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

[fantom]

https://www.telegraph.co.uk/news/science/science-news/3290099/Aircraft-that-mimic-geese-can-save-fuel.html
Is this mad, or what ? Never mind the obvious, what about TCAS for a start?

[boaclhryul]

what about TCAS for a start?

Geese normally have TAs disabled, so not an issue.

[jimjim1]

I have seen geese myself meany times and assumed that there was an efficiency gain.

Turns out that 12% fuel saving has been achieved in tests with A380s. I assume that is for the following aircraft.

https://en.wikipedia.org/wiki/Formation_flying
"After A380s (https://en.wikipedia.org/wiki/A380) tests showing 12% savings, it launched its 'fello'fly' project in November 2019 for test flights in 2020 with two A350s (https://en.wikipedia.org/wiki/A350), before transatlantic flight (https://en.wikipedia.org/wiki/Transatlantic_flight) trials with airlines in 2021."

"Certification for shorter separation (https://en.wikipedia.org/wiki/Separation_(aeronautics)) is enabled by ADS-B (https://en.wikipedia.org/wiki/Automatic_Dependent_Surveillance_Broadcast) in oceanic airspace, and the only modification required would be flight control systems (https://en.wikipedia.org/wiki/Flight_control_system) software. ... Commercial operations could begin in 2025"

Decent looking article here - https://aviationweek.com/dubai-air-show/airbus-seeks-10-fuel-burn-savings-aircraft-flying-together

[DroneDog]

Will it be mandatory for the following pilots to "honk" to encourage the lead aircraft?

[Andrewgr2]

Thread title says aircraft flying 1.8nm apart. Seemed too far to make a difference. Telegraph article says 55 feet apart. Seems too close for comfort!

[DirtyProp]

Will it be mandatory for the following pilots to "honk" to encourage the lead aircraft?
Only when stacked. :E

Jokes aside, it seems a rather impressive saving just by flying closer and modifying the software.

Airbus estimates that the following aircraft can save 5-10% of fuel by flying 1.5-2 nm behind the preceding one. “This is not at all about formation flying,” Bour-Schaeffer stressed. “[The concept] has huge potential and is a very tangible solution. The air is quite smooth and therefore it is practical. There is no impact on passenger comfort.”
From the Aviation Week link.

[ATC Watcher]

Is this mad, or what ? Never mind the obvious, what about TCAS for a start?

Not mad, a quite old idea in fact possibly reactivated today due greater automation of flight controls .
The military used this phenomenon already in WW1.
TCAS is not an issue , RAs will only be initiated if tacks converge, not parallel. System only works with RAs coupled to FD which is already the case on the A380/350.
For ATC, also not an issue as they will it will be considered a formation flight ,which means separation is the responsibility of the crews , not ATC..
Smooth air is a prerequisite of course, and how to predict that with accuracy over the oceans is THE question for me.

[maxxer]

Our cheap flights will get cheaper they just slot in behind someone else :-)

[c52]

Gatwick doesn't need to move its spare runway 10m to the north, then.

ATC should change - speedbird 123, easyjet 456 and ryanair 789 you are all cleared to Malaga......

[lomapaseo]

Stick to the aerodynamics of planes with fixed wings in arguments. Likening any effects to geese formation flying is an aberration and a presumption.

I had always thought that geese formations were to prevent the constant leaking of spent fuel from the lead geese to get in the eyes of the trailing ones. The geese are dependent on their line of sight to avoid wing tip to wing tip affects, hence the V
.

[Private jet]

So how will they get into formation in the first place without some burning lots of fuel orbiting ?

[kcockayne]

Well, that's 60 years of Radar separation standards going out of the window. Makes you wonder why we bothered to impose 3 or 5nm. Still, it is good to know that cherished, & strictly applied, separation standards were all a complete waste of time. All those airmisses/airproxes which SRG wasted their time investigating. If only they had realised that those sort of standards could have been dismissed so easily. Glad I am out of it.

[TheFiddler]

Well, it's 17 1/2 years since that article was published and it still hasn't happened, so I shouldn't get to excited by it!

[ehwatezedoing]

Well, it's 17 1/2 years since that article was published and it still hasn't happened, so I shouldn't get to excited by it!
lol yes...

