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Aircraft to fly in formation 1.8 nm apart to save fuel like geese do

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Aircraft to fly in formation 1.8 nm apart to save fuel like geese do

Old 20th Nov 2019, 00:01
  #21 (permalink)  
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Okay, what do you mean by fly "1.8 nm apart"???

The article says:

n tests, two planes used the Formation Flight Information System to fly 55ft apart over the same distance. Initial results suggest the trailing plane used 12 per cent less fuel than the lead plane.
I suspect they'd have to fly very close together for maximum fuel savings.

Look at how closely race cars and cyclist follow each others tails to benefit from drafting.

Geese coordinate the way that they flap their wings to maximize the benefits of each others slipstreams. I doubt that planes or helicopters could gain advantage from such subtleties unless they pay close attention to wingtip vortices.

Don't forget the V formation in flight. It helps geese even if they only have one goose to one side of the lead goose, with the rest of the flock angling off to the other side.
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Old 20th Nov 2019, 00:16
  #22 (permalink)  
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https://en.wikipedia.org/wiki/V_formation

A V formation is the symmetric V-shaped flight formation of flights of geese, swans, ducks, and other migratory birds. V formations also improve the fuel efficiency of aircraft and are used on military flight missions.
The V formation possibly improves the efficiency of flying birds, particularly over long migratory routes.[1] All the birds except the first fly in the upwash from one of the wingtip vortices of the bird ahead. The upwash assists each bird in supporting its own weight in flight, in the same way a glider can climb or maintain height indefinitely in rising air. According to a 1970 paper, in a V formation of 25 members, each bird can achieve a reduction of induced drag and as a result increase their range by 71%.[2] The birds flying at the tips and at the front are rotated in a timely cyclical fashion to spread flight fatigue equally among the flock members. Canada geese, ducks and swans commonly form a skein in V formation.[3]
Air Mobility Command, which accounts for 20 percent of all avionic fuel usage by the United States federal government, is experimenting with autopilot changes to find the best tradeoff between the reduced drag of 'vortex surfing' and the resulting 'ride qualities' of flying through another aircraft's wake.[4]
[5]
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Old 20th Nov 2019, 00:42
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Originally Posted by Ascend Charlie
And on arrival, number 2 plane then has to use up fuel orbiting while waiting for the lead goose's wake turbulence to go away, and leave space on the runway/taxiway to move around.
Or the trailing plane reduces speed a bit earlier than the leading plane, creating a suitable separation without any orbiting or fuel waste...
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Old 20th Nov 2019, 00:48
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The mind altering chemtrails canít be dispersed evenly if we all follow each other along the exact same route.

How does the lead aircraft spray without getting the aircraft behind?

Lots of big questions that havenít been answered.
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Old 20th Nov 2019, 01:21
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Look at how closely race cars and cyclist follow each others tails to benefit from drafting.

Geese coordinate the way that they flap their wings to maximize the benefits of each others slipstreams.
Important point is that the second aircraft is not "drafting" You're not getting a tow.

The second aircraft is surfing the wave out to the side of the first. It's similar to the Kelvin wake. visible here https://upload.wikimedia.org/wikiped...-_DSC06962.JPG

And if you're surfing the wave, you're getting free uplift, so power reduces.

At least that's my recollection of discussion with some researchers in the early days of this project
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Old 20th Nov 2019, 01:56
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And when the gaggle arrives overhead the destination airports in Europe do they enter the hold?

Or simply land in line abreast?
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Old 20th Nov 2019, 02:26
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Formation flying, by people who don't do it regularly, is a good starting point for the various "Air Disaster" shows..... or possibly a Youtube opportunity in the making.
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Old 20th Nov 2019, 02:38
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Angry

Originally Posted by Rated De
And when the gaggle arrives overhead the destination airports in Europe do they enter the hold?

Or simply land in line abreast?
No - they land at their respective airports. From TOD, one peels off to Gatwick, one to London etc having formate for the last few hours saving $$ and fuel.

And Altas - as for formation flying skills - are you allowed to fly above FL290 without and autopilot?

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Old 20th Nov 2019, 03:03
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What am amazing concept as long as one lives in suspended reality.
Am amazing theatrical performance as aircraft form different FIR somehow formate.
Kabuki theatre.

Geese fleets, bio-fuel and electric aircraft all provide distraction from the actuality: Technically feasible but practically fanciful.
In the meantime the industry has no plan for transition from hydrocarbon based fuel, no ETS for seven years (and then only international), a low price on carbon and ASK growth rates that will ensure by mid century CO2 emissions from the industry are among the highest on the planet. Consumption of hydrocarbon based fuel continues unabated.

Fortunately, the world can breathe easy, industry lapdog ICAO will be bound to build bigger offices in Montreal and invite dialogue from member states at numerous "conferences" where jet fuel brings delegates to the talk fest.

