Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Boeing Dreamliner draws a gigantic outline of a Dreamliner
CBC ^ | 08/04/2017 | Daniel Schwartz

Posted on 08/04/2017 5:35:17 AM PDT by Phlap

On Wednesday afternoon, a Boeing 787-800 Dreamliner took off from Seattle on a test flight. Flight tracking apps show the Dreamliner followed a flight path over the United States that draws an outline of the Dreamliner.

It set the internet abuzz, likely one of the goals. But the Dreamliner was actually conducting a flight test of its new Rolls Royce engine "to prove to regulators that the airplane can safely operate on one engine for an extended period of time," according to Flightradar24, a flight-tracking app.

(Excerpt) Read more at cbc.ca ...


TOPICS: News/Current Events; US: Washington
KEYWORDS: aerospace; aviation; boeing; manufacturing
Navigation: use the links below to view more comments.
first previous 1-2021-34 last
To: Excellence


Pillows compensate...

bp-15


21 posted on 08/04/2017 7:31:53 AM PDT by golux
[ Post Reply | Private Reply | To 19 | View Replies]

To: Excellence

22 posted on 08/04/2017 7:34:28 AM PDT by Mr.Unique (The government, by its very nature, cannot give except what it first takes.)
[ Post Reply | Private Reply | To 19 | View Replies]

To: Excellence

No comprende.


23 posted on 08/04/2017 7:48:25 AM PDT by smokingfrog ( sleep with one eye open (<o> ---)
[ Post Reply | Private Reply | To 19 | View Replies]

To: Red Badger

The 787 has a range of over 9000 miles. I’m sure someone at Boeing Flight Test did the math before they took off.


24 posted on 08/04/2017 8:15:00 AM PDT by stormer
[ Post Reply | Private Reply | To 9 | View Replies]

To: smokingfrog
I can’t imagine that would be very fuel efficient

Yes, with one engine out, power still goes to both rotors. There is enough power to maintain level flight at about 80 knots. Of course the one engine is using a little more fuel on one engine, less what the other engine no longer is drawing, then when both engines were online.

I would bet the USMC has figured this out with the 3 engine CH-53E. Shut one down and watch the range go up. The theory is those gas turbines use about the same amount of fuel no matter if you are pulling lots of torque or not. And one less engine

Just really curious what Boeing knew about their flight.

Gee - if that last engine goes out, we might be up here all day, lol

25 posted on 08/04/2017 8:24:21 AM PDT by Dustoff45 (Pass the spicy catsup. We've got Trump now.)
[ Post Reply | Private Reply | To 16 | View Replies]

To: Excellence

“Those are some tight turns!”
Yeah, only like 10 miles turning radius.


26 posted on 08/04/2017 8:24:27 AM PDT by TalonDJ
[ Post Reply | Private Reply | To 2 | View Replies]

To: Dustoff45

“... I used to argue with my maintenance officer that I could extend the range and ferry distance of a CH-47, if we but just shut down one engine, fly at lower airspeed, yet extend our distance and of course time enroute. I was told I could not do it, as it was en emergency condition. I argued back that I must have been in an emergency every time I flew a single engine Huey.

With one engine out, only half the fuel is being consumed. Adjust for some lack of performance and the range should be increased.”

Doesn’t work that way for a multi-engined fixed wing when it’s one engine inop (with no engines on the centerline of the a/c) because the operating engine is creating a condition of asymetric thrust.

As I’m sure you know, best performance (and usually the best directional control, too) is always in a zero sideslip condition. When you’re all engines operating, wings level and a centered trim ball indicates zero sideslip. But when you’re OEI, the operating engine is constantly exerting a yawing force on the airframe which, left unchecked, will expose more of the a/c’s profile and increase overall drag. So when you’re OEI, because thrust is being applied asymetricaly, zero sideslip in created by trimming to 1/3 to 1/2 of the ball toward the operating engine and banking 2-3° toward the operating engine.

Although it’s the OEI best performance condition, it’s still compromised (compared to all engines operating) because it was achieved by using unbalanced aerodynamic forces to counteract the asymetric thrust. Either AEO or OEI, best range will be at the same Vy airspeed, but drag will always be higher OEI because you’re using opposing forces to null each other out (= loss of efficiency). So shutting one engine down is always going to result in a shortened range, even if you could maintain Vy.

