Sign in to follow this  
Guest ElliotMV

One Engine Taxi B757-200

Recommended Posts

I recently did a approach with one engine failure, after landing, the B757-200 would not taxi like normal. I hope theres a fix for this, because you should be able to taxi on one engine. The airplane turned to the other direction to which I was taxing.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

There is nothing in the book that would suggest using the counter rudder on the ground for taxing after and engine failure. I will try what has been suggested. But, the B757-200 should be able to taxi on one engine without any problems.

Share this post


Link to post
Share on other sites

Mmm, my friend, it's simply physics. Asymetrical thrust causes these issues you know. Real pilots taxi on one engine with slight tiller pressure in the opposite direction of the running engine to cancel the effects of the asymetrical thrust. Wow..

Share this post


Link to post
Share on other sites

Hi Shane,"Mmm, my friend, it's simply physics."Yes - in the real world - but sometimes not in the FS9/PSS world. I'll send you details from testing.RegardsJohn R

Share this post


Link to post
Share on other sites

I should be able to offer an explanation of why things don't always work correctly on one-engine taxis, though with the exception of turns INTO the running engine, they should.Because FS9 has such terrible rolling friction, it requires us to keep constant thrust on to maintain forward momentum. In reality, a 757 can run its engines up to breakaway power (usually 40% N1 or 1.1 EPR) to get the aircraft rolling and then reduce to ground idle, and the aircraft will keep its momentum with idle thrust. This means if they want to turn the plane, even on one engine, they can do it without having to oppose thrust from the running engine.In FS, we have to keep that running engine spooled up and creating (a lot of) thrust to keep moving forward. This means, if #1 is running at 45% to keep moving, and you want to turn left, you have to fight 10-12000lbs of thrust to do so. Unfortunately situations such as THIS are NOT fixable in FS9. There is a file that fixes the stock rolling friction (sim1.dll) but it's illegal for big developers such as PSS (or any of the big names) to use as it's an edit/hack to copyrighted Microsoft material. So we're forced to work with what we have, which causes us to have the sliding effect on the ground, and the very high rolling friction.

Share this post


Link to post
Share on other sites

Thank you for such a great explantion of the problem. You would think that Microsoft would be happy to share all the files associated with the development of FS9 or FSX, plus great add-ON like PSS B757-200. It makes it hard to train like the pros, with this one disatvantage. I have noticed alot of differences from the real world vs Flight simulator, but I thought the major developers had all the reasonable access, so they could develop an excellent product.But my assumptions have got the best of me.

Share this post


Link to post
Share on other sites

Shane,Very many thanks for that. So for ElliotMV {and anyone else who has the problem} its nothing to do with the PSS aircraft

Share this post


Link to post
Share on other sites

Speaking purely on my own accord and for own personal uses, I've tried the community-altered sim1.dll file that sets rolling friction at realistic levels and it was incredible. One could run the engines up to breakaway power, get speed, and reduce the idle again and the aircraft would keep rolling without more thrust being needed. There was much improved sideforce on the tires so the slipping and sliding on the takeoff and landing roll was erradicated.The problem is, when you offer someone this file to use, it affects the entire stock of FS aircraft that everyone has ever made. I can set up my FDE so that it's compatable with the rolling friction fix, but every other aircraft you fly will start acting crazy. Idle thrust on a stock plane would be nearly enough to takeoff with if using the rolling friction fix because those FDEs had to be set up with SO MUCH thrust on the low end to counteract the bad rolling friction, you'd have to ride the brakes at ground idle just to keep the aircraft slowed up.FYI: During the 777 prototype tests (real life), it reached over 30kts on idle thrust alone while taxiing. ;-)

Share this post


Link to post
Share on other sites

This is great information, but what can developers do, to fix this problem. I would think Microsoft, Boeing and all the others, have this program fix in their simulators. So the fix in a pc simulator, should not create such a problem.Q. Can't FS developers create their own version of this file to work with all airplanes for simulation ?Q. Can FS developers change the limitations of the program code or write a compatiable code that works in concert with what's already been developed?

Share this post


Link to post
Share on other sites

All those .dll files are property of Microsoft. They can't be altered in any way. Doing so would open up a legal can of worms. The way they see it, it'd be like taking a classic novel, changing a few paragraphs, and re-releasing it. For personal use is one thing, but we're taking a piece of Microsoft proprietary stuff and re-releasing it.I think it's a shame but it's been told to me that developers aren't allowed to redistribute this altered file legally.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this