Aircraft Instruments Flashcards
Describe the four-stroke cycle of a piston engine:
Intake - air and vaporised fuel is drawn in
Compression - compressed and ignited
Combustion - combust driving piston down
Exhaust - gases expelled
List the parts of a propeller:
Tip Trailing edge Leading edge Root Hub
What are the advantages of a piston engine?
Protected Easy to maintain Rapid change in rpm Cheap Common in training Short take off and landing runs Slow approach speeds
What are the disadvantages of a piston engine?
Less economical More fuel wieght Wear and tear from engine vibration Expensive fuel Low ceiling Noisy
How do jet engines work?
Air flows in, is compressed, combusted and passes through the turbine upon expulsion.
This discharge is a fast moving jet of fluid that generated thrust.
List the types of turbojet:
Turbofan
Turboshaft
Ramjet
What are the advantages of a jet engine?
Low vibration and noise Higher cruise ceiling Better performance Lighter Cheaper fuel
What are the disadvantages of a jet engine?
Set up cost
Delay in engine take up
Higher temperature and pressure stresses
High approach speeds and manoeuvre limitations at low levels.
What is a turboprop engine?
A turbojet engine with a propeller attached to the turbine.
What are the advantages and disadvantages of a turboprop engine?
Advantages: Quieter Efficient for commuter trips, e.i. Short field performance. Disadvantages: Low cruise level Expensive to manufacturer High frontal area - more drag.
What is an attitude indicator?
A gyroscopic instrument that indicates the pitch and angle of bank.
Allows for horizon reference in the absence of.
How is power supplied to gyros?
Electric motor or suction pump to create airflow.
What intervals does an AI measure in?
5 degree pitch intervals
10,20,30 and 45 degree bank marks.
How does an airspeed indicator work?
Airflows in to a pitot tube, where dynamic pressure is measured by removing static pressure from the static vent.
Hwo does an altimeter work?
Senses static pressure from static vent, located on side of the fuselage, which is used to measure the difference from the datum pressure and display the relative altitude.
How does a vertical speed indicator work?
Measures the rate of change of static pressure, which is displayed as feet per minute.
How does a turn and slip indicator?
Gyro measures rate of turn at rate 1,2,3 at 3, 6,12 degrees per second.
Inclinometer measures balance.
How does a direction indicator work?
Gyroscope that measures compass points via the aircraft’s horizontal plane.
Must be aligned with compass.
List flight instruments and their acronyms:
Radio magnetic indicator - RMI
Horizontal Situation Indicator - HSI
Attitude Indicator - AI
Electronic Flight Information System - EFIS
Primary Flight Display - PFD
Multifunction Display - MFD
Engine Information Crew Alerting System - EICAS
How is direction finding carried out?
ADF obtains bearings from NDB.
RMI displays the magnetic bearing from the aircraft.
Can be used for non-precision approach.
RMI can work with any two NDB or VORS
What does a DME indicator display?
Distance in nautical miles, ground speed in knots, time to station.
Establishing its range to the ground control.
How is ILS indicated on board?
Glidepath set, needle will indicate that flight is above or below.
Localiser set, needle will indicate that flight is port or starboard of.
What is a MLS?
Microwave landing system.
Functions similar to ILS using HSI wiich enables straight and curved approaches.
What onboard systems are used in En-route navigation?
INS
GPS
RNAV
How is En-route navigation processed?
Navigation aid fed into flight management system, crew input route data, flight director or autopilot navigate.
What are the factors affecting aircraft during take-off?
Runway conditions
Wind
Air density
Aircraft weight
What are the factors affecting aircraft during climb?
Aircraft weight Altitude Wind Temperature Air density
What are the factors affecting an aircraft during cruise?
Aircraft weight Speed Altitude Wind Temperature
What are the factors affecting aircraft during descent and initial approach?
Aircraft weight
Speed and rates of descent
Aircraft configuration
Wind
What factors affect aircraft during final approach and landing?
Aircraft configuration Weight Wind Air density Runway conditions
At what FL is fuel burnt less?
Higher FL
What ecological factors affect aircraft performance?
Fuel Jettisoning
Noise abatement Procedures
How can environmental impact be reduced?
More continuous climb and descent
Direct routing
Reducing holding
Cruising at higher FL
What are the pros and cons of analogue instruments?
Pros: Easy to read Rapid changes are easily detected Trends are easily noticed Better situational awareness during rapid changes Cons: Innaccurate Minor changes are difficult to detect Mechanical error
What are the pros and cons of digital instruments?
Pros:
Accuracy
Minor fluctuations easily detected
Cons:
Poor situational awareness during rapid changes
Some displays are difficult to read in bright light
What information is displayed on engine instruments?
Fuel quantity, flow, pressure and temperature
Oil quantity, pressure and temperature
Engine power and limitations
Electrical power
What might be indicated if fuel is lower than expected?
Blocked fuel line
Fuel leak
Imminent fuel starvation
What is engine pressure ratio?
The ratio of pressure difference between the front and the rear of the engine.
Should be highest at the rear.
What is the limiting factor of a gas turbine engine?
What are it’s limits?
Exhaust gas temperature
No lower limits
Mac upper limit 800°C above which the turbine melts
What other services are driven by the engine?
Electical
Hydraulic
Cabin pressurisation and air conditioning
How is aircraft electical power generated and what happens if it fails?
Generator or alternator
If fails reduces electrical services, might rely on battery power
What Hydraulic back ups are there?
Hand operated pump
Ram Air Turbine (RAT)
Nitrogen Blow Down Canister
What is EGPWS?
Enhaced Ground Proximity Warning System
Audible warning system that gives instructions to avoid terrain.
What are the disadvantages of EFIS?
Over reliance on leading to sudden increase in workload
What information is fed into EFIS?
Air data computer Flight management system Flight director Inertial Navigation system Weather radar Lightning sensors
What might cause an powerplant malfunction ?
Engine Failure/fire
Propeller damage
Foreign object debree/birdstrike
Poor inspection/maintenance procedure
What are the affects of powerplant malfunction?
Asymmetric flight
Climb performance hindered
Drift-down
Crew workload increased
What effect will a Hydraulic maltunction have?
Unable to use control surfaces
Can’t deploy landing gear
Brakes non operational
What are SOP?
Standard operating procedures
Standard steps that flight crew will follow to safely and effectively carry out operations.
Why do aircraft fly specified routes?
Noise restrictions
Airspace restrictions
Safe and orderly flow of traffic
By what figure do aircraft try and maintain their speed to?
Designated Mach No.
What affect does high altitude have on: Stability Turn rate and radius Speed range Climb/descent performance
Stability is reduced.
Turn rate is reduced and radios increased.
Speed range decreases with altitude.
Climb performance reduced
Descent performance reduced by overspeed.
How is top descent point calculated?
Height loss x 3.3 = distance in nm
