Ok, this one took me a little bit longer. About 10 minutes.After reading the business about the 747 doing loops in XP10, I decided to have a look at the acf. Saw a few issues, modded them, and here you go.I haven't THOROUGHLY tested it, but it's definitely harder, if not impossible to do a loop.Just drop it into the 747-400 United folder.Feedback welcome.To download it, right click the link, select "Save as..." and start downloading.http://dl.dropbox.com/u/1192596/747-400%20United.acf

Defiantly forced me to make the loop more precise. Did you just lower the G-Tolerance?It's nice because now we can see clearly why XPX is better then FSX. Also this time I did the loop at 600 feet to really test the limits.

Edited February 6, 201214 yr by Johnny Thunder

I have the documentation on a 747 flight model, but it's buried somewhere among the 8GB worth of reference material I have on the thing. I know where the problems MIGHT be. I'd rather not say what I did, but I'll upload a new acf file in a few minutes.

In FSX the thing would do the first half of that loop all right (Just like in the picture), but the second half it would have just dropped like a rock.

Edited February 6, 201214 yr by Johnny Thunder

Ok, re-download the acf file in the 1st post. I tested it this time. Couldn't loop it.

In FSX the thing would do the first half of that loop all right (Just like in the picture), but the second half it would have just dropped like a rock.

And in FSX you can land the 747 on an aircraft carrier and if you watch the video till the end, you can click a link that shows a 747 taking off from an aircraft carrier in FSX.. Let's keep the comparisons to a minimum, yes?

http://youtu.be/NntjDsONtF0

BTW, the 747 doesn't just drop like a rock. There was a well known case of JAL 123. A Boeing 747 that lost all pitch control through total hydraulic fluid loss. It started going through phugoid oscillations (pitching up until it slowed down so much, the wings couldn't keep lift, then the nose pitched down and built speed up again.) It did this several times until it finally crashed.So if the FSX 747 goes through the first half of the loop, and then drops like a rock, then the flight model is flawed. In X Plane, the 747's nose starts to drop and slowly builds up speed again. At least my modded one does. And if you don't touch the controls, the nose will start to pitch up again as airspeed increases. Just like in the RW.

This time I pulled out about even where I came in, it defiantly fell more like a rock but that might have been me too.You are making me a better Jedi... I like this.

I'm not going to spend my time modding a default 747 to make it fly exactly like the real thing. For 15 minutes work, it's good enough. I tried 6 times to loop it and couldn't do it. I'm interested in feedback from more people. How about you post your "loop entry speed", weight, fuel, and anything else that can help to determine why I can't loop it and you can.

Ok, re-download the acf file in the 1st post. I tested it this time. Couldn't loop it.And in FSX you can land the 747 on an aircraft carrier and if you watch the video till the end, you can click a link that shows a 747 taking off from an aircraft carrier in FSX.. Let's keep the comparisons to a minimum, yes?

http://youtu.be/NntjDsONtF0

BTW, the 747 doesn't just drop like a rock. There was a well known case of JAL 123. A Boeing 747 that lost all pitch control through total hydraulic fluid loss. It started going through phugoid oscillations (pitching up until it slowed down so much, the wings couldn't keep lift, then the nose pitched down and built speed up again.) It did this several times until it finally crashed.So if the FSX 747 goes through the first half of the loop, and then drops like a rock, then the flight model is flawed.

The FSX 747 didn't drop like a rock. It decended nose high, with the yoke pulled all the way back..................just as the plane of mine, would do with just me aboard. Most default FSX aircraft will also do the oscillations. I didn't try different power settings. But regardless, I certainly won't be depending on FSX or X-Plane to see what the real one will do!

Hang on, Larry. You're saying when the airspeed drops so far, that the aircraft stalls completely, even in your Vans RV6, if you keep the yoke pulled all the way back during the stall, the nose will continue to pitch up???

Well, lets see. I do that loop by first taking off and keeping the plane low to the ground on full throttle until it hits 360knots. I don't change the trim so I hold the joystick forward.When I hit 360 knots I gently but quickly relieve pressure on the stick and start up into a climb, as the plane starts to lose airspeed I pull back on the stick to maintain the same acceleration of angel of attack that was given to me by the boost of revealing pressure on the stick at 360 knots. As the speed gets bellow 300-200 knots I SLOWLY start to pull the joystick into my lap and start to really push the plane to it's limits in the loop.At around 70 knots the plane should be at the top of the arc, upside down, and the yoke is in the lap.Once the plane starts to point down again, it might be a good Idea to cut the throttle, or not. Play with it. The rest is just a typical recovery from that point.

Edited February 6, 201214 yr by Johnny Thunder

360kts at just above sea level.... :LMAO:If you're going to take it to such an extreme, (which would NEVER happen in the real world) then wait until I finish the 747 for X Plane some time later this year or next year.I don't even think that's been simulated for real world pilots...360kts at just above sea level.

You just gotta think of airplanes like roller coasters.

Well, if I load the plane up to maximum load 360 knots is not enough speed to really do a loop. It dose something that is almost a loop, but isn't.To do a loop in this 747 mod at full load, it seem you need to be going about 400 knots to do anything that can be called a loop, and even then it's a bit lame.You are gonna lose about 1000 feet if you do full load loops, so you should only do these full load loops above 2000 feet to play it safe.

Edited February 6, 201214 yr by Johnny Thunder

The 747 was not originally designed to be a passenger aircraft. It was originally designed to be a heavy lifter for the U.S. Air Force. One of it's requirements was to be a S.T.O.L. capable aircraft. The video depicting the landing on the carrier... none of us know what the loadout was (pax/cargo/fuel). An empty 747 could very easily come down onto a carrier's deck. It wouldn't stop in time (but then neither do any other jets, hence the trap wires). However we all know ground braking in either sim can be very unrealistic.Oh... as for it being used by the Air Force... It lost the contract bid to Lockheed Martin. The Air Force chose the C-5 Galaxy.The fact this 747 is looping in X-Plane indicates either the person has reality settings dumbed way down (no g-forces ripping wings off??) or the flight dynamics is intruducing lift where none should exist.

There are two, possibly three areas that need to be adjusted in the x plane 747. I adjusted 2 of them, (both contribute to a 747 being able to do a loop), and now, under normal flight operations, I cannot loop it. But let's face it, doing 360kts at just above sea level, where the air is most dense, (providing the most lift) it's hardly surprising he did a loop. I don't know about FSX, but in x plane it is possible to adjust ground friction in Planemaker. No plug ins required.Something interesting I found..."Looping a 747 or a DC-10 would be trickier still. You'd have the problem of lift again, at the moment when the tail is down, but it would be harder to overcome, since the plane must be climbing, not merely maintaining its altitude, at the same time. One way to get a plane to climb is to make it go faster (increasing the speed increases the air pressure under the wings, which is what holds the plane up in the first place). But there's some doubt as to whether a 747 or a DC-10 could achieve enough forward speed to deliver the extra shot of lift that a loop would require. Boeing suspects its planes could make it, but since no one has ever been silly enough to try, there's no way of knowing for sure. ""We put this firstly to Disk Schleh, of Boeing Commercial Airplanes in Seattle, WashingtonWell a large passenger jet such as the Boeing 747 or almost, almost any large passenger jetliner was not designed nor was it tested, nor was it certified to perform aerobatic manoeuvres like a loop-the-loop or a barrel roll.Certainly the wings of the airplane would be put under quite a bit of stress and some of the tail structure and so forth, doesn’t mean it couldn’t do it but they were not designed that way and they were certainly not certified with that in mind.