Ops Part A 8.1.1 Flashcards
Except when taking-off and landing, Company aircraft must maintain a separation of:
1000 ft from obstacles or terrain up to 5,000ft AMSL, and 2,000ft from obstacles or terrain higher than 5,000ft AMSL.
In airspace where track is well defined by two separate navaids, separation must be maintained from obstacles and terrain within:
10nm either side of track and 10nm beyond reporting or checkpoints.
Elsewhere separation must be maintained from obstacles and terrain within 20nm either side of track and 20nm beyond reporting or checkpoints.
Safe Altitude applicable to any portion of the flight is to be extracted from the applicable en-route and approach charts as follows:
a. When flying along a published route or track, MOCA, which provides terrain and obstacle clearance within the width of the airway, may be used.
b. When only an MEA is published for a route, it may be used.
c. When flying off route, Grid MORA, which provides clearance within the area defined by latitude and longitude lines, may be used.
d. When using charts to derive MOCA, MEA or Grid MORA it is vitally important that the Commander is at all times satisfied with the accuracy of his navigation in relation to the track being followed.
e. Minimum altitudes depicted on STAR charts may be used.
f. The 25nm MSAs shown on approach charts provide 1,000 ft separation but do not guarantee navaid reception. Nevertheless they can provide useful information in the vicinity of the airfield and are authorised for use during approach to or departure from an airfield provided that:
i. The navigational beacon on which the MSA is based is tuned, identified and continuous reception is maintained. Alternatively, provided NAV ACCURACY is HIGH, the specified MSA reference point may be displayed on the PROG page or as a fix on the Navigation Display.
ii. The Commander is satisfied that the aircraft is within 25nm of the specified aid.
iii. For RNAV/RNP/GPS approaches, the Commander is satisfied that the aircraft is within 25nm of the specified MSA reference point.
g. Lower separation standards are authorised under the following conditions:
i. When carrying out a published and approved approach procedure.
ii. When IFR under positive radar control.
iii. When operating on an IFR plan but in VMC and at least 1,000ft on top, or in sight of land or water.
iv. When VFR.
The purpose of the TAA is to provide a transition from the enroute airway structure to the terminal environment for arriving aircraft equipped with FMS and/or GNSS navigation equipment. The underlying instrument approach is a RNAV procedure. The TAA will not be found on all RNAV approaches, particularly in areas with high traffic density. When a TAA is published, it replaces the:
MSA for that approach procedure.
Straight-In Area
The area is defined by a:
a semi-circle with a radius of 25nm (ICAO) / 30nm (FAA) centred on and extending outward from the IF/IAF. The altitude shown within the Straight-in area provides minimum IFR obstacle clearance of 300m or 1,000ft.
Base Area
The Left and Right Base areas are bounded by the:
Straight-In TAA and the extension of the intermediate segment course. The Base areas are defined by a radius of 25nm (ICAO) / 30nm (FAA) centered on the IAF on either side of the common IF/IAF. The altitude shown within the Base area provides minimum IFR obstacle clearance of 300m or 1,000ft.
RADAR CONTROL
When under radar control within 25nm of the departure or arrival airfield, a separation of
1,000ft from obstacles and terrain within 5nm either side of track or intended track must be maintained. At all times when under radar control, the position of the aircraft must be monitored by reference to other aids. Radar control does not relieve a Commander of his responsibility to ensure adequate terrain and obstacle clearance. Crews must be ready to assume responsibility immediately should there be loss of communication.
High ground in some parts of the Company’s AOC region makes terrain clearance a significant consideration in the event of an en-route engine or pressurisation failure. The strategy adopted by the crew, following an engine failure, will depend on the nature of the surrounding terrain.
If obstacle clearance is a problem:
Obstacle Strategy is to be followed, otherwise Standard Strategy is to be used. Both strategies are detailed in FCOM/PER-OEI-GEN-05 Strategy.
Initial stabilising altitude is significantly different depending on the:
strategy used to descend following an en-route engine failure, with Obstacle Strategy resulting in a higher stabilising altitude due to the lower cruise speed.
