November 14, 1997
WebChat with Chris Sweeney

Flight Simulation Engineer
Verticle Motion Simulator
Ames Research Center, Moffett Field, California

[ Susan/NASAChatHost - 5 - 10:24:23 ]
Welcome, Keith, Are you interested in flight simulators?

[ Jason-Jason/AdvancedTechnologiesAcademy - 7 - 10:29:46 ]
Hello there, I'm Jason from the Advanced Technologies A

[ Chris/Ames - 8 - 10:30:02 ]
Hello, Chris is ready to answer any flight simulation questions.

[ Chris/Ames - 12 - 10:32:16 ]
RE: [Keith/DeAnzaCollege] Chris: What can you tell me about the flaws in the Design of the Harrier Junk Jet and How did you use the simulator to overcome the orriginal design flaws.
Keith, The Harrier "Jump Jet" (I am not sure the designers would like the junk name) is a very different fixed wing aircraft in that it can hover (no forward speed). Simulators allow designers to test new and better ways to maneuver the Harrier at these slow speeds.

[ Chris/Ames - 14 - 10:33:46 ]
RE: [Jason/AdvancedTechnologiesAcademy] Chris: Do you believe that simulation help save lives.
Jason, Yes, sims definitely save lives. We can do things in sims that would be far too dangerous in the real world, and if the pilot "crashes" the sim, we can just start another run wiht no injuries to anyone.

[ Chris/Ames - 17 - 10:35:31 ]
Keith, We are currently studying a high speed civil transport that may fly at 70,000 feet at Mach 2.4 and get you to Tokyo in 4 hours instead of 14.

[ Chris/Ames - 21 - 10:37:30 ]
RE: [Jason/AdvancedTechnologiesAcademy] If passsenger aircrafts ever begin to fly in the upper atmosphere, would the simulations for those planes need to be programed any differently?
Jason, The upper atmosphere is a little different from "sea level" type applications, but there are still equations that describe how a vehicle would move and the vehicle control system would be simulated the same way. There are space shuttle sims that have on orbit scenarios.

[ Chris/Ames - 24 - 10:39:43 ]
RE: [Megan/DenverElem-MeganDuMarr/DenverElem] Chris: I read in your bio that you use some kind of special software to put pieces of an aircraft together. This sounds totally cool! What kind of software is it?
Megan, We use Fortran to describe most of the aircraft models, but we have an in-house developed operating system and system software which allows us to modify a wide variety of parameters (altitude, flight control system gains, etc.) on the fly to give the pilot a completely new task and plane within seconds.

[ Chris/Ames - 25 - 10:41:04 ]
RE: [Keith/DeAnzaCollege] In you Bio you say that you read other peoples Biographies. Could you be more specific.
Keith, The bios I particularly remember were Ted Williams, the Boston Red Sox player, who also flew in WWII and Korea. This combined my interest in sports and flying.

[ Chris/Ames - 27 - 10:42:31 ]
RE: [MeganDuMarr/DenverElem] What is your favorite aircraft to simulate and have you ever flown it in real life?
Megan, I like "simulator flying" all of the simulations I work on (Space Shuttle, High Speed Civil Transport, Harriers) but I think I like the Space Shuttle best because it is a space plane and an aircraft.

[ Chris/Ames - 29 - 10:44:21 ]
RE: [Keith/DeAnzaCollege] How are you dealing with "STRESS" on the structure of future designs of Aircraft. In the early days of Aircraft design this was a fatal mistake for the Commerical Aircraft in Great Britian.
Keith, We deal with the stresses in a variety of ways. Mostly, the designers can look at stress buildup on a wing in a non real-time environment. They know the forces exerted and the material strength. In sims, we look at how this would affect the flying qualities of the aircraft.

[ Chris/Ames - 30 - 10:45:57 ]
RE: [Jason/AdvancedTechnologiesAcademy] Is there any way that the simulator can give the pilot the experience of multiple G's?
Jason, Most simulators have a hard time with multiple G environment. There is just not enough travel or space to give the pilot that feel. There are simulators that are large centerfuges which can give pilots large G's.

