Aerodrome 2, 3, 4, 5, 6 and 7 Flashcards
When should appropriate aerodrome lighting be displayed?
By day: High intensity systems, where installed on the runway to be used, whenever the visibility is less than 5km and/or the cloud base is less than 700ft
By night: At all times irrespective of weather conditions
When the reported visibility consists of two values, the lower of the two values shall be used
In which document are the rules governing lights and pyrotechnic signals used to control aircraft and vehicles at aerodromes?
SERA 923/2012
Define Windshear
Windshear is a sustained change in the wind velocity along the aircraft flight path, which occurs significantly faster than the aircraft can accelerate or decelerate.
Where is Windshear most dangerous?
Windshear can occur at any level, but low-level windshear (below 1,500ft) is the most dangerous, as it can cause problems of sufficient magnitude to affect the control of aircraft in departure or final approach phases of flight.
What conditions are conducive to Windshear?
ATCOs should be alert to the possibility of windshear in the following circumstances:
a) The presence of frontal/squall/thunderstorm activity in the vicinity of the aerodrome
b) The presence of low-level inversions where the surface wind will be significantly different from that at only a few hundred feet above the ground
c) Local terrain or buildings when considered in relation to wind speed and direction. Large obstructions can cause windshear as well as the more usual turbulence and gusts.
What may happen if a windshear alert is generated whilst an aircraft is in a turn?
The crew may level the wings to maximize the climb gradient, unless a turn is required for obstacle clearance.
What may the pilots reply to an ATC instruction during a windshear event?
Due to high flight deck workload the reply ‘Standby’ in response to ATC instructions is usual during windshear events.
What are the times of Windshear alerts generated on aircraft?
Predictive
Reactive
Which takes precedence over Windshear or TCAS alerts?
Windshear alerts take precedence over TCAS, as the priority of the crew during windshear recovery manoeuvres is to keep the aircraft under control whilst ensuring terrain clearance.
A windshear escape manoeuvre usually means a high rate of climb. What may happen as a result?
The high rate of climb can result in pilots exceeding their cleared level and eroding separation from other aircraft.
What should ATCOs be prepared for if a pilot executes a missed approach due to windshear?
ATCOs should be prepared for the aircraft to exceed the missed approach altitude. ATCOs should provide enhanced traffic information and instructions as necessary to ensure safety.
What should ATCOs do upon receipt of a pilot report of windshear?
The information shall be relayed to subsequent inbound and outbound aircraft until confirmation is received that the condition no longer exists.
At aerodromes where ATIS is available windshear information may be included in the broadcasts. ATCOs should amplify the information for individual aircraft if necessary.
What should windshear reports from pilots contain?
1) A warning of the presence of windshear
2) The height or height band where the shear was encountered
3) The time at which it was encountered
4) Details of the effect of the windshear on the aircraft, e.g. speed gain or loss, vertical speed tendency, change in drift.
Define Prevailing Visibility
Prevailing visibility is defined as the visibility value that is reached or exceeded within at least half the horizon circle or within at least half of the surface of the aerodrome. These areas could comprise contiguous or non-contiguous sectors.
When is minimum visibility reported?
Where the visibility in any direction is less than 50% of the prevailing visibility or less than 1500 metres, the lowest visibility observed and the general direction will also be reported. If it occurs in more than one direction, the most operationally significant direction will be reported.
