Negative G possible in commercial airline simulator?
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Negative G possible in commercial airline simulator?
Is it possible to achieve this? If so what is the maximum period of time in a single attempt could be reached?
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If it falls off its jacks and onto the floor, perhaps. Otherwise, not really. The exaggerated tilt will give you a pretty good sensation of acceleration or deceleration, but not "negative G" in its true sense.
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No. Not possible.
It's just a box, bolted to the floor, with six hydraulic jacks in between.
It creates the sensation of acceleration by tilting the box backwards while keeping the vision constant. Your eyes don't register a change, but you get pushed back in your seat, so your brain interprets that as linear acceleration, which it isn't really.
All other sensations are created the same way.
So while it can create an instantaneous jolt to register a rough landing or simulate turbulence, it can only do so for a very short period which is limited by the travel of the jacks. So it can't, for example, even simulate the two gs you would experience in a constant 60 degree angle of bank turn. It can simulate the stick forces, but not the g.
I've flown several jet simulators under the Sydney Harbour Bridge inverted, just for fun, with varying levels of success. While the "aircraft" is inverted, with all the visible cues you would get in an inverted aircraft, the motion just tends to give up past about 60 degrees of bank. Of course the sim is still right side up. It's actually an odd feeling. Your eyes telling you your upside down, but your butt telling you you're right side up.
Probably easier to just try it in the real aeroplane, no false sensations making it difficult. Now there's a thought. We'd make the news.
It's just a box, bolted to the floor, with six hydraulic jacks in between.
It creates the sensation of acceleration by tilting the box backwards while keeping the vision constant. Your eyes don't register a change, but you get pushed back in your seat, so your brain interprets that as linear acceleration, which it isn't really.
All other sensations are created the same way.
So while it can create an instantaneous jolt to register a rough landing or simulate turbulence, it can only do so for a very short period which is limited by the travel of the jacks. So it can't, for example, even simulate the two gs you would experience in a constant 60 degree angle of bank turn. It can simulate the stick forces, but not the g.
I've flown several jet simulators under the Sydney Harbour Bridge inverted, just for fun, with varying levels of success. While the "aircraft" is inverted, with all the visible cues you would get in an inverted aircraft, the motion just tends to give up past about 60 degrees of bank. Of course the sim is still right side up. It's actually an odd feeling. Your eyes telling you your upside down, but your butt telling you you're right side up.
Probably easier to just try it in the real aeroplane, no false sensations making it difficult. Now there's a thought. We'd make the news.
Last edited by IsDon; 5th Feb 2016 at 10:47.
Actually, minor exposures to negative g in a simulator are indeed possible and used all the time. The "box" can "squat" very rapidly and can induce negative g on the occupants inside - provides exceptionally accurate representation of turbulence, when immediately followed by the entire simulator "lifting" again and providing an equally short "burst" of positive g. Of course, we are talking about a half-second "burst" of negative/positive g, but it provides a high fidelity experience for those inside. This ability to move up and down very quickly is enhanced by the more recent use of electric servo jacks, instead of the original hydraulic ones - the electric jacks are a marvel to watch - exceptionally fast moving and almost completely silent. I'm always in awe of the smarts behind the movement of simulators and the resultant experience for the occupants.
Last edited by josephfeatherweight; 5th Feb 2016 at 22:10.
the motion just tends to give up past about 60 degrees of bank.
Student pilot crashes simulator
Florida Senital Star, 4 January 2008
In what may be a first in the aviation world a student has crashed a multi-million dollar simulator. Buba Jemmah came from Gambia in Africa with dreams of being an airline pilot, but his dreams came crashing to a halt only two weeks into a month long training process at SimFly in Florida when the simulator he was controlling rocked off its base and crashed to earth.
“This is unprecedented”, said James Tavern, president of Sim Fly. “Nothing like this has ever happened in the aviation training world. These things are bolted to the floor”.
The Frasca B737 simulator that crashed was a ‘full motion’ type, with computer controlled hydraulic legs that simulate the forces pilots feel when maneuvering. In addition it had complete simulation of views outside the windows, Air Traffic Control and accurate control forces. Full motion simulators mimic real aircraft so well that pilots trained in them become licensed to fly the real thing without ever setting foot in an airliner. The simulator carried a crew of three, Buba, Evin Shkey from England who was training for the first officer position, and the instructor who sat behind the pilots at his own station in the completely enclosed cockpit.
