Volume 3 GENERAL TECHNICAL ADMINISTRATION
CHAPTER 27 GROUND-DEICING/ANTI-ICING PROGRAMS
Section 1 General
3-2166 BACKGROUND. Section 1 of this chapter contains background
information on ground-deicing/anti-icing of aircraft. Section 2 provides policy,
direction, and guidance to Federal Aviation Administration (FAA) inspectors
for evaluation and approval of operator procedures.
Volume 6, Chapter 2, Section 15, of this handbook covers ground‑deicing/anti-icing
A. Requirements. There are essential differences in the ground-deicing/anti-icing
requirements of Title 14 of the Code of Federal Regulations (14 CFR) parts
135. For example, part
121 requires a complete deicing/anti-icing program that includes the training
and testing of all personnel involved in the ground-deicing/anti-icing process.
On the other hand, part
135 requires training and testing for pilots only. Additionally, if a part
135 operator chooses to use personnel other than pilots to assist in the
ground-deicing/anti-icing and verification process, then those individuals must
receive adequate and appropriate training. Part
125 requires testing for pilots only; however, other personnel involved
in the deicing/anti-icing process must receive adequate and appropriate training.
B. Deicing/Anti-icing Program. Parts
135 operators have the option to elect to meet the deicing/anti-icing requirements
121.629(c) and institute a full deicing/anti-icing program. Recognizing
that most inspectors will be required to inspect a variety of aircraft and operators,
this chapter will attempt to present the differences in a meaningful manner.
The inspector should become thoroughly familiar with the differences and requirements
in 14 CFR covering operations in icing conditions.
3-2167 RULE. The current regulations in parts
135 prohibit a takeoff when frost, ice, or snow (contamination) is adhering
to the wings, control surfaces, or propellers of an airplane (see §
125, § 125.221(a), and part
135.227(a)). Traditionally, the pilot in command (PIC) has been held responsible
for ensuring that critical surfaces of the aircraft are free of adhering frozen
contaminants before takeoff. By the winter of 1991, an analysis of air carrier
accidents led the FAA to conclude that many PICs had not been provided with
sufficient information to ensure that the aircraft is free of frost, ice, and
121 was amended in November 1992, and parts
135 were amended in January 1994 to provide specific rules for operating
(that is, taking off) in weather conditions when frost, ice, or snow could reasonably
be expected to adhere to the aircraft (ground-icing conditions).
A. General. Section
121.629(b) prohibits takeoff when contamination is adhering to critical
surfaces of an airplane or when takeoff would not be in compliance with §
121.629(c). The exception to that general rule is that the Administrator
may approve takeoff with “frost under the wing in the area of the fuel tanks.”
121.629(c) requires a detailed, comprehensive, deicing/anti-icing program
121 ground-deicing program) if a certificate holder is going to operate
“any time conditions are such that frost, ice, or snow may reasonably be expected
to adhere to the aircraft” (ground-icing conditions). Section
121.629(d) provides a means for a certificate holder to operate without
a program as required in §
121.629(c). If the operator does not have an FAA-approved deicing/anti-icing
121.629(c) prohibits an air carrier from “dispatch, release, or takeoff”
of an aircraft in ground-icing conditions.
NOTE: Principal operations inspectors (POI) may refer to Advisory Circular
120-60, Ground Deicing and Anti-icing Program, for a detailed description
of those elements that make up the program.
B. Provisions and Exceptions. An exception to the requirements
for a complete deicing/anti-icing program is contained in §
121.629(d), which provides that an air carrier is not required to have an
approved deicing/anti-icing program if an Outside-the-Aircraft Check (OTAC)
is completed within 5 minutes prior to beginning the takeoff. An OTAC must be
performed from outside the aircraft to ensure that “wings, control surfaces,
and other critical surfaces are free of frost, ice, and snow” when the certificate
holder is operating in ground-icing conditions. If a certificate holder chooses
to operate in accordance with §
121.629(d), the requirement for an OTAC must be documented in its operations
A. Pretakeoff Check. A pretakeoff check is a check of the aircraft’s
wings or representative aircraft surfaces for frost, ice, or snow within the
aircraft’s holdover time (HOT). This check is required when the certificate
holder operates (that is, intends to takeoff) in ground-icing conditions, the
aircraft has been deiced/anti-iced, and a HOT is established. This check is
accomplished within the HOT range and is normally accomplished by the flightcrew
from inside the cockpit. The pretakeoff check requires the flightcrew to check
the aircraft’s wings or representative aircraft surfaces for contamination as
well as to assess the current weather or other situational conditions. The pretakeoff
check is integral to the use of HOTs. If HOTs are used, at least one pretakeoff
check must be performed.
