9 ms·

Wait until you hear about how Cameron filmed the scene with a helicopter going under a highway overpass. https://filmschoolrejects.com/terminator-2-helicopter-

by themgt 5y ago

Wait until you hear about how Cameron filmed the scene with a helicopter going under a highway overpass. https://filmschoolrejects.com/terminator-2-helicopter-stunt/ https://filmschoolrejects.com/terminator-2-helicopter-stunt/

deleted 5y ago
[deleted]
jandrese 5y ago
That is an incredible feat of flying. I would be terrified of some kind of reverse ground effect from the road overhead. It's basically a 1990s version of barnstorming.
- lisper 5y ago
  From TFA: "I was curious about how the overpass would affect the ground effect of the helicopter. Tragically, I have no brain for physics. But I do know a helicopter pilot, so I asked him. Apparently, at 60 kts, there wouldn’t be significant ground effect because the down flowing air off of the rotor disk would mostly be tailing off of the helicopter. Had Tamburro taken the stunt slower, the down flowing air would be more directly underneath the helicopter, creating an (obviously undesirable) effect."
  - jandrese 5y ago
    That part was talking about the traditional ground effect. There isn't much study about what happens when you have a ceiling over a helicopter because that doesn't happen very often in real life. Note the discussion of the air flowing off of the blades. I was thinking more of the low pressure zone above the helicopter being disrupted by the overpass. Apparently it wasn't too bad since the pilot managed the stunt twice without injury, but it's a possibility that would have had me crapping diamonds if I were asked to pull it off.
    - lisper 5y ago
      I feel an aircraft-on-a-conveyor-belt moment coming on. So first of all, GE in a rotorcraft is different from GE on a fixed-wing aircraft. The fundamentals are the same, of course, but in a rotorcraft the relative velocity of the blade/wing isn't connected to the velocity of the airframe the way it is in a fixed-wing aircraft. In a fixed-wing aircraft the velocity of the wing and the velocity of the airframe are the same, of course. But in a rotorcraft things get very complicated. The upshot of all this complication is that the GE effect is reduced as the rotorcraft's airframe starts to move. The faster it goes, the less GE you have. So you might notice some differences while hovering under an overpass, but shooting through at 60 MPH the GE is effectively a no-op. If you really want to know the gory details you'll have to read up on helicopter theory. It's way too complicated for an HN comment.
      - ambicapter 5y ago
        He's not talking about ground effect, he's talking about the overpass above the blades "cutting off" available air for a second.
        lisper 5y ago
        Yes, I get that. "Reverse ground effect" was how the OP phrased it. What exactly do you think would happen in that case? Suppose the available air were "cut off" by the overpass (it wouldn't be, but let's suspend disbelief for a moment). What would be the result?
        jandrese 5y ago
        Loss of lift due to the interruption of the airflow causing the helicopter to crash into the ground at speed? Or suddenly lower pressure above the helicopter causing it to be "sucked up" into the ceiling. I think the pilot is probably correct that the stunt could only be pulled off at a higher speed where you can outrace the low/high pressure zones the blades are creating.
coldcode 5y ago
If people survive such a crazy stunt, you congratulate them, if not, you bury them and the director. Risking people's lives for a few seconds of film is not worth it.
- capableweb 5y ago
  I'm fairly sure the people doing these stunts do them because they love doing them, not because they are being forced to perform them. If people want to risk their lives for a few seconds of film, why stop them? People are into all kind of weird stuff, as long as they don't hurt others, I don't see what the problem is.
  - ashtonkem 5y ago
    Reality is far more complex than that. Yes, stunt people tend to be a risk seeking crowd. But there’s also the risk of losing their livelihood if they refuse a director’s demands. Film business is a precarious way to make a living, and the power gulf between the director and the stunt person is massive. History is full of “I think this is a bad idea, but I’ll do it” accounts in the after-disaster reports. People can and regularly do dangerous things against their better judgement because they were ordered to do it or otherwise pressured into it. Saying that they volunteered is to drastically over simplify the situation.
    - capableweb 5y ago
      So again, they chose between doing stunts or doing something else. You don't work to do the stunts in the movie? Fine, don't work on the movie, it's not essential to life anyways so continue on with your life.
