Adverse Wx Flashcards
Engine Anti-ice Operation - On the Ground
When engine anti-ice is required and the OAT is 3°C or below, do an engine run up, as needed, to minimize ice build-up.
Use the following procedure:
Run-up to a minimum of 50% N1 for approximately 1 second duration at intervals no greater than 60 minutes.
Engine Core Ice Shedding for Trent 800 engines
Do the procedure when freezing fog with visibility 300 meters or less If takeoff cannot be achieved within 45 minutes total taxi time:
If OAT is 0 degrees C to -6 degrees C, run-up the engines to 50% N1 for 60 seconds every 45 minutes.
If OAT is -7 degrees C to -13 degrees C, run-up the engines to 59% N1 for 60 seconds every 45 minutes.
Fan Ice Removal
During flight in moderate to severe icing conditions for prolonged periods, if fan icing is suspected due to high engine vibration, the fan blades must be cleared of any ice
Do the following procedure on both engines, one engine at a time: quickly reduce thrust to idle for 5 seconds
then restore the required thrust.
If vibration persists, advance thrust lever to 90% N1 momentarily.
Using flaps After prolonged operation in icing conditions with the flaps extended, or when an accumulation of airframe ice is observed, or when operating on a runway or taxiway contaminated with ice, snow, slush or standing water:
Do not retract the flaps until the flap areas have been checked to be free of contaminants.
Moderate to Heavy Rain, Hail or Sleet
Flight should be conducted to avoid thunderstorms, hail activity or visible moisture over storm cells.
To the maximum extent possible, moderate to heavy rain, hail or sleet should be avoided.
Severe icing conditions
CAUTION:
Avoid prolonged operation in moderate to severe icing conditions.
Severe Turbulence structural consideration:
Flap extension in an area of known turbulence should be delayed as long as possible because the airplane can withstand higher gust loads in the clean configuration.
Diversion to another airfield is recommended if severe turbulence persists in the area.
Flight in Turbulence
During climb and descent, use of VNAV or flight level change may result in excessive pitch changes as the AFDS attempts to fly speed with the elevators.
Therefore, vertical speed mode (speed on autothrottles) is recommended for climb and descent in severe turbulence.
During cruise, VNAV and altitude hold modes both fly speed on autothrottles and can be used in turbulence.
Use of Thrust in Severe Turbulence
In severe turbulence during cruise, it may be necessary to disconnect the autothrottles to prevent excessive thrust changes.
Thrust setting guidance is available on EICAS when VNAV is engaged.
Set EPR at or slightly above the magenta VNAV target EPR indication.
Change thrust setting only if required to modify an unacceptable speed trend.
Windshear Precautions Take Off
Takeoff
• Takeoff with full rated takeoff thrust is recommended, unless the use of a fixed derate is required to meet a dispatch performance requirement.
• For optimum takeoff performance, use flaps 20 for takeoff unless limited by obstacle clearance and/or climb gradient.
Flaps 15 may be used as a precautionary setting and will provide nearly equivalent performance to Flaps 20.
• Should airspeed fall below the trim airspeed, unusual control column forces may be required to maintain the desired pitch attitude.
If stick shaker is encountered, reduce pitch attitude.
Do not exceed the Pitch limit Indication.
Windshear precautions Approach and Landing
• Use either Flaps 25 or 30 for landing.
