An accident involving a Cessna 208B Grand Caravan in Guadeloupe led the French accident investigating agency to recommend EASA to extend the obligation to carry a flight data recorder on board any aircraft in commercial air transport.

On September 5, 2010, the Cessna 208B suffered a failure of one or more blades of the turbine compressor when over sea, some eleven minutes after takeoff. Engine power was lost and the pilot shut down the engine and feathered the prop. The pilot attempted to return to the airport of Pointe-à-Pitre, Guadeloupe and tried to restart the engine. The engine could not be restarted and the pilot decided to carry out a  forced landing in a sugar cane field. The airplane sustained substantial damage but the pilot and six passengers were not injured.

The BEA investigators concluded that the accident resulted from a creep rupture of one or more blades of the turbine compressor leading to failure of the engine in flight. The causes of creep could not be determined. It could have resulted from operating the engine over the temperature-threshold or non-detection during maintenance.

The presence of a flight data recorder would have provided information on the parameters of the engine during the accident flight and previous flights.

More information:

• ASN Accident Description
• BEA report (in French)

Filed under: Investigation Reports, Safety Recommendations by admin
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File photo of Challenger 300 OH-FLM (photo: Eric Bannwarth / AviaScribe CC-by-nc-sa)

An inexperienced pilot caused an in-flight upset of a corporate jet when he overcontrolled the pitch immediately after the autopilot was disengaged, according to an investigation by the Finnish Safety Investigation Authority.

On 23 December 2010 a Bombardier BD–100–1A10 Challenger 300 business jet, registration OH-FLM, departed Moscow, Russia for St. Petersburg. The flight was a familiarisation flight for the co-pilot, who acted as Pilot Flying. There were three passengers and three crewmembers of the on board.

During the initial climb when the Engine Indication and Crew Alerting System (EICAS) annunciated an Autopilot Stabilizer Trim Failure (AP STAB TRIM FAIL) warning. In accordance with the fault checklists the captain disengaged the autopilot. This resulted in a porpoising oscillation which was quickly brought back under control. As a result of the occurrence two passengers were injured and some of the cabin interior was damaged. The aircraft returned to Moscow’s Sheremetyevo Airport.

Whereas the aircraft’s checklists advise the pilots to firmly grip the control column prior to autopilot disengagement, they do not instruct the flight crew to consider adjusting the airspeed to correspond to the horizontal stabilizer angle. Neither did the checklists include any mention of turning on the Fasten Seat Belt sign.
The cause of the occurrence was the overcontrolling of the aircraft’s pitch attitude immediately after the autopilot was disengaged. Contributing factors included the pilots’ unfamiliarity with the characteristics and operating principle of the aircraft’s artificial pitch feel system as well as shortcomings in system training. Further shortcomings were also observed in the flight crew’s checks and in crew cooperation. High airspeed was yet another contributing factor to the considerable acceleration (g) forces experienced during the upset.

More information:

• Finnish SIA report

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Peak acceleration during landing was +2.32g (graphic: AAIU)

Excessive approach speed and inadequate control of aircraft pitch during a crosswind landing in very blustery conditions caused a hard landing of an ATR-72 passenger plane at Shannon, Ireland, according to an AAIU investigation.

On July 17, 2011, an Aer Arann ATR-72 aircraft carried out a round trip from Shannon (SNN), Ireland to Manchester Airport (MAN), U.K. on behalf of Aer Lingus Regional. On the return leg, the crew commenced an approach in strong and gusty crosswind conditions. Following a turbulent approach difficulty was experienced in landing the aircraft, which contacted the runway in a nose-down attitude and bounced.
A go-around was performed and the aircraft was vectored for a second approach. During this second approach landing turbulence was again experienced. Following bounces the aircraft pitched nose down and contacted the runway heavily in a nose down attitude. The nose gear collapsed and the aircraft nose descended onto the runway. The aircraft sustained damage with directional control being lost. The aircraft came to rest at the junction of the runway and a taxiway.

