Accident Details
Probable Cause and Findings
The pilot's decision not to advance the engines to takeoff power during the go-around, as stipulated by the airplane flight manual, which resulted in an aerodynamic stall at a low altitude.
Aircraft Information
Registered Owner (Current)
Analysis
HISTORY OF FLIGHTOn July 27, 2010, about 1816 central daylight time, a Hawker Beechcraft model 390 (Premier IA) business jet, N6JR, collided with terrain while maneuvering to land on runway 18R at Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The airline transport pilot and passenger sustained serious injuries. The airplane sustained substantial damage. The airplane was registered to and operated by Roush Fenway Racing, LLC, as a business flight under 14 Code of Federal Regulations Part 91. Day visual meteorological conditions prevailed at the time of the accident. The cross-country flight departed Willow Run Airport (YIP), Ypsilanti, Michigan, at 1729, with OSH as the intended destination.
The pilot was flying to OSH to attend the Experimental Aircraft Association's Airventure 2010 fly-in convention. During the fly-in convention, a parallel taxiway east of runway 18 was used for takeoff and landings and was identified as runway 18L. The main runway, normally identified as runway 18, was denoted runway 18R and had a displaced threshold of 1,300 feet, leaving 6,700 feet of runway surface available for takeoffs and landings. During the fly-in convention, arriving aircraft were issued landing instructions and clearances by an air traffic control tower controller (tower controller) using a specified tower radio frequency. Departing aircraft were handled by another team of controllers operating on a separate radio frequency that was associated with a mobile operations/communications workstation (MOOCOW) located near the runway.
Air traffic control (ATC) data indicated that the accident airplane entered the Oshkosh area under visual flight rules. The pilot reported being on the Turbine/Warbird Arrival, a published arrival procedure used by jets and other high-performance aircraft during the fly-in convention. At 1811:18, the tower controller asked the pilot which runway he would like to use for landing. The pilot replied, "Uh, 18 or 27 would be okay." The tower controller told the pilot to expect a left base to runway 18R and to report over Warbird Island (a geographic reference point used for the approach procedure).
At 1813:31, the pilot reported being over Warbird Island. The tower controller cleared the pilot to land on runway 18R and to make his base turn abeam the control tower. The pilot read back the landing clearance correctly. At 1815:23, the tower controller told the pilot to turn northbound, onto a left downwind for the runway.
At 1815:54, the controller handling departing aircraft told the pilot of a yellow Piper Cub to taxi in position and hold on runway 18R. The pilot of the yellow Piper Cub acknowledged and requested an "... angled departure to stay clear of faster traffic." An angled-departure is a procedure used by slower aircraft to clear the runway immediately after liftoff by turning across the runway edge. At 1816:10, the controller handling departures transmitted, "Cub uh 18R cleared for takeoff as requested ... cleared for immediate takeoff." (A postaccident review of the cockpit voice recorder [CVR] indicated that the accident pilot was not monitoring the departure frequency, and therefore did not hear the radio transmissions made to the departing yellow Piper Cub.) Position data obtained from the accident airplane's enhanced ground proximity warning system (EGPWS) was synchronized with ATC communications. The synchronized data indicated that the accident airplane was turning to base leg when the yellow Piper Cub was cleared for immediate takeoff.
At 1816:19, the accident pilot transmitted to the tower controller, "Is ... is 6JR gonna be okay with this?" The tower controller responded, "Affirmative," to which the accident pilot replied, "I don't think so." The EGPWS position data indicated the accident airplane was still turning onto a base leg.
At 1816:21, the controller handling departures transmitted, "Cub as soon as you're airborne offset off the runway," and at 1816:33, told the pilot of the yellow Piper Cub to, "... turn left off the runway, traffic short final behind you." At 1816:36, the controller handling departures continued, "Thank you sir, doing a good job." A review of an amateur video synchronized with ATC voice recordings and the EGPWS data indicated that the accident airplane was turning from base to final when the controller transmitted the "good job" comment to the pilot of the yellow Piper Cub. The final segments of the accident flight were below available radar coverage; as a result, radar track data could not be used to establish separation between the accident airplane and the departing yellow Piper Cub.
