Flaps on take-off and landing

Mxsmanic wrote:
Are there full-motions simulators for specific GA aircraft, such as
the Baron 58 that I've mentioned?

Consider making or buying your own.

Google for the keywords "full" "motion" "simulator" - you'll come up with a
bunch of relevant hits. Here's some:

Plans for allegedly building your own for under $350:
http://www.acesim.com/main.html

Another do-it-yourself set of plans:
http://www.simcraft.com/phpPages/products/primusDIY.php

Some vendors, no price info:

http://www.noonco.com/flyer/
http://www.flightmotion.com/home.htm
http://home.claranet.nl/users/wvdlel...h/index-e.html

In article SwnOg.22694$SZ3.9372@dukeread04,
"Jim Macklin" wrote:

Every airplane with flaps has speed limits with flaps
extended. If there is a positive stop, they may have a
series of allowable speeds.

Why do you say "positive stop"? I think you're talking about:

*23.1511***Flap extended speed.

(a) The flap extended speed VFE must be established so that it is‹

(1) Not less than the minimum value of VF allowed in 23.345(b); and

(2) Not more than VF established under 23.345(a), (c), and (d).

(b) Additional combinations of flap setting, airspeed, and engine power
may be established if the structure has been proven for the corresponding
design conditions.

I don't see anything there that mandates a "positive stop".

The application of the rule has required a positive detent
to limit the flap position.



"Roy Smith" wrote in message
...
| In article SwnOg.22694$SZ3.9372@dukeread04,
| "Jim Macklin"
wrote:
|
| Every airplane with flaps has speed limits with flaps
| extended. If there is a positive stop, they may have a
| series of allowable speeds.
|
| Why do you say "positive stop"? I think you're talking
about:
|
| 23.1511 Flap extended speed.
|
| (a) The flap extended speed VFE must be established so
that it is
|
| (1) Not less than the minimum value of VF allowed in
23.345(b); and
|
| (2) Not more than VF established under 23.345(a), (c), and
(d).
|
| (b) Additional combinations of flap setting, airspeed, and
engine power
| may be established if the structure has been proven for
the corresponding
| design conditions.
|
| I don't see anything there that mandates a "positive
stop".

"Jim Macklin" wrote in message
news:_ipOg.22703$SZ3.21706@dukeread04...
The application of the rule has required a positive detent
to limit the flap position.



Could you elaborate on that, please?

"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

Tom Young writes:

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.

In simulation it seems that flying slow with flaps extended makes the
aircraft more prone to exaggerated movement for a specific control
input, especially in larger aircraft. Is an aircraft inherently less
stable at slow speeds with flaps extended? If so, is it just because
the flaps are out, or is it the slow speed that does it?

When flying around a city for fun at low altitudes (2000-3000 feet), I
often fly with full flaps and throttles near idle. It makes it easier
to go slow and enjoy the view, but I also get the impression that the
envelope of safe maneuvering is smaller in this configuration. But I
don't know if it's the flaps that do that, or the slow speed, or
perhaps both.

When I first tried simulation (many years ago now), I was surprised by
the drag effect of flaps. I had read about it but I didn't realize it
was so significant. I finally understood why I had heard commercial
pilots increasing engine speed while approaching a runway on landing.
I find myself doing the same thing, to maintain altitude mainly, and
also because it seems to improve flight characteristics if one flies
with more power (?), as opposed to just gliding in at the slowest
possible speed.

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"Mxsmanic" ... wrote in message
...
In simulation it seems that flying slow with flaps extended makes the
aircraft more prone to exaggerated movement for a specific control
input, especially in larger aircraft. Is an aircraft inherently less
stable at slow speeds with flaps extended? If so, is it just because
the flaps are out, or is it the slow speed that does it?

Hm... Slow flight is accompanied by soft-feeling controls and less control
authority (i.e. you have to put in more input to get the aircraft to
respond, not less). By the same token, you have to put in more control to
stop the plane from rolling (or whatever) once started, so that might be
what is giving you that impression. Dunno.

When flying around a city for fun at low altitudes (2000-3000 feet), I
often fly with full flaps and throttles near idle. It makes it easier
to go slow and enjoy the view, but I also get the impression that the
envelope of safe maneuvering is smaller in this configuration. But I
don't know if it's the flaps that do that, or the slow speed, or
perhaps both.

I'm not quite sure what you mean by 'envelope of safe maneuvering.' You
can't go as fast with flaps extended, because something might break, but you
can fly slower, because of the additional lift.

When I first tried simulation (many years ago now), I was surprised by
the drag effect of flaps. I had read about it but I didn't realize it
was so significant. I finally understood why I had heard commercial
pilots increasing engine speed while approaching a runway on landing.
I find myself doing the same thing, to maintain altitude mainly, and
also because it seems to improve flight characteristics if one flies
with more power (?), as opposed to just gliding in at the slowest
possible speed.

I'll have to take your word for it -- I've never flown a big airplane, real
or simulated. In smaller airplanes where the propwash flows over the control
surfaces, your elevator and rudder are more responsive at higher RPMs.

Tom Young

Tom Young writes:

Hm... Slow flight is accompanied by soft-feeling controls and less control
authority (i.e. you have to put in more input to get the aircraft to
respond, not less). By the same token, you have to put in more control to
stop the plane from rolling (or whatever) once started, so that might be
what is giving you that impression. Dunno.

That sounds like it. I just described it poorly. It feels mushy.

I'm not quite sure what you mean by 'envelope of safe maneuvering.' You
can't go as fast with flaps extended, because something might break, but you
can fly slower, because of the additional lift.

By envelope I mean the area of safety between two extremes, e.g., the
"coffin corner" of some aircraft represents a very tiny envelope,
since more than a slight movement in any direction may result in
irrecoverable instability.

I'll have to take your word for it -- I've never flown a big airplane, real
or simulated. In smaller airplanes where the propwash flows over the control
surfaces, your elevator and rudder are more responsive at higher RPMs.

I'm surprised that propwash would matter, since the airflow from the
prop should stay in roughly the same place no matter what the attitude
of the aircraft. That is, it would be like putting a big fan on a
sailboat to drive it forward.

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On Fri, 15 Sep 2006 02:16:58 +0200, Mxsmanic
wrote in :

Sometimes if one must
descend rapidly just idling the throttle doesn't seem to be enough to
stay below hazardous speeds,

In those situations, you can descend by flying slowly (slower than Vx)
on the other side of the knee in the curve, but you must remain above
stall speed.

In those situations, you can descend by flying slowly (slower than Vx)
on the other side of the knee in the curve, but you must remain above
stall speed.

Try it at altitude first so you get a feel for the impending stall
should it occur. I did this to a landing once in a spot landing contest
where we were not allowed to slip, and I was high. Scared my passenger
(also a pilot) though; apparantly he hadn't really done much full-stall
slow flight.

Jose
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