The Irish Air Accident Investigation Unit (AAIU) concluded that confusing wording in the FCOM led the crew to compute an excessive wind factor in the determination of their approach speed. The inexperienced pilot-in-command, with 212 flying hours as captain on ATR-72 aircraft, used an incorrect power handling technique while landing. It was also established that inadequate information was provided to the flight crew regarding crosswind landing techniques.

More information:

• ASN Accident Description
• AAIU report

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Boeing 737-800 PK-LKS during the evacuation process (photo: NTSC)

The Indonesian National Transportation Safety Committee (NTSC), published a preliminary report of their investigation into the cause of the accident involving a Lion Air Boeing 737-800 near Bali, Indonesia.

On April 13, 2013 Lion Air Flight JT-904 crashed into the sea just 300 meters short of the runway threshold while on final approach to the Denpasar-Ngurah Rai Bali International Airport, Indonesia. There were 101 passengers and seven crew members on board. All aboard survived.

The flight departed Bandung with the copilot as Pilot Flying. About 15:00 the flight was descending towards Bali and the crew received vectors for a VOR DME approach for runway 09. At 15:08, with the aircraft at approximately 1,600 ft AGL, the Tower controller saw the aircraft on finals and gave a landing clearance with additional information that the wind condition was 120° at 5 kts.

While descending through 900 feet the copilot stated that the runway was not in sight. At 15:09:33, after the EGPWS called out “Minimum” at an altitude of approximately 550 ft AGL, the pilot disengaged the autopilot and the auto throttle and continued the descent. Twenty seconds later, at 150 ft AGL the captain took over control. The copilot handed the control to the captain and stated that he could not see the runway.

At 15:10:01, the EGPWS called out “Twenty”, and the captain commanded a go around. One second later the aircraft impacted the water.

As a result of the factual information and initial findings, the NTSC issued three immediate safety recommendations to Lion Air:

1. To emphasise to pilots the importance of complying with the descent minima of the published instrument approach procedure when the visual reference cannot be obtained at the minimum altitude.
2. To review the policy and procedures regarding the risk associated with changeover of control at critical altitudes or critical time.
3. To ensure the pilots are properly trained during the initial and recurrent training program with regard to changeover of control at critical altitudes and or critical time.

More information:

• ASN Accident Description
• Preliminary report (PDF)

Filed under: Investigation Reports, Safety Recommendations by admin
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30-second GPS data points were insufficient to determine the aircraft attitudes and movements leading up to the apparent loss of control, the pilot’s actions, and the functioning of the aircraft systems (source: TSB)

The Transportation Safety Board of Canada (TSB) is calling on Canada’s small aircraft operators to equip their fleets with lightweight recorders to monitor flight data, and is pressing Transport Canada to work with industry to make it happen. This TSB recommendation is part of an investigation report in which investigators could not conclusively determine why a de Havilland Canada DHC-3T Turbo Otter lost control and broke up in flight in the Yukon, Canada in March 2011.

The turbine-powered DHC-3 Otter, operated by Black Sheep Aviation and Cattle Co. Ltd, was flying from Mayo to the Rackla Airstrip in the Yukon, a 94-mile flight. Approximately 19 minutes after departure, the aircraft experienced a catastrophic in-flight breakup.  The aircraft broke up in flight and the pilot, who was the sole occupant died.

Investigators could not conclusively determine the cause of the break-up. While recorded flight data on larger transport aircraft has helped investigators determine the causes of accidents, smaller commercial aircraft usually don’t have recording devices.

In Canada, 91% of commercial aircraft accidents in the last 10 years involved these operators, and together, these accidents accounted for 93% of commercial aviation fatalities, TSB reported. Flight data monitoring could be an important tool to help smaller airlines to manage safety in their operations as well as help investigators in case of an accident.

