Brief Description: Worked on doorpost top channels.
Removed doubler from RH channell at top of RH doorpost that was damaged when we removed the rivets from it. See previous post. Behind the doubler found notched spot at lower bend in flange of channel. The LH channel has similar notch but no doubler. Why? Close examination of the channel revealed a crack in the inside flange. I stop drilled the crack in preparation for covering with a doubler. The LH channel has the matching notch in the outer flange with no doubler, and the inside flange has a crack that was stop drilled and covered with a doubler.
The doublers were made of .050 material, same as channels. Some did not have an appropriate number of rivets per 43.13.
I started making four new doublers from .063 stock, and will finish and install those next on all four flanges.
