flap deployment

[[email protected]]

I'd like to get some general information on flap deployment if someone
would be kind enough to provide it.

Is the flap angle normally held constant throughout climb? Ditto for
descent.

If not, what are the typical rules or schedule for changing the flap
angle for a large commercial aircraft? Thanks.

[Capt.Doug]

> wrote in message
> Is the flap angle normally held constant throughout climb? Ditto for
> descent.
> If not, what are the typical rules or schedule for changing the flap
> angle for a large commercial aircraft? Thanks.

The topic can be fairly complicated. Generally speaking, the flaps are
retracted one notch after climbing through somewhere between 800' to 1500'.
The flaps and slats are further retracted as the airplane accelerates.
Climbing with the wing in the 'clean' configuration is most economical.

D.

[tom418[_1_]]

On a B727, flap retraction is done according to a schedule which correlates
flap settings with airspeed.

For example, with a TOGW of 160,000, temp of 59F, and 15 degrees flaps, V2
is 146 knots. Takeoff is done at Flaps 15. Flaps are then retracted to 5
degrees when reaching "V2 + 10" (156 knots), then retracted to 2 degrees
when reaching "V2 + 40" (186 knots), and fully retracted at "V2 + 60" (206
knots).
Note: When 2 degrees of flaps are used, half of the slats get retracted ,
with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
setting
> wrote in message
oups.com...
> I'd like to get some general information on flap deployment if someone
> would be kind enough to provide it.
>
> Is the flap angle normally held constant throughout climb? Ditto for
> descent.
>
> If not, what are the typical rules or schedule for changing the flap
> angle for a large commercial aircraft? Thanks.
>

[Dave Doe]

In article <8hJvg.161350$k%3.95311@dukeread12>,
says...
> On a B727, flap retraction is done according to a schedule which correlates
> flap settings with airspeed.
>
> For example, with a TOGW of 160,000, temp of 59F, and 15 degrees flaps, V2
> is 146 knots. Takeoff is done at Flaps 15. Flaps are then retracted to 5
> degrees when reaching "V2 + 10" (156 knots), then retracted to 2 degrees
> when reaching "V2 + 40" (186 knots), and fully retracted at "V2 + 60" (206
> knots).
> Note: When 2 degrees of flaps are used, half of the slats get retracted ,
> with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
> setting

Surely you also calculate your speeds based on a/c weight? (unlike small
aircraft).

--
Duncan

[John Gaquin]

"Dave Doe" > wrote in message
>>
>> For example, with a TOGW of 160,000, temp of 59F, and 15 degrees flaps,
>> V2
>> is 146 knots. Takeoff is done at Flaps 15. Flaps are then retracted to 5
>> degrees when reaching "V2 + 10" (156 knots), then retracted to 2 degrees
>> when reaching "V2 + 40" (186 knots), and fully retracted at "V2 + 60"
>> (206
>> knots).
>> Note: When 2 degrees of flaps are used, half of the slats get retracted ,
>> with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
>> setting
>
> Surely you also calculate your speeds based on a/c weight? (unlike small
> aircraft).

Note above, he did mention "...TOGW of 160000..."

[tom418[_1_]]

Yes, we do (Take Off Gross Weight = TOGW)

And stop calling me Shirley!
"Dave Doe" > wrote in message
. nz...
> In article <8hJvg.161350$k%3.95311@dukeread12>,
> says...
> > On a B727, flap retraction is done according to a schedule which
correlates
> > flap settings with airspeed.
> >
> > For example, with a TOGW of 160,000, temp of 59F, and 15 degrees flaps,
V2
> > is 146 knots. Takeoff is done at Flaps 15. Flaps are then retracted to 5
> > degrees when reaching "V2 + 10" (156 knots), then retracted to 2 degrees
> > when reaching "V2 + 40" (186 knots), and fully retracted at "V2 + 60"
(206
> > knots).
> > Note: When 2 degrees of flaps are used, half of the slats get retracted
,
> > with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
> > setting
>
> Surely you also calculate your speeds based on a/c weight? (unlike small
> aircraft).
>
> --
> Duncan

[Capt.Doug]

>"tom418" > wrote in message
> Note: When 2 degrees of flaps are used, half of the slats get retracted ,
> with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
> setting

You sure about the Krueger flaps? My library is packed away for remodeling
preventing me from looking it up, but I'm sure only slats 3 &4 are extended
at flaps2, not the Kruegers.

D.

[Morgans[_3_]]

"Capt.Doug" > wrote
>
> You sure about the Krueger flaps? My library is packed away for remodeling
> preventing me from looking it up, but I'm sure only slats 3 &4 are
extended
> at flaps2, not the Kruegers.