More information:

• TSB press release

Filed under: Investigation Reports, Safety Recommendations by admin
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Surface movement radar picture showing illuminated stop bar and NEF025 (image: SAIF)

 The Finnish Safety Investigation Authority published their investigation report on a serious  runway incursion incident that occurred at Helsinki-Vantaa Airport on December 29, 2011 blaming the crew’s misinterpretation of traffic information and inadequate CRM. 

A Saab 340 aircraft operated by RAF-AVIA Airlines, call sign NEF025, was preparing to take off for a cargo flight and entered the runway. Simultaneously, a Golden Air ATR-72 aircraft, call sign BLF218, which had already been cleared to land, was approaching the same runway. NEF025 had two crew members. BLF218 had 67 passengers and 4 aircrew members.

In accordance with the instructions of the air traffic controller, NEF025 was taxiing to the holding point for runway 22R. Since NEF025 had not contacted Aerodrome Control Tower West (TWR-W), responsible for traffic on runway 22R, the controller switched on the red stop bar so that NEF025 would not taxi onto the runway in front of the landing aircraft. Shortly afterwards NEF025 called TWR-W. At this time the controller informed NEF025 of the landing aircraft: “NEF025 one landing”. The pilot-in-command of NEF025 interpreted the traffic information to be a clearance  to taxi onto the runway. Although the co-pilot was unsure of the clearance, the pilots did not confirm this from the air traffic control. NEF025 continued to taxi onto the runway past the illuminated stop bar.

The ATR-72 was approaching runway 22R and received a landing clearance from the TWR controller. During the final stage of the approach the pilots of the ATR-72 noticed that the runway was occupied and aborted the approach. Simultaneously, the TWR controller also noticed that NEF025 had entered the runway and cleared BLF218 for a go-around.

The serious incident occurred because the flight crew of NEF025 misinterpreted the traffic information, crossed the illuminated stop bar and entered the active runway 22R without an air traffic control clearance. Inadequate multi-crew cooperation between the pilots of NEF025 was a contributing factor.

In the spring of 2012 the Latvian Civil Aviation Agency (LV CAA) organised two flight safety meetings with RAF-AVIA and audited the company’s operations. As a result of the meetings and the audit LV CAA issued several recommendations for the purpose of correcting the observed anomalies. RAF-AVIA agreed to the recommendations of LV CAA.

Safety Investigation Authority, Finland (SIAF) issued five safety recommendations: two of them were directed at the Latvian Civil Aviation Agency and three at Finavia Corporation. Finavia maintains Finland’s network of 25 airports and the air navigation system.

SIAF recommend that LV CAA ensure that the pilots of RAF-AVIA are familiar with the procedures related to stop bars. Furthermore, SIAF also recommended that LV CAA make certain that RAF-AVIA pilots possess sufficient multi-crew cooperation skills.

SIAF recommend that Finavia emphasise the importance of disciplined radiotelephony communications in air traffic control operations and that Finavia focus particular attention on correct read-backs. Secondly, SIAF recommended that Finavia make certain that air traffic controllers include the pertinent air traffic control clearance, as applicable, when they complement the standard radiotelephony phraseology with traffic information. SIAF also recommended that Finavia study the possibilities of introducing a runway incursion alerting system.

More information:

• SIAF Incident Investigation Report

Filed under: Investigation Reports, Safety Recommendations by admin
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File photo of an Airbus A340-600 (photo: Merlin_1)

The General Civil Aviation Authority of United Arab Emirates is investigating a serious incident involving unreliable airspeed indications on an Airbus A340 over the Indian Ocean in February 2013.

On 3 February 2013 an Airbus A340-600, registration A6-EHF, had departed from Abu Dhabi International Airport, UAE on a scheduled passenger service to Melbourne International Airport, Australia with a total of 295 persons onboard. The captain was the pilot flying and the first officer was the pilot monitoring.

