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Home > Archive > Flight simulator > March 2006 > take-off roll "jump"
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take-off roll "jump"
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| A question for the real world pilots. I know in FS 2004 when in the take-off
roll in the C172, pulling back smoothly on the yoke makes the aircraft
literally jump into the air and then I must correct with forward pressure.
Does this happen in a real C172?
Mike
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| Beech45Whiskey 2006-03-09, 7:33 pm |
| Mike <nospam@comcast.net> wrote:
quote:
> I know in FS 2004 when in the take-off
> roll in the C172, pulling back smoothly on the yoke makes the aircraft
> literally jump into the air and then I must correct with forward pressure.
> Does this happen in a real C172?
No, smooth backward pressure on the yoke when the C172SP reaches 55kts
results in a gentle lift off.
It is only when a strong wind gust hits at that moment, or a quick, hard
yank on the yoke at speeds greater than 65kts or so will the C172SP "jump"
off the runway.
--
Peter
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| Dudley Henriques 2006-03-09, 7:33 pm |
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"Mike" <nospam@comcast.net> wrote in message
news:e4ydnQJtWNqkz43ZnZ2dnUVZ_tGdnZ2d@comcast.com...
quote:
>A question for the real world pilots. I know in FS 2004 when in the
>take-off roll in the C172, pulling back smoothly on the yoke makes the
>aircraft literally jump into the air and then I must correct with forward
>pressure. Does this happen in a real C172?
>
> Mike
No. Control use in the real airplane...any real airplane....should always be
considered as pressure vs result. This equates to a smooth application of
control pressures to achieve a specific result and "adjusting" the applied
pressures constantly as you are flying the airplane.
It's common among sim pilots to overcontrol the airplane because of the
ratio between the controller pots and the on screen visual result of
movement of those pots. Because the element of "feel" is missing from the
pressure equation, the natural result is to MOVE the controller rather than
FEEL the controller.
What the sim pilot has to do to fly the airplane accurately is to first of
all realize that the physical forces (force feedback is totally inaccurate
as well)
are missing and make a conscious effort to counter this by being EXTRA
smooth on the controller. In general, this means possibly rethinking the way
you are using the controller and forcing yourself to think as a pilot would
be thinking. VERY subtle pressures are what is required; probably much less
than you are using on whatever controller you have.
Try this. Put the airplane on a long runway somewhere and begin a takeoff.
VERY gently, apply enough back pressure to raise the nosewheel off the
ground during the takeoff roll. Now simply concentrate on how LITTLE
pressure you need to rotate into a climb attitude, and you'll be well on the
way to solving this issue.
Dudley Henriques
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| Mike, try using 1 'notch' of flaps, dial in some 'up' trim, and apply gentle
backpressure at about 65kts, it should rotate smoothly.
"Mike" <nospam@comcast.net> wrote in message
news:e4ydnQJtWNqkz43ZnZ2dnUVZ_tGdnZ2d@comcast.com...
quote:
>A question for the real world pilots. I know in FS 2004 when in the
>take-off roll in the C172, pulling back smoothly on the yoke makes the
>aircraft literally jump into the air and then I must correct with forward
>pressure. Does this happen in a real C172?
>
> Mike
>
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| Beech45Whiskey 2006-03-09, 7:33 pm |
| PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
quote:
> Mike, try using 1 'notch' of flaps, dial in some 'up' trim, and apply gentle
> backpressure at about 65kts, it should rotate smoothly.
However (<G> )....
The "yoke gently back" speed for a C172SP at maximum gross weight is 55kts.
Any more speed than that and you are trading valuable runway distance for
speed. Also, one notch of flaps is reserved for a short or a soft field
takeoff. No flaps are required on standard runways in this model C172.
I don't have the exact value, but I would recommend that Mike experiment
with the elevator sensitivity. IIRC, this setting is found in the
c172.cfg file (anyone, anyone? I don't remember the exact name of this
setting). Finding a less sensitive value will more closely represent the
real elevator reaction.
--
Peter
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| Beech45Whiskey 2006-03-09, 7:33 pm |
| Beech45Whiskey <pjricc@ZZgmail.com> wrote:
quote:
> Any more speed than that and you are trading valuable runway distance for
> speed.
A clarification: If one allows the C172 to gain more speed than 55kts
before pulling back on the yoke, then one is trading *remaining available
runway* for speed. This results in a pilot's bad habits that reduce the
utility of a C172 at shorter runways.
Also, (excluding short/soft field takeoff) lifting off at 55kts applies
only to a no-gust weather scenario.
