Landing (descent or approach)

On the afternoon of 13 October 2011, an Airlines PNG Bombardier DHC-8-103, registered P2-MCJ (MCJ), was conducting a regular public transport flight from Nadzab, Morobe Province, to Madang, Madang Province under the Instrument Flight Rules (IFR). On board the aircraft were two flight crew, a flight attendant, and 29 passengers. Earlier in the afternoon, the same crew had flown MCJ from Port Moresby to Nadzab. The autopilot could not be used because the yaw damper was unserviceable so the aircraft had to be hand-flown by the pilots. At Nadzab, the aircraft was refuelled with sufficient fuel for the flight to Madang and a planned subsequent flight from Madang to Port Moresby. MCJ departed Nadzab at 1647 LMT with the Pilot-in-Command as the handling pilot. The aircraft climbed to 16,000 ft with an estimated arrival time at Madang of 1717. Once in the cruise, the flight crew diverted right of the flight planned track to avoid thunderstorms and cloud. The Pilot-in-Command reported that communications between Madang Tower and an aircraft in the vicinity of Madang indicated a storm was approaching the aerodrome. He recalled that he had intended to descend below the cloud in order to be able to see across the sea to Madang and had been concentrating on manoeuvring the aircraft to remain clear of thunderstorms and cloud, so he had been looking mainly outside the cockpit. Because of the storm in the vicinity of the airport, he said there had been „some urgency‟ to descend beneath the cloud base to position for a right base for runway 07 at Madang, the anticipated approach. On this route, the descent to Madang was steep (because of the need to remain above the Finisterre Ranges until close to Madang) and, although the aircraft was descending steeply, the propellers were at their cruise setting of 900 revolutions per minute (RPM). Neither pilot noticed the airspeed increasing towards the maximum operating speed (VMO); the Pilot-in-Command reported afterwards that he had been „distracted‟ by the weather. When the aircraft reached VMO as it passed through 10,500 ft, with a rate of descent between 3,500 and 4,200 ft per minute, and the propellers set at 900 RPM, the VMO overspeed warning sounded. The Pilot-in-command reported that he had been about to ask the First Officer to increase the propeller speed to 1,050 RPM to slow the aircraft when this occurred. He raised the nose of the aircraft in response to the warning and this reduced the rate of descent to about 2,000 ft per minute, however, the VMO overspeed warning continued. The First Officer recalled the Pilot-in-Command moved the power levers back „quite quickly‟. Shortly after the power levers had been moved back, both propellers oversped simultaneously, exceeding their maximum permitted speed of 1,200 RPM by over 60 % and seriously damaging the left hand engine and rendering both engines unusable. Villagers on the ground reported hearing a loud „bang‟ as the aircraft passed overhead. The noise in the cockpit was deafening, rendering communication between the pilots extremely difficult, and internal damage to the engines caused smoke to enter the cockpit and cabin through the bleed air and air conditioning systems. The emergency caught both pilots by surprise. There was confusion and shock on the flight deck, a situation compounded by the extremely loud noise from the overspeeding propellers. About four seconds after the double propeller overspeed began, the beta warning horn started to sound intermittently, although the pilots stated afterwards they did not hear it. The left propeller RPM reduced to 900 RPM (in the governing range) after about 10 seconds. It remained in the governing range for about 5 seconds before overspeeding again for about 15 seconds, then returned to the governing range. During this second overspeed of the left propeller, the left engine high speed compressor increased above 110 % NH, becoming severely damaged in the process. About 3 seconds after the left propeller began overspeeding for the second time, the right propeller went into uncommanded feather due to a propeller control unit (PCU) beta switch malfunction, while the right engine was still running at flight idle (75% NH). Nine seconds after the double propeller overspeed event began, the Pilot-in-command shouted to the First Officer „what have we done?‟ The First Officer replied there had been a double propeller overspeed. The Pilot-in-command then shouted a second and third time „what have we done?‟. The First Officer repeated that there was a double propeller overspeed and said that the right engine had shut down. The Pilot-in-Command shouted that he could not hear the First Officer, who – just as the left propeller began governing again and the overspeed noise subsided – repeated that the right engine had shut down and asked if the left engine was still working. The Pilot-in-command replied that it was not working. Both pilots then agreed that they had „nothing‟. At this point, about 40 seconds after the propeller overspeed event began, the left propeller was windmilling and the left engine was no longer producing any power because of the damage caused to it by the overspeed. The right engine was operating at flight idle, although the propeller could not be unfeathered and therefore could not produce any thrust. On the order of the Pilot-in-Command, the First Officer made a mayday call to Madang Tower and gave the aircraft's GPS position; he remained in a radio exchange with Madang Tower for 63 seconds. The flight crew did not conduct emergency checklists and procedures. Instead, their attention turned to where they were going to make a forced landing. The aircraft descended at a high rate of descent, with the windmilling left propeller creating extra drag. The asymmetry between the windmilling left propeller and the feathered right propeller made the aircraft difficult to control. The average rate of descent between the onset of the emergency and arrival at the crash site was 2,500 ft per minute and at one point exceeded 6,000 ft per minute, and the VMO overspeed warning sounded again. During his long radio exchange with Madang Tower, the First Officer had said that they would ditch the aircraft, although, after a brief discussion, the Pilot-in-command subsequently decided to make a forced landing in the mouth of the Guabe River. The First Officer asked the Pilot-in-command if he should shut both engines down and the Pilot-in-command replied that he should shut „everything‟ down. Approximately 800 feet above ground level and 72 seconds before impact, the left propeller was feathered and both engines were shut down. The Pilot-in-Command reported afterwards that he ultimately decided to land beside the river instead of in the river bed because the river bed contained large boulders. The area chosen beside the river bed also contained boulders beneath the vegetation, but they were not readily visible from the air. He recalled afterwards that he overshot the area he had originally been aiming for. The aircraft impacted terrain at 114 knots with the flaps and the landing gear retracted. The Flight Attendant, who was facing the rear of the aircraft, reported that the tail impacted first. During the impact sequence, the left wing and tail became detached. The wreckage came to rest 300 metres from the initial impact point and was consumed by a fuel-fed fire. The front of the aircraft fractured behind the cockpit and rotated through 180 degrees, so that it was inverted when it came to rest. Of the 32 occupants of the aircraft only the two pilots, the flight attendant, and one passenger survived by escaping from the wreckage before it was destroyed by fire.

