FlySafe was not operational during this event. This analysis reconstructs publicly available signals — to demonstrate how predictive airspace intelligence could have provided advance warning.
China–Taiwan Joint Sword 2024A
May 2024 — 84 Flights Cancelled, 1-Day Notice
On May 23, 2024 — one day after President Lai Ching-te's inauguration — China's People's Liberation Army launched 'Joint Sword 2024A,' a military exercise that encircled Taiwan with naval and air assets. Live-fire zones were declared within the Taipei FIR (RCAA) with barely 24 hours' notice, violating ICAO's Annex 15 requirement of 7 days for hazardous activity notifications. Eighty-four flights were cancelled. China Airlines, EVA Air, Starlux, and international carriers rerouted around the exercise zones. The drills involved aircraft carriers, destroyers, fighter jets, and simulated cross-border aerial action. Taiwan's airspace sovereignty was directly challenged — not theoretically, but operationally.
What Happened
On May 23–24, 2024, the People's Liberation Army launched "Joint Sword 2024A" — a large-scale military encirclement exercise around Taiwan. Triggered directly by the inauguration of President Lai Ching-te on May 20, the drills deployed PLA Eastern Theater Command forces including the aircraft carrier Shandong, multiple destroyers, fighter jets, bombers, and maritime patrol aircraft. Live-fire zones were declared inside the Taipei Flight Information Region (RCAA) with approximately 24 hours of notice — against an ICAO Annex 15 standard that requires a minimum of 7 days for hazardous activity NOTAMs. The result: 84 flights cancelled, dozens more rerouted, and a full-day disruption to one of the busiest cross-strait and trans-Pacific aviation corridors in the world.
This was not an isolated incident. Joint Sword 2024A was the third major PLA encirclement drill since August 2022, when similar exercises followed US Speaker Nancy Pelosi's visit to Taipei. Each successive drill has come with shorter advance notice and expanded exercise footprints, creating a worsening pattern of NOTAM compliance that directly threatens the international aviation planning cycle.
- —Aircraft carrier Shandong (CV-17) battle group
- —Destroyers and frigates, Eastern Theater Command
- —J-11, J-15, J-16 fighter jets across median line
- —H-6K bombers, Y-8 maritime patrol aircraft
- —Simulated precision strike on key Taiwan targets
- —Exercise zones declared on all four sides: north, south, east, west
- —84 domestic and international flights cancelled
- —China Airlines, EVA Air, Starlux, Tigerair Taiwan rerouted
- —Singapore Airlines, Japan Airlines, Cathay Pacific diverted
- —~24h NOTAM notice vs. ICAO 7-day requirement
Warning Signs
The political trigger for Joint Sword 2024A was publicly known weeks in advance. Lai Ching-te's inauguration date of May 20, 2024 had been confirmed since his election victory on January 13, 2024. Beijing had labeled Lai a "dangerous separatist" and explicitly warned of consequences following his election. For risk-aware operators, the window between January and May presented a clear geopolitical loading condition — a known inauguration, a hostile response posture from Beijing, and a well-established precedent from the August 2022 Pelosi drills. Multiple signal categories elevated risk to actionable levels days before the NOTAMs were ever issued.
Lai Ching-te's inauguration date (May 20) was public since January 2024. Beijing's hostile posture toward Lai was explicitly stated by PLA spokespeople and Chinese state media throughout Q1 2024. The political trigger was not ambiguous — it was announced.
August 2022 (Pelosi visit): large-scale encirclement, ~48h notice. April 2023 (Tsai–McCarthy meeting): Follow-on "combat readiness patrols," shorter notice. May 2024 (Lai inauguration): ~24h notice. Each trigger event was preceded by explicit PLA statements. The pattern of shrinking notice windows was already analytically visible.
Chinese state media (Xinhua, Global Times) published explicit warnings in the days following Lai's election and again ahead of the May 20 inauguration. PLA Eastern Theater Command's social media accounts used language consistent with pre-exercise posturing seen in both 2022 and 2023 episodes.
The Taipei FIR handles significant trans-Pacific routing for carriers connecting Japan, South Korea, the Philippines, and Southeast Asia with North America and Europe. Disruption to RCAA carries immediate cascade effects across adjacent FIRs — FUKUOKA, MANILA, and HONG KONG — elevating systemic exposure beyond Taiwan-based airlines alone.
ICAO Annex 15 requires 7 days advance publication for NOTAMs relating to hazardous activities. The August 2022 drills gave approximately 48 hours. By May 2024 this had compressed to roughly 24 hours. This structural regression is analytically trackable across episodes and represents a systemic risk to the global aviation planning cycle, not a one-time anomaly.
Timeline
Lai Ching-te wins Taiwan presidential election with 40.1% of the vote. Beijing immediately condemns the result, with PLA Eastern Theater Command issuing a statement warning against "separatist collusion with external forces." Inauguration date of May 20, 2024 is publicly set — establishing a known geopolitical flash point approximately 18 weeks out.
