Aircraft Landing Performance Flashcards
WAT Limit
The highest temperature for which an approach, landing and missed approach climb requirements are satisfied at Maximum Certified Landing Weight. For higher temperatures performance cannot be achieved at Max Landing weight - for these sometimes a correction factor will be published or alternatively a new, lower, limit weight can be calculated using QRH Go-around climb gradient and landing climb limit tables.
WAT limits are calculated at 2000ft above airfield elevation. To calculate equivalent levels of performance using the QRH tables you will have to enter at 2000ft above aerodrome level.
Slippery Runways
Max Tailwind for landing - 5kts
Flooded runways must be considered as slippery.
Runway may be promolgated ‘SLIPPERY WHEN WET’
Reverse Thrust
SOP to always use at least IDLE reverse thrust on landing.
FULL Reverse thrust MUST be used when-
1) The runway is contaminated.
2) The target threshold speed has been increased for a deficiency.
3) There is any unserviceability of speed brakes, wheel brakes or anti-skid.
Wet Runway
Defined as a runway whose surface is covered by any visible dampness or water up to and INCLUDING 3mm deep within the area intended to be used and has a friction coefficient of 1 half that of a dry runway but with ‘braking action good.’
Landing Field Length Limit Adjustment for DDG Corrections.
Only applicable to DDG entries where a correction is required to the Landing Field Length Limit NOT for Landing Climb Limit Adjustments (see Landing Climb Limit Data in QRH for these)
Where a DDG item requires a decrement to the performance limited field length landing weight - if a tailwind component is shown in association with the MLW this can be used to calculate a increased conservative performance limited weight by adding 2000 kg per knot to the tailwind indicated.
Eg. 208.6 (15) then 15 x 2000 kg can be added to give a perf limited weight of 238,600 kg.
The performance decrement specified in the DDG can then be subtracted from the higher perf limited weight.
Contaminated Runway Definition
A runway is considered contaminated when a significant portion of the runway surface area (whether in isolated areas or not) within the required length and width being used is covered by one or more of the following: MORE THAN 3 mm of water/wet snow/ dry snow / slush, compacted snow or ice.
Note: for depths of 3 mm or less the runway is NOT considered to be contaminated and WET runway data should be used.
Note: performance data for contaminated runways assumes a uniform depth of contaminant along the entire length and width of the runway which is an unlikely situation.
Landing on Contaminated or Degraded Braking Action Runways.
Landing data is provided in 2 different manuals-
1) Performance Manual (Planning / Dispatch data)
Data meets and is factored according to certification requirements.
AND
2) QRH / FCOM (Advisory data)
The landing data in the QRH is actual demonstrated data for various configurations and conditions. Normal configuration data is already factored by 15% as required by the regulation. Non-normal configuration data is UNFACTORED and a 15% margin must be manually applied.
Landing in Snow and Slush
Landing is permitted in up to 10cm (4in) of dry snow.
Wet snow should be treated as slush and compacted snow as ice.
Minimum acceptable CLEARED width of runway is 40 metres (130 ft).
See perf manual for snow bank limitations.
Landing in slush or excessive water deeper than 13mm (0.5 inches) or snow deeper than 10 cms should be avoided where possible as airframe damage could occur.
Dispatch Landing Weight Calculation
Regulatory requirement to complete.
When a runway is contaminated, autoland required, or if a defect which impacts landing perf arises after final OFP release, dispatch landing weight calculation must be completed.
