Landing (descent or approach)

At 0314, the pilot reported to the Air Traffic Control (ATC) Tower that he wanted to divert from his destination to land at a closer airport, and was cleared for a visual approach. At 0325, the pilot issued a "Mayday." On final approach the airplane struck a building and wires about 1/2 mile short of the runway. Witnesses that saw the airplane just before impact said that the airplane was low, there was no in-flight fire, and the engine sounds "...appeared to be a fluttering sound as if air [was] passing through the propeller." The pilot had filed for a cruise altitude of 15,000 feet, with a time en route of 5 hours, and fuel on board 6 hours. Weight and balance calculations showed that the pilot was operating about 722 pounds above the maximum gross weight for the takeoff, climb, and maximum cruise power settings. The Pilot Operating Handbook calculations showed that most of the fuel would have been used during the flight. The engine and propeller examinations revealed that both engines were not producing power at impact (windmilling). There were no discrepancies found with the engines or propellers. Examination of the propellers revealed that they were not in the feather position and they were not in beta/reverse position. Line personnel at the departure airport confirmed that all the tanks were topped off (282 gallons added). It took the flight 32 minutes to reach a cruise altitude of 15,000 feet, which calculated to about 293.3 pounds (1 gallon of Jet "A" equals 6.7 pounds), and a flight time of 4.9 hours from takeoff to impact. Sample calculations indicated that the fuel burn rate would have caused the airplane to use 2,649.3 pounds of Jet "A" turbine fuel during the flight. The flight departed with all tanks full 384 gallons usable (2,572.8 pounds), which calculates to insufficient fuel for the completion of the flight. Two gallons of fuel was drained from the right nacelle tank at the crash site, and there was no evidence of in-flight leakage. The sample calculations do not consider performance degradation for operating the airplane above the maximum allowable gross weight, which would cause the fuel consumption to go up because more power was required for the overweight conditions. The pilot's flight plan was for economy cruise, plus the airplane was over gross weight at takeoff, and there are no performance charts for that condition. So, the performance was even poorer than shown on the maximum power chart for climb and cruise. Calculations of the maximum allowable fuel that could be on board the aircraft showed that only 1851 pounds of turbine fuel could be carried to start the flight at the maximum allowable weight, or about 3.2 hours of flight. The en route winds aloft at the airplane's altitude indicated a slight tailwind for half the flight and a headwind of about 15 knots for the remainder of the flight.

The aircraft departed Lipa City Airport on a flight to Manila and should be delivered to Crown Cargo Express for several missions. On approach to Ninoy Aquino Airport, the crew informed ATC about engine problems. The captain attempted an emergency landing when the aircraft struck power cables and crashed in a rice paddy field located in Santa Rosa, about 25 km south of the airport. All nine occupants escaped uninjured while the aircraft was damaged beyond repair.

On approach to Turtkul Airport, the aircraft was not properly aligned on the glide and the captain initiated a go-around procedure. During a second attempt to land, the aircraft position was wrong so the pilot passed over the runway 20 at a height of about 4-7 metres then initiated a second go-around procedure. The aircraft passed over the runway end at a height of 10 metres when the landing gear were retracted. At a distance of 2 km past the runway end, the aircraft collided with trees and power cables, crash landed, slid for about 130 metres and came to rest against an embankment. Two passengers were killed while four others were injured.

As the MD-90 touched down following a 25-minute flight from Taipei, there was a loud noise from the front of the cabin and thick black smoke poured from one of the overhead luggage compartments on the right hand side of the plane. Insulation and charred luggage littered the runway. Passengers were swiftly evacuated, but it took firefighters more than half an hour to control the fire. Twenty-eight people were injured. Preliminary investigation reports in 1999 indicated that the blast was caused by two bottles of household bleach. However, the Hualien District Court judges decided the bottles contained gasoline. According to the judges, Ku Chin-shui had put the gasoline into two plastic bleach bottles and gave them to his nephew. The gasoline leaked during the flight and exploded when it caused a short-circuit in a motorbike battery in a nearby overhead luggage compartment. In July 2003 Ku appealed a seven-and-a-half-year prison term. Considering the prosecutor's case against Ku to be full of holes, the Supreme Court ordered a retrial.

