Unapproved equipment installation and/or configuration of the aeroplane - Civil Aviation Safety Alerts (CASA) No. 2013-01

Owners and maintainers of aeroplanes that have an extensive and convoluted technical history

Issuing Office: National Aircraft Certification Branch
Document No. : CASA -2013-01
File Classification No. : Z 5000-35
Issue No. : 01
RDIMS No. : 8004398
Effective Date: 2013-04-24


The purpose of this Civil Aviation Safety Alert (CASA) is to advise the aviation community that extra attention is necessary when reviewing the technical records of aeroplanes that may have an extensive and convoluted historical past, to ensure proper compliance.


In March 2012, the Office of the Chief Coroner of British Columbia produced the following report, "Death Review Panel: Four Fatal Aviation Accidents Involving Air Taxi Operations on British Columbia’s Coast". A copy of this report can be reviewed at the following web address: http://www.pssg.gov.bc.ca/coroners/publications/docs/death-review-panel-aviation.pdf.

The coroner’s report discusses one accident involving a DHC-2, "Beaver" aeroplane where the seat and restraint system installation failed.

The aeroplane’s collision with water caused the pilot's seat to sustain a structural failure, which rendered the seat-belt restraint system ineffective, thus contributing to the pilot’s injuries. Consequently, Transport Canada Civil Aviation (TCCA) requested that the aeroplane Type Certificate Holder (TCH), Viking Air Limited, conduct a review of the seat assembly as installed in the accident aeroplane to determine if there was a structural integrity issue.

The TCH concluded that the pilot’s seat configuration/assembly was a combination of a military pilot seat pedestal, which is approved in the civilian DHC-2 aeroplane, and a military cabin seat pan with tilting seat back, which is also approved. The cabin seat pan with tilting seat back is specifically designed for the mid-cabin location. The tilting seat back provides for egress of the rear seated passengers. Although these two units are approved separately, one specifically for the pilot’s position and the other for the mid cabin, the combining of these two units is not a configuration approved by the TCH. The TCH has stated that they are not aware of any document, domestic or foreign, that has approved the installation of this configuration/assembly as installed in the accident aeroplane. TCCA is also not aware of any document, domestic or foreign, that has approved the installation or configuration as installed in the accident aeroplane. Accordingly, such a configuration is unapproved.

The former TCH, DeHaviland Canada Ltd., issued a relevant Service Bulletin (SB) 2/39, dated August 31, 1984. The SB notified owners of accident/incident reports that have revealed the use of unapproved seat configurations. SB 2/39 identifies a list of checks to be accomplished relevant to the seat installations.

The attached figure is a similar seat to that of the accident aeroplane. This configuration is not approved.


Recommended action:

  1. TCCA recommends that owners and operators be extra attentive when reviewing technical records involving older aeroplanes. There is a possibility of unapproved seat configurations, and/or other equipment/installations, in aeroplanes that have an extensive and convoluted history. If there are questionable installations, configurations, repairs, or parts found on your aeroplane during review of technical records or performance of maintenance, do not dismiss the possibility that they may be unapproved. TCCA recommends that owners and operators carefully investigate these discrepancies and promptly rectify them as required.
  2. TCCA also recommends owners and operators of the DHC-2 aeroplane to incorporate the recommendations of SB 2/39. The checks identified in the SB could also be adapted to other similar aeroplanes.

Defects, malfunctions and failures occurring on aeronautical products are to be reported to Transport Canada, Continuing Airworthiness in accordance with CAR 521 mandatory Service Difficulty Reporting requirements.

Contact office:

For more information contact a Transport Canada Centre; or Marcel Gauthier, Continuing Airworthiness, Ottawa, at 613-952-4357, facsimile 613-996-9178, or e-mail CAWWEBFeedback@tc.gc.ca

For the electronic version of this document, please consult the following Web address www.tc.gc.ca/civil-aviation-safety-alert

For the Director, National Aircraft Certification


Philip Tang
Acting Chief, Continuing Airworthiness

The Transport Canada Civil Aviation Safety Alert ( CASA ) is used to convey important safety information and contains recommended action items. The CASA strives to assist the aviation industry's efforts to provide a service with the highest possible degree of safety. The information contained herein is often critical and must be conveyed to the appropriate office in a timely manner. The CASA may be changed or amended should new information become available.