In strong, gusty conditions, one *would* allow the aircraft to accelerate
to perhaps 62 kts or so (depends on the gust strength), as well as a bit
more vigorous pull on the yoke. This will allow the aircraft to jump off
the runway and the pilot to establish a quick crab into the wind, lessoning
the chance of being blown sideways or slamming back down to the runway due
to windshear.
--
Peter
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| "PPS" <jgardner@nitroREMOVETHISgraphix.Kom> wrote in message
news:aGYPf.1098$C7.959@bignews2.bellsouth.net...
quote:
> Mike, try using 1 'notch' of flaps, dial in some 'up' trim, and apply
> gentle backpressure at about 65kts, it should rotate smoothly.
Thanks all for the tips. My first reaction was "damn... that'd be pretty
scary if that was realistic  ."
Not having any feedback is probably the worst drawback of the sim. Sometimes
it takes a lot of effort to adjust trim correctly, but I imagine in a real
AC you apply just enough trim to keep the yoke in it's current position.
My flight sensitivities are set all the way to realistic/hard and I do find
that I need very little control pressure to get the desired results. Of
course, the slower the speed, the more effort required. Guess I'll find out
what it's really like someday ;)
Mike
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quote:
> I don't have the exact value, but I would recommend that Mike experiment
> with the elevator sensitivity. IIRC, this setting is found in the
> c172.cfg file (anyone, anyone? I don't remember the exact name of this
> setting). Finding a less sensitive value will more closely represent the
> real elevator reaction.
Yes, sliders all to the right. I didn't edit the file directly because
there's a
Sensitivities menu within the sim where you can set sensitivities
(and null zones) for just about all axes.
Perhaps someone knows of a good C172 add-on that has a more accurate
flight model? I have a couple of PMDG add-ons and they say for the most
realism, set all sliders to the right. I guess they don't rely on FS2004
settings...
Mike
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| Mike wrote:
quote:
> A question for the real world pilots. I know in FS 2004 when in the
> take-off roll in the C172, pulling back smoothly on the yoke makes
> the aircraft literally jump into the air and then I must correct with
> forward pressure. Does this happen in a real C172?
>
No.
Try a few more notches nose down trim, you'll know if you go too far (i.e.
maybe NO take off)..
=(8-0))))
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| You are correct, but if I have the option, I always add a little extra
insurance in case of an engine failure or a wind gust. :-)
"Beech45Whiskey" <pjricc@ZZgmail.com> wrote in message
news:di94phxofjt3.dlg@ID-259643.user.individual.net...
quote:
> PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
>
>
> However (<G> )....
>
> The "yoke gently back" speed for a C172SP at maximum gross weight is
> 55kts.
> Any more speed than that and you are trading valuable runway distance for
> speed. Also, one notch of flaps is reserved for a short or a soft field
> takeoff. No flaps are required on standard runways in this model C172.
>
> I don't have the exact value, but I would recommend that Mike experiment
> with the elevator sensitivity. IIRC, this setting is found in the
> c172.cfg file (anyone, anyone? I don't remember the exact name of this
> setting). Finding a less sensitive value will more closely represent the
> real elevator reaction.
>
> --
> Peter
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| Beech45Whiskey 2006-03-09, 7:33 pm |
| Mike <nospam@comcast.net> wrote:
quote:
> Yes, sliders all to the right. I didn't edit the file directly because
> there's a
> Sensitivities menu within the sim where you can set sensitivities
> (and null zones) for just about all axes.
In addition to these settings, there is also an elevator adjustment in the
c172.cfg file to which I was referring. A few years ago when I flew the
C172 in the sim I recall making adjustments to this setting, as it did more
than the sensitivity settings to which you refer.
Hopefully someone will post the name of that setting in the cfg file for
you to experiment with.
A more realistic, free C172 model can be found at RealAir.com:
http://www.realairsimulations.com/
I would have posted the exact link to the download, but either their site
or my connection is painfully slow. Take a look there for the free
download.
--
Peter
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| Beech45Whiskey 2006-03-09, 7:33 pm |
| PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
quote:
> You are correct, but if I have the option, I always add a little extra
> insurance in case of an engine failure or a wind gust. :-)
Don't forget to add a few knots for the wife, the kids, the extra bags in
the back, and grandma, too.
Seriously, how will the extra speed on the runway help you in the event of
an engine failure at takeoff? If anything, the extra speed on the runway
will eat up the remaining runway and not give you the option for setting it
back down, assuming the engine failure occurred low enough.
