Unapproved aircraft flight control modifications
Date issue released
Safety Issue Description

Some Cessna 206 parachuting aircraft, including VH-FRT, had their flight control systems modified without an appropriate maintenance procedure or approval. That increased the risk of flight control obstruction.

Issue number
Issue Status
Closed – Adequately addressed
Transport Function
Aviation: General aviation
Issue Owner
Civil Aviation Safety Authority (CASA)
Mode of Transport
Issue Status Justification

As a result of the safety action taken by the Civil Aviation Safety Authority and the Australian Parachute Federation, aircraft operators have increased awareness of this safety issue. Consequently, the ongoing safety risk is considered acceptable.

Proactive action
Action number
Civil Aviation Safety Authority
Action date
Action Status
Action description

The ATSB informed CASA about this safety issue during a meeting on 3 August 2015. In response, CASA issued airworthiness bulletin AWB 02-054 on 22 January 2016, titled Unapproved Modifications – Flight Controls, Structures and Systems, which stated:

CASA recommends that owners, operators and maintainers carry out a physical examination of their aircraft and the aircraft’s technical records to ensure:

  1. All modifications have been fully accomplished in accordance with the approved data for the modification.
  2. All unapproved and conflicting modifications are removed and the aircraft is returned to a serviceable and airworthy condition.
  3. The aircraft has the applicable flight manual supplement(s) for the associated manufacturer’s kit, or approved modification for the intended operation.
  4. The airworthiness and operation of the aircraft is not adversely affected by the incorporation of multiple STC’s [Supplemental Type Certificate] and other modifications.
  5. The continuing airworthiness requirements of each modification have been properly incorporated into the maintenance program.

CASA response to draft report on 27 March 2017

CASA has reviewed the current AWB 02-054 referenced in the report which was released in 2015 [2016] following this event. In consideration of the information provided in this ATSB report, CASA believes this document to be appropriate in its current form without further amendment required.

Australian Parachute Federation response

APF wrote to members regarding this directive. The first correspondence was on 9 September 2015 as soon as we were made aware of the potential issue, and again on 29 January 2016 as soon as the CASA Airworthiness Bulletin was released.

ATSB Response

The ATSB acknowledges the proactive safety action taken by CASA and the Australian Parachute Federation to address this safety issue.