Feds research helo aging effects
When someone mentions the perils of “aging aircraft,” most people probably think about airplanes, usually large ones like the Aloha Airlines Boeing 737 tha

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.