China Airline’s flight CI642 was scheduled to operate from Bangkok to Taipei with an intermediate stop in Hong Kong. The crew had carried out the sector from Taipei to Bangkok, passing through Hong Kong on the previous day. On that flight, the crew were aware of the Severe Tropical Storm (STS) ‘Sam’ approaching Hong Kong and the possibility that it would be in the vicinity of Hong Kong at about the scheduled time of arrival on the following evening. Weather information provided at the preflight briefing for the return flight indicated the continuing presence of STS ‘Sam’ with its associated strong winds and heavy precipitation. The flight departed from Bangkok on schedule with 300 passengers and 15 crew on board, with an estimated time of arrival (ETA) of 1038 hour (hr) in Hong Kong. The commander had elected to carry sufficient fuel to permit a variety of options on arrival – to hold, to make an approach, or to divert. If an immediate approach was attempted, the aircraft would be close to its Maximum Landing Weight (MLW) involving, in consequence, a relatively high speed for the approach and landing. Throughout the initial stages of the flight and during the cruise, the commander was aware of the crosswind component to be expected in Hong Kong and reviewed the values of wind direction and speed which would bring it within the company’s crosswind limit as applicable to wet runways of 24 kt. In the latter stage of the cruise, the crew obtained information ‘Whisky’ from the Automatic Terminal Information Service (ATIS) timed at 0940 hr, which gave a mean surface wind of 320 degrees (º) / 30 knots (kt) maximum 45 kt in heavy rain, and a warning to expect significant windshear and severe turbulence on the approach. Although this gave a crosswind component of 26 kt which was in excess of the company’s wet runway limit of 24 kt, the commander was monitoring the gradual change in wind direction as the storm progressed, which indicated that the wind direction would possibly shift sufficiently to reduce the component and thus permit a landing. Hong Kong Area Radar Control issued a descent clearance to the aircraft at 1014 hr and, following receipt of ATIS information ‘X-ray’ one minute later, which included a mean surface wind of 300º at 35 kt, descent was commenced at 1017 hr. Copies of the information sheets used by Air Traffic Control (ATC) as the basis for ATIS broadcasts ‘Whisky’ and ‘X-ray’ are at Appendix 1. The approach briefing was initiated by the commander just after commencing descent. The briefing was given for an Instrument Landing System (ILS) approach to Runway 25 Right (RW 25R) at HKIA. However, the active runway, as confirmed by the ATIS was RW 25L. Despite the inclusion in the ATIS broadcasts of severe turbulence and possible windshear warnings, no mention was made in the briefing of the commander’s intentions relating to these weather phenomena nor for any course of action in the event that a landing could not be made, other than a cursory reference to the published missed approach procedure. The descent otherwise continued uneventfully and a routine handover was made at 1025 hr to Hong Kong Approach Control which instituted radar vectoring for an ILS approach to what the crew still believed was RW 25R. At 1036 hr, after having been vectored through the RW 25L localizer for spacing, CI642 was given a heading of 230º to intercept the localizer from the right and cleared for ILS to RW 25L. The co-pilot acknowledged the clearance for ILS 25L but queried the RVR (runway visual ranges); these were passed by the controller, the lowest being 1300 m at the touchdown point. The commander then quickly re-briefed the minimums and go-around procedure for RW 25L. At 1038 hr, about 14 nautical miles (nm) to touchdown, the aircraft was transferred to Hong Kong Tower and told to continue the approach. At 1041 hr, the crew were given a visibility at touchdown of 1600 metres (m) and touchdown wind of 320º at 25 kt gusting 33 kt, and cleared to land. The crew of flight CI642 followed China Airline’s standard procedures during the approach. Using the autoflight modes of the aircraft, involving full use of autopilot and autothrottle systems, the flight progressed along the ILS approach until 700 ft where the crew became visual with the runway and approach lights of RW 25L. Shortly after this point the commander disconnected the autopilot and flew the aircraft manually, leaving the autothrottle system engaged to control the aircraft’s speed. After autopilot disconnect, the aircraft continued to track the runway centreline but descended and stabilized slightly low (one dot) on the glideslope. Despite the gustiness of the wind, the flight continued relatively normally for the conditions until approximately 250 ft above the ground at which point the co-pilot noticed a significant decrease in indicated airspeed. Thrust was applied as the co-pilot called ‘Speed’ and, as a consequence, the indicated airspeed rose to a peak of 175 kt. In response to this speed in excess of the target approach speed, thrust was reduced and, in the process of accomplishing this, the aircraft passed the point (50 ft RA) at which the autothrottle system commands the thrust to idle for landing. Coincidentally with this, the speed decreased from 175 kt and the rate of descent began to increase in excess of the previous 750-800 feet per minute (fpm). Although an attempt was made to flare the aircraft, the high rate of descent was not arrested, resulting in an extremely hard impact with the runway in a slightly right wing down attitude (less than 4º), prior to the normal touchdown zone. The right mainwheels contacted the runway first, followed by the underside of the right engine cowling. The right main landing gear collapsed outward, causing damage to the right wing assembly, resulting in its failure. As the right wing separated, spilled fuel was ignited and the aircraft rolled inverted and came to rest upside-down alongside the runway facing in the direction of the approach. The cockpit crew were disorientated by the inverted position of the aircraft and found difficulty in locating the engine controls to carry out engine shut down drills. After extricating themselves, they went through the cockpit door into the cabin and exited the aircraft through L1 door and began helping passengers from the aircraft through a hole in the fuselage. Airport fire and rescue services were quickly on the scene, extinguishing the fuel fire and evacuating the passengers through the available aircraft exits and ruptures in the fuselage. As a result of the accident, two passengers were found dead on arrival at hospital, and six crew members and 45 passengers were seriously injured. One of the seriously injured passengers died five days later in hospital.

