lørdag 4. januar 2020

B777X flyr antakelig i år - Curt Lewis

2020 Should See The Boeing 777X Take Its First Flight

The Boeing 777X is very likely to take its first flight this year, despite missing the original flight testing date back in 2019.


Boeing is hopeful to be flying the 777X early this year. Photo: Boeing.

Why has the Boeing 777X not yet flown?
If there is one news story that we are disappointed we never got to write in 2019, it would be the first flight of the Boeing 777X.

Last year, experts and aviation commentators alike assumed that the new airframe, which had already completed taxi tests and grounded electrical tests, would be taking flight just before Christmas.

At the Paris Air Show, Boeing officials remarked that "We still expect to have the airplane flight test this year, with an entry into service next year,"

However, problems with the 777X's new massive GE9X engine (which has a similar diameter of a Boeing 737) pushed back the flight a few months and into 2020.

"The 777X program is progressing well through pre-flight testing. While the company is still targeting late 2020 for the first delivery of the 777X, there is a significant risk to this schedule given engine challenges, which are delaying first flight until early 2020" Boeing said to Flight Global.

Whilst the engine has been the primary cause of the delay for the 777X flight test, there are a few other issues worth mentioning during the 777X production.


The Boeing 777x has completed a slow taxi test. Photo: Boeing

What other issues might impede the test?
In September, a static 777X test fuselage was undergoing an 'ultimate load' experiment when the pressure caused a rip across the bottom of the aircraft.

This test is a dramatic weighted experiment to ensure that the aircraft remains whole under extreme conditions, which in this case was 1.5 times more force than would be experienced in normal flight (A force of 3.75 G as opposed to the normal force of 1.3 G).

Boeing engineers pulled up the wing of the aircraft 28 feet from the normal resting position, whilst at the same time forced the main fuselage of the aircraft down.

This buckled the frame under the wing and dramatically ripped apart the belly of the aircraft. The entire test fuselage was written off and Boeing under-reported this until November (At the time saying that only a door had fallen off).

As the test had reached 99% of the goal stress point, it was determined that with a little bit of additional engineering around that area affect the aircraft would be safe to fly.

"What we've seen to date reinforces our prior assessment that this will not have a significant impact on the design or our preparations for the first flight." - Boeing spokesman Paul Bergman to the Seattle Times in November.

When will the first flight take place?
It is too early to suggest when a first flight will take place, but for three reasons I believe the 777X will fly in the first half of 2020.

The first is that they no longer have any more significant tests to perform (and fitted the 777X's with their main engines back on the 17th of December). They have the aircraft ready to fly and only need to wheel it down at speed and do a few laps (a big oversimplification but you get the idea).

Secondly, Boeing needs a win right now. With a new CEO and big expectations from shareholders. the pressure is on to get this new aircraft in the air and rebuild the brand reputation.

Lastly, with deliveries expected to be in 2021, Boeing needs to complete a certain number of hours of flight tests to have their type certified. It depends on aircraft to aircraft, but using Airbus as a comparison they flew their A350-1000 type for 1,600 hours in a variety of different conditions. Thus Boeing will need to start flying as soon as possible to build up those hours to meet their 2021 delivery deadline.

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