While cruising at FL350, just leaving Colombo FIR and entering Melbourne FIR over the Indian Ocean, the aircraft encountered moderate to heavy turbulence and experienced significant airspeed oscillations on the captain’s and standby airspeed indicators. The autopilot, autothrust and flight directors were disconnected automatically. The aircraft’s flight control law changed from “Normal” to “Alternate” Law, which caused the loss of some of the flight mode and flight envelope protections. The change from Normal to Alternate Law occurred twice, thereafter the Alternate Law stayed until the end of the flight. Autothrust and flight directors were successfully re-engaged, however, both autopilots (autopilot 1 and 2) could not be re-engaged thus the aircraft was controlled manually until its landing. Associated with that, the aircraft experienced high N1 vibration on No. 2 engine.

The flight crew decided to divert to Singapore Changi International Airport since the aircraft had lost the capability to maintain Reduced Vertical Separation Minimum (RVSM). Before landing, the flight crew dumped fuel in order to land the aircraft below its maximum landing weight.
The landing was uneventful and none of persons onboard was injured.

More information:

• Preliminary investigation report

Filed under: Investigation Reports by admin
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The accident airplane, C-GATV, pictured here at Yellowknife Airport, NT (YZF) in 2008 (photo: © Stuart Jessup)

The Transportation Safety Board of Canada (TSB) concluded that marginal weather and the pilot’s cannabis use were factors in a fatal accident in Canada in October 2011.

The Cessna 208B Grand Caravan was operating under visual flight rules (VFR) as Air Tindi Flight 200 from Yellowknife Airport, NT (YZF) to Lutsel K’e Airport, NT (YSG), Canada. The flight departed during daylight hours with one pilot and three passengers aboard. When it did not arrive on time, a search was launched, and the aircraft was found 26 nautical miles west of Lutsel K’e on high terrain near the crest of Pehtei Peninsula. The pilot and one passenger were fatally injured, and the two other passengers were seriously injured. Although no emergency locator transmitter (ELT) signal had been received, it was found to be operational when the search team found the aircraft.

The TSB investigation revealed that the aircraft was flown at low altitude into an area of low forward visibility, which prevented the pilot from seeing and avoiding terrain. Weather during the accident flight was marginal for VFR flight, and the aircraft did not have a terrain awareness and warning system (TAWS) or terrain-warning features on its GPS. The pilot, aircraft and company were all qualified to operate under instrument flight rules (IFR). Flying under IFR would have provided a margin of safety given the weather conditions. It could not be determined why the pilot chose to fly under VFR.

Toxicology testing revealed that concentrations of cannabinoids found in the pilot’s bloodstream were sufficient to have impaired pilot performance and decision-making during the flight.

According to the TSB, Air Tindi has taken measures to improve safety, such as dispatching all scheduled flights under IFR; installing cockpit imaging and flight data monitoring devices in its Cessna 208B fleet; and introducing random drug and alcohol tests for employees in safety-sensitive positions.
The ELT manufacturer made changes to its ELT designs to improve signal detection, and it also revised the instructions on how to secure ELT installations properly in aircraft.
Transport Canada enacted regulations requiring TAWS to be installed in all turbine-powered aircraft with 6 or more passenger seats by July 2014.

More information:

• TSB Accident Report
• ASN Accident Description

Filed under: Investigation Reports by admin
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The accident airplane, C-GKBC, seen here on takeoff from Patriot Hills, Antarctica

The Transportation Safety Board of Canada (TSB) reported that a recent fatal accident involving a Canadian DHC-6 Twin Otter in Antarctica was a Controlled Flight Into Terrain (CFIT) accident.

The TSB says it will conduct a full and independent investigation into the fatal January 2013 crash of a de Havilland DHC-6 Twin Otter operated by Kenn Borek Air Ltd. in Antarctica. The crew of three lost their lives in the accident.

