Maryland

The airplane 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. 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 of the single-engine turboprop was on an instrument flight rules (IFR) flight and cancelled his IFR flight plan after being cleared for a visual approach to the destination airport. He flew a left traffic pattern for runway 32, a 4,202-foot-long, 75-foot-wide, asphalt runway. The pilot reported that the airplane crossed the runway threshold at 81 knots and touched down normally, with the stall warning horn sounding. The airplane subsequently drifted left and the pilot attempted to correct with right rudder input; however, the airplane continued to drift to the left side of the runway. The pilot then initiated a go-around and cognizant of risk of torque roll at low speeds did not apply full power. The airplane climbed to about 10 feet above the ground. At that time, the airplane was in a 20-degree left bank and the pilot applied full right aileron input to correct. The airplane then descended in a left turn, the pilot retarded the throttle, and braced for impact. A Federal Aviation Administration inspector reported that the airplane traveled about 100 feet off the left side of the runway, nosed down in mud, and came to rest in trees. Examination of the wreckage by the inspector did not reveal any preimpact mechanical malfunctions, nor did the pilot report any. The reported wind, about the time of the accident, was from 310 degrees at 10 knots, gusting to 15 knots.

The flight was conducting a straight-in approach during visual meteorological conditions. The approach was backed up by an ILS and was stable at 500 feet above touchdown. The initial touchdown was firm and main landing gear rebounded, possibly bouncing slightly off the runway. Control column input and possibly momentum from the touchdown resulted in a rapid pitch down and hard nose gear impact with the runway. Wing spoilers likely did not deploy due to the main gear bounce and/or throttle position. Following the nose gear impact, the airplane pitched up as expected and the column was held in a slightly forward position. Airspeed rapidly decayed, and engine power began to increase as the airplane pitch reversed to a downward motion for a second time. One of the crew, likely the FO, called “flare flare” and the column recorded a rapid nose up input, followed by a rapid nose down input, and the nose gear again struck the runway very hard, likely causing the majority of the damage at that point. Following the second nose gear impact, column inputs stabilized at a slightly nose up command, power was set on all three engines, and the go-around was successfully executed. A slight lag in the power increase on engine number 3 may have contributed to the nose down motion leading to the second nose gear impact, although the large forward (airplane nose down) column movement appears to be a much more significant contributor. It is unclear why the engine was slower to increase. Throttle lever angle was not recorded, but the engine operated as expected for all other phases of the flight, including after the impact, therefore it is possible the pilot did not advance the number 3 throttle concurrently with the others. The captain’s flight and duty schedule complied with Federal Aviation regulations, but he experienced a demanding 10-day trip schedule prior to the incident involving multiple time zone crossings and several long duty periods, and reported difficulties sleeping prior to the accident leg. The captain was likely further affected by a digestive system upset during the accident flight. It is likely that the captain’s performance was degraded by fatigue and some degree of physical discomfort brought on by a short-term illness. The captain had recently completed upgrade training to DC-10, having previously been flying as an MD-11 first officer. The training program was fragmented over approximately ten months, and while in accordance with FAA regulations, may have adversely affected his consolidation of skills and experience.

The airplane was loaded to within a few hundred pounds of its maximum gross takeoff weight, and departed from an airport located in a valley, surrounded by rising terrain. Although visual conditions prevailed at the accident airport, fog was present in the adjacent valleys. During the initial climb after takeoff, the right engine lost partial power due to a failure of the number one cylinder exhaust valve. The pilot secured the right engine; however, he was unable to maintain a climb with only the left engine producing power. The airplane was manufactured in 1964. Review of weight and performance data published at the time of manufacture, revealed that the airplane should have been able to climb about 400 feet-per-minute with a single engine producing power. No current weight and balance data was recovered, and due to impact and fire damage, the preimpact power output of the left engine could not be determined. Both engines were last overhauled slightly more than 12 years prior to the accident, and flown about 310 hours during that time. For the make and model engine, the manufacturer recommended overhaul at 1,200 hours of operation, or during the twelfth year.

With all cockpit indications showing the landing gear was down and locked, the airplane touched down on the runway. Immediately after touchdown, the pilots heard the landing gear warning horn sound intermittently for several seconds, and then the right main landing gear collapsed. The airplane veered to the right, exited the runway, and came to rest. A post crash fire ensued, and the crew exited without injury. A postaccident examination of the airplane revealed that the collapsed right main landing gear had penetrated the right main fuel tank and the majority of the right side of the fuselage had been consumed by fire. Examination of the left and right main landing gear assemblies revealed, that both downlock plates had been installed backwards, providing only a fraction of the design contact area between the plate and throat of the downlock hook. Examination of the manufacturer's component maintenance manual, which was used for the assembly and installation of the left and right main landing gear, revealed no guidance regarding downlock plate orientation during installation.

