Introduction
On 5 May 2019, Aeroflot flight SU1492, operated by a Sukhoi Superjet 100-95B aircraft registered RA-89098, was conducting a scheduled domestic passenger service from Moscow Sheremetyevo (UUEE) to Murmansk (ULMM), Russia. Shortly after take-off, the aircraft was struck by lightning, which caused the flight control system to revert to Direct Mode. Following a return to Sheremetyevo, the aircraft made a hard landing, bounced multiple times, and suffered catastrophic structural failure on the third impact. A post-impact fire erupted, leading to the deaths of 41 of the 78 occupants.
The Interstate Aviation Committee (MAK) led the investigation, assisted by the Russian Ministry of Transport, the US NTSB, the French BEA, and aircraft and component manufacturers including Sukhoi Civil Aircraft and Curtiss-Wright.
This report presents the official findings, based on flight data and cockpit voice recorders, simulations, metallurgical analysis, structural examination, crew interviews, and ATC data.
Aircraft and Flight Information
• Aircraft Type: Sukhoi Superjet 100-95B
• Registration: RA-89098
• Serial Number: 95135
• Engines: 2 × PowerJet SaM146
• Operator: Aeroflot Russian Airlines
• First Flight: June 2017
• Total Time Since New: Approximately 2,710 hours
• Total Cycles: 1,660
• Flight Crew:
• Captain: 42 years old, ATPL, 6,800 hours total, 1,570 on type
• First Officer: 36 years old, CPL, 765 hours total, 615 on type
• Flight Route: Moscow Sheremetyevo (UUEE) to Murmansk (ULMM)
• Planned Flight Level: FL310
• Weather: Overcast, moderate wind, thunderstorm activity in the departure sector
• Runway: 24L
• Elevation: 622 ft AMSL
Sequence of Events
• 15:03 UTC: Aircraft took off from Runway 24C at Sheremetyevo Airport.
• 15:08: Aircraft was climbing through FL89 when it was struck by lightning. Both Electronic Interface Units (EIUs) rebooted, resulting in a loss of autopilot, flight director, and auto-throttle functions. The flight control system reverted from NORMAL MODE to DIRECT MODE, where control inputs have no flight envelope protections.
• 15:09: The crew reported the emergency via transponder code 7600 (radio failure), before establishing communication on 121.5 MHz. A return to Sheremetyevo was requested.
• 15:21: The crew initiated descent and began configuring for landing with flap setting 3, as prescribed in the QRH for operations in DIRECT MODE.
• 15:29: The aircraft intercepted the ILS for runway 24L. Despite a predictive windshear warning, the approach continued.
• 15:30:00 UTC: The aircraft made its first hard touchdown at 158 knots. The aircraft bounced.
• Second touchdown: Occurred 2 seconds later, at high descent rate, nose wheel touched down first. A second bounce followed.
• Third touchdown: Occurred at approximately 140 knots with vertical acceleration exceeding 5g. The main landing gear collapsed. Fuel tanks ruptured, causing a significant fire.
• 15:30:30: Aircraft came to rest. Fire rapidly consumed the rear fuselage.
• Evacuation: Initiated through forward doors. Rear exits were blocked by fire. Many passengers delayed evacuation by retrieving hand luggage. 41 occupants perished, 37 survived.
Wreckage and Impact Information
• Aircraft impacted the runway in a porpoising motion.
• The left and right main landing gears collapsed after structural overload.
• The right wing ruptured near the trailing edge and the wing root due to overload and fire.
• Fire damage was concentrated in the aft fuselage.
• No external impact or obstruction occurred before or during touchdown.
• No flight control or engine components were recovered with pre-impact failure evidence.
Flight Crew Information
Captain
• Age: 42
• Licence: ATPL (Airline Transport Pilot Licence)
• Total Flight Hours: 6,800
• Time on Type: 1,570 hours (1,428 hours in command)
• Last Line Check: April 2019
• Medical Certificate: Valid
First Officer
• Age: 36
• Licence: CPL (Commercial Pilot Licence)
• Total Flight Hours: 765
• Time on Type: 615 hours
• Medical Certificate: Valid
The captain had adequate experience and recent training on the aircraft, though gaps in his ability to fly in DIRECT MODE were later noted. The first officer was less experienced overall and had limited exposure to manual flight in degraded modes.
