Tatarstan B735 crash during go-around at night. Learning from the recent past

On Nov 17th, 2013, a Tatarstan Airlines Boeing 737-500 flying from Moscow -Domodedovo to Kazan (Russia)  initiated a go-around while on short final to Kazan’s runway 29 but lost height, crashed onto or near runway 29 and burst into flames at 19:25L (15:25Z).  The aircraft came to rest off the runway. Organizational deficiencies, lack of adequate training, fatigue, and spatial disorientation were identified as contributing factors to the accident.

Kazan 735

Foto AFP: ALEXANDER KAMENSKY

A Tatarstan Airlines Boeing 737-500 on behalf of Ak Bars Aero, registration VQ-BBN performing flight U9-363/2B-363 from Moscow-Domodedovo to Kazan (Russia) with 44 passengers and 6 crew, initiated a go-around while on short final to Kazan’s runway 29 but lost height, crashed onto or near runway 29 and burst into flames at 19:25L (15:25Z). All occupants perished in the accident. The aircraft came to rest between the runway and main taxiway (former runway 11L/29R). The aircraft, tail number VQ-BBN, “fell onto the runway and burst into flames”.

tatarstan_b735_vq-bbn_kazan_131117_7

Photo: MAK-IAC

On Nov 19th, 2013 the MAK reported that first readouts of the flight data recorder revealed that the crew did not follow the standard approach profile, went around due to considering the approach as unstable (attitude not within stable approach parameters), the engine thrust levers were moved to TOGA and the autopilot disconnected, the aircraft was under manual control for the remainder of the flight.

The captain (47, ATPL, ILS Cat I, 2,784 hours total, 2509 hours on type) was pilot flying, the first officer (47, CPL, ILS Cat II, 2,093 hours total, 1,943 hours on type) was pilot monitoring.

While the engines accelerated to near takeoff thrust, the flaps were reduced from 30 to 15 degrees, the gear was retracted and the aircraft pitched up to about 25 degrees nose up, the indicated airspeed began to decay. Only after the airspeed had decreased from about 150 KIAS to 125 KIAS the crew began to issue control inputs to counter the nose up, the climb was stopped while the nose was lowered by control inputs. The aircraft reached a maximum height of 700 meters (2300 feet) and began to rapidly descend until the aircraft impacted ground at a nose down attitude of 75 degrees at a speed of 450 kmph (242 knots) about 20 seconds after reaching the maximum height of 700 meters. The engines were operating nominally until impact, the flight data recorders did not reveal any system malfunction, including no evidence of an elevator (editorial addition: or stabilizer) malfunction.

On Nov 28th, 2013 the MAK-IAC announced that the cockpit voice recorder has been successfully read out, the voices have been identified. There was no evidence of any person apart from Captain and First Officer on the flight deck.

Information released by Rosaviatsia, Russia’s Civil Aviation Authority, on Nov 28th 2013 based on preliminary investigation results by MAK-IAC states, that the captain of the flight (47, ATPL, 2736 hours total, 2509 hours on type, 528 hours in command) was rated for CAT I ILS approaches only, the first officer (47, no type of pilot rating provided, 2093 hours total, 1943 hours on type) was rated for CAT II ILS approaches.

According to preliminary information, the crew was significantly (4km) off the approach track prompting ATC to query the crew. Corrections were made, the aircraft remained significantly right of the extended runway centerline however until the crew selected heading 250 into autopilot (heading select mode) and the aircraft intercepted the localizer automatically about 2nm short of the runway threshold at about 1000 feet AGL, the glide slope did not capture due to height, however. After passing the missed approach point the crew discussed a go-around and communicated with dispatch, then disengaged both autopilots engaged in the automatic approach and continued manually on flight director. Engines accelerated to 83% N1 (near Go-Around Thrust) and continued at that speed until almost impact. The aircraft began to pitch up under the influence of engine acceleration and flaps retraction reaching 25 degrees nose up, the stabilizer trim system wound – most likely automatically – nose down commanding the aircraft into a dive.

In the meantime the crew retracted the gear, there had been no input on the yoke since deactivation of autopilot until that time and the airspeed had decayed from 150 to 125 KIAS. The crew now applied full forward pressure, the aircraft began to accelerate again after reaching a minimum speed of 117 KIAS at 700 meters/2300 feet above the runway, and began to rapidly descent, EGPWS alerts “SINK RATE” and “PULL UP” sounded, there was no reaction to the extreme nose down attitude however and the vertical acceleration became negative. The aircraft impacted the ground at 75 degrees nose down at about 450 kmph at coordinates N55.608818 E49.276852, the impact occurred 45 seconds after initiating the go-around and 20 seconds after reaching the maximum height.