On 23 January 2013, the Twin Otter was on a repositioning flight from South Pole Station, Antarctica, to Terra Nova Bay, Antarctica. There had been no radio communication from the aircraft and the flight was considered overdue. An emergency locator transmitter signal was received and search and rescue (SAR) was initiated. Extreme weather conditions hampered the SAR operation, preventing access to the site for two days. Once on site, the SAR team reported the aircraft’s crew did not survive. Adverse weather conditions, the effects of high altitude, unstable snow conditions and the state of the aircraft prevented the recovery of their bodies.

The TSB is conducting this investigation because the crew was Canadian, the aircraft was registered and manufactured in Canada, and there may be significant safety findings. “Everything we know at this stage points to a controlled flight into terrain (CFIT) accident, which is an issue on the TSB’s Watchlist,” said Mark Clitsome, Director of Air Investigations.

The TSB has examined the aircraft’s cockpit voice recorder (CVR). However, it did not record the accident flight. Investigators will continue to gather and analyze information to determine the causes and contributing factors of the accident.

The investigation is ongoing.

More information:

• ASN Accident Description
• TSB Press release

Filed under: Investigation Reports by admin
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No.4 engine cowlings of Boeing 707 ST-AKW (photo: GCAA)

A stall situtation during an emergency return to the airport after separation of the no.4 engine cowlings was concluded to have caused a fatal accident involving a Boeing 707 cargo plane , according to the UAE General Civil Aviation Authority (GCAA). It was also concluded that there was poor safety oversight within the airline as well as by the Sudanese CAA.

On October 21, 2009 a Boeing 707 cargo plane, owned by Azza Transport of Sudan, was destroyed when it crashed in a desert area immediately after takeoff from Sharjah Airport (SHJ), United Arab Emirates. All six on board were killed.

The airplane flew on behalf of Sudan Airways, carrying  air conditioning units, auto parts, computers and personal effects to Khartoum, Sudan. During initial climb, the core cowls of engine no. 4 separated and fell on the runway.

The aircraft continued in a shallow climb with level wings when the pilot informed the ATC that he lost engine no.4. He assumed this because the no. 4 Engine Pressure Ratio (EPR) manifold flex line had ruptured, leading to erroneous reading on the EPR indicator. The crew interpreted the EPR reading as a failure of the engine. Accordingly they declared engine loss and requested the tower to return to the airport.
The aircraft went into a right turn, banked and continuously rolled to the right at a high rate, sunk, and impacted the ground with an approximately 90° right wing down attitude.

The investigators concluded that the accident was caused by:
(a) the departure of the No. 4 engine core cowls;
(b) the consequent disconnection of No. 4 engine EPR Pt7 flex line;
(c) the probable inappropriate crew response to the perceived No. 4 engine power loss;
(d) the Aircraft entering into a stall after the published maximum bank angle was exceeded; and
(e) the Aircraft Loss of Control (“LOC”) that was not recoverable.

Contributing factors to the accident were:
(a) the Aircraft was not properly maintained in accordance with the Structure Repair Manual where the cowls had gone through multiple skin repairs that were not up to aviation standards;
(b) the Operator’s maintenance system failure to correctly address the issues relating to the No. 4 engine cowls failure to latch issues;
(c) the failure of the inspection and maintenance systems of the maintenance organization, which performed the last C-Check, to address, and appropriately report,
the damage of the No. 4 engine cowls latches prior to issuing a Certificate of Release to Service;
(d) the Operator’s failure to provide a reporting system by which line maintenance personnel report maintenance deficiencies and receive timely and appropriate guidance and correction actions;
(e) the Operator’s quality system failure to adequately inspect and then allow repairs that were of poor quality or were incorrectly performed to continue to remain on the Aircraft; and
(f) the SCAA safety oversight system deficiency to adequately identify the Operator’s chronic maintenance, operations and quality management deficiencies..

More information:

• ASN Accident description

Filed under: Investigation Reports by admin
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