ClosedMedium impactAI Generated

Singapore Airlines SQ321 Fatal Turbulence Incident Over Myanmar – Weather Radar Investigation

Occurred 21 May 2024·Detected 21 May 2026·
🇸🇬 Southwest Myanmar airspace, approximately FL370, en route London Heathrow to Singapore1 reportEnded 29 May 2026
AviationAviationCasualty & Liability

Singapore Airlines flight SQ321, a Boeing 777-300ER (9V-SWM), encountered severe clear-air turbulence over southwest Myanmar on 21 May 2024 while en route from London Heathrow to Singapore, resulting in one fatality and 56 serious injuries. Singapore's Transport Safety Investigation Bureau is investigating whether a weather radar 'underpainting' malfunction failed to display hazardous conditions to the crew. The aircraft diverted to Bangkok, and subsequent testing revealed possible intermittent radar underpainting. Investigators have recommended development of cockpit weather radar recording capability, which is currently absent on pre-2023 certified aircraft types.

AI-generated from linked source reports. See our correction policy.

Impact verdict

Medium impact. MEDIUM: High-row recalibration. The Singapore Airlines SQ321 turbulence event creates Aviation Liability, passenger injury, potential hull and regulatory exposure. Impact is not HIGH absent hull loss, fleet-wide grounding, product-liability finding, major claims estimate, or market-wide aviation pricing response.

View assessment methodology

How we grade what we know -- Known · Reported · Uncertain. Methodology →

Intelligence ledger

Each line expands in place to its underlying sourced claim.

Known10 lines

SQ321 (9V-SWM) suffered severe turbulence at 37,000ft over southwest Myanmar on 21 May 2024
structured lineknown
No separate sourced-claim record is available for this line yet.
One passenger was fatally injured; 56 other occupants were seriously injured
structured lineknown
No separate sourced-claim record is available for this line yet.
The aircraft was a Boeing 777-300ER operating London Heathrow to Singapore
structured lineknown
No separate sourced-claim record is available for this line yet.
The aircraft diverted to Bangkok following the incident
structured lineknown
No separate sourced-claim record is available for this line yet.
Both navigation displays were set to 320nm range at the time of the encounter
structured lineknown
No separate sourced-claim record is available for this line yet.
The turbulence encounter lasted approximately one minute, including 21 seconds of manual flight
structured lineknown
No separate sourced-claim record is available for this line yet.
12 reports of weather radar underpainting were found in fleet maintenance records from May 2023 to July 2025 across ~29,000 flights
structured lineknown
No separate sourced-claim record is available for this line yet.
Two prior underpainting reports related to the incident aircraft were filed on 29 April and 1 May 2024
structured lineknown
No separate sourced-claim record is available for this line yet.
ICAO requires crew-machine interface recording only on large aircraft certified after 1 January 2023
structured lineknown
No separate sourced-claim record is available for this line yet.
No weather radar image recording capability existed on this aircraft
structured lineknown
No separate sourced-claim record is available for this line yet.

Reported4 lines

The commander reported no clouds in the immediate flightpath and no weather returns on navigation displays prior to the event
structured linereported
No separate sourced-claim record is available for this line yet.
After the upset, weather returns were still absent above 31,000ft but appeared below that altitude
structured linereported
No separate sourced-claim record is available for this line yet.
During a ferry flight on 26 May 2024, crew observed possible radar underpainting and photographed the displays
structured linereported
No separate sourced-claim record is available for this line yet.
The investigation team opines the radar was painting weather returns intermittently during the occurrence flight
structured linereported
No separate sourced-claim record is available for this line yet.

Uncertain3 lines

Whether the weather radar was definitively underpainting conditions at the time of the turbulence encounter remains unconfirmed
structured lineuncertain
No separate sourced-claim record is available for this line yet.
The radar manufacturer disputes the validity of ferry-flight tests and claims no evidence of malfunction during the incident
structured lineuncertain
No separate sourced-claim record is available for this line yet.
Investigators noted 'some unusual behaviours' during extensive radar testing but no conclusive findings have been published
structured lineuncertain
No separate sourced-claim record is available for this line yet.

Geographic Zone Matches

2 active matches

  • EU Sanctions List
    Rule-basedConfidence 100%
  • High Piracy Risk - Strait of Malacca
    Rule-basedConfidence 100%

Geographic zone matches are RiskEvents spatial/analytical indicators, not coverage determinations or Lloyd's official classifications.

Affected countries

🇬🇧 United Kingdom🇲🇲 Myanmar🇸🇬 Singapore🇹🇭 Thailand

Timeline

Status Change2 Jun 2026, 13:05

Lifecycle changed

monitoring → closed

Closure2 Jun 2026, 13:05

Event Closed

auto_closed_monitoring_timeout

Status Change29 May 2026, 05:30

Status changed to monitoring

Auto-transitioned: no updates for 6 hours

active → monitoring

Status Change28 May 2026, 22:36

Status changed to active

remediation: existing authoritative signal

signal → active

De-escalation25 May 2026, 18:22

Impact changed

high → medium

Initial Detection21 May 2026, 16:34

Initial Detection

Singapore Airlines flight SQ321, a Boeing 777-300ER (9V-SWM), encountered severe clear-air turbulence over southwest Myanmar on 21 May 2024 while en route from London Heathrow to Singapore, resulting in one fatality and 56 serious injuries. Singapore's Transport Safety Investigation Bureau is investigating whether a weather radar 'underpainting' malfunction failed to display hazardous conditions to the crew. The aircraft diverted to Bangkok, and subsequent testing revealed possible intermittent radar underpainting. Investigators have recommended development of cockpit weather radar recording capability, which is currently absent on pre-2023 certified aircraft types.

The inquiry into the accident points out that there was no means of recording the weather radar images presented to the crew...the commander was 'surprised' as no clouds had been observed, nor had there been weather returns on the navigation display — even with the 'gain' knob set to maximum.

Source: FlightGlobal (Trade Media) · View source

Lloyd's classifications

Tracking this kind of risk? Get an email when Aviation events escalate.

Get alerts