If you wish to contribute or participate in the discussions about articles you are invited to join SKYbrary as a registered user

 Actions

T154, vicinity Smolensk Russian Federation, 2010

From SKYbrary Wiki

Summary
On 10 April 2010, a Polish Air Force Tupolev Tu-154M on a pre-arranged VIP flight into Smolensk Severny failed to adhere to landing minima during a non precision approach with thick fog reported and after ignoring a TAWS ‘PULL UP’ Warning in IMC continued descent off track and into the ground. All of the Contributory Factors to the pilot error cause found by the Investigation related to the operation of the aircraft in a range of respects including a failure by the crew to obtain adequate weather information for the intended destination prior to and during the flight.
Event Details
When April 2010
Actual or Potential
Event Type
Controlled Flight Into Terrain (CFIT), Fire Smoke and Fumes, Human Factors, Weather
Day/Night Day
Flight Conditions IMC
Flight Details
Aircraft TUPOLEV Tu-154
Operator Polish Air Force
Domicile Poland
Type of Flight Military/State
Origin Warsaw/Okęcie Frédéric Chopin Airport
Intended Destination Smolensk North Airport
Take off Commenced Yes
Flight Airborne Yes
Flight Completed No
Flight Phase Descent
ENR / APR
Location - Airport
Airport vicinity Smolensk North Airport
General
Tag(s) Flight Crew Training,
Approach not stabilised,
Non Precision Approach,
Inadequate Aircraft Operator Procedures,
Ineffective Regulatory Oversight
CFIT
Tag(s) Into terrain,
No Visual Reference,
Lateral Navigation Error,
Vertical navigation error,
IFR flight plan
FIRE
Tag(s) Post Crash Fire
HF
Tag(s) Distraction,
Inappropriate crew response - skills deficiency,
Inappropriate crew response (automatics),
Ineffective Monitoring,
Procedural non compliance,
Violation
WX
Tag(s) Fog
Safety Net Mitigations
Malfunction of Relevant Safety Net No
TAWS Available but ineffective
Outcome
Damage or injury Yes
Aircraft damage Hull loss
Fatalities Most or all occupants ()
Causal Factor Group(s)
Group(s) Aircraft Operation
Safety Recommendation(s)
Group(s) Aircraft Operation
Investigation Type
Type Independent

Description

On 10 April 2010, a Tupolev Tu-154M was being operated by the Polish Air Force Special Transport Regiment on a pre-arranged VIP fight for the Polish President and his entourage on a flight from Warsaw to Smolensk Severny, a Russian military aerodrome not normally available for use by international flights. During a ‘trial approach’ at destination by day in Instrument Meteorological Conditions (IMC) with thick fog reported at the aerodrome, the aircraft impacted ground obstacles and terrain below the level of the landing runway both some distance away from it and off the extended centreline. As a result of the impact and subsequent fire, the aircraft was destroyed and all occupants were killed.

Investigation

The Official Investigation into the Accident was carried out by the Technical Commission of the Interstate Aviation Committee (CIS) (IAC) (the ‘MAK’), which is the designated civil air accident investigation agency for the Russian Federation as State of Occurrence. The Investigation was carried out in accordance with the provision of ICAO Annex 13, with participation by accredited representatives and their advisers.

The Cockpit Voice Recorder (CVR) and Quick Access Recorder (QAR) were recovered and successfully replayed; the Flight Data Recorder (FDR) was badly damaged and of little use, but the QAR provided an identical record. The solid state memory from the GPWS/TAWS equipment fitted was also recovered.

In the final moments of the flight, at a position 1100 metres from the runway and 35 metres to the left of the extended centreline, it was found that part of the left wing of the aircraft had been detached by impact with an 11 metre high birch tree on ground which was 26 metres below the level of the runway threshold. As a result of this, it was concluded that the aircraft had rolled inverted to impact.

It was established that the aircraft and ground navigation aids had been serviceable prior to the accident. It was also confirmed that normal ATC procedures had been followed and that the aircraft had been conducting a non precision radar-monitored approach procedure to Runway 26 based upon Locator Beacons (NDBs) co-located with the Middle and Outer Markers on the prescribed track to the runway. The State minima for this approach were a visibility of 1000 metres and a MDH of 100 metres and ATC had confirmed this MDH with the aircraft commander.