The single engine aircraft departed Niederstetten Airport, Baden-Wurttemberg, at 0915LT with two passengers and one pilot on board. The flight was completed under VFR mode until Würzburg then the pilot was cleared to continue under IFR mode to the destination. On approach to Paderborn-Lippstadt Airport, after passing 5,000 feet, the pilot was cleared for an ILS approach to runway 24. At an altitude of 3,700 feet, while trying to establish on the ILS, the pilot momentarily lost control of the airplane. He elected to regain control when the aircraft climbed to 4'000 feet, entered a left turn then an uncontrolled descent until it crashed in a field located in Borchen, about 8 km short of runway 24. The aircraft was destroyed and all three occupants were killed.

The pilot landed with the landing gear in the retracted position, when both the main and auxiliary hydraulic systems failed to extend the gear. The airplane caught fire as it skidded down the runway. The left inboard main tire had blown on takeoff and a 30-inch section of tread was loose. Black marks were along the length of the landing gear strut and up into the wheel well directly above the left inboard wheel. The normal and emergency hydraulic systems both connect to a common valve body on the landing gear actuator. This valve body also had black marks on it. A gap of 0.035 inch was measured between the valve body and actuator. When either the normal or auxiliary hydraulic system was pressurized, red fluid leaked from this gap. Examination revealed that one of two bolts holding the hydraulic control valve in place had fractured and separated. The fractured bolt experienced a shear load that was oriented along the longitudinal axis of the actuator in a plane consistent with impact forces from the flapping tire tread section.. Separation of only one bolt allowed the control valve to twist about the remaining bolt in response to the load along the actuator's longitudinal axis. This led to a loss of clamping force on that side of the actuator. Hydraulic line pressure lifted the control valve, which resulted in rupture of an o-ring that sealed the hydraulic fluid passage. 14 CFR 25.739 describes the requirement for protection of equipment in wheel wheels from the effects of tire debris. The revision of this regulation in effect at the time the airplane's type design was approved by the FAA requires that equipment and systems essential to safe operation of the airplane that is located in wheel wells must be protected by shields or other means from the damaging effects of a loose tire tread, unless it is shown that a loose tire tread cannot cause damage. Examination of the airplane and the FAA approved production drawings disclosed that no shields were installed to protect the hydraulic system components in the wheel well.

While enroute from Pueblo, Colorado, to Columbia, South Carolina, the captain's windshield delaminated, and the flight diverted to Fort Lauderdale, Florida, for repairs. The flight crew stated the first officer was flying the airplane and had been instructed by the captain to make a firm landing at Fort Lauderdale to get the airplanes weight on the wheels, due to the airplane being light. The landing was firm and the first officer activated the engine thrust reversers. As the nose landing gear touched down, the airplane began veering to the left. Attempts to control the veer to the left were unsuccessful and the airplane ran off the left side of the runway. The airplane then ran over a taxiway and collided with a taxiway sign and the concrete base for the sign. The nose landing gear collapsed and the airplane came to rest. Examination of the runway showed alternating dark and light marks from the left main landing gear tire were present on the runway about 160 feet before marks from the right main landing gear tire are present. Post accident examination of the airplanes landing gear, tires, wheels, bakes, spoilers, and engine thrust reversers, showed no evidence of pre-accident failure or malfunction. At the time of the accident the flight crew had been on duty for about 17 hours 45 minutes.

The airplane landed wheels up after the instructor pilot failed to lower the landing gear. The instructor told the student to execute 'a no flap landing due to a simulated hydraulic pump failure.' The student established the airplane on the approach and called for the 'Emergency Gear Extension Checklist.' The instructor delayed extending the gear in accordance with the operator's flight standards manual, which stated that the landing gear should not be extended until the landing was assured. Later in the approach, when the gear warning horn stopped sounding, due to the student's movement of the power levers forward, the instructor removed his hand from the gear handle without extending the gear. The instructor stated that 'because [the student] had already called for the [Emergency Gear Extension] checklist once before, in a split second thought process, [he] mistakenly thought it had been completed.' Following the accident, the landing gear system was tested and found to operate normally. Review of the maintenance records revealed no uncorrected discrepancies. At the time of the accident, the instructor pilot was completing a 9-hour work day, and did not have a lunch break.

Following a wrong approach configuration, the aircraft was too high on the glide and landed too far down the runway. After touchdown, it was unable to stop within the remaining distance, overran and came to rest 150 metres further. All five crew members escaped uninjured while the aircraft was damaged beyond repair. The crew completed the landing procedure with a tailwind component of nine knots.