Three people in a jet and three on the ground died during a fiery crash in 2014 that the National Transportation Safety Board (NTSB) says was caused by the pilot’s failure to turn on de-icing equipment.

The jet crashed into a neighborhood in Gaithersburg, Maryland on Dec. 8 after an accumulation of ice on the wings sent it into an aerodynamic stall. In addition to the fatalities, three houses were damaged by the ensuing fire.

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

Snowing outside

The NTSB’s investigation found the pilot did not use the wing and horizontal stabilizer de-icing system on the Embraer EMB-500 Phenom during the approach to Montgomery County Airpark, despite conditions reported by the automated weather observing system, his earlier use of the de-icing system during the flight and, according to the cockpit voice and data recorder, the observation of a passenger that it was snowing outside.

By not taking possible icing into consideration, the pilot set approach and landing speeds that were too slow for conditions, leading to an aerodynamic stall at an altitude at which a recovery was not possible. The airplane crashed less than a mile from the runway.

Pilot skipped checklist items

Investigators, using information gleaned from the flight recorder, also found evidence that the pilot skipped certain checklist items and procedures before takeoff.

The board issued one recommendation each to the Federal Aviation Administration and the General Aviation Manufacturer’s Association that they develop a system that can automatically alert pilots when ice protection systems should be turned on in certain airplanes. The NTSB also recommended to the National Business Aviation Association that it develop enhanced pilot training guidelines for flying in winter weather conditions, including the use of ice protection and adherence to checklists.

A synopsis of the investigation, as well as findings, recommendations and the finding of probable cause can be found here: www.ntsb.gov/news/events/Pages/2016_gaithersburg_BMG.aspx