Just as training is required for any system in an aircraft, AOA indicators have training  considerations also. A more comprehensive understanding of AOA in general should be the goal  of this training along with the specific operating characteristics and limitation of the installed  AOA indicator. Ground and flight instructors should make every attempt to receive training  from an instructor knowledgeable about AOA indicators prior to giving instruction pertaining to  or in airplanes equipped with an AOA indicator. Pilot schools should incorporate training on  AOA indicators in their syllabi whether their training aircraft are equipped with them or not.  Installation of AOA indicators not required by type certification in GA airplanes has recently  been streamlined by the FAA. The FAA established policy in February 2014 pertaining to non- required AOA systems and how they may be installed as a minor alteration, depending upon  their installation requirements and operational utilization, and the procedures to take for  certification of these installations. For updated information on this, please reference the FAA  webpage at  http://www.faa.gov.  While AOA indicators provide a simple visual representation of the current AOA and its  proximity to the critical AOA, they are not without their limitations. These limitations should be  understood by operators of GA airplanes equipped with these devices. Like advanced  automation such as autopilots and moving maps, the misunderstanding or misuse of the  equipment can have disastrous results. Some items which may limit the effectiveness of an  AOA indicator are listed below:  Pilots of GA airplanes equipped with AOA indicators should contact the manufacturer for  specific limitations applicable to that installation.  • Calibration techniques  • Probes or vanes not being heated  • The type of indicator itself  • Flap setting  • Wing Contamination  Instrument Flying Handbook Addendum: Angle of Attack Indicators April 2015  3 