Wet Contaminated Runway Ops Review (Notes from Pg # 201 & 346 DA-10 IPTM)
With the Fall season now here....Remember! ......
When operating on runways contaminated by standing water, in
addition to the aerodynamic drag, the aircraft is also subject to hydrodynamic
drag and plume drag. The total drag
increases proportionally up to Vh (hydroplaning speed) and reaches about 3,100
lbs for a 3/8 " water depth, then decreases slowly at speeds above Vh.
If the runway is contaminated by slush, wet snow, or dry
snow, the equivalent water depth should be determined before estimating the Vh. a chart for determining equivalent water
depth is found in the Falcon 10 Performance Manual.
When braking on non-dry runways, the braking coefficient of
friction may be reduced:
-by 20% to 50% on wet runways,
-by up to 75% on contaminated
runways,
-by 60% to 90% on snow-compacted
runways, and
-by 90% on very
slippery runways (icy)
The Following Recommendations are Summarized (See IPTM):
·
Wet
Runways >>>increase
landing distance by 15% and landing field length by 67%
·
Contaminated
Runways>>>>Operation on contaminated runways should be
avoided whenever possible, especially during and immediately after heavy
rainfall. If slush or snow, use the
Performance Manual charts to determine the equivalent water depth. Max
recommended water depth is .5 inches with operable anti-skid system and max
x-wind of 15 kts. Multiply the normal landing distance by 2.3 for landing field
length.
·
Snow-Compacted
Runways >>>>Not Recommended, however...Max crosswind is
limited to 5 knots / Landing distance is equal to the dry runway landing
distance x2 (compacted snow) to x3.4 (black ice). To this result, add 15% for the new landing
field length.
·
Very
slippery runways (icy)>>>>Avoid/Forget it! (summarized)
DA-10 Ice & Rain Protection Info:
I
The following cautions are found in the various Falcon 10 Operating Manuals and other available material and are for the guidance of pilots conducting winter operations:
Ice and Rain Protection:
Engine Anti-Ice (Ground or Flight)
· Engine Anti-Ice must be ON when total air temperature is below +5 Celsius and icing conditions are anticipated
· Engine anti-ice must be OFF when total air temperature is above +10 Celsius
|
FA-10 IPTM
Pg. 2-23
|
N1 Settings:
· For adequate performance of wing and engine anti-icing systems, the N1 speed of the operative engines must not be lower than the minimum values shown in the chart below:
|
FA-10 IPTM
Pg. 2-23
|
Notes: CAUTION: If ice has already started to accumulate, turn on the ignition system (start selector switches to AIRSTART) prior to selecting the engine anti-icing systems on; turn on the engine anti-ice systems one after the other with a time delay of no less than 30 seconds. Wing anti-icing can then be switched on.
|
% N1
| ||||
Phase of Flight
|
At -30 Celsius OAT
|
At -20 Celsius OAT
|
At -10 Celsius OAT
|
At -5 Celsius OAT
|
In-Flight
Min Recommended
|
76
78
|
73
75
|
67
69
|
62
64
|
Approach
|
69
|
69
|
69
|
64
|
One-Engine
|
88
|
85
|
79
|
74
|
*Engine settings for Anti-Ice
Windshield Electrical Heating:
· The PILOT & COPILOT Windshield control switches must not be selected to the MAX position except in flight and then only if the NORM Position is not sufficient in icing conditions.
|
WING ANTI-ICE (FLIGHT ONLY):
· Must be on in flight when total temperature is below +5 Celsius and when icing conditions are anticipated.
· Wing Anti-ice must be off when total temperature is above +10 Celsius
· Do not operate on the ground.
|
Caution: If red lights of main landing gear remain ON when retracting during icing conditions, ice may hinder the uplatching of main landing gear. Attempt gear retraction 3 times to clear ice; if unsuccessful, speed must not exceed VLO (190 kts) and fuel consumption can be increased by 33% at maximum.
|
