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Je me permets d'éclairer un peu vos lanternes.
Le système "Pulse Light" fait clignoter alternativement les landing lights (gauche et droit).
Exemple les Pulse Lights équipant le Gulfstream 550
OM-Part B (enfin celui de ma compagnie) précise leur utilisation :
A.
Pulse Light
Shall be turned ON :
1. When lining up on the active runway until reaching 10,000 ft AAL,
2. In descent when below 10,000 ft AAL,
3. Whenever maximum lighting is required
Pulse Light are not inhibited above 18,000 ft.
Pulsation is inhibited when Landing Lights are switched ON, until above 18,000 ft.
Shall be turned OFF :
After vacating the runway.
B.
Landing Lights (pour comparer)
Shall be turned ON when cleared for take off.
Shall be turned OFF after landing gear retraction.
Shall be turned ON when the landing clearance is received, until vacating the runway.
Landing lights are inhibited above 18,000 ft.
GULFSTREAM 550 OPERATING MANUAL
Landing and Pulse Lights:
The landing lights consist of one sealed-beam, fixed-aim landing light
located in the leading edge of each wing. The lamp is rated at 600,000
candle power, with a horizontal beam spread of 12° and a vertical beam
spread of 8°. Each landing light has a dedicated cockpit control indicator /
switch. These switches are also located in the EXTERIOR LTS section of
the overhead, and are labeled L LDG and R LDG.
An additional switch allows the flight crew to alternately flash the left and
right landing lights. This function is controlled by a switch labelled PULSE
in the EXTERIOR LTS section of the overhead. The flight crew can
override the pulse function by pressing the L and R LDG switches,
returning the lights to normal simultaneous operation. (The alternately
flashing landing lights can produce strong vertigo sensations if operated in
low visibility.)
The lens covering the landing lights is de-iced whenever wing anti-ice is
operating. Warm engine bleed air is routed through perforated tubes within
the lens housing to clear away any ice accumulation and preserve the
illumination intensity of the landing lights.
NOTE:
The landing lights automatically extinguish when the aircraft reaches an altitude of 18,000 feet, if the flight crew has not manually selected the L LDG and R LDG switches OFF. This prevents bulb failure caused by
thermal shock at high altitudes. On descent through 18,000 feet, the landing lights automatically illuminate if the flight crew has left the switches in the ON position. The altitude switching is controlled by the
Landing Light Control Unit.
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