On December 8, 2014, an Embraer EMB-500 airplane (marketed as the Phenom 100), N100EQ, crashed while on approach to runway 14 at Montgomery County Airpark (GAI), Gaithersburg, Maryland. The airplane impacted three houses and the ground about 3/4 mile from the approach end of the runway. The pilot, the two passengers, and the three people in a nearby house died as a result of the accident. The airplane was destroyed by impact forces and postcrash fire.The NTSB determines that the probable cause of this accident was the pilot's conduct of an approach in structural icing conditions without turning on the airplane's wing and horizontal stabilizer deice system, leading to ice accumulation on those surfaces, and without using the appropriate landing performance speeds for the weather conditions and airplane weight, as indicated in the airplane's standard operating procedures, which together resulted in an aerodynamic stall at an altitude at which a recovery was not possible.