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B-737: low speed limit - why?

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Anonymous
May 14, 2005 6:07:14 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Hi,

There's a white-red striped arrow on the airspeed indicator
in B-737 which, I guess, shows the safe speed limit.

The position of this arrow changes. I wonder - why?
Based on what conditions?

It is usually below 350 kts. Why so low?
Tha manual says that cruise speed of B-737 is 477 kts.

And another quesion, since I'm already here bothering you anyway:

What exactly is a radio-magnetic inditacor (dual needle RMI)?
What does it show?

Thank you,

latet

More about : 737 low speed limit

May 14, 2005 6:07:15 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

477kts would have to be ground speed 350 would be indicated air speed

"latet" <latet@latet.pl> wrote in message
news:D 63fgd$7nc$1@host102-ursus.spray.net.pl...
> Hi,
>
> There's a white-red striped arrow on the airspeed indicator
> in B-737 which, I guess, shows the safe speed limit.
>
> The position of this arrow changes. I wonder - why?
> Based on what conditions?
>
> It is usually below 350 kts. Why so low?
> Tha manual says that cruise speed of B-737 is 477 kts.
>
> And another quesion, since I'm already here bothering you anyway:
>
> What exactly is a radio-magnetic inditacor (dual needle RMI)?
> What does it show?
>
> Thank you,
>
> latet
>
>
May 14, 2005 6:07:16 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

As you climb, you will notice the red and white arrow move downwards
indicating lower maximum indicated airspeed. This is because the air is
thinner as you climb thereby reducing the amount of air activating the IAS
indicator, even though your groundspeed will either remain the same or
increase. Watch the needle decrease as you climb and if the other needle
goes over it, you will receive an overspeed alarm.

Hope this helps,
Arthur

"Petebert" <castle@nthrax.org> wrote in message
news:FFbhe.45$H85.1510@news.uswest.net...
> 477kts would have to be ground speed 350 would be indicated air speed
>
> "latet" <latet@latet.pl> wrote in message
> news:D 63fgd$7nc$1@host102-ursus.spray.net.pl...
>> Hi,
>>
>> There's a white-red striped arrow on the airspeed indicator
>> in B-737 which, I guess, shows the safe speed limit.
>>
>> The position of this arrow changes. I wonder - why?
>> Based on what conditions?
>>
>> It is usually below 350 kts. Why so low?
>> Tha manual says that cruise speed of B-737 is 477 kts.
>>
>> And another quesion, since I'm already here bothering you anyway:
>>
>> What exactly is a radio-magnetic inditacor (dual needle RMI)?
>> What does it show?
>>
>> Thank you,
>>
>> latet
>>
>>
>
>
Related resources
May 14, 2005 11:03:56 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

latet wrote:

> Hi,
>
> There's a white-red striped arrow on the airspeed indicator
> in B-737 which, I guess, shows the safe speed limit.
>
> The position of this arrow changes. I wonder - why?
> Based on what conditions?
>
> It is usually below 350 kts. Why so low?
> Tha manual says that cruise speed of B-737 is 477 kts.
>
> And another quesion, since I'm already here bothering you anyway:
>
> What exactly is a radio-magnetic inditacor (dual needle RMI)?
> What does it show?
>
> Thank you,
>
> latet
>
>

Since I hated instrument flying for 25 years I always leave the IFR
questions to those more knowledgeable in the mystic procedures called
"flying blind"

But since I had a humorous incident on my very first IFR checkride.

First though, the dual needle RMI has a thin arrow which points to your
NDB station (or AM Radio Station) that you have tuned on your ADF. The
second, and wider needle is for your VOR, usually VOR #1.

So here's a teaser for some of the iffer pilots. On my initial
checkride I had a stuck card failure. The face of the RMI no longer
turned. If it's stuck on 270 degrees say, no matter where you turn or
what heading you fly, the RMI face is stuck showing 270 degrees. The
needles are operative and are correct. The MAG Compass shows the
heading to be 090 Degrees.

The #1 needle is pointed 90 degrees to the right of the 12 o'clock
position (270) of the RMI which, if I'm not wrong, would be pointed at
the number 360 or 0, whatever.

And the #2 needle (VOR) is pointed left 90 degrees from the top of the
RMI, which, if I'm correct, pointing at the number 180.

