Preliminary Reference Information on Accident Investigation released April, 20th, 2016
Photo(C) Mike Kell
Межгосударственный авиационный комитет (МАК) – Interstate Aviation Committee Air Accident Investigation Commission (IAC)
Interim Report (Preliminary Reference Information) on Accident Investigation
Reporting organization: Interstate Aviation Committee
Type of occurrence: Accident
Aircraft: Airplane, Boeing 737-800
Owner: Celestial Aviation Trading 38 Limited, Shannon, County Clare, Ireland
Operator: Flydubai, United Arab Emirates
Place of occurrence Russia, Rostov Region, Rostov-on-Don Airport, coordinates: N 47º 15 ′ 54.7”; E 039 49 43.8″
Date and Time 19.03.2016 00:42 UTC, nighttime
On March 19, 2016, a Boeing 737-800 aircraft registered A6-FDN operated by Fly Dubai, while executing a recurrent approach at nighttime in IMC at Rostov-on-Don Airdrome with landing heading 218° the crew went around from the height of 220 m. From the height of about 1000 m the aircraft turned into descent and hit the runway about 120 m from the threshold.
The accident destroyed the aircraft and killed the crew and passengers.
The accident investigation is conducted by a team of investigators assigned by Order№ 9/765-Р of the Chairman of the Air Accident Investigation Commission, IAC of 19.03.2016.
Notifications of the accident were duly sent to the NTSB (USA), BEA (France), Air Accident Investigation Sector of GCAA (UAE) as well as States whose citizens had been killed in the accident.
Flight history and event description
On March 18, 2016, a Boeing B737-800 aircraft registered A6-FDN operated by Flydubai was conducting Flight FDB 981 en route Dubai – Rostov-on-Don. The crew consisted of a pilot in command and a first officer.
The cabin crew included 5 persons to serve the passengers in flight. The preflight briefing was conducted by the PIC on his own.
The weather forecast and actual weather along the flight route, at Rostov-on-Don airdrome and alternate airdromes of Krasnodar and Volgograd was not inhibitory for the flight and was consistent with the IFR conditions.
According to the data from the load sheet as well as the calculations done by the investigation team the aircraft takeoff weight on departure from Dubai was 68 tons with 17,3% center of gravity, which was within the AFM limitations (MTOW = 79 tons, CG range 10 – 31%).
The crew took a justified decision to depart.
At 18:37 the crew took off from Dubai Airport.
The cruise flight en route Dubai – Rostov-on-Don was at FL 360 as per flight plan.
Before starting descent the crew requested actual weather at Rostov-on-Don Airdrome and runway in use from the ATC.
At 22:42 as the crew of Flight FDB 981 was conducting the approach at Rostov-on-Don Airdrome with heading 218 magnetic, they informed the ATC officer of windshear on final (based on the on-board windshear warning) and went around climbing to FL 50 (1500 m), then climbing again to FL 80 (2450 m) to hold. While they were holding the crew reported moderate icing to the ATC and requested clearance to climb to FL 150 (4550 m).
The Radar and Approach ATC officers made numerous reports on the current actual weather to the crew of Flight FDB 981 as they were holding including the windshear data.
At 00:23 at 19.03.2016 the crew requested clearance to descend for another approach.
Both approaches (from the height of about 600 m) were performed with autopilot and autothrottle disengaged in flight director mode without significant heading or altitude deviations from the glideslope.
As the crew was proceeding with the approach (as per the FDR and CVR readout), the crew decided to go around again at a height of 220 meters (4,5 km before the runway) and initiated climb with vertical speed of up to 20 mps setting the engines to maximum takeoff/go-around thrust of 101 – 102% (N1).
One of the probable causes of the go-around decision could have been the 20-knot increase of indicated speed to as much as 176 knots within 3 seconds, which might have been an indication of a windshear.
In the course of the go-around, the crew set flaps to 15° and retracted the landing gear.
At the height of 1900 ft (approx. 600 m) after reaching the pitch angle of 18° the pilot flying pushed on the control column, which led to a decrease in vertical acceleration of up to 0.5, increase in forward speed and, consequentially, automatic retraction of flaps from 15° to 10° at a speed of over 200 knots.
The short-term decrease in engine thrust within 3 seconds resulted in decreasing speed and flaps extension to 15°, although the following crew inputs to regain maximum takeoff/go-around thrust led to speed increase and reiterated automatic flaps retraction to 10°. The flaps remained in the latter configuration until the impact.