      - ashtonkem 5y ago
        Continue with your life, and risk losing your career. I think if you’re not accounting for this risk in how people think, then you are absolutely misunderstanding what motivates people to do what they do. Again, people regularly do things against their best judgement because of social and economic pressure. Stunt people are not magically excluded from this process.
russdill 5y ago
Seems like if you just wanted the side shot and not the straight on shot as well, you could of just pulled the helicopter on a low trailer using the median partition to block. The straight on shot would of required deleting the trailer which may have been difficult but certainly would look better than any CGI attempt
- capableweb 5y ago
  Or just CGI. But as Cameron himself puts it (copied from the article linked in parent): > we could’ve run a CG helicopter under the freeway overpass, but it was so much more fun to do the real thing. I'm guessing the same applies from pulling a helicopter on a trailer. It's simply not fun.
ghoward 5y ago
As an aspiring helicopter pilot, I am both awed and repulsed. Vietnam was something else for helicopter pilots. That level of skill would be hard for a perfectly-programmed autopilot to do. With regards to Vietnam, a legend that I was told (but cannot confirm) was that Hueys had such bad tail rotor authority that they would take off straight up with the whole airframe spinning. Once high enough, the pilot would start the helicopter moving forward, which would allow the tail rotor to bite more, and the helicopter would stabilize. Crazy if true. And after seeing a stunt like that by a bona fide insane and top-tier veteran pilot, I believe the legend.
- naikrovek 5y ago
  literally any Vietnam documentary would prove that wrong. what does "moving forward" even mean when you're spinning? also, forward movement doesn't give the tail rotor any more "bite" ... if anything, it would get less. moving in a consistent direction would tend to orient the body of the helicopter to face into the wind because of the wind vane effect.
  - nwallin 5y ago
    While hovering, the tail rotor is pushing air into a dirty vortex. A small amount of speed, even just 20kt, will clear that vortex and give more authority. Even today helicopters will begin pitching nose down immediately on takeoff to get airflow cross both the main and tail rotor to clear those vertices. That being said, I've talked to a few Vietnam helicopter pilots and all of their stories were ... well, exaggeration is a common theme.
    - naikrovek 5y ago
      pitching the nose down certainly does one thing: it pushes air backwards, meaning the helicopter starts moving forwards. the air moving across the body of the helicopter, rather than down it, is what starts the wind vane effect. if the pilot tipped the helicopter to the right after leaving the ground, and then continuously held the control stick in the direction of the movement of the helicopter, the body of the helicopter would begin to face the direction of travel unless the pilot actively countered that turn via the tail rotor.
marcodiego 5y ago
Something a bit crazier was performed in Brazil in the 60's for a film: https://youtu.be/rSH3FVzcDSo?t=519 https://youtu.be/rSH3FVzcDSo?t=519
chrisgd 5y ago
Not too long after two children and an adult actor were killed on the set of the twilight zone movie. https://en.m.wikipedia.org/wiki/Twilight_Zone_accident https://en.m.wikipedia.org/wiki/Twilight_Zone_accident
felipelemos 5y ago
This reminds me the 1968 Brazilian movie "Roberto Carlos em ritmo de aventura" when a pilot flow an helicopter inside the 250m (~ 820 feet) long Túnel Novo (New Tunnel) connecting the neighborhoods of Copacabana and Botafogo. https://youtu.be/ab8bVouGtwU https://youtu.be/ab8bVouGtwU Minute 0:57 to be more precise. Also, you can enjoy Rio de Janeiro from above in the 60s.
- daverol 5y ago
  There is a blog article about filming this (google translate available): http://culturaaeronautica.blogspot.com/2011/06/roberto-carlos-em-ritmo-de-aventura-o.html http://culturaaeronautica.blogspot.com/2011/06/roberto-carlo...
- rasz 5y ago
  What is funny you could still buy this helicopter, Schweizer 300, brand new up to 2002 as it was designed in 1955! ~Same carbureted engine with zero automation and 40L/h fuel consumption. No engine governor means pilot manually controls engine rpm, you are the ECM having to correct for air temp and pressure altitude, worry about icing and manifold pressure. All thanks to stupid US aviation policies - recertification is so expensive nobody does it and everyone flies dangerous shitboxes despite >50 years of innovations.
muzani 5y ago
This thread fills me with horror. I admire that movie, it's incredible, especially when I know it's just safe reenactment of a scene. But it's an uneasy feeling to know that there's some serious risk involved.

