Aeronautical Information Manual (AIM), page 540

Index   539 -- Page 540 -- 541

(a) Over flight.

(b) Use of markers.
(c) Weighted flags.
(d) Smoke bombs.

(e) Any colored rags.
(f) Dye markers.

(g) Kool-aid.

(h) Trees or tree branches.
2. It is difficult to determine the depth of snow
in areas that are level. Dropping items from the
aircraft to use as reference points should be used as a
visual aid only and not as a primary landing reference.
Unless your marker is biodegradable, be sure to
retrieve it after landing. Never put yourself in a
position where no visual references exist.

3. Abort landing if blowing snow obscures your

reference. Make your decisions early. Don't assume

you can pick up a lost reference point when you get


4. Exercise extreme caution when flying from
sunlight into shade. Physical awareness may tell you
that you are flying straight but you may actually be in
a spiral dive with centrifugal force pressing against
you. Having no visual references enhances this
illusion. Just because you have a good visual
reference does not mean that it's safe to continue.
There may be snow-covered terrain not visible in the
direction that you are traveling. Getting caught in a no
visual reference situation can be fatal.
h. Flying Around a Lake.
1. When flying along lakeshores, use them as a
reference point. Even if you can see the other side,
realize that your depth perception may be poor. It is
easy to fly into the surface. If you must cross the lake,
check the altimeter frequently and maintain a safe
altitude while you still have a good reference. Don't
descend below that altitude.
2. The same rules apply to seemingly flat areas
of snow. If you don't have good references, avoid
going there.

i. Other Traffic. Be on the look out for other
traffic in the area. Other aircraft may be using your
same reference point. Chances are greater of

colliding with someone traveling in the same
direction as you, than someone flying in the opposite
j. Ceilings. Low ceilings have caught many pilots
off guard. Clouds do not always form parallel to the
surface, or at the same altitude. Pilots may try to
compensate for this by flying with a slight bank and
thus creating a descending turn.
k. Glaciers. Be conscious of your altitude when

flying over glaciers. The glaciers may be rising faster
than you are climbing.

7-5-14. Operations in Ground Icing
a. The presence of aircraft airframe icing during
takeoff, typically caused by improper or no deicing of
the aircraft being accomplished prior to flight has
contributed to many recent accidents in turbine
aircraft. The General Aviation Joint Steering

Committee (GAJSC) is the primary vehicle for

government-industry cooperation, communication,

and coordination on GA accident mitigation. The

Turbine Aircraft Operations Subgroup (TAOS)
works to mitigate accidents in turbine accident
aviation. While there is sufficient information and
guidance currently available regarding the effects of
icing on aircraft and methods for deicing, the TAOS
has developed a list of recommended actions to
further assist pilots and operators in this area.
While the efforts of the TAOS specifically focus on
turbine aircraft, it is recognized that their recommen-
dations are applicable to and can be adapted for the
pilot of a small, piston powered aircraft too.
b. The following recommendations are offered:
1. Ensure that your aircraft's lift-generating
surfaces are COMPLETELY free of contamination
before flight through a tactile (hands on) check of the
critical surfaces when feasible. Even when otherwise
permitted, operators should avoid smooth or polished
frost on lift-generating surfaces as an acceptable
preflight condition.
2. Review and refresh your cold weather
standard operating procedures.

3. Review and be familiar with the Airplane
Flight Manual (AFM) limitations and procedures
necessary to deal with icing conditions prior to flight,
as well as in flight.

7-5-12 Potential Flight Hazards

Page 540 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   539 -- Page 540 -- 541