--
Peter
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| I fly a lot at MGW(sometimes over) off short fields in high density alt, I'm
outa runway a lot of times by the time I rotate, so the extra speed gives
me a few more options in case I need to put it down off runway.
On a normal runway, you are correct that it would eat up pavement, but the
ones I normally use are either long enough it's not a problem, or short
enough it won't make a difference. There is the occasionly flight where I do
use normal takeoff's, but I don't remember the last one :-)
"Beech45Whiskey" <pjricc@ZZgmail.com> wrote in message
news:zkcqha3dt2ri$.dlg@ID-259643.user.individual.net...
quote:
> PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
>
>
> Don't forget to add a few knots for the wife, the kids, the extra bags in
> the back, and grandma, too.
>
> Seriously, how will the extra speed on the runway help you in the event of
> an engine failure at takeoff? If anything, the extra speed on the runway
> will eat up the remaining runway and not give you the option for setting
> it
> back down, assuming the engine failure occurred low enough.
>
>
>
> --
> Peter
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|
| > In addition to these settings, there is also an elevator adjustment in the
quote:
> c172.cfg file to which I was referring. A few years ago when I flew the
> C172 in the sim I recall making adjustments to this setting, as it did
> more
> than the sensitivity settings to which you refer.
>
> Hopefully someone will post the name of that setting in the cfg file for
> you to experiment with.
>
> A more realistic, free C172 model can be found at RealAir.com:
>
> http://www.realairsimulations.com/
>
> I would have posted the exact link to the download, but either their site
> or my connection is painfully slow. Take a look there for the free
> download.
>
> --
> Peter
Thanks. I'll check it out.
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| Mortimer Schnerd, RN 2006-03-09, 7:33 pm |
| Beech45Whiskey wrote:
quote:
> Beech45Whiskey <pjricc@ZZgmail.com> wrote:
>
>
> A clarification: If one allows the C172 to gain more speed than 55kts
> before pulling back on the yoke, then one is trading *remaining available
> runway* for speed. This results in a pilot's bad habits that reduce the
> utility of a C172 at shorter runways.
In a low wind day, easing the yoke back a little once above stall speed, say at
about 45 knots, will result in the aircraft rolling on the two mains for a time,
then smoothly lifting off around 60 knots or so without any further control
input. It makes for a very nice airline style liftoff in a Cessna. Of course
the climbout is somewhat more muted. <G>
Unfortunately, it doesn't work well in a Cherokee. The Cherokee will just skip
down the runway until it's ready to fly if you do this. Better to keep the
controls neutral until you're ready to fly, then pull it off.
I haven't got enough hours in Beechcraft to form an opinion about their behavior
with this technique.
--
Mortimer Schnerd, RN
mschnerd@carolina.rr.com.REMOVE
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| Beech45Whiskey 2006-03-09, 7:33 pm |
| PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
<snip>
quote:
> On a normal runway, you are correct that it would eat up pavement, but the
> ones I normally use are either long enough it's not a problem, or short
> enough it won't make a difference.
That was the opinion of the person who sold me the V35. When he took me
for a demo flight, he always lifted off at 80kts, regardless of the gross
weight of the aircraft (POH states 70 at full gross), and he always landed
at 95 kts (POH recommends 1.3 VSO, or approx 70, depending on weight and
gusts). His argument was, "hell, you have 9,500 feet of runway here
(Syracuse, NY, a class C airport), and this is how pilots of corporate jets
land."
OK. I stuck to the POH, in the event I ever needed to land or depart an
airport with a much shorter runway. The first time he rode with me after I
purchased the aircraft, the stall warning went off just as the wheels
kissed the runway. He about had a cow.
--
Peter
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| I should have mentioned the 172 I currently fly isn't a standard one, it's
an XP with the 180hp PennYan conversion, STOL kit, and 40* flaps, I get it
to do things like land at 40, pace the Goodyear Blimp, and scare the hell
outa most BFR check pilots when they want a short/soft field demo :-)
"Beech45Whiskey" <pjricc@ZZgmail.com> wrote in message
news:1n21d2nod1zzz.dlg@ID-259643.user.individual.net...
quote:
> PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
>
> <snip>
>
> That was the opinion of the person who sold me the V35. When he took me
> for a demo flight, he always lifted off at 80kts, regardless of the gross
> weight of the aircraft (POH states 70 at full gross), and he always landed
> at 95 kts (POH recommends 1.3 VSO, or approx 70, depending on weight and
> gusts). His argument was, "hell, you have 9,500 feet of runway here
> (Syracuse, NY, a class C airport), and this is how pilots of corporate
> jets
> land."
