60 years ago: The famous Boeing 707 prototype barrel roll over Lake Washington

http://www.seattletimes.com/seattle-news/60-years-ago-the-famous-boeing-707-barrel-roll-over-lake-washington/

by Turing_Machine • 11 years ago

201 61 11 years ago

userbinator2• 11 years ago

Interestingly enough, if the occupants weren't looking outside, a "1G roll" would feel almost the same as level flight; here's a video showing how "gravity" seems to invert along with the plane:

https://www.youtube.com/watch?v=pMWxuKcD6vE

This is also why pilots can become spatially disoriented:

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

WillPostForFood• 11 years ago

The article quotes the pilot, Tex Johnston, saying something similar,

"The airplane does not recognize attitude, providing a maneuver is conducted at one G. It knows only positive and negative imposed loads and variations in thrust and drag. The barrel roll is a one G maneuver and quite impressive, but the airplane never knows it’s inverted.”

mnw21cam3• 11 years ago

Problem is, it isn't actually a 1G manoeuvre. You can only have a constant 1G if you are in straight and level flight. If you perform a gentle turn, you will have very slightly more than 1G as you bank around the turn.

With roll, if you pull positive 1G while inverted, the plane will effectively be accelerating towards the ground twice as much as if it was in free fall. When the roll is over, in order to regain straight and level flight, more than 1G must be pulled to counteract the groundwards velocity that has been accumulated.

jessriedel• 11 years ago

Of course. Level flight isn't exactly 1G either because of small amounts of turbulence. The point is that the load is arbitrarily close to 1G, given a slow enough roll (and enough altitude).

alblue• 11 years ago

A descending turn can be done with <1G - it's only a level turn will pull more than 1G.

skrebbel• 11 years ago

Ok that's impressive. I'd definitely pay extra for my Ryanair holiday flight to do that once or twice!

js2• 11 years ago

Somewhat related, great piece of writing about the banked turn - http://www.theatlantic.com/past/docs/unbound/langew/turn.htm

neurotech12• 11 years ago

Even seen Bob Hoover do a "1G roll"?

https://www.youtube.com/watch?feature=player_detailpage&v=9Z...

cfj• 11 years ago

Technically called an aileron roll.

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

__rzzzwilson__• 11 years ago

No, a barrel roll is different to an aileron roll. The wikipedia article linked to shows the difference.

A barrel roll requires heading and altitude changes, an aileron roll should not.

agumonkey• 11 years ago

Yeah it's was confusing, an aileron roll wouldn't allow for this https://www.youtube.com/watch?v=pMWxuKcD6vE (posted above). Unless you rotate faster than gravity pulling the water down.

cpncrunch6• 11 years ago

Yes, the are different. However what the OP is pointing out is that Tex actually did an aileron roll and not a barrel roll. (Watch the video and it's pretty obvious).

dingaling2• 11 years ago

Correct, a barrel roll requires 90 degree changes-of-course through the manouevre.

Think of the seam-line on a toilet-roll tube; that's the path a barrel roll requires. Lots of pitch and roll, it is not a simple manoeuvre and has to be taught:

https://www.youtube.com/watch?v=hASm6-2QLDU

To my knowledge no airliner has ever been barrel-rolled, it is a high-stress manoeuvre.

Tex himself never claimed it was a barrel roll.

userbinator2• 11 years ago

To my knowledge no airliner has ever been barrel-rolled, it is a high-stress manoeuvre.

Tex himself never claimed it was a barrel roll.

I think you've confused them; Tex says, quoted in the article, "The barrel roll is a one G maneuver and quite impressive, but the airplane never knows it’s inverted", while the aileron roll causes negative G at the "top" when the plane is inverted.

