The global grounding of Boeing 737 MAX aircraft is causing major operational headaches for many Asia-Pacific airlines, as they scramble to adjust their schedules to replace MAXs.

Several Asian carriers have MAX family aircraft in their fleets—in some cases just a handful, but still proportionally significant. Airlines have had to cancel some flights and reshuffle their fleets to cover for the MAXs. Even some carriers that have not yet received their first MAXs are altering their plans.

The groundings follow the crash of an Ethiopian Airlines 737 MAX 8 near Addis Ababa on March 10, killing all 157 people onboard. Many countries suspended MAX operations in the days following the crash, and this effectively became a global action March 13 when FAA ordered groundings and Boeing made a similar recommendation.

Indian LCC SpiceJet operates 12 MAX 8s, and was among those carriers canceling some flights. The airline said it is “optimizing” the use of its Boeing 737NGs and Bombardier Q400s. It is also “evaluating options for augmenting capacity in the coming days through a mix of additional flights and aircraft inductions.” The carrier did not elaborate where it may source extra aircraft from. It predicted operations would return to normal soon.

While Indian carrier Jet Airways has five delivered MAX 8s, these were already grounded because of lease payment defaults.

Singapore Airlines (SIA) subsidiary SilkAir has six MAX 8s in its fleet. Most of its MAX routes will be covered by SilkAir 737-800s, Airbus A320s and A319s. However, the carrier has still had to cancel three return flights per day on the busy Singapore-Kuala Lumpur route on March 13-15, and two flights on its route to Yangon, Myanmar on March 17.

To help compensate for the reductions, parent SIA will operate extra flights during these periods. SIA will operate one additional Airbus A350 return flight per day on the Kuala Lumpur route. It will also add a flight on the Yangon route.

Indonesia’s Lion Air operates 10 737-8s out of a total fleet of about 121 aircraft. The Jakarta Post reports Lion Air will use other aircraft in its fleet to replace the -8s. Joint venture Thai Lion Air has three 737-9s, and during the grounding it will operate its -9 routes with 737-900ERs, 737-800s and Airbus A330s.

Fiji Airways, which operates two MAX 8s, said it “has the capacity to manage the change of aircraft type” on the -8 routes. The carrier intends to operate its full schedule, although it said some flight times may be changed. It will use its 737NGs and A330s to cover for the -8s.

Korean Air does not operate any MAX aircraft yet, although it is scheduled to take delivery of six MAX 8s this year. The first of these is planned for May, but the carrier has decided to proactively switch to different aircraft types on the routes planned for the initial -8s. The aircraft were scheduled to be deployed on routes to Japan and China.

The airline said it will not operate the MAX 8s until the aircraft’s safety is assured. If the MAXs are cleared before May, Korean will review its deployment plans again.

Adrian Schofield,