NATOPS Extreme Wx Operations Flashcards
Tire, landing gear strut, and accumulator air pressures ______ as the temperature decreases.
Decreases
If hangar space is available, the aircraft _______ be kept in a heated hangar when OAT is forecast below ____.
Should
0 degrees Celsius
Ice removal shall never be done by ________. Remove ice by ____________.
Scraping or chipping
Applying heat or approved driving fluids
A PCL that is difficult to move may be indicative of a frozen ____________. Do not _____________, as this may _________.
PAS or PAS cable.
Force PCL movement as this may damage the PAS cable
Flight controls many be difficult to move after the aircraft has been cold soaked. If the controls are not sufficiently free for a safe start and low-power warmup, ___________.
Heat the affected controls
It is normal to observe ______ engine oil pressure during initial starts when oil is cold. _____________ until oil pressure is within in limits.
Oil pressure should return to the normal range after operating _____.
High
Run engine at idle
5 minutes
During starts in extreme cold weather (near -40 deg C), the following oil px characteristics are typical:
- Oil px may remain at zero for about the first 20-30 seconds after initiating the start. Aborts the start if there is no oil px within 1 minute after initiating a start.
- Once oil px begins to indicate, it will increase rapidly and exceed the prescribed 100 psi limit and will decrease as temperature rises. This condition is considered normal. The time for oil px to decrease to 100 psi or below will depend on the severity of the ambient temperature, but it should occur within 5 minutes after starting the engine. Do not advance PCL to FLY until engine oil px is indicating normal.
- Oil px may increase above the max px limit if the engine is accelerated above idle while oil temperature is below normal operating range. The px will decrease to within the normal operating range as the oil temp increases. The impending bypass indicator has a thermal lockout below 38 deg C to prevent the PDI button from popping. The OIL FILTER BYPASS caution may appear during cold wx starts. When engine oil temperature reaches approx 38 deg C, the caution should disappear.
When starting an engine that has been exposed to low temperatures overnight, watch for a rise in ______ within _____ seconds.
TGT
40
During cold-wx operation, allow ________________ to bring transmission oil temperature up to a desired operating range.
A longer warmup time
When on an icy surface, what type of start should you do?
No-Rotor Brake Start
Engine start at temperatures between -17 and -31 deg C
Warm up engine at idle for 3 minutes. During engine warmup, position cyclic control 1 inch forward of neutral and move tail rotor pedals alternately 3/8 inch.
Engine start at temperatures between -31 and -40 deg C
Warm up engine at idle for 3 minutes. During engine warmup, position cyclic control 5/8 inch forward, gradually increasing cyclic movement to 2 inches. Move each tail rotor pedal 1/8 inch and gradually increase movement to 1/2 inch.
For engine warmups, consideration should be given to using what type of start procedure?
Rotor Brake start
The helicopter should not be taxied until ____________.
All engine temperatures and system pressures are within normal limits
What happens to the mission/fight displays in cold wx?
Slower to respond, may take up to 15 minutes for full performance
TA battery charging cold wx
In-air temperatures > 5 deg C: normal charging time before unfolding the array or transmitting actively is ~10 minutes after mission power is applied
5 deg C or below: up to 45 minutes may be required before successful array unfolding or active transmissions
*If charge does not reach/maintain a 60% charge, may indicate a battery failure/battery that can’t support normal ops to include active transmissions and unfolding the array
Battery Failure Fault Codes TA
1111 (Array Fold/Unfold Status Fail)
1174 (ESD Sequence Fail)
DOME PING ABORTED
When flying over large, unbroken expanses of snow, the pilot should be aware that there is ______.
No visible horizon
Takeoffs/landings snow
Running takeoffs are permitted if ground speed is held to 60 knots or below on level terrain
Running landings are recommended when landing on loose snow (fast enough to remain ahead of snow cloud but not over ~15 knots on touchdown)
Blowing snow on takeoff may require….
