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andreadebiase

landing with flaps 30 or 40?

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How do you exactly pick the flap setting when landing? 

i noticed that most times i can land with flaps 30 where I feel I have more control but i am also faster compare to flaps 40 where i am nice and slow but i also feel like a hovering balloon rather than a plane. If it is windy I prefer less flaps, not more....but all this is how it feels to me....is there a more defined guideline in real life? 

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is there a more defined guideline in real life?

 

Company SOP. In the sim I use 30 unless performance requires 40.

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If you have plenty runway use flaps 30 to save fuel. If you need a lower Vref because of shorter runways or a steeper descent gradient use 40.

 

Company SOP I have heard differs depending on operating environment. At Tegucigalpa Toncontin definitely 40. The downside is more fuel.

 

Challenge yourself to lower the gear at 6 miles out flaps 15 then quicly go to Vref flaps 40 and stabilize the approach 2 miles out.

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If you have plenty runway use flaps 30 to save fuel. If you need a lower Vref because of shorter runways or a steeper descent gradient use 40.

Company SOP I have heard differs depending on operating environment. At Tegucigalpa Toncontin definitely 40. The downside is more fuel.

Challenge yourself to lower the gear at 6 miles out flaps 15 then quicly go to Vref flaps 40 and stabilize the approach 2 miles out.

2 miles out? That's not much distance. You wouldn't even be stable before 1000 ft which most airlines require.

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An other factor to choose flaps 30 is the noise abatement at your destination airport. Flaps 40 requires more thrust, hence more noise, even if it is obviously not a primary concern in  the sim!

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Thank you. All good info.

I usually lower my gear when i intercept the G/S.

This is what i do. As soon as I am 12 miles out I start lowering flaps,  1, 5 and then 10. Depending on wind I may go down to 15 to slow down the plane. As soon as I intercept the G/S I lower landing gear and start lowering more flaps until I get to 30 (or 40). Landing Speed set as per FMC. As soon as runway disappears under my belly disable A/T and cut thrust to zero. Flare and touchdown. Sometimes very smooth sometimes not as smooth as i would like but most times where the two solid lines on the runway are, maybe a little past that. 

Sounds reasonable?

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Flap 30 is the default flap setting for most operators, reduces loads on the flap so they last longer, they provide better noise abatement as you don't need as much thrust which also saves fuel! Flap 40 is used to minimise approach speed thus your landing distance. It's considerably more "draggy" than F30 and you'll typically need 6-10% more N1 to maintain VREF + wind additive on final approach.
 
Our configuration sequence for approach is.

  • F1 no later than 10nm
  • Typically F5 straight after (a 60T 737 will neither decelerate or accelerate on a 3 degree G/P and hold speed nicely) We would use F10 or Speedbrake to reduce speed if needed)
  • In VMC Gear Down/F15 at 4nm. In IMC Gear Down F/15 at 5nm
  • Landing Flap.
  • Stabilised approach criteria is 500ft in VMC, 1000ft in IMC (IMC operator specified as visibility -5km cloud base less than 1000ft)

Hope this helps.

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Hello Andrea,  For easy reference, why not select Init page in FMC when cleaned up and starting cruise, where you will see landing airport runway length, ILS and runway, on left side of page and flaps speed on right side of page. Easy.

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We would use F10 or Speedbrake to reduce speed if needed)

 

I've often wondered if speedbrake use with flaps is acceptable, there are airframes where this is not a good idea.  The speedbrake has the obvious advantage that you can vary the drag where as with F10 once they are down they're not usually coming back up.

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I've often wondered if speedbrake use with flaps is acceptable, there are airframes where this is not a good idea.  The speedbrake has the obvious advantage that you can vary the drag where as with F10 once they are down they're not usually coming back up.

 

The only specific limitations in our flight manual are that you cannot deploy the speed brakes below 1000' RA, and you cannot extend the speed brake lever beyond the flight detent in flight.

 

Extending the speed brakes with the flaps extended more than 10 degrees will give you "SPEED BRAKE EXTENDED" light but it's not prohibited to do so.  Having said that if you need the speed brakes with the flaps at 15 you are in a bad position anyway and should probably consider going around.

 

I often use the speed brakes with the flaps at 5 or 10 degrees, usually if I'm trying to slow down while descending.

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I've often wondered if speedbrake use with flaps is acceptable, there are airframes where this is not a good idea.  The speedbrake has the obvious advantage that you can vary the drag where as with F10 once they are down they're not usually coming back up.

 

Pretty much what Joe said! We're permitted to use speedbrake with up to max Flap 10 and if you select F15 with the speedbrake still extended it will flag up on our monitoring system.  

 

Speedbrake and Flap is a good combo and we try not to use flaps as drag devices, we use flaps to slow down and speedbrake to go down!

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if you select F15 with the speedbrake still extended it will flag up on our monitoring system.

 

And a discussion with a Chief Pilot :Shame On You:

 

Thanks gentlemen, that sure makes it easier to manage the energy.

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hanks gentlemen, that sure makes it easier to manage the energy.

 

Don't underestimate the value of lowering the gear early to help with the energy management.

 

When ORD is landing to the East it's common to have a tailwind down to 1000-2000 AGL combined with a speed reduction to from 210 to 180 knots while you are descending on the glide slope.  It's not at all unusual to drop the gear well outside the FAF while you are still at 3000-4000 AGL.  With a tailwind aloft it's often the only way you can get the airplane to slow down in a timely manner.

 

Another common one is the RNAV visual approach to 28R at SFO.  They sometimes slow you down way out from the runway and keep you high so it's not uncommon to drop the gear at 6000' MSL.

 

The gear in the 737 causes minimal noise and vibration.  It's not a big deal to throw it out early.

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On the 737-800, GOL uses flap 40 because of the higher risk of a tail strike with flaps 30...

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