Applies To Certain PA-18 And PA-19 Model Airplanes

The FAA has posted a Special Airworthiness Information Bulletin (SAIB) for an airworthiness concern involving some Piper PA-18 and PA-19 airplanes. The affected aircraft have magneto toggle switches located on the left cabin panel. The FAA has found that the magneto toggle switches can be inadvertently turned off when operating nearby controls and cause a loss of power during takeoff and landing. This SAIB also provides guidance on where to locate and/or replace the magneto toggle switches to reduce the likelihood of their inadvertent shutoff in flight.

The FAA has received reports of pilots inadvertently shutting of magnetos in flight. In August 2011, the inadvertent shutoff of magneto toggle switches during a takeoff resulted in substantial damage to the airplane. In September 2011, the inadvertent shutoff of magneto toggle switches during landing resulted in serious personal injury and substantial airplane damage. In each incident, the inadvertent shutoff of the magneto toggle switches was attributed to the operation of the nearby trim control – located just beneath the magneto toggle switches on the left cabin panel.

To reduce the possibility of inadvertent shutoff of magnetos in flight, the FAA recommends that Piper PA-18 and PA-19 Model airplanes have the magneto toggle switches located on the left cabin panel relocated and/or replaced as follows:

• Relocate the magneto toggle switches from the left cabin panel to the airplane’s wing root or instrument panel, not near the fuel primer. As an option, the relocated toggle switches can be replaced with a keyed or non-keyed rotary magneto switch.
• If the magneto toggle switches are not relocated, replace the magneto toggle switches on the left cabin panel with a non-keyed rotary magneto switch. Because of the protruding key, a keyed rotary switch is not recommended in this location. After magneto toggle switch relocation and/or replacement, we recommend performing an engine run to verify proper engine operation, and then after allowing the engine to reach operating temperatures, perform a normal magneto check.

The FAA says that the condition does not currently warrant the issuance of an AD.

FMI: SAIB