Chinese state media escalates rhetoric ahead of inauguration week. Xinhua and Global Times publish editorials explicitly framing Lai's inauguration as a provocation. PLA spokespeople use language — "firm action," "legitimate and necessary" — consistent with pre-exercise signaling language used before August 2022 and April 2023 episodes. No NOTAMs issued. Airlines continue operating normal schedules.
Lai Ching-te is inaugurated as President of Taiwan. In his inauguration speech he reaffirms Taiwan's democratic identity and does not offer concessions toward Beijing. Within hours, PLA Eastern Theater Command publishes a statement announcing that military exercises "around Taiwan" are imminent, without specifying dates, zones, or flight level restrictions. Taiwan's Civil Aeronautics Administration (CAA) and Taipei ACC begin monitoring for formal NOTAMs.
PLA officially announces "Joint Sword 2024A" will commence the following morning, May 23. NOTAM alerts begin publishing through Taipei ACC for hazardous areas within the RCAA FIR. Effective notice window: approximately 12–18 hours depending on zone. ICAO Annex 15 standard requires 7 days (168 hours). Airlines scramble to assess impact and implement contingency routings. China Airlines, EVA Air, Starlux Airlines, and Tigerair Taiwan operations centers activate disruption protocols overnight.
Joint Sword 2024A commences. PLA forces establish exercise zones encircling Taiwan on all sides — north, south, east, and west. The aircraft carrier Shandong (CV-17) operates east of Taiwan. Destroyers and frigates take positions to the north and south. Fighter jets cross the Taiwan Strait median line in multiple sorties. Simulated precision strike operations are conducted against designated target sets. 84 flights are cancelled by morning. Dozens of scheduled departures and arrivals at Taoyuan (TPE), Songshan (TSA), Taichung (RMQ), and Kaohsiung (KHH) are affected.
International carriers operating long-haul routes through the Taipei FIR are diverted or rerouted. Singapore Airlines transpacific services adjust routing south of the exercise zones. Japan Airlines and Cathay Pacific Pacific-sector flights reroute via alternative waypoints north of Taiwan, adding significant track miles and fuel burn. FUKUOKA FIR and MANILA FIR experience increased traffic density as carriers shift routing away from RCAA. No mid-air incidents are reported, but the compression of traffic into adjacent corridors elevates controller workload.
Exercise activity continues into the second day. PLA Eastern Theater Command releases footage of missile launches and naval maneuvers surrounding Taiwan. Exercise zones remain active. Further cancellations and delays compound Day 1 disruptions, with passenger re-accommodation costs accumulating across affected carriers. Taiwan's CAA works with ICAO and adjacent ATC units to manage traffic flow.
PLA Eastern Theater Command announces the conclusion of Joint Sword 2024A. Exercise zones are cancelled. Taipei FIR returns to normal operations. Airlines begin restoring disrupted schedules. The episode is formally logged as the third major PLA encirclement exercise since August 2022, with the shortest advance notice of the three.
Aviation Impact
The operational impact of Joint Sword 2024A extended far beyond the 84 cancelled flights directly attributed to the exercise. The simultaneous encirclement of Taiwan on all four sides eliminated the standard contingency routing options that airlines typically rely on when partial airspace restrictions are imposed. With exercise zones declared to the north, south, east, and west of Taiwan within the RCAA, there was no safe alternative track within the Taipei FIR — a scenario without precedent in peacetime commercial aviation at this scale.
Direct cancellations across domestic and international operations at Taoyuan (TPE), Songshan (TSA), Taichung (RMQ), and Kaohsiung (KHH). China Airlines, EVA Air, Starlux Airlines, and Tigerair Taiwan bore the bulk of the operational burden, with international carriers including Singapore Airlines, Japan Airlines, and Cathay Pacific also affected.
The functional window between first NOTAM publication and exercise commencement was approximately 12–24 hours depending on the zone. ICAO Annex 15 mandates 7 days (168 hours) for hazardous activity NOTAMs. This represents a compliance shortfall of approximately 93%, the worst of any of the three PLA encirclement exercises since 2022.
Unlike partial-restriction scenarios where carriers can reroute around an affected sector, the simultaneous declaration of exercise zones on all sides of Taiwan eliminated all within-FIR contingency options. Traffic was forced entirely out of the Taipei FIR, creating significant compression in the FUKUOKA and MANILA FIRs and extended track miles for trans-Pacific operators.
Joint Sword 2024A was the third in a documented series of major PLA encirclement exercises: August 2022 (Pelosi visit, ~48h notice), April 2023 (Tsai–McCarthy meeting, reduced notice), May 2024 (Lai inauguration, ~24h notice). The trend line — both in frequency and notice compression — is analytically established and points to continued deterioration of ICAO compliance in this region.
Taiwan's two full-service flag carriers. Heavily exposed on cross-strait, northeast Asia, and transpacific routes. Both maintain operational bases at Taoyuan (TPE) and operate schedules that were directly disrupted by all-sides encirclement. Highest absolute cancellation exposure of the event.
