Today (June 16) there was fatal accident involving a Millennium being flown at Hobbs New Mexico. After performing an intentional spin and recovery, the glider experienced a structural failure during a high speed pull up from a near vertical dive. At this time we are just piecing together the details of the accident and we know that the primary point of failure was the nose catch assembly of the glider. We ask that all Millennium owners not fly their gliders until we have determined under what conditions and why this assembly failed. If anyone has questions concerning this please call Bright Star Gliders at (707) 576-7627, 9:00AM-5:00PM PST, or e-mail me at mlbco@sirius.com.
Steve Morris
Bright Star Gliders, Inc.
(650) 424-9552 (Steve's number)
(707) 576-7627 (The shop)
Dear Millennium owner:
As many of you know, Michael "Hollywood" Champlin was killed when a Millennium he was flying experienced a structural failure of the nose catch mechanism during a high speed recovery from a spin. At this time we have spoken with an eye witness to the incident and have gathered information on the mechanism that failed.
The nose catch pin which protrudes from the bottom of the wing was bent to the side by the force of the metal tangs and the circle clip restraining the tangs then sheared off. This occurred some time during the high speed portion of the spin recovery, where the speed of the glider was estimated to be 100 mph. We designed the nose catch to withstand full rudder deployment loads at a Vne speed of 65 mph. At this flight condition the fully deployed rudders pull rearward on the tips of the D-tube with a force of 44 lbs each. For a safety factor of 1.5 the nose catch assembly must withstand 66 lbs of aft load at the wing tips before failure. Millenniums have been flight tested with full rudder deployment at Vne speed. We load tested a production Millennium just after the accident was reported and found that the joint failed at 70 lbs of load at the tip. This meets the estimated load plus safety factor at the Vne condition. The test was performed with a maximum misalignment of the tangs, meaning that the tangs were not resting against the bottom of the D-tubes, but were shimmed for a maximum 1/8" gap. This condition is a worst case loading because it places the greatest bending stress on the pin. The failure mode of the joint was identical to the Millennium that crashed, the pin bent and the circle clip sheared off.
Even though the stock configuration meets our load requirements, Hollywood's accident has shown us that this portion of the wing could fail in a dramatic manner at high speed and we have now strengthened this mechanism so that it will not be an initial point of failure. We have developed a system that uses a third steel tang and a threaded bolt instead of a clevis pin for locking the wings together. This system has the advantage that the tangs are always locked against the bottom of the D-tube when the tangs are secured with a wing nut (instead of a circle clip). We load tested this joint to failure and found that it can support 120 lbs of load at the wing tip before the D-tube skin (not the nose catch joint) failed. This is a 70% improvement in strength over the original system. We have also flight tested this modification up to Vne speed with both rudders deployed and have seen no signs of deformation or over stress in the nose catch assembly. The modification can be retrofit to all Millenniums using hand tools and we will be sending you a retrofit kit with installation instructions as soon as we can have the parts made (no more than 2 weeks, depending on the schedule of the laser cutting shop). There will be no charge for this. Pictures of the modified attachment can be seen at the following web site address:
We ask that all Millennium owners install these new parts for improved safety. We also want to remind everyone that you should never exceed the 65 mph Vne speed of your Millennium and please do not attempt any aerobatic maneuvers. The Millennium is not designed for performing aerobatics, it is designed for cross country soaring flight. An important factor in maintaining proper pitch control of your Millennium is to be sure to always wear your shoulder straps during flight because they help to prevent unwanted pitch inputs when experiencing negative g's in turbulence. The coupling between the pilots arm motion and the stick is very sensitive on the Millennium and if you are floating in the hang cage it is impossible to precisely regulate the pitch control. The shoulder straps help to limit this problem and should always be worn. Some pilots who frequently tow have mentioned forgetting to put these straps on and have experienced some exciting moments when encountering turbulence during tow.
We are profoundly saddened by the death of Michael Champlin and we want all of you to have the safest flying machine possible. If you have any questions please call our shop (707) 576-7627 or e-mail me at mlbco@sirius.com.
