Cargo

The airplane was operated as an on-demand cargo flight that impacted trees and terrain about one mile from the destination airport during a non-precision approach. Night instrument meteorological conditions prevailed at the time of the accident. The airplane was equipped with an "icing protection system" and a report by another airplane that flew the approach and landed without incident indicated that light rime icing was encountered during the approach. Radar data shows that the accident airplane flew the localizer course inbound and began a descent past the final approach fix. No mechanical anomalies that would have precluded normal operation were noted with the airplane.

After being offloaded at Kabul Airport following a flight from Bahrain, the four engine aircraft took off for a short flight to Bagram AFB, carrying a load of telecommunication equipments for the US Armed Forces. Few minutes after takeoff, the crew changed frequency and contacted Bagram Airbase. Due to traffic at Bagram, the crew was instructed to hold at 10,000 feet about 10 nm south of Bagram AFB. Shortly later, the crew started the descent in haze when the aircraft struck the slope of a mountain located near Kōh-e Khāk-e Shahīdān, about 28,6 km northwest of Kabul. The aircraft disintegrated on impact and all eight occupants were killed. At the time of the accident, the visibility was estimated to be 5 km with haze and clouds at 1,200 feet. The wreckage wasa found at an altitude of 2,120 metres.

According to the pilot, the airplane took off with a flaps setting of 25 percent, per the operator’s procedures at the time. He stated that, immediately after raising the landing gear after takeoff, he heard an explosion and saw that all gauges for the left engine, a Pratt & Whitney Canada (P&WC) PT6A-34, pointed to zero, indicating a loss of power to the left engine. He also noted that the left propeller had completely stopped so he added full power to the right engine, left the flaps at 25 percent, and left the landing gear up. He further stated that, although he “stood on the right rudder,” he could not stop the airplane’s left turning descent. The pilot later noted that, after the left engine lost power, he “couldn’t hold V speeds” and “the stall warning horn was going off the whole time.” Post accident examination of the accident airplane’s left engine revealed that that it had failed and that the propeller had been feathered. Examination of the trim positions revealed that the rudder was at neutral trim and the aileron was at full left trim. Although these trim positions could have been altered when the wings separated from the fuselage during ground impact, the pilot’s comment that he “stood on the rudder” suggests that he either had not trimmed the airplane after the engine failure or had applied trim opposite the desired direction. The activation of the stall warning horn and the pilot’s statement that he “couldn’t hold V speeds” indicate that he also did not lower the nose sufficiently to maintain best single-engine rate of climb or best single-engine angle of climb airspeed. In addition, a performance calculation conducted during the National Transportation Safety Board’s investigation revealed that the airplane, with flaps set at 25 degrees, would have been able to climb at more than 400 feet per minute if the pilot had maintained best single-engine rate of climb airspeed and if the airplane had been properly trimmed. Post accident examination of the accident airplane’s left engine revealed fatigue fracturing of the first-stage sun gear.[1] According to the airplane’s maintenance records, during an October 1998 engine overhaul, the first-stage planet gear assembly was replaced due to “frosted and pitted gear teeth.” The planet gear assembly’s mating sun gear was also examined during overhaul but was found to be serviceable and was reinstalled with the new planet gear assembly, which was an accepted practice at the time. However, since then, the engine manufacturer determined that if either the sun gear or planet gear assembly needed to be replaced with a zero-time component, the corresponding mating gear/assembly must also be replaced with a zero-time component; otherwise, the different wear patterns on the gears could potentially cause “distress” to one or both of the components. Review of maintenance records showed that the engines were maintained, in part, under a Federal Aviation Administration (FAA)-approved “on-condition” maintenance program;[2] Business Air’s maintenance program was approved in May 1995. In April 2002, P&WC, the engine manufacturer, issued Service Bulletin (SB) 1403 Revision 7, which no longer mentioned on-condition maintenance programs and required, for the first time for other time between overhaul extension options, the replacement of a number of PT6A-34, -35, and -36 life-limited engine components, including the first-stage sun gear at 12,000 hours total time since new. The first-stage sun gear on the accident airplane failed at 22,064.8 hours. In November 2005 (when the Manchester accident occurred), Business Air was operating under an engine on-condition maintenance program that did not incorporate the up-to-date PT6A 34, -35, and -36 reliability standards for the life-limited parts listed in SB 1403R7 because the SB did not address previously approved on-condition maintenance programs. Three months later, in an e-mail message to Business Air, P&WC stated that it would continue to “endorse” Business Air’s engine on-condition maintenance program. Although SB 1403R7 improves PT6A-34, -35, and -36 engine reliability standards, allowing grandfathered on condition maintenance programs for these engines is less restrictive and does not offer the same level of reliability. The National Transportation Safety Board’s review of maintenance records further revealed numerous deficiencies in Business Air’s on-condition engine maintenance program that appear to have gone undetected by the Portland, Maine, Flight Standards District Office (FSDO), which is in charge of monitoring Business Air’s operations. For example, one infraction was that Business Air did not specify which parts were included in its on-condition maintenance program and which would have been removed by other means, such as hard-time scheduling.[3] Also, the operator used engine condition trend monitoring as part of determining engine health; however, review of records revealed missing data, inaccurate data input, a lack of regular trend analyses, and a failure to update trends or reestablish baselines when certain maintenance was performed. Another example showed that, although Business Air had an engine-oil analysis program in place, the time it took to send samples for testing and receive results was lengthy. According to maintenance records, the operator took an oil sample from the accident engine more than 2 weeks before the accident and sent it for testing. The oil sample, which revealed increased iron levels, would have provided valuable information about the engine’s health. However, the results, which indicated a decline in engine health, were not received until days after the accident. If the FAA had been properly monitoring Business Air’s maintenance program, it may have been aware of the operator’s inadequate maintenance practices that allowed, among other things, an engine with a sun gear well beyond what the manufacturer considered to be a reliable operating timeframe to continue operation. It also took more than 2 1/2 years after the accident for the FAA to finally present a consent order[4] to the operator, in which both parties not only acknowledged the operator’s ongoing maintenance inadequacies but also the required corrective actions. [1] A sun gear is the center gear around which an engine’s planet gear assembly revolves; together, the sun gear and planet gear assembly provide a means of reducing the engine’s rpm to the propeller’s rpm. [2] According to FAA Advisory Circular (AC) 120-17A, “Maintenance Control by Reliability Methods,” under on-condition maintenance programs, components are required to be periodically inspected or checked against some appropriate physical standard to determine whether they can continue in service. [3] According to FAA AC 120-17A, “Maintenance Control by Reliability Methods,” under hard time maintenance programs, components are required to be periodically overhauled or be removed from service. [4] A consent order is a voluntary agreement worked out between two or more parties to a dispute. It generally has the same effect as a court order and can be enforced by the court if anyone does not comply with the orders. [4] A consent order is a voluntary agreement worked out between two or more parties to a dispute. It generally has the same effect as a court order and can be enforced by the court if anyone does not comply with the orders.