Ground distance covered will also vary depending on the:
strategy used, with Obstacle Strategy giving a longer driftdown distance. Variations in start altitude, weight, temperature deviation and wind will also affect both the distance covered in the descent and the stabilising height, as will the use of Engine or Total anti-icing.
MCDU Progress page can give useful information regarding:
distance to en route alternates and Engine Out Maximum Recommended Altitude (EO MAX REC ALT).
As a quick reference, single engine fuel burn and time to an en-route alternate can be obtained from:
QRH/PER-L (A320/A321) or QRH/PER-N (A330) ‘In Cruise Quick Check Long Range’.
In case of a pressurisation failure, it is vitally important that the crew is aware of and level off from an:
emergency descent, above the prevailing safe altitude. QNH is to be set on both altimeters.
If wave development is forecast or known to be present:
a. Do not attempt to penetrate or approach rotor clouds or likely rotor zones adjacent to mountain ranges.
b. An in-flight clearance of at least 5,000ft is necessary above mountains which are up to 5,000ft in height above the surrounding terrain; for higher mountains the clearance should be at least equal to their height above the terrain; this should enable the worst of the lower altitude hazards to be avoided.
c. Choose cruising altitudes well away from the base of layers of marked instability in the atmosphere where severe turbulence is most likely to occur (present information suggests that there may be more than one unstable layer, a margin of 5,000ft on either side of the tropopause is advisable).
d. When flying in an area in which mountain wave conditions are suspected, always be prepared for turbulence, even in clear air, and take precautions accordingly.
For flights within 20nm of terrain having a maximum elevation exceeding 2,000ft, the safe altitude is to be increased by at least the following increments to counteract wind effect:
TERRAIN ELEVATION WIND SPEED
0 – 30kt 31 – 50kt 51 – 70kt over 70kt
2,000 – 8,000ft 500ft 1,000ft 1,500ft 2,000ft
Above 8,000ft 1,000ft 1,500ft 2,000ft 2,500ft
When temperature at the aerodrome is below the ISA value, it is the responsibility of the Commander to consider the effect of temperature on the:
minimum and reference altitudes. If corrections are to be made, the guidelines below shall be used and all corrections shall be based upon height Above Aerodrome Level (“AD Elev” on Navblue charts).
Corrections to MSA
Corrections to MSA shall be made when the ambient surface temperature is lower than ISA -15°C, using the table below.
SURFACE TEMPERATURE CORRECTION
ISA -16°C to ISA -24°C Not less than +10%
ISA -25°C to ISA -34°C Not less than +15%
ISA -35°C to ISA -45°C Not less than +20%
< ISA -45°C Not less than +25%
For the purposes of this paragraph, MSA should be considered to include the lowest safe altitude for the flight phase, i.e. 25nm MSA, MRA, Grid MORA, MEA, MOCA, etc.
Corrections to Altitudes Below MSA
ICAO recommends that, when under radar control, ATC should apply cold weather corrections.
ATC consider that once a clearance has been accepted, it will be complied with. Therefore, if an aircraft is cleared to an altitude which the Commander finds unacceptable due to low temperature, a higher altitude should be requested.
Corrections for DA(H), MDA(H), IF/IAF/FAF altitudes, missed approach altitude, circling minima and glide slope check altitudes, which are at or below MSA, shall be made according to the table below when the reported aerodrome temperature is 0° C (or chart temperature limit, if applicable) or below.
Height AAL (ft)
200 300 400 500 600 700 800 900 1000 1500 2000 3000 4000 5000
Aerodrome Temperature (C)
0 20 20 30 30 40 40 50 50 60 90 120 170 230 280
- 10 20 30 40 50 60 70 80 90 100 150 200 290 390 490
- 20 30 50 60 70 90 100 120 130 140 210 280 420 570 710
- 30 40 60 80 100 120 140 150 170 190 280 380 570 760 950
- 40 50 80 100 120 150 170 190 220 240 360 480 720 970 1210
- 50 60 90 120 150 180 210 240 270 300 450 590 890 1190 1500
