2014 – Dec 8, Sage Aviation crash, on AP approach, into houses, fire, Gaithersburg MD– 6

–6 NTSB. Aerodynamic Stall and Loss of Control During Approach…Gaithersburg…Dec 8, 2014.

Narrative Information

NTSB Abstract: “This report discusses the December 8, 2014, accident in which an Embraer EMB-500 airplane (marketed as the Phenom 100), N100EQ, registered to and operated by Sage Aviation LLC, crashed while on approach to runway 14 at Montgomery County Airpark, Gaithersburg, Maryland. The airplane impacted three houses and the ground about 3/4 mile from the approach end of the runway. A postcrash fire involving the airplane and one of the three houses, which contained three occupants, ensued. The pilot, the two passengers, and the three people in the house died as a result of the accident. The airplane was destroyed by impact forces and postcrash fire. Safety issues relate to the need for a system that provides automatic alerting when ice protection systems should be activated on turbofan airplanes that require a type rating and are certified for single-pilot operations and flight in icing conditions, such as the EMB-500; and the need for training for pilots of these airplanes beyond what is required to pass a check ride. Safety recommendations are addressed to the Federal Aviation Administration, the General Aviation Manufacturers Association, and the National Business Aviation Association.

Executive Summary

“On December 8, 2014, about 1041 eastern standard time, an Embraer EMB-500 airplane
(marketed as the Phenom 100), N100EQ, registered to and operated by Sage Aviation LLC,
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. A postcrash fire involving the airplane and one of the three houses, which
contained three occupants, ensued. The pilot, the two passengers, and the three people in the
house died as a result of the accident. The airplane was destroyed by impact forces and postcrash
fire. The flight was operating on an instrument flight rules flight plan under the provisions of
14 Code of Federal Regulations (CFR) Part 91. Visual meteorological conditions prevailed at the
time of the accident.

“Data from the airplane’s cockpit voice and data recorder (CVDR) indicated that the
takeoff about 0945 from Horace Williams Airport, Chapel Hill, North Carolina, and the cruise
portion of the flight were uneventful. CVDR data showed that about 15 minutes after takeoff,
the passenger in the right cockpit seat made a statement that the airplane was ‘in the clouds.’ A
few seconds later, the airplane’s engine anti-ice system and the wing and horizontal stabilizer
deice system were manually activated for about 2 minutes before they were manually turned off.
About 6 minutes later, a recording from the automated weather observing system (AWOS) at
GAI began transmitting over the pilot’s audio channel, containing sufficient information to
indicate that conditions were conducive to icing during the approach to GAI. The CVDR
recorded no activity or faults during the rest of the flight for either ice protection system,
indicating that the pilot did not turn the systems back on.

“Before the airplane descended through 10,000 ft, in keeping with procedures in the EMB-500 Pilot Operating Handbook, the pilot was expected to perform the Descent checklist
items in the Quick Reference Handbook (QRH), which the pilot should have had available in the
airplane during the flight. Based on the AWOS-reported weather conditions, the pilot should
have performed the Descent checklist items that appeared in the Normal Icing Conditions
checklist, which included turning on the engine anti-ice and wing and horizontal stabilizer deice systems. That action, in turn, would require the pilot to use landing distance performance data
that take into account the deice system’s activation.

“CVDR data show that, 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.4 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 NTSB’s investigation found that the pilot’s failure 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 GAI) led to
ice accumulation, an aerodynamic stall at a higher airspeed than would occur without ice
accumulation, and the occurrence of the stall before the aural stall warning sounded or the stick
pusher activated. 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. The NTSB’s aircraft performance study found that there would have been
sufficient warning of an aerodynamic stall had the wing and horizontal stabilizer deice system
been used during the approach. Once the airplane stalled, its altitude was too low to recover.

“Based on available evidence, the NTSB could not determine why the pilot did not turn on
the wing and horizontal stabilizer deice system during the approach to GAI. The pilot’s
EMB-500 instructors reported that use of both ice protection systems was covered during initial
and recurrent training, and the pilot turned on both systems when he encountered conditions
conducive to icing shortly after taking off on the accident flight. This information suggests that
the pilot was informed about the criteria for using these systems….

“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.”

Sources

National Transportation Safety Board. Aircraft Accident Report. Aerodynamic Stall and Loss of Control During Approach, Embraer EMB-500, N100ERQ, Gaithersburg, Maryland, December 8, 2014 (NTSB/AAR-16/01). Washington, DC: NTSB, Adopted June 7, 2016. 71pages. Accessed 3-24-2023 at: https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR1601.pdf