Boeing uses Mexico's Toluca airport for critical high-altitude tests on delayed 777X

Boeing’s "Hot & High" tests with a 777-9 model at Toluca were part of efforts to secure FAA certification—a process made more rigorous after two fatal crashes involving the Boeing 737 MAX led regulators to scrutinize new models more closely. As of mid-2025, type certificates for the MAX 7, MAX 10, and 777X remain pending.

While Toluca is not commonly used by Boeing for flight testing—such work often takes place at even higher airports like El Alto International Airport in La Paz, Bolivia—it has been selected occasionally when specific program needs arise. For instance, Airbus also tested its A330-900neo at Toluca in March 2024 as part of broader trials that included stops at La Paz. Both the A330neo and the Boeing 777X are updated versions of older widebody designs featuring improved wings and engines.

El Alto International Airport sits at an altitude of over 13,000 feet and is regularly chosen by manufacturers like Boeing and Airbus for high-altitude performance assessments. Such extreme conditions can reveal limitations in payload capacity or handling that may not appear elsewhere; past incidents there have prompted temporary restrictions on certain aircraft types due to safety concerns.

Within the United States, while most testing occurs near sea level or at moderate elevations like Colorado Springs (6,187 feet), these sites do not match the environmental extremes found abroad. In early 2024, one prototype of the 777X performed multiple takeoffs and landings at Colorado Springs before moving on to Toluca for further evaluation.

FAA certification for the Boeing 777X is expected later in 2025 with entry into commercial service anticipated in 2026; however, this timeline could change if regulatory hurdles persist. To date, all firm orders for the model come from international carriers—primarily Emirates and Qatar Airways—with no buyers from North or South America.

Currently, Boeing continues production only of passenger variants of its MAX series (specifically MAX 8s and MAX 9s) along with deliveries of freighter versions of other models while preparing for eventual introduction of the certified passenger-ready version of the 777X.