pdf Gfa ad 501 Cancelled 2017.03.29 Popular

INCREASE OF SERVICE LIFE FROM 6000 TO 12000 HRS / INSPECTION OF ELEVATOR CONTROL LINKAGE / ADDITIONAL SAFETY DEVICE FOR THE LANDING GEAR REAR BOLTS / EXCHANGE OF PAGES IN THE FLIGHT AND MAINTENANCE MANUAL

CANCELLED - Refer Type Certificate Holders current data

Applicable to the ASH 25 sailplanes and ASH 25 E powered sailplanes.

1.) Increase of service life from 6000 to 12000 hours: Fatigue tests on fibre composite wings and wing spars have demonstrated that a service life expectancy of 12000 hours can be reached for these structural components. As these fatigue test programs did not examine the entire aircraft made of fibre composite, the service life of 12000 hours can be granted only if the long-term airworthiness of each individual aircraft is demonstrated in a special multi-stage inspection program (over and above the mandatory annual C of A inspections) for the purpose of increasing the service life.

2.) Inspection of the elevator control linkage: In the case of two ASH 25, damages to the elevator control linkage have been overlooked after inadequately accomplished repairs in the areas of the landing gear and of the fin. These damages due to overstressing the elevator control linkage can lead to reduced control stiffness. The decrease of elevator frequency caused by this can in turn when being initiated accordingly, lead to a frequency coupling with the horizontal stabiliser and thus lead to flutter.

3.) Additional safety device for the landing gear rear bolts: The two bolted connections of the landing gear H-strut to the fittings at the rear landing gear bulkhead have come loose in single cases. If these bolted connections are not covered with screw safety varnish, the bolted connection on each side must be undone and a lockplate must be added which must be bent upwards after retightening of the bolted connection.

Manufacturer’s ASH 25 Technical Note No. 14 and ASH 25 E Technical Note No. 12 (attached to this AD). Further material, drawings and manual pages can be obtained from the Australian Schleicher agent or Alexander Schleicher GmbH & Co, Segelflugzeugbau PO Box 60 36161 Poppenhausen Germany  Ph. +49 6658 890; Fax +49 6658 8940.