B. Pretakeoff Contamination Check.
1) A pretakeoff contamination check is a check that the flightcrew
and ground personnel conduct after the HOT has been exceeded to make sure that
the wings, control surfaces, and other critical surfaces, as defined in the
operator’s program, are free of frost, ice, and snow. The pretakeoff contamination
check must be completed within 5 minutes before beginning the takeoff. Operators
must have aircraft-specific procedures for use by flightcrew members and qualified
ground personnel while conducting the check to ensure that the aircraft’s wings,
control surfaces, and other critical surfaces remain free of frost, ice, or
snow when a HOT has been exceeded.
2) The pretakeoff contamination check must be conducted from
outside the aircraft for the following:
· Hard-wing airplanes with aft, fuselage-mounted, turbine-powered
NOTE: The check for these airplanes must include a tactile check of
selected portions of the wing-leading edges and the upper wing surfaces. Alternatives
to a tactile check may be approved only with concurrence of the manager of the
Air Transportation Division (AFS-200).
· For all other airplanes, unless the operator shows that the check
can be adequately accomplished from inside the airplane. POIs may refer to
120-60 for additional guidance.
C. OTAC. An OTAC is a check that must be accomplished from outside
the aircraft. Section
121.629(d) requires an OTAC of a certificate holder who operates in ground-icing
conditions without an approved part
121 ground-deicing/anti-icing program. For those operators without an approved
program, any time frost, ice, or snow may reasonably be expected to adhere to
the aircraft, an OTAC must be performed to ensure that the wings, control surfaces,
and other critical surfaces are free of contamination. An OTAC must occur within
5 minutes prior to beginning the takeoff.
D. HOT. HOT is the estimated time deicing/anti-icing fluid will
prevent the formation of frost or ice and the accumulation of snow on the treated
surfaces of an aircraft. HOT begins when the final application of deicing/anti-icing
fluid commences and expires when the deicing/anti-icing fluid applied to the
aircraft loses its effectiveness.
121 GROUND-DEICING/ANTI-ICING PROGRAM. In order for the certificate
holder to have an approved ground-deicing/anti-icing program that complies with
121.629(c), each operator’s ground-deicing/anti-icing program must cover
the following four areas as described in
· Management plan detailing operational responsibilities and procedures;
· Holdover timetables and procedures for their use;
· Procedures and responsibilities for aircraft ground-deicing/anti-icing,
pretakeoff check, and pretakeoff contamination check procedures; and
· Initial and recurrent ground training and/or testing for flightcrew
members and qualification for all other affected personnel, as applicable.
3-2171 MANAGEMENT PLAN. The operator should develop, implement, and
use a management plan to ensure proper execution of its approved deicing/anti-icing
program. The management plan should include operations and maintenance responsibilities
and identify the management positions that are responsible for ensuring that
all necessary elements of the deicing/anti-icing program are properly executed.
3-2172 HOLDOVER TIMETABLES AND THE PROCEDURES FOR THEIR USE.
A. Holdover Timetables. Each operator is required to develop,
and have available, holdover timetables for use by its personnel. In addition,
each operator must make its holdover timetables available for use in the cockpit.
These timetables are required to be supported by data acceptable to the Administrator.
Currently, the only acceptable data are those developed by the Society of Automotive
Engineers (SAE) and International Organization for Standardization (ISO). Aerospace
Recommended Practice (ARP) 4737, Aircraft Deicing/Anti-icing Methods, and ISO
11076, Aircraft Deicing/Anti-icing Methods on the Ground, contain the tables
that are currently considered acceptable for use by the operators to develop
NOTE: POIs may refer to
120-60 for additional guidance regarding the development of procedures
for increasing or decreasing determined HOTs.
