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.
The ATSB notes and disagrees with the view of the Civil Aviation Safety Authority (CASA). CASA states that as the certifying state considers the Cessna 206 meets the certification standard and believes the design is safe, then they consider the aircraft meets the certification standard and the design is safe.
The ATSB disagrees and considers that the use of the cabin door as an emergency exit does not meet the certification requirements around emergency exits as the emergency exit is blocked by flap extension and the method of opening the door is not simple and obvious. There are documented accidents where there was significant delay in opening the cabin door or the door was not opened resulting in fatal injuries. However, given the view of CASA that no further action will be taken, the ATSB has closed the safety issue as not addressed.
The Australian Transport Safety Bureau recommends that the Civil Aviation Safety Authority takes safety action to address the certification basis for the design of the cabin doors in the Cessna 206, as wing extension beyond 10° will block the forward portion of the rear double door, significantly hampering emergency egress.
In response to AO-2020-010-SR-018, Safety Recommendation re C206 door configuration. CASA is not aware of any evidence to indicate that this aircraft does not meet the applicable certification standards as demonstrated by findings of compliance at the date of type certification by the FAA. The certification basis of this aircraft requires the proper functioning of exits for passenger egress to be demonstrated by tests as part of type certification (CAR 3.387). The FAA, as the State of Design, has investigated passenger egress from the rear cabin door and has not mandated any airworthiness actions. With the release of report AO-2020-010, CASA has issued Airworthiness Bulletin AWB 52-006 to communicate similar airworthiness information to that contained in EASA SIB 2020-16, Emergency Egress Difficulty, and NZ CAA CAN 25-003, Cessna 206 Emergency Egress Difficulty. AWN 52-006 Issue 1 has now been published on CASA’s website and a copy sent to all relevant subscribers (Copy attached). CASA will continue to monitor continued operational safety actions taken by the State of Design for the Textron Aviation C206 models and take appropriate actions. STCs issued by FAA and Transport Canada are automatically accepted by CASA under CASR Part 21. Therefore, a registered operator in Australia can purchase and incorporate STCs approved by these Authorities without further CASA approval if they elect to modify the forward door section of the rear cargo door configuration.
CASA was informed of the response from the FAA and advised they had nothing further to add.
