BANGOR, ME, USA
N139ZV
Beech 1900D
During takeoff roll, as the FO rotated the airplane, the stall warning horn activated. The airplane lifted from the runway with the stall horn on, and above V1 speed the PIC called out to abort. The FO aborted the takeoff and landed the airplane on the runway. The airplane then entered a snow bank on the left side of the runway. Service Difficulty Reports revealed other stall horn activation's had occurred on takeoff; several occurred after deicing and were attributed to frozen stall vanes on the wing. The accident airplane had been deiced prior to the takeoff. The BE1900 check list called for the stall vane heat to be turned on just before takeoff. Stall training provided by the operator did not include BE1900 simulators, and all recoveries were initiated at the stall horn. The FAA practical test standard for type ratings required the recognition of the stall buffet, stick shaker, or decay of control effectiveness. The flight crew had not received winter operations training, and this was the Boston based PIC's third takeoff in snow. Multiple FAA inspections over several years revealed the Operator was not in compliance with regulations, which included their training program; however, they continued to operate unrestricted. Airport operations had ceased snow plowing the 300 foot wide runway to accommodate airline operations, and reported the runway had been plowed 75 feet west and 150 feet east of runway center. The runway was measured to be plowed 55 feet left of center, with a 1 foot high, and 10 foot wide pile of snow on the west side of the runway. The plowed portion had an icy covering.
HISTORY OF FLIGHT On January 10, 1997, at 0923 eastern standard time, a Beech 1900D, N139ZV, operated by Mesa Airlines, Inc., doing business as USAir Express Flight 5326, was substantially damaged during an aborted climb after takeoff at the Bangor International Airport, Bangor, Maine. The certificated airline transport captain, first officer, and seven passengers were not injured. Two passengers received minor injuries. Instrument meteorological conditions prevailed for the scheduled passenger flight, destined for Boston, Massachusetts. An instrument flight rules flight plan had been filed for the flight conducted under 14 CFR Part 135. The airplane had been flown by the flight crew from Boston, to Bangor International (BGR), and arrived, at 0856. The airplane was fueled, passengers were boarded, and the flightcrew started the engines and taxied to the de-icing area. While in the de-icing area, the engines were shut down and airplane de-icing was initiated at 0912, and completed at 0917. The engines were restarted, and the airplane was taxied to runway 33 for takeoff. At 0921, Flight 5326 was cleared for takeoff by the BGR tower controller. The first officer (FO) stated that she was the flying pilot. The FO briefed the captain that this was to be a zero degree flap takeoff, and repeated the takeoff speeds to be used. After taxing onto the runway, the FO applied power, began the takeoff roll, and requested that the captain set the final takeoff power. The cockpit voice recorder (CVR) transcript revealed the following: the flight crew called out the "takeoff final items," at 0921:10; which included ice protection items, at 0921:21; the propeller RPM was heard to increase, at 0921:59; and the FO called out "set takeoff power," at 0922:09. The captain then made the following callouts: "eighty knots cross checked," at 0922:12; "the wind is from the right," at 0922:17; and "V one rotate," at 0922:19. The CVR revealed the sound of a horn, at 0922:21, which was similar to the stall warning horn. At 0922:26, the captain called out, "abort abort." The sound of the horn ceased, at 0922:28, and the captain called out, "abort Doris Doris," at 0922:29. The CVR recorded the sounds of impact and the recording ended, at 0922:31. The FO stated that at Vr, she pulled the yoke back with both hands, raised the pitch of the airplane into the command bars, and heard the stall warning horn sound as the airplane rotated. She stated that she released "a little back pressure," observed the airspeed indicator at 120 knots, and applied more back pressure. The airplane then left the ground, but it felt sluggish. She estimated that the airplane was about 20 feet above the runway when the captain commanded, "Abort! Abort!" The FO closed the throttles and the airplane contacted the ground approximately on the centerline of the runway. She stated that, "visibility went to zero because of the flying snow." She then