When someone mentions the perils of “aging aircraft,” most people probably think about airplanes, usually large ones like the Aloha Airlines Boeing 737 that suffered a ripped-open fuselage in April 1988, or of wings folding on firefighting air tankers, as happened to a C-130A in Walker, Calif., and a P4Y-2 near Estes Park, Colo., both in 2002. Helicopters age as well, and there is a surprising amount of research being conducted on the issue.
Much of the aging aircraft research results finds a public platform at the Joint Council on Aging Aircraft. This year, the ninth Joint FAA/DOD/NASA aging aircraft conference is being held from March 6 to 9 in Atlanta. The registration fee is $450.
Last year’s conference, held in Palm Springs, Calif., had six sessions targeting the helicopter community, ranging from a panel session on blade erosion to Modeling the Effects of Anomalies on the Lives of Rotorcraft Components; Crack-Growth Predictions in a Complex Helicopter Component Under Spectrum Loading; Transforming the U.S. Army Helicopter, CH-47D Chinook via Reliability Centered Maintenance; Effect of Rivet Conductivity on Crack Detection in Rotorcraft Joints; and Evaluation of Two Corrosion Retardant Rinse Water Additives for Possible Use on U.S. Army Helicopters.
This last session concluded that the corrosion rinse-water additives Chlor-Rid and ZI-200 are “not recommended for military aircraft due to pitting corrosion on aluminum and magnesium alloys.” Two other additives were tested, Cr-16 and Salt-away, and the presenter concluded that both substances “can potentially increase the SCC [stress-corrosion cracking] and HE [hydrogen embrittlement] susceptibility of some aerospace alloys used on helicopters. Therefore, neither CR-16 nor Salt-away is recommended for use on U.S. Army helicopters as an acceptable CRA [corrosion retardant rinse additive].”
This year’s aging aircraft conference features eight helicopter-specific sessions, including one that has to do with V-22 Osprey obsolescence verification, which seems odd given that the V-22 entered service only fairly recently. Clearly the V-22 community is planning ahead for the day when V-22s become aging tiltrotors.
For more information on the 2006 Aging Aircraft Conference, see www.agingaircraftconference.org/2006_2/index.php.