[ Chris/Ames - 33 - 10:47:47 ]
RE: [Keith/DeAnzaCollege] Are the type of simulators used at NASA used to test a pilot's skill or are they used solely for design?
Keith, Some simulators mostly military do the dog-fight and skill training. The simulator I work on is mainly for design and handling qualities work, although we do train astronauts.

[ Chris/Ames - 35 - 10:48:58 ]
RE: [MeganDuMarr/DenverElem] Your bio doesn't say anything about whether or not you're a pilot. Are you? After working on "simulator flying" all day I'd want to get out and do the real thing!
Megan, I absolutely want to fly a real thing after being in the sim. I have not taken the time to get a pilot's license yet, but that is in the plans for the future.

[ Chris/Ames - 36 - 10:49:52 ]
RE: [Jason/AdvancedTechnologiesAcademy] Did you simulator play any part in the design/testing of the new F-22 fighter.
Jason, No, we did not do any F-22 simulations. That is more of a classified program and we only work on a few of those.

[ Chris/Ames - 38 - 10:51:15 ]
RE: [Jason/AdvancedTechnologiesAcademy] In a simulator are the preset weather conditions that you may choose from, or must you program new conditions for every new aircraft?
Jason, Every program has different requirements for weather. We have quite a large capability to modify visual range, clouds, wind, turbulence, time of day, rain, etc.

[ Chris/Ames - 42 - 10:53:54 ]
RE: [Keith/DeAnzaCollege] When you see Flight Sims at the Video Arcade-and these days they are becoming very sophisticated-are they even close to what you use at NASA?
Keith, Flight sim video games are getting very good. The processors that drive them are getting faster all the time. What we gaurantee is that the pilot will see up to 4500 polygons drawn on 6 channels every .016 seconds and new forces and accelerations to react to every .01 seceonds which no arcade game can come close to. The Magic Edge in Mountain View is closer to what we do.

[ Keith/DeAnzaCollege - 43 - 10:55:04 ]
What do you consider you best accomplishments and have you won any awards at NASA?

[ Chris/Ames - 44 - 10:55:49 ]
RE: [Joe-Joe/VIS] have you ever played around with the United Airlines simulator in Denver? Is it anything like the environments you use?
Joe-Joe, I have not been to the Denver sim, but some people who used to work on our sim now work there. It is a training simulator with more limited travel than we have and can only do 737s, 747s and the like whereas we do all kinds, but it is very similar.

[ Chris/Ames - 47 - 10:57:39 ]
Keith, The best accomplishment and award I have received is the Manned Flight Awareness award given by NASA for work on the Space Shuttle. We worked on a software fix for a landing problem and I got the award and got a chance to go see a Space Shuttle launch from the VIP section. It was amazing.

[ Chris/Ames - 49 - 10:59:55 ]
RE: [Jason/AdvancedTechnologiesAcademy] Have you ever worked on simulations that are run any faster than 100Hz?
Jason, The pilots who fly are sims are the test pilots who will fly the real vehicles. Our sim runs can last anywhere between 30 seconds and 45 minutes depending on the sim. Our fastest sim at the moment is a BlackHawk helicopter that runs at 200 Hz.

[ Chris/Ames - 51 - 11:01:03 ]
RE: [Keith/DeAnzaCollege] Is the Simulator expensive to maintain and is the Simulator updated with new technology on a regular basis?
Keith, The simulator motion system is a very impressive machine that is fairly expensive to use, but compared to flying a real aircraft it is incredibly cheap.

[ Chris/Ames - 55 - 11:03:17 ]
RE: [Keith/DeAnzaCollege] Is there any plans for the commerical airlines to ever consider commercial craft traveling beyond Earth. Say to an Orbiting Station? And would you be involved in the design of such craft?
Keith, Lockheed is currently working on VentereStar which is supposed to be a Space Shuttle replacement. This will takeoff by itself from a runway and return to land. In 50 years or so, I could see that technology moving to the airlines. I would love to work on something like that.

