Pivotal Success for B-1 Lancer team installing wing pins Published May 21, 2009 By Howdy Stout Tinker Public Affairs TINKER AIR FORCE BASE, Okla. -- A B-1B Lancer arrived at Tinker this week for unique inspections of the pivot pins that allow movement for the aircraft's swing wings. This is the second aircraft to undergo the prototype inspection to the pivot pins. Engineers from the AFMC 553rd ACSS/GFLB Aircraft Management Squadron developed the inspection technique, the first of its kind since the B-1 entered service more than 20 years ago. Aircraft Mechanics from the 565th Aircraft Maintenance Squadron accomplish the task. "It is a prototype process," explained Melvin Godwin, supervisor at the 565th. As the aging fleet faces higher demands for use, there were concerns over how the pivot pins were holding up. As a result, two high-time B-1s scheduled for normal depot maintenance would also have their pivot pins removed - along with surrounding bearings - and inspected for wear and possible replacement. The 565th took up the challenge, having already accomplished the removal and replacement of a B-1's wing, which involved removing the pivot pin. Engineers from the 553rd ACSS/GFLB and Mechanics from 565th travelled to Guam to remove and repair a burned-out wing on a B-1. The entire wing removal was accomplished in the field and in the open without benefit of depot-level facilities. "That was the first time we've ever removed a wing from an aircraft," Mr. Godwin said. "And it arrived here after a 23 hour flight with minimal defects." Inspecting the pivot pins involves removing the three-and-a-half-foot long, approximately 250-pound pin and surrounding shear bearings. Both pins and bearings are inspected for wear and are measured against original manufacturing specifications. If worn beyond safe limits, the pin, which can withstand 100,000 pounds of torque, will be replaced. So far, however, the first aircraft inspected showed no need for replacement. "The wear was nominal," Mr. Godwin explained. "All the dimensions were within allowable limits." Mr. Godwin says Tinker may incorporate the pin inspections on high-time aircraft as part of the normal depot-level maintenance. It is expected to extend the time the B-1 spends in maintenance at Tinker, but only selected, high-flight time aircraft will initially be inspected. "We'll get two this year and two next year," Mr. Godwin said. If significant wear is found on the pins of other aircraft, it may become a mandatory inspection for aircraft undergoing depot-level maintenance. With 66 aircraft in the fleet, each B-1 arrives at Tinker once every five years. "It just depends on what they find," Mr. Godwin said. "We haven't had to change one out yet."