COLD WEATHER PROCEDURES

PREFACE TO COLD WX PROCEDURES

If freezing precipitation is present a visual inspection immediately prior to takeoff (within 5 minutes) is now required."
"There is no established holdover time for Mil Spec deicing fluid."
"During all phases of flight, if the aircraft enters clouds/visible moisture at temperatures less than 10 Celsius, turn on all anti-ice systems whether the ice detect system indicates icing conditions or not."(D/7-13)

COLD WEATHER PROCEDURES

(chronologically arranged)

  1. *Under no circumstances will flights be planned through forecast or known severe icing conditions to include freezing rain or freezing drizzle. (D/7-8)
  2. If ground heaters are not available, start the APU as soon as possible, and use the aircraft's heating system to preheat both the flight station and the cargo compartment. (D/7-10)
  3. Light frost (1/8" or less) is permissible on the fuselage, and frost on the underside of the wings caused by cold fuel is ok. No other frost or ice is permissable.
  4. Eng. start should be delayed until the takeoff can be accomplished within approx. 10 minutes. (D/7-11)
  5. If the OAT is 8C or below with visible atmospheric moisture present, the eng.anti-icing should be turned on after eng. start. When ambient temp. is above 10C, 50F, do not operate eng. anti-ice for more than 10 sec. (D/7-11)
  6. If the a/c surfaces are cleared of ice after preflight, check spoiler operation. (D/7-11) As a technique, do this when you check the flight controls as part of the BEFORE TAXI checklist; also, consider cycling the flaps.
  7. Taxi at reduced speed; avoid taxiing in deep snow or slush because taxiing will be more difficult and the brakes and gear may freeze after takeoff. (D/7-12)
  8. If visible moisture is present & the OAT is 8 C or below, the engs. should be operated at a high thrust setting for 10 sec. every 10 min. to prevent ice build-up on the eng. inlet components. If surface conditions preclude advancing engs. to at least 70% N2, do not takeoff. (D/7-12)
  9. The fuel heater switches should be placed "on" for one minute prior to takeoff whenever the fuel temp. is 0C or below, but should not be used during takeoff or go-around. On the ground, the fuel heaters may be used at idle thrust if the engines have been operating at idle for 5 min. or more. If not, the fuel flow should be increased to a min. of 1500 PPH before operating the fuel heaters. (D/1-10,7-12)
  10. If freezing precipitation is present, a final visual check of the aircraft/wing surfaces will be made just before take-off (within 5 minutes) by opening the #1 hatch and scanning the tip of the wings to determine if the surfaces are still free of ice. (D/7-13)
  11. Takeoffs will not be attempted w/ over 1/2" of wet snow, slush, and/or water, or 3" of dry snow on the runway. (D/7-12,10)
  12. Turn on the engine anti-ice during the lineup checklist if visible atmospheric moisture is present and the OAT is 8C or below or, if icing conditions are anticipated before climb power is set. (D/7-13)
  13. Prior to brake release, slowly advance the throttles toward 70% N2 for 10 seconds to shed ice from the engine inlet components. If skidding occurs before 70% N1, release brakes immediately and begin the takeoff. If ice remains visible at eng. inlet guide vanes, do not takeoff. (D/7-13)
  14. If performance permits, consider delaying gear retraction to prevent snow or slush freezing in the wheel wells. (D/7-13)
  15. Wing anti-ice should be turned on after takeoff in icing conditions. If TRT EPR was used for takeoff, adjust throttles to maintain .045 below takeoff EPR. If reduced EPR was used, adjust throttles to maintain takeoff EPR. (D/7-13)
  16. CAUTION: the CONTINUOUS IGNITION switch shall be "ON" for flight in known or anticipated icing conditions. Turn continuous ignition on before turning engine anti-ice on. The wing & engine anti-ice should be turned ON prior to entering icing conditions. Adjust EPR if NRT or MRT is being used. Empennage de-ice should be turned on after entering icing conditions. (D/7-9,13)
  17. During all phases of flight if the A/C enters clouds/visible moisture at temperatures < 10 C, turn on all anti-ice systems whether the ice detect system indicates icing or not. (D/7-13)
    If CADC failure occurs due to pitot system icing, turn the related stall prevention system off. If any heating element malfunctions in the pilot's or copilot's system, immediate action should be taken, where practical, to get out of icing conditions. (D/7-9)
    For accumulation of ice that exceeds 1/2", manually actuate the eng. anti-icing system one eng. at a time, and be alert for the eng. stall that will occur when the ice is ingested into the eng. (D/7-13)
  18. The rain removal system is very effective for removing ice from the windshield; if windshield heat is not adequate, use the rain removal system. (D/7-14)
  19. If moderate icing is expected during descent, turn on engine and wing anti-ice approximately 10,000' above the expected icing level. Adjust at least one throttle on each wing to 70% N2 RPM to maintain adequate bleed air for anti-icing. (D/7-14)
  20. The aircraft should not be landed with ice in excess of 1/2" on an outer wing section because lateral control of the a/c will deteriorate. If significant ice accumulations exist, a controllability check should be performed to establish the proper approach speed. (D/7-13)
Do not use reverse thrust below 50 knots because loose ice and snow will be blown forward, restricting vision. (D/7-13)

