Delayed Reaction: Severe Icing and the Minutes That Matter

Ice protection buys time. It doesn't buy permission to stay. When ice builds faster than the airplane can handle, the only fix is to leave, and the longer you wait for a routine clearance, the less airplane you have left to leave with.

The AOPA Air Safety Institute (ASI) re-creates this flight in its video "Accident Case Study: Delayed Reaction," which you can watch below. The summary that follows is ours and is based on the NTSB final report (ERA12FA115), which also gives the official probable cause. Watch the full case study for ASI's own analysis.

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The flight, in short

On December 20, 2011, a 45-year-old instrument-rated private pilot with about 1,400 hours departed Teterboro, New Jersey (TEB) in a Socata TBM 700 on an IFR flight plan to Atlanta (PDK), planning to cruise at FL260. Four passengers were aboard. He had filed his flight plan online at 0700, but the NTSB found no record that he got a weather briefing, and no weather was requested or issued on the ground at Teterboro. An AIRMET for moderate icing from the freezing level to FL200 was issued at 0945. The flight departed about 0950.

On the climb, the controller warned of moderate rime icing from 15,000 to 17,000 feet, with light rime at 14,000, and asked the pilot to report if it got worse. The pilot said they'd let him know and that if they could go straight through, “it’s no problem for us.” He entered the clouds climbing through about 12,800 feet.

At 10:02, level near 16,800 feet, the pilot told the controller “light icing has been present for a little while and a higher altitude would be great.” The airplane's groundspeed was about 101 knots. Seventeen seconds later he reported “a little rattle” and asked to climb as soon as possible. The controller coordinated and cleared him to FL200 about 25 seconds later. Just over a minute after that, the airplane peaked at 17,800 feet, turned sharply left and descended. Passing 17,400 feet the pilot transmitted “and N731CA’s declaring…” and nothing more. The outboard right wing separated in flight and struck the tail. The airplane hit Interstate 287 near Morristown, and all five people aboard were killed.

The NTSB determined the probable cause to be: “The airplane’s encounter with unforecasted severe icing conditions that were characterized by high ice accretion rates and the pilot's failure to use his command authority to depart the icing conditions in an expeditious manner, which resulted in a loss of airplane control.”

Why the delay matters

Pilots in the area that morning reported icing, and at least three crews called it severe. The airplane's handbook warned that it wasn't certificated for severe icing and told pilots who meet it to request priority handling and change altitude or route immediately. The NTSB said the pilot likely either didn't recognize how bad the icing was or was reluctant to use his command authority to get out right away.

• Treat a controller's icing report as a reason to plan your exit before you enter the clouds, not after.
• Watch the airspeed. A steady drop at the same power setting is the airplane telling you how much ice it's carrying.
• Declare early. “Request higher” puts you in line. An emergency puts you first.
• Know your airplane's limits cold. Ice protection certified for known icing is not certified for severe icing.