Simviation Forums

Hi guys(/gals?),

I'm currently flying the default 747-400 on a Manchester (UK) to Dulles transatlantic run, just reached FL400 on autopilot.  Climb rate set for 0, IAS set for 0.85M, so in theory the aircraft should be level.  However the autopilot insists on maintaining 5 degrees of elevation to the nose, which looks completely wrong.  How can I get the autopilot to level the plane while maintaining height and airspeed?

No flaming please, I'm still learning (this is my first long haul flight in a Jumbo)

Regards

Seb

all aircraft must maintain a slight pitch up altitude in order to keep a certain altitude dude.. its dynamics, everything is fine

But 5 degrees?  It seems a little excessive.  And I'm at cruising speed and altitude for the 747-400 so its not as if I need to slow down or anything like that.

That's FS9 for you i'm affraid. Some AC have the wrong center of gravity built in and this won't allow it to cruise level.

greenhorn, 40,000 is high, maybe try 35,000 or so? On the real thing pilots often level out at a lower altitude early on, and stay there until they've burned off some of the fuel. And 0.85 is practically max. speed - check the N1 engine gauge, it should only read about 65% in cruise; it may be that the engines can barely generate enough power to maintain both max. height and max. speed, and the autopilot has no option but to hold the nose up.

Also consider checking the expected fuel consumption in your Flight Plan, and off-loading some for shorter trips. a 747 wouldn't require anything like full fuel just for the Atlantic. Easily done, press 'Alt/Aircraft/Fuel/Fuel' and zero some of the tanks. Aim for maybe 120% of what the Flight Plan says you'll need, to give you a reserve - and also keep at or below the speed the Flight Plan recommends.

You'll probably still get a bit of 'nose-up' early on but the tendency will decrease as the fuel load lightens.

[quote]But 5 degrees?

If your very worried (which u shouldnt be) my friend has a trick that if u put a degree or two down in flaps, then the plane will level. The only problem is that your engines might work harder and u might burn more fuel...

Nick

If your very worried (which u shouldnt be) my friend has a trick that if u put a degree or two down in flaps, then the plane will level. The only problem is that your engines might work harder and u might burn more fuel...

Nick

BAD IDEA!  Extending ANY flaps at that kind of speed will cause them to rip off.  Do NOT extend flaps above their limit (or gear, those will become damaged above their extension speeds too)

BAD IDEA!  Extending ANY flaps at that kind of speed will cause them to rip off.  Do NOT extend flaps above their limit (or gear, those will become damaged above their extension speeds too)

Very Bad Idea in real life indeed. But in FS, a sim that boasts to be "As Real As It Gets", it's very possible and brings no bad effects beside the need for more fuel.

If it really bothers you, go into the "Fuel and Payload" menu and shift some pax around... move all the fatties up front.

That might do the trick, although the sim isn't perfectly accurate.

To fly at 40000 feet without going up or down with the nose facing completely level would require an Angle of attack of 0 degrees, which NO aircraft can do or will do without pushing the nose down.

Go down to FL350.

[quote][quote]
BAD IDEA!

There is no such thing as a bad idea in  fs2004

FL40 is TOO high for your a/c. The AP is maintaining an attitude of 5 deg in order to maintain sufficient lift over the flying surfaces.
You need a much lower FL. Also what is your airspeed?
above FL240 you should be using your mach meter and not IAS. If your airspeed is too low the AP will compensate to maintain straight and level flight by increasing the angle of attack. It will go on doing this as you slow down until the wing stalls.
If you are flying the correct speed profile on descent, approach and landing you will notice that when you deploy the flaps the angle of attack reduces each time because your wing had increased in area and therefore can fly at a lower incidence.
Please check your flight manual for each a/c you fly. Your Mno Vno Vne and Mne define the upper limits of your flight envelope. Staying within these limits means the a/c will stay in one piece
Vololiberista

FL400?? That's quit high!

I always fly my 737 at FL270 because over it you have to slow down.

@vololiberista: Why do I have to use the mach above FL240? I always asked myself why it is there. My general airspeed on FL270 is about 330 KIAS. Is KIAS the same as knots?

I think I have to fly more... :-/ :-/