7.17 Aircraft handling and storage Flashcards
What is aircraft taxiing?
Controlled movement of an aircraft on the ground, using its own power, during the pre- flight and post- flight phases of operation
How is the aircraft steered during towing operations?
hydraulically trough the use of the towing bar/ arm attached to the nose wheel of the aircraft
What three things does marshalling do?
- Ensures smooth flow of traffic
- minimises risk of collisions
- facilitates safe positioning of aircraft
Where should the marshaller be for fixed wing aircraft?
on the left side, where best seen by the pilot
Where should a marshaller be for a helicopter?
Where a marshaller can best be seen by the pilot
What provides the signals to be used by a marshaller?
ICAO Annex 2 (rules of the air)
What are the qualification requirements of a marshaller?
- trained
- qualified
- authorised by the local authority approved organisation
What does the marshaller need to wear/ use for visibility?
- distincitve fluorescent vest
- daylight: fluorescent coloured wands, table tenis bats or gloves
- night or low visibility: illuminated wands
What is the turn left signal?
With right arm and wand extended at a 90-degree angle to body, make ‘come ahead’ signal with left hand.
How many engines need to be running for taxiing?
- normally all
- in exceptional circumstances you can taxi with one
How is the steering nose- wheel steering system controlled?
by a hand wheel to a max steering angle of +/- 70 degrees
What is used for taxi steering if nose- wheel steering isn’t available?
differential use of LH and RH landing gear wheel brakes
What lights must be one during taxiing and towing?
Nav lights and beacons
How are aircraft with tail wheels generally towed?
- Attaching the towbar to the main landing gear
- Towing in reverse can be done by attaching the towbar to the tail wheel axle
What has to be done when an aircraft with a tail wheel is towed?
Tail wheel must be unlocked or the locking mechanism might break
How is the towbar attached to aircraft with tricycle landing gear?
Towed forward by attaching it to the axle of the nosewheel
What acts as a shock absorber in towing bars to avoid snatching movements being transmitted to the aircraft structure?
- Normally a large spring
- A shear pin prevents excessive loads between the tractor and NLG
How are towing bars stopped from being drawn behind the towing vehicle or in to the aircraft?
They have small wheels that are raised and lowered hydraulically by a hand pump
What are the most common towbars?
- Multi- head towbars
- Allows the operator to swap out the head attachments to suit a variety of aircraft
How does the towbarless tug work?
Uses hydraulic actuators to support the landing gear nose and lift it completely off the ground
What are two advantages of remote control tugs?
- No tractor and towbar length so provide increased parking in hangars
- Increases flexibility as the tug can be placed behind the nose wheel to steer from underneath the belly instead of in front of the wheels
Why may bridles be used to tow the aircraft?
- if the ground is to bumpy and will strain the NLG too much
- the bridles are attached to each MLG
How should steering be done when towing using bridles?
Attach a steering arm to the nose wheel (rather than differential movement of the tugs)
When should a tail walker be assigned?
When sharp turns are to be made or if the aircraft has to reverse
What are the locking scissors set to on a steerable nosewheel for towing?
locking scissors are set to full swivel
Where is the manufacturers maximum turning angle usually found?
Painted on the NLG shock strut
What should you do as soon as an aircraft has been parked in a hangar?
Statically ground it
What tests are performed on jacks?
- gear retraction
- extension
- free fall tests
What type of jack is used for wheel changes?
Axle/ bottle jack
What jack is used for arc lifts?
- Bipod jacks
- A hydraulic unit has two fixed legs and one adjustable leg
What is a tripod jack used for?
- used for lifting the entire aircraft up, vertical lifts
What are the three core parts of tripod jacks?
a tubular steel tripod strucutre with:
- caster wheels
- hydraulic cylinder
- hydraulic pump assembly
How many inches should the hand wheel safety nut be away from the top of the jack when raising or lowering aircraft jacks?
1 inch
What do the safety devices on jacks prevent?
Prevents the rams moving down inside the jack body incase of a hydraulic system failure
What ATA chapter contains info on jacking?
ATA chapter 7
When jacking an aricraft up, how many turns from the jack body should the collar be wound own?
two to three turns is generally acceptable
What is attached to lighter aircraft to anchor is to the hangar floor?
