Welcome Guest. Sign in or Signup

2 Answers

Freezing Levels

Asked by: 4419 views Instrument Rating

Here's a questions I've often pondered about... I understand that the standard atmospheric lapse temperature rate is 2*c per 1,000ft. Now, If the freezing levels are forecasted to be at an altitude where clouds are at, I understand that acft structural icing can/will/possibly occur... Now, my question is, at which temperature will a cloud at a certain temperature not cause alarm for icing...?? If It's -2*f at 8,000ft and clouds are at present... will icing mostly likley occur? Hope this is clear enough

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

2 Answers



  1. Tijmen de Boer on Oct 29, 2013

    Depends on several things, but most importend are: Layered or convective cloud and how much water the clouds contain and T range.
    Simplified:
    Thick Layered clouds: mod/sev icing up to -15 degr C, colder light ice
    Thin layered cloud: light/moderate icing up to -10 degr C. Colder only light.
    Convective cloud (CB): mod/sev icing up to -23 degr C, Up to -40 only light ice.

    Tijmen
    Senior forecaster NL

    +2 Votes Thumb up 2 Votes Thumb down 0 Votes



  2. Lion on Oct 30, 2013

    If there is a VISIBLE moisture and the temperature at or below 32F, there will always be a chance of icing (depending on the amount of moisture and the OAT).

    Tijmen provided nice and simplified way as how to determine the severity of the icing using the amount of moisture (as he represented by the the thickness of the clouds) and the OAT at your altitude.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.