Over ~1000km Air is pretty competitive with HSR even in China.
+since we're talking China, sometimes you don't have a choice really, and buy whatever ticket you still can buy.
COMAC C919
- Thread starter Deino
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+since we're talking China, sometimes you don't have a choice really, and buy whatever ticket you still can buy.
they're not lego pieces that swap together easily. all the monitoring and control systems for the turbofans are highly integrated and customized into the flight instrument panels, auto pilot, wiring harness, hydraulics and a multitude of other systems on the aircraft. This is one reason for the Boeing 737 Max fiasco - they wanted to change the engine to a new heavier, but more efficient one without significantly redesigning the plane(which will require a long recertification process). So Boeing tried some software hacks to account for the new weight balance, which we now know had terrible results.
TerraN_EmpirE
Tyrant King
Bit of an over simplistic explanation. Boeing did want new engines. The new engines are of a larger diameter than the older ones so new nacelles were needed. Those nacelles did shift the weight but also generated more lift. Boeing wanted to copy a feature found in Airbus aircraft. Where the cockpit of a A300 is identical to that of an A380. They use software so that each of the Airbus birds is identical in flight controls. So if you are certified on one Airbus you are certified on them all. It’s just that Boeing apparently didn’t have the same success. They wanted to introduce this into the new 737 Max so Pilots could easily go from 737 NG to MAX.
Totally wrong
By John Cox
Why did MCAS trim the nose down? The central design goal of the MAX design was to improve fuel efficiency. New engines could do that, but required bigger initial compressor sections, known as a fan. This required the engine to be move forward and raised to keep the necessary ground clearance while taxiing.
One consequence was the reduction in the nose pitching down during lightweight stalls with the airplane loaded as far aft as allowed. The FAA and engineers found it needed help the nose pitch down during these conditions. MCAS was the solution.
TerraN_EmpirE
Tyrant King
No Vincent not totally wrong. It’s your understanding of my post that has failed.
Boeing did want new engines more efficient ones. But to mount them they needed to compensate for the larger size as the 737 is pretty low to the ground already and the engines are under slung like most airliners. So they needed the new nacelles. Those engines are heavier and the nacelles moved the weight and being longer generated lift. This lift and weight altering the flight characteristics. But Boeing had tried to sell the Airlines on an easy transition. That’s where MCAS comes in. It was supposed to be the secret sauce.
A fly by wire system designed to enable the MAX to emulate the NG. But it became the Achilles heal.
In essence we were and are saying the same thing.
Boeing did want new engines more efficient ones. But to mount them they needed to compensate for the larger size as the 737 is pretty low to the ground already and the engines are under slung like most airliners. So they needed the new nacelles. Those engines are heavier and the nacelles moved the weight and being longer generated lift. This lift and weight altering the flight characteristics. But Boeing had tried to sell the Airlines on an easy transition. That’s where MCAS comes in. It was supposed to be the secret sauce.
A fly by wire system designed to enable the MAX to emulate the NG. But it became the Achilles heal.
In essence we were and are saying the same thing.
HereToSeePics is correct that Boeing wanted to use the latest and greatest engines to compete against Airbus but was unwilling to spend the money (used to buy back stocks instead) to design a new plane and go through the certification process. One of MCAS's purpose is to prevent stalls by forcing the plane to point down because 737Max like to till its nose up by itself (without any input from the pilots) at certain flight regiments.
TerraN_EmpirE
Tyrant King
Correct Boeing was trying to compete vs the A320 NEO. Which was a re-engineering of the A320 series. But they didn’t do so entirely on the cheap. It did require technology upgrades and redesign. The reason it points up is both the weight and the lift.
The engines pass air through them.