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Driver170

flap maneuvering speed and minimum maneuvering speed

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Lets say Flaps 5 takeoff, you retract from F5 to F1 at V2 + 15 the white bug and accelarating. Now you'll be under F1 manoevering speed (1) green bug. Will the AC now be limited to 30* of bank? 15+15 for overshoot?

 

Not really a big deal in this scenario. Most planes, atleast the ones I flew, are limited to 15 degrees bank when below min maneuver speed for configuration. For example, in the DC10, this was a normal occurance during clean up. Before take off, there was a decision to be made. If you needed more than 15 degrees of bank during the takeoff(SID), you accel to flap retract speed, stay configured and clean up after the turn. If you didn't need more than 15 degrees bank, clean up on schedule. I did like that the DC10 gave you a min maneuver for each configuration. I hate doing math during takeoff.

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If you needed more than 15 degrees of bank during the takeoff(SID), you accel to flap retract speed, stay configured and clean up after the turn. If you didn't need more than 15 degrees bank, clean up on schedule.

 

Is this the same for the 737 then?

Also after takeoff why do pilots set flaps up speed if not arming VNAV on the ground?


Vernon Howells

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The AOA indicator is your friend.  Keep it at three o'clock or greater and all will be well.

 

Billy Bluestar


I Earned My Spurs in Vietnam

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The AOA indicator is your friend.  Keep it at three o'clock or greater and all will be well.

 

Billy Bluestar

That's a very "Navy" way of flying. I don't have an AOA in my right seat RW, so I rely on the speed schedules from the FCTM. I think the AOA may give a great advantage but disagree with Boeing's recommendations.


Matt Cee

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the AOA may give a great advantage but disagree with Boeing's recommendations

One of my compadres has been flying the -800 for about ten years and thinks Boeing got it right. :-)

 

Billy Bluestar


I Earned My Spurs in Vietnam

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One of my compadres has been flying the -800 for about ten years and thinks Boeing got it right. :-)

 

Billy Bluestar

 

I've flown (trained) from the left seat for maybe 10-20 hours, and never got much into the HUD and the AOA. Oddly no one at my airline mentions it - probably because it's only on the left side.

 

3 o'clock is a good place to be, from what I've just read, so I'll go with what you and your friend says.

 

We almost exclusively fly the Ref+additive speeds from what I see. It's probably a little less efficient.


Matt Cee

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Is this the same for the 737 then?

Also after takeoff why do pilots set flaps up speed if not arming VNAV on the ground?

 

 

I would think so, but i know the boeings clean up differently than what i'm used to. In the DC10/MD11, at flap retract speed, you fully retract flaps up to slats extended. At slat retract, you suck up slats for a clean wing. Every time you suck up flaps and slats, you are momentarily below min maneuver. In the boeings, it seems they retract flaps in stages. Atleast they have the speeds on the speed tape.

 

As far as setting flaps up speed, its interesting. In the DC10/MD11, V2 is in the window until clean up. In the DC10, you state "flaps up,bug me up" At flap retract speed. The pilot monitoring will retract flaps and set 250/min manuever which ever highest. In the MD11, thats happens automatically when in FMS mode. In the G5/550, The speed will go from V2 automatically to 200(terminal area speed), as soon as the flap handle is placed to flaps up position. After leaving terminal area, it switches to 250. This works a little differently in the 737. I believe that the speed will flag for flap overspeed protection if you set a speed above flap placard speeds when still configured. This is probably why they set flaps up speed. Spin may have better info.

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Is this the same for the 737 then?

Also after takeoff why do pilots set flaps up speed if not arming VNAV on the ground?

 

You don't have to arm VNAV on the ground. You can also select VNAV at acceleration height, e. g. 800' or whatever your operator wants. No need to set up speed if you don't want to.

 

sig.gif

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I know with the new software U10.8 you can arm VNAV on the ground as this now provides overspeed protection for the LE flaps 230kts.

 

But of course SOPs

 

I'll engage VNAV at 3000 feet.


Vernon Howells

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FCTM 3.29

 

If VNAV is not used, at acceleration height set the command speed to flaps up maneuver speed.

Or is this down to SOPs?


Vernon Howells

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I know with the new software U10.8 you can arm VNAV on the ground as this now provides overspeed protection for the LE flaps 230kts.

 

But of course SOPs

 

I'll engage VNAV at 3000 feet.

 

Yes, of course it does, but it does the same in flight when you select it at acceleration altitude. The protection is also modelled in the NGX. However under certain conditions it's not recommended to have it armed on ground due to a software anomaly (check this for further information).

 

FCTM 3.29

 

If VNAV is not used, at acceleration height set the command speed to flaps up maneuver speed.

Or is this down to SOPs?

 

As said above, it you opt to not use VNAV, then you set up speed at acceleration altitude.

 

sig.gif

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rse it does, but it does the same in flight when you select it at acceleration altitude. The protection is also modelled in the NGX. However under certain conditions it's not recommended to have it armed on ground due to a software anomaly (check this for further information).

 

So its all down to mainly windshear if in the area!?

As said above, it you opt to not use VNAV, then you set up speed at acceleration altitude.

 

Is this to protect LE flaps and also to manage tight turns?


Vernon Howells

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Thats when you retract from Flaps 5 to Flaps 1

Minimum of V2+15 and accelerating gets a Flaps 1 call from me. SOP.

 

Sorry guys, my mistake. I'm not a "procedural" simmer so never studied an SOP. My technique for flap retraction is to wait till the speed trend vector is close to the next flap manoeuvre speed then retract to that detent. I'm fairly sure I read that in the forum. That's why a 5 knot speed increase didn't seem enough to me to justify a flap retraction. I didn't realise Vernon was quoting from the SOP.

 

You live and learn. I'll try the correct procedure next time I fly the NGX.


ki9cAAb.jpg

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Sorry guys, my mistake. I'm not a "procedural" simmer so never studied an SOP. My technique for flap retraction is to wait till the speed trend vector is close to the next flap manoeuvre speed then retract to that detent. I'm fairly sure I read that in the forum. That's why a 5 knot speed increase didn't seem enough to me to justify a flap retraction. I didn't realise Vernon was quoting from the SOP.

 

You live and learn. I'll try the correct procedure next time I fly the NGX.

It is a bit counter-intuitive. At lease you were erring on the cautious side. :)


Matt Cee

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I didn't realise Vernon was quoting from the SOP.

 

Hi kevin! Its not an SOP, its in the FCTM. I'll quote it...


Vernon Howells

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