AMC 27.805(c) Flight crew emergency exits

ED Decision 2018/007/R

This AMC supplements FAA AC 27.805.

(a)     Explanation

To facilitate a rapid escape, flight crew underwater emergency exits should be designed for use with the rotorcraft in both the upright position and in any foreseeable floating attitude. The flight crew underwater emergency exits should not be obstructed during their operation by water or floats to the extent that rapid escape would not be possible or that damage to the flotation system may occur. This should be substantiated for any rotorcraft floating attitude, upright or capsized, and with the emergency flotation system intact and with any single compartment failed. With the rotorcraft capsized and floating, the flight crew underwater emergency exits should be usable with the cabin flooded, and the markings required to enable occupants to escape in darkness should continue to function when the rotorcraft is capsized and the cabin is submerged.

(b)     Procedures

(1)     It should be shown by test, demonstration or analysis that there is no interference with the flight crew underwater emergency exits from water or any stowed or deployed emergency flotation devices, with the rotorcraft in any foreseeable floating attitude.

(2)     Flight crew should be able to reach the operating device for their underwater emergency exit, whilst seated, with restraints fastened, with seat energy absorption features at any design position, and with the rotorcraft in any attitude.

(3)     Likely damage sustained during a ditching should be considered.

(4)     It is acceptable for the underwater emergency exit threshold to be below the waterline when the rotorcraft is floating upright, but in such a case, it should be substantiated that there is no obstruction to the use of the exit and that no excessive force (see FAA AC 29.809) is required to operate the exit.

(5)     It is permissible for flight crew to be unable to directly enter life rafts from the underwater flight crew emergency exits and to have to take a more indirect route, e.g. by climbing over a forward flotation unit. In such a case, the feasibility of the exit procedure should be assessed. Handholds may need to be provided on the rotorcraft.

(6)      CS 27.807(b)(3) requires emergency exit markings to be provided and enable the emergency exit to be located and operated in darkness. Furthermore, CS 27.805(c) requires these illuminated markings to continue to function if the cabin becomes submerged. This should be shown by test, demonstration or analysis.

(7)     To make it easier to recognise underwater, the operating device for the underwater emergency exit should have black and yellow markings with at least two bands of each colour of approximately equal widths. Any other operating feature, e.g. highlighted ‘push here’ decal(s) for openable windows, should also incorporate black-and-yellow-striped markings.

[Amdt No: 27/5]