B. Takeoff Within a HOT. If takeoff is conducted within the HOT,
121.629(c)(4) requires at least one pretakeoff check of the wings or representative
surfaces to be completed by the flightcrew within the HOT range prior to the
takeoff. Operator’s manuals should contain detailed procedures regarding the
use of the timetables in their operations. Section
121.629(c)(3) requires that the operator’s program contain procedures for
the flightcrew members to increase or decrease the determined HOT in changing
C. Takeoff After the HOT Is Exceeded. Under §
121.629(c), takeoff after the HOT is exceeded is permitted only if one or
more of the following actions have been taken:
1) A pretakeoff contamination check is made to ensure that wings,
control surfaces, and other critical surfaces, as defined in the certificate
holder’s program, are free of frost, ice, or snow.
2) It is otherwise determined by an alternative procedure, which
was developed by the operator and approved by the FAA (for example, wing-icing
sensors) that the wings, control surfaces, and other critical surfaces as defined
in the certificate holder’s program, are free of frost, ice, or snow.
3) The wings, control surfaces, and other critical surfaces have
been redeiced and a new HOT has been established.
135 GROUND-DEICING/ANTI-ICING TRAINING AND CHECKING RULE.
A. General. Section
135.227(a) prohibits a pilot from taking off in an aircraft that has “frost,
ice, or snow adhering to any rotor blade, propeller, windshield, wing, stabilizing
or control surface, to a powerplant installation, or to an airspeed, altimeter,
rate of climb, or flight attitude instrument system...” As evident by the use
of the term rotor blade, helicopters are subject to the regulation. There is
one exception to the regulation: Section
135.227(a) allows that “takeoffs may be made with frost under the wing in
the area of the fuel tanks if authorized by the Administrator.”
B. Provisions in Part
135 Ground-Deicing/Anti-icing Rule. Section
135.227(b) requires pilot training in accordance with §
135.341 if a certificate holder is going to operate (that is, takeoff) “any
time conditions are such that frost, ice, or snow may reasonably be expected
to adhere to the airplane...” (ground-icing conditions). In addition to pilot
135.227 requires a pretakeoff contamination check (see paragraph 3-2174).
Therefore, if the certificate holder is operating in ground-icing conditions,
it must have a pilot training program, which the pilot has completed, in accordance
135.341 and the pilot must conduct a pretakeoff contamination check. Exceptions
to the regulation that requires a pretakeoff contamination check when operating
in ground-icing conditions are as follows:
1) Administrator may approve an alternative procedure developed
by the operator to ensure the wings and control surfaces are free of contamination
(for example, wing-icing sensors); or
2) The operator may comply with the part
121 ground-deicing rule.
C. Important Differences Between the Part
121 Ground-Deicing Rule and the Part
135 Ground‑Deicing Rule. When compared to the part
121 ground-deicing regulation, the part
135 ground-deicing rule differs in the following respects:
1) Only pilot training and checking is required to be conducted
in accordance with §
2) The use of HOTs and holdover timetables when operators use
deicing/anti-icing fluids is only advisory in the part
135 ground-deicing rule.
3) A pretakeoff contamination check must be performed whenever
135 certificate holder is operating in ground-icing conditions.
3-2174 PRETAKEOFF CONTAMINATION CHECK. A pretakeoff contamination
check is a check to make sure the wings and control surfaces are free of frost,
ice, or snow. Section
135.227 requires that a pretakeoff contamination check be completed within
5 minutes prior to beginning the takeoff. It may be accomplished from inside
or outside the aircraft and may be visual, tactile, or a combination, as long
as the check is adequate to ensure the absence of contamination. The operator’s
POI must approve the pretakeoff contamination check procedures for each specific
type of aircraft operated by the certificate holder. Also, the operator’s OpSpec
A023 or A041, as applicable, must reference or describe the pretakeoff contamination
3-2175 APPROVALS FOR PART
135 OPERATORS. If a part
135 operator chooses to use a ground-deicing/anti-icing program (§
121.629(c)), the POI will issue OpSpec A023 to approve that program. If
135 operator chooses not to use a ground-deicing/anti-icing program, the
POI will issue OpSpec A042. The POI will authorize a pretakeoff contamination
check by issuing OpSpec A041, in accordance with §
135.227 (see Volume 3, Chapter 18, Section 3).
