Accident Embraer EMB-500 Phenom 100 N100EQ,

ASN Wikibase Occurrence # 320395

Date:	Monday 8 December 2014
Time:	10:41
Type:	Embraer EMB-500 Phenom 100
Owner/operator:	Sage Aviation
Registration:	N100EQ
MSN:	50000082
Year of manufacture:	2009
Engine model:	Pratt & Whitney Canada PW617F-E
Fatalities:	Fatalities: 3 / Occupants: 3
Other fatalities:	3
Aircraft damage:	Destroyed
Category:	Accident
Location:	1 km NW of Gaithersburg-Montgomery County Airport, MD (GAI) - United States of America
Phase:	Approach
Nature:	Private
Departure airport:	Chapel Hill-Horace Williams Airport, NC (KIGX)
Destination airport:	Gaithersburg-Montgomery County Airport, MD (GAI/KGAI)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
An Embraer EMB-500 Phenom 100 corporate jet was destroyed when it crashed in a residential area at Gaithersburg, Maryland. The three occupants of the plane and three people inside a house were killed.
The takeoff about 09:45 from Chapel Hill-Horace Williams Airport, North Carolina, and the cruise portion of the flight were uneventful.
Before beginning the descent, the pilot set the landing reference (Vref) speed at 92 knots, indicating that he used performance data for operation with the wing and horizontal stabilizer deice system turned off and an airplane landing weight less than the airplane's actual weight. Using the appropriate Normal Icing Conditions checklist and accurate airplane weight, the pilot should have flown the approach at 126 knots (a Vref of 121 knots +5 knots) to account for the icing conditions.
The pilot failed to use the wing and horizontal stabilizer deice system during the approach, even after acknowledging the right seat passenger's observation that it was snowing when the airplane was about 2.8 nautical miles from the destination of Gaithersburg-Montgomery County Airport. The airplane was on approach to runway 14 when the ice accumulation caused an aerodynamic stall at a higher airspeed than would occur without ice accumulation. Because the deice system was not activated by the pilot before landing, the band indications (low speed awareness) on the airspeed display did not appropriately indicate the stall warning speed. Once the airplane stalled, its altitude was too low to recover.
The airplane impacted three houses in the 19700 block of Drop Forge Lane about 3/4 mile from the approach end of the runway.

PROBABLE CAUSE: "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 airplanes standard operating procedures, which together resulted in an aerodynamic stall at an altitude at which a recovery was not possible."

METAR:

14:55 UTC / 09:55 local time:
KGAI 081455Z 04005KT 10SM OVC028 M01/M09 A3062 RMK AO1 52003

15:15 UTC / 10:15 local time:
KGAI 081515Z 05005KT 10SM FEW023 OVC030 M01/M08 A3061 RMK AO1

15:35 UTC / 10:35 local time:
KGAI 081535Z 04006KT 10SM FEW021 OVC032 M01/M08 A3061 RMK AO1
Wind: 040 degrees at 6 knots; Visibility: 10+ miles; Clouds: few at 2100 feet, overcast cloud deck at 3200 feet AGL; Temperature: -1°C; Dewpoint: -8°C; Pressure: 1036.7 mb

15:55 UTC / 10:55 local time:
KGAI 081555Z 05005KT 10SM OVC032 M01/M08 A3060 RMK AO1
Wind: 050 degrees at 5 knots; Visibility: 10+ miles; Clouds: overcast cloud deck at 3200 feet AGL; Temperature: -1°C; Dewpoint: -8°C; Pressure: 1036.3 mb

Accident investigation: