Accident Details
Probable Cause and Findings
failure of the flight crew to maintain minimum control speed (Vmc) during go-around from a single-engine approach, which resulted in loss of control and collision with power lines and the ground. Related factors were: a ruptured diaphragm in the distributor valve (flow divider) of the right engine's fuel injector system, which resulted in loss of power in the right engine; inadequate maintenance; a failure to comply with Bendix Service Bulletin RS-76; the airplane's excessive gross weight and forward center-of-gravity (CG); and both pilots' lack of experience in this make and model of airplane.
Aircraft Information
Registered Owner (Historical)
Analysis
HISTORY OF FLIGHT:
On January 10, 1998, at 1427 central standard time, an Aero Commander 500-B twin engine airplane, N556BW, owned and operated by MGS Corporation of Laredo, Texas, was destroyed following collision with terrain while executing a single engine go-around. The private pilot, who was seated in the left seat, and the instrument rated commercial pilot, who was seated in the right seat, were fatally injured. A pilot rated passenger seated in the cabin received serious injuries. An instrument flight plan was filed for the Title 14 CFR Part 91 personal cross country flight, that originated from the Lancaster Municipal Airport, Lancaster, Texas, at 1415. The flight's original destination was Laredo, Texas; however, it was diverting to Ennis, Texas, at the time of the accident.
During personal interviews, conducted by the investigator-in-charge (IIC), witnesses reported that the airplane entered a close right base to final entry for runway 15 at the Ennis Municipal Airport. One witness, residing along the final approach path, observed the airplane's wings "rocking" on the approach, and at about 100 feet from the approach end of the runway, the right wing went 45 degrees low and then vertical to the ground. Near the midpoint of the runway length this witness observed the airplane entering a climb with the gear down and the left propeller turning. Another witness, residing along the final approach path, observed the airplane flying south with the left wing low and the airplane weaving back and forth toward the left side of the runway. Subsequently, the airplane flew over the runway, turned right, and descended to the ground.
Several witnesses at the airport, observed the airplane flying to the south at "50 to 75 feet above the ground. The aircraft was in a landing configuration, landing gear down, flaps down and the nose of the aircraft was up approx[imately] 10 degrees, the right engine was feathered, the aircraft was slow on airspeed." The airspeed was estimated between "70 mph and 100 mph, the wings were basically level with maybe just a little left wing low condition. The left engine was not developing full power." The airplane was "sinking." The airplane "banks shallow into the right side and in a full stall to the right." The right wing hit the ground first and then the nose of the airplane.
The passenger reported that he was seated in the rear facing seat behind the right cockpit seat. He wore a headset that permitted him to hear the cockpit voice communications as well as radio communications. The pilot's delayed the departure from Lancaster due to the weather, and the non-flying pilot (right seat) requested a second departure time from ATC. The passenger stated that the flight departed runway 13 on an IFR clearance. The non-flying pilot handled the IFR radio communications with departure control, and the flying pilot (left seat) flew the airplane. During the climb, the airplane was above the clouds approximately 4,000 feet msl, when there was a "surging of the engine followed by a total loss of engine power on the right engine." The pilots conversed about "low fuel flow to the right engine." The non-flying pilot applied rudder pressure and assisted the flying pilot in performing the emergency checklist. The passenger stated that the airplane was not maintaining altitude and the pilots verified and feathered the right engine. Flight in VFR conditions was maintained for the visual approach to the Ennis Municipal Airport.
The passenger further stated that everything "seemed textbook perfect and neither [pilot] seemed overly concerned about anything." As the airplane entered the base to final transition, the pilots agreed that they did not want to do a go-around. The airplane was aligned with runway 15 at Ennis with the landing gear extended. At a point where it looked to the passenger that they had the runway made for the landing, the passenger turned to a rearward facing position and tightened his seatbelt.
As time passed and the passenger felt that they should have been landing, he turned around and looked forward. He reported that the airplane was over halfway down the length of the runway; however, not aligned with the runway. The airplane was about 30 degrees to the right of the runway and aligned with the hangars. The "airspeed felt quite slow and we did not appear to be more than 40 feet agl." The flying pilot said "at least I can get the gear up" and he began to raise the landing gear handle. Within a fraction of a second after the gear handle was raised, the nose of the airplane pitched up approximately 10 degrees. Before the passenger could turn back facing rearward, the "left wing started up in what I believe to be a Vmc roll." The airplane rolled to the point that the wing was perpendicular to the ground before the first of two impacts. The airplane came to rest inverted. The passenger released his seat belt and exited through the passenger door. The passenger walked toward the road where he was encountered by a fire department medic responding to the site. The passenger stated that he "heard no conversation and saw nothing to indicate why we did not land before we were out of airspeed, runway, and altitude."