3-2176 APPLICABILITY OF THE PART
135 GROUND-DEICING RULE.
A. Certificate Holder Who Does Not Operate in Ground-Icing Conditions.
135 ground‑deicing rule does not apply to a certificate holder who does
not operate in ground-icing conditions. Under the regulation, ground-icing conditions
exist any time weather conditions are such that frost, ice, or snow may reasonably
be expected to adhere to the airplane. The certificate holder who does not operate
in ground-icing conditions is not required to train its pilots or develop pretakeoff
contamination procedures. Certificate holders who do not operate in ground-icing
conditions must be issued OpSpec A042.
B. Operators Who Use Only One Pilot in Their Operations. Operators
who use only one pilot in their operations (single-pilot operator) are not required
to comply with the manual and approved training requirements of § 135.21 or §
135.341. Therefore, single-pilot operators are not required to have an approved
pilot training program nor the additional training required by the part
135 ground-deicing rule. However, single-pilot operators must comply with
all the operational requirements of the part
135 ground-deicing rule. Those operational requirements include a pretakeoff
contamination check or an approved alternative procedure to the pretakeoff contamination
check described in its OpSpecs. The pilots of these types of operators will
need to demonstrate knowledge to operate in ground-icing conditions during the
initial and recurrent flight checks. A single-pilot operator will have an aircraft
specific description of the pretakeoff contamination check in OpSpec A023 or
A041, as applicable. If the operator does not operate in ground-icing conditions,
OpSpec A042 must be so documented and issued.
C. Helicopter Operations. Helicopter operations conducted under
135 are excluded from the additional training and pretakeoff contamination
check requirements of the part
135 ground-deicing rule. However, the regulation requires helicopter operations
to be conducted in accordance with the operating limitations of §
3-2177 TRAINING REQUIREMENTS OF THE PART
135 GROUND-DEICING RULE. If an operator is required to have an approved
training program, that training program must include pilot ground training relating
to deicing and anti-icing operations required by §
135.345 for initial, transition, and upgrade training and by §
135.351 for recurrent training and testing. These training requirements
must include procedures for operating airplanes during ground-icing conditions.
The operator must provide that training to its pilots and all other participating
personnel. The training must include at least the following elements:
A. Use of HOTs. In part
135 operations, HOTs are only advisory and serve as guidance to the pilot
in making takeoff decisions. If the operator uses the deicing/anti-icing fluids,
it must train its pilots in the use of HOTs.
B. Airplane Deicing/Anti-icing Procedures. Airplane deicing/anti-icing
procedures include responsibilities, requirements, and inspections and check
procedures for the pretakeoff contamination check or alternative procedures,
C. Communications. The operator must provide training for all
company personnel in communicating with all agencies involved in the deicing/anti-icing
process and the decisionmaking process.
D. Contamination. Aircraft surface contamination training includes
how to identify frost, ice, or snow, and how to locate critical areas. Training
should include an explanation of how small amounts of surface contamination
adversely affect aircraft performance and flight characteristics.
E. Deicing/Anti-icing Fluids. If the operator uses deicing/anti-icing
fluids, it must train its pilots, as well as any other participating personnel,
in the types and characteristics of deicing/anti-icing fluids.
NOTE: It is important that flightcrews do not use deicing/anti-icing
fluids unless they have been trained in the characteristics and effects of these
fluids on their operation.
F. Cold Weather Preflight Inspection Procedures. Training should
include procedures for cold weather preflight inspections.
G. Contamination Recognition. This aspect of training should
cover techniques for recognizing contamination on the aircraft for use during
both the preflight inspection and the pretakeoff contamination check.
NOTE: All training should be aircraft specific. When an operator has
different kinds of aircraft, any unique characteristics of these aircraft while
operating in ground-icing conditions should be covered.
NOTE: Other than part
135 single-pilot operators, who must have the pretakeoff contamination check
procedures described in their OpSpecs, both parts
135 operators must have documentation in their general manuals (GM) or flight
manuals (fm) for the procedures they intend to use to comply with their respective
deicing/anti-icing rule. These procedures may include descriptions of how and
by whom the pretakeoff contamination check will be accomplished, and how the
operator will comply with its approved deicing/anti-icing procedures. If an
operator elects to not fly when frost, ice, or snow may reasonably be expected
to adhere to the surface of an aircraft, that operator’s manuals should contain
specific guidance to that effect. This guidance should caution flightcrew members
that this operator does not have deicing/anti-icing procedures in effect and
does not authorize takeoff during ground-icing conditions.
