length and the insert point filed to a sharp point to ease the insertion.  The tab is partially embedded into the cowling and turned down for locking into place.  Haven't decided how I am going to cover the tab yet and it really isn't at the top of my issues list.