Even as the number of Vietnamese air passengers jumped by 29 percent year-on-year to nearly 19 million in the first six months, the number of delayed flights too increased, the Civil Aviation Authority of Vietnam said.
CAAV's figures released at a meeting last week showed more than 20,000 flights, or 15.8 percent of the total number, were delayed. That represented a 0.8 percentage point rise from a year ago.
The number of canceled flights too increased slightly to 772.
Low-cost Jetstar Pacific recorded the highest rate of flight delays and cancellations at 20.7 percent. It was followed by another budget carrier, VietJet Air, and Vietnam Airlines with 16.4 percent and 15.3 percent.
The carriers blamed weather conditions, technical faults and airports' insufficient infrastructure among other reasons for the delays and cancellations.
CAAV chief Lai Xuan Thanh was quoted as saying that passengers complained mostly about delays or cancellations caused by airlines moving them around to fill up flights, especially at night.
CAAV has ordered relevant agencies to step up oversight of night flights to limit the practice, he said.
Vietnam Airlines and VietJet Air, which dominate the domestic market, promised to reduce their delay and cancellation rates to 10 per cent and 12 percent by the end of this year.