NOTE: Inspectors should use this handbook section for background material
when reviewing those sections of operator’s manuals and procedures concerning
3-2178 SOURCES OF INFORMATION. The following publications (current
editions) may be useful to inspectors and operators for developing, reviewing,
and approving a ground-deicing/anti-icing program.
20-117, Hazards Following Ground Deicing and Ground Operations in Conditions
Conducive to Aircraft Icing. This AC contains useful background information
and also contains an extensive bibliography of related FAA and private sector
publications, training materials, and other deicing/anti-icing or related information.
120-60, Ground Deicing and Anti-icing Program. This AC contains information
on how operators may develop acceptable ground-deicing/anti-icing programs to
comply with §
135-16, Ground Deicing & Anti-icing Training & Checking. This AC
contains information on how operators may develop acceptable ground-deicing/anti-icing
programs to comply with §
120-58, Pilot Guide Large Aircraft Ground Deicing.
E. SAE Publications.
· Aerospace Material Specification (AMS) 1424, Deicing/Anti-Icing
Fluid, Aircraft, SAE Type I.
· AMS 1428, Fluid, Aircraft Deicing/Anti-Icing, Non Newtonian (Pseudoplastic),
SAE Types II, III, and IV.
F. SAE ARP 4737. This publication of the SAE contains holdover
tables and information on how they are developed as well as information on the
inspection of aircraft.
G. ISO Publications.
· ISO 11075, Aircraft Deicing/Anti-icing Fluids ISO Type I.
· ISO 11076, Aircraft Deicing/Anti-icing Methods on the Ground.
· ISO 11077, Aerospace Self Propelled Deicing/Anti-icing Vehicles
· ISO 11078, Aircraft Deicing/Anti-icing Fluids ISO Types II, III,
H. Computer-Based Instruction (CBI) Programs.
· Course 27019–Ground-deicing/Anti-icing for Airworthiness Inspectors.
· Course 27020–Ground-deicing/Anti-icing for Operations Inspectors.
I. Winter Operations Guidance for Air Carriers. This publication
contains a number of ACs and articles relevant to the topic. Specific publications
are listed here in case they need to be obtained and used separately:
20-73, Aircraft Ice Protection.
23.1419-2, Certification of Part
23 Airplanes for Flight in Icing Conditions.
65-15, Airframe and Powerplant Mechanics Airframe Handbook (see Chapter
91-6, Water, Slush, and Snow on the Runway.
91-13, Cold Weather Operation of Aircraft.
FAR Part 135 Icing Limitations.
· “Winter Operations,” Douglas Aircraft Company.
· Air Carrier Operations Bulletin (ACOB) 7-81-1, Aircraft Deicing
and Anti-icing Procedures.
· ACOB 7-82-2, Cold Weather Procedures.
· ACOB 8-83-1, Effects of Leading Edge Contamination on Aerodynamic
· ACOB 8-83-1, Turbojet Aircraft Engine Icing During Prolonged Operations
in Icing Conditions.
· FAA P-8740-24, Winter Flying Tips.
· “Deicing/Anti-icing Fluids Evaluation,” Boeing of Canada, De Havilland
Division Dash 8, all operator message No. 48.
· “Icing Precautions and Procedures,” Boeing of Canada, De Havilland
Division Dash 8, all operator message No. 49.
· “Wing Upper Surface Ice Detection MD 80,” Douglas Aircraft Company
Douglas Service, First Quarter, 1990.
· “Aerodynamic Effects of Deicing Fluids,” Boeing Airliner, Oct.-Dec.
· “Airplane Ground-deicing/Anti Icing,” Boeing Airliner, Oct.-Dec.
· “Deicing/Anti Icing,” Boeing Airliner, Oct.–Dec. 1989.
· “Winter Operations—An Update,” Boeing Airliner, Oct.-Dec. 1989.
NOTE: Numerous videotapes have been produced by manufacturers of deicing/anti-icing
products and by aircraft operators. Access to these tapes may be available through
the regional deicing/anti-icing coordinator or Flight Standards Training Division
RESERVED. Paragraphs 3-2179 through 3-2194.