The aircraft was completing a cargo flight with various equipments on behalf of the Conader, the Commission Nationale de Désarmement et de Réinsertion. Following an uneventful flight, the crew started the approach in heavy rain falls. After landing on a wet runway, the aircraft was unable to stop within the remaining distance and overran. It lost its undercarriage and came to rest in marshy field. All three occupants escaped uninjured while the aircraft was damaged beyond repair. Aquaplaning suspected.

The twin engine aircraft departed Bergamo-Orio al Serio Airport on a night cargo service to Zagreb, carrying one passenger (the captain's wife), two pilots and a load of 1,600 kilos of small packages. After takeoff from runway 28, while climbing in foggy conditions, the aircraft entered a left turn then descended, collided with a powerline and crashed in an open field located one km north of the airfield. The aircraft disintegrated on impact and all three occupants were killed.

The airplane was fueled with 65-gallons of jet-A in preparation for the evening's flight. The 6,600-hour pilot stated that no abnormalities were noted during the engine start, and takeoff. However; shortly after departure, and after the pilot had leveled off at 7,000-feet, he reported to air traffic control that he had an engine failure and a total power loss. During the descent, the pilot attempted both an air and battery engine restart, but was not successful. The inspection on the engine was conducted on November 30, 2005. The accessory gearbox had a reddish-brown stain visible beneath the fuel pump/fuel control unit. The accessory gearbox was turned; rotation of the drive splines in the fuel pump (splines for the fuel control unit) was not observed. The fuel pump unit was then removed, the area between the fuel pump and accessory gearbox was stained with a reddish brown color. The fuel pump drive splines were worn. Additionally, the internal splines on the fuel pump drive coupling were worn. The wear on the spline drive and coupling prevented full engagement of the spline drives. Both pieces had evidence of fretting, with a reddish brown material present. The airplane had approximately 130 hours since a maintenance inspection (which included inspection of the fuel pump). The engine had accumulated approximately a total time of 9,852 hours, with 5,574 hours since overhaul.

