In the past three months Luke AFB has been having a lot of problems with the Drag Brace Fixture. One one time there weren't any calibrated fixures on the base. Some squadrons had to borrow a fixture from Nellis AFB to meet flying suspense dates.
The calibration procedure instructs PMEL to flip the unit upside-down during calibration. Significant sag could be seen on the side of the fixture that hung off the end due to gravity pulling it down.
The fixture was changed years ago. Originally it had an I-beam design and was very rigid, but now it's very flixible and doesn't pass cal very often. We've been in contact with many AFMETCAL engineers, Lockheed engineers, and Air Force support engineers at Hill to correct the problem of calibration and design of the fixture. Stuff gets done when there's no aircraft in the air! :-P
Engineers are about to change the maintenance manual calibration procedure so AFMETCAL will change the procedure too, but people at Luke (inclcuding myself) don't believe the changes will recognize all error.
The best way to avoid many problems to have the fixture go back to original "I-beam" design.
Some engineers don't believe there is a problem, because they haven't seen a big history of problems. Yet there's a warehous full of condemned fixtures.
Can you guys tell me what your experiences have been with this fixture? We will probably get a PWIG together to tackle this problem, but I thought I'd use this forum as well.
Thanks for any suggestions that you might have.
We're working on the Cal T.O., just got the draft from the engineer...should see it in a couple of months....red tape you know...
We've been using the new T.O. for about a month. It worked pretty well for us. We were going to use it with the other fixtures and let AFMETCAL know how it turned out, but now we're wayyy backed up and working Saturdays. :-( So we can't get to it right away.