by themgt 5y ago

deleted 5y ago

[deleted]

jandrese 5y ago

That is an incredible feat of flying. I would be terrified of some kind of reverse ground effect from the road overhead. It's basically a 1990s version of barnstorming.

lisper 5y ago
From TFA: "I was curious about how the overpass would affect the ground effect of the helicopter. Tragically, I have no brain for physics. But I do know a helicopter pilot, so I asked him. Apparently, at 60 kts, there wouldn’t be significant ground effect because the down flowing air off of the rotor disk would mostly be tailing off of the helicopter. Had Tamburro taken the stunt slower, the down flowing air would be more directly underneath the helicopter, creating an (obviously undesirable) effect."
- jandrese 5y ago
  That part was talking about the traditional ground effect. There isn't much study about what happens when you have a ceiling over a helicopter because that doesn't happen very often in real life. Note the discussion of the air flowing off of the blades. I was thinking more of the low pressure zone above the helicopter being disrupted by the overpass. Apparently it wasn't too bad since the pilot managed the stunt twice without injury, but it's a possibility that would have had me crapping diamonds if I were asked to pull it off.
  - lisper 5y ago
    I feel an aircraft-on-a-conveyor-belt moment coming on. So first of all, GE in a rotorcraft is different from GE on a fixed-wing aircraft. The fundamentals are the same, of course, but in a rotorcraft the relative velocity of the blade/wing isn't connected to the velocity of the airframe the way it is in a fixed-wing aircraft. In a fixed-wing aircraft the velocity of the wing and the velocity of the airframe are the same, of course. But in a rotorcraft things get very complicated. The upshot of all this complication is that the GE effect is reduced as the rotorcraft's airframe starts to move. The faster it goes, the less GE you have. So you might notice some differences while hovering under an overpass, but shooting through at 60 MPH the GE is effectively a no-op. If you really want to know the gory details you'll have to read up on helicopter theory. It's way too complicated for an HN comment.
    - ambicapter 5y ago
      He's not talking about ground effect, he's talking about the overpass above the blades "cutting off" available air for a second.
      - lisper 5y ago
        Yes, I get that. "Reverse ground effect" was how the OP phrased it. What exactly do you think would happen in that case? Suppose the available air were "cut off" by the overpass (it wouldn't be, but let's suspend disbelief for a moment). What would be the result?
        jandrese 5y ago
        Loss of lift due to the interruption of the airflow causing the helicopter to crash into the ground at speed? Or suddenly lower pressure above the helicopter causing it to be "sucked up" into the ceiling. I think the pilot is probably correct that the stunt could only be pulled off at a higher speed where you can outrace the low/high pressure zones the blades are creating.

coldcode 5y ago

If people survive such a crazy stunt, you congratulate them, if not, you bury them and the director. Risking people's lives for a few seconds of film is not worth it.

capableweb 5y ago
I'm fairly sure the people doing these stunts do them because they love doing them, not because they are being forced to perform them. If people want to risk their lives for a few seconds of film, why stop them? People are into all kind of weird stuff, as long as they don't hurt others, I don't see what the problem is.
- ashtonkem 5y ago
  Reality is far more complex than that. Yes, stunt people tend to be a risk seeking crowd. But there’s also the risk of losing their livelihood if they refuse a director’s demands. Film business is a precarious way to make a living, and the power gulf between the director and the stunt person is massive. History is full of “I think this is a bad idea, but I’ll do it” accounts in the after-disaster reports. People can and regularly do dangerous things against their better judgement because they were ordered to do it or otherwise pressured into it. Saying that they volunteered is to drastically over simplify the situation.
  - capableweb 5y ago
    So again, they chose between doing stunts or doing something else. You don't work to do the stunts in the movie? Fine, don't work on the movie, it's not essential to life anyways so continue on with your life.
    - ashtonkem 5y ago
      Continue with your life, and risk losing your career. I think if you’re not accounting for this risk in how people think, then you are absolutely misunderstanding what motivates people to do what they do. Again, people regularly do things against their best judgement because of social and economic pressure. Stunt people are not magically excluded from this process.