InclinedPlane• 11 years ago

No. The 707 did an actual Barrel Roll, not an Aileron Roll.

cpncrunch6• 11 years ago

No, definitely not a barrel roll. Watch the video and it's clearly obvious that it's not a barrel roll. Also, a barrel roll isn't a 1g maneouver.

mckoss• 11 years ago

An aileron roll will experience -1G - something you really don't want to do in an airliner. A barrel roll is specifically named because its like driving around the inside of a barrel; the plane always maintains positive Gs.

jlangenauer• 11 years ago

It's also claimed, though there's no footage in existence, that a barrel roll has been performed in a Concorde.

https://www.youtube.com/watch?v=KYQS3qAIjAo

PhantomGremlin• 11 years ago

It has to be true. I saw it in a cheezy B movie, surely it wasn't special effects?

Or maybe it was just a roll, not a barrel roll. I can't remember, it's been 35+ years and I don't want to see the movie again. Anyway, we were expected to believe that the Concorde is maneuverable enough to evade both a SAM and missiles from a fighter. My "suspension of disbelief" unfortunately didn't kick in. https://en.wikipedia.org/wiki/The_Concorde_..._Airport_%2779

Hmmm ... reading the Wiki entry makes me think about wanting to see that movie again. So many bad disaster films were made in the '70s.

Gravityloss• 11 years ago

If you watch the video Sosuke posted, the Concorde seems surprisingly maneuverable. Probably since it has a short span so it can roll quickly and a large amount of thrust.

Actually, the movie used models, you can see the loop scene here: https://www.youtube.com/watch?v=Ny_JslCCPxk&feature=youtu.be...

WalterBright2• 11 years ago

That picture is one of the two most famous aviation pictures. The other one, of course, is the 1903 first flight.

binarymax• 11 years ago

When you hire a pilot with the nickname 'Tex', expect showmanship.

tempodox• 11 years ago

Is it unreasonable to expect the ability to barrel-roll from any motorised plane (i.e. not a glider)?

hn_user2• 11 years ago

Any airplane should have no problem--but legally, not allowed unless it is certified for it.

bmir-alum-0073• 11 years ago

Any U.S. pilot caught pulling such maneuvers would be pwned by the FAA. Any Boeing-employed pilot would be summarily fired as well.

mikeash3• 11 years ago

No need for a motor, you can do it in a glider too.

georgerobinson• 11 years ago

Is there anything about the Boeing 707 structurally that makes it possible to do a barrel roll that would not be possible in later generation jets, such as the 757, 767, 777 and 787?

mnw21cam3• 11 years ago

No. A barrel roll doesn't place much in the way of demands on an airplane's structure.

WalterBright2• 11 years ago

Non-aerobatic airframes are not designed to pull high negative G's. The other problem with negative G's is the junk that accumulates in the bottom of the airplane can fall upwards and cause problems.

This is why Tex was careful not to pull negative G's.

Steko• 11 years ago

What were you doing Tex?

I was selling airplanes.

https://www.youtube.com/watch?v=Ra_khhzuFlE

Here's Boeing, doing a 'near vertical' takeoff in the Dreamliner (spoilers: not really but still impressive), also presumably selling airplanes.

https://www.youtube.com/watch?v=KYbM-3E11Qo

goatforce5• 11 years ago

I was at the Farnborough airshow in 1998. Farnborough is one of the largest commercial/trade airshows in the world. Wikipedia says that $72bn worth of aircraft were bought at the last show.

The commercial jets are really thrown around at the show. Steep take offs and really tight banked turns low to the ground so that the aircraft can remain visible to the people at the airshow.

https://www.youtube.com/watch?v=T3EgoPDBvLc

The planes are more than capable of these manoeuvres, but paying passengers don't want to imagine themselves riding in those planes. Passengers want slow, steady and graceful flights that wont spill their drinks or upset their stomachs.

JacobAldridge• 11 years ago

I use this example whenever I'm presenting on the difference between 'Radical' (High Risk, High Return) and 'Strategic' (Low Risk, High Return) plans. The difference between the two is Capability - ie, having strategic capability lowers risk.

