Aviation Accident Summaries

Aviation Accident Summary NYC00MA201

LINNEUS, ME, USA

Aircraft #1

CGNAK

Grumman G-159

Analysis

The airplane was in cruise flight at 16,000 feet, in instrument meteorological conditions. About two minutes after the crew ceased cross-feeding due to a fuel imbalance, the left engine experienced a total loss of power. About one minute later, the co-pilot indicated to the pilot-in-command (PIC) that the airplane was losing airspeed, and about 15 seconds later, the co-pilot remarked "keep it up, keep it up." Shortly thereafter, the airplane departed controlled flight and impacted terrain. The airplane was destroyed by fire and impact forces. Examination of the left engine revealed no evidence of any pre-impact failures that would have accounted for an uncommanded in-flight shut-down. A SIGMET for potential severe clear icing was effective for airplane's flight path; however, the flight crew did not report or discuss any weather related problems around the time of the accident. At the time of the accident, the airplane was above its single-engine service ceiling. The PIC had accumulated approximately 6,000 hours of total flight experience, of which, about 500 hours were as PIC in make and model. The co-pilot had approximately 600 hours of total fight experience, of which, 300 hours were in make and model.

Factual Information

HISTORY OF FLIGHT On July 19, 2000, about 0031 eastern daylight Time (EDT), a Grumman G-159 (G-1), Canadian registry C-GNAK, operated by Airwave Transport as flight 9807, was destroyed when it impacted terrain in Linneus, Maine. The Canadian certificated airline transport pilot-in-command (PIC) and the commercial rated co-pilot were fatally injured. Night instrument meteorological conditions prevailed and an instrument flight rules flight plan had been filed for the flight that departed the Moncton Airport (CYQM), Moncton, New Brunswick, Canada, destined for Dorval International Airport (CYUL), Montreal, Quebec, Canada. The flight was conducted under Canadian Aviation Regulation (CAR) 704 as a scheduled courier flight. According to a Moncton Air Traffic Control (ATC) transcript, the flight departed CYQM, about 2348. Approximately 0005, the flight crew provided the following pilot report (PIREP): "OK we're now 50 miles west going through 10,000 feet ah we've got a good ride now looks like we're well past it ah there was some pretty good icing around 9,000 feet between 40 DME and 50 DME from Moncton and pretty heavy rain but ah nothing on the airway...no thunderstorms that is." They further described the icing as "moderate to severe between nine and ten thousand but it uh only lasted for about five minutes." The airplane leveled at 14,000 feet msl, and at 0015:15, the flight crew requested and received a "block" altitude clearance between 14,000 and 15,000 feet msl, because they were "sitting on the tops." The flight was instructed to contact the Boston Air Route Traffic Control Center (ARTCC) at 0016:06. According to a Federal Aviation Administration (FAA) transcript, the flight crew made initial contact with the Boston ARTCC at 0017:54. Additionally, they requested and received "direct dorval." At 0025:16, the flight crew requested to climb to 16,000 feet, and was subsequently cleared to maintain the "block" altitude, up to 16,000 feet. At 0029:56, the flight crew declared an emergency, requested vectors for the nearest airport and stated, "cannot maintain altitude." At 0030:10, the flight crew stated that they had "lost control." There were no further known communications with the airplane. Witnesses near the accident site reported being awakened by the loud sound of an airplane overhead. They described the sound as "surging," or "struggling" and one witness stated the noise repeatedly changed "like [the airplane] was getting closer then further." Witnesses then described hearing a loud explosion. The accident occurred during the hours of night approximately 46 degrees, 7 minutes north latitude, and 67 degrees, 48 minutes west longitude. PERSONNEL INFORMATION The PIC was the owner and president of the company that operated the airplane. He held a Canadian airline transport pilot certificate, with ratings for single and multi-engine land airplanes. He was also certified for Group I instrument privileges. Additionally, the PIC was type rated in G-1, C-550, and Boeing 727 airplanes. The PIC received his initial training for the G-1, in September 1995. The company reported he had accumulated approximately 6,000 hours of total flight experience, of which, about 500 hours were as PIC in the G-1. Additionally, he accumulated about 26 and 49 hours of flight experience in the G-1, during the 30 and 90 days prior to the accident, respectively. The PIC completed a G-1 Recurrent Course at Flight Safety International, Savannah, Georgia, on October 16, 1999. Additionally, he received a pilot proficiency check (PPC), on October 16, 1999. The PIC held a current Category I Canadian Medical Certificate, which was issued on April 3, 2000. The PIC also held an aircraft maintenance engineers certificate with ratings for the Convair 580, Convair 640, and the G-1. The co-pilot was hired on May 1, 1999, as a dispatcher, and began to transition to the G-1 in November 1999. He held a Canadian commercial pilot certificate, with ratings for single and multi-engine land airplanes. He was also certified for Group I instrument privileges and held a G-1 type rating. The company reported that the co-pilot had accumulated approximately 600 hours of total fight experience, of which, 300 hours were in make and model. He accumulated about 39 and 86 hours of flight experience in the G-1, during the 30 and 90 days prior to the accident, respectively. The co-pilot completed a G-1 Initial Training Course at Flight Safety International, Savannah, Georgia, on December 10, 1999. He received a PPC on January 14, 2000. The co-pilot held a current Category I Canadian Medical Certificate, which was issued on November 26, 1999. AIRCRAFT INFORMATION Review of the airplane maintenance records revealed that Airwave Transport purchased the accident airplane from North American Airlines, Ltd., Calgary, Alberta, Canada, in November 1999. On November 6, 1999, the airplane was flown for 4.5 hours from the Calgary International Airport, Calgary, Alberta, Canada, to Toronto. Prior to that flight, the airplane's most recent flight was conducted on July 17, 1998. The airplane was maintained by Airwave Transport under an approved manufacturer inspection program, and was most recently inspected on July 10, 2000. The airplane had an accumulated total airframe time of 22,046.7 hours, and 15,452 cycles. The accident airplane was equipped with two Rolls-Royce Dart 529-8X model turbo-propeller engines and two Dowty CR184-4-30-4-50 model propellers. The left engine and right engines were installed on the accident airplane on July 18, 1990, and May 6, 1997, respectively. The propellers were installed on the left and right accident engines on June 1, 2000, and April 21, 1998, respectively. At the time of the accident, the left engine and right engine had accumulated about 3,861 and 5,389 hours since overhaul, respectively. Review of the engine logbook records revealed an engine performance run was completed on July 7, 2000. No anomalies were reported on either engine. On July 11 and 15, 2000, the airplane was test flown by the PIC of the accident flight for 1 hour each. A company dispatch agent occupied the co-pilot seat during the July 15 test flight. The company dispatch agent stated that he held a commercial pilot's license and he had received 2-weeks of ground instruction and 5 hours of simulator training for the G-1. He did not hold a G-1 type rating. The dispatch agent stated that the test flight lasted about an hour and he did not observe any discrepancies with the airplane; nor did the PIC give any indication of any problems. Additionally, he recalled that the weather radar was tested and worked properly. The accident flight occurred during the third leg of the airplane's first courier trip. The accident flight crew departed Toronto, on July 17, 2000, and arrived Halifax, Nova Scotia, about 0300. Airwave Transport maintained an apartment in Halifax for flight crew personnel. The flight crew departed Halifax about 2145, and landed in Moncton about 2210. While in Halifax, the PIC informed company personnel that he had experienced no problems during the flight and was "very happy" with the airplane's performance. METEOROLOGICAL INFORMATION Prior to the flight, the accident flight crew received a weather-briefing package via fax, which included in-flight advisories, PIREPS, wind and temperature aloft forecasts, weather observations and forecasts for selected Canadian and U.S airports. A weather observation taken at the Houlton International Airport (HUL), Houlton, Maine, at 0049, reported: wind from 230 degrees at 5 knots, visibility 8 miles, ceiling 600 feet overcast, temperature and dew point 57 degrees Fahrenheit, altimeter 29.71 in/hg. A Safety Board Meteorology Factual Report was prepared for this accident. According to the Meteorologist's Factual Report, Geostationary Operational Environmental Satellite number 8 (GOES-8) data issued at 0015, depicted a low to mid-altitude overcast cloud layer over the Houlton area, and the accident site. The radiative temperatures in an approximately 50-mile area around Houlton corresponded to cloud heights, which ranged from 14,500 feet to 26,000 feet. The mean cloud top, and the cloud tops over the accident site were about 19,000 feet. The Canadian Meteorological Center (CMC) issued Gander (CYQX) SIGMET Bravo 6 at 0030, which was valid from 0035 to 0435. The SIGMET covered airspace, which included the airplane's flight path and the accident site. The SIGMET was issued for a broken line of cumulonimbus clouds with tops to 40,000 feet observed and forecast, with the potential for severe turbulence and severe clear icing. The line of thunderstorms was identified as moving eastward at 5 knots, with little change expected in intensity. There were no pilot reports over Maine for icing or turbulence recorded by the National Weather Service, between 2000 and 0400. According to interviews with company representatives, and former company pilots, it was normal procedure for a flight crew to obtain a "weather package" from company dispatch personnel. However, the flight crew was responsible for updating and obtaining any additional weather information, as needed through air traffic control and flight service stations. The company dispatcher's did not have any operational authority for the conduct of the flight, and the flight crew made all "go, no-go" decisions. FLIGHT RECORDERS The airplane was equipped with an L3 Communications cockpit voice recorder (CVR). The CVR was recovered from the accident site and forwarded to the Safety Board's Vehicle Recorders Division, Washington, DC. A CVR group convened on August 3, 2000, and a transcript of the entire 31:16 minute recording was prepared. Elapsed Times (ET) of the CVR transmissions were expressed in minutes and seconds from the beginning of the CVR recording; however, when compared to ATC transcripts, it was noted that the times expressed in the CVR transcript were about 30 seconds beyond EDT. At elapsed time 14:16, the co-pilot indicated he began to cross-feed fuel from the right fuel tank to correct a fuel imbalance. The cross feeding continued until about 27:11. At that time, the co-pilot stated "...turn that crossfeed off now...that all right with you?," and the PIC replied "yup." The following are excerpts from the CVR transcript: 29:16, A sound similar to decrease in propeller RPM 29:20, the co-pilot stated, "we got an engine failure, number one" 29:27, the PIC stated, "carry out the drill" 29:41, co-pilot stated, "feathered. RPM zero" 29:55, PIC stated, "what the # is going on?" 29:57, co-pilot stated, "I don't know." 30:07, PIC stated, "what is going on here." 30:09, co-pilot stated, "I don't know. # you're losing airspeed as well." 30:12, PIC stated, "ok. Declare an emergency." 30:25, co-pilot stated, "oh # keep it." 30:26, co-pilot stated, "keep it up. Keep it up." 30:36, PIC stated, "oh no, uh oh." 30:42, the co-pilot transmitted "we've lost control." 30:46, a sound similar to varying change in propeller noise begins and continues to the end of recording. 30:51, PIC stated, "uh ohh." 30:54, co-pilot stated, "which way are we flying?" 30:56, PIC stated, "I have no-" 30:56, co-pilot stated, "I don't know I don't know." 31:09, PIC stated, "I have no idea which way is up." 31:10, co-pilot stated, "oh. Ground... I don't know either []." 