Boeing has been putting the new Boeing 777X test aircraft through its paces, taking off and landing multiple times in different conditions to ensure that the new prototype can perform as designed. One of these tests is the ‘wheel braking trial’, to see if this huge airframe can stop during an aborted takeoff.
What is the testing process for the 777X?
If you don’t know, the Boeing 777X is the new version of the Boeing 777 line, much like the different versions of the Boeing 737 and 747. There are actually two variants of aircraft:
- The 777-8 can carry 384 passengers in two classes to a range of 8,730 nautical miles / 16,170 km
- The 777-9 can carry 426 passengers in two classes to a range of 7,285 nautical miles / 13,500 km
The different versions are designed for different routes, which you can read about here.
So far, Boeing has only built one Boeing 777X test aircraft, a 777-9 tail number WH001, which is being used for electronics, taxi tests, and first flight. After the first flight, the aircraft will be used to check avionics and related system, brakes, flutter, icing, stability, control, and low-speed aerodynamics post flying.
There will be another three other identical Boeing 777-9 aircraft built, WH002 to test auto-landing, ground effects, stability, and controls. WH003 to test auxiliary power unit, avionics, flight loads and propulsion performance. Finally, WH004 will test the environmental control systems, extended twin-engine operations, noise, and general functionality and reliability.
None of these aircraft have anything even resembling a passenger plane onboard. They don’t have seats, they don’t have cabins or even bathrooms. They are purely hollow shells designed to test all the functional parts of the airframe. They are loaded with heavy weights, however (likely water), to simulate a full load of passengers and cargo. But we can’t say for sure if they are fully loaded in fuel as they are not performing any long-distance flying (that test is sure to come).
What happened in today’s test?
At the Boeing test runway in Washington state, the brand new Boeing 777X performed an abort takeoff test.
The aircraft powered up both GE9X engines and powered up the runway to reach a speed that would be close to required to begin lifting off. The pilots then slammed on the brakes and caused the aircraft to come to a halt.
You can watch the video below.
We caught the #Boeing 777x performing a rejected takeoff test demonstrating acceleration, and then abruptly stopping the plane using brakes only.
Judging by the video the pilots did not engage reverse thrusts and purely wanted to ensure that the brakes could stop the plane themselves. Also right at the end of the clip, you may see a tire burst.
What is the next test?
Boeing has been reluctant to reveal any details of its testing process and when exactly each airframe will be tested and for what. The company said it did not want to rush certification, especially in light of the re-certification of the Boeing 737 MAX.
“We’re taking the lessons learned from the 737 MAX and applying them to the 777X to ensure we are as prepared as possible for 777X certification,” Boeing said to FlightGlobal “Given the unknowns around development programs, as well as the certification process, we do not want to be overly specific about hours of testing or timing.”
The next tests likely are shorter runway stops when landing, and aborting landing tests. Additionally, Boeing will need to do cold-weather tests, high altitude landing/take-off (such as conditions at Mexico City airport), hot weather and long-distance flying.
But optimists in us believe that if all goes well, we should be flying on the Boeing 777X by next year.
What do you think of these tests? Let us know in the comments.