The pilot flying, by pulling up the control column, continued climbing with a vertical speed of as much as 16 mps.
At a height of 900 m there was a simultaneous control column nose down input and stabilizer nose down deflection from -2,5 deg (6,5 units) to +2,5 deg (1,5 units) (the FDR recorded a nose down stabilizer input from the stabilizer trim switch of the control wheel lasting 12 seconds, while the CVR record contains a specific noise of rotation of the trim wheels located on both sides of the central pedestal), as a result, the aircraft, having climbed to about 1000 m, turned into descent with negative vertical acceleration of -1g.
The following crew recovery actions did not allow to avoid an impact with the ground.
At 00:41:49 the aircraft hit the runway about 120 m from the threshold with a speed of over 600 kmph and over 50 degrees nose down pitch.
The impact killed all persons on board and totally destroyed the aircraft.
Figure 1. Aircraft flight path.
Weather forecast for Rostov-on-Don Airdrome, valid at the time of the first go-around at 22:24 on 18.03.2016:
“… surface wind 250°, 7 mps, gust 13 mps, visibility 3000 m, light shower rain, mist, scattered clouds (3-4 oktas), cloudbase 300 m, broken (5-7 oktas) cumulonimbus, cloudbase 600 m, tempo from 18.03. 21:00 till 19.03. 06:00 surface wind 250°, 13 mps, gust 20 mps, visibility 1000 m, light shower rain, mist, clouds scattered (3-4 oktas), cloudbase 150, broken (5-7 oktas) cumulonimbus, cloudbase 600 m… “.
Actual weather at Rostov-on-Don Airdrome at the time of the first go-around as per ATIS information:
“… wind 230 degrees, 10 mps gust 17 mps, visibility 2900 m, light shower rain, clouds scattered at 480 meters, broken cumulonimbus at 990 m, temperature 6 degrees, dewpoint 3 degrees, QFE 742 mm/990 hPa, QNH 1000 hPa, moderate turbulence from surface to 1000 m; moderate icing in clouds at 900-1500 m, tempo wind 250 degrees 13 mps gust 18 mps, visibility 1000 m, shower rain, mist, clouds scattered cloudbase 90 m, broken cumulonimbus cludbase 600 m… “.
Weather forecast for Rostov-on-Don Airdrome, valid at the time of the accident on 19.03.2016:
“… surface wind 250°, 7 mps, gust 13 mps, visibility 3000 m, light shower rain, mist, scattered clouds (3-4 oktas), cloudbase 300 m, broken (5-7 oktas) cumulonimbus, cloudbase 600 m, tempo from 19.03. 00:00 till 19.03. 06:00 surface wind 250°, 13 mps, gust 20 mps, visibility 1000 m, light shower rain, mist, clouds scattered (3-4 oktas), cloudbase 150, broken (5-7 oktas) cumulonimbus, cloudbase 600 m…”
Actual weather at Rostov-on-Don Airdrome on 19.03.16 at 00:30 as per ATIS Information Echo:
“… surface wind 230 degrees, 12 mps gust 19 mps, visibility 3800 m, light shower rain, clouds scattered at 540 meters, broken cumulonimbus at 1080 m, moderate turbulence from surface to 1000 m; moderate icing in clouds at 900-1500 m, tempo wind 250 degrees 17 mps gust 25 mps, visibility 1000 m, shower rain, mist, clouds scattered cloudbase 90 m, broken cumulonimbus cludbase 600 m… “.
Actual weather at the time of the accident as per KRAMS-4 weather station data at 00:42:
“… surface wind magnetic 230 – 13 gust 18 mps, visibility 7000/7000/3700 m (heading in use/middle/back track), light shower rain, clouds scattered (4 oktas) cloudbase 420 m broken (5-7 oktas) cumulonimbus cloudbase 1080 m, overcast (8 oktas) cloudbase 3000 m, temperature +6,3С, dewpoint +3,6С, moisture content 84%, QNH 998,0 hPa, QFE 742 mm mercury/988 hPa, magnetic heading 218, RWY status R22/290046, moderate icing in clouds at 900-1500 m, moderate turbulence from surface to 1000 m; forecast for landing: tempo wind 250-17 gust 25 mps, visibility 1000 m, shower rain, mist, clouds scattered cloudbase 90 m, broken cumulonimbus cloudbase 600 m…”.
The aircraft was equipped with a Honeywell SSFDR P/N 980-4700-042, S/N 35907 and an L3 CVR FA2100 2100-1020-00.
