Vietnam's Summer Flight Delays: Nearly One in Four Ran Late in June — and It's Still the Best June in Three Years
Nearly one in four flights in Vietnam left late this June. Sounds bad — until you look back: last June the on-time rate was just 56%. The other side of this delay wave is the slow recovery from an engine-recall crisis that once took a fifth of Vietnam's fleet out of the sky.
[Vietnam's Summer Flight Delays: Nearly One in Four Ran Late in June — and It's Still the Best June in Three Years]
A number made the rounds in Vietnamese media this week: the country's flight punctuality rate has fallen to 75%. The figure is real, but it needs context. It measures on-time departures for June alone — not the full year.
According to statistics released in mid-July by the Civil Aviation Authority of Vietnam (CAAV), the industry-wide on-time rate in June was 75.7% — nearly one in four flights left late. Compared with March through May, when the rate climbed from close to 80% to 87%, June was a clear slump.
Zoom out, though, and the June dip turns out to be an annual event. In June 2024, the industry rate fell below 70%. June 2025 was worse still: just 56%. For three years running, June's on-time rate has dropped by roughly ten percentage points from May. Carriers add flights for the summer peak, schedules tighten, and delays multiply. It's a seasonal ailment.
Line up the three Junes — under 70%, then 56%, now 75.7% — and this year is actually the best June in three years. So what happened in the two years before?
The answer: not enough planes. In late 2023, engine maker Pratt & Whitney confirmed manufacturing flaws in one of its engine models, recalling over a thousand units worldwide. Airbus A321neo jets powered by the engine were grounded in droves, and both Vietnam Airlines and Vietjet had dozens affected. By mid-2024, Vietnam's flyable fleet had shrunk by roughly a fifth from the year before. As of late last year, more than a tenth of the commercial fleet was still parked, waiting for engines.
With a fifth of the fleet gone and passenger demand still growing, carriers had one option left: squeeze more flights out of the planes they still had. CAAV data show that in the first half of 2024, some airlines pushed monthly flying hours per aircraft up by 30%. Each plane flew more legs per day, ground time was cut to the bone, and schedules had no slack — if the first flight of the morning ran late, every later flight on that aircraft ran late too. That's why "late-arriving aircraft" has topped the delay-cause table for years: it accounted for nearly 60% of all delays this June, and close to 70% at the worst of it last June. Weather, by comparison, caused less than 7%.
Once you see that mechanism, the airline rankings read differently. The steadiest performer this June was VASCO — a Vietnam Airlines subsidiary flying simple short hops like Ho Chi Minh City to Con Dao — at 90%. Vietjet flew more flights than anyone, with an on-time rate just above 70% and the most delays in the industry; at the worst point, in June 2024, one in two of its flights ran late or was cancelled, and its on-time rate for the first half of 2025 barely cleared 50%. A small fleet is no guarantee of punctuality — Bamboo Airways and Vietravel also sat near the bottom this June — but an operation that runs its aircraft to the limit also posts the biggest delay numbers. High utilization is what makes budget fares cheap; by the same mechanism, it's also what makes delays likely. When you buy a cheap ticket, you're buying the delay odds along with it.
Full-service carriers didn't escape the crisis either. Beyond its A321neos, Vietnam Airlines also had A350s parked for engine checks, and it cancelled more flights in June than any other carrier. Curiously, a mid-June report by aviation analytics firm Cirium ranked Vietnam Airlines among the top three most punctual carriers in Asia-Pacific — the highest-ranked full-service airline on the list. The difference is methodology: Cirium counts arrivals, where a flight is on time if it reaches its gate within 15 minutes of schedule, and Vietnam Airlines scored about 88%. The CAAV counts departures, over a different period. The two sets of numbers can't be compared directly.
This year's rebound comes down to planes returning to service: repaired engines are coming back batch by batch, the long-grounded A321neo count has come down, and Vietjet took delivery of more than twenty new aircraft late last year alone. The CAAV is also squeezing more out of the two biggest airports, raising hourly runway caps at Hanoi's Noi Bai and Ho Chi Minh City's Tan Son Nhat through the National Day holiday in early September. The on-time rate has climbed out of last year's trough accordingly.
Still, raising hourly caps on existing runways only goes so far. Real capacity arrives at the end of the year, when Long Thanh International Airport aims to welcome its first commercial flight on December 1 — finally giving Tan Son Nhat an outlet. Until then, two things are worth knowing if you're flying in Vietnam this summer. First, your rights: under rules that took effect in July, if a flight is delayed more than four hours or cancelled for reasons attributable to the airline, passengers can request a refund — within 21 days by cash or bank transfer, or 45 days for credit card payments. Second, booking: most delays cascade from late-arriving aircraft, so the later in the day your flight, the higher the odds it inherits someone else's delay. Morning flights are the safer bet.
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