Durn it, I was going to let the Krueger flaps go, when he explained it, as
something I really didn't need to know. Now you bring it up again, and now
I want to know! <g>

What the heck are Krueger flaps?
--
Jim in NC

[Jim Macklin]

Flaps the hinge at the bottom from of the leading edge and
swing down to make a more curved section. Slats are
sections of the leading edge that move forward making a
slot.


--
James H. Macklin
ATP,CFI,A&P

"Morgans" > wrote in message
...
|
| "Capt.Doug" > wrote
| >
| > You sure about the Krueger flaps? My library is packed
away for remodeling
| > preventing me from looking it up, but I'm sure only
slats 3 &4 are
| extended
| > at flaps2, not the Kruegers.
|
| Durn it, I was going to let the Krueger flaps go, when he
explained it, as
| something I really didn't need to know. Now you bring it
up again, and now
| I want to know! <g>
|
| What the heck are Krueger flaps?
| --
| Jim in NC
|

[Scott Skylane]

Capt.Doug wrote:
>>"tom418" > wrote in message
>>Note: When 2 degrees of flaps are used, half of the slats get retracted ,
>>with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
>>setting
>
>
> You sure about the Krueger flaps? My library is packed away for remodeling
> preventing me from looking it up, but I'm sure only slats 3 &4 are extended
> at flaps2, not the Kruegers.
>
> D.
>
>
Doug,

Re-read his statement. With flaps 2 selected, leading edge slats 2&3,
and 6&7 are deployed. The remaining slats, as well as *all* krueger
flaps, are retracted.

Happy Flying!
Scott Skylane

[John Gaquin]

"Capt.Doug" > wrote in message news:1UWvg.433226
>
> You sure about the Krueger flaps? My library is packed away for remodeling
> preventing me from looking it up, but I'm sure only slats 3 &4 are
> extended
> at flaps2, not the Kruegers.


Somewhat correct Doug. At Fl 2, only slats 2,3,6,7 extend. At Fl 5,
remaining slats (1,4,5,8) and all LE flaps (1-6) extend. Retract sequence
is reverse.

[tom418[_1_]]

Doug, I had edited my original post, and should have mentioned that the
kruegers get retracted when changing from flaps 5 to flaps 2.

At flaps 2, L.E. Flaps 2,3,6 and 7 are extended, and at 0 flaps, these get
retracted also.

"Capt.Doug" > wrote in message
...
> >"tom418" > wrote in message
> > Note: When 2 degrees of flaps are used, half of the slats get retracted
,
> > with the remaining slats (and the Krueger flaps) retracted with a 0 Flap
> > setting
>
> You sure about the Krueger flaps? My library is packed away for remodeling
> preventing me from looking it up, but I'm sure only slats 3 &4 are
extended
> at flaps2, not the Kruegers.
>
> D.
>
>

[tom418[_1_]]

Correction: At flaps 2, SLATS 2,3,6,7 get retracted.
"tom418" > wrote in message
news:Rq2wg.163322$k%3.21020@dukeread12...
> Doug, I had edited my original post, and should have mentioned that the
> kruegers get retracted when changing from flaps 5 to flaps 2.
>
> At flaps 2, L.E. Flaps 2,3,6 and 7 are extended, and at 0 flaps, these get
> retracted also.
>
> "Capt.Doug" > wrote in message
> ...
> > >"tom418" > wrote in message
> > > Note: When 2 degrees of flaps are used, half of the slats get
retracted
> ,
> > > with the remaining slats (and the Krueger flaps) retracted with a 0
Flap
> > > setting
> >
> > You sure about the Krueger flaps? My library is packed away for
remodeling
> > preventing me from looking it up, but I'm sure only slats 3 &4 are
> extended
> > at flaps2, not the Kruegers.
> >
> > D.
> >
> >
>
>

[Morgans[_3_]]

"Jim Macklin" > wrote in message
news:LbZvg.79434$ZW3.72823@dukeread04...
> Flaps the hinge at the bottom from of the leading edge and
> swing down to make a more curved section. Slats are
> sections of the leading edge that move forward making a
> slot.

Ahaa! I thought they were all slats.
--
Jim in NC

[Capt.Doug]

>"Morgans" wrote in message > Ahaa! I thought they were all slats.

Additionally, on B-727 and B-732, the Krueger flaps will droop down after
the hydraulic pressure is shut off. Turn the hydraulic pumps back on and
they retract quickly. More than one mechanic has been hurt this way.

D.