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[MerrilGordon]

Hmmm . . .
Cessnas and 787's. Greg asked if a 787 would outrun a 727. Probably in jest, but darned if I know. I did ask one of our aero guys how fast a 787 would fly and got this response:

Hi Merrill

Good questions!

Maximum Mach number on airplane is around M=0.97. The airplane is fully controllable and stable at least to this Mach number, and the structure can withstand the high dynamic pressure.

For Mach numbers over 0.87 the drag rise becomes very steep and it is not very economical to fly there (using more fuel and you would not make the range). So operational Mach number for 787-8 is between 0.85 and 0.86. The drag rise is due to formation of strong shockwaves on the wing.

With different wing design it is possible to have higher operational Mach number. Remember the Sonic Cruiser couple years ago? Mach was about 0.95. Supersonic transports (such as Concorde) fly at M = 2.0 - 2.4 (but with a very different wing shape).

747-400 flies around Mach 0.86, 767 and Airbus A330/340 aircraft fly around 0.8 - 0.82. A380 supposedly flies at M0.85. 777 flies at M 0.84.
Smaller aircraft (737, A320) fly at Mach 0.78 - 0.80.


Hope this helps

Regards

Paul Vijgen
787 - High-Speed Aerodynamics


Interesting I think,
Merril

[matt]

Interesting info there Merril, what rumors are there inside Boeing? Was the Sonic Cruiser just "smoke and mirrors" to direct attention away from the A380 maybe? and why hasn't Boeing decided to compete directly against it with the 747 X etc? Are 777ER etc "hub busters" really the future as Boeing see s it .......or are there rumors of something even bigger to come? maybe even revolutionising the aviation industry as much as the 747 did back in the '70s. The A380's introduction although big won't be anything like the 747's
I hope Boeing s got something...............
So whats the inside word?

[MerrilGordon]

The word I got about the Sonic Cruiser was that technology wasn't the problem. A Boeing VP type of guy said at the launch of the 787 the airlines determined competition between themselves would prove to be too difficult an economic hurdle to overcome the higher operating costs of a sonic cruiser. In the end they thought all of the neat technical stuff incorporated into a slower airplane would be of better value. Economics killed that airplane I guess. . . . at least what's what I'm told . . . The 787 incorporates many of the sonic cruisers features such as composite fuselage, no air driven pumps (all electric now), and many others.

I do think Boeing has been quite lax about producing new airplanes. It's been about ten years since they designed the 777. Regarding smaller airplanes versus larger ones, and pardon me as I'm not a true expert here, airlines like larger planes as they claim the hub and spoke system is more economical. But passengers prefer direct flights without the hassle of layovers and luggage transfers. That's the argument for smaller airplanes. Boeing seems to think passengers will win on this issue so they passed on an A380 competitor and went for a more efficient replacement for the 767. Note that Airbus has finally had to counter Boeing's 787 offering with a totally new airplane, the A350, as it was quickly becoming apparent to them that the 787 would have killed any equivalent sized offering they already produced.

Regarding some kind of 747X, Boeing has funded numerous trade studies and keeps hitting a wall they're not willing to climb over yet. The 747 has reached its growth limit. They could design and install a new wing, but if they go to that much effort they might as well build a completely new airplane. It appears they are not willing to spend (gamble?) that kind of money for what they think is a limited market. On the other hand, what if they do go for an A380 competitor incorporating all they've learned on the 787 and more? That would really put the pressure on A380 sales. I wouldn't bet on it though. I think there will be substantial infrastructure issues that airlines and airports will have to make just to accommodate the large Airbus.

Now a completely new 737, there's an interesting possibility . . . .

Merril

[matt]

Yep the next ten years will be interesting times indeed, i guess at the right time Boeing will make its move, the gambles of old like the money/risk taken with the 747 aren't just done today
Thinking of risk i saw a video of when Boeing introduced the 707 and at one of the promtional displays the test pilots ..........they bloody barrel rolled it !!!!!!!!!!!! later they where called up stairs for "chat" to explain themselves......can you imagine the situation, all the top company brass in front of prospective airline chiefs etc with heaps of Boeing money tied up in this aircraft and then its barrel rolled over head! Of course from the test pilots point of view perfectly safe 1G manouver but looks very spectacular......and sold a lot of aircraft
Can you imagine if that was done today..........amazing

no sign of julian? must have got lost on a solo nav

[MerrilGordon]

If I've got my story correct, the test pilots performed that stunt at it's public debut at the local big event called Sea Fair on Lake Washington. They have hydroplane races and a bunch of other activities. I'm guessing approximately 200,000 people saw that 707 roll !
Great publicity stunt I thought
Merril