OMB PERF

Question 1

What is maximum allowed reduction of thrust?

Answer 1

35%

Question 2

When is a Flex takeoff prohibited?

Answer 2

• Contaminated
• Dispatch with L/G extended
• Reported Windshear

Question 3

Why do we use Flex/reduced takeoff thrust?

Answer 3

It lowers turbine operating temperatures and increases hot section life.

Question 4

What additional performance margins are provided by FLEX temps in accelerate stop and accelerate go conditions?

Answer 4

1. TAS is lower at actual temp

2. Thrust delivered is higher at the ambient temp

Question 5

What is a ‘significant portion’ of runway with regards to contamination?

Answer 5

25% of 1/3 of runway (1/12th runway surface)

Question 6

What are two forms of contaminants?

Answer 6

• Fluid contaminants not considered thin

- Hard contaminants

Question 7

What are types of Fluid contaminants?

Answer 7

• standing water
• slush
• dry snow
• wet snow

Question 8

What are hard contaminants?

Answer 8

• compacted snow
• ice
• Wet ice

Question 9

What contaminants should you not take off with?

Answer 9

• > 13mm standing water or slush
• > 30mm wet snow
• > 100mm dry snow
• wet ice
• water on top of compacted snow
• dry snow over ice
• wet snow over ice

Question 10

When is FWD C.g selected?

Answer 10

Less than 29% MAC

Question 11

When is dispatch from narrow runway not allowed?

Answer 11

• NWS inop
• one brake or more inop
  Auto land is not permitted

Question 12

How much is the ASD reduced by assuming Flex 50, 10 degs OAT & 3000m runway?

Answer 12

3% per 10 degs difference
Therefore, 0.03x4x3000=360m
3000m-360m=2640m

Question 13

When do you use RWYCC and when do you use contaminant type and depth?

Answer 13

Takeoff and dispatch landing- comtam type and depth

In-flight landing- RWYCC

Question 14

Do you get credit for reversers in DISPATCH computation?

Answer 14

Dry- no
Wet- no
Contaminated- yes (if you need to remove it, select reversers inop as MEL)