Aircraft that mimic geese can save fuelBy Roger Highfield, Science Editor

12:01AM GMT 18 Jan 2002

[KRviator]

The Yanks tested that with their C17's and found it was about 1000m away to hit the perfect spot:

According to the data generated by this month's flight and by earlier tests over Edwards, the ideal position for a drafting airplane is 3000 feet to the port side of the leading airplane. If there were a second drafting airplane, its ideal placement would be on the starboard side, about 6000 feet from the lead. This is pretty close to the tactical formations that large Air Force planes fly already, Erbschloe says, but this research will let the Air Force fine-tune the position of its planes to make sure they're riding the updrafts, not the downdrafts.
Source article (https://www.popularmechanics.com/military/a9257/vortex-surfing-formation-flying-could-save-the-air-force-millions-on-fuel-15703217/)
And another article from Aviation Week about it (https://aviationweek.com/blog/c-17s-go-surfing-save-fuel)

[compressor stall]

Scoff as you will but this has been seriously investigated by Airbus for some time to overcome the obvious issues raised above of TCAS etc. Autopilot ranging is pretty straight forward technology. If they can measure sub millimetre distances between two satellites to infer gravitational anomalies in the earth's surface, keeping two aircraft 3000m apart aint hard.

The bigger commercial issues will be getting the aircraft to depart simultaneously to formate (and not wasting time loitering for the other aircraft to join) and sorting out who gets the credits in a multi company formate. As a leader do you get X nm of leading credits that you can spend in tow with another aircraft from any company...?

Clearly the savings are greater over longer routes. Two aircraft ex LHR to MEL and SYD could stay in formation for say 18 hours then split at the last 45 mins. Similarly in reverse to European destinations. 15% fuel savings are huge, equivalent to NEO engines once more. That's a lot of pax that equals $$$$.

[segfault]

> Turns out that 12% fuel saving has been achieved in tests with A380s. I assume that is for the following aircraft.

Analysis of drafting between bicycles shows that there is also a small advantage to the leading vehicle. Its because the partial vacuum behind the leader is partly filled in by the following vehicle.

[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.

[mrdeux]

Weather avoidance would be interesting.

[meleagertoo]

Just imagine the organisation and logistical problems it would ttake to get just two long-haul airliners to do this,not to mention inter-company rivalries.
But to get a group of them?
What routes are dense enough to do this?
It'd take hours to get the formation together!
And the press hysteria about collision risk?

I checked the date, it's nowhere near April. What's going on? Something brought on by all those mushrooms this fall?

[visibility3miles]

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.

[visibility3miles]

https://en.wikipedia.org/wiki/V_formation

A V formation is the symmetric V-shaped flight formation of flights of geese (https://en.wikipedia.org/wiki/Goose), swans (https://en.wikipedia.org/wiki/Swans), ducks (https://en.wikipedia.org/wiki/Duck), and other migratory birds (https://en.wikipedia.org/wiki/Bird_migration). V formations also improve the fuel efficiency (https://en.wikipedia.org/wiki/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 (https://en.wikipedia.org/wiki/Bird_migration) routes.[1] (https://en.wikipedia.org/wiki/V_formation#cite_note-1) All the birds except the first fly in the upwash (https://en.wikipedia.org/wiki/Upwash) from one of the wingtip vortices (https://en.wikipedia.org/wiki/Wingtip_vortices) of the bird ahead. The upwash assists each bird in supporting its own weight in flight, in the same way a glider (https://en.wikipedia.org/wiki/Glider_aircraft) 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 (https://en.wikipedia.org/wiki/Induced_drag) and as a result increase their range by 71%.[2] (https://en.wikipedia.org/wiki/V_formation#cite_note-2) The birds flying at the tips and at the front are rotated in a timely cyclical fashion to spread flight fatigue (https://en.wikipedia.org/wiki/Fatigue_(medical)) equally among the flock members. Canada geese (https://en.wikipedia.org/wiki/Canada_geese), ducks and swans commonly form a skein in V formation.[3] (https://en.wikipedia.org/wiki/V_formation#cite_note-3)

Air Mobility Command (https://en.wikipedia.org/wiki/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] (https://en.wikipedia.org/wiki/V_formation#cite_note-4)
[5] (https://en.wikipedia.org/wiki/V_formation#cite_note-5)

[Rimmon]

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...

[Slippery_Pete]

The mind altering chemtrails can’t 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 haven’t been answered.

[compressor stall]

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/wikipedia/commons/thumb/7/77/Bodensee_at_Lindau_-_DSC06962.JPG/2880px-Bodensee_at_Lindau_-_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

[Rated De]

And when the gaggle arrives overhead the destination airports in Europe do they enter the hold?

Or simply land in line abreast?

[Atlas Shrugged]

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.

[compressor stall]

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?

:ugh:

[Rated De]

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-why-cant-you-be-bit-more-your-sister

[compressor stall]

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?

[Foxxster]

Don’t forget that the lead plane will have to be rotated every so often so it doesn’t get tired.

[White Knight]

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 I’ve experienced over the years🙄🙄

And of course weather avoidance has been mentioned further up the thread!!!

[ChrisVJ]

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.)

[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.

In other dated news....Icarus ignores father's advice to fly at "optimum altitude" and plummets from the sky!