The airplane, registered to SV Leasing Company of Florida, operated by SOCATA North America, Inc., sustained substantial damage during a forced landing on a highway near Hollywood, Florida, following total loss of engine power. Visual meteorological conditions prevailed at the time and an instrument flight rules (IFR) flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 maintenance test flight from North Perry Airport (HWO), Hollywood, Florida. The airline transport pilot and pilot-rated other crew member sustained minor injuries; there were no ground injuries. The flight originated from HWO about 1216. The purpose of the flight was a maintenance test flight following a 600 hour and annual inspection. According to the right front seat occupant, in anticipation of the flight, he checked the fuel load by applying electrical power and noted the G1000 indicated the left fuel tank had approximately 36 gallons while the right fuel tank had approximately 108 gallons. In an effort to balance the fuel load with the indication of the right fuel tank, he added 72.4 gallons of fuel to the left fuel tank. At the start of the data recorded by the G1000 for the accident flight, the recorded capacity in the left fuel tank was approximately 105 gallons while the amount in the right fuel tank was approximately 108 gallons. The PIC reported that because of the fuel load on-board, he could not see the level of fuel in the tanks; therefore, he did not visually check the fuel tanks. By cockpit indication, the left tank had approximately 105 gallons and the right tank had approximately 108 gallons. The flight departed HWO, but he could not recall the fuel selector position beneath the thrust lever quadrant. He further stated that the fuel selector switch on the overhead panel was in the "auto" position. After takeoff, the flight climbed to flight level (FL) 280, and levelled off at that altitude about 20 minutes after takeoff. While at that altitude they received a "Fuel Low R" amber warning CAS message on the G1000. He checked the right fuel gauge which indicated 98 gallons, and confirmed that the fuel selector automatically switched to the left tank. After about 10 seconds the amber warning CAS message went out. He attributed the annunciation to be associated with a failure or malfunction of the sensor, and told the mechanic to write this issue down so it could be replaced after the flight. The flight continued and they received an amber warning CAS message, "Fuel Unbalance" which the right fuel tank had more fuel so he switched the fuel selector to supply fuel from the right tank to the engine. The G1000 indicates they remained at that altitude for approximately 8 minutes. He then initiated a quick descent to 10,000 feet mean sea level (msl) and during the descent accelerated to Vmo to test the aural warning horn. They descended to and maintained 10,000 feet msl for about 15 minutes and at an unknown time, they received an amber warning CAS message "Fuel Low R." Once again he checked the right fuel gauge which indicated it had 92 gallons and confirmed that the fuel tank selector automatically switched to the left tank. After about 10 seconds the CAS message went out. Either just before or during descent to 4,000 feet, they received an amber CAS message "Fuel Unbalance." Because the right fuel gauge indicated the fullest tank was the right tank, he switched the fuel selector to supply fuel to the engine from the right tank. The flight proceeded to the Opa-Locka Executive Airport, where he executed an ILS approach which terminated with a low approach. The pilot cancelled the IFR clearance and proceeded VFR towards HWO. While in contact with the HWO air traffic control tower, the flight was cleared to join the left downwind for runway 27L. Upon entering the downwind leg they received another amber CAS message "Fuel Unbalance" and at this time the left fuel gauge indicated 55 gallons while the right fuel gauge indicated 74 gallons. Because he intended on landing within a few minutes, he put the fuel selector to the manual position and switched to the fullest (right) tank. Established on final approach to runway 27L at HWO with the gear down, flaps set to landing, and minimum speed requested by air traffic for separation (85 knots indicated airspeed). When the flight was at 800 feet, the red warning CAS message "Fuel Press" illuminated and the right seat occupant with his permission moved the auxiliary fuel boost pump switch from "Auto" to "On" while he, PIC manually moved the fuel selector to the left tank. In an effort to restore engine power he pushed the power lever and used the manual over-ride but with no change. Assured that the engine had quit, he put the condition lever to cutoff, the starter switch on, and then the condition lever to "Hi-Idle" attempting to perform an airstart. At 1332:42, a flight crew member of the airplane advised the HWO ATCT, "…just lost the engine"; however, the controller did not reply. The PIC stated that he looked to his left and noticed a clear area on part of the turnpike, so he banked left, and in anticipation of the forced landing, placed the power lever to idle, the condition lever to cutoff, the fuel tank selector to off, and put the electrical gang bar down to secure the airplane's electrical system. He elected to retract the landing gear in an effort to shorten the landing distance. The right front seat occupant reported that the airplane was landed in a southerly direction in the northbound lanes of the Florida Turnpike. There were no ground injuries.

