Regulatory Brief -- Inconsistent FAA interpretation leads to problems with use of hand-held GPS units in aircraft

Regulatory Brief

Inconsistent FAA interpretation leads to problems with use of hand-held GPS units in aircraft

The issue:

The FAA�s definition of an "installation" as applied to hand-held GPS units in an aircraft is vague and poorly explained. Due to the rising popularity of the use of these units, FAA field inspectors are faced with the task of interpreting the FAA�s vague definition in determining when a hand-held GPS unit is "installed" in the aircraft and when it is not.

The importance to our members:

Because of the lack of policy and guidance material regarding the FAA�s definition of the installation of a hand-held GPS unit in an aircraft, FAA field inspectors are routinely misinterpreting the FAA�s policy. For example, in one region of the United States a FAA inspector may state that the use of Velcro to attach a hand-held GPS unit to the yoke constitutes an installation and requires the filing of a FAA form 337. Meanwhile, in another region of the United States an inspector may state that as long as no tools are needed to remove the hand-held unit from the aircraft, no form 337 or field approval is required. These inconsistent interpretations often cause users of hand-held GPS units to complete unnecessary paperwork or undergo unneeded bureaucratic procedures to legally use their hand-held GPS units on board their aircraft. If nothing else, these misinterpretations and misapplications of FAA policy can cause considerable aggravation to users of hand-held GPS units.

Significant provisions:

  • At present there are two publications that provide guidance to pilots and FAA inspectors regarding hand-held GPS units. These are AC-91-21 Use of Portable Electronic Devices Aboard Aircraft, and RTCA paper number 379-93/TMC-99. Neither publication gives a clear explanation of what constitutes the installation of a hand-held GPS unit.
  • AOPA is receiving a steady number of contacts from members across the country on this issue.
  • Most member complaints involve a FAA inspector�s incorrect characterization of the use of thumbscrews to mount a hand-held GPS unit to the yoke, a suction cup to mount an antenna in the windscreen, or connection of a power lead to the aircraft�s cigarette lighter. These actions are most often characterized as "installations" requiring the filing of FAA form 337.
  • Conversations with the FAA Aircraft Certification and Aircraft Maintenance Division reveals agreement that any receiver or antenna mounting device that can be removed from an aircraft without the use of tools or a power lead connected to the aircraft�s cigarette lighter, does not qualify as an installation requiring a field approval.

AOPA position:

AOPA receives a steady number of member contacts on this issue. This serves as an indicator that FAA guidance material currently being used to clarify the FAA�s policy regarding the "installation" of a hand-held GPS unit is failing to provide adequate guidance to inspectors in the field. To address this concern and create consistency and accuracy in the interpretations, AOPA recommends that the FAA reevaluate its use of the current advisory material and implement common-sense guidelines into an official policy statement that clearly defines what constitutes the installation of a hand-held GPS unit in an aircraft.

Status:

On March 3, 1999, AOPA sent a letter to the manager of FAA Aircraft Maintenance Division, asking that the FAA reevaluate its use of current advisory material and issue a clarification of the FAA�s policy on this issue. We have yet to receive a formal response. This matter was brought before senior FAA management at a recent General Aviation Coalition meeting. AOPA is planning to call a meeting between the FAA Flight Standards and Aircraft Certification divisions in the near future to "hammer out" a new policy.

Related documents:

AOPA letter to FAA manager of Aircraft Maintenance Division, March 3, 1999