11-203V1 Wx For Aircrew

Question 1

What are the 4 types of icing?

Answer 1

Clear, Rime, Mixed, Frost
- Frost is a form of icing but is not forecasted

Question 2

Clear icing:

Answer 2

The most serious form of icing.
- Glossy like and ADHERES firmly to aircraft
- High water content and large droplets
- Difficult to remove

Question 3

Rime icing:

Answer 3

Rime icing is milky/Opaque, with a rough surface.
- Instant freezing of small supercooled water droplets
- Less severe than clear icing, easy to remove

Question 4

Mixed icing:

Answer 4

Mixed icing rapidly forms when liquid drops are intermingled with snow/ice.
- Very rough accumulation and can be embedded in clear icing

Question 5

Frost icing:

Answer 5

Still icing but is it not forecasted like the other 3
- Thin layer of ice
- Forms on exposed surfaces of the aircraft and can affect lift/drag
- Remove all frost before departure

Question 6

Windshear Changes to Airspeed and VVI

Answer 6

Airspeed changes greater than 15 knots and VVI changes greater than 500 FPM

Deviation in magnitude and/or direction of winds in a vector wind field. Severe windshear causes airspeed changes greater than 15 knots or VVI changes greater than 500 fpm

• Particularly hazardous within 2000 AGL (but can occur at any altitude)