The flight recorders were found at the accident site with substantial mechanical damage (Figures 3, 4). The flight recorders were delivered to IAC where they were examined and the status of memory modules was assessed including X-ray examinations.
As a result of the operations including recovery of memory unit information cables conducted in the laboratory of the IAC with participation of investigators from the UAE and France, the data from the FDR and CVR were successfully downloaded and read out.
At the time of the Report publication the investigators are completing the hearing out and transcript of all of the recorded CVR information that constitutes 2 hours of record.
Tests and Research
Units and components of the accident aircraft selected for tests and examinations were transported to the Interstate Aviation Committee. At the time of the Report publication the facilities and organizations to conduct the pertinent examinations are being discussed.
Currently, the investigation team has planned, among others, for the following activities:
- clarifying the content of the CVR transcript, translating it from English and Spanish and identifying the speakers at IAC laboratory facilities (with participation of investigators from the UAE, USA and Spain);
- mathematic simulation of the aircraft flight and assessment of the control system operability;
- examination of the psycho-emotional and physiological status of the crew taking into consideration the data about the crew work and rest time;
- expertise of the aircraft control system architecture and ergonomic in the longitudinal channel including the stabilizer trim control.
Prompt Safety Recommendations
For the purpose of preventive measures the investigation team recommends to:
- Inform the flight and maintenance personnel operating Boeing В737-800 airplanes on the accident.
- Have additional training on elements of go-arounds in various conditions, in manual control mode with two engines operative from various heights and with insignificant flight weights.
- To study the possibility of introduction into the FFS training program scenarios of go-arounds in various conditions, in manual control mode with two engines operative from various heights.
- Repeatedly study and analyze the implementation of safety recommendations issued by investigation teams of accidents involving the Boeing 737-500 aircraft registered VQ-BBN on 17.11.2013 at Kazan Airport (See: Tatarstan B735 crash during go-around at night. Learning from the recent past) and the A320 aircraft registered EK 32009 on 3.05.2006 near Sochi Airport (See: Armavia A320 crash during go-around at night in poor meteorological conditions).
- Repeatedly analyze the applicability of recommendations to prevent accidents and incidents during go-around, developed by the BEA based on the safety study related to Aeroplane state awareness during go-round (ASAGA). Depending on the results of the analysis, take applicable safety measures.(See: Going around with all engines operating)
Excerpted from Межгосударственный авиационный комитет (МАК) – Interstate Aviation Committee Air Accident Investigation Commission (IAC), Interim Report (Preliminary Reference Information) on Accident Investigation.
About the investigation of the accident with Boeing 737-800 A6-FDN aircraft, Межгосударственный авиационный комитет (МАК) – Interstate Aviation Committee Air Accident Investigation Commission (IAC)
- The Head-Up Illusion: do you remember it?
- Armavia A320 crash during go-around at night in poor meteorological conditions
- Tatarstan B735 crash during go-around at night. Learning from the recent past
- Going around with all engines operating
- Speaking of going around
- Loss of flight crew airplane state awareness
No wind shear or other meteorological issues that could induce the loss of control, no technical malfunction. It seems the Human Factors issues are going to be of high importance. The Human Factors, of which very little is spoken in the basic flight schools, airline ground schools, in the design of training programs and material, training of instructors, service time and rest schedules…
They have found some of the What and the How. The Whys are the most difficult part of the investigation and take much more time.
On March 20, 2017, MAK release an update statement: “In accordance with Standard 6.6 of Annex 13, “Accident and Incident Investigation” to the Convention on International Civil Aviation, the Chairman of the Commission for the Investigation of the Accident with the Boeing 737-800 A6-FDN Airplane a / to Flydubai, which took place on March 19, 2016 at the Rostov- On-Don, informs that the Commission carried out a set of works necessary to determine the causes, circumstances and factors of the accident and develop measures to prevent similar disasters in the future.
Operational recommendations for the prevention of accidents were given by the commission in the interim report (preliminary information) on the progress of the investigation on April 20, 2016.
In accordance with ICAO standards, the work of the commission is carried out in cooperation with the authorized representative of the National Transportation Safety Committee (NTSB) of the United States, as the State of the developer and manufacturer of the aircraft, as well as the accident investigation sector of the General Aviation Administration of the UAE, both the State of Registry and the Operator of the Aircraft .
The Commission of Inquiry received all the necessary amount of factual information and at the moment its detailed analysis is completed with the participation of experts from interested states to prepare the draft Final Report.” Boeing 737-800 А6-FDN 19.03.2016
By 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