Kazan accident

Image by Arz1969 – Own work, CC BY-SA 3.0 

Initial safety recommendations released were

  • to provide simulator training on balked landings that should be conducted in flight director mode with the special attention to scenarios, where the current minimum altitude is close to the target altitude during the missed approach procedure,
  • provide training on recognition of complex spatial disorientation and upset recovery,
  • provide training on operation and characteristics of aircraft systems especially autopilot and flight director during approach and missed approach,
  • study the features of the navigation system (FMS),
  • consider revision of air traffic control procedures to provide more assistance to crews with technical failures including providing vectors to guide the aircraft onto the runway and
  • conduct a conference to share technical flight experiences amongst operators.

On Sep 16th 2014 the MAK-IAC reported that the technical examination of the aircraft and aircraft systems has been completed with no technical fault having been identified. In particular, the hydraulic systems driving the elevator and horizontal stabilizers have been analyzed in laboratory analysis, which did not identify any anomaly. Mathematical modeling of failures of the actuators of elevators or horizontal stabilizers resulted in different flight trajectories than experienced in the accident flight. The technical commission, therefore, concluded that there was no evidence of any technical issue contributing to the accident sequence.

By MAK-IAC request, the French BEA performed a sensorial simulation with the aim to model how the crew could lose spatial orientation. The model suggested that after initiating the go-around the feel of the pitch angle of the crew and the actual pitch angle were in agreement until about +14 degrees when the nose rose further to 25 degrees the crew still felt the pitch increase to 17 degrees. Subsequently, when the actual pitch began to decrease the felt pitch continued to increase until reaching +25 degrees, in this phase first nose down inputs are recorded on the flight controls. The felt pitch and actual pitch subsequently completely separated, as the aircraft settled in the dive further increasing nose down inputs were recorded.

Likewise, the British AAIB performed simulations with the aim to determine whether somatogravic illusions were present. The AAIB concluded that in the absence of proper control of the instrument readings the crew could have perceived during the transition from climb to dive after the missed approach, that the aircraft was flying inverted.

In the meantime,  MAK-IAC analysed that the crew was using single autopilot Approach mode, which does not permit automatic go-around (unlike the dual autopilot approach mode) and would not perform automatic flare, touchdown and roll out. TOGA therefore automatically disconnected the autopilot and required the crew to continue manually on flight director.

A survey amongst Tatarstan pilots revealed, that in full flight simulator lessons they always used the dual autopilot when the approach mode was being used, which would result in an automatic go around on autopilot upon pressing the TOGA button. However, when in real flight and the crew did not intend to perform an automatic landing, they always used single pilot approach mode, which disallows an automatic go around.

During the probe process, MAK-IAC performed simulator tests with a number of pilots having them go through a scenario similar to the accident flight, in particular forcing a go around at intermediate height with the autopilot disconnecting at the initiation of the go-around by pressing the TOGA button. The MAK-IAC reported that the vast majority of crews coped well with the scenario but found it difficult to master reporting highly increased stress levels, especially when the pilot monitoring did not provide full assistance. A number of pilots, although the autopilot disconnecting aural and visual alerts are very distinct and have high attraction potential, did not catch the fact, that the autopilot had disconnected, several silencing the alerts by pressing the AP disconnect button, a number (about 42% of the pilots tested) not recognizing the alert at all and therefore responding with a substantial delay or not reacting at all. None of the pilots participating in the test was able to answer all questions to the procedures correctly, the MAK reported that 28% even believed the go around was automatic on autopilot despite the AP disconnect alert indicating the lack of knowledge and a substantial gap between theoretic knowledge and practical skills.

Of all pilots participating in the test, only one third mastered the go-around successfully. Only 28% attempted to achieve a suitable pitch angle after initiating the go-around aiming for +15 degrees of nose up, others began to react only between +20 and +37 degrees of nose up attitude and airspeeds as low as 90 KIAS with stick shaker activation. None of the pilots was able to level off at the assigned altitude.

