According to Aviation Week, Boeing has resumed flight testing of the smallest member of the 737 MAX family, the 737-7, marking the beginning of the final stretch of long-delayed certification work for the 737-7 and 737-10 variants. The move follows years of setbacks caused by the need to redesign the engine anti-ice (EAI) system and the associated nacelle inlet structure.
The only 737-7 test aircraft, designated 1E001, returned to the skies on October 6 after spending more than a year in storage at Moses Lake, Washington. On August 11, it was ferried to Boeing Field in Seattle, where most of the manufacturer’s development and flight-testing programs take place. At the same time, flight testing of the stretched 737-10 has also intensified: aircraft 1G002 flew from Seattle to Roswell, New Mexico, on October 7 to begin a new phase of certification work, while the other two test units, 1G001 and 1G003, have also resumed regular flights.
As Aviation Week reports, aircraft 1G001, which first flew in June 2021, has now accumulated nearly 1,100 flight hours over 319 sorties. Aircraft 1G002 has logged 424 hours across 150 flights, while 1G003 has reached 253 hours over 80 missions. This increase in activity comes less than a month after Boeing CEO Kelly Ortberg confirmed that the company is closing in on a finalized EAI redesign and that both variants remain on track for certification and deliveries in 2026.
Speaking at the Morgan Stanley Laguna Conference in September, Ortberg said that Boeing has made “significant progress on the design of the engine anti-ice system” and is “working closely with the FAA on the certification tasks.” He recalled that certification had been pushed from the end of 2025 into next year but expressed confidence that the aircraft would be certified and delivered in 2026.
The issues with the original EAI design centered on the vulnerability of the nacelle’s composite inlet to thermal damage, prompting a full redesign. In the meantime, Boeing has implemented operational limitations on the EAI system for the in-service 737-8 and 737-9 until the new inlet can be retrofitted across all fleets.
The 737-7 was first rolled out in February 2018 and was initially expected to enter service with launch customer Southwest Airlines in 2019. The larger 737-10, unveiled in 2017, was originally scheduled for 2020 entry into service but faced multiple delays due to the COVID-19 pandemic and heightened regulatory scrutiny following the 737-8 accidents. Now, nearly a decade after the program’s launch, Boeing is finally entering the closing stages of testing, aiming to bring the last two MAX variants into commercial service in 2026.