A tie down ring at the rear fuselage anchors the empennage down
What needs to be done to the wheels not being raised when using an axle jack?
- chocks must be placed fore and aft of them
What is the first operation when dejacking an aircraft?
Raise the collars a few turns so the jack rams can contract in to the jack body
How many people must operate each jack on larger aircraft?
Two people
Where are pinch points on aircraft jacks?
between the top of the jack and the threads on the ram
What can be used for additional stability during jacking?
- tail stand
- Nose stand
What is shoring?
- Also known as trestling
- Supports the aircraft and relieves stresses
What devices might an aircraft have to show the aircrafts level during jacking?
- spirit level
- plumb bob
D4 position corresponds to longitudinal angle of 0 degrees
What must be done to chocks when refuelling?
moved out
How do you determine which direction the aircraft is parked and tied down?
Prevailing the forecasted wind direction
What direction is the aircraft parked in relative to the wind?
Parked in to the wind
How much slack must be provided to manila ropes when using them to tie down smaller aircraft?
25mm/ 1 inch
How can heavy aircraft be tied down?
use of rope or wire
How many tiedowns are used to secure heavy aircraft?
as much needed depending on weather conditions
What is “mooring”?
Securing the aircraft
What ATA chapter is parking and storage under?
ATA chapter 10
Where are protection devices required during storage/ parking of aircraft?
- inlet and exhaust ducts of APU
- sensors and probes
What are the normal maintenance tasks for a return to service up to 2 days?
- safety devices and blanks removed
- any system deactivated for parking is to be activated
- visual inspection for damage and leaks to be done
- sign off the original entry in the logbook
What can be done to help prevent microbiological corrosion in fuel tanks?
Fuel tanks can be filled to full
When should visual inspections be done if an aircraft is parked for more than 2 days?
at seven and 15 day intervals
How can the deterioration of main wheel assemblies be prevented?
cover them
What aircraft components might require functional tests during parking?
- Nose wheel steering
- Braking systems
- Engine and APU
- air conditioning systems
What position must the THS be set to during parking?
Neutral
What is a disadvantage of using adhesive tape?
discolouration of the aircraft paint or transfer of colours
What can fuel tanks fuel be mixed with to prevent microbiological corrosion?
can be mixed with inhibitors
When must tyre inflation pressures be checked? (parking)
For periods longer than 20 months.
Parking: What do weekly checks consist of?
- visuals for leakage and any evidence of bird nests
Parking: What must be done in addition to weekly checks during bi-weekly checks?
- Move aircraft to prevent brinelling of main wheel bearings
- check pressure extension of landing gear oleos
Parking: What must be done during one month checks, in addition to the weekly and bi weekly?
- opening all doors (including cargo compartmnts) and reapplying protective greases to door seals
- Operating air conditioning system via low or high pressure ground connections to remove moisture
- test of av systems
- testing of ice protection systems
What two categories do aviation fuels fall in to?
- aviation gasoline
- turbine fuels
How is AVGAS graded?
by their octane number
What is the octane number of fuel?
Fuels ability to resist knocking.
Higher the number, the better it is at resisting the knock.
What are the different grades of AVGAS?
80- RED
100 - GREEN
100LL (low lead) - BLUE
What type of aircraft is AVGAS used in?
Piston engine aircraft
what are the types of turbine fuels w their freeze points?
Jet A: -40°C
Jet A-1: -47°C
Jet B: -50°C
What colour are turbine fuels?
colourless or light straw colour
How high can refuelling pressure be?
50 psi
What is the maximum defuel pressure?
11 psi
What can the refuelling rate be as high as?
1000 gallons (4546L) per minute
What is the most commonly used refuelling method for larger aircraft with a single point fuelling system?
pressure refuelling
What are the advantages of pressure refuelling?
- decreased time to refuel
- limits contamination
- reduces chances of static electricity igniting the fuel
How is pressure refuelling carried out?
With refueling receptacles in the leading edge
Can fuel from pressure defuelling be put in to another aircraft?
NO, must be put in to a defuel bowser
But different companies have different rules
What are two essential safety precautions when refuelling or defuelling?
- grounding and bonding of both the aircraft and the fuel truck
- respecting the fuel safety zone
Who might ensure the escape path for fuel vehicles in smaller operations?
