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Report: Boeing 747-400 nearly hit the ground after descending below MDA at Tokyo-Haneda Airport
1 August 2020

Report: Boeing 747-400 nearly hit the ground after descending below MDA at Tokyo-Haneda Airport

Pilot decision-making in poor weather contributed to fatal CFIT accident in Canada

TSB Canada found that pilot decision-making was a factor in a fatal controlled flight into terrain accident involving a Cessna 208B in 2019 near Mayo, Yukon.

On 6 August 2019, a Cessna 208B Supervan 900 operated by Alkan Air was on a visual flight rules (VFR) flight from Rau Airstrip to Mayo Airport, Canada, with one pilot and one passenger on board. While enroute, the aircraft entered an area of low visibility and low cloud ceilings. The aircraft departed from the intended route, turned into a box canyon and struck rising terrain, fatally injuring the pilot and passenger. The aircraft was destroyed and there was a brief post-impact fire.

The investigation found that the pilot’s decision to continue a low altitude flight into poor weather conditions in mountainous terrain was influenced by several factors. The pilot had recently completed a flight along the same route, in similar weather conditions. The pilot’s decision-making would have been affected by his familiarity with the route and, consequently, he likely did not consider an alternate route to avoid the poor weather conditions.

The high speed at low altitude and low visibility reduced the opportunities for the pilot to take alternative action to avoid terrain. Within the box canyon, the canyon floor elevation increased abruptly within less than one nautical mile and the low visibility prevented the pilot from detecting this and taking sufficient actions to prevent a collision. Additionally, the aircraft’s terrain awareness and warning system aural alerts were ineffective in warning the pilot of the rising terrain because he had already heard multiple similar alerts in the preceding minutes of flight, or had silenced these alerts.

Following the occurrence, Alkan Air made changes to its Caravan operations, including requiring a second flight crew member for Cessna 208B Grand Caravan captains with less than 2000 hours. Before becoming a captain on the Caravan, candidates must perform as a second crew member on the Caravan for 1 season. The company has also made modifications to its emergency response plan.

Departure procedures misunderstanding contributed to serious loss of separation incident at Sydney Airport

Likely flight crew confusion with Sydney-centric departure procedures contributed to a Boeing 777 turning right instead of left on departure from Sydney Airport, resulting in a serious airprox incident with an ATR 72 which had taken off from the parallel runway, an ATSB investigation notes.

The United Airlines Boeing 777-300ER had departed from Sydney Airport’s runway 34L bound for San Francisco and was cleared to follow a standard instrument departure (SID) requiring the aircraft to maintain runway heading until reaching 1,500 feet, at which point the aircraft was required to turn left and track towards Richmond, northwest of Sydney. However, the 777 instead climbed straight ahead through 1,500 feet to about 2,100 feet and then turned to the right, resulting in a loss of separation with the Virgin Australia ATR aircraft, which had departed from the parallel runway (runway 34R).

The ATSB’s investigation found that in entering the cleared ‘RIC5’ standard instrument departure in the 777’s flight management computer (FMC), the aircraft captain, who was the pilot flying, closed (removed) a deliberate ‘discontinuity’ – or gap – in the waypoint sequence. This discontinuity was pre-programmed to represent where air traffic control was to provide radar vectors to transition from the SID to join the planned oceanic track to San Francisco.

In removing the discontinuity, likely due to the captain’s limited exposure to the assignment of varying Sydney-centric departure procedures, the aircraft was in effect programmed to track direct to a navigation waypoint (DIPSO), about 45 nautical miles to the east of Sydney, after reaching the initial waypoint at 1,500 feet. This resulted in the right turn and the subsequent loss of separation with the ATR 72.

Removing the discontinuity would have been appropriate for many procedural transitions, which are commonplace in the United States, the ATSB noted. The ATSB’s investigation also notes that the pilot flying probably did not effectively communicate the changes made to the FMC coding to the other members of the flight crew, after reprogramming the FMC from the anticipated simpler ‘SYD1’ standard instrument departure, which had been entered based on previous experience.

More information: ATSB report

Report: Insufficient fuel for flight resulted in forced landing of Beech 200 near Gillam, Canada

TSB Canada concluded that an unnoticed fuel shortage resulted in fuel exhaustion and a subsequent forced landing of a Beechcraft B200 medevac aircraft in April 2019.

On 24 April 2019, the Beechcraft B200, was on a positioning flight from Winnipeg/James Armstrong Richardson International Airport, Canada to station the aircraft at Rankin Inlet Airport, with a stop planned in Churchill. The captain was receiving line indoctrination training from the training pilot, who assumed the role of first officer during the flight. Two flight nurses were also on board.