Lightning Strike and System Reversion
The aircraft was struck by lightning during climb. This event triggered a reversion of the Fly-by-Wire Control System (FBWCS) into DIRECT MODE due to a reboot of both Electronic Interface Units. This is a certified response under EASA/MAK certification standards and is classified as a major failure condition.
While this reversion itself did not endanger flight safety directly, it removed flight envelope protections, stall warnings, and autopilot functions, significantly increasing crew workload.
Crew Response and Stress Factors
Upon reversion to DIRECT MODE, the flight crew did not consult the QRH in full, and the captain made an immediate decision to return rather than assess flight characteristics. Audio analysis revealed high levels of emotional stress and communication breakdown between crew members. The captain took full control without formally delegating tasks or using standard crew resource management (CRM) protocols.
There was no stabilisation of pitch trim before descent and multiple errors were made in thrust handling and vertical control.
Approach and Landing Behaviour
Despite receiving a predictive windshear warning (GO AROUND WINDSHEAR AHEAD) and deviation below glideslope, the approach was continued. No go-around was attempted.
The approach was unstable:
• High indicated airspeed (170 knots vs 155 knot target)
• Deviations below glideslope ignored
• Manual pitch inputs were erratic
The first touchdown involved a hard landing (2.55g), followed by porpoising. The second bounce landed nose gear-first (5.85g), leading to excessive stress on landing gear. The third impact (5.0g) caused fuel tank rupture, wing spar failure, and immediate fuel-fed fire.
Evacuation and Fatalities
Evacuation was compromised due to:
• Rear exits inaccessible due to fire
• Panic and passenger behaviour, with some retrieving hand luggage
• Failure to shut down engines, worsening fire spread due to exhaust interaction with spilled fuel
• Flashover effect caused rapid spread of fire through cabin
41 people died, primarily from inhalation of hot gases and fire, not the initial impact. Autopsies confirmed smoke and thermal injury as cause of death for most victims.
Findings
1. The aircraft was struck by lightning during climb out.
2. The lightning strike caused system reversion to DIRECT MODE, a certified and expected behaviour.
3. The crew was inadequately trained for DIRECT MODE operations.
4. The flight crew failed to stabilise the approach or follow windshear escape procedures.
5. Multiple hard landings caused landing gear and wing spar structural failure.
6. Fuel leakage resulted in fire due to structural rupture.
7. The rear cabin was quickly engulfed by fire, and evacuation through the rear exits was impossible.
8. Crew did not shut down engines promptly.
9. Passengers delayed evacuation by retrieving baggage, further impeding escape.
10. Certification standards do not require survivability of cabin windows to external fire penetration.
11. Emergency evacuation could not be completed within 90 seconds due to fire spread and chaos.
Probable Cause
The accident was caused by uncoordinated and excessive control inputs by the captain during landing in DIRECT MODE, resulting in multiple hard touchdowns. The second and third landings caused structural failure of the landing gear and rupture of fuel tanks, which led to a fuel-fed fire.
Contributing Factors
• Insufficient flight crew training in handling DIRECT MODE emergencies
• Ineffective crew resource management under stress
• Failure to follow SOPs during approach and landing
• Inadequate response to windshear warnings
• Flight operation manual inconsistencies and vague guidance regarding DIRECT MODE handling
• Passenger behaviour during evacuation
• Structural vulnerabilities in gear/wings to repeated high-g landings
• Insufficient crew preparedness for high-stress decision-making
Safety Recommendations
1. Flight Crew Training: Operators of the SSJ100 must improve simulator-based training for degraded flight modes, especially DIRECT MODE.
2. CRM Enhancement: Airlines should strengthen CRM training for degraded system handling under stress, especially where standard protections are absent.
3. Procedural Clarity: Manufacturers must revise flight crew operating manuals to clarify windshear procedures and unstable approach criteria in degraded modes.
4. Evacuation Discipline: Reinforce cabin crew and passenger training on baggage abandonment during emergency evacuations.
5. Design Consideration: Regulators should reassess structural certification criteria for gear and wing integrity under repeated high-impact landings.
6. Fireproofing Improvements: Recommend evaluating fire barrier standards for cabin windows and rear fuselage.
7. Engine Shutdown SOPs: Emphasise immediate engine shutdown in post-impact fire scenarios where safe to do so.
Disclaimer
This report is based on official investigation materials, technical data, and flight recorder analysis available at the time of writing. It reflects the conclusions of the Interstate Aviation Committee (MAK) and restructured in accordance with CAA and FAA safety report formatting, written by a former engineer for educational and informational purposes only.
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