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Landing B737 at low weights

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Landing B737 at low weights

Old 15th Sep 2000, 03:24
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Question Landing B737 at low weights

what is the best way to land this bird with V ref of 125 and low ???? because it just drops on nose wheel as soon as it touches the ground
Old 15th Sep 2000, 14:05
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Aviatorpk - I don’t know your experience so apologies if I pitch this at the wrong level.

A light –500 is tricky because it does run out of elevator at low speed on landing. It was developed from the –300, which is generally heavier and has more moment arm to the stabiliser.

I fly the –500 50% of the time and usually at a landing weight below 45T. My technique is to flare low, buttock clenchingly low if you are used to the –400! A glance at the rad alt shows 16 or less at the start of the manouvere although if your eyes are inside, you are unlikely to get it right. This ensures that the flare will not be too extended which would bleed off the speed causing you to lose elevator effectiveness. At about 16 RA (judged by eye) close the throttles in one quick movement and gently pitch up about 1-2deg. If you only fly the –500 you should get it cracked in weeks, if like me you fly all three then you can still expect to get bitten after 6yrs on type. Some pilots like to add on an extra 5kts if the –500 is light, but personally I think Vref+5 is OK once you have the knack.

Old 15th Sep 2000, 21:25
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On the -200 that we fly I find the best technique to eek out a reasonable landing at light weights is to use Flap 40. This way you can keep on a little more thrust so if a go-around is required the engines are well spooled up. I find at weights below 90,000lbs that the amount of thrust required not to exceed VREF is minimal and I am not comfortable with not having those old JT8D's at too low a power setting.

I have heard that some airlines do not allow the use of Flap 40 under normal operations. At my company however it is approved and is used pretty much every day. We operate into some mountainous strips arond 6000 ft long so when you are heavy and it is wet or slippery Flap 40 becomes a necessity.

This is just what works for me.
Old 15th Sep 2000, 21:53
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have a whole log book of how many times I have thumped it in at light wieghts. Not only does it run out of elevator at slow speed it bounces around all over the place in the lightest of turbulence. The only thing that seems to work (belive me I am no expert) is to take Vref+10 or try Flap 40.
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Old 18th Sep 2000, 05:00
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I don't recall having undue problems with low weight landings and I wouldn't advocate adding extra knots. Having said that, if you have significant Vref additives due headwind component (half the HW component eg 30 knots HWC then add 15 knots to Vref) you might get into a float problem trying to get it on to the ground.
It should be realised that the HWC additives must be gradually reduced on final approach so as to cross the fence at Vref. As the free stream airflow is considered to start at around 2500 feet above ground level, and thus the wind strength gradually reduces due to ground friction below 2500 feet - the Vref additives of HWC (not gust, though) should start to bleed off from say the outer marker height (or equivalent)
There is no way you can bleed off say 15 knots of HWC additive at the flare, to touch down slightly below Vref. Most aircraft will float due non-removed additives and the aircraft may have to be forced on the runway.
Is therefore, your problem with light weight 737 landings, not due to light weight - but perhaps to excess over-the -fence speed above Vref? Just a thought.
Old 18th Sep 2000, 08:06
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For 200 & 300: Just fly with Flap 40 and Vref+10. Flare and land as normal.
If your LW length-limited fly Vref+5 and keep on a tiny trickle of power during the flare. Use the roll-on technique thereafter and cut the power just as you start to nose over.

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