The aircraft was performing a regular schedule flight from Libreville to Port Gentil. The approach was completed in poor weather conditions with low visibility (1,000 metres) due to heavy rain falls. After touchdown, the aircraft did not decelerate as expected, skidded on runway, overran and came to rest down a slight embankment in shallow water. Both engines caught fire and both wings were partially torn off. All 30 occupants evacuated safely while the aircraft was damaged beyond repair. A thunderstorm was passing over the area at the time of the accident.

Following an uneventful flight from Karlsruhe-Baden-Baden, the crew started the descent to Antalya Airport runway 18C and completed the landing checklist. After touchdown, the aircraft started to vibrate and deviated to the right. Suddenly, the right main gear collapsed , causing the right engine nacelle to struck the ground. Metal rub the ground and a fire erupted in the right main wheel well. The aircraft eventually came to a complete stop, slightly to the right of the centerline. All 162 occupants evacuated safely while the aircraft was damaged beyond repair.

The aircraft departed Belo Horizonte-Pampulha on an executive flight to Manhuaçu, carrying two pilots and three passengers, among them the Brazilian singer Eduardo Costa. Following an uneventful flight, the crew started the descent to Manhuaçu-Elias Breder Airport. After touchdown on runway 02, the crew activated the reverse thrust systems but the aircraft did not decelerate as expected. So the crew started to brake when the tires burst. Unable to stop within the remaining distance, the aircraft overran, lost its undercarriage, collided with a fence and came to rest. There was no fire. All five occupants were rescued. Nevertheless, Eduardo Costa broke his nose and right hand during the accident.