brought the "throttles to Ground Fine," and felt the captain's hand on top of hers as she moved the throttles into reverse. According to one passenger, the airplane lifted from the runway and the engines were "whining as we started to climb." The passenger also stated: "...Very shortly we seemed to level off and then it appeared to me that the pilot was aborting the takeoff...I heard a loud snap and suddenly the fuselage was ripped open..." Another passenger stated: "...Rolled onto runway, turned right and proceeded with takeoff. (noted: that there was not spool up to full power with brakes applied before takeoff.) Plane took off and gained 10 - 20 feet altitude. Heard the stall alarm and pilot aborted take-off putting back down on runway, landing about 15 [degree] angle to the right of center line. Nose gear gave way. Right engine propellers broke-off and came through cabin..." After touch down, the airplane veered left into the snow bank on the runway. The airplane pivoted 90 degrees nose right as it traveled through the snow bank while still on the runway, and exited the snow about 819 feet from the point of entry. The crew and passengers exited through the overwing exits and the main cabin door. During an interview, the Captain stated that he checked the stall warning vane prior to his leaving the accident site, and found ice had frozen the stall warning vane in position. He said he wiggled the vane and broke it free of ice holding it in place. The accident occurred during the hours of daylight approximately 44 degrees, 48 minutes north latitude, and 68 degrees, 49 minutes west longitude. FLIGHT CREW INFORMATION Captain The Captain held an Airline Transport Pilot Certificate with a rating for airplane multiengine land, and was type rated in the Beech 1900, with the limitation that a second in command was required. He also held a Commercial Pilot Certificate for airplane single engine land. His most recent Federal Aviation Administration (FAA) First Class Medical Certificate was issued on December 6, 1996. The Captain was hired by Mesa Airlines on October 10, 1994, and flew as a First Officer (FO) on the Embraer 120. He was upgraded to Captain in the Beech 1900, and took his type rating check ride in July, 1996. Since the check ride, the Captain estimated that he had flown about 350 to 400 hours in the Beech 1900, all of which was pilot-in-command (PIC). He reported that his total flying experience was about 5,800 hours. During an interview with the Captain, he stated that he had received no crew resource management (CRM) training. He recalled that he did receive "some" winter operations training during his initial hire training in October, 1994. He also stated that he was unfamiliar with operations in snow conditions, and that this was only his third takeoff and landing in snow. The Captain's base of operation with Mesa was Boston. First Officer The First Officer (FO) held an Airline Transport Pilot Certificate with a rating for airplane multiengine land, and was type rated in the Cessna 650. She also held a Commercial Pilot Certificate with ratings for airplane single engine land and glider. The FO held a Flight Instructor Certificate with ratings for airplane single engine land, glider, and instrument airplane. Her most recent FAA First Class Medical Certificate was issued on August 8, 1996. The FO was hired by Mesa Airlines in September, 1995. She received her initial training in the Beech 1900, and had accumulated about 1,100 hours of second-in-command experience in make and model. The FO reported that her total flying experience was approximately 4,100 hours. During an interview with the FO, she stated the she had received "a good 1 1/2 hours of CRM," during her recurrent training in August, 1996. The FO did not recall any winter operation or de-icing training, but did state that winter operations were "mentioned" in the Company Flight Manual and General Operations Manual. She also stated that she had experienced the stall warning horn activation twice before during takeoff. Each of these resulted in continued flight. The FO's base of operation with Mesa was Boston. AIRCRAFT INFORMATION The airplane was equipped with two Pratt & Whitney Canada Inc., PT6A-67D, engines. Each engine was equipped with propellers manufactured by the Hartzell Propeller Inc., Piqua, Ohio. Each propeller assembly consisted of 4 composite material propeller blades, and both the left and right hub and blade assemblies had accumulated about 3,564 hours. A review of the airplane's maintenance records did not reveal any repetitive