While in cruise flight, the crew declared an emergency due to a fuel issue. The flight crew diverted to Gillam Airport and initiated an emergency descent. During the descent, the fuel supply was exhausted and both engines eventually lost power. The crew attempted a forced landing on runway 23, but instead touched down on the frozen surface of Stephens Lake, 750 feet short of the runway threshold. There were no injuries, although the aircraft sustained substantial damage.

The investigation found that the flight crew had multiple opportunities to identify the shortage of fuel on board the aircraft. Before takeoff, when the captain asked if the aircraft was ready for flight, the first officer replied that it was, not recalling that the aircraft required fuel. Then, while performing the Fuel Quantity item on the After Start checklist, the captain responded to the first officer’s prompt with an automatic response that the fuel was sufficient without looking at the fuel gauges. As a result, the aircraft departed Winnipeg with insufficient fuel on board to complete the planned flight.

During the flight, the crew did not include the fuel gauges in their periodic cockpit scans nor did they confirm their progressive fuel calculations against the fuel gauges. As a result, their attention was not drawn to the low-fuel state at a point that would have allowed for a safe landing.

When the left fuel pressure warning light illuminated and the flight crew realized they had insufficient fuel, they became startled. After declaring a fuel emergency with air traffic control, and initiating an emergency descent, the left engine lost power due to fuel exhaustion. Still feeling the effect of the startle response, the captain quickly became task saturated, which led to an uncoordinated response by the flight crew, delaying the turn towards Gillam and extending the approach. The right engine lost power due to fuel exhaustion when the aircraft was one nautical mile from runway 23. From that position, a successful forced landing on the intended runway was no longer possible.

More information: TSB Report.

Maintenance omission resulted in forced landing of a DHC-8 with a partially extended nose landing gear

RR Trent engine fan blade failure on A330-300 leads to enhanced inspection processes

A fan blade failure in an Airbus A330’s Rolls-Royce Trent 700 engine due to a fatigue crack has led to enhanced inspection processes and technical solutions that reduce the likelihood of future similar occurrences, a new ATSB investigation report details.

In June 2017, an AirAsia X Airbus A330-300 sustained an engine failure while operating a scheduled passenger flight from Perth to Kuala Lumpur. About one hour into the flight, during a step change in altitude, the flight crew heard a metallic bang, significant vibrations could be felt through the airframe, and an ‘ENG 1 STALL’ warning was triggered. The flight crew executed the relevant engine malfunction procedure and commenced a single-engine return to Perth. While the airframe vibrations continued during the return to Perth, the aircraft landed there without further incident.

On the ground an inspection found about three quarters of one fan blade was missing from the failed left engine.
Subsequent detailed structural analysis determined that the failure of the fan blade was due to a fatigue crack which had initiated from within the blade’s internal structure where an internal reinforcing membrane joins to the blade’s convex skin panel. Detailed structural analysis determined that the failure of the fan blade was due to a fatigue crack.

The report notes the blade manufacturing process produced a variation in the internal membrane-to-panel acute corner geometry that, in combination with the inherent high level of blade panel stress, could lead to increased localised stresses in those corner areas and the initiation and propagation of fatigue cracking.
The investigation also determined that the scheduled inspections recommended by Rolls-Royce to detect cracking in Trent 700 fan blades were insufficient to detect early onset fatigue cracks in the membrane to panel bond before those cracks could progress to failure.

Rolls-Royce have taken a number of proactive safety actions to mitigate future blade failures. These include reviewing the design and manufacturing of the Trent 700 fan blade and releasing service bulletins covering engine inspections (one of which was supported by a European Aviation Safety Agency (EASA) issued Airworthiness Directive).
The engine manufacturer also introduced new a control system modification, designed to shut the engine down quickly when fan blade failure event occurs to reduce damage to the fan shaft.

During the complex manufacturing process of Trent 700 fan blades, a latent issue developed that was not realised for a number of years, the investigation notes. This demonstrates the importance for manufacturers of critical components, and regulators monitoring the manufacturers, to have systems in place to quickly identify core issues and put in place measures to mitigate risk.

Iran details factors involved in the shootdown of Ukraine International Airlines flight PS752

Report: Boeing 787-9 cleared to wrong de-icing stand at Oslo Airport knocked over light pole

Maintenance and aircraft design factors in Air Astana ERJ-190 loss of control accident, Portugal

Report: Windshear on short final led to Airbus A321 tail strike accident at Charlotte-Douglas Airport