Flaps on take-off and landing

At what point does one normally set flaps before take-off? I've been
doing it only when aligning with the runway, on the theory that
extending flaps prior to that would just make me more vulnerable to
wind while on the taxiway or at the gate. Similarly, I retract the
flaps completely as soon as I'm completely on the runway for landing,
so that the wind doesn't push me around. Is this the correct way to
do it?

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I generally extend flaps as I approach the holding point, stops the wind
grabbing you and better visibility all round (well for the Cessna)

As for retracting, I use them for a drag advantage to slow the aircraft
down and retract when I have full nosewheel steering control of the
aircraft!

This is real world, as for simulator.. just throw them down during the
taxy! Generally, airline drivers have flaps set prior to taxy after
pushback!


Jad


Mxsmanic wrote:
At what point does one normally set flaps before take-off? I've been
doing it only when aligning with the runway, on the theory that
extending flaps prior to that would just make me more vulnerable to
wind while on the taxiway or at the gate. Similarly, I retract the
flaps completely as soon as I'm completely on the runway for landing,
so that the wind doesn't push me around. Is this the correct way to
do it?

"Mxsmanic" wrote in message
...
At what point does one normally set flaps before take-off? I've been
doing it only when aligning with the runway, on the theory that
extending flaps prior to that would just make me more vulnerable to
wind while on the taxiway or at the gate. Similarly, I retract the
flaps completely as soon as I'm completely on the runway for landing,
so that the wind doesn't push me around. Is this the correct way to
do it?

It depends on the airplane and the pilot.

Personally, for the airplane I am flying the most, I have the flaps down
from preflight to takeoff. This is because the airplane requires flaps for
landings and takeoffs, there is only one "flaps down" setting, and I like
having the flaps down during the preflight as well. So I put the flaps down
before a landing, and they don't come up until after the next takeoff.

For Cessnas, which generally don't require flaps for takeoff, it's a
different matter. I lower the flaps for the preflight inspection so that I
can properly inspect the flap mechanisms, but then retract them after engine
start and before taxiing. Certain takeoffs may dictate lowering them again
prior to takeoff, which I do as part of my pre-takeoff checks, which include
reviewing the takeoff procedure checklist (flap setting is listed with the
checklist items for the takeoff itself).

Some pilots retract the flaps as soon as they touchdown, with the theory
that this will enhance their braking. However, IMHO this ignores the fact
that there is more aerodynamic braking with the flaps down early in the roll
out, and by the time the extra drag is negligible, so is any additional lift
the flaps might be generating. It also ignores the hazard in some airplanes
of accidently retracting the landing gear rather than the flaps.

Other airplanes run the gamut in terms of what's required or desired
operationally, and of course each pilot may have their own preferences as
well.

IMHO, since you're not actually flying an airplane, I wouldn't worry about
it. Put the flaps down whenever you want.

Pete

Peter Duniho writes:

I lower the flaps for the preflight inspection so that I
can properly inspect the flap mechanisms, but then retract them after engine
start and before taxiing.

Doesn't flap movement require engine power?

IMHO, since you're not actually flying an airplane, I wouldn't worry about
it. Put the flaps down whenever you want.

The idea is to try to approach real life. Additionally, many things
are simulated. If adjusting flaps has a bad effect in real life,
there's a good chance that it has a bad effect in simulation as well.

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Some airplanes use electric motors to move the flaps, some
use engine driven hydraulic pumps. Some use hand cranks and
some use a lever.

Most light aircraft use either a mechanical human powered
lever or crank or electric motors that will run on the
battery. Heavier airplanes, over 12,000 pounds often use
hydraulics. Sometimes the hydraulic pumps are electric
powered, but engine driven pumps are common.


"Mxsmanic" wrote in message
...
| Peter Duniho writes:
|
| I lower the flaps for the preflight inspection so that I
| can properly inspect the flap mechanisms, but then
retract them after engine
| start and before taxiing.
|
| Doesn't flap movement require engine power?
|
| IMHO, since you're not actually flying an airplane, I
wouldn't worry about
| it. Put the flaps down whenever you want.
|
| The idea is to try to approach real life. Additionally,
many things
| are simulated. If adjusting flaps has a bad effect in
real life,
| there's a good chance that it has a bad effect in
simulation as well.
|
| --
| Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic wrote:
Peter Duniho writes:

I lower the flaps for the preflight inspection so that I
can properly inspect the flap mechanisms, but then retract them after engine
start and before taxiing.

Doesn't flap movement require engine power?

Depends on the aircraft. Some planes they are purely mechanical from
the flap handle in the cockpit. In others they are electric. On my
plane they are hydraulic, which is run from the engine if it is running
but has a backup "wobble pump" which I can use to retract them on the
ground if I forget to do so before shutdown.

My plane specs flaps up or 1/2 for takeoff (short field takeoff done
with 1/2). Landing can be done with any setting of flaps.

Ron Natalie writes:

Depends on the aircraft. Some planes they are purely mechanical from
the flap handle in the cockpit.

I'm surprised that a small handle in the cockpit would provide enough
leverage to lower flaps. Isn't there are a lot of aerodynamic
pressure to overcome against them (at least if they are lowered in
flight)?

I'm always surprised by how much is still mechanically linked in
aircraft. I'm not necessarily saying that's bad--simple is reliable,
generally speaking--but somehow I don't picture control surfaces as
something that one could easily move without assistance. I suppose
small planes are lighter than they appear, and just because the wings
look relatively big doesn't mean that they are heavy or hard to move.

My plane specs flaps up or 1/2 for takeoff (short field takeoff done
with 1/2). Landing can be done with any setting of flaps.