What you suggest might work with a ‘Hook, provided you can maintain your max range airspeed when you’re OEI because OEI won’t result in asymetric thrust. It worked with Rutan’s Voyager (flew around the world on one tank of fuel) because both of its engines are on the centerline (like the Cessna O-2 “Pushme-Pullyou”) and the OEI didn’t result in any asymetric thrust. In fact, they did shut one down when in cruise to extend their range.

If you want to see how one of the best aero engineers yet to draw breath sought to deal with OEI asymetric thrust in a FW light twin (and gain some appreciation for what a compromised condition it is, not to mention how far “outside the box” he thinks), check out Burt Rutan’s “Boomerang”: http://bit.ly/2weUijc

As for the Chinook, I never got a warm fuzzy from flying in any a/c that can have a mid-air collision with itself. :-P


27 posted on 08/04/2017 11:18:36 AM PDT by Paal Gulli
[ Post Reply | Private Reply | To 11 | View Replies]

To: Vlad The Inhaler

Hey Gore, tell us all about Occidental and your family.


28 posted on 08/04/2017 11:25:47 AM PDT by Mastador1 (I'll take a bad dog over a good politician any day!)
[ Post Reply | Private Reply | To 3 | View Replies]

To: Dustoff45
OEI illustrated

The first image shows what naturally happens when one engine craps the bed (unless countermanded from the cockpit).

The second shows why centering the trim ball only compounds your problems when you're OEI.

Profile drag is berry berry bad in either 1 or 2 because the fuselage is flying sideways (relative to direction of flight).

The third shows how "raising the dead" (engine) and out of trim (ball) produces a zero sideslip condition OEI. Dunno why the wings look wonky, might be a 2D effort to show that it's banking toward the operating engine.

Image and video hosting by TinyPic
Bottom line, in a "conventional" FW twin, powered flight when OEI will always result in asymmetric thrust, which can't help but carry a drag penalty, regardless how you deal with it.
29 posted on 08/04/2017 11:59:44 AM PDT by Paal Gulli
[ Post Reply | Private Reply | To 11 | View Replies]

To: Paal Gulli
As for the Chinook, I never got a warm fuzzy from flying in any a/c that can have a mid-air collision with itself

So True - Great discussion that speaks directly to the challenge Boeing must have faced with the flight.

30 posted on 08/04/2017 12:27:11 PM PDT by Dustoff45 (Pass the spicy catsup. We've got Trump now.)
[ Post Reply | Private Reply | To 27 | View Replies]

To: Paal Gulli
Nothing is quite like parachuting from the ramp of a Chinook, though. Really cool.


31 posted on 08/04/2017 3:40:15 PM PDT by smokingfrog ( sleep with one eye open (<o> ---)
[ Post Reply | Private Reply | To 27 | View Replies]

To: Phlap

GPS controlled and guided tractors make corn mazes

Boeing made a corn maze on a very large scale


32 posted on 08/04/2017 3:46:16 PM PDT by Thibodeaux (Democrat calls for kumbaya must be met with their blood on the ground)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Mastador1
Hey Gore, tell us all about Occidental and your family.

And the zinc mine on his farm in Carthage, Tennessee.

A mine that was known to be polluting the water and soil.

Hometown Paper Exposes Zinc Mine on Al Gore's Property

http://www.foxnews.com/story/2007/03/20/hometown-paper-exposes-zinc-mine-on-al-gore-property.html

Al Gore - Environmentalist And Zinc Miner


33 posted on 08/04/2017 3:57:18 PM PDT by Vlad The Inhaler (We were Trumpin' before Trumpin' was cool.....)
[ Post Reply | Private Reply | To 28 | View Replies]

To: Red Badger
More information about "boeing-uses-a-787-to-draw-a-787-dreamliner-during-etops-test" can be found here
34 posted on 08/04/2017 11:05:04 PM PDT by sjm_888
[ Post Reply | Private Reply | To 9 | View Replies]


Navigation: use the links below to view more comments.
first previous 1-2021-34 last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson