Cessna 206 Quick Exit Door Modification

Coast Dog Aviation, a well-known western Canadian maintenance organization, recently announced that a Transport Canada supplemental type certificate (ST) had been issued for the installation of a Cessna 206 cargo door modification, which provides a significant increase in safety. This modification allows passengers to quickly exit the aircraft in an emergency by opening the aircraft’s forward cargo door, regardless of flap position. In addition, the modification enables Cessna 206s to be operated with a six-seat configuration, without altering the normal operation and functionality of the door. This STC eliminates the need to install the Cessna Service Kit SK206-40, which was introduced in 1991 to help those onboard a 206 to operate the aft cargo door from inside the aircraft at night.

The product, known as the arc Quikex, was developed by the Airworthiness Resources Corporation (arc), which owns the STC. Coast Dog Aviation has been approved for the professional installation of the kit, while also being responsible for sales and technical support.

Originally developed in the early 1960s, the Cessna 206 Stationair proved to be a popular and versatile aircraft with private and commercial operators. The aircraft remains in production today, with thousands of examples built and flying around the world. In addition to wheels, 206s can easily be configured to operate on skis, floats or amphibs. Despite its versatile, robust design, several incidents involving Canadian 206 floatplanes have resulted in fatalities where occupants were unable to exit the aircraft. A number of factors made it difficult to exit the aircraft in an emergency, especially when inverted and submerged under water. For example, extended flaps blocked the cargo doors (emergency exit) from opening. Also, from inside the aircraft, opening the doors was not a simple and obvious task. With the introduction of the current 206H model, Transport Canada determined that the cargo doors could not be considered an emergency exit and certified the aircraft with a limit of five occupants, thereby opening space for passengers in rear seats to egress through the front exit.
In light of these problems inherent to the 206’s cargo doors design, the arc team set itself the goal of developing a solution. The team came up with several ideas. For example, one idea was to have the rear cargo door open without the need to open the forward cargo door, but that presented a new risk. If the rear cargo door were inadvertently opened in flight, it would open into the airflow, causing it to be ripped off and embedded into the aircraft’s tail section. Another idea was to modify the flaps in such a way that the door could still be opened when the flaps were in a lowered position, but that would alter the aircraft’s flight characteristics. Finally, arc came up with a suitable solution: hinging the forward cargo door window. This allowed the door to open despite extended flaps. It also provided an emergency exit on the opposite side of the entry door, providing a way of escape in any crash attitude. Opening the door would also be simple and obvious, as only one factory handle had to be operated.

The initial prototype was first tested last year on 25 March. As part of the certification process, flight tests were carried out in various configurations, such as steep turns, high speed manoeuvres and Vne. The results of the tests showed that the modification caused no vibrations or wind noise, and no change to flight characteristics. Extensive egress testing was conducted with full flaps. The final tests, witnessed by transportation engineers from Transport Canada, showed that naïve passengers could easily and quickly exit the aircraft through the forward cargo door.
As part of the modification kit, photoluminescent placards show passengers how to open either one or both cargo doors in the dark, taking in consideration that the aircraft may be inverted.

A photoluminescent placard and rubber guard are also installed on the starboard flap’s inboard rib for extra safety.

In August last year, arc was awarded a Transport Canada STCfor the installation of the forward cargo door split window modification. More recently, European Union Aviation Safety Agency (EASA) and Federal Aviation Administration (FAA) STCs have been secured for the kit, making the ARC Quikex an approved, worldwide solution. According to Coast Dog Aviation, it takes about 16 hours to install the kit (excluding final finish) when someone is doing it for the first time. It must be noted that the Canadian airworthiness directive (AD) CF-2020-10 requires many Cessna 206 operators to install the Cessna Service Kit  SL206-40

by October this year. This kit costs about US$4,000 and does little to improve safety and does not allow six seats to be used. As mentioned in the opening paragraph, with the Quikex kit installed, SL206-40 is not required, and one would benefit from significantly increased safety and be allowed to operate with six seats.

For further information, please visit www.coastdogaviation.com and www.quikex.online