Let's make it easy. Say you wanted to track inbound from your present
position to the NDB. Which direction would you turn the aircraft and how
many degrees would you turn. When you roll out on the inbound track,
what would the Mag Compass show? (Plus or minus, I know by the time the
turn is completed you might be showing a track inbound a couple degrees off)



But before you turn you suddenly realize you need to go to the VOR that
you have tuned in.


(Remember- the #2 needle (VOR) is pointed left 90 degrees from the top
of the RMI, which, if I'm correct, pointing at the number 180.)

To track inbound to the VOR from your present position, which direction
would you turn the aircraft and how many degrees? What heading would
show on the Mag Compass when you were leveled off and tracking inbound?

--

boB,
Master_Caution_70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)
Anonymous
May 14, 2005 2:50:59 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

> As you climb, you will notice the red and white arrow move downwards
> indicating lower maximum indicated airspeed. This is because the air is
> thinner as you climb thereby reducing the amount of air activating the IAS
> indicator, even though your groundspeed will either remain the same or
> increase.

Thanks.
OK, it's clear to my now why in thinner air - indicated air speed
gets lower than the true ground speed is.
But why - in thinner air - the safe airspeed has to be lower?
What destroys my aircraft when it overspeeds? Not the air
going too fast?

MsFS gives me an option of showing "real speed" instead of
indicated air speed. There's no such option in real planes, is it?
Would it be useful?

Thanks,

latet
May 14, 2005 2:51:00 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

the safe airspeed is higher, at 3000' exceed the speed limit and see what
your mach is and try it again at 30,000'

"latet" <latet@latet.pl> wrote in message
news:D 64e67$qfr$1@host102-ursus.spray.net.pl...
>> As you climb, you will notice the red and white arrow move downwards
>> indicating lower maximum indicated airspeed. This is because the air is
>> thinner as you climb thereby reducing the amount of air activating the
>> IAS indicator, even though your groundspeed will either remain the same
>> or increase.
>
> Thanks.
> OK, it's clear to my now why in thinner air - indicated air speed
> gets lower than the true ground speed is.
> But why - in thinner air - the safe airspeed has to be lower?
> What destroys my aircraft when it overspeeds? Not the air
> going too fast?
>
> MsFS gives me an option of showing "real speed" instead of
> indicated air speed. There's no such option in real planes, is it?
> Would it be useful?
>
> Thanks,
>
> latet
>
Anonymous
May 14, 2005 2:51:00 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

"latet" <latet@latet.pl> wrote in message
news:D 64e67$qfr$1@host102-ursus.spray.net.pl...
> Thanks.
> OK, it's clear to my now why in thinner air - indicated air speed
> gets lower than the true ground speed is.
> But why - in thinner air - the safe airspeed has to be lower?
> What destroys my aircraft when it overspeeds? Not the air
> going too fast?
>
> MsFS gives me an option of showing "real speed" instead of
> indicated air speed. There's no such option in real planes, is it?
> Would it be useful?
>
> Thanks,
>
> latet

Latet,

You appear to be confused by the difference between True Airspeed, Indicated
Air Speed, and Ground Speed (which in itself is merely True Airpseed as
affected by the wind at flight altitude)

Here is a great explantion on the subject--saves me a lot of typing. Hal
Stoen has numerous tutorials on his web site, all excellent. This is just
one.

http://www.stoenworks.com/Tutorials/Understanding%20air...

HTH,
Paul
>
Anonymous
May 14, 2005 4:36:06 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

