Latest In Aviation

World’s Largest Jet Engine, GE Aviation GE9X, Makes Debut Flight Touting 100K Pounds Of Thrust

Latest In Aviation

Latest In Aviation

GE has announced that it has a new jet engine that has lifted off for the first time. The maiden flight of the GE9X jet engine happened on March 13 and it was hung under the wing of GE Aviation‘s 747 flying testbed in Victorville, California for the flight. One glance at the images and you can see just how massive the new GE9x engine is compared to the legacy engines that are slung under the wings of the 747.

GE is designing the massive engine specifically for the Boeing 777X aircraft and the engine makes 100,000 pounds of thrust. The engine flew for over four hours on its maiden flight and was able to complete the entire test card and was validated for operational and functional characteristics. That means that the engine testing can progress in future flights.
“The GE9X and Victorville teams have spent months preparing for flight testing of the engine, and their efforts paid off today with a picture-perfect first flight,” said Ted Ingling, general manager of the GE9X program at GE Aviation. “Today’s flight starts the beginning of the GE9X flight test campaign that will last for several months, allowing us to accumulate data on how the engine performs at altitude and during various phases of flight.”

GE notes that certification testing for the massive jet engine began in May 2017. In addition to the flight test, the engine also recently completed its icing tests at GE Aviation’s facility in Winnipeg, Manitoba, Canada. Currently, the engine is undergoing crosswind testing at the Peebles Test Operation in Ohio. GE expects that the engine will receive final certification in 2019.

The gigantic GE9X engine has 700 orders already on the books and will have the largest front fan at 134-inches in diameter of any jet engine with a composite fan case and 15 fourth generation carbon fiber composite fan blades. The engine has a 27:1 pressure-ratio 11-stage high-pressure compressor and a third-generation TAPS III combustor for efficiency and low emissions.

Boeing 737 Max 9 Cleared for Service

Latest In Aviation

Latest In Aviation

LATEST IN AVIATION – The Boeing 737 Max 9 has received its U.S. Federal Aviation Administration amended type certificate, clearing it for commercial service with launch customer Lion Air of Indonesia, Boeing announced Friday. The certification marks the culmination of an 11-month flight-test program involving two airplanes.

Designed to carry 220 passengers to a range of 3,550 nm, the Max 9 becomes the second 737 Max variant to win certification. It follows the program’s baseline Max 8, which has collected most of the orders for the four Max variants. Although Boeing declines to break down order numbers by model because, it says, some customers retain rights to move from one to the other, the Max 9 has drawn far fewer initial commitments than has the Max 8 or the more recently launched Max 10—the largest of all the Max variants.

Although industry analysts expect the Max 10 to “cannibalize” the Max 9’s market to a degree, Boeing Commercial Airplanes marketing vice president Randy Tinseth insisted at the recent Singapore Airshow that while a small proportion of the new orders and commitments for the Max 10 represent transfers from Max 9s, most were completely new, suggesting that the Max 10 has not significantly compromised demand for the smaller variant.

“We see a place for both the 9 and the 10, depending on the customer,” said Tinseth. “The 10 plugged a hole that we had, and that hole was we didn’t have as many seats as the [Airbus] A321.”

Addressing the demand mix for the Max family, Tinseth estimated that between 60 and 65 percent of orders will go to the baseline Max 8, 20 to 25 percent to the Max 9 and 10 and roughly 10 percent “on the lower end of that market,” namely the Max 7.

Crucially, Tinseth did not separate demand estimates for the Max 9 and Max 10, the smaller of which leasing company Avolon said would find itself all but squeezed out of the market in a report that it issued last summer.

CAN AN AIRPLANE TAKE OFF ON A MOVING RUNWAY?

Latest In Aviation

Latest In Aviation

THIS QUESTION IS probably as old as the airplane itself. It goes something like this:

An airplane has a takeoff speed of 100 mph (I just made that number up). What if it gets on a super giant treadmill that moves backwards at 100 mph. Could a plane on this giant treadmill take off or would it just sit there moving at 0 mph?

The first question a reasonable person would ask is “Where do you get a giant plane-sized treadmill that goes 100 mph?” Yes, that is indeed a good question—but I won’t answer it. Instead, I’m going to give this question the best physics answer I can.

Before I do that, I should point out that others have also answered this question (not surprising since it’s super old anyway). First, there is the MythBusters episode from 2008. Actually, they didn’t answer the question—they did the question. The MythBusters made a giant conveyer belt with a plane on it. It was awesome. Second, there is the xkcd answer to this question (also from 2008).

Now you get my answer. I will answer with different examples.

A Car on a Conveyer Belt
This isn’t so difficult. What if I put a car going 100 mph on a conveyer belt that is also going 100 mph? It would look like this (something like this):

Really, there is probably no surprise here. The car’s wheels would roll at 100 mph as the treadmill (or conveyer belt) moves back at 100 mph so that the car remains stationary. Actually, here is a slightly cooler example (with the same physics).

Here is an experiment (also from the MythBusters) in which they shot a ball at 60 mph out the back of a truck also going 60 mph. You can see that the ball remains stationary (with respect to the ground).

Super Short Takeoff
There is a plane from Alaska that takes off in a very short distance.

How does this work? I’ll give you a hint—there is a very strong wind blowing into the front of the plane. Without a headwind, this wouldn’t happen. But if you think about it, this short take off is very much like the car on the treadmill. For a plane, it doesn’t drive on the ground, it “drives” in the air. If the plane has a takeoff speed of 40 mph and is in a 40 mph headwind, it doesn’t even need to move at all with respect to the ground.

Plane on a Conveyer Belt
Yes, it takes off. A plane can take off from a runway moving in the opposite direction? But why? It’s because the wheels on a plane don’t really do anything. The only function for the wheels is to produce low friction between the aircraft and the ground. They don’t even push the plane forward—that is done by the propeller. The only difference when launching a plane on a moving runway is that the wheels will spin at twice the normal speed—but that shouldn’t matter.

So the plane on a treadmill works, but how about a case where the plane wouldn’t take off? What if the plane was more like a glider with motorized wheels? On a normal runway, these motorized wheels would increase the speed of the glider until it reached takeoff speed. But if you put this on a moving runway, the wheels would spin at the right speed and cancel the motion of the treadmill so that the plane would remain motionless and never reach the proper speed for a launch.

OK, so that is the answer to everyone’s favorite question. But don’t worry, this answer won’t stop the endless discussion—that will live on forever.


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