It was noted from the CVR record that senior members of the Presidential delegation had been present in the flight deck during the approach, including the Air Force Commander-in-Chief. It was also noted that the aircraft commander on the accident flight had been the co pilot on a Presidential flight two years earlier when the aircraft commander had declined, on flight safety grounds to land at an airport other than the one which had been flight planned. Overall, it was concluded, after examination of all available evidence, that the aircraft commander would have perceived considerable pressure to make a successful landing at Smolensk. It was also considered that, based on an analysis of psychological test data made available by the Polish Air Force, the aircraft commander had “a dominating (tendency to) conformity“ in his character traits which would have affected rational response to stressful situations such as that encountered.

It was found that the aircraft commander was the only one of the four flight crew who was a Russian speaker and it was observed that, although he could be presumed to have been acting as PF, he had also conducted all R/T communications with Smolensk ATC. It was concluded that all the crew were relatively inexperienced on the aircraft type in their designated roles, especially so in respect of approaches to minima in limiting visibility conditions and noted that none had received any of their aircraft type training in a full fight simulator. Many actions by all the crew members during the approach were found to be not in compliance with those prescribed in the Flight Crew Operation Manual (FCOM) and there was little evidence of effective Crew Resource Management.

It was noted that, although the approach had been flown with the AP (and autothrottle) engaged and the aircraft controlled by use of the basic pitch wheel and roll control switch, the FCOM does not prescribe the use of the autopilot for a non precision approach because of the difficulty of achieving a constant rate of descent unless a vertical speed (VS) mode is available and used. In fact, the procedure descent was commenced late and the VS was increased to approximately twice the normal rate in order to regain the required vertical profile. However, it was not reduced when the desired profile was intercepted and remained at the same high rate so that the aircraft began to descend below it.

The flight crew were aware before starting their approach that the weather was below minima due to thick fog having drifted into the area below a temperature inversion at 400-500 metres aal. ATC advice of a visibility of 400 metres and that ‘no conditions for landing’ existed was effectively confirmed by conversations in Polish between the accident aircraft crew and the crew of another Polish military aircraft, a Yak-40, which had preceded the Tu-154 to Smolensk. This crew advised that the weather had significantly deteriorated since their landing and initially estimated the same visibility as ATC had advised with a vertical visibility of 50 metres, subsequently downgrading their estimated visibility to 200 metres. It was concluded that the aircraft commander had been aware that a successful approach was unlikely and noted that he had briefed the crew to expect a go around from the 100 metres MDH in the absence of visual reference as well as describing his approach to ATC as a ‘trial approach’.

The Investigation noted that the destination airport was not available in the TAWS database. It was found that the TAWS Caution ‘TERRAIN AHEAD’ had been activated twice - at about 340 m1,115.486 ft
aal and then at about 180 m590.551 ft
aal and had been followed at 105 m344.488 ft
aal by the TAWS Warning ‘TERRAIN AHEAD PULL UP’. There had been no crew response to any of the TAWS activations, or to descent below the MDH at 100 metres aal or the automatic ‘decision height alert’ call at 60 metres aal. In addition, the navigator had been making radio altimeter-sourced height call outs every 10 metres until 20 metres agl. Once activated, the TAWS ‘PULL UP’ Warning sounded continuously for 12 seconds of continued descent until, with about 10 metres to go to impact, the QAR record showed that a sudden attempt to overpower the autopilot and pull up had been initiated. It was concluded that action had probably been the result of ground sighting - the low height being consistent with estimates of the prevailing vertical visibility by ground witnesses. It was estimated that a Tu-154 at the weight, configuration and energy state of the accident aircraft as it approached terrain would have lost 30 metres altitude during the transition to a go around. It was also calculated that the final visually - triggered attempt to climb was made using such an abrupt manoeuvre that if the aircraft had not hit a tree, it would have stalled 1.5 - 2 seconds later due to the extreme angle of attack.

