United Expects 147 Boeing MAX 10 Jets After 2027 Despite Finished Flight Tests

147 aircraft now define the scale of United Airlines’ Boeing 737 MAX 10 delay. Of the carrier’s 167 firm commitments as of June 30, United expects 147 to arrive after 2027, leaving only 20 deliveries in 2027 and none in the second half of 2026.

That is a significant change from the underlying contract schedule, which placed three aircraft in the second half of 2026, 44 in 2027 and 120 after 2027. United’s current expectations therefore move another 27 MAX 10s into the post-2027 period. The later share has risen from 71.9% of its firm order to 88.0% nearly nine out of every 10 aircraft.

The revised timing illustrates an important distinction in aircraft certification: finishing planned flight tests does not authorize customer deliveries. Boeing said the MAX 10 completed its planned flight-test campaign on July 28 after 976 flights and more than 2,060 flight hours. Its program update described flight testing as complete, but also showed that substantial review work remained.

Flight tests produce data; certification must close the findings

A flight-test campaign demonstrates aircraft behavior and validates systems under defined conditions. The resulting measurements, observations and compliance findings must still be evaluated alongside design documentation and safety analyses. Boeing reported that development-assurance review 4 was 60% complete and system-safety assessments were 32% complete.

Those percentages do not establish a final approval date, and they should not be treated as a simple countdown. Different certification work packages can vary substantially in complexity, required documentation and regulator involvement. Findings can also generate follow-up analysis or design work. The Federal Aviation Administration had not granted final MAX 10 approval as of August 23, although Boeing continued to target certification in 2026.

The recently approved MAX 7 offers a useful indication of the breadth of work involved without establishing a timetable for the larger MAX 10. In its MAX 7 certification statement, the FAA said its review covered flight controls, system-safety assessments, human factors, flight-crew alerting and other safety-critical areas. The agency also required testing, design changes and further analysis before issuing that aircraft’s amended type certificate. The MAX 10 remains a separate certification decision.

A delivery delay becomes a fleet-integration problem

For United, the consequences extend beyond moving dates in a fleet plan. The airline had developed premium transcontinental plans around the MAX 10 years ago and acquired hundreds of lie-flat seats for it. United CEO Scott Kirby said those seats do not fit other aircraft. The carrier has since assigned an Airbus A321neo subfleet to that premium role and has not disclosed the final MAX 10 cabin layout or route plan.

That illustrates why prolonged aircraft delays can create costs even before an airline takes delivery. Cabin equipment is engineered and certified around a particular installation, including physical interfaces and aircraft-specific requirements. Fleet substitutions can therefore require different interiors, training, maintenance planning and route assignments rather than a straightforward transfer of equipment from one type to another.

United currently expects its first MAX 10s in summer 2027, but its delivery estimates can change as supplier information and program assumptions evolve. FAA approval would clear a central regulatory gate, yet Boeing would still need to prepare aircraft for customers and support airline entry-into-service work.

A separate labor deadline adds another uncertainty around program execution. Approximately 17,000 Boeing engineers and technical workers rejected proposed contracts and authorized union leaders to call a strike after the agreements expire October 6. No additional talks were scheduled following the vote. A labor agreement could remove that risk; a work stoppage or a longer regulatory review could put further pressure on delivery timing.

For now, Boeing has completed the visible flying phase, but the less visible safety-analysis and development-assurance work remains unfinished. United’s schedule puts the practical consequence in concrete terms: only 20 of its 167 MAX 10 commitments are expected to arrive by the end of 2027.

By Thomas Caldwell — AMI’s senior editor for mechanical and mobility engineering, covering vehicle electronics, systems integration, electrification, chassis systems, propulsion, and safety policy.