HOLD OVER TIME Flashcards
HOLD OVER TIME (HOT)
DEFINITION
“HOT is the span during which anti-icing fluid will prevent ice,frost or snow to form or accumulate” - GREEN NAVTECH SUPP MET 5.1
WHEN THE (HOT) STARTS?
“It starts at the beginning of the final anti-icing treatment” - GREEN NAVTECH SUPP MET 5.1
“Note: The start of the holdover time is from the beginning of the anti-icing treatment. For each type of weather condition, OAT and fluid type, a holdover time range is shown in which the upper limit represents light conditions and the lower one moderate conditions.” - OMA 8.2.4.3
WHAT ARE THE CRITICAL SURFACES THAT SHOULD BE FREE OF ICE?
“Note: Critical surfaces include: wings, flight controls, engine inlets, fuselage surfaces in front of engines, or other areas defined in the FCOM of the relevant aircraft.” - OMA - 8.2.4
What is the only acceptable criteria to use the HIGHER time in the HOT table cell?
Note: The only acceptable decision making criterion for takeoff without a pre-takeoff contamination inspection, is the shorter time within the applicable HOT table cell.” - OMA 8.2.4.3
When to perform a pre-takeoff contamination inspection (internal)
“Transport Canada’s interpretation of the phrase “inspected immediately prior to take-off”, in the ground icing context, is that the inspection must be conducted within five minutes prior to beginning the take-off roll, except for Type I fluids” - TP 14052E - 11.1.7 Holdover Time Exceeded
- EXAMPLE:*
- Fluid Type SAE Type IV (Generic), 75/25 mix*
- Weather −1°C, Snow*
- Holdover Time 0:30 to 0:55*
- <30 minutes No inspection required (consider other factors)*
- 30-55 minutes Pre Takeoff Contamination Inspection (internal) required*
- >55 minutes Pre Takeoff Contamination Check (external) required*
HOW to perform a pre-takeoff contamination inspection (internal)
FIVE MINUTES before takeoff, one pilot goes to the cabin on the upper wing an check if there is any evidence of ice, snow or frost.
its allowed by the OMA
HOW to determine the applicable HOT
- CHECK THE LATEST METAR
- Determine the Intensity using the table “ Visibility and Snowfall Intensity” on chart binder
- Enter in the table of the AVAILABLE FUID
WHAT IS LOUT ?
Lowest Operational Use Temperature (LOUT)
What is the MAIN concept about Cold Weather ?
CLEAN WING
What kind of ice is acceptable on the upper fuselage part of aircraft?
“Thin hoarfrost is acceptable on the upper surface of the fuselage”. - PRO-NOR-SUP-ADVWXR P 4/16
What is accepted to be on the underside of the wing tank areas?
“On the underside of the wing tank areas, a maximum layer of 3 mm (0.125 in) of frost is acceptable” - PRO-NOR-SUP-ADVWXR P 4/16
What is HOAR FROST ?
“Thin hoarfrost is typically a white crystalline deposit which usually develops uniformly on exposed surfaces on cold and cloudless nights. It is so thin that surface features (lines or markings) can be distinguished beneath it.”- LIM-ICE_RAIN P 1/2
What is SEVERE ICE ACCRETION
Ice accretion is considered severe when the ice accumulation on the airframe reaches approximately 5 mm (0.2 in) thick or more - LIM-ICE_RAIN P 1/2
DEFINITION of ICING CONDITIONS
- ” Icing conditions exist when the OAT (on ground or after takeoff) or the TAT (in flight) is at or below 10 °C and visible moisture in any form is present (such as clouds, fog with visibility of 1 sm (1 600 m) or less, rain, snow, sleet or ice crystals).*
- ‐ Icing conditions also exist when the OAT on the ground and for takeoff is at or below 10 °C and operating on ramps, taxiways or runways where surface snow, standing water or slush may be ingested by the engines, or freeze on engines, nacelles or engine sensor probes”- LIM-ICE_RAIN P 1/2*
MAX TAXI SPEED WHEN CONTAMINATED
10KTS OR LOWER
ALTITUDE CORRECTIONS
WHEN TO APPLY?
FLUID COLORS
TYPE I
FLUID COLORS
TYPE II
FLUID COLORS
TYPE III
FLUID COLORS
TYPE IV
