February/ March P-47 Update 2017

Texas Flying Legends
By Chuck Cravens

This is a dimensionally stable, machined, cast aluminum toolingplate commonly called MIC-6 (MIC-6 ® is a registered trademark of Alcoa).

This is a dimensionally stable, machined, cast aluminum toolingplate commonly called MIC-6 (MIC-6 ® is a registered trademark of Alcoa).

Update

This month didn’t happen to have a great many visible changes to the P-47, so we will be brief this time.

Last month we saw the wing attach fittings ready to be magnetic particle tested and cad plated.  Those finished parts are back.  The other main project right now is building a fixture to begin assembling the forward fuselage.

Wing Fittings

These wing attach fittings connect the cross tie that runs through the fuselage to the wing itself. They are machined from billet steel because the original forgings would be cost prohibitive in a small batch. It would take the better part of a million dollars to have forged blanks made for the eight unique parts plus a few spares necessary for one airplane. Billet machining cut that cost by a factor of 30.

The engineering drawing for the lower cross tie is depicted here. This Republic Aviation Corporation engineering drawing is where the fabrication shop starts the process of creating the finished part. You may need to enlarge it on your screen to read the various notations. If you look carefully , there is a smaller drawing of the part located below and to the left of the main drawing.  This is an alternate form of the part, number 89F11989.  The difference is that the fluted grooves on the edges of the tapered section are omitted.  Since our P-47 had these alternate wing attach fittings, they are what we made.

Fuselage Fixture

The fixture was rendered in CAD before starting.  This is how it will appear when finished.

The fixture was rendered in CAD before starting.  This is how it will appear when finished.

This rendering shows the lower fuselage mounted in the fixture.

This rendering shows the lower fuselage mounted in the fixture.

Another view shows us the forward end of the lower fuselage in the fixture. 

Another view shows us the forward end of the lower fuselage in the fixture.

Eventually the upper fuselage will be built in the fixture and attached as it is assembled.

Eventually the upper fuselage will be built in the fixture and attached as it is assembled.

About the author

Leave a Reply