Chapter 4 - Preventative Measures and Deicing Procedures

Summary- Chapter 4

  • The best method of ensuring that an aircraft is clean of contamination is by preventing the contamination from collecting in the first place.
     
  • Measures include hangers and wing covers.
     
  • Manual methods to remove frozen contamination are brooms, brushes, ropes and scrapers.
     
  • Heat from a portable forced air heater can effectively remove frost and ice from critical surfaces.
     
  • Polishing frost is not considered an acceptable method of preparing an aircraft for flight.
     
  • Proper fluid coverage is absolutely essential for proper fluid performance. It is imperative that the personnel applying the fluid are properly trained and that a consistent fluid application technique is utilized.
     
  • An aircraft may be deiced by any suitable method such as hangering or manual methods.
     
  • Deicing is normally accomplished using heated water or solutions of heated water and FPD fluids, often followed by anti-icing using cold, rich solutions that have a lower freezing point.
     
  • Deicing and anti-icing with FPD fluids may be performed as a one-step or two-step process.
     
  • For aerodynamic reasons, ensure that the deicing and anti-icing procedures are conducted in a symmetrical fashion.
     
  • Generally, the fuselage should be de-iced and anti-iced from the top down.
     
  • On many aircraft, deicing of the wing begins at the leading edge wing tip, sweeping in the aft and inboard direction. This procedure avoids increasing the snow load on outboard wing sections.
     
  • For turbo-jet engines, FPD fluids should not be used for deicing internal components.
     
  • Particular care should be exercised for the APU inlet because fluid ingestion could cause an APU runaway condition, flameout or, in an extreme case, an APU rotor burst which often results in a fire.
     
  • Follow procedures to protect the aircraft during deicing/anti-icing with the main engines running.
     
  • The Deicing Operator must routinely provide information to the pilot and advise of any problems or malfunctions.
     
  • Critical surface inspections should be performed immediately after final application of the anti-icing fluid.
     
  • As required by regulations, immediately prior to take-off, a pre-take-off inspection shall be made to determine whether frost, ice or snow is adhering to any of the aircraft critical surfaces, except where the operator has established a program in accordance with the Ground Icing Operations Standards and complies with that program.
     
  • Take-off may occur after holdover time has been exceeded only if a pre-take-off contamination inspection is conducted and it is determined that critical surfaces are not contaminated.
     
  • The SAE has not published documents that support the use of FPD fluids on Rotorcraft.
     
  • Recent technologies employ such scientific principles as: the latent heat of fusion; the sensing of vibrating elements; the employment of ultrasonic sensors; and the use of infrared (IR) detection cameras.
     
  • Transport Canada, Commercial and Business Aviation Branch, Operational Standards Division (AARXB), should be contacted to discuss any proposal to use these new systems for commercial aircraft ground icing operations.