31:13, PIC stated, "*upside down?" No further conversation, or noises were recorded. WRECKAGE AND IMPACT INFORMATION The airplane's wreckage was found approximately 8 miles west HUL. An oval impact crater, which extended to 25 feet in diameter, was observed on the eastern side of the Meduxnekeag River. The depth of the crater was estimated to be approximately 5 feet deep. The banks of the river were lined with 60 to 70 foot tall trees. On the northeast rim of the crater, a small grouping of trees was uprooted and rested horizontal on a 020-degree heading. Several trees on the southern side of the crater were leaning away from the crater. None of the upper portions of the trees in the accident site area were damaged. The airplane was severely fragmented, and fire damaged. All major portions of the airplane were accounted for at the accident site. The majority of the wreckage was north and west of the crater, within 100 feet. Small and lightweight fragments of the airplane were found in all directions from the crater to a radius of approximately 500 feet. Standing fuel and oil were observed in the crater and leaching out of the ground into the river throughout the site. The right wing was at the southeast edge of the crater. The wing was severely fire damaged and the majority of the upper wing skin was consumed. Approximately 2 feet of the wing tip and spar cap was observed broken into several pieces, in close proximity. The majority of the wing leading edge was missing forward of the main spar. Chord wise compression buckling was observed on the lower and upper skin that was not consumed. The aileron and spring tab were present, but fractured in several pieces. The left wing was broken into several sections. The inboard portion of the wing was found approximately 30 feet southwest from the crater. The inboard wing section was severely fire damaged with the major portion of the upper and lower skin consumed. The wing leading edge forward of the main spar was not located. The upper and lower skin aft of the main spar exhibited signs of chord wise compression buckling. The wing tip was separated outboard of the flap actuator. The outboard portion of the wing was fragmented with its major portions found at 40 feet and 210 degrees, and 50 feet and 220 degrees from the crater. The right horizontal stabilizer was on the southwest side of the crater, attached to the vertical stabilizer and aft fuselage tail cone structure. The right horizontal stabilizer sustained severe impact and fire damage. The majority of the upper skin, outboard tip, and right elevator were consumed by fire. The lower skin and leading edge exhibited significant chord wise compression buckling. The left elevator trim tab was separated from the elevator in two pieces, and was located in the vicinity of the stabilizer. Additionally, the trim tab was severely fire damaged. The left horizontal stabilizer was separated from the empennage structure and also found in two pieces. A portion of the inboard stabilizer and elevator was located at 20 feet and 210 degrees from the crater. The leading edge was severely crushed and the upper and lower skin exhibited significant chord wise compression buckling. The outboard stabilizer and elevator were 30 feet and 225 degrees from the crater. The tip leading edge showed chord wise compression buckling with small fragments of wood lodged in the structure. The vertical stabilizer main spar was attached to the aft fuselage tail cone and empennage structure on the west side of the crater. The majority of the rudder and stabilizer was consumed by the post impact fire. Portions of the airplane's deicing boots remained attached to sections of each wing leading edge and both sides of the horizontal stabilizer leading edge. It could not be determined whether the boots were inflated or deflated at impact. None of the cockpit deice controls were recovered. All four trim actuators were recovered and their cables were observed in the middle position of their respective trim actuator drums. The airplane's ailerons, elevators, and rudder were manually controlled through cables, bell cranks and pushrods. The ailerons were mechanically boosted by spring tabs. The left aileron incorporated a manual trim tab. The rudder utilized a combination of mechanical spring tabs and manual trim. Portions of all control surfaces were located at the accident site; however, control system continuity could not be determined due to the severely fragmented nature of the wreckage. The cockpit area was destroyed by impact forces. Small fragments of the cockpit structure and instrument panels were located in the northern quadrant of the

Probable Cause and Findings

The pilot-in-command's failure to maintain minimum control airspeed, which resulted in a loss of control. Factors in this accident were clouds, and a loss of engine power for undetermined reasons, while in cruise flight above the airplane's single engine service ceiling.

 

Source: NTSB Aviation Accident Database

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