Instrument Procedures - Approaches Flashcards
How many categories of aircraft exist?
5 categories
What is approach speed based on?
VAT Speed
How is VAT speed calculated?
1.23 x VS1G
Aircraft Categories and approach speeds.
A - <91
B - 91/120
C - 121/140
D - 141/165
E - 166/210
MSA / TAA OBS Clearance
300m/ 1000ft within 25nm of navaid for approach.
When can we descend below MSA?
ARPT/TERR in visual contact
Aircraft is being radar vectored
Aircraft is flying a published procedure.
Precision Approaches
Runway based
ILS, MLS, PAR
Maximum half scale deflection
DH/DA
Non Precision Approaches
Aerodrome based.
MDA/MDH
Which is higher, MDA or OCH/OCA?
MDA.
Who sets OCH/OCA?
Set by the State
Glideslope is lost during an ILS approach. What happens?
Becomes non-precision approach, must go around.
What must be passed over during a missed approach?
Missed Approach point (MAPt)
Visual Approach
Part of an instrument approach.
Met conditions allow a visual approach and landing to be accomplished.
MUST follow instrument approach profile
Is there need for VMC in a visual approach?
No need for VMC.
Who is responsible for separation during a visual approach?
Separation must be provided by ATC between cleared aircraft and other arr/dep.
Limitations for non-precision
Limitations for Precision
NP - no lower than 1000ft
Precision - not past OM
Arrival Procedure Segments
Arrival
Initial (IAF)
Intermediate (IF)
Final (FAF)
Missed Approach (MAP/MAPt)
Arrival Segment
Permits transition from en-route phase to approach phase
Initial Segment
Aircraft has left en-route structure and entering the instrument procedure
Intermediate Segment
Speed and configuration is adjusted to prepare the aircraft for final approach.
MOC reduces from 300m to 150m.
Final Segment
Alignment and descent for landing are made.
Optimum 5nm, max 10nm
Missed Approach
Must be followed if approach cannot be continued.
Straight in approach
Convergence of 30° or less to the FAT.
NDB approach
5° either side to FAT.
Primary Obstacle Clearance
300/600m, reduces to 0.
What approach navaid is most accurate for track guidance and bearing?
ILS
What approach navaid is most accurate for overhead position?
NDB
What does axis does precision approach use?
Azimuth, glidepath.
Where do STARS commence and end?
At end of route, terminate at IAF
Maximum intercept IAF to IF
90 degrees.
CDFA
Continuous Descent - Depart from IAF at constant descent rate
Terrain Clearance Responsbility
Commander ALWAYS responsible, except during radar vectors.
Calculation of MDA/MDH with FAF and NO FAF.
If FAF exists, 75m (250ft), MOC above highest obstacle.
If no FAF, 90m (300ft)
Calculation of MDH/MDA (Circling)
Obstacle clearance shall not be less for:
CAT A - 120m
MOC 90m
CAT B - 150m
CAT C - 180m
MOC 120m
CAT D - 210m
CAT E - 240m MOC 150m
Optimum Descent Gradient on final approach
5.2%
Max Permissible Descent Gradient (APP)
6.5%. If over, require authority approval.
Track Reversals/ Reciprocated turns (time) for CAT A&B, CAT C&D&E.
CAT A, B - 1 minute
CAT C, D, E - 1m15s
Missed Approach Procedure
Designed to provide protection from obstacles
Missed Approach: Initial Phase
Begins at MAPt, terminates when established on climb.
No turns are permitted.
Missed Approach: Intermediate segment
2.5% Climb Gradient ensures 30m obstacle clearance at all times.
Turns up to 15° are permitted.
Missed Approach: Final Phase
Begins at 50 m obstacle clearance which can be maintained
Turns over 15° are permitted
Aircraft now initiates a new approach, hold/returns en route.
Missed Approach Point (MAPt)
Can be defined from a:
- Navigation Facility
- Fix (including NDB!)
- Specified distance from fix.
May pilots use timing for the MAPt?
Pilots may use timing, unless “timing not authorised for defining MAPt”
What is the purpose of the MAPt
Ensures MOC is not “infringed” during missed approach procedure
RNAV Approaches
Non Precision, based on co-located VOR/DME
RNAV Equipment
Must be approved by state of operator
What is the most important factor with regards to instrument approaches?
Speed
Visual Manoeuvring Circling - VM(C)
Non-precision approach.
Where is VM(C) permitted?
Permitted only in the VM (C) area
Prohibited sector VM(C)
Should there be obstacles within this area, whole area may be precluded.
Why is it circling approach different?
RWY Layout
Met conditions
Final Approach Track (FAT)
Missed Approach Procedure - VM(C)
Pilot will commence a climbing turn, TOWARDS INSTRUMENT RUNWAY, fly overhead aerodrome and CARRY OUT MISSED APPROACH PROCEDURE for INSTRUMENT RUNWAY
Minimum visibility for VM(C) aircraft categories:
CAT A 1
CAT B 1.5
CAT C 2
CAT D 2.5
CAT E 3.5
