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Plane Stopped in Midair



 
 
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  #1  
Old November 11th 04, 04:10 PM
DM
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Default Plane Stopped in Midair

Yesterday I saw a cargo jet (a major air express company) come to what
seemed like a dead stop in midair as it was making its ascent. After
about 20 - 30 seconds of hanging without dropping out of the sky, it
continued climbing and apparently did not crash. There's been nothing
about it in the local news but I've still been very concerned. Could
someone here explain how such a thing is possible?

Some details: the temperature was about 50 degrees F, the sky was mostly
clear, and the time was around 0645. I was traveling by car at about 40
MPH on a street that is parallel to a regular flight path. From this
street it's common to see 3 or 4 planes per minute either climbing or
descending; the airport is about a mile or two away from this particular
street.

As I was moving relatively slowly compared to the how fast the jet
should have been moving, I noticed that I was gaining on it. I quickly
eyeballed the area for tall buildings and other geographical reference
points so I could be sure that I had a good perspective and wasn't just
"seeing things". The object was either not moving or it was moving
*very* slowly, and it was not a helicopter. For a few seconds I was
stopped at an intersection looking at this hanging plane and at the
people in the other cars around me. No one else seemed to be paying any
attention to it besides me.

The main reason this bothered me so much is because had the plane
fallen, it would have landed less than a half mile from where I and
about 30 other running cars were, in addition to several warehouse-type
buildings and auto repair garages, plus a 6 or 8 lane freeway filled
with morning traffic. Since the plane had just taken off and was
probably full of fuel, and was still low enough for its markings to be
readable from the ground, the crash probably would have been
extraordinarily disastrous.

I've done a lot of Googling to try to get an understanding of what I saw
and really haven't learned anything meaningful. I'm hoping someone here
can explain how a "regular" jet--versus a specialized military jet--can
apparently stop in midair and not drop from the sky. As a daily traveler
near a major metro airport, I'd really like to be reassured that this is
not a common occurrence.

Debbie
  #2  
Old November 11th 04, 04:17 PM
BeaglePig
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Posts: n/a
Default

DM wrote in
:

Yesterday I saw a cargo jet (a major air express company) come to what
seemed like a dead stop in midair as it was making its ascent. After
about 20 - 30 seconds of hanging without dropping out of the sky, it
continued climbing and apparently did not crash. There's been nothing
about it in the local news but I've still been very concerned. Could
someone here explain how such a thing is possible?

Some details: the temperature was about 50 degrees F, the sky was
mostly clear, and the time was around 0645. I was traveling by car at
about 40 MPH on a street that is parallel to a regular flight path.
From this street it's common to see 3 or 4 planes per minute either
climbing or descending; the airport is about a mile or two away from
this particular street.

As I was moving relatively slowly compared to the how fast the jet
should have been moving, I noticed that I was gaining on it. I quickly
eyeballed the area for tall buildings and other geographical reference
points so I could be sure that I had a good perspective and wasn't
just "seeing things". The object was either not moving or it was
moving *very* slowly, and it was not a helicopter. For a few seconds I
was stopped at an intersection looking at this hanging plane and at
the people in the other cars around me. No one else seemed to be
paying any attention to it besides me.

The main reason this bothered me so much is because had the plane
fallen, it would have landed less than a half mile from where I and
about 30 other running cars were, in addition to several
warehouse-type buildings and auto repair garages, plus a 6 or 8 lane
freeway filled with morning traffic. Since the plane had just taken
off and was probably full of fuel, and was still low enough for its
markings to be readable from the ground, the crash probably would have
been extraordinarily disastrous.

I've done a lot of Googling to try to get an understanding of what I
saw and really haven't learned anything meaningful. I'm hoping someone
here can explain how a "regular" jet--versus a specialized military
jet--can apparently stop in midair and not drop from the sky. As a
daily traveler near a major metro airport, I'd really like to be
reassured that this is not a common occurrence.

Debbie



It is just your perception, and the relative size of the plane, verses
the size your brain thinks it "out to be". The plane was likely also
either angled at something less than a 45degree angle either toward you,
or awayfrom you making it difficult to percieve movement.

It was not hovering or anything like it.

BeaglePig
  #3  
Old November 11th 04, 04:37 PM
Christopher Brian Colohan
external usenet poster
 
Posts: n/a
Default

DM writes:
Yesterday I saw a cargo jet (a major air express company) come to what
seemed like a dead stop in midair as it was making its ascent. After
about 20 - 30 seconds of hanging without dropping out of the sky, it
continued climbing and apparently did not crash. There's been nothing
about it in the local news but I've still been very concerned. Could
someone here explain how such a thing is possible?

