Aluminium Cowls

clare wrote:
On Sat, 24 Jun 2006 22:51:05 +1000, "......... :-\)\)"
wrote:

Hi,

Can anyone tell me what alloy is used for the manufacture of aluminium nose
bowls on aircraft such as the Luscombe or C-140 or J-3 Cub ?

Also how are they made (hand beaten, drop hammer etc ??)

I assume they are formed in the 'O' condition ? If so are the heat treated
subsequent to forming or is the strain hardening as a result of the forming
process enough to harden and strengthen the metal ?


Most would have been made out of 24ST, which in today's alloy
desigination would be 2024. Forming would have been done by any of, or
combination of: hand form, stretcher press, drop hammer, or bladder
press. There would be some anealing and heat treatment depending on the
exact alloy used and the forming technique(s).

Craig C.

In article . com,
wrote:

clare wrote:
On Sat, 24 Jun 2006 22:51:05 +1000, "......... :-\)\)"
wrote:

Hi,

Can anyone tell me what alloy is used for the manufacture of aluminium nose
bowls on aircraft such as the Luscombe or C-140 or J-3 Cub ?

Also how are they made (hand beaten, drop hammer etc ??)

I assume they are formed in the 'O' condition ? If so are the heat treated
subsequent to forming or is the strain hardening as a result of the forming
process enough to harden and strengthen the metal ?


Most would have been made out of 24ST, which in today's alloy
desigination would be 2024. Forming would have been done by any of, or
combination of: hand form, stretcher press, drop hammer, or bladder
press. There would be some anealing and heat treatment depending on the
exact alloy used and the forming technique(s).

Craig C.

Usually, they are made from a weldable alloy, NOT 2024 (24ST)!. 5052,
6061, 3004 in soft (non-heat treated) form are often used. Many cowls
are formed as sections and then welded together to form the final piece.

Orval Fairbairn wrote:



Usually, they are made from a weldable alloy, NOT 2024 (24ST)!. 5052,
6061, 3004 in soft (non-heat treated) form are often used. Many cowls
are formed as sections and then welded together to form the final piece.

For many of those that are multipiece assemblies, you are correct. The
cowls for most of the birds that I have worked on were one piece
sections, with just mechanical fastner assembly. My L-5 has both types
of assemblies on it and my Fairchild cowlings were riveted stampings.

Craig C.