Friday, May 21, 2010

Polish Air Force Tu- 154M crash in Russia latest information!

I discovered the following article by By Simon Hradecky, created Wednesday, May 19th 2010. The article appears to have the most factual information of any I have read so far. 

The Russian Interstate Aviation Committee (MAK) in cooperation with the Polish Accident Investigators published first preliminary results of their investigation stating, that there is no evidence in support of any inflight breakup, inflight fire or any mechanical malfunction prior to first impact with an obstacle 1100 meters before the runway threshold (see the sketch of the impact marks). 

The engines were working until final impact. The Terrain Awareness Warning System (TAWS), the Global Navigation Satellite System (GNSS) and the Flight Management System (FMS, UNS-1D) were working until final impact.

Airfield and navigation facilities were found suitable to receive the aircraft as well as the Polish Yak-40 that arrived 90 minutes prior to the Tupolev.

The cockpit voice recorder revealed, that persons not belonging to the flight crew were on the flight deck about 20 minutes prior to impact. Polish Authorities are working to identify the voices.

The captain of the flight had a total flying experience of 3480 hours, thereof 530 hours on the Tupolev TU-154. The first officer had 1900 hours of flying experience with 160 hours on the Tupolev, the navigator 1070 hours total with 30 on the Tupolev and the flight engineer had 290 hours total flying experience with 235 hours on the Tupolev.

The crew did receive weather forecasts for Smolensk North during the preflight briefing, but did not have the actual weather information. The crew did not have current aeronautical data for the airport nor did they have the current NOTAMs.

The crew interaction was unusual due to the introduction of the navigator. No procedures were available for that type of crew combination and interaction, as the airplane is usually flown with a 3-man cockpit (captain, first officer, engineer) and all training, documentation and manuals were set up only for a crew of three.

The flight departed Warsaw with a delay of one hour (actual departure at 07:27L CET [06:27Z] while departure was planned for 06:30L [05:30Z] and arrival for 09:45L Moscow time [06:45Z]). The crew interacted with air traffic control in Minsk and Moscow in English and communicated with the controller at Smolensk North Airport in Russian.

Minsk Control told the crew during the descent, when the airplane was at about 7500 meters (FL250), that Smolensk reported a visibility of 400 meters due to fog. The crew of the Polish Yak-40, which carried journalists and had already landed at Smolensk Airport 90 minutes prior to the accident, told the crew of the Tupolev 16 minutes prior to the crash, that a Russian Ilyushin 76 had gone around due to a ceiling of 50 meters and visibility of 400 meters. 

11 minutes prior to impact the Yak-40 crew radioed the Tupolev reporting the Russian Ilyushin had gone around a second time and diverted. 4 minutes prior to impact the Yak-40 crew radioed the Tupolev crew again reporting they estimated the visibility to 200 meters only. Smolensk Tower told the Tupolev crew, that visibility was 400 meters due to fog. The crew decided to carry out a "trial" approach to Minimum Descent Altitude (MDA) and then to decide whether to conduct a second approach. The final approach was flown on autopilot and autothrust. 

18 seconds prior to impact with the first obstacle the TAWS alerted "PULL UP! PULL UP!" after it had already warned "Terrain ahead!" prior to this. 5 seconds prior to impact with first obstacles the decision was made to go around and the autopilot was disconnected. 

The airplane first impacted a barrier 40 meters left of the extended centerline of the runway and 1100 meters before the threshold of the runway at an altitude, that was 15 meters BELOW the runway elevation. The third impact with an obstacle, a birch tree of 30-40cm trunk diameter contacted by the left hand wing, 840 meters before the runway threshold and about 80 meters left of the extended runway centerline, led to the first break up of the aircraft in flight, the aircraft rolled inverted and impacted ground 5 seconds later, that final impact occured at 10:41:06L (07:41:06Z). 

Impact forces were estimated in excess of 100G and were not surviveable.

Emergency services arrived at the crash site 13 minutes after the impact and cordoned the area off in a distance of 500 meters around the crash site, 180 personnel and 16 vehicles were on scene. Small fires at the crash site were extinguished 18 minutes after impact.

The airport of Smolensk North had been inspected on March 16th by Russian Experts to determine whether the airport was suitable for receiving Tupolev 134s and Tupolev 154s. The experts found runway 259, lighting, navaids and procedures suitable.

On March 25th test flights were performed which confirmed the suitability of the aerodrome.
On April 5th the aerodrome was again inspected in preparation for the special flights, the MDA was set to the 100 meters AGL (328 feet) with a visibility requirement of 1000 meters.

Specialists were on duty at the airport of Smolenks on April 10th starting at 07:00L to assist the incoming special flights. Those specialists inspected the runway lighting at 08:00L and found it operational with no defects. The lighting was subsequently operated at high intensity, specialists therefore were not able to inspect the lights immediately following the accident, but conducted the examination on April 11th. 

Pilot reports of other aircraft arriving on April 10th and 11th were acquired by the accident commission.
The investigation continues.