"boB" <akitaREMOVECAPS77@excite.Icom> wrote in message
news:wphhe.86596$hu5.7583@tornado.texas.rr.com...
> Since I hated instrument flying for 25 years I always leave the IFR
> questions to those more knowledgeable in the mystic procedures called
> "flying blind"
>
> But since I had a humorous incident on my very first IFR checkride.
>
> First though, the dual needle RMI has a thin arrow which points to your
> NDB station (or AM Radio Station) that you have tuned on your ADF. The
> second, and wider needle is for your VOR, usually VOR #1.
>
> So here's a teaser for some of the iffer pilots. On my initial checkride
> I had a stuck card failure. The face of the RMI no longer turned. If it's
> stuck on 270 degrees say, no matter where you turn or what heading you
> fly, the RMI face is stuck showing 270 degrees. The needles are operative
> and are correct. The MAG Compass shows the heading to be 090 Degrees.
>
> The #1 needle is pointed 90 degrees to the right of the 12 o'clock
> position (270) of the RMI which, if I'm not wrong, would be pointed at the
> number 360 or 0, whatever.
>
> And the #2 needle (VOR) is pointed left 90 degrees from the top of the
> RMI, which, if I'm correct, pointing at the number 180.
>
> Let's make it easy. Say you wanted to track inbound from your present
> position to the NDB. Which direction would you turn the aircraft and how
> many degrees would you turn. When you roll out on the inbound track, what
> would the Mag Compass show? (Plus or minus, I know by the time the turn
> is completed you might be showing a track inbound a couple degrees off)
>
>
>
> But before you turn you suddenly realize you need to go to the VOR that
> you have tuned in.
>
>
> (Remember- the #2 needle (VOR) is pointed left 90 degrees from the top of
> the RMI, which, if I'm correct, pointing at the number 180.)
>
> To track inbound to the VOR from your present position, which direction
> would you turn the aircraft and how many degrees? What heading would show
> on the Mag Compass when you were leveled off and tracking inbound?
>
> --
>
> boB,
> Master_Caution_70
>
> U.S. Army Aviation (retired)
> Central Texas - 5NM West of Gray Army Airfield (KGRK)

Hi boB,

The first 5 years I was flying instruments (FW only), all we had in the L-20
and TL-19D was a fixed card ADF. And RMI was unheard of then--our "rich
uncle" did not believe in spending money on frivolous stuff! :-))

So what you describe is nothing more than a fixed card situation with the
RMI that is the same as with the old ADF indicators. Needles are working
correctly and show a RELATIVE BEARING from the nose of the aircraft TO the
station in question. In any case, fixed card OR moving card, the nose of
either needle will always point TO the respective station.

To go to the NDB, turn RIGHT 90 degrees to a heading of 180 on the mag
compass. To go to the VOR, turn LEFT 90 degrees to a heading of 360 on the
mag compass. For starters.

This heading is only correct momentarily, since wind will have an effect on
your track. Remember, "push on the nose, pull on the tail" of a needle,
depending on whether you are tracking TO or FROM the station respectively.
Once you have the initial track determined, then wind correction to maintain
that track is the same process whether you are using a fixed card or moving
card.

Of course, one can always keep the nose of the needle at the top of the card
and fly a "great circle route" to the station. :-))

Regards,
Paul
Anonymous
May 14, 2005 8:09:39 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

> the safe airspeed is higher, at 3000' exceed the speed limit and see what
> your mach is and try it again at 30,000'

Isn't the mach speed simply a math calculation of the airspeed in kts?

Thanks,

latet
Anonymous
May 14, 2005 8:09:40 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

No, I believe the Mach number is a percentage of the speed of sound at that
particular altitude.
Mach 1 being the speed of sound, Mach 2, twice the speed of sound etc...




Cheers,

Quilly











An individual reply goes into my spam filter
May 15, 2005 3:35:13 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Paul Riley wrote:

