CEN15FA311

The pilot's failure to perform a go-around after receiving a modified landing clearance and his failure to maintain adequate airspeed while maneuvering to land, which resulted in the airplane exceeding its critical angle of attack in a steep bank and entering an accelerated stall at a low altitude.

The pilot was landing at a large fly-in/airshow and following the airshow arrival procedures that were in use. While descending on the downwind leg for runway 27, the pilot was cleared by a controller to turn right onto the base leg abeam the runway numbers and to land on the green dot (located about 2,500 ft from the runway's displaced threshold). About the time the pilot turned onto the base leg, he observed an airplane taxi onto the runway and start its takeoff roll. The controller instructed the pilot to continue the approach and land on the orange dot (located about 1,000 ft from the runway's displaced threshold) instead of the green dot. The pilot reported that he considered performing a go-around but decided to continue the approach. As the pilot reduced power, the airplane entered a stall and impacted the runway in a right-wing-low, nose-down attitude. Witnesses estimated that the bank angle before impact was greater than 60 degrees. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Analysis of a video recording of the accident showed that the airplane was about 180 ft above ground level (agl) when the turn onto the base leg began, and it descended to about 140 ft agl during the turn. The airplane's total inertial speed (the calculated vector sums of the airplane's ground speeds and vertical speeds) decreased from 98 knots (kts) to 80 kts during the turn. During the last 8 seconds of flight, the speed decreased below 70 kts, and the airplane descended from about 130 ft agl to ground impact. The wings-level stall speed of the airplane at maximum gross weight with landing gear and flaps down was 59 kts. In the same configuration at 60 degrees of bank, the stall speed was 86 kts and would have been higher at a bank angle greater than 60 degrees. Reduced runway separation standards for airplanes were in effect due to the airshow. When the accident airplane reached the runway threshold, the minimum distance required by the standards between the arriving accident airplane and the departing airplane was 1,500 ft. The video analysis indicated that it was likely that a minimum of 1,500 ft of separation was maintained during the accident sequence. Although the pilot was familiar with the procedures for flying into the airshow, the departing airplane and the modified landing clearance during a period of typically high workload likely interfered with the pilot's ability to adequately monitor his airspeed and altitude. As a result, the airplane entered an accelerated stall when the pilot turned the airplane at a steep bank angle and a low airspeed in an attempt to make the landing spot, which resulted in the airplane exceeding its critical angle of attack. At such a low altitude, recovery from the stall was not possible. Although the airshow arrival procedures stated that pilots have the option to go around if necessary, and the pilot considered going around, he instead continued the unstable landing approach and lost control of the airplane.

