Hi, say if for example we planed our fuel incorrectly and we were landing quite heavy.

Would I use flaps 40 to slow my landing down to make it smoother or would I use flaps 30 to lessen (if that's a word) then amount of lift on the aircraft?

 

Or does it depend on the landing weight?

Hey James!

 

Personally I would say yeah use 40 flaps! Just also take into consideration what the length of the Runway that your landing on as you may be able to make it on 30

 

Best Wishes

James Diossy

Hey James!

 

Personally I would say yeah use 40 flaps! Just also take into consideration what the length of the Runway that your landing on as you may be able to make it on 30

 

Best Wishes

James Diossy

Well the runway I'm landing on is 27L at KORD with a size of 2420 m or 7939 ft.

If you are very heavy and landing distance could be a problem, go flaps 40 for less speed at touchdown.

You have got Autobrakes you know??

Use whatever flap setting your performance situation requires.  My personal preference, along with the vast majority of the pilots I fly with, is to land flaps 30 if the situation allows it.  Flaps 40 is recommended if the runway is less than 7000 feet, is wet or you have a tailwind for landing.

 

I landed on 27L at ORD this morning at 142,000 pounds using flaps 30 and easily made the A1 turnoff.

Depends on the airport of landing.

 

A common problem with the -800/-900 is being above the approach & landing climb weight limits on arrival at high altitude airports (e.g. Jackson Hole WY - KJAC).  While landing climb is not a limitation with two-engine aircraft, the approach climb requirement with one engine inoperative can limit the landing weight and/or the flap setting used.  These airplanes may need to use Flaps 30 for dispatch and landing in order to meet the performance requirement.  At KJAC, using flaps 30 and at some of the heavier weights used on landing due to fuel tinkering, these aircraft are bumped into approach CAT E for which there are no landing minimums published.

 

Of course, if you have to use flaps 30 it will increase landing distance and required field length.  It is a balancing act between these two weight requirements. 

 

Rich Boll

Wichita KS

Depends on the airport of landing.

 

A common problem with the -800/-900 is being above the approach & landing climb weight limits on arrival at high altitude airports (e.g. Jackson Hole WY - KJAC).  While landing climb is not a limitation with two-engine aircraft, the approach climb requirement with one engine inoperative can limit the landing weight and/or the flap setting used.  These airplanes may need to use Flaps 30 for dispatch and landing in order to meet the performance requirement.  At KJAC, using flaps 30 and at some of the heavier weights used on landing due to fuel tinkering, these aircraft are bumped into approach CAT E for which there are no landing minimums published.

 

Of course, if you have to use flaps 30 it will increase landing distance and required field length.  It is a balancing act between these two weight requirements. 

 

Rich Boll

Wichita KS

Interesting take. Is this more inline with the BBJ version ? I ask because the airports mentioned and fuel tankering--does not sound like airline operations.

Interesting take. Is this more inline with the BBJ version ? I ask because the airports mentioned and fuel tankering--does not sound like airline operations.

No, it is more an airline issue. Airlines tanker fuel quite often especially where fuel cost are high, like JAC. Surprisingly, I hear that SWA tankers quite a large amount of fuel into the hub at MDW because of its high fuel price.

It's all about performance requirements. If you can land flaps 30, do that. If you can't, due to runway length and condition, go flaps 40. Topcat should help with this.

 

I have always landed with flaps 30 as my first choice. I'll only use flaps 40 if I have to. Why use extra thrust and fuel just to drag an extra flap setting around when it's not needed?

No, it is more an airline issue. Airlines tanker fuel quite often especially where fuel cost are high, like JAC. Surprisingly, I hear that SWA tankers quite a large amount of fuel into the hub at MDW because of its high fuel price.

Thanks good to know !!

The real airplane handles much better on approach and landing with flaps 30 than it does with flaps 40.  There is a lateral shift in the center of lift as the flaps extend beyond 15.  This combined with the roll spoilers makes the airplane less stable in roll with the flaps at 40.  It's easy to get the airplane into a pilot induced oscillation in roll during a full flap approach, especially if its gusty.

 

At my company we can land with the flaps at 15, 30, or 40.  30 is my normal go-to setting.  40 is when the runway is shorter than 7000 feet, or it's wet, or braking action is less than good, or there is a tailwind.  On the really gusty days if the runway is long enough to allow it I will use flaps 15.