Commercial and Business Aviation Policy Letter (CBAPL) No. 58


Aircraft Critical Surface Contamination (ACSC) - National Policy, Procedures and Guidelines

File Number

AARC 5002-32-2




This Policy Letter applies to all ground and fligth operations personnel, holders of Canadian aviation documents and the operator of any Canadian registered aircraft. Section 540.2 of the Air Regulations and amendments to Air Navigation Orders Series VII, Nos. 2, 3 and 6 were published in Part II of the Canada Gazette, on November 21, 1990. This legislation affects the way any aircraft can now be legally operated when exposed to the risk of ACSC and affects the training programmes for Canadian commercial operators. Where foreign aircraft are involved, they must comply with Section 540.2 of the Air Regulations.

This programme, the revised legislation and its impact on the aviation community must be implemented in a judicious an equitable manner.


The purpose of this Policy Letter is to provide National policy procedures and guidelines to ensure a national standard for monitoring operations, when conditions are forecast or exist that create ACSC and addresses the regulatory process to be followed in the event of non-compliance with this legislation.


  • National Monitoring Guidelines applicable to all classes of operations (private, corporate, state and commercial);
  • Training and knowledge requirements pertaining to ACSC and particularly section 540.2 of the Air Regulations;
  • An information/feedback reporting system.


Civil Aviation Inspector Responsibilities

  • Complete the initial and recurrent training outlines under Inspector Training;
  • Promote compliance with s. 540.2 of the Air Regulations and the applicable Series VII, Air Navigation Orders;
  • Conduct ACSC surveillance as required;
  • Complete a Ramp Check inspection form for each aircraft checked where potential ACSC infraction occurs;
  • When a verbal warning has been given to the pilot-in-command, the advisory is ignored and the flight is intended to depart, the Inspector shall:
    • detain the aircraft
    • initiate the compliance process by completing a Preliminary Investigation report;
    • secure and ensure continuity of evidence;
    • provide copies of the completed reports to the Regional Director Air Carrier; and
    • forward the evidence, statements if available and completed reports to the applicable Regulatory Compliance Branch.

Civil Aviation Inspector Training

  • Complete the Transport Canada Aircraft Critical Surface Contamination (ACSC) training programme including video, booklet and the open book examination questions provided.
  • Review and self-study section 540.2 of the Air Regulations, Air Navigation Orders Series VII, Nos. 2, 3 and 6 as applicable.


  • Transport Canada Air Carrier Advisory Circular Number 18;
  • Aeronautical Information Publication (AIP) - Airmanship Section 2.2 Winter Operations;
  • Policy Letter 45 titled Surface Contamination Training dated September 28, 1990.

Operational Procedures

When monitoring flight operations on an airport or aerodrome, advise and coordinate communications with the appropriate ATS unit chief beforehand.

  • Ensure that the aircraft is inspected and/or decontaminated before further flight.

Inspector in Another Aircraft

  • As per above - radio communication.

Inspector as a Passenger

  • Whenever possible, ask to be assigned or choose passenger seats that give a clear view of the wing(s).
  • Should the aircraft push-back/start-up occur while the wings are still contaminated, the Inspector should, where time permits, bring the contamination to the attention of a flight attendant or in his/her absence a flight crew member. Note: In some instances de-icing procedures and anti-icing procedures are accomplished at a site remote from the terminal area.
  • If the Inspector feels that the aircraft is about to depart with ACSC, he/she shall identify themselves by licence credentials and inquire in a tactful manner about observed conditions and decontamination options.
  • If the pilot-in-command does not make the required inspection or intends to depart with a contaminated aircraft the Inspector shall proceed to the cockpit, identify him/herself with credentials and request that the aircraft not take-off until it is decontaminated, pursuant to Aeronautics Act.
  • Every effort must be made to be discrete, yet firm and keep the cockpit climate as rational as possible.
  • Ensure that the aircraft is inspected and/or decontaminated before further flight.


Programme Implementation

Traditionally in the spring, fall and winter as part of the Regional Master Surveillance Plan (RMSP), resources should be directed to monitoring of ACSC concerning all aircraft operations. Activities can be broken down under the following:

Major Airports Where Deicing Services Are Available

  • When ACSC conditions are forecast, Inspectors should be assigned airport surveillance duties at major airports. The Airport Manager(APM) and ATS shall be advised accordingly.
  • When Inspectors are assigned duties outside the Regional/District office, they are expected to conduct special surveillance for ACSC.
  • Conducting inspections from passenger jetways, or on the apron/ramp area may be required where possible.
  • The Inspector(s) assigned these inspection duties should have direct contact with the ATS facility by the appropriate VHF Ground Control frequency or cellular phone.
  • Holdover times of departing aircraft should be closely monitored. Ideally, an aircraft is de-iced/anti-iced just prior to take-off.
  • Available data, the types of de-icing fluids currently available in Canada and the possible combinations, make it difficult to determine a maximum holdover time between de-icing and actual departure.

Inspectors should use their knowledge of aircraft types, the varied operations and meteorology to help determine when there is a risk of ACSC.

When ACSC conditions exist and aircraft are delayed for take-off, Inspectors should closely monitor the ground operations.

Ground Icing Conditions at Airports

When ACSC conditions exist the following plan will be implemented:


  • Where an Inspector observes that an aircraft has exceeded the recommended hold-over times in freezing precipitation conditions or appears to have snow, ice of frost adhering to its critical surfaces, he/she will advise the pilot-in-command of the circumstances. This is normally done through the ATC facility.
  • Where an Inspector is certain in his/her judgement that an unsafe condition exists, he/she will invoke his/her regulatory powers under paragraph 8.7(1)(d) of the Aeronautics Act and detain the aircraft until it has been made safe for flight.


  • When congestion or line-ups occur at the end of the departure runway and holdover times are being exceeded, Air Traffic Control will be directed to implement departure restrictions and other appropriate mesures to reduce delays between the time the aircraft is de-iced and take-off.


  • When PHASE(S) I and II are ineffective, ATS will be directed to deny clearances, and, if necessary, the Inspector will obtain the assistance of the RCMP or airport personnel to prevent take-off.

Remote Operations

Monitoring of air carriers, corporate operators and general aviation that arrive and depart from remote airports and aerodromes when ACSC conditions are forecast should address the following:

  • Inspectors conducting external office functions during these periods are expected to conduct special surveillance for ACSC.
  • Conducting frequent ramp checks and aircraft inspections may be required.
  • The Inspector(s) assigned theses inspection duties should be in contact with the ATS facility by portable FM/VHF or cellular phone.
  • Aircraft departure delays should be closely monitored.

Inspector Equipment Required for ACSC Responsibilities

The following should be the minimum equipment required for Inspectors involved in ACSC surveillance:

  • (an airside vehicle operation permit will be required);
  • Cellular phone, or a VHF portable tied to the ATS appropriate Ground Control radio frequency.

Communications and Feedback Reporting System

An ACSC OPI should be appointed in each region. This person should be responsible for:

  • ACSC information and liaison, advising regional Inspectors and Managers of any significant changes or developments.
  • Coordination with air carrier ACSC programmes.
  • Maintaining a library/chronology of :
    • policy and guidelines information;
    • regulatory information;
    • accident/safety research data;
    • advisory circulars (TC & FAA);
    • TC's "When in Doubt" video and associated information;
    • surveillance/occurrence reports.
  • Preparation and coordination of an ACSC surveillance plan and introduction of this plan when ACSC conditions are likely to occur or are forecast.

Delegated Authority

This Policy Letter is designated AARCB 1991 No. 58.

A.J. LaFlamme
Flight Standards
(Air Carrier)