The U.S. National Transportation Safety Board (NTSB), pointing to a failure to turn on the de-ice system in the December 2014 crash of an Embraer Phenom 100, is recommending that the FAA and industry groups work together to develop a system to alert pilots when ice protection systems should be activated and to develop improved training guidelines for winter weather operations.

The Safety Board, which met June 7 to discuss the crash, determined that the probable cause of the Dec. 8, 2014, Phenom crash in Gaithersburg, Md., was “the pilot’s conduct of an approach in structural icing conditions without turning on the airplane’s wing and horizontal stabilizer de-ice system, leading to ice accumulation on those surfaces.” The NTSB also cited the pilot's failure to use appropriate landing performance speeds for the weather conditions and airplane weight.

“Pilots must rely on checklists and procedures because relying only on memory can have deadly results,’’ said NTSB chairman Christopher Hart. “The pilot’s failure to turn on the de-icing system in an icing situation proved to be disastrous.”

The Phenom, N100EQ, crashed on approach to Runway 14 at Montgomery County Airpark (GAI) in Gaithersburg. Operated by Sage Aviation, the aircraft ran into three houses about three-quarters of a mile from the approach end of the runway, killing the pilot, two passengers and three people in the houses.

Data from the airplane’s cockpit voice and data recorder indicated that 15 minutes after taking off from Horace Williams Airport in Chapel Hill, N.C., the pilot turned on the aircraft’s engine anti-ice and de-ice systems manually for about two minutes, but then manually turned those systems off.

About six minutes later, the pilot received a transmission from the automated weather observing system at GAI that the NTSB said contained “sufficient information to indicate that conditions were conducive to icing during the approach to GAI.” However, the CVDR did not record any further activity involving either ice protection systems, “indicating the pilot did not turn the system back on,” the agency said.

The Phenom 100 Pilot Operating Handbook calls for the pilot to perform a descent checklist before descending through 10,000 feet. For operating in normal icing conditions, the checklist would have included turning on the ice protection systems. But before beginning descent, the pilot set the landing reference speed at 92, indicating that he used performance data for operating with the ice protection systems turned off and for an airplane landing weight less than the aircraft’s actual weight.

“Based on available evidence, the NTSB could not determine why the pilot did not turn on the wing and horizontal stabilizer de-ice system during the approach to GAI,” the Safety Board said, noting the pilot’s instructors reported that use of both ice protection systems was covered during initial and refresher training.

The NTSB, looking at multiple scenarios, said it believes that pilots involved in single-pilot operations would benefit from an automatic alerting system when ice protection systems should be activated. The agency further believes that pilots would benefit from training beyond that required for a check ride.

The Board called on the FAA to work with the General Aviation Manufacturers Association (GAMA) to develop such an automatic alerting system for aircraft that require a type rating and are certified for single-pilot operations and flight in icing conditions. A similar recommendation was issued to GAMA to work with the FAA on the system.

Noting that “significant work” has taken place over the past decade to mitigate icing risks, GAMA president and CEO Pete Bunce said that ongoing work will include a review of the recommendations. Bunce added that efforts to get such new safety technologies into aircraft will be advanced by the Part 23 rewrite and the associated F44 general aviation ASTM standards committee. “The new Part 23 framework lends itself to taking safety actions in a more timely and efficient manner to enable the fielding of new technologies in new and legacy fleet aircraft that will enhance aviation safety, including for icing conditions,” he said.

In addition to the alerting system, the Safety Board also focused on training. The NTSB recommended that NBAA work with members to develop enhanced pilot training guidelines on risk management in winter weather operations and on the adherence to checklists.

“This crash demonstrates the importance of training, proficiency and professionalism for all pilots, professionals and non-professionals alike,” Hart said. “General aviation pilots must take every precaution to prevent accidents. Their calculations must be as precise as possible, and they must follow required procedures applicable to their aircraft. Pilots can never safely skip a checklist or cut a corner, even once—because any flight can turn deadly.”