Re: Overhead obstructions in modern airliners

Date:         17 Sep 97 02:49:26 
From:         Chris Hall <>
Organization: Airborne Display Limited
References:   1
View raw article
  or MIME structure

>Although Bob's reference was in relation to airliner windows, his
>mention of the 50th percentile basis for ergonomic determination raises
>the question of overhead obstructions in some modern airliners,
>specifically those television monitors which are angled down several
>inches (many centimetres) below the nominal over-aisle roof line.
>I am 185 cm (6'2") tall and have occasionally bumped my head on the
>lower edge of one of these monitors during normal de-planing. I have
>also noticed tall cabin attendants having to "duck" the monitors during
>their normal in-flight duties.
>I have always been concerned that during an evacuation (when the cabin
>may be dark and/or smoke filled) the monitors may present a safety
>hazard to passengers and - most particularly - tall cabin crew members.
>And does anyone have indication of the crash-worthiness of the monitors;
>are they likely to remain intact and in situ following a heavy landing ?

Cass, the monitors are guaranteed to stay secure in a 12g acceleration.
Over 12g, they may break loose, but over 12g the passengers would not
care anyway!

I have been involved in the design of an overhead monitor installation,
and there are no specific rules in the UK about clearances apart from
common sense. During a meeting discussing clearances, a comment was made
that tall people are more aware of the risk of bumping their head, so
take more notice of clearances. Good point.

In a lot of Boeing 757 installations, the front monitor is manually
retractable in order to improve head clearance when passengers are

Chris Hall