Flaps on take-off and landing

Okay, I guess I might as well come clean...

"Jim Logajan" wrote in message
.. .
Are you aware that you are discussing this with one of the programmers
who wrote MS Flight Simulator?

I cross-checked the names of the posters to this thread with the published
MS FS credits I could find and I still don't know who you're talking about
Larry. Unless Bruce Artwick is posting using a non-obvious handle? :-)

Which "published MS FS credits"?

Did you look here (for example)?
http://www.mobygames.com/game/window...r-2000/credits

Now, that said, one of the primary reasons I no longer work for Microsoft is
because of the fiasco surrounding the release of MSFS 2000 and the
remarkably low quality of that product. Frankly, I'm a bit embarassed to be
associated with it at all (though I admit to being happy that my final
contribution before leaving was to fix a particularly egregious performance
bug in the coastline rendering code, so at least after the Christmas patch
that year it didn't quite suck as much as it did when it was released to
manufacturing...and no, the bug I fixed wasn't my fault).

My stint with the MSFS team was a last-ditch effort to recapture the joy I
had had in programming, sucked dry from one bad corporate bureaucratic
experience after another. Suffice to say, it didn't work out (well,
actually I guess it did...I'm much happier now that I code for the pure joy
of it, I just don't work for Microsoft anymore ).

Anyway, that's a long way of saying I don't generally like to bring up my
involvement with MSFS. IMHO, the product released makes me look bad by
association.

Pete

"Mxsmanic" wrote in message
...
Why do large commercial jets seem to have huge flaps with many
settings, whereas small planes have tiny flaps with one or two
settings, or none at all?

Flaps enhance lift at the expense of drag. On a small airplane, large
complex flaps would not produce a significant enough reduction in drag
during cruise flight to justify the cost, complexity, and weight.

However, the larger and faster the airplane, the more there can be
accomplished by reducing drag significantly during cruise, especially
compared to the airfoil required to land such planes safely and within the
runways available to them (generally no longer than a couple of miles or
so).

You could land a 747 without flaps, but you'd use a LOT more pavement (maybe
double?), runway length that just isn't available. On the other hand, you
could design a 747 with an airfoil that allowed for shorter landings, but
cruise speed would suffer. The airplane is large enough and fast enough
that the extra expense and weight of flaps more than makes up for its cost
during cruise, while still allowing for reasonable landing performance.

Hopefully this one example has answered the general question of "why do
large airplanes have features not found on small airplanes?" You could
spend months asking that same question, using different features, and the
answer would always be the same: economics and usefulness.

Pete

"Peter Duniho" wrote:
Which "published MS FS credits"?

I have version 6 and the 2004 version, so I tried to check their credits.

Did you look here (for example)?
http://www.mobygames.com/game/window...mulator-2000/c
redits

Nope - didn't see that. Looks like I overlooked the version(s) you worked
on.

My stint with the MSFS team was a last-ditch effort to recapture the
joy I had had in programming, sucked dry from one bad corporate
bureaucratic experience after another.

That's appears to be a common problem. :-(

Google for "Custer channel wing" to see what extreme effect
prop wash can have.



"Peter Duniho" wrote in
message ...
| "Mxsmanic" wrote in message
| ...
| [...]
| 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.
|
| In addition to what's already been written, it's not true
that "the airflow
| from the prop should stay in roughly the same place".
Aircraft attitude
| affects relative wind, which in turn affects where the
airflow from the prop
| goes. This is a significant effect. As well, aircraft
attitude affects up-
| and down-wash from aerodynamic surfaces which also affects
where the airflow
| from the prop goes.
|
| Air moving back from the prop doesn't do so independently
of all the other
| air around the airplane. It mixes with, interacts with,
is affected by, and
| otherwise reacts to all the other air in response to
everything else that is
| going on.
|
| That is, it would be like putting a big fan on a
| sailboat to drive it forward.
|
| Depends. If you put the big fan at the front of the
sailboat and direct it
| rearward, you can not only propel the sailboat, if you put
a sail in the
| flow you can redirect the flow to accomplish different
things (though why
| you'd bother on a sailboat, I don't know).
|
| Likewise, in an airplane you can redirect thrust to
provide aerodynamic
| control. There is a very minimal reduction in the thrust
(as the
| redirection creates some drag, offsetting the thrust)
while the control
| surfaces get more air to work with. You are right to
think that you don't
| get something for nothing, but in this particular
situation, the cost (in
| drag) is insignificant compared to the improvement in
control effectiveness
| (from redirecting the prop thrust).
|
| As an extreme example, consider the airshow pilot who can
change the pitch
| attitude of his tailwheel airplane on the ground by
locking the brakes and
| using engine power and elevator control to raise or lower
the tail as he
| desires. The fact that the engine and prop are attached
to the airframe in
| no way prevents the thrust from the prop from being used
by the elevator to
| effect a pitch change.
|
| Pete
|
|

Skylune wrote:
The sim is better than real life. I've done both. In the little planes,
when u need to urinate, you do it in your pants or into a container. As
for the other bodily functions, you just gotta hold it and hope that there
isn't alot of traffic ahead of you before its your turn to land. (And the
pilots wonder why more women don't want to deal with this).