In a second part of the experiment, a test pilot produced a pitch up upset similar to the accident flight and then let the participating pilot recover the aircraft. None of the pilots took the right decisions and none was able to recover the aircraft. The most common mistake was to believe, the control wheel would return to the neutral position on its own, this mistake, however, resulted in a substantial acceleration of the nose down movement resulting in rapid increase of the dive and vertical accelerations between +0.5G and -1.2G.

The common mistakes during the upset recovery noted by the MAK-IAC were the non-optimal application of flight controls especially if the aircraft is in a bank, no reselection of flaps in order to adjust to the current airspeed resulting in flap limit exceedance and loss of additional height, the non-use of speed brakes. The MAK-IAC reported, that after demonstration of the correct upset recovery technics almost all pilots were able to apply the technics and recover the aircraft, suggesting that the result of the experiment was mainly the result of lack of pilot training with respect to upset recovery.

The investigation could not identify, if, when and where the captain had undergone initial flight training. Of course, the captain had acquired certain piloting skills evidenced by passing the type rating upgrade course on a certified aviation training center and more than 2500 hours logged on the 737. At the same time, the captain showed serious lack of skills in emergency situations. The investigation established that Russia’s Civil Aviation Authority Northwest Regional Center issued the ATPL to the captain only 8 months after he allegedly acquired the license. The MAK stated that this was not a case of a forged pilot’s license, however, a case of lack of supervision and monitoring of pilot certificates by Rosaviatsia.

MAK-IAC analyzed further that the airline had all documents and possibilities at hand to identify that the ATPL had been granted to the captain unjustifiedly. For example, the MAK-IAC reasoned, the captain was conducting manufacturing flights to the airline when he, according to documents, was receiving training and passed examinations. Even a cursory check of the documents would have unveiled these discrepancies. The investigation authority analyzed that the Civil Aviation Authority of Tatarstan issued the ATPL formally, a reason for the (undue) issuance of the license was not provided.

On the other hand, was found that the first officer failed two exams for acquiring the theoretical commercial pilot’s license, on the third attempt he passed with 100% putting the result into serious doubt. The type rating took substantially more time (about 6 months) than normal, with a large pause between theoretical and simulator training. That simulator training was considered inadequate. For example, the MAK-IAC annotated the training was conducted by freelance instructors invited by the airline, there were two such instructors used on flight training devices and 5 on the full flight simulator.

Therefore, the investigation authority concludes that the pilot training, in general, was not carried out according to the principles set forth in FAR-23.

Additionally, the MAK-IAC analyzed that both pilots were suffering from the accumulation of fatigue. Although officially there had been sufficient rest time, evidence showed that there was a substantial revision of the work times leaving insufficient rest times to compensate for accumulated fatigue.

Regarding the ATC performance, it was analyzed that air traffic control observed the significant deviations from the approach procedure but did not offer assistance, i.e. vectors, to correct and compensate. The controller stated in post-accident interviews he had no idea he could have offered vectors. He believed, in contradiction to existing air traffic control regulations stating “the need for vectoring is determined by air traffic controller assessing the current air traffic situation. Vectors are offered to provide navigational assistance to flight crews.”, he needed an active request by the crew to provide vectors.

The MAK analysed that the priority in handling aircraft is “Aviate, Navigate, Communicate”. When the go-around was initiated priority was on “aviate”, however, at that time the first officer engaged in an ATC communication that lasted for 20 seconds and turned his attention away from monitoring flight instruments and the actions by the pilot flying. Therefore, he did not perform according to standard operating procedures, for example, missed to call out “positive rate of climb”, failed to point out the exceeding pitch angle, failed to point out speed deviations, … Only 20 seconds after the go-around was initiated the first officer “returned to the cockpit” and pointed out that the landing gear was still extended.

On Dec 23rd, 2015 the Commission of the Interstate Aviation Committee completed the investigation of the accident with Boeing 737-500 VQ-BBN aircraft operated by “Tatarstan “Airlines” JSC occurred in Kazan Airport on November 17, 2013.

“The fatal accident with Boeing 737-500 VQ-BBN aircraft was caused by system defects in the identification of hazard factors and risk level monitoring as well as non-operation of safety management system in the Airline and lack of monitoring on the crew members proficiency level from aviation authorities of all levels, which resulted in unprepared crew authorization for flights.