The passenger further stated that the fuel flow gauge was fluctuating during the inflight "surging of the engine." Acquaintances of the pilots, at the Lancaster airport, reported that the flying pilot was going to fly the airplane to Laredo, Texas, following maintenance repair of the left wing fuel tanks and the magneto timing. Due to the instrument weather conditions in the vicinity of Lancaster, the non-instrument rated pilot asked the instrument rated pilot to go on the flight and handle the IFR communications and procedures.
PERSONNEL INFORMATION:
The flying pilot was a non-instrument rated private pilot with single and multiengine land ratings. The pilot was issued a third class medical certificate on April 2, 1997. On the medical application, the pilot's total flight time was shown as 1,550 hours with 15 hours in the previous 6 months. According to the owner of the aircraft, the private pilot flew the airplane for "maybe 10 minutes" on December 21, 1998, during a maintenance flight check. No additional information on the pilot's flight time in the make and model of aircraft could be obtained.
The non-flying pilot held a commercial pilot certificate with single and multiengine land, and instrument ratings. He held a flight instructor certificate with single engine, multiengine, and instrument ratings. The non-flying pilot satisfactorily completed an FAA FAR 135 check ride on November 4, 1997, in the Piper PA-34-200 multiengine airplane. The commercial pilot's logbook indicated a total flight time of 4,833.4 hours through December 28, 1997. The logbook indicated 24.4 hours of flight time in the Piper PA-34-200 multiengine airplane in the previous 90 days. Both pilots held a mechanic certificate with airframe and powerplant ratings with FAA Inspection Authorization.
The pilot rated passenger held a private pilot certificate with a single engine land rating. He owns a single engine airplane and flies regularly from Lancaster to Laredo. He stated that he had 35 hours of dual instruction in an Aero Commander 560-A twin engine airplane.
AIRCRAFT INFORMATION:
The aircraft (S/N 1625-215) was manufactured in 1966. The airplane was imported from Canada to the United States and issued the FAA registration number of N95BS and a standard airworthiness certificate on May 4, 1992. In 1996, the FAA registration number was changed to N556BW. On March 11, 1997, a pre-purchase inspection and engine run performed at Downtown Airpark, Inc., Oklahoma City, Oklahoma, revealed numerous discrepancies including fuel pressure fluctuations, fuel flow fluctuations, and exhaust stack cracks.
During telephone interviews, conducted by the IIC, the current owner reported that he reviewed the pre-purchase inspection that had been accomplished for the previous potential buyer. The airplane was purchased from Aircenter, Inc., Chattanooga, Tennessee, by the current owner in April 1997, and registered with the FAA on September 15, 1997. The owner's pilot reported that the airplane was ferried to Laredo, Texas. During a flight checkout by the ferry pilot and a subsequent flight to San Antonio, Texas, the owner's pilot "found no discrepancies of note."
The airplane has flown 23.6 hours since the last annual inspection on August 8, 1997. During the 16.6 hours flown by the current owner's pilot, the airplane experienced fuel flow fluctuations on the right engine and sometimes the right engine would not continue to run without the auxiliary boost pump operating. An aircraft maintenance discrepancy log, dated August 25, 1997, listed non corrected discrepancies including low fuel flow, left wing fuel leaks, a fuel shutoff valve leak, and exhaust leaks. The right inboard and aft fuel tanks were removed and replaced, and the fuel lines, screens, and injectors were checked and cleaned at Barker Aeromotive, Inc., Laredo, Texas. The mechanic and the pilot thought that the "debris in the fuel filters and lines could be paint blast media" since the airplane had been repainted. During a telephone interview, conducted by the IIC, personnel at the paint facility, Dan Smith Aircraft, Houston, Mississippi, stated that they painted the aircraft in 1996, and "the chemical stripping process did not involve the use of blast media."
On September 8, 1997, the airplane was flown to Lancaster, Texas, for exhaust system maintenance. During the descent and upon landing at Lancaster, it was discovered that fuel was leaking from the left wing. The aircraft remained at Quinnex where the right and left fuel injector servos and nozzles were removed and sent to J & G Aero Carburetor, Dallas, Texas, for repair, and reinstalled on the engine. The fu...
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# FTW98FA092