CH-47F: Limits Flashcards
Engine Oil Pressure
- Minimum pressure for NG at ground idle: 5 psi
- Minimum pressure for NG between 80-95%: 35 psi
- Minimum pressure for NG equal to or greater than 95%: 50 psi
- Normal operation: 35 - 90 psi
- Maximum for contingency power: 110 psi
- Maximum for cold weather starts: 150 psi
Engine Oil Temperature
- Maximum: 149°C
Engine Transmission Oil Temperature
- Maximum: 140°C
- ENG1 or ENG2 XMSN warning: > 190°C
Transmission Oil Temperature
- Maximum: 140°C
Transmission Oil Pressure
- Minimum at ground idle: 7 psi
- Minimum at 100% NR: 20 psi
- Normal operation: 20 - 90 psi
Utility System Hydraulic Pressure
- Low limit: 2500 psi
- Normal: 2500 - 3500 psi
- High limit: 3500 psi
Flight Control Hydraulic Pressure
- Low limit: 2500 psi
- Normal: 2500 - 3200 psi
- High limit: 3200 psi
Hydraulic System Temperature
- Yellow: 95° - 120°C
- Red: 120°C maximum
Rotor (NR)
- Minimum transient power-on: 91%
- Transient: 91 - 97%
- Normal: 97 - 101%
- Transient: 101 - 106%
- Maximum transient power-on: 106%
- Maximum during autorotation: 108%
- Maximum transient: 111%
Rotor Overspeed
- Should 108% NR power-off be inadvertently exceeded, no entry need be made on DA Form 2408-13-1 unless the rotor system accelerates and exceeds 111.5% NR. Even though no action is required when NR exceeds 108% power-off, but remains at or below 111.5%, willful operation shall not be conducted in this range.
NR Limit with Inoperative Cruise Guide Indicator (CGI)
- Flight equal to or less than 98% NR with an inoperative CGI is prohibited.
Starting and Shutdown
- The APU shall not be started with a tailwind in excess of 25 knots.
- Main engines shall not be started with a tailwind in excess of 10 knots.
Engine Temperature (PTIT)
- Maximum continuous: 816°C
- Maximum 30 minute operation: 854°C
- Maximum 10 minute operation: 899°C
- Maximum 2.5 minute operation: 932°C
- Max transient -12 seconds (never exceed): 943°C
Contingency Power
- Only to be used during actual emergencies
- Usage of contingency power up to 932°C is permissible for an unlimited number of occurrences, as long as each occurrence is 2 minutes 30 seconds or less.
- Transient power 932°C - 943°C is not to be greater than 12 seconds.
Gas Generator (NG)
- Ground idle maximum: 50%
- Maximum: 111%
Power Turbine (NP)
- Maximum: 111.5%
Engine Overspeed
- An NG overspeed exists when a speed of 111% NG is exceeded.
- An overspeed can cause over-temperature and/or over-torque.
Engine Torque (TQ)
- Maximum dual engine: 100%
- Maximum single engine: 123%
Fuel Limitations
- Only those fuels listed in Chapter 2 shall be used.
- Emergency fuel shall not be used for more than 6 hours cumulative time.
Maximum Gross Weight
- The maximum allowable gross weight is 50,000 pounds.
Cargo Hooks
- Structural limit of forward and aft hook: 17,000 pounds each
- Maximum tandem load (forward and aft hook): 25,000 pounds
- Structural limit of center hook: 26,000 pounds
- When a combination of internal and external loads are carried during the same flight and the external load exceeds 12,000 pounds, position internal load forward of the utility hatch.
Winch / Rescue Hoist
- Resuce hoist limit: 600 pounds
- Winch limit, straight line: 3,000 pounds
- Winch limit, one pulley: 6,000 pounds
- Winch limit, two pulleys: 9,000 pounds
- Winch limit, three pulleys: 12,000 pounds
- Winch maximum: 12,000 pounds
Cruise Guide Indicator (CGI)
WARNING
Sustained operation in the red or yellow band on the CGI will cause damage to the rotor dynamic components (i.e. pitch housing, swashplate assembly, etc.) resulting in failure of parts, destruction of aircraft, and injury or death to the crew.
- Any excursion into the red or yellow band for more than 45 seconds requires an entry on the DA Form 2408-13-1.
External Cargo Airspeed
- If a sling or hook should fail while carrying a tandem load, limit airspeed to a maximum of 60 KCAS.
Airspeed Limits: Rearward Flight / Tailwind for a Hover
CAUTION
A dual FADEC primary channel failure may occur when rearward flight or a tailwind exceeds 40 KCAS. These conditions should be avoided.
- Maximum airspeed in rearward flight: 45 knots
- Maximum tailwind for hover: 45 knots
Airspeed Limits: Cabin Door / Rescue Hatch / Left Side Escape Hatch
- Maximum airspeed with lower section of cabin door open: 60 KCAS
- Maximum airspeed to open/close upper cabin door: 100 KCAS
- Maximum airspeed to open/close rescue hatch: 90 KCAS
- Left side escape hatch: do not install/remove in forward flight
Airspeed Limits: Windshield Wipers
- Maximum airspeed for windshield wipers on: 130 KCAS
LCT Airspeed Limit
- Do not manually extend the LCT beyond the GND position below 60 KCAS.