Causes

The Investigation concluded that:

“The immediate cause of the accident was the failure of the crew to take a timely decision to proceed to an alternate airdrome although they were not once timely informed on the actual weather conditions at Smolensk “Severny” Airdrome that were significantly lower than the established airdrome minima; descent without visual contact with ground references to an altitude much lower than minimum descent altitude for go around (100m) in order to establish visual flight as well as no reaction to the numerous TAWS warnings which led to controlled flight into terrain, aircraft destruction and death of the crew and passengers.

According to the conclusion made by the pilot-experts and aviation psychologists, the presence of the Commander-in-Chief of the Polish Air Forces in the cockpit until the collision exposed psychological pressure on the PIC’s decision to continue descent in the conditions of unjustified risk with a dominating aim of landing at any means.”

It was also concluded that:

Contributing Factors to the accident were:

  • long discussion of the Tu-154 crew with the Protocol Director and crew of the Polish Yak-40 concerning the information on the actual weather that was lower than the established minima and impossibility (according to the Tu-154M crew opinion) to land at the destination airdrome which increased the psychological stress of the crew and made the PIC experience psychological clash of motives: on the one hand he realized that landing in such conditions was unsafe, on the other hand he faced strong motivation to land exactly at the destination airdrome. In case of proceeding to an alternate airdrome, the PIC expected negative reaction from the Main Passenger;
  • lack of compliance to the SOPs and lack of CRM in the crew;
  • a significant break in flights in complicated weather conditions (corresponding to his weather minima 60 x 800) that the PIC had had as well as his low experience in conducting non-precision approach;
  • early transition by the navigator to the altitude callouts on the basis of the radio altimeter indications without considering the uneven terrain;
  • conducting flight with engaged autopilot and autothrottle down to altitudes much lower than the minimum descent altitude which does not comply with the FCOM provisions;
  • late start of final descent which resulted in increased vertical speed of descent the crew had to maintain.”

And that “the systemic causes of the accident involving the Tu-154M tail number 101 aircraft of the Republic of Poland were significant shortcomings in the organization of flight operations, flight crew preparation and arrangement of the VIP flight in the special air regiment.”

Safety Recommendations

Safety Recommendations were made during and at the conclusion of the investigation as follows:

  1. To the Commander of the Special Air Regiment of the Polish Air Forces:
    • Develop and implement the procedure of recurrent simulator training for the crews of the Tu-154M aircraft including checkrides to confirm the weather minima, training for various types of approaches as well as emergency situations training with an emphasis on the crew actions in case of TAWS warnings;
    • Develop and implement SOP guidelines for Tu-154M crews emphasizing the crew interactions:
      • during a non-precision approach with regard to monitoring the height by the flight instruments and distance from the runway;
      • using autoflight modes;
      • setting the decision height bug on the radio altimeter depending on the type of approach;
    • When dispatching flights consider the necessity of collecting all weather, navigation and other kinds of information for the intended flight route as well as the destination and alternate aerodromes especially when flying to aerodromes not listed in the AIP of the State of intended landing.
  2. To States: Consider the practicability of amending the national regulations to prohibit the presence of persons not included in the flight task in the cockpit as well as to determine liability for violating this provision.
  3. To States: Consider the practicability of amending the national regulations providing that any passenger flight regardless of the type of aviation shall be only conducted in compliance with the rules stipulated by the ICAO Convention, its Annexes and other pertinent documents including the rules of crew training, aircraft preparation as well as passenger and crew insurance aspects and carrier liability.
  4. To States: Consider the practicability of amending the national regulations providing all the necessary conditions including technical (check) flights to provide safety of international flights on airways and to airdromes not open for international air navigation.
  5. To Ministry of Defense of the Republic of Poland and Ministry of Defense of the Russian Federation: Take measures to enhance the role and efficiency of state control over flight safety in state aviation and eliminate the shortcomings mentioned in the Report.

The Investigation was concluded on 10 January 2011 and the Final Report was published by the MAK on 14 January 2011:

Separate Polish Investigation into the Accident

In late July 2011, a body called the "Polish Committee for Investigation of National Aviation Accidents" published an English language version of their own Final Report into the accident. It should be noted that this body is entirely separate from the Państwowa Komisja Badania Wypadków Lotniczych (PKBWL) which is the designated civil air accident investigation agency for Poland and is constituted as a division of the Ministry of Infrastructure.

Further Reading