OMB 4 Performance

Question 1

Climb gradient segments

When are specific departure gradients given?

Answer 1

1st segment- 35 ft to wheels up
* Positive climb
2nd segment - 35 feet to acceleration
* 2.4% GROSS
3rd segment- acceleration to clean
* above 0
4th segment- climb to 1500 AAL
* 1.2 % GROSS

Above 3.3% gross
(2.5% net + 0.8% margin)
0.8 is standard margin for 2 engine aeroplanes

Question 2

What is the lateral clearance on a departure?

When are obstacles within 600 / 900m considered?

Answer 2

90m + 0.125 D
D=distance from end of TODA

Track change under 15º
* Obstacles within 600 m considered

Track change over 150º
* Obstacles within 900m considered

Question 3

Maximum flex reduction on rated thrust?

When is flex not permitted?

Answer 3

25%

Contaminated runway
Dispatch with Landing Gear down

Question 4

What is crosswind limit with Slippery when Wet?

Answer 4

25kt

Question 5

What are the maximum depths of contamination?

water/slush
wet snow
dry snow

Answer 5

13mm water/slush
30mm wet snow
100mm dry snow

Question 6

What is the maximum height of snowbanks after clearing?

Answer 6

0.3
0.6
1.0
1.5
3.0

All 5 metre increments from edge (0.3 at the edge)

Question 7

What table do we check if SNOWTAM states usable runway width is under 40m?

Answer 7

FCOM: MINIMUM CONTROL SPEEDS ON NARROW RUNWAYS

Question 8

Should winds be true or magnetic on EFB?

Where might you need to add a correction?

Answer 8

Magentic

Areas of high variation, e.g. KEF
When using METAR/TAF wind

(ATIS is magnetic)

Question 9

Take Off CG is only an option for A320- what is the limit?

Answer 9

FWD if less than 29% MAC

Question 10

With FLEX figures, ASD performance will be better than shown. How much can it be reduced by?

Answer 10

ASD can be redueced by 3% for every 10ºC between FLEXºC and OAT

( Flexº - OATº ) ÷ 10 × 3

Question 11

How much Headwind and Tailwind is considered by the TO module?

Answer 11

50% Headwind
150% Tailwind

Question 12

What is the default go around gradient?

What is the minimum OEI GA acceleration altitude?

Answer 12

2.5%

Higher of:
* 1500 AAL (VMC or following EOSID)
* GA accel alt (if on chart)
* MSA / TAA / MRVA
* Go around alt

Question 13

What braking is assumed for a dispatch landing calc?

Answer 13

Max manual braking

Margin added as this is unlikely

Question 14

What are the regulatory factors for dispatch RLD with dry / wet / contaminated runways

What are the regulatory factors for LDTA?

Answer 14

1.67 ALD Dry = RLD DRY
1.92 ALD Dry = RLD WET
1.15 ALD Contaminated = RLD CONT

LDTA must have 15% more than required