DAFCS Airspeed Limits
- Airpseed limit for single DAFCS: 100 KCAS or Vne, whichever is slower
- The helicopter may be operated with both AFCS off up to 160 KCAS or Vne, whichever is slower, provided both DAFCS are disabled below 100 KCAS.
Aerobatics Prohibition
- Aerobatics are prohibited with this helicopter.
- Aerobatics are defined as intentional maneuvers beyond plus/minus 30° pitch and/or 60° roll.
Bank Limitations
- With an operative CGI, bank angles are limited by the CGI, but no greater than 60°.
- With BALT/RALT engaged, limit bank angles to a max of 45°.
- With an inoperative CGI, use bank angle chart (Figure 5-11).
Landing Limitations: Ground Speed for Roll-Ons
- 60 knots ground speed
Landing Limitations: Nose-Up Attitude During Landings
- 20°
Landing Limitations: Rate of Descent
- R/D at touchdown for GW up to 33,000 pounds: 492 fpm
- R/D at touchdown for GW 33,000 - 40,000 pounds: 450 fpm
- R/D at touchdown for GW > 40,000 pounds: 360 fpm
Ground Operation Limitations
Thrust in ground detent:
- Right or left direction pedal: 0.75 in
- Aft cyclic: 2.00 in
- Lateral cyclic: 1.00 in
- TCL: no lower than ground detent
Thrust out of ground detent:
- Droop stop pounding
Ground Operation: Taxiing
- Wheng ground taxiing less than 75 feet from an obstruction on an unimproved/unfamiliar airfield not designated for CH-47F helicopters, a blade watcher and taxi director shall be positioned.
Flight Under IMC Conditions
NOTE
Should one DAFCS fail during IMC flight, the flight may be continued to destination. Should both DAFCS fail during IMC flight, exit IMC as soon as practicable.
The helicopter is qualified for IMC flight provided the following:
- Both DAFCS are operational
- Both SFDs are operating
- 3 MFDs (1, 4, and either 2 or 3), 2 CDUs, 2 GPPUs, 2 DCUs, 2 EGIs and 2 ADCs are operational
- Coupled ILS approaches at localizer intercept angles > 60° are prohibited.
Shock Absorber Vent Valve
- Must be open for operation below: -18°C
- Must be closed for operation above: -1°C
- May be opened or closed: -18°C to -1°C
Flight in Ice
- Continuous flight in light icing conditions below +5°C is not recommended since blade damage can occur from asymmetrical ice shedding.
Thunderstorm Operations
- If any lightning calbes or straps are missing or broken, avoid flight in or near thunderstorms, especially in areas of observed or anticipated lightning discharges.
Operations with Skis: Max Airspeed
- 130 KCAS or Vne, whichever is slower
Operation with Skis: Taxi Speed
- Maximum taxi speed is 5 knots ground speed when operating on hard prepared surfaces.
Operation with Skis: Rate of Descent
- Max R/D at touchdown in snow GW up to 33,000 pounds: 480 fpm
- R/D decreases linearly from GW of 33,000 to 46,000 pounds
- Max R/D GW of 46,000 - 50,000 pounds: 240 fpm
Night Operation on Water
NOTE
TRC and PH must be disarmed for water operations.
Night operation on water is permissible provided:
- Both DAFCS are operational
- Pilot and copilot RALT is operational
- Visible horizon is present at landing site
- 2+ highly visible, stationary objects are on the water surface to provide necessary visual cues for landing
Sea State Limits
- Max Sea State for operation on water: Sea State 2
- Small wavelets, crests of glassy apperance, not breaking
- Light breeze
- Wind: 4-6 knots
- Average wave height: 0.2 ft
Water Operation Time Limit
- Operation on water is restricted to 30 minutes total flotation tie without draining the helicopter.
Max Gross Weight for Water Operations
- Normal operations: 36,000 pounds
- Emergency rescue missions: 46,000 pounds
Water Taxiing Limitations
- Taxiing will not be conducted in water conditions above Sea State 1 or in wind above 6 knots.
- Fast taxiing will be conducted in a straight line only and to a maximum speed of 10 knots ground speed when the lower nose enclosure is left in the water.
Water Landing Limitations
- Water landings are prohibited when fuel in the main tanks is less than 50%.
Water Starting and Shutdown
- Rotor starting or shutdown will not be conducted when water conditions exceed Sea State 1 or wind exceeds 6 knots.
- Max gross weight for starting and shutdown is 28,550 pounds.
Air-to-Ground Towing
- Air-to-ground towing operations are prohibited.
APU Operation
- APU operation in flight is prohibited except during emergencies.
Anti-Ice Ground Limitations
Windshield Heat
- Windshield heat shall not be used above 24°C.
Single Point Refueling
- Maximum rate for pressure refueling is 300 gal/min at 55 psi.
ERFS: Capacity and Refueling Limits
- Maximum capacity of one tank: 825.5 gallons
- Usable fuel in one tank: 800 gallons
- Maximum internal pressure: 5 psi
- Maximum allowable suction defueling pressure: -11 psi
EGI GPS Limitations
- The EGIs are not approved by the FAA for use as a primary source of navigation during IFR conditions.
