background image

AIM 

3/21/24 

While the efforts of the TAOS specifically focus on turbine aircraft, it is recognized that their recommendations 

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. 

4. 

Protect your aircraft while on the ground, if possible, from sleet and freezing rain by taking advantage 

of aircraft hangars. 

5. 

Take full advantage of the opportunities available at airports for deicing. Do not refuse deicing services 

simply because of cost. 

6. 

Always consider canceling or delaying a flight if weather conditions do not support a safe operation. 

c. 

If you haven’t already developed a set of Standard Operating Procedures for cold weather operations, they 

should include: 

1. 

Procedures based on information that is applicable to the aircraft operated, such as AFM limitations and 

procedures; 

2. 

Concise and easy to understand guidance that outlines best operational practices; 

3. 

A systematic procedure for recognizing, evaluating and addressing the associated icing risk, and offer 

clear guidance to mitigate this risk; 

4. 

An aid (such as a checklist or reference cards) that is readily available during normal day

to

day aircraft 

operations. 

d. 

There are several sources for guidance relating to airframe icing, including: 

1. 

http://aircrafticing.grc.nasa.gov/index.html 

2. 

Advisory Circular (AC) 91

74, Pilot Guide, Flight in Icing Conditions. 

3. 

AC 135

17, Pilot Guide Small Aircraft Ground Deicing. 

4. 

AC 135

9, FAR Part 135 Icing Limitations. 

5. 

AC 120

60, Ground Deicing and Anti

icing Program. 

6. 

AC 135

16, Ground Deicing and Anti

icing Training and Checking. The FAA Approved Deicing 

Program Updates is published annually as a Flight Standards Information Bulletin for Air Transportation and 

contains detailed information on deicing and anti

icing procedures and holdover times. It may be accessed at 

the following website by selecting the current year’s information bulletins: 

https://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/deicing/. 

7

6

16.  Avoid Flight in the Vicinity of Exhaust Plumes (Smoke Stacks and Cooling Towers) 

a.  Flight Hazards Exist Around Exhaust Plumes. 

Exhaust plumes are defined as visible or invisible 

emissions from power plants, industrial production facilities, or other industrial systems that release large 

amounts of vertically directed unstable gases (effluent). High temperature exhaust plumes can cause significant 

air disturbances such as turbulence and vertical shear. Other identified potential hazards include, but are not 

necessarily limited to: reduced visibility, oxygen depletion, engine particulate contamination, exposure to 

gaseous oxides, and/or icing. Results of encountering a plume may include airframe damage, aircraft upset, 

7

6

16 

Potential Flight Hazards