5.16 Adverse Weather

Question 1

What is the definition of “Icing Conditions?”

Answer 1

Icing conditions exist when OAT (on the ground) or TAT (in flight) is 10°C or below and any of the following exist:

• Visible moisture (clouds, fog with visibility of 1 statute mile (1600m) or less, rain, snow, sleet, ice crystals, etc.) is present; OR

• Ice, snow, slush or standing water is present on the ramps, taxiways, or runways

Question 2

If type II/IV fluid is used for overnight protection, what must be done prior to departure?

Answer 2

All of it must be removed with type I fluid prior to departure

Question 3

Can we takeoff with frost on the lower wing if it is due to cold soaked fuel? If so how thick can it be?

Answer 3

Yes, up to 1/8” thick

Question 4

Can we takeoff with hoarfrost on the upper fuselage?

Answer 4

Yes, provided all ports and vents are clear. Should be able to distinguish features under the hoarfrost such as paint lines, markings, or lettering

Question 5

When engine anti-ice is required and OAT is +3°C or less, what part of the engine needs to be verified to be free of ice?

Answer 5

The first stage of the low pressure compressor

Question 6

Are we allowed to takeoff with snow or ice on the gear strut, gear actuators, gear doors, tires, brakes, or wheels?

Answer 6

No

Question 7

For P&W engines, when can we advance thrust beyond that required for taxi?

Answer 7

When oil temperature is equal to or greater than 50°C

Question 8

When must engine anti-ice be selected ON for all ground operations?

Answer 8

Immediately after engine start and during all ground operations when icing conditions exist or are anticipated except when OAT is BELOW -40°C

Question 9

Can we operate both packs on the ground in icing conditions when only one engine is running?

Answer 9

No

Question 10

Thrust should be limited to what setting when taxiing over significant amounts of standing deicing or anti-icing fluid? Why?

Answer 10

Minimum required. Excessive ingestion of deicing or anti-icing fluid can cause the fluid to build up on the engine compressor blades resulting in compressor stalls and engine surges.

Question 11

When is an engine run up on the ground required? What are the requirements for this run up on the 757?

Answer 11

When engine anti-ice is required and OAT is 3°C or below

“15-50-1” or “fifteen, fifty, one”
-15 mins
-50% N1
-1 second

At intervals no greater than 15 minutes, run the engines up to a minimum of 50% N1 for approximately 1 second duration.

Question 12

What is the exception to the run-up requirements for the 757?

Answer 12

If operationally necessary, the 15 minute run-up time may be exceeded up to, but shall not exceed 30 minutes.
If the time limit of 30 minutes is exceeded, the airplane must be taxied to an area where the engine can be shut down and inspected for ice build up. During this taxi time, engine RPM cannot exceed 40% N1

Question 13

An engine run up is required when engine anti-ice is required and OAT is 3°C or below. What are the requirements for this run up on the 767 with P&W engines?

Answer 13

Same as 757.
“15-50-1”

Question 14

An engine run up is required when engine anti-ice is required and OAT is 3°C or below. What are the requirements for this run up on the 767 with GE engines?

Answer 14

“30-60-30”
Run the engines up to a minimum of 60% N1 for approximately 30 seconds duration at intervals no greater than 30 minutes.

Question 15

What is the requirement for the takeoff procedure when engine anti-ice is required and OAT is 3°C or below?

Answer 15

Accomplish a standing takeoff:

•Hold brakes while in position on the assigned runway until the engines are stabilized at or above 60% N1 before the start of the takeoff roll

Question 16

For the 757, engine anti-ice must be operated in flight under what conditions?

Answer 16

Operate engine A/I ON when in visible moisture and TAT is +10°C or below. No exceptions.

This ensures continuous igniter operation for potential ice crystal icing, and improves engine stall margin

Question 17

For the 767, engine anti-ice must be AUTO or ON in flight under what conditions?

Answer 17

During all flight conditions when icing conditions exist or are anticipated, except during climb and cruise when OAT is below -40°C SAT.

Must be auto or on at all times during descent in icing conditions, including temperatures below -40°C SAT

Question 18

For 767 is there an N1 tolerance for TAI ON in icing conditions?

Answer 18

In flight, maintain N1 at or above the TAI reference bug (45% N1 at or above 10,000, 40% N1 below 10,000’) except as required for landing. 3% tolerance is allowed with autothrottles on.

Question 19

When do we do the fan ice removal procedure on 767s with GE engines, and what is the procedure?

Answer 19

During flight in moderate to severe icing for prolonged periods with N1 settings at or below 70%, or if fan icing is suspected due to high engine vibration.

Increase thrust, one engine at a time, to a minimum of 70% N1 for 10-30 seconds every 10 minutes

Question 20

What should be done regarding wing anti-ice switches when amber ICING light illuminates?

Answer 20

Visually check for indications of airframe icing. If indications of airframe icing exist, turn the WING ANTI-ICE switch to ON

Question 21

For the 757-300 how is maneuver margin affected after the wing anti-ice switch is selected on?

Answer 21

Flaps up maneuver margin to stick shaker is reduced. Add 5 knots to flaps up maneuver margin to ensure full maneuver margin (40° bank capability)

Question 22

What is the Engine Flameout Protection Procedure for 767s with GE engines?

Answer 22

Prior to reducing thrust for descent in visible moisture and TAT less than 10°C, including SAT less than -40°C, nacelle anti-ice switch must be ON.

At or below 22,000’, wing anti-ice selector must be in the ON position

When conditions are no longer present, place nacelle and wing anti-ice selectors/switches to AUTO/OFF

Question 23

When do we do a modified After Landing Procedure?

Answer 23

After prolonged operation in icing conditions with the flaps extended, or when an accumulation of airframe ice is observed, or when landing on a runway contaminated with ice, snow, or slush:
-Do not retract the flaps to less than flaps 20 until the flap areas have been checked to be free of contaminants

Question 24

What 3 weather related runway conditions cause us to not be able to start the takeoff?

Answer 24

-Braking action report of NIL by an air carrier aircraft or airport operator
-Standing water, slush, or wet snow in excess of 1/2” depth
-Dry snow in excess of 4 inches in depth

Question 25

What should be done if Ice Crystal Icing is suspected?

Answer 25

Accomplish Ice Crystal Icing QRH

Question 26

If severe turbulence cannot be avoided, what actions should be taken for aircraft control?

Answer 26

-Descend 4,000’ below optimum altitude
-Reduce speed to severe turbulence penetration speed above 10,000’
-Below 10,000’ slow to 240-250 KIAS
-Turn the autothrottle off
-Engine Start Selectors…CONT

Question 27

What considerations should be made if an approach in severe turbulence must be accomplished?

Answer 27

Delay flap extension as long as possible. The aircraft can withstand higher gust load in the clean configuration.

Question 28

How should a volcanic ash encounter in flight be handled?

Answer 28

QRH section 0