[Ascend Charlie]

You'd have to be a goose to believe this.

[compressor stall]

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/press-releases/en/2019/11/airbus-inspired-by-nature-to-boost-aircraft-environmental-performance.html

Honk

[kenfoggo]

Is this a French plan? Thought so. Next!

[Momoe]

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.

[fox niner]

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.

[ConwayBorders]

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.

[340drvr]

……….. and the only modification required would be flight control systems (https://en.wikipedia.org/wiki/Flight_control_system) software. …

Yeah, because that control software scheme has worked out so well in recent months?

[SloppyJoe]

For some airlines this would not be hard to achieve on certain routes. I regularly fly from HKG to the USA, Europe and AUS. Almost every time we are in a cluster of other company aircraft. It is not unusual to have 5+ company aircraft within 100 miles of each other on the same airway. On 8-15+ hr flights it would not take up a huge amount of time to close gaps between adjacent pairs. If you have doubts look at flight radar24 at 1800z at the line of CX aircraft heading to Europe and also the USA.

[fokker1000]

Why don't we do formation take offs/landings too? double runway capacity with immediate effect! Narrow bodies only for now though I'd guess.

[RoyHudd]

Codswallop!

Moderate/severe turbulence, engine problems/shutdowns, depressurisation, sick pax/crew, formating and deformating of aircraft, all would make the idea untenable. Plus the first collision between 2 airliners would bring hundreds of dramatic deaths and an end to the silly concept.

Just a smokescreen from manufacturers to virtue-signal their green credentials.

[b1lanc]

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/press-releases/en/2019/11/airbus-inspired-by-nature-to-boost-aircraft-environmental-performance.html

Honk

How far away was that CRJ that ran into the vortice from the 380 heading the opposite direction?

[Takwis]

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/800x531/e_4b_refueling_051bbc17633b96ce3cc775edaac1e2a5f952494a.jpg

[compressor stall]

How far away was that CRJ that ran into the vortice from the 380 heading the opposite direction?

From a briefing I saw a couple of years ago the 604 was some 15nm behind and 1000' underneath on a reciprocal track, so rather irrelevant for this discussion. But to indulge your digression, it was going to be an unpleasant ride, but there's a bit more to the cause of the severity of that accident that hasn't been coherently published yet (but the data is public). One can infer what it's about from the BFU interim report and the "what not to do in wake turbulence encounters" information promulgated in more recent times.

Funnily enough the formation being proposed would actually have the surfing aircraft further away from the lead aircraft's vortices than an aircraft on a 1nm lateral SLOP recommendation to avoid descending vortices.

[421dog]

Hmm. Most of the guys I know who have formation cards have, at least once in their training 1) fully stalled an airplane to a break, 2) know how to do a chandelle and a lazy eight, 3) can land something with a tail wheel, and 4) can reliably hand fly some sort of a non-precision approach.

I really wouldn’t trust most of the regional jet jocks who learned to “fly” in a Cirrus without ever having to consider the vagaries of power, pitch, and mixture, and who did a commercial in something that was only “complex” by virtue of a glass panel to do the job...
(flame on)

[chuboy]

Hmm. Most of the guys I know who have formation cards have 1) fully stalled an airplane, 2)know how to do a chandelle and a lazy eight, and 3) can land something with a tail wheel.
I really wouldn’t trust most of the regional jet jocks who learned to “fly” in a cirrus and did a commercial in something that was “complex” by virtue of a glass panel to do the job...
(flame on)
Autopilot would be doing the flying anyway.

I think this is far easier to implement than replacing Jet A1 with biofuel.

Of course there's plenty of people saying it's all too hard, but the fact is 99%+ of cruise flight is a non-event and could easily manage this. Hit bad turbulence or there's an operational issue? Ok fine break out of formation, it's not the end of the world you'll just burn use fuel you would have burned anyway.

If these cost savings are as high as implied then there is a huge low-hanging fruit for airlines to work together here.

[421dog]

Autopilot would be doing the flying anyway.

I think this is far easier to implement than replacing Jet A1 with biofuel.

Of course there's plenty of people saying it's all too hard, but the fact is 99%+ of cruise flight is a non-event and could easily manage this. Hit bad turbulence or there's an operational issue? Ok fine break out of formation, it's not the end of the world you'll just burn use fuel you would have burned anyway.

If these cost savings are as high as implied then there is a huge low-hanging fruit for airlines to work together here.


Yup, and my point is, that, when I am flying, maybe closer to another airplane than IFR seperation might dictate, but still with visual separation, I am fairly comfortable with not flying into a guy buzzing along beside me.

i am worried that those who are not accustomed to the direct control of their craft might represent a hazard.

[tdracer]

Go back and read the original article - 12% saving at 55 ft. Let me repeat that - 55 FEET! It wouldn't take much of a system malfunction to result in a mid-air at 55 ft. - especially given it would be on auto-pilot so the crew reaction time to a malfunction wouldn't be good.
Airbus has said 1.8 nautical miles - which is doable, but the potential benefit would be a tiny - less than 1% - and things like turbulence and cross winds mean that the 'sweet spot' would be constantly moving around so staying in the right spot for hours on end would be non-trivial.
There may be some potential benefit for military - where close formation flying is the norm.
For passenger service, it's a pipe dream...

[Atlas Shrugged]

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

No. Of course not.

I understand the point you are making, but there is no such thing as something that cannot fail.

The reality is that when the automatics fail, which they can do quite readily, some aircraft can be quite a bit more difficult to operate and more importantly, because the automatics are almost always engaged, some drivers won't have recent practice to fall back on.

And that's the problem. Every day there would be thousands of events around the world where the automatics drop their bundles, and it's simply fixed by the pilots. If you stopped those fixes, it would start raining aluminium.

[fltlt]

blob:https://www.pprune.org/5b2d80f1-2225-4890-b213-6103dca187f2

Goosed or Ducked, take your pick.

[gums]

Salute!

Tnks for the reminder , TDracer. Ya gotta be close to have help. but you can be a half mile behind a heavy and see some serious roll and such.

We "lights" saw the effects of the wing downwash/upwash/vortex on a daily basis in close formation. Figure ten to fifteen feet or so.

As an experiment on a cross ocean mission I tried to use the vortex of the KC-135 tanker while maintaining nose-tail seperation ( B-70 crash fully on my mind). Sure enough, as I closed from the stern I had to hold left stick , although I was on the starboard side. So I was riding the "wave" like a surfer. Pulled back power a bit and stayed right with the tanker. My fuel flow went down a few hundred pounds per hour. So those geese have figured it out prolly a few hundred thousand years ago, ya think?

Gums recalls....

[Small cog]

Lead aircraft will have a higher fuel burn than following aircraft, thus will want to climb to a higher optimum altitude early than the following one. What then?

[Flying Hi]

Will it be mandatory for the following pilots to "honk" to encourage the lead aircraft?
I assume that the externally fitted Horn thus fitted will be fully FAA approved.

[gums]

Salute!

@ cog....

Lead aircraft will have a higher fuel burn than following aircraft, thus will want to climb to a higher optimum altitude early than the following one. What then?

Well, you follow the procedure that the geese do. Just watch a migration formation and see the lead goose change positions and a new one takes over for awhile, then another and so forth. Dem geese ain't dumb!

My tanker buddies tell me that refueling Air Force one and other big planes "pushes" them due to the "bow wave".

In the final analysis, it is actually possible to get "help" from a buddy to reduce fuel flow or even stay up due to an engine loss. But you need to be fairly close and have done it before when not under duress. Of course, then there's "Pardo's Push" as a last resort.

Gums sends...

[Takwis]

Salute!

@ cog....



Well, you follow the procedure that the geese do. Just watch a migration formation and see the lead goose change positions and a new one takes over for awhile, then another and so forth. Dem geese ain't dumb!

My tanker buddies tell me that refueling Air Force one and other big planes "pushes" them due to the "bow wave".

In the final analysis, it is actually possible to get "help" from a buddy to reduce fuel flow or even stay up due to an engine loss. But you need to be fairly close and have done it before when not under duress. Of course, then there's "Pardo's Push" as a last resort.

Gums sends...

We got a little nudge from the B-52s...enough to be noticeable. Basically nothing, from another -135. Nose is too pointy. But a C-141 had a significant bow wave, with that broad nose, and the C-5 was like wintertime at Steamer Lane; a great big wave. My 19-year-old Boom Operator gave me very accurate range calls as a C-5 moved in, and I would give little anticipatory bursts of trim, based on his calls. The old autopilot would often kick off, with C-5s, so I just did it all manually.

Another neat thing that the Old Boeing did was design the -135 and the B-52 to work together aerodynamically. The B-52 wingtips were outside of our downwash and vortices. If the Buff moved right, he had more wing outside the downwash on the right side, and the plane naturally wanted to ease back to the left. I wouldn't be surprised if the combo of the two airplanes wasn't a little more fuel efficient...with 12 motors running, I don't think we would have noticed much. But if 55 feet is an optimum distance, we were right in that range (not counting the boom, which of course was touching the other airplane).

Squawk was a pretty simple matter. Lead tanker squawked, anyone on the boom or the wing went STBY, and the farthest trailer behind also squawked. At times we had five tankers in trail, each with a flock of receivers. The formation would be more than 5 miles long. Lots of metal between those two transponder returns.