g. When landing at airports where volcanic ash has been deposited on the runway, be aware that even a thin
layer of dry ash can be detrimental to braking action. Wet ash on the runway may also reduce effectiveness of
braking. It is recommended that reverse thrust be limited to minimum practical to reduce the possibility of
reduced visibility and engine ingestion of airborne ash.
h. When departing from airports where volcanic ash has been deposited, it is recommended that pilots avoid
operating in visible airborne ash. Allow ash to settle before initiating takeoff roll. It is also recommended that
flap extension be delayed until initiating the before takeoff checklist and that a rolling takeoff be executed to
avoid blowing ash back into the air.
7-6-11. Emergency Airborne Inspection of Other Aircraft
a. Providing airborne assistance to another aircraft may involve flying in very close proximity to that aircraft.
Most pilots receive little, if any, formal training or instruction in this type of flying activity. Close proximity
flying without sufficient time to plan (i.e., in an emergency situation), coupled with the stress involved in a
perceived emergency can be hazardous.
b. The pilot in the best position to assess the situation should take the responsibility of coordinating the
airborne intercept and inspection, and take into account the unique flight characteristics and differences of the
category(s) of aircraft involved.
c. Some of the safety considerations are:
1. Area, direction and speed of the intercept;
2. Aerodynamic effects (i.e., rotorcraft downwash);
3. Minimum safe separation distances;
4. Communications requirements, lost communications procedures, coordination with ATC;
5. Suitability of diverting the distressed aircraft to the nearest safe airport; and
6. Emergency actions to terminate the intercept.
d. Close proximity, inflight inspection of another aircraft is uniquely hazardous. The pilot-in-command of
the aircraft experiencing the problem/emergency must not relinquish control of the situation and/or jeopardize
the safety of their aircraft. The maneuver must be accomplished with minimum risk to both aircraft.
7-6-12. Precipitation Static
a. Precipitation static is caused by aircraft in flight coming in contact with uncharged particles. These particles
can be rain, snow, fog, sleet, hail, volcanic ash, dust; any solid or liquid particles. When the aircraft strikes these
neutral particles the positive element of the particle is reflected away from the aircraft and the negative particle
adheres to the skin of the aircraft. In a very short period of time a substantial negative charge will develop on
the skin of the aircraft. If the aircraft is not equipped with static dischargers, or has an ineffective static discharger
system, when a sufficient negative voltage level is reached, the aircraft may go into "CORONA." That is, it will
discharge the static electricity from the extremities of the aircraft, such as the wing tips, horizontal stabilizer,
vertical stabilizer, antenna, propeller tips, etc. This discharge of static electricity is what you will hear in your
headphones and is what we call P-static.
b. A review of pilot reports often shows different symptoms with each problem that is encountered. The
following list of problems is a summary of many pilot reports from many different aircraft. Each problem was
caused by P-static:
1. Complete loss of VHF communications.
2. Erroneous magnetic compass readings (30 percent in error).
3. High pitched squeal on audio.

7-6-10

Potential Flight Hazards