Or you could just land at the next airport. It's just like waiting for
the next freeway exit.

In the little planes, you are oftentimes dealing with 1960s technology.
The little planes are either too hot or too cold. They can't get you
where you want to go unless you have an IFR license and a capable plane.
In the little planes, you have to worry about other marginally trained
pilots running into you (either on the ground, mid-air, or in the traffic
pattern).

Never had someone hit me in a plane, in the car is another story. We
fly VFR rather frequently and get where we are going and back.

In the little planes, you will waste at least $100K between the training,
equipment, insurance, gas, etc. (Better off buying a really nice BMW or
Audi or Porsche, which will get you where you want in less time, and where
you can pull over at a rest stop when you want).

On trips shorter than 100 miles I can beat the plane with the Audi.
Longer trips the plane does much better. I also don't risk getting a
speeding ticket with the Navion.

And, best of all, in the sim world you can fly into and out of Megis Field
to your heart's content!


All without leaving your living room :-(

Margy

On Fri, 15 Sep 2006 17:16:10 -0000, Jim Logajan
wrote in :

Larry Dighera wrote:
Mxsmanic wrote:
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.

Are you aware that you are discussing this with one of the programmers
who wrote MS Flight Simulator?

I cross-checked the names of the posters to this thread with the published
MS FS credits I could find and I still don't know who you're talking about
Larry. Unless Bruce Artwick is posting using a non-obvious handle? :-)


If you go back through the message thread, you'll see who Mxsmanic was
discussing with at the time I posted the follow-up article..

On Fri, 15 Sep 2006 17:04:42 -0400, Margy Natalie
wrote in :

I also don't risk getting a speeding ticket with the Navion.

That is a significant benefit on Interstate 5 along the California
coast.

The California Highway Patrol runs an aerial speed trap between Paso
Robles and San Luis Obispo. The solo officer (Marlin Verin*) piloting
the C-206 issued ten citations in an hour and forty-five minutes (1
every 10.5 minutes average) on June 8th. He does this by matching his
ground speed to the vehicle he's pacing, and then clocking his time
through a measured mile on the ground. But speed traps, and any
evidence obtained through their use, are specifically prohibited by
several sections of the CVC.**

San Luis Obispo County is sparsely populated (by comparison to LA or
SF), so in order to defend yourself, you have to make long road trips
to the courthouse from the county in which you reside. It's not
difficult to win an acquittal, but the inconvenience is a poppa india
tango alpha.



* http://www.geocities.com/eaa170/nl/O...Newsletter.pdf

** http://www.dmv.ca.gov/pubs/vctop/vc/tocd17c3a1.htm

But speed traps, and any
evidence obtained through their use, are specifically prohibited by
several sections of the CVC.**

** http://www.dmv.ca.gov/pubs/vctop/vc/tocd17c3a1.htm

Speed traps are not defined. How well can they argue that a speed trap
isn't one?

Jose
--
There are more ways to skin a cat than there are cats.
for Email, make the obvious change in the address.

Larry Dighera wrote:

He does this by matching his
ground speed to the vehicle he's pacing, and then clocking his time
through a measured mile on the ground.


What's the point of matching his speed? Just time the car with the
stripes painted on the road.

On Fri, 15 Sep 2006 18:05:14 -0600, Newps wrote
in :


Larry Dighera wrote:

He does this by matching his
ground speed to the vehicle he's pacing, and then clocking his time
through a measured mile on the ground.


What's the point of matching his speed? Just time the car with the
stripes painted on the road.

You didn't read the information at the link to the California Vehicle
Code that I provided. It defines a speed trap as what you suggest,
and they have been prohibited since early last century.


http://www.dmv.ca.gov/pubs/vctop/d17/vc40802.htm
40802. (a) A "speed trap" is either of the following:

(1) A particular section of a highway measured as to distance and
with boundaries marked, designated, or otherwise determined in
order that the speed of a vehicle may be calculated by securing
the time it takes the vehicle to travel the known distance.



The elements of this section a

1. A measured section of highway
2. Timing a vehicle over the measured course
3. Calculating the speed from the time over the measured distance

Timing the aircraft is an attempt to circumvent the law, as pacing
automobiles on the road has been done as long as I can remember. But,
an aircraft is also a vehicle, and the other elements are met, so any
rational person can see that the CHP is running a speed trap.

But the magistrate isn't about to set a legal precedent by agreeing
with that argument, however there is a section of evidentiary code
that requires the prosecution to guarantee that a preponderance of the
evidence (testimony in this case) assures that the arresting officer
was able to positively identify the vehicle he is tracking by having
it in sight at all times. If the aerial officer is unable to identify
the driver from 1,000' above, determine the make of automobile, nor
read the licence plate number, and he has to look at his stopwatch and
flight instruments and scan for traffic, the prosecution will fail
that requirement.