On the day before the occurrence, the accident aircraft arrived in Winnipeg, Manitoba, on a flight from Thunder Bay, Ontario. The aircraft was parked in a heated hangar overnight and was pulled outside at about 0410 central daylight time. The pilot reviewed the weather information and completed planning for the flight, which was estimated to take two hours and six minutes. The aircraft was refuelled and taxied to Apron V at the Winnipeg International Airport, where it was loaded with cargo. After loading was complete, the pilot obtained an instrument flight rules (IFR) clearance for the flight to Thunder Bay, taxied to Runway 36, received take-off clearance, and departed. The aircraft climbed on runway heading for about one minute to an altitude of 1300 feet above sea level (asl), 500 feet above ground level (agl). The flight was cleared to 9000 feet asl direct to Thunder Bay, and the pilot turned on course. The aircraft continued to climb, reaching a maximum altitude of 2400 feet asl about 2.5 minutes after take-off. The aircraft then started a gradual descent averaging about 400 feet per minute (fpm) until it descended below radar coverage. The accident occurred during hours of darkness at 0543. The Winnipeg Fire Paramedic Service were notified and responded from a nearby station.

The twin-engine airplane was destroyed when it impacted an earthmoving scraper and terrain in a field about 2.5 miles north of the departure airport in night visual meteorological conditions. Witnesses reported that the pilot had aborted an earlier flight when he returned to the airport and told the mechanic that he had a right engine fire warning light. The discrepancy could not be duplicated during maintenance, and the airplane departed. About 23 minutes after departure, the pilot reported to air traffic control that he needed to return to the airport to have something checked out. The pilot did not report to anyone why he decided to return to the departure airport, and he flew over four airports when he returned to the departure airport. Radar track data indicated that the airplane flew over the departure end of runway 35 at an altitude of about 1,600 feet agl, and made a descending left turn. The airplane's altitude was about 800 feet agl when it crossed the final approach course for runway 35. The airplane continued the descending left turn, but instead of landing on runway 35, the airplane flew a course that paralleled the runway, about 0.8 nm to the right of runway 35. The airplane continued to fly a northerly heading and continued to descend. The radar track data indicated that the airplane's airspeed was decreasing from about 130 kts to about 110 kts during the last one minute and fifty seconds of flight. The last reinforced beacon return indicated that the airplane's altitude was about 200 feet agl, and the airspeed was about 107 kts. The airplane impacted terrain about 0.75 nm from the last radar contact on a 338-degree magnetic heading. A witness reported that the airplane was going slow and was "extremely low." He reported that the airplane disappeared, and then there was an explosion and a fireball that went up about 1,000 feet. Inspection of the airplane revealed that it impacted the earthmover in about a wings level attitude. The landing gear handle was found to be in the landing gear UP position. The inspection of the left engine and propeller revealed damage indicative of engine operation at the time of impact. Inspection of the right engine revealed damage indicative of the engine not operating at the time of impact, consistent with an engine shutdown and a feathered propeller. No pre-existing conditions were found in either engine that would have interfered with normal operation. The inspection of the right engine fire detection loop revealed that the connector had surface contamination. When tested, an intermittent signal was produced which could give a fire alarm indication to the pilot. After the surface contamination was removed, the fire warning detection loop operated normally.

The single engine airplane departed Kasese on a charter flight to Bukavu on behalf of the company Decilac, carrying one female passenger and two pilots. While cruising in poor weather conditions (heavy rain falls and strong winds), the aircraft crashed in a mountainous area located about 40 km east of Bukavu. The wreckage was found few hours later and the passenger was rescued while both pilots, an Armenian captain and a Congolese copilot, were killed. It was reported that the operator was not officially registered to the DRC Civil Aviation Authority and did not have any audit prior to start its operations.

On final approach to Isiro Airport, the crew encountered poor visibility due to fog. Too low, the aircraft collided with a palm tree and crashed 1,500 metres short of runway 31. All 11 occupants were killed.