russdill 5y ago

Seems like if you just wanted the side shot and not the straight on shot as well, you could of just pulled the helicopter on a low trailer using the median partition to block. The straight on shot would of required deleting the trailer which may have been difficult but certainly would look better than any CGI attempt

capableweb 5y ago
Or just CGI. But as Cameron himself puts it (copied from the article linked in parent): > we could’ve run a CG helicopter under the freeway overpass, but it was so much more fun to do the real thing. I'm guessing the same applies from pulling a helicopter on a trailer. It's simply not fun.

ghoward 5y ago

As an aspiring helicopter pilot, I am both awed and repulsed. Vietnam was something else for helicopter pilots. That level of skill would be hard for a perfectly-programmed autopilot to do. With regards to Vietnam, a legend that I was told (but cannot confirm) was that Hueys had such bad tail rotor authority that they would take off straight up with the whole airframe spinning. Once high enough, the pilot would start the helicopter moving forward, which would allow the tail rotor to bite more, and the helicopter would stabilize. Crazy if true. And after seeing a stunt like that by a bona fide insane and top-tier veteran pilot, I believe the legend.

naikrovek 5y ago
literally any Vietnam documentary would prove that wrong. what does "moving forward" even mean when you're spinning? also, forward movement doesn't give the tail rotor any more "bite" ... if anything, it would get less. moving in a consistent direction would tend to orient the body of the helicopter to face into the wind because of the wind vane effect.
- nwallin 5y ago
  While hovering, the tail rotor is pushing air into a dirty vortex. A small amount of speed, even just 20kt, will clear that vortex and give more authority. Even today helicopters will begin pitching nose down immediately on takeoff to get airflow cross both the main and tail rotor to clear those vertices. That being said, I've talked to a few Vietnam helicopter pilots and all of their stories were ... well, exaggeration is a common theme.
  - naikrovek 5y ago
    pitching the nose down certainly does one thing: it pushes air backwards, meaning the helicopter starts moving forwards. the air moving across the body of the helicopter, rather than down it, is what starts the wind vane effect. if the pilot tipped the helicopter to the right after leaving the ground, and then continuously held the control stick in the direction of the movement of the helicopter, the body of the helicopter would begin to face the direction of travel unless the pilot actively countered that turn via the tail rotor.

marcodiego 5y ago

Something a bit crazier was performed in Brazil in the 60's for a film: https://youtu.be/rSH3FVzcDSo?t=519 https://youtu.be/rSH3FVzcDSo?t=519

chrisgd 5y ago

Not too long after two children and an adult actor were killed on the set of the twilight zone movie. https://en.m.wikipedia.org/wiki/Twilight_Zone_accident https://en.m.wikipedia.org/wiki/Twilight_Zone_accident

felipelemos 5y ago

This reminds me the 1968 Brazilian movie "Roberto Carlos em ritmo de aventura" when a pilot flow an helicopter inside the 250m (~ 820 feet) long Túnel Novo (New Tunnel) connecting the neighborhoods of Copacabana and Botafogo. https://youtu.be/ab8bVouGtwU https://youtu.be/ab8bVouGtwU Minute 0:57 to be more precise. Also, you can enjoy Rio de Janeiro from above in the 60s.

daverol 5y ago
There is a blog article about filming this (google translate available): http://culturaaeronautica.blogspot.com/2011/06/roberto-carlos-em-ritmo-de-aventura-o.html http://culturaaeronautica.blogspot.com/2011/06/roberto-carlo...
rasz 5y ago
What is funny you could still buy this helicopter, Schweizer 300, brand new up to 2002 as it was designed in 1955! ~Same carbureted engine with zero automation and 40L/h fuel consumption. No engine governor means pilot manually controls engine rpm, you are the ECM having to correct for air temp and pressure altitude, worry about icing and manifold pressure. All thanks to stupid US aviation policies - recertification is so expensive nobody does it and everyone flies dangerous shitboxes despite >50 years of innovations.

muzani 5y ago

This thread fills me with horror. I admire that movie, it's incredible, especially when I know it's just safe reenactment of a scene. But it's an uneasy feeling to know that there's some serious risk involved.