Cold Wether Ops Flashcards
What do you do if while cruising the fuel temp approaches the lowest admissible value?
Descending couple thousand feet will normally help
On an ILS approach and a very cold day -20C, a plane received an EGPWS terrain warning.
Why and how to comply with?
On cold day the altimeter might read higher altitudes then actual one.
The calculated minimum safe altitude must be adjusted
1C x 18ft
If the alt is warmer than -15C
A 4% hight correction
For colder temps Tables A [meters] and B [feet]
ATC radar vectors shall NOT be adjusted
When altitudes corrections are applied to a published approach procedure , pilots are required to advise ATC of the corrections - not inside FAF
A runway is considered contaminated when?
25% or more of the runway is covered with isolated or not
1 Surface water exceeding 3 mm or 0.125 inch , slush, loose snow
2 Compacted snow
3 Ice including wet ice
Landing distance should be calculated
Without TR and recommended to add a 15% margin
Regarding crosswind on wet, snow packed or icy runways……
A 50% reduction should be considered on the compacted snow or ice
A 75% when runway us icy or breaking action is poor
How would one plan to calculate landing distance on contaminated runways?
Plan and execute flights for the worst surface condition possible
Ask for updates from all parties: ATC, ops, dispatch, and airport operator
Braking coefficients
Good - More capability is available, however, the landing distance will be longer than the certified ones
Medium - Noticeably degraded braking action conditions.
Poor - Very degraded braking conditions with a potential for hydro planing
Nil - No braking action and poor directional control
ICAO contaminated runways
DRY - Dry , no reports
GOOD - Wet or dry snow less than 20 mm
MEDIUM - Packed or Compacted Snow
POOR - Wet Snow, Slush, Standing Water or Ice
NIL - Wet Ice
MU Scale
MU values ranges from 0 to 100 where the 100 is the higher friction
Only MU values below 40 are normally reported by ATC and is where the braking action begins to deteriorate and under 20 is NIL
FZRA
Frizzing rain
Requires a temperature inversion
When a warmer air mass overlies a colder one.
Factors that affects the rate of ice accumulation
TEMPERATURE
Static Air Temp +2C & -20C
Droplets Size - The larger droplet the further aft the ice will accumulate.
MOISTURE -
Best COLD WX operating practices
Clean Aircraft Concept
PreTakeOff contamination check
No flight into known or forecast severe icing conditions
