HISTORY OF FLIGHTOn August 21, 2015, about 1420 eastern daylight time, an Eclipse Aviation Corporation EA500, N120EA, sustained substantial damage during a runway overrun while landing at Danbury Municipal Airport (DXR), Danbury, Connecticut. The airline transport pilot and two passengers sustained minor injuries. Day visual meteorological conditions prevailed and an instrument flight rules flight plan had been filed for the personal flight. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. The flight originated from Wittman Regional Airport (OSH), Oshkosh, Wisconsin, about 1220.
According to the pilot, the approach to runway 26 "required a steeper than normal approach," because of trees near the runway. The airplane touched down near the displaced threshold and he applied the brakes to deceleratee; however, the "first pedal push was soft," which was "not unusual." Then, he continued "pumping the brakes" and considered a go-around; however, the remaining runway was too short. The pilot continued to "pump" the brakes, about six times; however, he did not think the brakes were operating. The airplane continued off the end of the runway, impacted a berm, and came to rest upright approximately 200 feet beyond the end of the runway.
According to an air traffic controller who witnessed the accident, the airplane touched down approximately 100 feet past the "D" taxiway intersection with the runway, which would have resulted in about 2,800 feet of runway remaining.
During the accident sequence, the right main landing gear punctured the underside of the right wing, which resulted in substantial damage. In addition, the nose landing gear separated from the airplane. PERSONNEL INFORMATIONAccording to the pilot, he held an airline transport pilot certificate with a rating for airplane multiengine land and a private pilot certificate with ratings for airplane single-engine land and sea. In addition, he held a type rating for the EA-500S, which included the accident airplane model. The pilot was issued an FAA third-class medical certificate on March 27, 2015. He reported 7,846 hours of total flight experience, of which 1,111 hours were in the same make and model as the accident airplane, and 3.7 hours were accumulated during the 30 days that preceded the accident. In an interview, the pilot stated that the six previous landings he performed with the airplane were on runways that were over 6,000 feet long. AIRCRAFT INFORMATIONAccording to Federal Aviation Administration (FAA) records, the airplane was issued an airworthiness certificate on May 29, 2008, and was registered to a corporation. It was equipped with two Pratt & Whitney Canada W610F-A series, turbo fan engines that were each capable of producing 950 pounds of thrust. According to the pilot, the most recent annual inspection was performed on May 26, 2015. At the time of the accident, the airplane had accumulated 858.1 total hours.
According to the airplane flight manual, the braking system was "mechanically actuated and hydraulically operated. Braking was provided by hydraulically operated single disc brakes on each main gear. When pressure is applied to the toe brakes, hydraulic pressure is applied to the corresponding main gear brake."
The brake fluid reservoir was located outside the forward pressure bulkhead. "An optical sensor triggers a BRAKE FLUID LOW advisory message when the brake fluid is low."
The airplane manufacturer released a mandatory modification bulletin (MB 500-32-003) on April 3, 2015, pertaining to the Anti-Skid Brake System (ABS) Pressure Switch and Harness Route. The reason for the bulletin was to improve the harness routing and ABS installation. According to the pilot, the maintenance described in the modification bulletin had not been performed on the airplane, however, it was scheduled for a later date. METEOROLOGICAL INFORMATIONAt 1425, the recorded weather at DXR included wind from 350° at 6 knots, a few clouds at 6,000 feet above ground level, clear skies, 10 statute miles visibility, temperature 28° C, dew point 16° C, and an altimeter setting of 30.04 inches of mercury. AIRPORT INFORMATIONAccording to Federal Aviation Administration (FAA) records, the airplane was issued an airworthiness certificate on May 29, 2008, and was registered to a corporation. It was equipped with two Pratt & Whitney Canada W610F-A series, turbo fan engines that were each capable of producing 950 pounds of thrust. According to the pilot, the most recent annual inspection was performed on May 26, 2015. At the time of the accident, the airplane had accumulated 858.1 total hours.
According to the airplane flight manual, the braking system was "mechanically actuated and hydraulically operated. Braking was provided by hydraulically operated single disc brakes on each main gear. When pressure is applied to the toe brakes, hydraulic pressure is applied to the corresponding main gear brake."
The brake fluid reservoir was located outside the forward pressure bulkhead. "An optical sensor triggers a BRAKE FLUID LOW advisory message when the brake fluid is low."
The airplane manufacturer released a mandatory modification bulletin (MB 500-32-003) on April 3, 2015, pertaining to the Anti-Skid Brake System (ABS) Pressure Switch and Harness Route. The reason for the bulletin was to improve the harness routing and ABS installation. According to the pilot, the maintenance described in the modification bulletin had not been performed on the airplane, however, it was scheduled for a later date. ADDITIONAL INFORMATIONPerformance Study
A review of the DSU data revealed that the ground speed recorded at the weight on wheels (WOW) transition on the accident flight was the highest of the flights reviewed. Utilizing ground speed data, the time between WOW transition through 50 knots, the accident flight had the largest deceleration calculated from the available data, which was 2.2 knots per second (kts/s). The data for previous downloaded flights revealed a deceleration rate that averaged 0.7 kts/s. Although the airplane's calculated reference speed for the weight at the time of the accident was 89 knots and the target touchdown speed was 76 knots, the airplane's touchdown speed was 91 knots on the accident flight. However, the touchdown speed on the accident flight was 12 to 18 knots faster than the reviewed prior landings. In addition, integration of the airplane's recorded ground speed indicated that it touched down 1,280 feet from the threshold of Runway 26 and traveled 2,600 feet before coming to a stop, which was about 200 feet beyond the runway.
Landing Distance Data
According to the downloaded DSU data and the performance section of the airplane flight manual, under the conditions that existed at the time of the accident, the estimated landing distance required was approximately 3,063 feet when crossing the runway threshold at 50 feet above ground level. According to the recorded data, the airplane touched down 1,280 feet beyond the threshold of runway 26, which left 2,408 feet of the runway remaining since the displaced threshold was at 734 feet of the 4,422 foot runway.
Emergency Procedures
According to the Airplane Flight Manual, Section 3 Emergency Procedures, the Brakes Ineffective or Pulling to One Side procedure was to be used when the braking "with ABS becomes ineffective or causes the aircraft to pull to one side." The procedure included:
1. Maintain directional control using rudder and steering. 2. Brakes – Release. 3. ALL INTERRUPT – PRESS and HOLD 4. Reapply Brake (Pump Brakes as required) – Stop Normally
In an interview with a manufacturer representative, the pilot stated that he was not aware of that procedure until after the accident. In addition, he stated that he "was not trained" on the use of the ALL INTERRUPT button, which disabled the anti-skid brake system functions and restored normal braking, when the brakes were ineffective. TESTS AND RESEARCHExamination of the airplane by a representative from the manufacturer under the supervision of an FAA inspector noted that brake pressure was obtained on both sets of brake pedals when they were depressed. There was no bleed down or reduction in pedal firmness when the brakes were pumped several times. Both antilock brake system drive adapters were connected, and the wheel speed sensors rotated freely. In addition, the hydraulic reservoir was "full," and there were no leaks noted throughout the brake system, including the reservoir, brake lines, or around the brake assembly. No anomalies were noted during the examination of the brake system. Furthermore, in his written statement, the pilot did not report any crew alerting system messages or any alerts involving the brake system.
The Eclipse Aviation Diagnostic Storage Unit (DSU) was sent to the NTSB recorders laboratory for data download. A review of the data revealed that several parameters were recorded during the accident flight. In addition, the data revealed several sets of data from previous flights.