Simviation Forums

Hi,
I have FSX installed and I want to fly Learjet45 airplane.
My problem is that if I land using the autopilot when I touch down after the wheels touch the ground  the plane tends to takeoff again (while I revers thrust) and is very hard to stop it to the end of the runway.

I disconnected the autopilot before touch down.

What should I do to have a normal land with this plane.

Thanks,

Check if auto-throttle is disengaged - if you just hit 'z' for the AP the auto-throttle will remain engaged...

Make sure your spoilers are armed. If you start to take off again agter landing then you are going too fast. Keep it at 135 - 140 to land. Also check your trim while on final.

Your final approach speed (Vref) is something you'd know before flying the airplane, and will depend on your landing weight.. ( and you'll know what that is because of thorough flight-planning

Thank you for answers.
I think in my case the problem is the trim.
I'll check it and come back with an answer.

The original question:

What should I do to have a normal land with this plane.

Answer:

1) Be at a safe landing weight

2) Establish a stabilized approach well out, so that you're pretty much just waiting on the runway to come to you.

3) Be at Vref, with proper flap deployment on short final.

4) Hold the aircraft just above the ground until the the airspeed falls low enough that it just stops flying.


It sounds like you're trrying to fly it right down to the ground.. and that's why it wants to keep flying.

The original question:

What should I do to have a normal land with this plane.

Answer:

1) Be at a safe landing weight

2) Establish a stabilized approach well out, so that you're pretty much just waiting on the runway to come to you.

3) Be at Vref, with proper flap deployment on short final.

4) Hold the aircraft just above the ground until the the airspeed falls low enough that it just stops flying.


It sounds like you're trrying to fly it right down to the ground.. and that's why it wants to keep flying.

Brett_H:

Please do, contest away    Discussion is what makes these thing go.

I'm not a jet pilot.. and you point out very important and interesting items. What I do know of small jet piloting, vs small piston piloting, vs BIG jet piloting, comes from talking to other pilots.

While there is no flare (as we'd do it in a C172), there is a transition from approach descent-rate, to the actual landing. You don't want to "plant" a Lear at 500fpm 

That you focused on a target AoA, means that you DO take this seriously. Stabilizing a jet approach AND  nailing an AoA requires a lot of skill  8-)  So you know how important things like landing-weight and approach speed can be.

Every airplane is different. A straight-winged Citation, with relatively low wing-loading, would require more of a "flare" than a high-wing-loaded, swept-wing jet. And a big 737 probably makes the transition from approach vertical speed, to a surviveable "planting" vertical-speed, by ground-effect alone. I really don't know.

I just know that there is a transition.. and if your approach speed is on.. there won't be much floating as you reduce vertical speed (flare, or something resembling a flare) and bleed off ground-speed.

The OP sounds like he's definately coming in fast, and not "flaring"  8-)

Actually, I stopped bothering with the default planes back in the fs2004 days because they simply didn't have the available data available.

That mindset, will get you 75% of the way through a REAL life instrument rating. A good understanding of what's happening and why.. and how nailing numbers makes it all fall into place..  8-)

4) Hold the aircraft just above the ground until the the airspeed falls low enough that it just stops flying.

My understanding it jet aircraft should be flown onto the runway, unlike a Cessna, for example.

[quote]That mindset, will get you 75% of the way through a REAL life instrument rating. A good understanding of what's happening and why.. and how nailing numbers makes it all fall into place..

4) Hold the aircraft just above the ground until the the airspeed falls low enough that it just stops flying.

My understanding it jet aircraft should be flown onto the runway, unlike a Cessna, for example.

That's true, in that it's not a flare-n-stall thing (and varies from jet-to-jet).. but they aren't "flown" to the ground. The same approach practices apply, in that control of airspeed is primarily a pitch thing... and the control of vertical speed is a thrust thing... and the approach speed is critical.

The majority of the final approach will be at negative 500-700fpm; at a VERY specific airspeed. The transition to a vertical speed that won't break things might not get into a stalling airspeed, but it is definately a pitch that will get pretty close.

"Flying" a Lear in at Vref + 30knots will result in the problems the OP described.

Hi guys, I fly the LJ45 constantly, and the 2 key things to landing this jet and pretty much any other jet is speed control and flap settings. i like to do ils approaches, because this helps to keep other functions of the jet under control of the autopilot,and all you have to worry about is adjusting your speed and adjusting your flap settings on the way down.after atc gives me the final heading and runway to use, this is when i drop flaps 1 setting and will,disengage the speed control,as the lj45 doesnt really have an auto throttle persay. once the approach mode takes over and lines me up and begins to descend,this is the time to pay close attention to the speed your at,once you get right on the money with the glide slope,and the descent is correct is when you want to glance over at your speed, if your right on the glideslope but your still at 160, youd better drop the flaps some more, and work the throttles also. the hardest part to learn is controlling the speed with the throttles,as there is a short amount of delay when you push on and off the throttles of a jet, not a delay in the engines but a delay of the movement of the airplane. thats where you have to learn to compensate for that movement,to stay on the glideslope. and the only way to do that is to practice until you get the feeling in your hands. I usually disengage the autopilot around 300 yards out from the threshold, and like to find my self around 125 as i cross the threshold,if you can do that you will be in for a nice soft landing with lots of runway to spare, this is just enough speed to use the control surfaces, and just above the speed at which you are going to stall, i dont get it perfect all the time but when you do and grease this baby in its a great feeling. any way guys just my 2 cents worth.
Take care for now Best regards,Tom

Airspeed is absolutely critical when landing a jet.  I have been told that in some jet aircraft, an extra 5 knots over the threshold will nearly double the distance it takes to get down and stop.