Cessna 206 aircraft that feature a rear double cargo door do not meet the aircraft certification basis for the design of cabin exits. Wing flap extensions beyond 10° will block the forward portion of the rear double cargo door, significantly hampering emergency egress. This has previously resulted in fatalities.
Response by the Civil Aviation Safety Authority
On the 22 April 2021, the Civil Aviation Safety Authority provided the following response.
The ATSB have not provided evidence to support their claim that the design does not meet the certification basis. The Cessna 206 has a valid Type Certificate, issued by the FAA, with the aircraft meeting the required airworthiness requirements including those for exits and egress. CASA recommends that the statement that the aircraft does not meet the certification is not correct.
ATSB comment in response
The ATSB acknowledges that the Cessna 206 was certified by the FAA however, it is also noted that emergency doors for this aircraft type are required to be clear, unobstructed and capable of being opened with a simple and obvious method. The fact that extension of more than 10° of flap will block the cargo door, requiring a complicated sequence to permit egress, is not considered to meet the certification intent.
The ATSB also notes that independent action has been taken by other regulatory bodies to address the identified safety issue around emergency egress. There are several modifications available, that have received or are going through the process to receive supplementary type certificate approvals, which will significantly improve emergency egress for passengers in the rear of the aircraft. However, at the time of writing, none of these modifications were mandatory.