[ Chris/Ames - 57 - 11:05:13 ]
RE: [Traci-Traci/Hometaught] I was wondering if Chris Sweeney has ever flown an airplane or a jet. I never thought I'd be asking any of these questions or even try talking to any of you.
Traci, I am glad to be able to "chat" with you. I have flown airplanes before. In college, one of our classes was about flight testing and we got hands on time in a small Cessna. I had roommates in college who are now flying the B-1B, T-38 and C-130 aircraft and sometimes I wish I could join them.

[ Chris/Ames - 60 - 11:06:29 ]
RE: [Keith/DeAnzaCollege] Do you help design some of the Early Warning Detection Systmes that we hear so much about. Are they part of the Simulator?
Keith, We usually do not work on warning systems, but can implement them if the researcher needs to.

[ Chris/Ames - 63 - 11:07:44 ]
RE: [Keith/DeAnzaCollege] How do pilots rate Simulators in general?
Keith, Pilots generally do not like the simulators, because they love to fly the real thing! Otherwise, they all say they would rather fly the sim than do anything else.

[ Chris/Ames - 64 - 11:08:50 ]
RE: [Traci-Traci/Hometaught] I hope you got my other message. They say that you can make about 3-4 airplanes in a year, but I want to know what the most airplanes anyone has made in a year would be.
Tracy, We do 3-4 simulations a year, but we do not make the planes. I heard during World War II that some factories were making over 1,000 planes a year.

[ Chris/Ames - 68 - 11:11:18 ]
RE: [Keith/DeAnzaCollege] What percentage of Design Aircraft and or there applications make it into the Commercial sector?
Keith, There are more now than there used to be, kind of. In the 1950s, designers would build a prototype, get a test pilot and fly to see if the plane would work, so there were a lot of different planes built. Now, that would be too expensive, so more simulations are done to test the designs and fewer different aircraft are actually built.

[ Chris/Ames - 70 - 11:12:57 ]
RE: [Traci-Traci/Hometaught] How high did you get to go in the airplane? Was it fun? I've rode on an airplane before and it was fun, but I've never controled one. Of course I'm only 12, and I wouldn't be able to any way.
Traci, On the aircraft I flew, we only went up to 5,000 feet. An airline flight usually flies at around 37,0000 feet. Since you are 12, maybe when you are 25 you can fly to outer space.

[ Chris/Ames - 74 - 11:14:36 ]
RE: [Jason/AdvancedTechnologiesAcademy] How long can an airplane fly on a full tank?
Jason, That depends on the airplane. Some are designed for long duration and some for speed. For example, Burt Rutan designed a plane that flew all the way around the world on one tank. The SR-71 spy plane needs to re-fuel as soon as it takes off, but it can go Mach 3+.

[ Chris/Ames - 76 - 11:16:06 ]
RE: [Keith/DeAnzaCollege] Do you forsee a time when there will be a commerical aircraft that is piloted by computers and a pilot would be on board as a precautionary mesure?
Keith, You would be surprised how much time pilots on commercial airlines spend actually flying and how often the computer or "auto pilot" is flying. The pilots take-off and land, but most of the rest of the time the computer can be flying.

[ Chris/Ames - 79 - 11:17:05 ]
RE: [Susan/NASAChatHost] Chris, What are you working on now?
Right now, I am completing the report for the HSCT (hish speed civil transport) and am beginning to work on the Space Shuttle.

[ Chris/Ames - 81 - 11:18:21 ]
RE: [Traci-Traci/Hometaught] How old are you and how many friends did you have in college? What part of college did you like best? If I were in college I would have liked the flying the best because I like to be up high.
Traci, I am 32 years old and had lots of friends in College. It was a big place. Many of them were interested in flying, too, that is how I know people who fly.

[ Chris/Ames - 83 - 11:19:34 ]
RE: [Keith/DeAnzaCollege] Are Airplanes they only craft that you simulate flying? ie rockets, missles, helicopters, etc
Keith, We simulate many kinds of fixed wing airplanes, helicopters (BlackHawk, Apache, Comanche) and other things. We have done cars, blimps, and a bobsled.