> "boB" <akitaREMOVECAPS77@excite.Icom> wrote in message
> news:wphhe.86596$hu5.7583@tornado.texas.rr.com...
>
>>Since I hated instrument flying for 25 years I always leave the IFR
>>questions to those more knowledgeable in the mystic procedures called
>>"flying blind"
>>
>>But since I had a humorous incident on my very first IFR checkride.
>>
>>First though, the dual needle RMI has a thin arrow which points to your
>>NDB station (or AM Radio Station) that you have tuned on your ADF. The
>>second, and wider needle is for your VOR, usually VOR #1.
>>
>>So here's a teaser for some of the iffer pilots. On my initial checkride
>>I had a stuck card failure. The face of the RMI no longer turned. If it's
>>stuck on 270 degrees say, no matter where you turn or what heading you
>>fly, the RMI face is stuck showing 270 degrees. The needles are operative
>>and are correct. The MAG Compass shows the heading to be 090 Degrees.
>>
>>The #1 needle is pointed 90 degrees to the right of the 12 o'clock
>>position (270) of the RMI which, if I'm not wrong, would be pointed at the
>>number 360 or 0, whatever.
>>
>>And the #2 needle (VOR) is pointed left 90 degrees from the top of the
>>RMI, which, if I'm correct, pointing at the number 180.
>>
>>Let's make it easy. Say you wanted to track inbound from your present
>>position to the NDB. Which direction would you turn the aircraft and how
>>many degrees would you turn. When you roll out on the inbound track, what
>>would the Mag Compass show? (Plus or minus, I know by the time the turn
>>is completed you might be showing a track inbound a couple degrees off)
>>
>>
>>
>>But before you turn you suddenly realize you need to go to the VOR that
>>you have tuned in.
>>
>>
>>(Remember- the #2 needle (VOR) is pointed left 90 degrees from the top of
>>the RMI, which, if I'm correct, pointing at the number 180.)
>>
>>To track inbound to the VOR from your present position, which direction
>>would you turn the aircraft and how many degrees? What heading would show
>>on the Mag Compass when you were leveled off and tracking inbound?
>>
>>--
>>
>>boB,
>>Master_Caution_70
>>
>>U.S. Army Aviation (retired)
>>Central Texas - 5NM West of Gray Army Airfield (KGRK)
>
>
> Hi boB,
>
> The first 5 years I was flying instruments (FW only), all we had in the L-20
> and TL-19D was a fixed card ADF. And RMI was unheard of then--our "rich
> uncle" did not believe in spending money on frivolous stuff! :-))
>
> So what you describe is nothing more than a fixed card situation with the
> RMI that is the same as with the old ADF indicators. Needles are working
> correctly and show a RELATIVE BEARING from the nose of the aircraft TO the
> station in question. In any case, fixed card OR moving card, the nose of
> either needle will always point TO the respective station.
>
> To go to the NDB, turn RIGHT 90 degrees to a heading of 180 on the mag
> compass. To go to the VOR, turn LEFT 90 degrees to a heading of 360 on the
> mag compass. For starters.
>
> This heading is only correct momentarily, since wind will have an effect on
> your track. Remember, "push on the nose, pull on the tail" of a needle,
> depending on whether you are tracking TO or FROM the station respectively.
> Once you have the initial track determined, then wind correction to maintain
> that track is the same process whether you are using a fixed card or moving
> card.

> Regards,
> Paul
>

Yep, the ADF needle always points to the station so turn right 90
degrees to a heading of 180.

But a stuck card RMI is different. The VOR needle will always point to
the heading required to get to the VOR. So the VOR needle is pointing
left 90 degrees to a heading of 360 degrees. You turn left to 360
degrees. Maintaining a straight ground track is a workload.

The reason I brought this situation up was it was exactly what I faced
at the end of my initial standard instrument evaluation in a Bell 47 (OH-13)

I was given directions to fly to and cross the cairns VOR at a certain
altitude. I was just about to turn left to the point of the VOR needle
when the IP took the controls. One of my classmates had a mid-air over
by that stagefield not too far outside the Ozark gate on the left.

After the Evaluator took the controls he suddenly realized where I was
starting to turn and he asked me, "were you turning left to the VOR?" I
said "of course not, the VOR needle points to the mag heading inbound to
the VOR. He passed me :) 


--

boB,
Master_Caution_70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)
Anonymous
May 15, 2005 3:35:14 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

