IFR Flashcards
What is the MEA?
Minimum en route altitude
Lowest published altitude between fixes that allows you obstacle clearance and navigational coverage
What is the MOCA?
Minimum obstruction clearance altitude
Provides obstacle clearance and navigation coverage up to 22nm of the VOR
What is the MORA?
Minimum off route altitude
Provides obstruction clearance within 10nm to either side of airway center lines and within a 10nm radius at the ends of airways
What is the OROCA?
Off route obstruction clearance altitude
Provides obstruction clearance with a 1,000ft buffer in non mountainous terrain areas and 2,000ft in mountainous terrain .
May not provide navigation or communication signal coverage
Attitude indicator - how does it operate?
Vacuum air driven gyro
Rigidity in space - shows bank and pitch information
Should show correct attitude within 5 minutes of starting engine
May have small acceleration/deceleration errors: accelerate shows slight pitch up and decelerate shows slight pitch down
Rolling out of 180 turn might show a slight turn in opposite direction
Talk about the heading indicator
Operates in rigidity in space. Vacuum air driven gyro
Only reflects heading, need to calibrate it with magnetic compass before departure
Normally powered by vacuum system in GA aircraft
Tell me about the turn indicators
Operates on the principle of precession
Turn coordinator shows rate of turn and rate of roll
Turn and slip indicators show rate of turn only
Altimeter
Pitot static instrument
Aneroid barometer shows the height above a given pressure level
Aneroid wafers expand and contract with changes in atmospheric pressure received from static port
Pressure setting displayed in Kollsman window
Above 18,000’ altimeter is always set for 29.92
High to low watch out below! Use caution when flying from high pressure to low pressure areas. If altimeter setting is not updated, altitude will indicate higher, causing the pilot to fly lower than desired. Flying from hot to cold areas results in the same error.
Talk about the VSI
Pitot static instrument
Normally a 6 second lag
Diaphragm inside instrument is connected directly to the static source. So the diaphragm pressure is the same as the pressure from the static port
Case of the instrument is also filled with static pressure, but connection between the case and static port is constricted by a calibrated leak
The calibrated leak limits the rate at which the pressure of the case can change
When the plane climbs or descends, the diaphragm pressure changes instantly, but case pressure changed slowly.
The difference in pressure shows the vertical speed
Plane climbs and diaphragm pressure decreases but case pressure decreases slowly. This results in case pressure having higher pressure than the diaphragm. Higher pressure squeezes diaphragm which makes VSI read a climb until pressures are equal
Tell me about the airspeed indicator
The airspeed indicator measures the difference between ram air pressure from the pitot tube and ambient pressure from the static port. The result pressure is called dynamic pressure
The static port connects and fills the case surrounding the diaphragm with static air. This will subtract out the static air that the pitot tube captured and allows dynamic pressure to be read on the instrument. This keeps the airspeed indicator reading the correct values no matter what altitude the plane is at.
Types of speeds
Indicated - indicated on the airspeed indicator
Calibrated - IAS corrected for instrument and position errors
Equivalent airspeed - CAS corrected for compressibility error
True airspeed - actual speed through the air. EAS corrected for nonstandard temperature and pressure
Ground speed - true airspeed corrected for winds
Static port blockage - effects on airspeed indicator
Indicates correctly only on the blockage altitude
Higher altitudes - airspeed shows lower than it should
Lower altitudes - airspeed shows higher than it should
Static port blockage - effect on altimeter
Will freeze in altitude where it was blocked
Static port blockage - effects on VSI
Freezes on zero
After verifying blockage in static port you should use an alternate static source or break the VSI window ( in which case; expect reverse VSI info )
When using alternate static source:
A lower static pressure is measured
Airspeed indicator will indicate faster than it should
Altimeter will indicate higher than it should
VSI will momentarily show a climb
Pitot tube blockage
Only instrument effected is airspeed
Ram air inlet clogged and drain hole open: airspeed drops to zero
Both air inlet and drain hole clogged - airspeed indicator will act as altimeter and no longer be reliable
Magnetic compass errors and limitations
DVMONA
Deviation - magnetic fields in aircraft cause by electronics cause deviation (use compass deviation card)
Variation - the difference between true and magnetic directions is called variation
Magnetic dip - compass tends toward the magnetic pole the closer you get to it
Oscillation - magnetic compass bounces around because of turbulence
North/south turning errors - UNOS - undershoot north overshoot south
Acceleration/deceleration errors - ANDS - accelerate north, decelerate south
What is the AHRS?