[ Chris/Ames - 84 - 11:20:52 ]
RE: [Traci-Traci/Hometaught] Do you like computers? I heard that you work on them to make stuff like your projects.
Traci, Yes, computers are fun. They can do many things that people cannot (like solve equations very quickly). Working on computers and programming them is like fixing problems and I like to do that.

[ Chris/Ames - 87 - 11:22:40 ]
RE: [Jason/AdvancedTechnologiesAcademy] I have hear of work on a commercial aircraft that will travel at a little more that mach 2, is this true, do you have any part in the simulation for this?
Jason, Yes, that is the HSCT (high speed civil transport). It will be able to go Mach 2.4 with 300 passengers for 5,000 nautical miles.

[ Chris/Ames - 89 - 11:23:51 ]
RE: [Susan/NASAChatHost] Chris, Will the astronauts come a fly the VMS?
Yes, All of the pilot astronauts fly the VMS sim twice a year. It is the only place they get realistic landing practice.

[ Chris/Ames - 91 - 11:25:29 ]
RE: [Traci-Traci/Hometaught] My step-dad was in the army and he flew alot of planes. He said it was cool. I'm not very good at flying a computer graphic airplane so I don't think I would be able to fly a real airplane, but you never know.
Traci, If you really want to fly, you can work towards making it happen. Just because you are not good at games, does not mean you will not be good at the real stuff.

[ Chris/Ames - 92 - 11:26:29 ]
RE: [Keith/DeAnzaCollege] Do you think we are moving towards more craft that remble the Stealth, The flying wing design?
Keith, The flying wing design is good for some things, stealth and lower drag, but it is not as maneuverable as other designs.

[ Chris/Ames - 94 - 11:27:40 ]
RE: [Traci-Traci/Hometaught] That's great! We only have a few minutes left. Are you going to be on tomorrow? I know I will, and if you are I'll think of more questions to ask you unless you don't want any more questions.
Traci, I will not be on tomorrow, but you can ask Susan and maybe I can be on again sometime in the future.

[ Susan/NASAChatHost - 97 - 11:29:19 ]
RE: [Traci-Traci/Hometaught] That's great! We only have a few minutes left. Are you going to be on tomorrow? I know I will, and if you are I'll think of more questions to ask you unless you don't want any more questions.
Tracy, I am glad you enjoyed chatting with Chris, I hope he'll do another chat sometime. Check http://quest.arc.nasa.gov/aero/chats for the schedule.

[ Chris/Ames - 98 - 11:29:21 ]
RE: [Jason/AdvancedTechnologiesAcademy] Can your simulator be use in replace of a wind tunnel? How acurate are the physics of the simulator?
Jason, Our sims need the wind tunnels to produce the aerodynamic data we use to fly the aircraft. Maybe in the future the computers will be powerful enough to calculate the CFD of the plane and the physics, but we are not there yet.

[ Chris/Ames - 101 - 11:30:18 ]
RE: [Jason/AdvancedTechnologiesAcademy] Chris thanks for sharing your knowledge with us, we have enjoyed chating with you.
Jason, Thanks, it was fun chatting with you guys.

[ Chris/Ames - 102 - 11:31:13 ]
RE: [Traci-Traci/Hometaught] Where do you live and where were you born? I was born in Michigan. Have you ever made a project in Michigan?
Traci, I live in California near San Francisco. I have not done any projects in Michigan.

[ Susan/NASAChatHost - 103 - 11:31:35 ]
Thanks every one Chris has to go back to work now! Thanks for your awesome questions!! Please join us next time. Thanks Chris this was wonderful!

[ Keith/DeAnzaCollege - 104 - 11:32:11 ]
Chris: Thank you for taking the time to answer my question. Hope to talk to you online again.

[ Chris/Ames - 105 - 11:32:22 ]
RE: [Susan/NASAChatHost] Thanks every one Chris has to go back to work now! Thanks for your awesome questions!! Please join us next time. Thanks Chris this was wonderful!
Thanks Susan, I had a great time answering questions and talking with people.