ITO procedure
Effect of ECS HOT, engine anti-ice on, APU on
ECS HOT: tq available reduced by ~5% per engine; fuel flow increase by ~45# per hour
Engine Anti-Ice on: max tq available reduced by up to 18% per engine/49% per if inlet anti-ice valve has malfunctioned
APU to power ECS: increase fuel consumption by ~150# per hour
Rotor brake and shutting down on icy surface
Advisable to allow the rotor to coast down to prevent a/c rotation due to rapid application of the rotor brake
Landing on snow
Slowly decrease collective until the a/c is firmly on the ground. Be sure a/c is not going to settle before lowering collective completely. Be ready to takeoff immediately.
OAT gauges are ______ instruments and may provide ________.
Non-calibrated
False information
Ice damage to the T700 engine characterized how?
High-pitched noise with no associated power loss or secondary indication
If icing conditions are encountered or the ICE DETECTED caution appears due to suspected icing conditions:
- Immediately turn on all anti-icing equipment
- Seek condition where icing is not present
- Land as soon as practicable
Initial ice accumulation will be noted where?
Windshield wiper arms, mirror support brackets, main landing gear, external stores
ICE DETECTED cycling
May give an indication of icing severity level
Cycles off once ice is heated/melts off
Icing tq increases
14%: ice build up during NORMAL operation of the blade de-ice system
20%: normal auto rotational rotor rpm may not be attainable (inc in 20% for fixed airspeed, exit icing and land as soon as possible)
Increase in 10% match tq: urgent consideration to vacate the environment unless the task is essential
____________ of short duration can be expected in the ______________ during normal de-ice cycles.
Moderate vibration levels
Controls and airframe
Droop stop/antiflapping restrainers freezing
Rotors droop to 4’ above the ground on shutdown
Strong gusty winds may cause excessive flapping and present additional hazard of potential contact with the aft fuselage
When shall pitot heat be turned on?
OAT 5 deg C or below
OR
Visible moisture present
Failure to turn on pitot heat
Erroneous airspeed indications and erratic or downward programming of the stab/loss of aircraft control
A severe lightning strike to the aircraft is likely to result in the loss of…
All electrical power sources except the battery (including the APU gen even if not operating at the time)
Battery power may only be available for operation of components associated with the Battery Utility bus
Possible damage to EDECUs
With the loss of all electrical power, the only remaining instruments still available to the pilots for an emergency landing would be the __________.
Standby instruments
Airspeed recommendations for moderate/light turbulence
Moderate: blade stall speed - 15 knots
Light: blade stall speed - 10 knots
Flight instruments/techniques for flying in turbulence
Adjust collective for recommended air speeds and then held contains. AI is the primary pitch instrument. Maintain constant collective and a level flight attitude on AI
Airspeed indications may vary as much as 40 KIAS.
Starting rotors in turbulent air
Hold cyclic into the wind and increase the rotor rpm immediately to prevent excessive flapping of the blades
_________ to reduce the tendency of the blades to bump against the droop stops.
Hold the cyclic into the wind
______ will decrease as the ambient temperature rises, resulting in a decrease in operating range.
Fuel densities
High humidity increases the DA and effectively ______ of the rotor system.
Reduces the efficiency
(Hot wx) During ground ops, if engine oil px falls into the red range and/or ENGINE OIL PRESS caution appears when the PCL is ___________ , slightly advance the PCL. If the engine oil pressure ___________ and the ENGINE OIL PRESS caution disappears, engine oil px is acceptable.
In the IDLE position
Returns to the yellow range
Takeoffs in sandy/dusty environment
Consider towing the helo to the takeoff position. Severe damage may be caused by sand and dust.
High temperatures may cause _______ of tires.
Overinflation
Engine starting hot wx
If possible, should be made from hard, clean surface and into the wind
When it is absolutely necessary to taxi in sand and dust…
Get the helicopter airborne as quickly as possible and climb as rapidly as possible
Dust storms
Avoid when possible. Excessive dust and grit in the air will cause considerable damage to internal engine parts and erosion of the main rotor blades.
Best way to land in sand/dust/brownout
Steep approach to a no-hover landing (then shut down as soon as practicable!)