Attitude heading and reference system
Attitude indicator
HSI
What is ADC?
Air data computers
Replaces the mechanical pitot-static instruments.
The ADC receives input from the pitot, static and outside temperature ports
Computes airspeed, true airspeed, vertical speed, and altitude
What is the PFD?
Primary flight display
Displays flight data such as altitude, attitude, airspeed, VSI, and rate tapes
What is the MFD?
Multi function display
Displays a variety of information such as moving maps, aircraft system status, weather and traffic.
Can also be used as a backup for other displays
What is the FMS?
Flight management system
Receives inputs from various sensors and provided guidance to the autopilot and flight director throughout the flight
The FMS also automatically monitors and selects the most appropriate navigation source for accurate positioning (GPS, VOR/DME etc.)
What equipment is required if you are operating for hire over water and beyond power off gliding distance from shore?
An approved floatation device for each occupant
At least one pyrotechnic signaling device
What is DME?
Normally tuned automatically with a paired VHF station (VOR/LOC)
The airborne DME unit transmits an interrogation signal, then the ground DME facility receives and replies to the interrogation
Airborne unit calculates the slant range distance to the station based on reply time
Slant range error is negligible at 1NM from the DME station per 1,000ft
So if you’re flying at 5,000’ above the DME station (AGL), and you’re at least 5NM away from the station, your DME readout will be accurate.
What is a VOR?
VHF OMNI DIRECTIONAL RANGE
Ground station that provides 360 degree information in the form of radials expressed as magnetic headings
Full scale deflection is 10degrees
Pilot must verify correct and useable VOR station with Morse ID before using it
R means you transmit on that frequency and listen on the VOR frequency to contact FSS
VOR limitations
Cone of confusion (flying over top of it)
Reverse sensing (if used incorrectly)
Requires line of sight between aircraft and station
VOR receiver checks
Every 30 days if flying IFR
VOT +- 4 (180 TO or 360 FROM)
Repair station +-4
VOR ground checkpoint +-4 (180 TO or 360 FROM)
VOR airborne within +-6
Dual VOR cross check +-4
Above a prominent ground landmark on a selected radial at least 20nm from VOR, flying at a reasonable low altitude +-6
VOR check sign off
DEPS
Date
Error
Place
Signature
What is the max airspeed on holds?
6,000’ or below : 200kts
6,001-14,000’ : 230kts
14,001 and above : 265kts
Mandatory reports under IFR
MARVELOUSVFRC500
Missed approach Airspeed +- 10kts or 5% change of filed TAS (whichever is higher) Reaching a holding fix (report time and altitude) VFR on top ETA changed +-2 min ** Leaving a holding fix/point Outer marker ** Unforecasted weather Safety of flight Vacating an altitude FAF ** Radio/nav approach equipment failure Compulsory reporting points ** 500 - unable to climb/descend at 500fpm
** only in non radar environment
Position report items in a non radar environment
IPTANES
ID Position Type of flight plan Altitude ETA and name of next reporting fix Name only of the next point along route Remarks
Rule of thumb when to start your descent
3 miles per 1,000ft
Flying at 7,000. Need to get down to 1,000.
6,000 feet to lose. 6x3=18 miles
You can add 3 extra miles in for a buffet
What is GPS?
What’s is GNSS?
Global Positioning System
Global Navigational Satellite System
Tell me about GPS
The constellation of satellites consists of a minimum of 24 satellites so that at least 5 satellites are in view at any location on earth
The aircrafts GPS receiver calculates the distance to a GPS satellite based on the time lapse since the broadcast time stamp, and the time it was received.
How many satellites required for 2D position? 3D position?
3 satellites for 2D (lat and long)
4 satellites for 3D (lat, long, altitude)
What is RAIM?
Receiver Autonomous Integrity Monitoring
Is a function of GPS receivers that monitors the the integrity of the satellite signals
RAIM (fault detection) requires 5 satellites, or 4 satellites and an altimeter input
RAIM (fault exclusion) eliminates a corrupt satellite and needs a total of 6 satellites for this to work
How is GPS CDI deflection different from a VOR CDI deflection?
GPS CDI deflection shows distance, unlike a VORs CDI which presents angular distance off course in degrees
What is WAAS?
Wide Area Augmentation System
Ground stations measure GPS errors and produce correction signals. These corrections are broadcasted back to the satellite segment from which they are bounced back to aircraft GPS WAAS receivers to improve accuracy, integrity, and availability monitoring for GPS navigation.