Performing go-around flight maneuver the crew didn’t identify the autopilot overriding and allowed the aircraft nose up upset. Lack of PIC’s skill of aircraft upset recovery resulted in significant deceleration, spatial disorientation and aircraft steep dive (pitch down angle up to 75°) down to ground impact.

Go-around flight maneuver was caused by the aircraft non-landing setting running out to the RWY that was caused by “Map shift” effect (aircraft position indication error by airborne systems) by the rate of 4 km, the crew disability to perform composite aircraft navigation and navigation with adequate accuracy as well as absence of ATM active assistance during long monitoring of significant deviations from the approach pattern.

The accident was caused by combination of the following factors [1]:

  1. lack of PIC’s initial flight training records;
  2. authorization for Boeing 737 conversion of the crew members not fully meeting the skill requirements for application for conversion including English language course;
  3. methodological imperfection of the conversion process, formal control over the conversion results and quality;
  4. low level of operation management in the airline that resulted in long-term non-elimination of identified deficiencies in working with navigation equipment, piloting technique and crew members interaction including during go-around flight maneuver;
  5. regular violation of the crew members work-rest regime and vacation liability that could result in chronic fatigue build and negatively affect the crew members performance;
  6. lack of go-around flight maneuver element from intermediate altitude with two operating engines in training programs;
  7. increased psycho-emotional tension of the crew members before go-around flight maneuver due to the long-term failure to identify the aircraft position with an accuracy to perform landing;
  8. violation of Aviate – Navigate – Communicate approach by the crew as well as by ATM service that resulted in non-adherence to standard operating procedures by the crew during go-around flight maneuver due to the long-term distraction of the first officer from performing their duties and flight data monitoring;
  9. not identification of the autopilot overriding by the crew and late interference with aircraft that resulted in aircraft nose up upset;
  10. imperfection of used training programs on the aircraft upset recovery and its quality evaluation criteria that resulted in the crew disability for the upset recovery;
  11. possible effect of somatic gravitational illusions
  12. non-adherence (by the Aviation authority) to the recommendations of the Investigation Commission of the accidents occurred before aimed at hazard factors elimination and risk level monitoring connected with:
  • lack of the appropriate monitoring system for pilots licensing, compliance of crew members training with specified requirements and rating assignment;
  • safety management system not operating in airlines, lack of methodological recommendations on their development and approval, formal approach to approval/coordination of safety management systems and crew training program on behalf of the authority;
  • imperfection of Aviation Training Center work and actual lack of monitoring over the conversion results;
  • lack of English language level requirements to the flight personnel for foreign type aircraft conversion and formal approach to English language level check;
  • lack of formal approach to the line and proficiency flight personnel check;
  • regular violation of work-rest regime;
  • insufficient training of flight personnel for go-around flight maneuver from intermediate altitude, aircraft manual operation mode and during it upset recovery;
  • “Map shift” effect at not equipped with GPS aircraft and insufficient crew members training for operation in such conditions;
  • necessity of active assistance to the crew from ATM service in case of detection of long-term deviation from specified procedures;

Appropriate recommendations for improving flight safety based on the investigation results are presented.

[1] In accordance with the ICAO’s Manual on Aircraft Accident and Incident Investigation (DOC 9756 AN/965) factors are presented in logical order without the priority evaluation.

Sources:

  1. Межгосударственный авиационный комитет- Interstate Aviation Committee (MAK-IAC) Final report
  2. The Aviation Herald
  3. Aviation Safety Network

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FURTHER READING

  1. The Head-Up Illusion: do you remember it?
  2. Armavia A320 crash during go-around at night in poor meteorological conditions
  3. Tatarstan B735 crash during go-around at night. Learning from the recent past
  4. Going around with all engines operating
  5. Speaking of going around
  6. Loss of flight crew airplane state awareness 

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minime2By Laura Victoria Duque Arrubla, a medical doctor with postgraduate studies in Aviation Medicine, Human Factors and Aviation Safety. In the aviation field since 1988, Human Factors instructor since 1994. Follow me on facebook Living Safely with Human Error and twitter@dralaurita. Human Factors information almost every day 

2 thoughts on “Tatarstan B735 crash during go-around at night. Learning from the recent past

    1. Indeed! It seems the information is not getting to the training departments soon enough! Maybe in the biggest airlines, the information is being studied, analyzed and used if it is needed, but in the regional, low-cost and small airlines maybe it is not. Thanks for your comment.

      Like

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