Mandatory Piper Seneca inspections proposed

The FAA estimates that the proposed AD will affect 25 Piper PA–34-220T airplanes in the U.S. registry, with an estimated cost of $355 per aircraft for the required inspections of the rudder control cable, and to reroute the emergency power supply wiring. Piper reported to the FAA that the wiring harness is installed in a way that may cause the wires to chafe against the rudder control cable.

“Use of the rudder flight control cable and the motion of the cable rubbing against the EPS wiring can wear through the rudder flight control cable insulation and cause an electrical path to ground,” the proposed rule states, adding that the electric current running through the rudder control cable can burn through the cable, eventually severing it. The FAA estimates a cost of $837 per aircraft to replace any damaged flight control cables, and another $3,620 to replace damaged emergency power supply wiring.

The AD would mandate compliance with Piper Aircraft Service Bulletin No. 1337 issued February 15, 2019, which includes inspection procedures as well as instructions for correcting the problem.

The FAA set a September 11 deadline to submit formal comments. This can be done online, or by mail to the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, D.C. 20590. Comments can also be submitted via fax to 202-493-2251.

The Seneca has been produced since 1972; the PA–34-220T was introduced in 1985 with Continental engines rated at 220 horsepower each. The original Seneca had 200-hp Lycoming engines.