cowl rising

I just noticed today, on the right side as I was flying the top cowl on bottom right would expand out about 1/4 of an inch or so. just before the piano hinge. it is secured properly looks like a pressure expension. might have always been doing it. is there a cure for this

thanks

dan carley

Interesting. At about 200 MPH mine starts to cave in on the top between the baffle and piano hinge. Think right above the oil filter.

I have screws where the cowl attaches to the checks and they have pulled out. Maybe its lifting there and going down in the middle?

cowl

since my cowl is rising up do to pressure, I was thinking of maybe making a relief hole so the air can pass through. any ideas about that

dan carley

What I did

I have a screw/nutplate at the aft lower corner of the upper cowl, and the upper aft corner of the lower cowl that secures them to the cheek extension just above and below the end of the hinge pin. I made closeouts for the cheek extensions so air doesn't go into them. Its a fairly high pressure area. After 250 hrs., I see no signs of any cowl deformation or fasteners pulling anywhere. I have seen several -4s with the area at the aft end of the pin wearing and loose fitting, so the 4 extra screws keep it very tight.