OPERACIÓN EN TIEMPO FRÍO B732 RECOMENDACIONES GENERALES APLICABLE A TODA LA FLOTA B732	fernandoliberman@fibertel.com.ar   ULTIMA ACTUALIZACIÓN 25/11/2006 13:38

ESTAS SON PAUTAS GENERALES QUE DE NINGUNA MANERA SUSTITUYEN LOS PROCEDIMIENTOS CONTENIDOS EN EL FCOM, MANUAL DE DESPACHO Y EL MANUAL DE OPERACIÓN EN TIEMPO FRÍO PARA TODA LA FLOTA DE LA COMPAÑÍA. SOLO PRETENDEN RESALTAR AQUELLOS ASPECTOS DE LA OPERACIÓN PARA LOS QUE SE RECOMIENDA UN ESPECIAL CUIDADO.

B737-200 ADV

COLD WEATHER OPERATIONS/ ICING CONDITIONS OPERATIONAL TIPS

AUTOR: Esteban Zapperi (Austral Líneas Aéreas)

Exterior Safety Inspection

• Takeoff with light coating of frost, up to 3 mm on lower wing surfaces due to cold fuel, is permissible. All leading edge devices, control surfaces, upper wing surfaces and cavities must be free of snow or ice. SP.16.1
• Thin hoarfrost is aceptable on the upper surface of fuselaje provided all vents and ports are clear. SP.16.1

Operation with Deicing/Anti-icing fluids

• Although no performance adjustments are required, it is recommended that a 5 ºC buffer on the maximum assumed temperature be used when performing reduce thrust takeoffs (assumed temperature method). SP.16.3
• Ensure that the recommended takeoff rotation is observed and use a takeoff flap 10 or greater whenever possible. SP.16.3
• Avoid rapid rotation. FCT 2.28

Ice & Rain Protection

• Engine anti-ice must be on during all ground and flight ops when icing condition exists or are anticipated. SP.16.3
• In icing conditions inflight, maintain a minimum of 40% N1(TAT between 0 and 10ºC) or 55% N1 (TAT below 0ºC); in moderate to severe icing conditions with TAT below -6.5ºC maintain 70% N1 RPM or higher. L.10.5/SP.16.3
• With ground operational wing anti-ice, the wing anti-ice system must be on during all  ground ops between engine start and take off , unless the airplane  is protected with Type II or IV fluid.

Ground use of the wing anti-ice is intended to complement,  not to replace ground deicing/anti-icing and inspection procedures. SP.16.4

Preliminary Flight Deck Preparation

·        Battery installed and fully charged. SP.16.5

·        The APU should be pre-heated to above –40 ºC to ensure proper operation. SP.16.5

·        Flight  controls check. SP.16.5

·        Pitot heat ON. SP.16.5

Engine Start

·        The start valve may be frozen, ground heating  and Manual Start may be necessary. SP.16.6

·        If OAT is below –35ºC, idle the engine for 2 minutes. SP.16.6

·        Idle thrust until oil press returns to normal range. Filter Bypass light should extinguish. SP.16.6

After Engine Start

·        During cold weather start, a temporary high oil press above limits may be tolerated. SP.16.6

·        No oil press in 30’’ requires shutdown. SP.16.6

·        When starting a cold soaked engine, up to 3,5’ may be allowed for minimum oil press. SP.16.6

·        Following a precautionary shutdown, allow 10 to 15 minutes for internal heat to warm oil system. SP.16.6

·        If icing cond. are present, engine anti-ice must be turned on after engine start. SP.16.7

·        With moderate to severe icing conditions, periodic engine run-up at 80% N1 should be made at 10’ intervals for 15’’ duration. SP.16.7

·        The generators may need up to 5’ to produce steady power. SP.16.7

·        Check flaps and flight controls for full travel. Flap position ind. and LE devices ind. should be closely observed. If the flaps should stop, the flap lever should be placed in the same position as indicated. SP.16.7

