History of Flight
On June 5, 2008, about 1300 central daylight time, an Eclipse Aviation Corporation EA500 airplane, registration N612KB, sustained no damage when its flight crew encountered a loss of thrust control with both engines at maximum power during an approach to land on runway 22L at Chicago Midway International Airport (MDW), Chicago, Illinois. A go-around was performed, and the crew shut down the right engine on base leg. The left engine went to flight idle, and the crew encountered a total loss of thrust and continued loss of thrust control. The crew declared an emergency and performed a forced landing on runway 22R. The airplane was operating under 14 CFR Part 91 on an activated IFR flight plan. The two airline transport rated pilots and two passengers were uninjured. The business flight originated from Cleveland-Hopkins International Airport, Cleveland, Ohio, about 1145.
The left-seated pilot, who was the flying pilot, reported that as the airplane crossed the runway 22L threshold during the initial approach, he and the non-flying pilot encountered a 10 to 15-knot wind shear. The airplane developed a high sink rate that he arrested by applying power. After touchdown at about 83 knots and light braking, he noted that the airplane was rapidly accelerating through 100 knots and that the engines were at maximum power. Both pilots observed on the crew alerting system (CAS) display messages "L ENG CONTROL FAIL" and "R ENG CONTROL FAIL" and the Automatic Power Reserve armed light illuminated as the airplane climbed out during the go-around. The flying pilot stated that although he had lowered the landing gear and brought the flaps from landing to takeoff position to remain below 200 knots, a shallow climb was necessary to avoid exceeding 200 knots.
The pilots declared an emergency, and air traffic control cleared them to land on any runway. After referencing the quick reference handbook emergency procedures section "2.5 Engine Control Fail," they elected to shut down the right engine. As they maneuvered to land, they received a stall warning and the airspeed was decreasing. The left engine was at idle power and would not respond to throttle movements. The airplane landed and stopped on the runway. The two main landing gear tires were found flat after the airplane came to rest.
Personnel Information
The flying pilot held an FAA airline transport pilot certificate with airplane single-engine and multiengine land ratings, commercial privileges for single-engine sea, a flight engineer certificate with turbojet rating, and a first class medical certificate. He reported 21,500 hours total flight time with 300 hours in the EA500. He held type ratings in Boeing 727 and 737, Convair 240/340/440, McDonnell Douglas DC-3 and DC-9, Eclipse EA500, Lockheed L-382 and L-1329, and Saberliner N-265 airplanes.
The non-flying pilot held an FAA airline transport pilot certificate with multiengine land rating, commercial privileges for rotorcraft and instrument helicopter, private privileges for airplane single engine, and a first class medical certificate. He reported about 2,400 hours total flight time with 89 hours in the EA500.
Aircraft Information
N612KB, an Eclipse EA500, serial number 000026, was a five-place, pressurized, retractable tricycle landing gear, twin-engine monoplane of aluminum construction. It was powered by two Pratt & Whitney Canada PW610F-A turbo-fan engines, each producing 950 pounds of takeoff thrust. Maximum gross weight was 5,800 pounds. The airplane was last inspected on May 31, 2008, under a continuous airworthiness program, and had accumulated 238.9 flight hours at the time of the incident.
The airplane's flight manual described that each engine is controlled by a dual-channel Full Authority Digital Engine Control (FADEC) unit. Each FADEC has two control channels, one for each engine. The Automatic Power Reserve (APR) feature automatically increases thrust on the operating engine in the event of an engine failure during takeoff.
Meteorological Information
At 1151, MDW weather: wind 190 degrees at 13 knots gusting to 22 knots; visibility 10 statute miles; scattered clouds at 2,900 feet; temperature 28°C; dew point 23°C; altimeter 29.72 inHg.
At 1251, MDW weather: wind 200 degrees at 18 knots gusting to 26 knots; visibility 10 statute miles; scattered clouds at 2,900 feet; temperature 29°C; dew point 22°C; altimeter 29.71 inHg.
Tests and Research
Diagnostic storage unit (DSU) data showed both engines' FADECs encountered a fault signal from the throttle controls around the time of the pilot's reported windshear application. The left engine went to flight idle when the right engine was shut down with the thrust lever at idle. The right engine FADEC was reset by the shutdown. With the right engine thrust lever at idle (below 65 degrees), the left engine was brought to idle per fault logic.
Tests with the airplane's throttle quadrant assembly (TQA) revealed that when moderate forward pressure was applied at the maximum power stop, engine control fail messages appeared on the CAS display. This was repeatable and could be cleared by cycling FADEC power. The incident TQA produced a signal exceeding manufacturer's specified parameters when 44.5 pounds of forward load was applied (38.5 pounds when uncovered). A new TQA also exceeded parameters at 40 pounds. The FADEC fault logic was designed to "latch" the last good value when the upper parameter limit was exceeded, and allowed an engine with a loss of FADEC to use the other engine's throttle setting when that throttle was greater than 65 degrees; otherwise, thrust went to idle.
Additional Information
The National Transportation Safety Board recommended to the FAA an immediate inspection of Eclipse 500 throttle quadrants to prevent engine control failure from pushing throttles against the stops, and development of an emergency procedure for dual engine control failure. The airplane manufacturer issued Alert Service Bulletin 500-76-001, Rev A, dated July 1, 2008, for testing throttle quadrant assemblies.
The incident flying pilot noted that the Cessna Citation Mustang has a "FADEC RESET" switch, which would have been beneficial in this situation, as resetting required pulling and resetting eight circuit breakers.