Aircraft engineer
What is a NACA duct used for?
- Found in each fuel tanks
- Fuel can flow out and on to the ground if the vent tank is full
What is the safety zone when defuelling and refuelling?
Three metres around the area under the NACA vents, overpressure protectors and refuel couplings.
Where must no smoking signs be placed during fuelling?
At a minimum distance of 15m (50 ft) from fuelling equipment and ac vent tanks
Where must a fuelling zone be placed prior to fuelling operations?
at least 6m from filling/ venting points on both the aircraft and fuelling equipment
What fire extinguishers are recommended when fuelling?
- carbon dioxide
- Foam extinguishers
Where should GPUs be when refuelling or defuelling?
As far as possible
How long should you wait before doing a drain check on turbine fuel?
as long as possible as it takes a long time to set
What is used to perform a water check on fuel?
Shell water detector capsules
What is aircraft performance certification based on?
The aircraft having an uncontaminated or clean structure
When is an aircraft in cold- soak configuration?
- When it’s parked in cold weather
- the OAT is lower than 0°
- no supply of power to the aircraft
What does the amount of icing on aircraft depend on?
- surface temp
- surface condition
- duration of icing conditions
- amount of moisture present in the atmosphere
What are the critical surfaces that must be clear of ice before flight?
- wings
- vertical stabiliser
- horizontal stabiliser
- rudder
When does most icing occur?
Between 0°c and -10°c when supercooled water droplets freeze on impact with a cold surface
What is the lowest temp ice can still form at?
-40°c
What clouds give lots of icing?
Cumulus clouds
What type of ice results in the most skin friction?
Rime ice
How are deicing fluids usually applied?
Usually applied heated through a high pressure spray system
What is one- step method for deicing and anticing combined?
Deicing part: with heated anti icing fluid mixture
Antiicing part: fluid that remains
What is the two step method if icing and deiicing combined?
- de- ice the aircraft
- follow immediately w anti- icing procedure
What must be done if the aircraft doesnt fly within the holdover time?
repeat removal of the ice and preheat the engines
What are type I fluids?
- used for de- icing
- limited effect when anti - icing bc of low viscosity
What position do the flaps/ slats have to arrive in for an inspection to be necessary?
If the aircraft arrives at the gate with the flaps/slats in a position other than fully retracted, they must be inspected and, if necessary, de-iced before retraction.
What are type II fluids?
- anti- icing
- higher viscosity so doesnt flow off aircraft until it reaches 100kt
- good for larger aircraft
What are type III fluids?
- Compromise between type I and type II fluids
- For smaller aircraft at less than 100kts
- Bright yellow
Why are type IV fluids better than type II?
- Same as type II but have longer holdover times
What do all de/anti- icing fluids contain?
- Monoethylene- glycol
- Diethylene-glycol
- Monopropylene- gylcol
What do type I fluids contain a 20% mix of?
- inhibitors to resist corrosion and increase flashpoint
- Water
- Wetting agents so it can form a uniform film over the aircraft
What is 50% of type II, III and IV fluids made up of?
- inhibitors
- water
- wetting agent for a unifrom film over the surfaces
- thickening agents
How are the different types of de/ anti- icing fluid identified?
Colour coded
When does the hold over time start from?
Just deicing: From the start of the application
Two step: from the start of the anti- icing
What must an anti- icing code contain?
- type of fluid
- percentage of fluid to water (for type II and IV only)
- time the application began (preferably local time)
What affects the time of protection against icing:
- Very bad weather conditions
- High wind speeds and jet blasts
- Wing temperature being below OAT (Outside Air Temperature)
- Age and condition of the fluid
- Method of application
What has to be done before making an external electrical connection to aircraft?
Ensure the master switch on the GPU is off
What shows that external power is on and connected?
flight deck indicator
What is each of the three pins in a DC plug for?
- one positive pin
- one negative pin
- smaller earth pin thats also a relay control pin
What happens when the external master switch is switched off?
the relay resets, external power is switched off, and internal power (batteries) are switched onto the busbars.
How should the lead of ground electrical power units be?
the socket lead must be extended to near its full length but not stretched to place any undue stress on the aircraft electrical receptacle.