Exterior Deicing with Engines Operating

·        Idle thrust. SP.16.7

·        Set the Stablizer trim in the  manual APL NOSE DOWN to prevent fluid and slush from entering in the stab. cavity. SP.16.7

·        Bleeds off. SP.16.8

·        If not required , turn the APU off  to avoid fumes and odors to enter the plane. SP.16.8

Taxi-Out and Takeoff

Taxi-Out

·        Use the steering to circulate warm hydraulic fluid. SP.16.8

·        Differential braking may be more effective than nose wheel steering on very slick surfaces, reduce speed prior to initiating a turn. FCT 2.5

·        Do not use reverse thrust on snow, ice, or slush covered surfaces. SP.16.8

·        If the flaps are left up during taxi to avoid slush and ice, the before takeoff  procedure will be completed AFTER the flaps are in the takeoff configuration. SP.16.9

·        On ice covered taxiways or runways, high crosswinds may start a skid. SP.16.9

Before Takeoff

·        When tank fuel temperature is 0ºC or below,  fuel heat to on for one cycle just prior to takeoff. Fuel heat must be off for takeoff. SP.16.9

·        With moderate to severe icing conditions, takeoff roll must be preceded by a static run-up to 80% N1. SP.16.9

Takeoff

·        EPR/N1 Cross Check. SP.16.10

·        V1 Minimum. SP.16.10

·        Takeoffs on slippery runways are not recommended if the crosswind exceeds 15 kt. or when slush or wet snow is more than 13 mm in depth. SP.16.10

·        The Boeing recommended maximum runway contaminant depth is 13 mm. FCT 2.28/PI.15.2/PI.15.5

·        The use of assumed temperature for reduced thrust is not allowed in contaminated runways. PI.15.2

·        Following deicing of the airplane, a visual inspection of the airplane wings should be made by the pilots just prior to takeoff. SP.16.10

·        Ice formations on empennage during takeoff or climb should be shed by accelerating the plane at low altitude to increase TAT. (8ºC rise by a 100 kt increase). SP.16.11

Climb

·        After the flaps are up, wing anti-ice should be turned on to melt any accumulation of slush.  SP.16.11

Cruise

·        Monitor fuel tank temperature. Fuel freeze point +3º C or –45º C, whichever is higher. SP.16.11/ L.10.10

·        The rate of cooling of the fuel is approximately 3º C per hour, with a maximum of 12º C. FCT 3.6

Descent & Approach

·        If ice are observed on airplane surfaces add 10 kt to the final approach speed. SP.16.12

Taxi-In and Park

·        With moderate to severe icing are present during prolonged ground ops, periodic engine run-up must be performed. This run-up should be made at 80% N1 at 10’ intervals for 15’’ duration. SP.16.12

·        After landing position the stabilizer between 0 and 2 units airplane nose down to prevent melting snow and rain from running into balance bay areas. SP.16.12

Securing for Overnight or Extended Periods

·        Below –18º C the Battery must be removed to keep starting capability of the APU. SP.16.13

Landing on Wet or Slippery Runways

·        After landing and/or if taxiing through water or slush, do not retract flaps beyond 15. SP.16.19

·        Do not use reverse thrust while taxiing. SP.16.19

·        Consider a GA  if zero drift conditions cannot be establish prior  to flare. SP.16.20

·        Auto Brake MED. SP.16.20

Engine Operation in Heavy Rain and/or Hail

·        Start descent early , maintain at least 55 % N1 . SP.16.21

·        The engine may not respond normally to thrust lever movement. SP.16.22

Engine Operation during Moderate to Severe Icing Conditions

·        A minimum N1 RPM of 70 % must be maintained . Necessary reductions should be limited to a maximum of one minute and never below 55 %. A minimum of 70 % N1 must be maintained following re-application of thrust, for at least one minute, before reducing thrust again. SP.16.23

EZ