>
> OK. I stuck to the POH, in the event I ever needed to land or depart an
> airport with a much shorter runway. The first time he rode with me after
> I
> purchased the aircraft, the stall warning went off just as the wheels
> kissed the runway. He about had a cow.
>
> --
> Peter
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| Mortimer Schnerd, RN 2006-03-09, 7:33 pm |
| Beech45Whiskey wrote:
quote:
> OK. I stuck to the POH, in the event I ever needed to land or depart an
> airport with a much shorter runway. The first time he rode with me after I
> purchased the aircraft, the stall warning went off just as the wheels
> kissed the runway. He about had a cow.
The man is afraid of the stall. Back in the days when I flew part 135, I had a
grizzled old USAF colonel as my chief pilot. He trained me to make EVERY
landing a short field landing. That way, if I ever really need to make a short
landing, I don't do anything different.
Some instructors used to get really antsy when I chopped the power while I was
still out a way. The idea wasn't to flare over the numbers. The idea was to
touch down there.
--
Mortimer Schnerd, RN
mschnerd@carolina.rr.com.REMOVE
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| Mortimer Schnerd, RN 2006-03-09, 7:33 pm |
| PPS wrote:
quote:
> I should have mentioned the 172 I currently fly isn't a standard one, it's
> an XP with the 180hp PennYan conversion, STOL kit, and 40* flaps, I get it
> to do things like land at 40, pace the Goodyear Blimp, and scare the hell
> outa most BFR check pilots when they want a short/soft field demo :-)
The FBO I used to fly out of had a C-210 with a Robertson STOL kit installed.
Normal takeoff was at 60 knots, just as if it was a C-172 on steroids. A full
STOL takeoff would scare the crap out of you... pull it off at 42 knots with
more rudder pressure in than a C-402 on one engine. My right leg would shake,
it took so much pressure. But it'd fly....
For those of you who don't know, a standard C-210 is generally flown off at 80
knots.
--
Mortimer Schnerd, RN
mschnerd@carolina.rr.com.REMOVE
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| If ya ain't livin' on the edge, ya ain't livin' :-)
(unless you have passengers on board lol )
"Mortimer Schnerd, RN" <mortschnerd@carolina.rr.com.REMOVE> wrote in message
news:e82Qf.37647$915.18280@southeast.rr.com...
quote:
> PPS wrote:
>
>
> The FBO I used to fly out of had a C-210 with a Robertson STOL kit
> installed. Normal takeoff was at 60 knots, just as if it was a C-172 on
> steroids. A full STOL takeoff would scare the crap out of you... pull it
> off at 42 knots with more rudder pressure in than a C-402 on one engine.
> My right leg would shake, it took so much pressure. But it'd fly....
>
> For those of you who don't know, a standard C-210 is generally flown off
> at 80 knots.
>
>
>
> --
> Mortimer Schnerd, RN
>
> mschnerd@carolina.rr.com.REMOVE
>
>
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| Jan Bijsterbosch 2006-03-10, 7:34 pm |
| Hello Beech45Whiskey,
"Beech45Whiskey" <pjricc@ZZgmail.com> schreef in bericht
news:di94phxofjt3.dlg@ID-259643.user.individual.net...
quote:
> PPS <jgardner@nitroREMOVETHISgraphix.Kom> wrote:
>
[snip][vbcol=seagreen]
> I don't have the exact value, but I would recommend that Mike experiment
> with the elevator sensitivity. IIRC, this setting is found in the
> c172.cfg file (anyone, anyone? I don't remember the exact name of this
> setting).
That would be in the flight_tuning section the entry for
elevator_effectiveness
quote:
> Peter
Greetings from overcast Amsterdam,
Jan
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| Beech45Whiskey 2006-03-10, 7:35 pm |
| Jan Bijsterbosch <bijsterblokit@hccnet.nl> wrote:
quote:
> That would be in the flight_tuning section the entry for
> elevator_effectiveness
Thank you, Jan. Mike, did you catch this? Experiment with Elevator
Effectiveness in the C172.cfg file to reduce the elevator response a bit.
--
Peter
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| Oops, I was snoozin' a bit on this thread. I'll experiment with that...
Thanks.
"Beech45Whiskey" <pjricc@ZZgmail.com> wrote in message
news:wx012luvxyjh.dlg@ID-259643.user.individual.net...
quote:
> Jan Bijsterbosch <bijsterblokit@hccnet.nl> wrote:
>
>
> Thank you, Jan. Mike, did you catch this? Experiment with Elevator
> Effectiveness in the C172.cfg file to reduce the elevator response a bit.
>
> --
> Peter
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