I've always been landing with flaps down completely, and usually
taking off with some flaps, as I had read that this was necessary (and
I had seen accident reports about pilots who crashed because they took
off without first lowering flaps). But from what you and others here
say it sounds like I have considerably more discretion in whether or
not I lower flaps for both operations.

Are there good reasons to lower flaps in flight, outside take-off and
landing? I've thought that they would be useful for increasing drag
and lowering airspeed, but since they apparently cannot be used at
high speeds I guess this isn't a good idea. Sometimes if one must
descend rapidly just idling the throttle doesn't seem to be enough to
stay below hazardous speeds, and few aircraft seem to have speed
brakes.

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Mxsmanic wrote:
Ron Natalie writes:


Depends on the aircraft. Some planes they are purely mechanical from
the flap handle in the cockpit.


I'm surprised that a small handle in the cockpit would provide enough
leverage to lower flaps.

Who said the handle is small? Some of these "handles" are 2 - 3 feet long.

Margy
Isn't there are a lot of aerodynamic
pressure to overcome against them (at least if they are lowered in
flight)?

Every airplane with flaps has speed limits with flaps
extended. If there is a positive stop, they may have a
series of allowable speeds. The same sort of limits apply
to landing gear extension and operation with the gear
extended.

In some airplanes the gear is not to be extended at speeds
above a certain speed because the motor and linkage is not
strong enough, but once fully extended and lock down, the
airplane can be flown at a higher speed. Some airplanes can
have the gear extended at very high speed in an emergency,
but then the gear doors may be damaged and require
replacement or adjustment before the next flight.

Real airplanes and the simulators that exactly duplicate a
particular airplane are flown by the identical procedures.
Table-top PC "simulators" are more properly known as
training devices and they mimic some generic airplanes.

A real simulator costs more than the airplane it is
duplicating, a Beechjet or Boeing simulator can cost $8-10
million dollars or more. It is worthwhile because it
doesn't burn several thousand pounds of fuel per hour, can
be run nearly 24/7, rarely kills anyone and it is a safe
place to do things that can't be done safely in a real
airplane. Also, it allows the airplane to be out earning
revenue.

Even a PC based training device is very useful for learning
and practicing procedures, but you get what you pay for. A
King Air trainer with out full visual and motion still
allows learning all the systems and practicing the various
emergency and abnormal procedures.



"Mxsmanic" wrote in message
...
| Ron Natalie writes:
|
| Depends on the aircraft. Some planes they are purely
mechanical from
| the flap handle in the cockpit.
|
| I'm surprised that a small handle in the cockpit would
provide enough
| leverage to lower flaps. Isn't there are a lot of
aerodynamic
| pressure to overcome against them (at least if they are
lowered in
| flight)?
|
| I'm always surprised by how much is still mechanically
linked in
| aircraft. I'm not necessarily saying that's bad--simple
is reliable,
| generally speaking--but somehow I don't picture control
surfaces as
| something that one could easily move without assistance.
I suppose
| small planes are lighter than they appear, and just
because the wings
| look relatively big doesn't mean that they are heavy or
hard to move.
|
| My plane specs flaps up or 1/2 for takeoff (short field
takeoff done
| with 1/2). Landing can be done with any setting of
flaps.
|
| I've always been landing with flaps down completely, and
usually
| taking off with some flaps, as I had read that this was
necessary (and
| I had seen accident reports about pilots who crashed
because they took
| off without first lowering flaps). But from what you and
others here
| say it sounds like I have considerably more discretion in
whether or
| not I lower flaps for both operations.
|
| Are there good reasons to lower flaps in flight, outside
take-off and
| landing? I've thought that they would be useful for
increasing drag
| and lowering airspeed, but since they apparently cannot be
used at
| high speeds I guess this isn't a good idea. Sometimes if
one must
| descend rapidly just idling the throttle doesn't seem to
be enough to
| stay below hazardous speeds, and few aircraft seem to have
speed
| brakes.
|
| --
| Transpose mxsmanic and gmail to reach me by e-mail.

"Mxsmanic" ... wrote in message
...
I'm surprised that a small handle in the cockpit would provide enough
leverage to lower flaps. Isn't there are a lot of aerodynamic
pressure to overcome against them (at least if they are lowered in
flight)?

In a Beech Sundowner the handle is maybe 18" long and looks like a big
version of a parking brake lever that you might see in a car. There's more
resistance the higher your airspeed, but it pulls up easily enough below the
max flaps speed. Also, it's good to have a bit of mechanical feedback like
that in case you don't have your wits about you and try to pull flaps at too
high an airspeed.

Are there good reasons to lower flaps in flight, outside take-off and
landing? I've thought that they would be useful for increasing drag
and lowering airspeed, but since they apparently cannot be used at
high speeds I guess this isn't a good idea. Sometimes if one must
descend rapidly just idling the throttle doesn't seem to be enough to
stay below hazardous speeds, and few aircraft seem to have speed
brakes.

Flaps have two main effects, they increase drag, like you said, and they
also increase lift and reduce your stall speed. These two effects can be
useful at different times. For example, if your wing is on fire and you want
to descend quickly, you lower the flaps and descend at Vfe (max speed with
flaps extended, top of the white arc). It's an interesting exercise the
first time you practice it, with the ground filling up your windscreen like
that and all. Another use is when you simply want to fly slower, such as
when you're in the traffic pattern and want to avoid getting too close to
someone in front of you. You can slow down without flaps, but using them
keeps you farther from a stall, which is a good thing at pattern altitude.
I'm sure more experienced pilots can give more interesting ways to use flaps
in normal flight, but those are the ones that come to mind just now.

Tom Young