Why Better Icing Detection on Aircraft Is So Important

Ice accumulation on airplanes is one of the major causes of weather-related accidents. The “classic” icing certification envelopes – from the Federal Aviation Regulation Sec. 25.1419 on ice protection – cover at most only 99% of the icing conditions encountered during research flights conducted over 50 years ago. Outside of these conditions, ice can accumulate rapidly and cause loss of control in minutes.

Ice ingestion by turbines can cause severe power loss. This is what happened when the AirBridge Cargo 747-8F plane experienced core engine icing that caused malfunction and damage to three engines on a flight from Chengdu, China to Hong King in July 2013 (fortunately that plane landed safely at its destination).

To mitigate against these kinds of problems, the Federal Aviation Administration (FAA) added Supercooled Large Drop (SLD) Icing Conditions to 14 CFR 25 as Sec. 25.1420 in 2014. This added urgency for aircraft manufacturers to further safeguard their planes against a broader range of icing conditions.

sld-chart-1
Credit: After Martins et al. (2005).

 

 

There’s good news on the automatic icing detection front.

Technologies originally developed for space applications can now be used to detect icing and even determine when an airplane is flying outside of the classic icing certification envelopes. These new technologies, from Intelligent Vision Systems (IVS), builds upon the work of the University of Michigan College of Engineering’s Department of Climate and Space Sciences and Engineering. The technologies use only non-intrusive sensors to detect icing and measure cloud liquid water content.