How is DC supplied to an aircraft (externally)?
a set of batteries mounted on a trolley or an engine-driven dc generator can be required
What is the AC supply for aircraft?
115v AC
400 Hz
3 phase
How does a diesel engine powered GPU produce electrical power?
- Has an internal combustion engine that drives an alternator or engine to produce power
When is an engine driven APU useful?
when an aircraft’s own APU is not operational or when additional power is required beyond what the aircraft’s APU can provide
How does a battery powered GPU provide electrical power?
- Self contained mobile units powered by dc batteries
- Uses an inverter to supply AC voltage
What is a limitation of a battery powered GPU?
Can only support 10-12 aircraft rounds
How is the limitation of battery powered GPUs addressed?
Charge the unit whilst delivering power to the aircraft
What supplies the utility GPU with power?
- connect it to a socket supplied by the mains grid
What does the utility GPU convert the main supply to, from?
standard grid supply: 110/220v AC 50/60 Hz
converts it to: 400Hz and 115v AC
What are the six pins in the utility GPU power supply socket for?
three large pins: supply of the three phases
Fourth pin: ground/ earth connection
two small pins: dc control pins that operate relays to switch in/out three external supply
What is connected if more power is required once the primary connection has been made?
The secondary connection
What equipment/ indications do power supply panels have?
- Three external ac power circuit breakers
- dc control circuit breakers
- Power connected/power ON lights
- Panel illumination lights
- Inter phone socket
- Pilot’s call button
When is a hydraulic test rig required?
When the engine or APU cant be run to supply hydraulic pressure to hydraulic systems
What prevents fluid loss of hydraulic rigs and the aircraft?
Hydraulic quick- disconnect couplings where the rig connects to the aircraft
How are hydraulic test rigs driven?
electrically or driven through a diesel engine if the exhaust is vented outside
What pressure and flow does a hydraulic test rig produce?
the same pressure and flow rate as the aircraft engine-driven pumps
When should hydraulic spilled be cleaned?
immediately
What does an Air cart provide?
provide low pressure to start the engines and heat and cool the aircraft on the ground
How much pressure does an air cart provide?
50 psi
Where does an air cart get its pressure from?
APU built in to the cart
bleed air from the APUs compressor
Where should a ground cart be placed?
As far as possible
What certificate of servicabilities must be checked when checking the aircraft system before connecting a ground cart?
Certificate of serviceability in relation to its :
- motive power
- exhaust emission
- quality and rate of air supply.
What can be done to save time when an aircraft is to be parked in snow or ice conditions?
- paint around doors and frequently opened access panels with inhibited glycol antifreeze components
- painted on surfaces under snow covers
- used on wings or tails
What can be done if snow is expected?
- Park the aircraft on planking rather than packed snow
- Or put sand near the wheels
What position must flaps and slats be in during cold conditions?
retracted
What position should moveable horziontal stabilisers be in, in cold conditions?
set to approx 0
What is the best way to remove snow?
Sweep off as much as possible. Either by dragging a line over the fuselage or using a brush or a broom on wing and tail surfaces.
What mind of hot air is most effective for deicing?
A large flow of warm air over a blast of hot air
What temperature should any air being used to deice be?
Any temp under that of boiling water
Do turbine engines require oil dilution, priming or lengthy warm up?
No, just need to check engine compressor rotors for any ice
What is necessary when aircraft is operating in sand conditions whilst parked?
- blanks and covers must be fitted
- window transparencies can require covers to prevent corrosion
Sandy conditions: What can be done to prevent particle ingress?
Extra filtration of air conditioning systems
What ATA chapter covers conditional inspections?
Chapt 5
Sand and dust conditions: What additional spares must be carried?
Filters, bearings and seals
Hot weather operations: What are the principal difficulties encountered?
- High Turbine gas temps during engine starting
- over- heating
- slower cooling of brakes
- linger take off and landing distances bc of the low density air
- Fuel tanks water separation and condensation of atmospheric moisture
Hot weather conditions: What should be done when starting electric systems?
Start the air conditioning system to dry up moisture and prevent fungi
Raining conditions: What must be done if the doors have to be opened?
- all entrance drains must be clear and surrounding areas well sealed
