AIM Text
- Lasers have many applications. Of concern to users of the National Airspace System are those laser events that may affect pilots, e.g., outdoor laser light shows or demonstrations for entertainment and advertisements at special events and theme parks. Generally, the beams from these events appear as bright blue-green in color; however, they may be red, yellow, or white. However, some laser systems produce light which is invisible to the human eye.
- FAA regulations prohibit the disruption of aviation activity by any person on the ground or in the air. The FAA and the Food and Drug Administration (the Federal agency that has the responsibility to enforce compliance with Federal requirements for laser systems and laser light show products) are working together to ensure that operators of these devices do not pose a hazard to aircraft operators.
- Pilots should be aware that illumination from these laser operations are able to create temporary vision impairment miles from the actual location. In addition, these operations can produce permanent eye damage. Pilots should make themselves aware of where these activities are being conducted and avoid these areas if possible.
- Recent and increasing incidents of unauthorized illumination of aircraft by lasers, as well as the proliferation and increasing sophistication of laser devices available to the general public, dictates that the FAA, in coordination with other government agencies, take action to safeguard flights from these unauthorized illuminations.
- Pilots should report laser illumination activity to the controlling Air Traffic Control facilities, Federal Contract Towers or Flight Service Stations as soon as possible after the event. The following information should be included:
- UTC Date and Time of Event.
- Call Sign or Aircraft Registration Number.
- Type Aircraft.
- Nearest Major City.
- Altitude.
- Location of Event (Latitude/Longitude and/or Fixed Radial Distance (FRD)).
- Brief Description of the Event and any other Pertinent Information.
- Pilots are also encouraged to complete the Laser Beam Exposure Questionnaire located on the FAA Laser Safety Initiative website at http://www.faa.gov/about/initiatives/lasers/ and submit electronically per the directions on the questionnaire, as soon as possible after landing.
- When a laser event is reported to an air traffic facility, a general caution warning will be broadcasted on all appropriate frequencies every five minutes for 20 minutes and broadcasted on the ATIS for one hour following the report.
- When these activities become known to the FAA, Notices to Airmen (NOTAMs) are issued to inform the aviation community of the events. Pilots should consult NOTAMs or the Chart Supplement for information regarding these activities.
Source: FAA Aeronautical Information Manual · current edition · paragraph 7-6-13.
Research Notes
AIM 7-6-13 covers Carburetor Ice — the often-misunderstood induction system ice that can form even on warm days.
The paradox: Carburetor ice can form when OAT is between +20°F and +70°F with high humidity. The Venturi effect in the carburetor causes a pressure and temperature drop that can freeze moisture in the induction air — even when ambient temperature is well above freezing.
Symptoms:
- Loss of power without other apparent cause
- Engine roughness
- Difficulty maintaining power
- RPM drop or throttle response sluggishness
Response: Apply full carburetor heat. The hot air melts the ice. Engine may run rough as ice melts, then smooth out. Continue with carb heat ON until conditions warrant returning to cold air.
When carb heat is more important:
- Descent at reduced power (Venturi effect strongest at idle/low power)
- Cruise in humid air, especially 40-60°F
- Approach
Fuel-injected engines: Don't have a carburetor and don't experience carb ice. But they can experience induction air icing — different mechanism, requires "alternate air" rather than carb heat.
Reference: AC 20-113 (Pilot Precautions and Procedures to be Taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems); AIM 7-6-13.