“Luckily no one was seriously injured” said Buster County emergency responder Hieronymous Crutch. “But all three were pretty shaken up because they weren’t wearing their seatbelts during the estimated ten foot fall.”.
No one really knows why the simulator tipped over, but from his hospital bed the instructor told FAA officials that Buba had been know to provoke the simulator into some pretty wild gyrations, and that today was no different. He is reported to have said, “personally, I wouldn’t let Buba pull my kid’s wagon”.
“I don’t think we will ask him to come back” said James Tavern bitterly. “We all liked him: he was a real gentleman with a great sense of humour. But basically we at SimFly are out of 2.5 million dollars because the Frasca was not insured. Who buys insurance for a simulator?”.
And that may not be all of Buba’s troubles. The FAA, the NTSB and Homeland Security have become involved because Buba allegedly cried ‘Ai-Yi-Yi-Yi’ as the simulator crashed, the cry of terrorists as they anticipate martyrdom. Homeland security is now concerned that Bubab may have been training for a terrorist attack using a simulator.
“Can you imagine the damage that one of these simulators could do if it were loaded with explosives?” said one Homeland security official. Buba was quickly whisked off to the Guantanamo Baby detention centre where Gambian embassy personnel will be able to write a letter to him in three years. The FAA has issued a Directive for the Frasca simulator effectively grounding the entire fleet until the cause of the crash can be determined.
Florida Senital Star, 4 January 2008
In what may be a first in the aviation world a student has crashed a multi-million dollar simulator. Buba Jemmah came from Gambia in Africa with dreams of being an airline pilot, but his dreams came crashing to a halt only two weeks into a month long training process at SimFly in Florida when the simulator he was controlling rocked off its base and crashed to earth.
“This is unprecedented”, said James Tavern, president of Sim Fly. “Nothing like this has ever happened in the aviation training world. These things are bolted to the floor”.
The Frasca B737 simulator that crashed was a ‘full motion’ type, with computer controlled hydraulic legs that simulate the forces pilots feel when maneuvering. In addition it had complete simulation of views outside the windows, Air Traffic Control and accurate control forces. Full motion simulators mimic real aircraft so well that pilots trained in them become licensed to fly the real thing without ever setting foot in an airliner. The simulator carried a crew of three, Buba, Evin Shkey from England who was training for the first officer position, and the instructor who sat behind the pilots at his own station in the completely enclosed cockpit.
“Luckily no one was seriously injured” said Buster County emergency responder Hieronymous Crutch. “But all three were pretty shaken up because they weren’t wearing their seatbelts during the estimated ten foot fall.”.
No one really knows why the simulator tipped over, but from his hospital bed the instructor told FAA officials that Buba had been know to provoke the simulator into some pretty wild gyrations, and that today was no different. He is reported to have said, “personally, I wouldn’t let Buba pull my kid’s wagon”.
“I don’t think we will ask him to come back” said James Tavern bitterly. “We all liked him: he was a real gentleman with a great sense of humour. But basically we at SimFly are out of 2.5 million dollars because the Frasca was not insured. Who buys insurance for a simulator?”.
And that may not be all of Buba’s troubles. The FAA, the NTSB and Homeland Security have become involved because Buba allegedly cried ‘Ai-Yi-Yi-Yi’ as the simulator crashed, the cry of terrorists as they anticipate martyrdom. Homeland security is now concerned that Bubab may have been training for a terrorist attack using a simulator.
“Can you imagine the damage that one of these simulators could do if it were loaded with explosives?” said one Homeland security official. Buba was quickly whisked off to the Guantanamo Baby detention centre where Gambian embassy personnel will be able to write a letter to him in three years. The FAA has issued a Directive for the Frasca simulator effectively grounding the entire fleet until the cause of the crash can be determined.
The "box" can "squat" very rapidly and can induce negative g on the occupants inside
The box drops with a resounding Bang with much noise and confusion, often severely frightening the horses up front.