discrepancies related to the engines, propellers, anti-icing, flight controls or stall warning systems. AERODROME CONDITIONS The Bangor International Airport (BGR) had a concrete runway, 15-33, which was 11,439 feet long, 300 feet wide, and was grooved. According to the BGR airfield maintenance supervisor on duty at the time of the accident, the BGR snow removal crews had been plowing runway 15-33, from east to west. At 0815, the FAA BGR air traffic control tower (ATCT) advised the plow crews to clear the runway, due to a Boeing 727 that was to depart in 5 minutes. The plow crews were clear of the runway, at 0855. The maintenance supervisor stated that at that time, runway 15-33 had been plowed 150 feet east, and 75 feet west of the centerline. The supervisor reported that the plowed area was covered with a light dusting of snow less than 1/4 inch high, and braking action was "fair." He also reported that the piles of snow, which were the result of wind drifts and snow plowing, were about 1 foot high and 10 feet wide. A Notice to Airmen (NOTAM) was issued by the FAA, at 0830, which described runway 15-33 as "patchy thin layer of loose snow, braking action - fair." At 0840, BGR issued a field condition report which stated, " RWY 15/33 - plowed 150 feet east of centerline and 75 feet west of centerline full length. Light dusting of snow. Braking fair. Snow removal in progress." According to the BGR Operations Manager, the 0840 field condition report was not relayed to the FAA Flight Service Station because the airfield maintenance supervisor was waiting to finish plowing the runway. Winds were reported to be from 050 degrees at 10 knots. Prior to the arrival of the Safety Board, the first 8,000 feet of runway 33 was plowed to its full width of 300 feet, from the approach end toward the accident site. The airport management reported that they received approval to perform the plowing from an unidentified Federal Aviation Administration person after the accident. The airport authority reported that measurements were taken before the snow plowing continued. The airplane's landing gear tracks indicated that the airplane touched down 7,200 feet from the approach end of runway 33. They also measured the right main landing gear touch down point to be about 35 feet to the left of the runway centerline. The Safety Board measured the runway heading to be 339 degrees magnetic. Safety Board measurements also revealed that the runway was plowed approximately 55 feet to the west of the runway centerline. The main landing gear of the Beech 1900D, as published in the Pilot's Operating Manual, was 18 feet 4 inches wide from outside wheel edge to outside wheel edge. The airplane's left main landing gear exited the plowed portion of the runway at 7,802 feet, on a ground track of 329 degrees magnetic. The airplane's left main gear traveled approximately 90 feet left of the runway centerline, before returning to the plowed runway at 8,621 feet, on a ground track of 348 degrees magnetic. While traveling through the snow, the airplane's nose rotated to the right. The center of the airplane's fuselage came to a stop about 8,796 feet from the approach end of runway 33, on a magnetic heading of approximately 060 degrees. Examination of the wreckage and runway, about 2200, the evening of January 10, 1997, revealed that the runway was covered with frozen precipitation. The runway was also observed to be sloped downward from the centerline, toward the outer edges of each side of the runway. When a Safety Board investigator placed a hard surfaced clip board on the left side of the runway centerline, the clip board slid to the snow bank, 55 feet left of the centerline. FLIGHT RECORDERS Cockpit Voice Recorder The airplane was equipped with a Fairchild model A-100A cockpit voice recorder (CVR). The CVR was transported to the NTSB, Office of Research and Engineering, on January 10, 1997. The CVR committee convened on January 21, 1997, and a transcript was prepared of the entire 32:22 minute recording. According to the CVR Group Chairman's report, examination of the CVR's four channels revealed that ATC and other radio transmissions, to and from the airplane, were recorded at very low levels and were, "difficult or impossible to hear except for the mike clicks at the beginning of each transmission." Flight Data Recorder The airplane was equipped with a Fairchild model F1000 solid state flight data recorder (FDR). The FDR was transported to the NTSB Office of Research and Engineering on January 10, 1997, and a successful readout was completed. The