HISTORY OF FLIGHT On July 22, 2015, about 0744 central daylight time, a Piper Malibu PA-46-310P single-engine airplane, N4BP, sustained substantial damage when it impacted runway 27 (6,179 ft by 150 ft, concrete) while landing at the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The pilot and two passengers sustained serious injuries and two passengers sustained minor injuries. The airplane was registered to DLM Holding Group LLC and operated by the pilot under the provisions of the 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The flight departed the Southwest Michigan Regional Airport (BEH), Benton Harbor, Michigan, about 0730 eastern daylight time. The pilot reported that he departed BEH and overflew Kenosha, Burlington, Hartford, Ripon, and Fisk, Wisconsin. He then proceeded to fly the Fisk arrival procedures for runway 27 which were in use per the notice to airmen (NOTAM) for the EAA AirVenture 2015 air show at OSH. The pilot reported that he entered the right downwind leg for runway 27 at 1,800 ft and started to descend while maintaining 90 kts airspeed. He reported that he was instructed by air traffic control (ATC) to turn onto the base leg abeam the runway numbers and to land on the green dot (located about 2,500 ft from the runway 27 displaced threshold). After he started the base turn, he observed a twin-engine airplane taxi onto runway 27 and start its takeoff roll. (A passenger in the Malibu identified the airplane on the runway as a Cessna "high-wing 4-seater") The pilot was concerned about the airplane on the runway and was worried about a collision. The pilot reported that ATC instructed him to continue the approach and land on the orange dot (located about 1,000 ft from the runway 27 displaced threshold) instead of the green dot. The pilot considered doing a go-around, but decided to continue the approach. He reported that about 250 to 300 ft above ground level, he pulled back on the power which resulted in the airplane entering a stall. He attempted to recover by adding full power, but the airplane impacted the runway in a right wing low, nose down attitude. The right wing hit the runway which resulted in an explosion with fire and black smoke rising above the accident site. The right wing separated from the airplane and landed in the grass on the south side of the runway. The airplane skidded on its belly and came to rest on the left side of the runway about 278 ft from the initial impact point. The left wing was partially separated from the fuselage and there was a fire under the left wing. The two passengers who were sitting in the middle, rear-facing seats, and the passenger sitting in the rear seat exited the airplane with assistance from the pilot and people who arrived at the site soon after the accident. The Crash Fire Rescue (CFR) personnel arrived at the scene and used foam to put out the fire. The passenger sitting in the copilot's seat was extracted from the wreckage by the CFR. All five survivors were taken to local hospitals for treatment. Numerous witnesses reported that they saw the airplane on the base leg as it entered a steep right bank and impact the terrain in a steep nose down, right wing low attitude. One witness reported that he was located on the terminal ramp to the north of the approach end of runway 27. He heard an aircraft approaching from over the terminal building and observed that the airplane was very low – less than 200 ft above ground level (agl). The witness said that there was no indication that the airplane was in distress, such as a sputtering engine. He further reported that the airplane entered a steep right turn, with an estimated angle of bank of over 60 degrees and then impacted on its side with the right wing contacting the ground first. AIR TRAFFIC CONTROL COMMUNICATIONS Special procedures and staffing for ATC were in effect during the Experimental Aircraft Association's AirVenture event. The North Local Control (NLC) team was located in the control tower. The team consisted of five controllers: two spotters, one communicator, a team leader, and a front-line manager (FLM) overseeing the operation. At the time of the accident, the NLC team was responsible for issuing landing clearances on runway 27. The Itinerant Mobile (IM) team, who had overall responsibility for ATC departure operations on runway 27, was working from a Mobile Operations Communications Workstation (MOOCOW) located at the intersection of runway 27 and taxiway A. The IM team was responsible for clearing aircraft for takeoff on runway 27 and consisted of four controllers: an aircraft communicator (AC), one spotter/coordinator, and two "crossers" who work directly with aircraft holding for departure on the taxiway. Communication between the IM and NLC teams was conducted via portable FM (frequency modulation) radios used by the MOOCOW AC and the NLC FLM, although coordination was kept to a minimum. The IM team was responsible for ensuring separation between arrivals and departures by monitoring the inbound pattern traffic and releasing departures when there was sufficient time to do so before the next aircraft landed. Instructions for the Fisk arrival contained in the AirVenture NOTAM direct pilots to minimize radio transmissions and not respond to ATC communications. Review of recorded transmissions from the NLC team and the IM team showed that at 0742:24, the NLC communicator instructed a Malibu on downwind for runway 27 to begin descent. At 0742:44, the Malibu pilot was told to, "…turn abeam the numbers, runway 27 green dot cleared to land." Before and during the period the Malibu was operating in the traffic pattern, the IM team was clearing departures for takeoff from runway 27. Between 0730 and 0743 there were about 22 departures. The last departure before the accident was "Cessna 44Q", cleared for takeoff at 0743:03. The IM communicator then continued, "44Q roll it around the corner – scoot!" At 0743:11, the NLC communicator transmitted, "Malibu I've got somebody on the runway – keep it coming around keep it coming around cleared to land runway 27 orange dot, land as soon as you can." At 0743:23, the IM communicator transmitted, "Don't turn your back – don't turn your back!" There were no further transmissions on the IM frequency. The tower controllers notified airport firefighters to respond, extinguish the post-crash fire, and assist the aircraft's occupants. The IM communicator reported that the Malibu looked "normal" on downwind over the gravel pit, but the next time he saw it, the aircraft looked unusually low for a runway 27 arrival. The Malibu was west of the terminal building and had not yet started to turn right base. The next departure was holding short between 125 and 250 feet from the runway. Traffic was very light, and there were no other aircraft waiting to depart. The communicator cleared the Cessna for takeoff. The communicator then observed that the Malibu was lower and "tighter" on base than he expected, so he went on frequency and told the Cessna pilot to hurry up. The Cessna pilot never stopped, and made a rolling takeoff as requested. The Malibu was over the terminal building and then turning toward the runway. The communicator reported that by then, the departing Cessna was rolling and approaching or beyond the green dot on the runway. The communicator reported that the Malibu was on downwind west of the terminal building, and had not turned base yet when the Cessna was cleared for takeoff. He stated that controllers try to use minimum spacing during AirVenture, and to expedite traffic to avoid go-arounds. Because arriving aircraft were on the NLC frequency, the IM communicator could not directly instruct a pilot to go around. Should a go-around appear necessary, the IM team would contact the tower FL