Cold soaked fuel frost ( CSFF)

Question 1

Explain CSFF

Answer 1

Frost forms on the upper and lower wing surfaces, due to cold soaked fuel touching the wing surface after long flights with large fuel loads.

Question 2

Identify allowable cold soaked fuel frost area

Answer 2

Painted area on upper wing

Question 3

Presence of painted coal soaked fuel frost area and inclusion of proc in Fcom, allows operator to use it?

Answer 3

Does not constitute operational approval?

Question 4

Frost or ice on lower surface, outboard of measuring stick 4, means?

Answer 4

may also be frost/ice on upper surface.

Question 5

Distance frost extends outboard of measuring stick 4

Answer 5

Be used indication of extent of the frost on upper surface.

Question 6

TO with CSFF on lower wing allowed if ALL following conditions met:

Answer 6

1)Ambient air temp at/above +4deg
2)No precipitation or visible moisture(rain, snow, drizzle, fog less 1mile vis)
3)Tank fuel temp AT/above -16deg
4)All leading edge devices, control surfaces, tab surfaces, winglet surfaces and control surface balance panel cavities must be free snow, ice, frost.

Question 7

(CSFF on lower wing) If all above conditions NOT met?

Answer 7

TO light coatings of frost, up to 3mm on lower wing surface due to Cold fuel is allowed, BUT all LED, all control surfaces, tab surfaces, winglet surfaces and control surface balance panel cavities must be free of snow, ice, frost.

Question 8

Frost on lower surface greater than 3mm?

Answer 8

All snow, ice, frost on wings must be removed with deice/anti-ice procedures.

Question 9

CSFF upper wing surface allowed if?

Answer 9

1)CSFF wing tank upper surface, only within lines defining the permissible CSFF area with NO snow, ice or frost on LED or control surfaces.
2)Ambient air temp at or above +4
3)No precipitation or visible moisture (rain, snow, drizzle, fog less 1mile vis)
4) Fuel Tank fuel temp at or above -16C

Question 10

(CSFF upper wing) Conditions NOT met?

Answer 10

All snow, ice, frost on upper wing surfaces must be removed de/anti-ice.