HI boB,

Leaving your post AND mine in --please see toward the bottom for my
additional comments--inserted.
"boB" <akitaREMOVECAPS77@excite.Icom> wrote in message
news:RWvhe.87096$hu5.45993@tornado.texas.rr.com...
> Paul Riley wrote:
>
>> "boB" <akitaREMOVECAPS77@excite.Icom> wrote in message
>> news:wphhe.86596$hu5.7583@tornado.texas.rr.com...
>>
>>>Since I hated instrument flying for 25 years I always leave the IFR
>>>questions to those more knowledgeable in the mystic procedures called
>>>"flying blind"
>>>
>>>But since I had a humorous incident on my very first IFR checkride.
>>>
>>>First though, the dual needle RMI has a thin arrow which points to your
>>>NDB station (or AM Radio Station) that you have tuned on your ADF. The
>>>second, and wider needle is for your VOR, usually VOR #1.
>>>
>>>So here's a teaser for some of the iffer pilots. On my initial checkride
>>>I had a stuck card failure. The face of the RMI no longer turned. If
>>>it's
>>>stuck on 270 degrees say, no matter where you turn or what heading you
>>>fly, the RMI face is stuck showing 270 degrees. The needles are operative
>>>and are correct. The MAG Compass shows the heading to be 090 Degrees.
>>>
>>>The #1 needle is pointed 90 degrees to the right of the 12 o'clock
>>>position (270) of the RMI which, if I'm not wrong, would be pointed at
>>>the
>>>number 360 or 0, whatever.
>>>
>>>And the #2 needle (VOR) is pointed left 90 degrees from the top of the
>>>RMI, which, if I'm correct, pointing at the number 180.
>>>
>>>Let's make it easy. Say you wanted to track inbound from your present
>>>position to the NDB. Which direction would you turn the aircraft and how
>>>many degrees would you turn. When you roll out on the inbound track, what
>>>would the Mag Compass show? (Plus or minus, I know by the time the turn
>>>is completed you might be showing a track inbound a couple degrees off)
>>>
>>>
>>>
>>>But before you turn you suddenly realize you need to go to the VOR that
>>>you have tuned in.
>>>
>>>
>>>(Remember- the #2 needle (VOR) is pointed left 90 degrees from the top of
>>>the RMI, which, if I'm correct, pointing at the number 180.)
>>>
>>>To track inbound to the VOR from your present position, which direction
>>>would you turn the aircraft and how many degrees? What heading would show
>>>on the Mag Compass when you were leveled off and tracking inbound?
>>>
>>>--
>>>
>>>boB,
>>>Master_Caution_70
>>>
>>>U.S. Army Aviation (retired)
>>>Central Texas - 5NM West of Gray Army Airfield (KGRK)
>>
>>
>> Hi boB,
>>
>> The first 5 years I was flying instruments (FW only), all we had in the
>> L-20
>> and TL-19D was a fixed card ADF. And RMI was unheard of then--our "rich
>> uncle" did not believe in spending money on frivolous stuff! :-))
>>
>> So what you describe is nothing more than a fixed card situation with the
>> RMI that is the same as with the old ADF indicators. Needles are working
>> correctly and show a RELATIVE BEARING from the nose of the aircraft TO
>> the
>> station in question. In any case, fixed card OR moving card, the nose of
>> either needle will always point TO the respective station.
>>
>> To go to the NDB, turn RIGHT 90 degrees to a heading of 180 on the mag
>> compass. To go to the VOR, turn LEFT 90 degrees to a heading of 360 on
>> the mag compass. For starters.
>>
>> This heading is only correct momentarily, since wind will have an effect
>> on
>> your track. Remember, "push on the nose, pull on the tail" of a needle,
>> depending on whether you are tracking TO or FROM the station
>> respectively.
>> Once you have the initial track determined, then wind correction to
>> maintain
>> that track is the same process whether you are using a fixed card or
>> moving
>> card.
>
>> Regards,
>> Paul
>>
>
> Yep, the ADF needle always points to the station so turn right 90 degrees
> to a heading of 180.
>
> But a stuck card RMI is different. The VOR needle will always point to
> the heading required to get to the VOR. So the VOR needle is pointing left
> 90 degrees to a heading of 360 degrees. You turn left to 360 degrees.
> Maintaining a straight ground track is a workload.

OK, this is confusing. Typo maybe. You said the #2 needle is pointed LEFT 90
degrees on the "fixed" card, which as you also said, is 180. I agree with
that, since the top of the card is now reading 270 So with the VOR on a
fixed, frozen card RMI always pointing to the heading to the VOR (different
than an ADF in this case), then it would have to be pointing RIGHT 90
degrees to make 360 the heading to the station. Otherwise, the heading to
the VOR station is 180, not 360 with the needle 90 left. And I would turn
RIGHT from my current aircraft heading of 090.

On the other hand, if it is a relative bearing to the VOR as I was thinking
then 90 degrees LEFT of the aircraft heading of 090 is 360.