The pilot was finishing his third round-trip, Part 135 cargo flight. The first round trip began the previous evening, about 2150, and the approach back to the origination airport resulted in a landing on runway 15R at 2305. The second approach back to the origination airport resulted in a landing on runway 28 at 0230. Prior to the third approach back to the airport, the pilot was cleared for, and acknowledged a visual approach to runway 33R twice, at 0720, and at 0721. However, instead of proceeding to the runway, the airplane flew north of it, on a westerly track consistent with a modified downwind to runway 15L. During the westerly track, the airplane descended to 700 feet. Just prior to an abeam position for runway 15L, the airplane made a "sharp" left turn back toward the southeast, and descended into the ground. Witnesses reported the airplane's movements as "swaying motions as if it were going to bank left, then right, and back left again," and "the nose...pointing up more than anything...but doing a corkscrew motion." Other witnesses reported the "wings straight up and down," and "wings vertical." Tower controllers also noted the airplane to be "low and tight," and "in an unusually nose high attitude close to the ground. It then "banked left and appeared to stall and then crashed." A post-flight examination of the wreckage revealed no evidence of mechanical malfunction. The pilot, who reported 6,800 hours of flight time, had also flown multiple round trips the previous two evenings. He had checked into a hotel at 0745, the morning prior to the accident flight, checked out at 1956, the same day, and reported for work about 1 hour before the first flight began.

The pilot reported that he ran the engines to full power before releasing the brakes. Immediately after lift-off, when he retracted the landing gear, he noticed a dramatic loss of airspeed. The airplane began to rock back and forth, and the pilot's efforts to increase the airspeed including lowering the nose and adding full power was unsuccessful. According to the Piper Information Manual for a short field takeoff, a lift-off speed of 85 mph and 15 degree of flaps is required. The reported winds were 010 degrees at 7 knots. The pilot departed runway 29 which is 2910 feet long. A witness who was refueling an airplane on the ramp stated that the airplane was still on the runway at the 500 foot mark from the end of runway 29.

The airplane collided with trees shortly after takeoff and came to rest in a church yard. There were no witnesses to the crash; however, several local residents heard the airplane overfly their homes at a low altitude. One resident stated that he heard the airplane collide with the trees. Another resident stated that he heard the engine operating as the airplane flew low overhead. Both residents reported that reduced visibility hampered their ability to find the wreckage. One resident estimated that the visibility was about 50 to 60 feet. The prescribed takeoff minimums for that airport is 300 feet and 1 mile visibility. Examination of the airplane did not disclose evidence of mechanical malfunction. The pilot, sole on board, was killed.

The pilot supervised the loading of the airplane. According to info from a person that helped load the plane, the bill of loading, and actual weights and measurements of the cargo after the accident, the plane was loaded to a gross weight of 11,979 lbs with the cg 2.7 inches behind the aft limit. At the destination, the flight was vectored for an ILS runway 10 approach. About 3 miles from the runway, the pilot was told to make a missed approach due to inadequate separation from traffic. The pilot acknowledged, but soon thereafter, radar contact with the plane was lost. Witnesses saw the plane descend from a low cloud layer before it crashed. One witness said its wings were moving from side to side and the plane was falling faster than it was moving forward. There was evidence the plane had impacted in a flat attitude with little forward movement. Four cargo straps were found loose with no sign of tensile overload; 3 others and a restraining board were found loose as if they had not been used. No preimpact mechanical problem was found. The wind was from 090° at 21 gusting 32 kts. The pilot, sole on board, was killed.

The pilot reported that shortly after takeoff on a parachute jumping flight the left engine lost power, but a second later power was restored. Soon afterwards a total power loss occurred. According to the pilot, the propeller stopped rotating and did not windmill. He did not feather the left propeller. He made a shallow left turn toward an open field, while trying to return to the airport. He was unable to maintain adequate airspeed or altitude, and in order to maintain aircraft control, he reduced power on the right engine. He made a forced landing in a wheat field. The airplane came to a stop and all occupants escaped the airplane before it caught fire. The examination of the airplane did not disclose evidence of mechanical malfunction.