JammedStab
22nd May 2013, 02:57
ICAO Annex 14 prescribes the minimum distance
from the threshold of the aiming point marker. Surveys of actual markings on
runway indicate that in reality things may be quite different.There are many
examples of aiming point markers that are much further away from the threshold
than recommend by ICAO. This would mean that the aircraft could land much
longer than assumed. An example is an airport in Europe where the aiming point
was located at almost 500 m from the threshold whereas 300 m was advised by
ICAO (runway was 2,200 m long). Analyses of flight data of landings at this
particular runway showed a 14% longer airborne distance than the fleet average
and a twice as high probability of a long landing. There are many more similar
examples for other airports. Touchdown aiming point markers that are further
away than recommend can contribute to the occurrence of long landings.
There are pilots that believe that the aiming point marker is always located at the
same position for each runway. Clearly this is not the case. Also the fact that the
PAPI is not always located next to the aiming point is not considered by every
pilot. This could lead to longer landings for smaller aircraft than for which the
PAPI was setup
http://www.nlr-atsi.nl/downloads/landing-long-why-does-it-happen.pdf
from the threshold of the aiming point marker. Surveys of actual markings on
runway indicate that in reality things may be quite different.There are many
examples of aiming point markers that are much further away from the threshold
than recommend by ICAO. This would mean that the aircraft could land much
longer than assumed. An example is an airport in Europe where the aiming point
was located at almost 500 m from the threshold whereas 300 m was advised by
ICAO (runway was 2,200 m long). Analyses of flight data of landings at this
particular runway showed a 14% longer airborne distance than the fleet average
and a twice as high probability of a long landing. There are many more similar
examples for other airports. Touchdown aiming point markers that are further
away than recommend can contribute to the occurrence of long landings.
There are pilots that believe that the aiming point marker is always located at the
same position for each runway. Clearly this is not the case. Also the fact that the
PAPI is not always located next to the aiming point is not considered by every
pilot. This could lead to longer landings for smaller aircraft than for which the
PAPI was setup
http://www.nlr-atsi.nl/downloads/landing-long-why-does-it-happen.pdf