One of four Boeing 777X test aircraft has been flown from Seattle to Fairbanks, Alaska, for testing in extreme cold conditions as part of its certification program.
Aircraft need to be tested to examine how extreme cold affects various parts of the aircraft.
For example, metals shrink at different rates, while lubricants can lose their viscosity, creating wear problems in moving parts.
One of the tests involves shutting down the aircraft for 24 hours and then performing a cold start.
The scope of the tests includes: engine and APU startup after cold dive; thrust reverser testing in snow; verification of systems behavior at extreme temperatures; and aborted takeoff.
Last week, Boeing announced the delay of the 777X program to accommodate certification changes and customer requests to delay deliveries due to COVID.
The aircraft has been ordered by airlines including Emirates, Qatar Airways, Etihad Airways, Lufthansa, Singapore Airlines, Cathay Pacific Airways, British Airways and All Nippon Airlines.