FAA Flight Instructor Airplane (FIA)Weather and Weather ServicesMedium
A pilot receives a weather briefing that includes a forecast for 'moderate rime icing in clouds between 5,000 feet and 10,000 feet MSL.' What is the most significant hazard associated with rime icing?
- ABrittleness and easy shedding from the airframe, posing minimal threat to flight controls.
- BRapid accumulation that can drastically alter the airfoil shape and increase drag.
- CFormation primarily on leading edges, making it difficult to detect visually during flight.
- DIts transparent nature, which can conceal other forms of ice accumulation.
Show answer & explanationAnswer & explanation
Correct answer: B. Rapid accumulation that can drastically alter the airfoil shape and increase drag.
Rime icing forms when small supercooled water droplets freeze on impact, creating a rough, opaque, and brittle ice. While it is brittle, its rapid and rough accumulation significantly disrupts airflow, increases drag, and reduces lift, making it a serious hazard.
Why the other options are wrong
- A. While brittle, it does not easily shed and its accumulation is a significant hazard, not minimal.
- C. Rime ice is opaque and forms on leading edges, making it visually distinct and detectable.
- D. Rime ice is opaque and white, not transparent like clear ice.
Rime Ice
Opaque, white, and rough ice formed by the rapid freezing of small supercooled water droplets on impact with an aircraft surface.
- Forms from small supercooled water droplets.
- Appears opaque, white, and rough.
- Rapidly alters airfoil shape, increasing drag and decreasing lift.
Memory trick: Clear and Rime, don't climb or dive, or you'll be a Glaze in time!