We thank Mr Chui Tau Siong for his letter (Empty seats by emergency doors a flight risk; March 7).

He expressed concern about seats by the emergency exits on a budget airline flight being left unoccupied.

We wish to clarify that there is no safety concern arising from these seats not being occupied and these "self-help" emergency exits not being manned.

Under international rules, they are not required to be manned, as they are merely supplementary to the mandatory emergency doors with which all commercial aircraft are equipped and which cabin crew are required to man and operate themselves during an emergency.

If a passenger is available to help open the self-help exits, it can be useful, but if not, the mandatory emergency doors are designed to be sufficient on their own.

Airlines sometimes charge a fee for seats at "self-help" exits, as they offer more leg room.

This, however, is a commercial decision by the airline and is independent of and does not affect safety considerations.

We thank Mr Chui for writing on this matter.

Should he require further clarification, he may contact us at: caas_afo_infocenter@caas.gov.sg

Ong Keng Peng (Captain)

Head (Flight Operations)
Airworthiness and Flight Operations Division
Civil Aviation Authority of Singapore