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OPS1

737NG bugger to land!

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Hello all,

Recently i purchased the ifly 737ng (800/900) I’m usually an 757/767 pilot got lots of hours in the old birds. Anyhow when i come to land and have set my vref speeds etc, it seems to me that the 737 has a relatively high nose pitch up attitude when it’s at its final approach speed (Vref+5kts+cross wind spd) Also i'm finding it a bugger to land especially in the touchdown zone as it always seems to balloon and carry on for several hundreds of metres before smoothly touching down. I'm doing what i usually do in the 757/767's flaring at 20-50ft then knocking the throttles back to idle at 5-15ft. No problem in the 757/767 they seem to just drop down effortlessly. Any idea's or is it just me?

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Try landing with the autopilot and watch how it use the speed and flaps, then do the same. Also make sure that you have set the airport altitude at the correct value- if it is too low,you may float over it. Also make sure that the airport data is correct, so maybe try another airport and see if it does the same.

 

Henri

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The following is the flare technique described in the B737 FCTM:

 

"When the threshold passes under the airplane nose and out of sight, shift the visual sighting point to the far end of the runway. . . . Initiate the flare when the main gear is approximately 20 feet above the runway by increasing pitch attitude approximately 2–3 degrees. . . .

 

After the flare is initiated, smoothly retard the thrust levers to idle, and make small pitch attitude adjustments . . . . Ideally, main gear touchdown should occur simultaneously with thrust levers reaching idle."

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Hello all,

Recently i purchased the ifly 737ng (800/900) I’m usually an 757/767 pilot got lots of hours in the old birds. Anyhow when i come to land and have set my vref speeds etc, it seems to me that the 737 has a relatively high nose pitch up attitude when it’s at its final approach speed (Vref+5kts+cross wind spd) Also i'm finding it a bugger to land especially in the touchdown zone as it always seems to balloon and carry on for several hundreds of metres before smoothly touching down. I'm doing what i usually do in the 757/767's flaring at 20-50ft then knocking the throttles back to idle at 5-15ft. No problem in the 757/767 they seem to just drop down effortlessly. Any idea's or is it just me?

 

It would probably be easier if you had the NGX.. it has an accurate flight model.

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In my opinion, you should be flaring slightly later than you would with the larger aircraft. I find that the wings on the NG, especially when at light weights, are pretty efficient and can easily lead to a float on landing without a solid flare technique.

 

Personally (and I can't speak for the iFly particularly), I try to maintain the approach angle and aircraft attitude until about 40ft. At that point, I'll keep maintain nose attitude, but shift visual reference to the far end of the runway. As the aircraft comes down, I'll probably idle the power at about 25 to 20ft, depending on margin to Vref.

 

As a general rule on the 737, I've learned to calculate Vapp by adding half of any headwind component and all of any additional gust to Vref. Don't be afraid to add an extra couple of knots if you want increased visibility from reduced deck angle during approach, but never allow Vapp to be greater than Vref + 20. Landing with Flaps 40 can also help get the nose down if needed. I stand to be corrected, but I believe the FCOM states that attitude on approach should be between 0 and 3 degrees, which should therefore result in a flare with no greater than 6 degrees nose up.

 

At 20ft, I begin to raise the nose in order to obtain a smooth touchdown. This doesn't require a great deal of elevator input (if I'm correctly configured), but visual reference is crucial here to gauge my vertical speed so that I can adjust the rate at which I bring the nose up, preventing an over- or under-flare. Touchdown should come firmly (to an extent), but should not be hard.

 

The most critical thing, I would say, is power management. I aim to reach Vref at touchdown and so if there is a large margin between Vapp and Vref, I bring back the power a little sooner (30ft?) and let the airspeed bleed. In contrast, if I only have the 5 knot minimum between Vapp and Vref, I'll hang on to it for longer.

 

I think that airspeed makes a big difference to the flare and therefore has a significant effect on the touchdown, and while it's difficult to learn the technique as a whole, the best result will come mainly from experience.

 

I hope this helped you a bit, best of luck!

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Here's my technique. I feel that you can't apply the real world flare procedure for the NGX because it is a tad bit floaty.

 

On approach, use the hud until you can get a feel for this. This technique is for flaps 30. As you approach short final, shift your aim point to 1000ft down the runway(captains bars-2 big blocks). Use the flight path vector to keep your aim point. The 737-800 NGX will approach with a 2.5 degree deck angle at ref+5 about 800fpm. Lock in that picture and continue down keeping stable. At the 30ft call throttle to idle. At the 20ft call, smoothly raise the nose to 4 to 4.5 pitch using the hud. Resist the urge to pitch higher than that target. If you get close to or above the 5 degree ladder, she will float. If you keep 4 to 4.5, the aircraft will fly onto the runway smoothly about 1000 to 1200ft down. You will touch down at vref to ref-5. This technique will get you consistant smooth landings and great landing scores with REX latitude. Fly a couple of pattern only flights to get it down. Before long, you will be able to apply it without the hud.

 

The key is to pitch smoothly to prevent overshooting up and above 5 degrees. Let me know how it works out.

Rich

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I've learned to calculate Vapp by adding half of any headwind component and all of any additional gust to Vref.

Note: With this method, minimum approach speed should still be VREF + 5 kt, regardless of winds.

 

visual reference is crucial here to gauge my vertical speed so that I can adjust the rate at which I bring the nose up, preventing an over- or under-flare.

he most critical thing, I would say, is power management. I aim to reach Vref at touchdown and so if there is a large margin between Vapp and Vref, I bring back the power a little sooner (30ft?) and let the airspeed bleed. In contrast, if I only have the 5 knot minimum between Vapp and Vref, I'll hang on to it for longer.

Good advice! When I sense a premature flare and subsequent flotation, I glance briefly at the radio altimeter to confirm whether I am floating above 4 ft (i.e., whether major corrections are required).

 

Shifting viewpoints alter one's ability to perceive descent rate accurately. Observing the rate at which call outs sound also helps one approximate descent rate and any necessary pitch adjustments.

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I noticed you mentioned you're retarding the throttles at 5-15 feet. That seems a bit late to me. At around 30 feet I retard the throttles and gently begin the flare. The aircraft (NGX in my case) settles onto the runway without much too floating at all. Another common technique is to always anticipate a certain amount of floating, and aim a few hundred feet in front of the intended landing zone on final.

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