NTSB Specialist's report contained takeoff data for the previous takeoff from Boston, and the accident flight. A review of the data revealed: Engine Power - The data from the previous successful takeoff from Boston, depicted symmetrical acceleration of both engines to takeoff torque, over approximately 10 to 12 seconds. The accident takeoff data also depicted symmetrical acceleration of both engines to takeoff torque, in approximately 12 seconds. Propeller RPM - The previous takeoff data revealed symmetrical acceleration of both propellers to approximately 1,700 RPM, in about 5 seconds. The accident flight data depicted symmetrical acceleration of both propellers to 1,678 RPM, in approximately 4 seconds Pitch Control Input - The previous takeoff data revealed that pitch control traveled from minus 15 degrees, to a maximum positive control input of 7 degrees. This was reduced to 5 degrees over a 5 second period. The accident takeoff data depicted the pitch control traveled from minus 15 degrees, to a maximum positive control input of 6.3 degrees. This was reduced to 1.5 degrees, 1 second later. An additional second later, the pitch control input was increased to 3.24 degrees, followed by a reduction to 0.92 degrees after another second. During the pitch control inputs, the airplane's pitch attitude increased to a maximum of 7.7 degrees, and was reduced to between 4 and 5 degrees over the next 4 seconds, until power was reduced and the climb aborted. Airspeed - During the Boston takeoff, the airplane's airspeed accelerated from zero to approximately 125 knots, in about 20 seconds. The accident takeoff data depicted an acceleration to 125 knots, in approximately 21 seconds. The accident airplane's airspeed was about 119 knots, at the maximum pitch up attitude of 7.7 degrees, and the indicated airspeed was 132.83 knots when the power was reduced, and the takeoff climb was aborted. WRECKAGE AND IMPACT INFORMATION The wreckage was examined on the runway by the Safety Board, the evening of January 10, 1997. About 12 hours had elapsed from the time of the accident, until the Safety Board began their observations. During that time, a thin coating of snow had fallen on the airplane. After photographs and initial documentation were completed, the airplane was moved to a hangar. Examination of the wreckage continued in a hangar at BGR, on January 11 and 12, 1997. The examination revealed that all components of the airplane were accounted for, except for the eight propeller blades, which were not attached to their respective hubs, and the nose wheel and strut. The 4 left engine propeller blades were separated from their propeller hub, and located between 205 and 475 feet, left of the runway center line. The four blades were intact, not damaged on the leading edges, and did not have chord wise scratches. The 4 right engine propeller blades were also separated from their propeller hub, and located between 91 and 175 feet left of the runway center line. One of the four blades displayed about 6 inches of broken material on the trailing edge of the blade, near the hub attachment point, and some scoring near the blade tip. The other three blades displayed impact damage along their trailing edges, and chord wise scratches on both sides of the blades. Each of the three blade tips were missing several inches. One of the three blades was broken chord wise in two pieces. White paint marks were observed on all four blades, similar to the white paint on the airplane's fuselage. The airplane's fuselage contained a jagged opening between 4 and 10 inches wide. The opening extended from the water line (WL) 100.00, upward to the top of the fuselage cabin. The forward edge of the opening was abeam the rear of the first row passenger seat, 1F, and the rear edge was just forw
The inadequate flight and winter operations training provided by the operator, and the pilot's improper decision to abort the takeoff while airborne above V1, due to a false stall warning horn. Also casual was the airport operations improper decision to discontinue plowing, and their failure to remove a snow pile on the runway. Factors relating to the accident were an easterly crosswind, the narrow icy runway conditions, inadequate FAA oversight in allowing the operator to continue operations with an inadequate training program that continued over several years, and the manufacturer's checklist which delayed the activation of the stall vane heat until just prior to takeoff.
Source: NTSB Aviation Accident Database
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