ICING EQUIPMENT TEST LIMITATIONS:

  • Engine anti-ice - 10 sec. above 10 C(50F)
  • Wing anti-ice - 30 sec. max (do NOT use on the ground)
  • Empennage de-ice - one test cycle in dry air flight
  • Rain removal - momentarily on a dry windshield
References: D/7-11, 1-43, 1-45, 1-40, respectively.

Minimum RCR is 3 . ( See chart, P/3-27)
RCR is for + 20 ft. from runway centerline.
Under NO Circumstances will the aircraft APU or engines be started until deicing operations are complete. (D/7-10)

LIMITATIONS

ENGINE:

Max. EGT at TRT,G/A, Reduced EPR - 555 C / 5 min.
MRT - 510 C / 30 min.
NRT - 485 C / continuous (D/5-22)
Starting - 455 C; approaching 400 C, => STOP START! (D/1-14)
idle - 340 C (as a guide, not a limit)
accel. - 555 C
reverse 555 C (D/5-22)
Do not exceed 30 sec. in reverse thrust at any power setting above REVERSE IDLE. Allow 15 min. cooling between applications. (D/3-92)
Whenever the EGT exceeds 565 C for any time, either shut down the engine or land as soon as possible. When shutting the engine down for this reason, allow a cooling period of 5 min. at IDLE RPM prior to shutdown if engine conditions and flight circumstances permit. (D/5-22)
N1 - Normal ..... 25% to 93% RPM Max ...... 101%
N2 - Normal ..... 54% to 99% RPM Max ...... 104%
(D/5-19)
Starter: 1.5 min ON, 5 min. OFF, for any number of duty cycles. The OFF time must be observed regardless of ON time. (D/5-4)

OXYGEN:

  • 290-430 psi (crew) (D/1-234)
  • 300 psi (troop) (D/1-236)
  • 100 liters - troop sys. for airevac. (A/15-4)
  • 5 liters - min. for stateside/locals. (D/2-27)

WING FLAP MOTOR:

  • Dual motors - one cycle/ 2 min.
  • Single motor - one cycle/5 min. (D/1-53)

WEIGHT LIMITATIONS:

  • Max. ramp weight 325,000# (D/5-2)
  • Taxiing limitations above 318,000# (D/5-4)
  • Max flight wt. 323,100# (D/5-2)
  • Max landing wt 323,100# (D/5-2)
  • Max push back/tow wt 325,000# (D/3-90)
  • Backing the aircraft 240,000# (D/3-92)
  • Max. fuel wt 153,352# (D/5-2)
  • Max. zero fuel wt 218,725# (D/5-2)
  • Normal landing wt 257,500# (D/5-2)
  • Normal landing fuel wt 75,000# (D/5-2)

AIRSPEEDS:

  • Gear operation 200 KCAS / .48M
  • Gear down 235 KCAS / .55M
  • Flaps Approach 200 KCAS / .48M
  • Flaps Landing 185 KCAS / .45M
  • Landing lights 350 KCAS / .53M
  • Stab access door 280 KCAS / .75M
  • Air refueling door 350 KCAS / .825M
  • Spoilers (ground) 147 KCAS
  • Spoilers (flight) 350 KCAS / .75M
  • Petal doors, ramp, & troop doors 200 KCAS/.48M (D/5-6)

WIND LIMITATIONS (A/5-3,9-4)

  • Max. winds 50 knots
  • Max. tailwind 10 knots
  • Max. crosswind 25 knots
  • Rudder pedal steering inop. 20 knots X-wind, max.
  • Spoilers inoperative. 20 knots X-wind, max.
  • Rudder depowered 10 knots X-wind, max.
  • Actual Cat II approach. 10 knots X-wind, max.
  • Cat II (training.). 15 knots X-wind, max.
  • No-flap (actual) 25 knots X-wind, max.
  • No-flap (practice) 15 knots X-wind, max.
  • If the runway is wet or icy, takeoff or landing shall not be made in the "caution zone" (of the crosswind landing chart). (P/3-19)