Younger carriers with growing regional networks concentrated in the Taipei FIR. With less route redundancy than legacy carriers, both faced proportionally higher disruption relative to fleet size. Tigerair Taiwan's short-haul network was particularly impacted by the complete airspace closure.
International carriers with transpacific and intra-Asia routes transiting the Taipei FIR. Rerouting added significant track miles and fuel costs. Japan Airlines routes between Tokyo and Southeast Asia are particularly RCAA-dependent, as the standard routing passes through or adjacent to Taiwan airspace. Cathay Pacific's dense northeast Asia–Southeast Asia network was similarly affected.
Takeaway
Joint Sword 2024A is a textbook case of a predictable disruption that the industry treated as a surprise. Every component of this event — the political trigger, the geographic scope, the notice window — had structural precedent in publicly available data. The failure was not a lack of information. It was a lack of systematic risk framing that connects geopolitical indicators to airspace exposure in real time.
For airlines operating through the Taipei FIR, the planning calculus is straightforward in retrospect: Lai Ching-te's inauguration was on May 20. Beijing had established a clear behavioral pattern of large-scale military exercises following major Taiwan political events. The August 2022 drills followed Pelosi's visit by less than 24 hours after announcement. A risk-aware operator tracking geopolitical loading conditions on the RCAA had, in theory, 18 weeks from the January 13 election result to elevate contingency planning for the May 20–25 window.
The deeper structural problem is the deteriorating NOTAM compliance trend. When the first modern encirclement exercise (August 2022) was issued with ~48 hours notice, it was already far below the ICAO Annex 15 standard. By May 2024 that window had compressed to approximately 24 hours. If this trend continues — and the pattern gives no reason to assume it will reverse — a future exercise may be announced with hours of notice, or none at all, with exercise zones already active at the time of publication. At that point, the NOTAM system is functionally useless as a planning tool for this airspace, and proactive geopolitical risk modeling becomes the only viable mechanism for operational preparedness.
This retrospective analysis examines signals present in public data before the event. It is provided for educational context only and does not claim predictive capability for future events.
From January 13, 2024 onward, A retrospective analysis suggests FlySafe's indices may have indicated the Taipei FIR (RCAA) as entering an elevated-risk loading condition following Lai Ching-te's election victory. The system cross-references known political trigger events — inaugurations, high-profile diplomatic visits, legislative milestones — against a behavioral model built from prior PLA exercise episodes. By early May 2024, with inauguration week approaching, the RCAA risk score may have reflected escalation to HIGH, with a specific advisory window flagging May 19–26 as the highest-probability period for airspace disruption activity. Subscribers could have observed proactive alerts recommending contingency routing review, fuel planning adjustments for extended track miles, and passenger disruption pre-positioning — not at 24 hours notice, but weeks in advance. The 84 cancellations that caught the industry by surprise on May 23 were, from a risk-signal perspective, one of the most foreseeable disruption events of 2024.
Political calendars are airspace calendars. Inaugurations, elections, and high-profile visits in politically sensitive regions must be mapped directly onto FIR risk timelines. A confirmed inauguration date is a confirmed risk window.
Behavioral pattern modeling outperforms NOTAM monitoring. When a state actor has demonstrated willingness to issue NOTAMs with 24 hours notice — or less — NOTAM monitoring is reactive by design. Pattern-based risk scoring of the political environment provides the only meaningful lead time.
All-sides encirclement eliminates in-FIR contingency routing. The 4-sided exercise structure of Joint Sword 2024A means standard contingency planning (reroute via the unaffected sector) fails entirely. Contingency plans for RCAA must assume complete FIR exclusion and pre-position alternative transoceanic routing for all affected city pairs.
NOTAM compliance is deteriorating in high-risk corridors. The 7-day ICAO Annex 15 standard is structurally violated by PLA exercise NOTAMs around Taiwan. This is not an administrative oversight — it is a persistent pattern across three episodes spanning 2022–2024. Risk models for the region must be built on the assumption that regulatory notice windows will not be honored.
Sources
- — Taiwan Civil Aeronautics Administration — NOTAM and Flight Disruption Data, May 2024
- — IATA — Cross-Strait Airspace Risk Update (2024)
- — Reuters — "China Launches Military Drills Around Taiwan After Inauguration of New President," May 23, 2024
- — Nikkei Asia — "84 Flights Cancelled as China Drills Encircle Taiwan," May 23, 2024
- — South China Morning Post — "Joint Sword 2024A Exercise Analysis: Scale, Scope, and Strategic Signaling," May 2024
- — ICAO Annex 15 — Aeronautical Information Services, Standards for NOTAM Publication (7-day hazardous activity requirement)
- — PLA Eastern Theater Command — Official Statements and Exercise Announcements, May 20–24, 2024
This is a retrospective analysis of publicly documented events. FlySafe's prediction system was not operational during this event. All information is sourced from public records, aviation authority publications, airline statements, and open data.