FL180

G´day,

could anybody tell me please what "screen height" means in general?

Many thanks

Andy

john_tullamarine

Generally, the defined

(a) end of the declared takeoff distance - point at which the calculated aircraft flight path has climbed to a nominated height - 35ft (heavy aircraft), 50ft (light aircraft). Gets a bit complicated for heavy aircraft in the detail but, if you have an ATPL as your profile indicates, you have had the usual theory training in the various takeoff distance considerations ...

(b) commencement of the declared landing distance - point at which the calculated aircraft flight path passes 50ft height

jtr

Not disagreeing with the abv, but to expand...

(Laymans terms)

the 35' (or 15' if RWY is wet) assumes a/c suffers engine failure at V1

john_tullamarine

Not so ...

(a) for a light aircraft, engine failure is not considered

(b) for a heavy aircraft, the all engines distance is one of the takeoff cases to be considered and, likewise, finishes at the factored distance where screen is achieved.

jtr

Was only thinking of heavies.

See what you mean though in regard to the all engine perspective.

I was thinking backwards from the perspective of TODR/TORR, where it must be the longest of...


All eng to V1 - 1 sec, Eng Fail, Continue, reach 35' @V2

or

All eng to V1 - 1 sec, Eng Fail, Abort, Stop

or

All eng to 35' above runway X 1.15

I imagine there are a/c around (do you have an example?) where the most limiting is the 1.15X all engine dist to screen ht (Civil b-52?)

Bow to your wisdom.

john_tullamarine

Will depend on the individual Type .. however, all engine distance with the factor will tend to be limiting when the OEI performance is comparatively good .. ie low Hp, low OAT, low GW, high V1/VR.

Keep in mind that the limiting case will likely vary throughout the operational envelope.