At 1816:35, the CVR recorded the EGPWS announcing "bank angle" five times until 1816:40. During the same time period, the CVR recorded a rapid increase in engine sound. At 1816:40, the accident pilot transmitted "Going around" as the engine sound peaked. Review of the synchronized amateur video showed that the accident airplane had pitched up at that time. Beginning at 1816:41, the CVR recorded a decrease in engine sound over a period of 6 seconds. During the same time period, the EGPWS announced "bank angle" two additional times.
At 1816:46, the tower controller acknowledged the go-around stating, "Alright premier jet uh use caution for the uh traffic ahead on the upwind and uh..." During this controller transmission, the CVR recorded an incremental increase of engine sound over 6 seconds until 1816:54. At 1816:54 the EGPWS announced "bank angle" two more times. The engine sound remained steady until the CVR recorded a sound similar to impact at 1816:57. A continuous high-pitched tone was recorded by the CVR immediately before impact. The airplane was equipped with a stall warning horn.
A review of available EGPWS position data depicted the accident airplane turning from downwind in a continuous left turn to final for runway 18R. During the final portion of the turn, the recorded bank angles were between 32 and 43 degrees left-wing-down (LWD). The airplane overshot the runway during that turn. The EGPWS data also showed that the airplane descended from 185 feet to 37 feet above the ground (radar altitude) during the turn to final. After the overshoot, the airplane momentarily leveled its wings before entering a climb for about 6 seconds. The airplane climbed from 37 feet to 117 feet above the ground, as it entered a left bank (reaching 30 degrees LWD). The airplane then entered a descending right turn, at an increasingly higher angle-of-attack and rate-of-descent. The maximum bank angle was 44 degrees right-wing-down during the 5 seconds before impact. The angle-of-attack was between 11 and 16 degrees and the maximum descent rate was 1,972 feet per minute during the same time period.
The accident airplane's flight path depicted on the amateur video was consistent with the available EGPWS data. During the final descent the airplane's pitch appeared to increase until the airplane entered a right bank and struck the grass area west of the runway in a nose down, right wing low attitude. The video showed a yellow Piper Cub appearing after the accident airplane had overshot the final approach. At that time, the wing profile of the yellow Piper Cub was consistent with a southeasterly heading, away from runway 18R.
The pilot was interviewed on August 30, 2010, by an Operational Factors investigator with the National Transportation Safety Board (NTSB). The pilot reported that he had departed YIP on an instrument flight rules (IFR) flight plan to Milwaukee, Wisconsin; however, he canceled the flight plan while en route and continued to OSH under visual flight rules. He stated that he flew the Turbine/Warbird Arrival and that the tower controller told him to expect runway 18R. He noted that he was not given an option of available runways. While on base and during his turn to final, he identified two airplanes operating from runway 18R. One of the airplanes was already airborne and approaching the departure end of the runway. The other airplane, a yellow Piper Cub, was on takeoff roll. The accident pilot reported that while on base leg, he became concerned that his descent path to the runway would conflict the Piper Cub that was on takeoff roll. He stated that he overshot the runway during his turn from base to final, and when he completed the turn the accident airplane was right of the runway. The pilot stated that at this point he decided not to land because of a perceived conflict with the departing Piper Cub (which was flying ahead and to the left of the accident airplane). He recalled seeing the yellow Piper Cub over the runway 18R centerline. The pilot reported that he initiated a go-around, increasing engine power slightly, but not to takeoff power, as he looked for additional traffic to avoid. He estimated that he advanced the throttle levers "probably a third of the way to the stop" and, as he looked for traffic, the stall warning stick-shaker and stick-pusher systems activated almost simultaneously as the right wing stalled. He did not recall hearing a stall warning horn sound. He stated that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane.
The air traffic controllers working the final portion of the accident flight were interviewed on July 28, 2010, by a NTSB Air Traffic Control Investigator. The MOOCOW aircraft spotter/coordinator stated that he was made aware of an inbound Premier IA jet via notification by the control tower supervisor over an FM radio link used for coordination between the control tower and the MOOCOW. The control tower supervisor made two status calls; one as the Premier IA jet was on downwind, and another when it turned onto left base. The aircraft spotter/coordinator stated that in response to the first status call he directed the aircraft communicator (for departing aircraft) to clear the yellow Piper Cub for an immediate takeoff and to sidestep off the run...
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN10FA443