About the time of departure, the wind at the departure airport was reported to be from 330 degrees at 13 knots with gusts to 22 knots. The pilot departed with an adequate supply of fuel for the intended 15-minute cargo flight to a nearby island. He entered a left traffic pattern to runway 36 at the destination airport and turned onto final approach with 30 degrees of flaps extended. Witnesses on the island reported that, about this time, a sudden wind gust from the west occurred. A witness (a fisherman by trade) at the airport estimated the wind direction was down the runway at 35 to 40 knots, with slightly higher wind gusts. After the sudden wind gust, he noted the airplane suddenly bank to the right about 80 degrees and begin descending. It impacted trees and powerlines then the ground. The same witness reported the engine sound was steady during the entire approach and at no time did he hear the engine falter. About 30 minutes before the accident, a weather observing station located about 6 nautical miles south-southeast of the accident site indicated the wind from the north-northwest at 24 knots, with gusts to 27 knots. About 30 minutes after the accident, the station indicated the wind from the northwest at 30 knots, with gusts to 37 knots. Postaccident examination of the airplane, its systems, and engine revealed no evidence of preimpact failures or malfunctions that would have precluded normal operation. The evidence is consistent with the airplane’s encounter with a gusty crosswind that led to the airplane’s right bank and the pilot’s loss of control, resulting in an accelerated stall.

Following an uneventful flight from Khartoum, the crew started the descent to Malakal, completed the checklist and lowered the landing gear. A technical problem occurred with the left main gear that remained stuck in its wheel well and failed to deploy. The crew decided to return to Khartoum. On approach to Khartoum-Haj Yusuf Airport runway 18, the crew elected to lower the gear manually but without success. The aircraft landed with both nose and right main gear deployed. After touchdown, the left wing contacted the runway surface. The aircraft slid for about 1,350 metres then veered to the left and came to rest. All 45 occupants evacuated safely and the aircraft was later considered as damaged beyond repair.

The pilot stated that after landing, the nose landing gear collapsed. Examination of the airplane nose strut down-lock installation revealed that the strut on the right side of the nose landing gear trunnion was installed incorrectly; the strut installed on the right was a left-sided strut. Incorrect installation of the strut could result in the bearing pulling loose from the pin on the right side of the trunnion, which could allow the nose landing gear to collapse. A review of maintenance records revealed recent maintenance activity on the nose gear involving the strut. The design of the strut is common for the left and right. Both struts have the same base part number, and a distinguishing numerical suffix is added for left side and right side strut determination. If correctly installed, the numbers should be oriented facing outboard. The original MU-2 Maintenance Manual did not address the installation or correct orientation of the strut. The manufacturer issued MU-2 Service Bulletin (SB) No. 200B, dated June 24, 1994, to address the orientation and adjustment. Service Bulletin 200B states on page 8 of 10 that the “Part Number may be visible in this (the) area from the out board sides (Inked P/N may be faded out).”

The aircraft departed Caracas-Maiquetía-Simón Bolívar Airport on a schedule service to Puerto Ordaz, carrying 125 passengers and a crew of 5. On this flight, the copilot was the PIC with the captain acting as instructor and a second copilot who was seating in the jump seat and acting as an observer. During the takeoff roll from Caracas Airport, the liftoff was completed quickly, causing the base of the empennage to struck the runway surface (tail strike). Nevertheless, the captain decided to proceed to Puerto Ordaz. On final to Puerto Ordaz, the approach speed was too low (123,8 knots). The aircraft sank and landed hard, causing the fuselage to be bent at the aft cabin, just prior to the tail, and both engine pylons to fail and to break from the fuselage. The aircraft was brought to a stop on the main runway and all 130 occupants evacuated safely.

The aircraft was performing a special flight with tourists above the Himalayan mountains and especially a tour of the Everest in the early morning. While returning to Kathmandu-Tribhuvan Airport, the copilot (PIC) was cleared to descend to 6,000 feet for a landing on runway 02. In marginal weather conditions, he passed below 6,000 feet until the aircraft contacted trees and crashed in hilly and wooded terrain located near the village of Bishanku Narayan, some 6,7 km southeast of the airport. The aircraft was destroyed by impact forces and a post crash fire. A passenger was seriously injured while 18 other occupants were killed. Few hours later, the only survivor died from his injuries. The 16 tourists were respectively 10 Indians, 2 Americans, 1 Japanese and 3 Nepalese.