Bombardier DHC-4 and DHC-5 - Service Difficulty Alert

AL 1999-02
16 March 1999

Weight and Balance Procedures

As part of an investigation of an aircraft with unusual handling characteristics, Bombardier (formerly de Havilland) conducted a study of aircraft weight and balance procedures for high wing aircraft. The study concluded that the use of wing jacks during weighing procedures for high wing aircraft can potentially result in centre of gravity (cg) errors as large as 2 to 3% of the Mean Aerodynamic Chord (MAC). These results are applicable to the DHC-4 and DHC-5 series aircraft.

To eliminate the potential for significant cg errors to occur during weight and balance checks, Transport Canada recommends that operators of DHC-4 and DHC-5 series aircraft:

  1. Review the Weight and Balance Handbook of each aircraft and determine the weighing method used during the last weight and balance check;
  2. If wing jacks were used or if it cannot be confirmed that bottle jacks or platform scales were used, perform a weight and balance procedure on the aircraft using bottle jacks or platform scales at the next convenient maintenance opportunity; and
  3. Use bottle jacks or platform scales during all future weight and balance checks.

For further information contact a Transport Canada Centre, or call Mr. Ian McLellan, Continuing Airworthiness, Ottawa, telephone (613) 952-4362, facsimile (613) 996-9178 or e-mail

For Director, National Aircraft Certification

B. Goyaniuk
Acting Chief, Continuing Airworthiness