IRFP-01
Metro Review
b. Decreases lift and increases stall speed: level flight requires
higher angle of attack (AOA)
c.
Effects on thrust production
(1) Propeller-driven aircraft
(a) Ice destroys smooth airflow over propeller surface,
reducing propeller efficiency
(b) In some engine designs, induction system icing limits
available air, therefore reducing available thrust
(2) Jet aircraft: large pieces of ice thrown free by airflow or
deicing systems can be ingested by engines, resulting in
engine damage or failure
d. Other considerations
(1) Pitot and static sources can clog, affecting reliability of
Mach/airspeed indicator, altimeter, and vertical speed
indicator (VSI)
(2) Visibility impaired due to windshield icing
(3) Engine sensors can clog, resulting in improper throttle and
fuel control
(4) Radio range reduced
D. Fog 21.1.1.4.3
1. Common conditions when fog can form: temperature and
dewpoint must be within 3 degrees C/5 degrees F of each other
2. Fog might not form even under conductive conditions
3. Types
a. Radiation (ground fog): forms in saturated air when the
temperature nears dew point and a light breeze is present
(1) Usually dissipates or “burns off” 1 to 4 hours after sunrise
(2) Wind more than 8 kts prevents or dissipates fog
NOTE: Radiation fog is common to NAS Meridian.
b. Advection: forms when moist air moves over surface cool
enough to reduce temperature to near dew point (more
frequent in winter than summer)
(8-97) Original
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