Nothing to see move along.

https://theicct.org/blog/staff/icao-...re-your-sister

Last edited by Rated De; 20th Nov 2019 at 06:00. Reason: punctuation
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Old 20th Nov 2019, 03:20
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Perfectly suited for say 2xA350s from LHR to SYD and MEL. They depart a minute apart then fly in company for 18 hours, then part ways near TOD. There are not going to be thousands of aircraft from different FIRs suddenly formating to go places. But of course you know that.

Yes, the transition from hydrocarbon is the number one priority, but taking a small step to save ca 10% on fuel on some routes is not a backwards step in the short term. Ignoring environmental benefits, the cost savings alone will be great. The tech is here, the biggest stumbling blocks will be airport slots.

And if they get the slot logistics sorted, and it works out to even a 5% saving on propulsion, that will benefit post hydrocarbon propulsion (whatever form that takes) won't it?
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Old 20th Nov 2019, 04:03
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Don’t forget that the lead plane will have to be rotated every so often so it doesn’t get tired.
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Old 20th Nov 2019, 05:54
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And then of course the lead aircraft has to go back to the gate to offload a sick pax. Or one of many other delaying scenarios Iíve experienced over the years🙄🙄

And of course weather avoidance has been mentioned further up the thread!!!
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Old 20th Nov 2019, 06:04
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When I was a kid slip streaming on the race track was a big thing but the following car had to be within feet of the leader. The tchnique was to use slip streaming for the first part of the straight to gain a few extra MPH and then pull out and use those MPH to get past. I was astonished recently to learn that Formula 1 cars are now affected by the wake turbulence of a car ahead of the by up to three or four seconds. (They use a lot of aerodynamic down force and in turn create substantial turbulence.)
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Old 20th Nov 2019, 06:07
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Did this thread start on April 1st?

Can't be many pilots on this thread - no one is discussing wake separation issues - there are historic and scientifically proven facts that point to the inherent dangers of flying in the wingtip vortices of other aircraft. No, this is a non starter for so many reasons.

In other dated news....Icarus ignores father's advice to fly at "optimum altitude" and plummets from the sky!
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Old 20th Nov 2019, 07:08
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You'd have to be a goose to believe this.
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Old 20th Nov 2019, 07:33
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Originally Posted by petrichor
Did this thread start on April 1st?

Can't be many pilots on this thread - no one is discussing wake separation issues - there are historic and scientifically proven facts that point to the inherent dangers of flying in the wingtip vortices of other aircraft. No, this is a non starter for so many reasons.
If you're a pilot you'd know that wake vortices tend to stay directly behind the wing tips, they don't expand outwards (much).

The plan here is not to fly in the vortex or the wake, much the same way geese don't.

Here's the source info from the public project release at Dubai this week.

https://www.airbus.com/newsroom/pres...rformance.html

Honk
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Old 20th Nov 2019, 07:43
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Is this a French plan? Thought so. Next!
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Old 20th Nov 2019, 08:08
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If 1000m is the sweet spot, that's not an issue. It will require TCAS reprogramming to acknowledge the 'Buddy' but read the information people,

This isn't slipstreaming, this is wave surfing and vertical separation is already way less than 1000m in the stack. Two planes 1k apart at the same speed would have plenty of time to take avoiding action, first sign of turbulence lead goes one way, vertically and horizontally and 'surfer' goes the other - simples.

Potential savings are huge, especially as we're trending towards longer, point-to-point scheduling.

Acknowledge the argument that airlines are a (large) net CO2 producer, but at the present time, no other commercially viable solution exists, therefore any scheme to reduce CO2 should be received a little more positively.
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Old 20th Nov 2019, 08:31
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Originally Posted by kenfoggo
Is this a French plan? Thought so. Next!
It sounds like a completely stupid plan to me. Consider this:
Suppose we can find two flights that can be teamed up. They both have to take off from some airfield. What if one of them is delayed by a minute or so? This will create Slot times as accurate as 0855.20 Z. And dedicated taxi routes completely free toward the holding point. Assuming that all goes well with both aircraft when they start up.
What if one of them needs to check te MEL after startup?
What if one needs to sort things out with passengers?
What if one needs to level off because of traffic once airborne?
Etc.
Too many variables. And the trailing aircraft suddenly does not have a leading buddy. But had expected a leader, and has 10%less fuel on board. Now it wont make it to destination.
Too many variables.
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Old 20th Nov 2019, 09:57
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I actually think you're overestimating the complexity. See it as a future project in a time where (hopefully) SESAR2020 reforms to EU airspace has taken place: If you can get a direct routing from a London Control exit point, through Maastricht, Rhein, Prague, Bratislava, Hungary, Romania, etc. on your way from LHR to MEL, another aircraft going to DXB, DOH, SYD, MEL, etc will likely get a similar direct routing. If he is 7nm to your right and in front, you might able to get vectors to "link up" with him. If Airbus implements an autopilot function to keep you 1000m behind him and to the side, the lead aircraft can be given WX and Traffic avoidance instructions by ATC as if you were a formation flight. In that case, it might even simplify ATC operations because two aircraft can be treated as one flight.

All it requires is a vaguely similar starting point and the same exit point from the Free Route Airspace.
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