This barrel roll, while not a strenuous manoeuvre on the 707, nevertheless demonstrates confidence in Boeing's manufacturing capability and by executing it Tex Johnstone convinced plane buyers that purchasing a jet was not a high risk strategy. "Selling planes" indeed!

cpncrunch6• 11 years ago

It's not really a "low risk" maneuver to do an aerobatic maneuver on an aircraft that isn't certified for it and that doesn't have a g-meter. Ask the crew of the Lufthansa B720 that crashed trying to do a roll in 1964.

http://aviation-safety.net/database/record.php?id=19640715-0

inthewoods• 11 years ago

Does the size of the plane make executing a roll of this nature challenging?

strasser• 11 years ago

I wouldn't believe so - as Tex explained:

“The airplane does not recognize attitude, providing a maneuver is conducted at one G. It knows only positive and negative imposed loads and variations in thrust and drag. The barrel roll is a one G maneuver and quite impressive, but the airplane never knows it’s inverted.”

As long as you have enough thrust and the plane can withstand the G force, it will roll.

codeonfire• 11 years ago

Yes, I as a layperson can see all sorts of differences that impose large problems. More mass = larger moment of inertia, slower roll, larger "barrel", and more energy needed. The roll could take 3x longer in a large plane, but other things like max speed and power to weight are not 3x better.

mannykannot2• 11 years ago

Perhaps inspired by Falk's performance in an Avro Vulcan prototype at the '55 Farnborough, which I think was in July.

https://www.youtube.com/watch?v=afj19PedlxE

stefap2• 11 years ago

I have a feeling that in today's corporate culture he would be probably fired.

Zikes• 11 years ago

According to the article, he was very nearly fired in 1950s corporate culture.

Regardless of intent or results, pulling an unsanctioned literal stunt with hardware that represents the majority of your company's assets is going to be frowned upon.

lotharbot• 11 years ago

some sources say he was fired and then un-fired later in the day, when new aircraft orders started pouring in.

termain2• 11 years ago

That aircraft is more properly called the 367-80, or "Dash 80". While it did serve as the prototype of the 707, its fuselage isn't as wide.

The KC-135 tanker and its derivatives also derive directly from the Dash 80, rather than the 707. It retains the 80's more narrow fuselage.

stephengillie• 11 years ago

And the article says thus: It had become Johnston’s job to travel all over the U.S. to show off the Dash 80, as the 707 was code-named.

termain2• 11 years ago

It does, it's just kind of wrong. Things are more interesting than that.

Dash 80 was a nickname for that particular plane, it's model number is 367-80. The 707 is a slightly different aircraft that generally isn't referred to as a "Dash 80".

The Dash 80 was the prototype for the 707, but strictly speaking, it's model number isn't 707.

sosuke• 11 years ago

I'm stunned that Bill Allen left behind the photo he was presented with at the banquet. While he may have not liked it at the time it seems like he never forgave or recovered from it.

wkcamp• 11 years ago

How quickly would the 707 drop in altitude while doing a barrel roll? And did he need a minimum speed to be able to successfully do it (sort of like an escape velocity)?

cmsmith• 11 years ago

If it is truly a 1G maneuver, then the answer would be:

    9.8 m/s^2  *  (1-cos(\theta))

Where \theta is the angle off of level flight. So when you are fully inverted, the plane would be accelerating at 2 G's downward (one to feel like you were in free-fall inside the cabin, and then one more to push you back into your seat).

In the film, the roll takes about 12 seconds. A quick numerical integration shows that by the end of the turn you would be 700m lower than you started, and have a downward velocity of 120m/s. I'm not a pilot, but I'm sure that the best practice here would be to start with an upward velocity, and not to really keep 1G throughout the turn. Those could both lessen your loss of altitude.

60 years ago: The famous Boeing 707 prototype barrel roll over Lake Washington

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