NATOPS Chapter 14 Flashcards
Hangaring in Cold
If hangar space is available, aircraft should be kept in a heated hangar when OAT is forecast below 0C (32F)
Ice Removal
Shall never be done by scraping or chipping. Remove ice by applying heat or approved deice fluids
PCL Hard to Move
May be indicative of frozen PAS or PAS cable. Do not force PCL movement as this may damage the PAS cable
Starts in Extreme Cold (-40*C)
Oil pressure may remain at 0 for about the first 20-30 seconds after initiating the start. Abort start if there is no oil pressure within 1 min after initiating a start
Oil Bypass
Indicator has thermal lockout below 38*C preventing PDI from popping
OIL FILTER BYPASS may appear during cold starts–disappears above 38*C
Engine Start (Cold Overnight)
Watch for rise in TGT within 40 sec. If no TGT rise is evident, prime the engine and attempt another start
If there is no overboard fuel flow, inspect for ice in the sumps and filters
Icy Surface
Recommended to use no-rotor brake start procedures to avoid rotation from rapid increase in torque
Warmup and Control Exercise
- 17C - -31C
- 31C - -40C
Warm up engine at idle for 3 min; during warmup position cyclic control 1in forward of neutral and move tail rotor pedals alternately 3/8in
Same, but position cyclic 5/8in forward, gradually moving to 3in forward; move each tail pedal 1/8in gradually moving to 1/2in
Taxiing in Cold
Should not be accomplished until all engine and system pressures are within normal limits
Slow speeds, wide radius turns
Do not exceed 15kgs
MD/FDs in Cold
When powering up MD/FDs in temps of 0*C or colder, the displays will illuminate within 15 seconds but up to 15 minutes may be required before full performance is available
Transducer in Cold
For in-air temps >5C, normal charging time before unfolding or transmitting is approx 10 min after mission power applied (ST/R powered on); in-air temps of <5C may take up to 45 min before successful array unfolding or transmissions
If battery doesn’t reach at least 60% within 1 hr of applying power for temps above 5C or 1 1/2 hrs for temps less than 5C battery may be unable to support normal ops
The inability of battery to consistently reach a charge of 60% may indicate a battery failure (typical codes include 1111 or 1174 and DOME PING ABORTED)
TIME TO PING not decreasing indicates failure to charge (execute procedure); if doesn’t fix charge, battery pack may have failed and dipping ops must be suspended
Snow Precautions
May have no visual horizon over large expanses of snow
Avoid loose, powdery snow to minimize visibility restrictions
Takeoffs into fog or low clouds when temp is at or near freezing could result in engine air inlet icing–climb speeds should be higher than normal under such conditions
Snow Landings
Running landings are recommended on loose snow
Maintain enough airspeed to remain ahead of snow cloud but not be over approx 15 knots at touchdown
Be ready to takeoff immediately if a wheel should hang up or break through crust–do not reduce power until it is positively determined the aircraft will not settle
When shutting down on icy surface, advisable to let the rotor coast down to avoid possible aircraft rotation by a rapid application of rotor brake
ECS Usage
ECS - HOT, max torque available may be reduced by approx 5% per engine–fuel flow will increase approx 45lbs per hour per engine
Before Leaving Aircraft
Protect wheels from freezing to ground by towing/taxiing onto planks or sandbags
Leave parking brake off–chock and chain
Open scuppers on cockpit windows
Drain moisture accumulation from sumps and strainers
Install engine inlet plugs after shutdown to prevent accumulation of ice and snow in engines
OAT Gauges
Not calibrated and may provide false information
Flight Into Icing/Shedding
Into known icing without deice equipment is prohibited
Into forecasted or known moderate or severe icing is prohibited
Shedding from rotors and components presents a hazard to personnel during landing and shutdown
Shedding from main rotor may strike tail rotor during rapid descents following flight in icing conditions
Pooled Water
Water pooled in intake ducting will freeze and may result in FOD–must be removed prior to freezing
Intakes shall also be checked for ice on preflight
Anti-ice/Deice
Pitot Heat
Shall be turned on when OAT reaches 5*C or below in visible moisture
Shall be turned on when OAT less than 5*C or when visible moisture is present
Ice Damage to Engine
May be characterized by high-pitched noise with no associated power loss or secondary indication
Significant power loss and increased fuel consumption can be expected as a result of actuation of the engine and engine inlet anti-ice systems
Initial Ice Accumulation
Will be noted on windshield wiper arms, mirror support brackets, main landing gear and external stores
Ice Rate Detector
No2 engine cowling activates ICE DETECTED and turns on aspirate heater to shed the ice
Ice melts and caution disappears
Frequency at which ICE DETECTED cycles on and off may give indication of icing severity
Torque Increase
Additional torque increase up to 14% per engine may be experienced due to ice buildup during normal operations of blade deice system
WARNING Ice accumulation resulting in a 20% increase in torque indicates normal autorotational rotor rpm may not be attainable should a dual engine failure occur
Increase over 10% matched torque should result in urgent consideration to vacate the environment unless task is considered essential
If torque increases 20% above that required for level fligh at the airspeed being maintained prior to entering icing, exit the icing environment or land the aircraft as soon as possible
Asymmetric Shedding
If blade deice is not operating, asymmetric shedding may cause imbalances which may result in severe vibrations
These should subside after 30-60sec–some impact damage can be expected during flight into icing
Blade Fold
Potential exists for incomplete blade fold following flight in icing
Visually ensure all blade fold microswitch contact surfaces are free of accumulation prior to attempting blade fold sequence
Lightning Strike
A severe lightning strike to the aircraft is likely to result in the loss of all electrical power sources except the battery (including APU generator even if it not operating at the time) and damage a majority of electronic circuits
Due to electrical system design, battery power may only be available for the components on the battery utility bus (only backup instruments available)
Lightning strike that induces voltages in the engines may damage DECU and and possibly other related components
Turbulence
Moderate - limit airspeed to blade stall speed minus 15 knots
Light - limit airspeed to blade stall speed minus 10 knots
Set and leave collective setting using AI as primary pitch instrument
Pitot static may vary as much as 40 KIAS–maintaining collective position and level flight, airspeed will remain relatively constant
Starting/Stopping Rotors in High Wind
Hold cyclic into the wind and increase RPM immediately to prevent excessive flapping
Hold cyclic into wind to reduce bumping against droop stops–apply rotor brake when rotor speed is below 40%
Nose Bay Water Intrusion
May cause AFCC failure
Hot Weather
Requires more power
Fuel densities will decrease as ambient temp rises, resulting in decrease in operating range
High humidity increases DA and effectively reduces efficiency of rotor system. For every 10% increase in relative humidity, the DA increases approx 100ft
Oil Pressure in Hot Weather
If engine oil pressure falls into red range or ENGINE OIL PRESS caution appears when PCL is in IDLE, slightly advance PCL
If oil pressure returns to yellow range and caution disappears, engine oil pressure is acceptable
Dust
Consider towing for takeoff because sand and dust may cause severe damage
May cause ICE DETECTED caution
Check for sand and dust in control hinges, actuating linkages and inspect tires for proper inflation (high temp may over-inflate)
Check oleo struts, especially near cylinder seal and remove accumulation with clean, dry rag
Get airborne as quickly as possible (especially if taxiing) to limit ingested dust and sand and minimize erosion of rotor blades
Execute steep to no hover landing