I really do not remember this point, but accept what you say as far as the
difference between ADF needle and VOR needle with fixed RMI card. To be
honest, I have not gone into any of this in ~ 30 years, so will plead senior
moment. :-))) Would appreciate clarification though.

Regards,
Paul
PS This would be a lot easier if we could both sit down together with paper
and pencil over a couple of beers :-))
May 15, 2005 7:08:45 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Paul Riley wrote:

> HI boB,
>
> Leaving your post AND mine in --please see toward the bottom for my
> additional comments--inserted.
> "boB" <akitaREMOVECAPS77@excite.Icom> wrote in message
> news:RWvhe.87096$hu5.45993@tornado.texas.rr.com...
>
>>Paul Riley wrote:

>
> Regards,
> Paul
> PS This would be a lot easier if we could both sit down together with paper
> and pencil over a couple of beers :-))
>
>
>

Damn!!! OK, I'll look it up. :) 

--

boB,
Master_Caution_70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)
May 15, 2005 7:50:43 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Paul Riley wrote:

> HI boB,
>
> Leaving your post AND mine in --please see toward the bottom for my
> additional comments--inserted.
> "boB" <akitaREMOVECAPS77@excite.Icom> wrote in message
> news:RWvhe.87096$hu5.45993@tornado.texas.rr.com...
>
>>Paul Riley wrote:

> OK, this is confusing. Typo maybe. You said the #2 needle is pointed LEFT 90
> degrees on the "fixed" card, which as you also said, is 180. I agree with
> that, since the top of the card is now reading 270 So with the VOR on a
> fixed, frozen card RMI always pointing to the heading to the VOR (different
> than an ADF in this case), then it would have to be pointing RIGHT 90
> degrees to make 360 the heading to the station. Otherwise, the heading to
> the VOR station is 180, not 360 with the needle 90 left. And I would turn
> RIGHT from my current aircraft heading of 090.

You are correct. I made the mistake even a student pilot might not make
about radials and bearings. It's been a while. Maybe I'll stop the
ILS's and do some VOR stuff.



>
> I really do not remember this point, but accept what you say as far as the
> difference between ADF needle and VOR needle with fixed RMI card. To be
> honest, I have not gone into any of this in ~ 30 years, so will plead senior
> moment. :-))) Would appreciate clarification though.
>
> Regards,
> Paul
> PS This would be a lot easier if we could both sit down together with paper
> and pencil over a couple of beers :-))

I'm still looking but I remember the instant quite well since it almost
caused me to fail my initial instrument checkride. It's hard to forget
those times. Wish I was back there now. :) 


--

boB,
Master_Caution_70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)
Anonymous
May 19, 2005 11:15:44 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

"latet" <latet@latet.pl> wrote in message news:D 64e67$qfr$1@host102-ursus.spray.net.pl...
>> As you climb, you will notice the red and white arrow move downwards indicating lower maximum indicated airspeed. This is
>> because the air is thinner as you climb thereby reducing the amount of air activating the IAS indicator, even though your
>> groundspeed will either remain the same or increase.
>
> Thanks.
> OK, it's clear to my now why in thinner air - indicated air speed
> gets lower than the true ground speed is.
> But why - in thinner air - the safe airspeed has to be lower?
> What destroys my aircraft when it overspeeds? Not the air
> going too fast?
>
At higher altitude, you approach MACH, the speed of sound, which is compressing a shock wave
over the wings and fuselage of the aircraft. The higher you go, the lower the indicated airspeed will
read at the speed of sound, or mach.


> MsFS gives me an option of showing "real speed" instead of
> indicated air speed. There's no such option in real planes, is it?
> Would it be useful?
>
You can read the ground speed using the vor, and dim, which will tell you distance from
the vor, and the speed you are approaching it, or leaving it. Of course you have to be
going directly toward, or away from the vor to get the most accurate reading.

To have the speedo read the indicated air speed is better to see what your plane
is seeing, for instance, let's say you are landing in the mountains at 8000 feet. Your plane
will still land at say 70 mph indicated, just like at sea level, but your ground speed may
be more like 90 mph or more in true ground speed. If you were to only use ground
speed instead of indicated air speed, you would not know where your stall speed is
at different altitudes, or your never exceed speeds for flaps and wing loading.

SeeYaa:)  Harbin



> Thanks,
>
> latet
>
!