Some details: the temperature was about 50 degrees F, the sky was
mostly clear, and the time was around 0645. I was traveling by car at
about 40 MPH on a street that is parallel to a regular flight
path. From this street it's common to see 3 or 4 planes per minute
either climbing or descending; the airport is about a mile or two away
from this particular street.


One detail you left out -- how windy was it? I'm going to guess it
was a really windy day. If the plane was taking off into a strong
headwind then it would not have to go nearly as fast (relative to the
ground) to stay in the air. The only thing the plane cares about is
how fast it is going relative to the wind (airspeed). You may have
seen a plane which was travelling at a much slower groundspeed than
you are used to seeing, and thought it was almost stopped as a result.

Also, if seems to be windy at ground level where you are, it may be
much windier once you get up above any trees/buildings/etc which only
slow the wind down.

Chris
--
Chris Colohan Email: PGP: finger
Web:
www.colohan.com Phone: (412)268-4751
  #4  
Old November 11th 04, 05:10 PM
John T Lowry
external usenet poster
 
Posts: n/a
Default


"DM" wrote in message
...
Yesterday I saw a cargo jet (a major air express company) come to what
seemed like a dead stop in midair as it was making its ascent. After
about 20 - 30 seconds of hanging without dropping out of the sky, it
continued climbing and apparently did not crash. There's been nothing
about it in the local news but I've still been very concerned. Could
someone here explain how such a thing is possible?

Some details: the temperature was about 50 degrees F, the sky was
mostly clear, and the time was around 0645. I was traveling by car at
about 40 MPH on a street that is parallel to a regular flight path.
From this street it's common to see 3 or 4 planes per minute either
climbing or descending; the airport is about a mile or two away from
this particular street.

As I was moving relatively slowly compared to the how fast the jet
should have been moving, I noticed that I was gaining on it. I quickly
eyeballed the area for tall buildings and other geographical reference
points so I could be sure that I had a good perspective and wasn't
just "seeing things". The object was either not moving or it was
moving *very* slowly, and it was not a helicopter. For a few seconds I
was stopped at an intersection looking at this hanging plane and at
the people in the other cars around me. No one else seemed to be
paying any attention to it besides me.

The main reason this bothered me so much is because had the plane
fallen, it would have landed less than a half mile from where I and
about 30 other running cars were, in addition to several
warehouse-type buildings and auto repair garages, plus a 6 or 8 lane
freeway filled with morning traffic. Since the plane had just taken
off and was probably full of fuel, and was still low enough for its
markings to be readable from the ground, the crash probably would have
been extraordinarily disastrous.

I've done a lot of Googling to try to get an understanding of what I
saw and really haven't learned anything meaningful. I'm hoping someone
here can explain how a "regular" jet--versus a specialized military
jet--can apparently stop in midair and not drop from the sky. As a
daily traveler near a major metro airport, I'd really like to be
reassured that this is not a common occurrence.

Debbie


A pilot acquaintance of mine in Montana (Larry) flies a Super Cub to
inspect pipelines. Sometimes, when it's windy, he confounds drivers on
the Interstate by flying backwards above them. Not a problem; it's only
airspeed that matters.

John Lowry
Flight Physics


  #5  
Old November 11th 04, 05:13 PM
Dylan Smith
external usenet poster
 
Posts: n/a
Default

In article , BeaglePig wrote:
It is just your perception, and the relative size of the plane, verses
the size your brain thinks it "out to be". The plane was likely also
either angled at something less than a 45degree angle either toward you,
or awayfrom you making it difficult to percieve movement.


Especially the giant Antanovs - they look like they are barely moving on
approach, despite really moving at 150 knots or so. By comparison,
a C140 approaching at 55 knots looks like it's just racing along.

--
Dylan Smith, Castletown, Isle of Man
Flying: http://www.dylansmith.net
Frontier Elite Universe: http://www.alioth.net
"Maintain thine airspeed, lest the ground come up and smite thee"
  #6  
Old November 11th 04, 05:18 PM
jharper aaatttt cisco dddooottt com
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Default

One thing to add to what the other posters have said...
in a climbing turn a plane can easily appear to be
stationary for a short while. Not sure about the optics
of this but from my office area I can see planes taking
off from San Jose and starting the right turn for the
standard departure course, and this illusion is quite
common. Combine that with a strong headwind and the effect
of the size of the plane, and you could easily believe it
had stopped.

John

  #7  
Old November 11th 04, 05:38 PM
jharper aaatttt cisco dddooottt com
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One other thing... it's essentially impossible to
stop a fixed-wing airplane in midair. (You can have
zero ground speed due to headwinds, but not zero
airspeed). If you try, the nose drops and it glides
towards the ground. If you try to stop that, it will
eventually perform an aerodynamic stall, which WILL
make the nose drop, but it still won't come to a halt.
About the only way to reach zero airspeed is to
pull the plane into a near-vertical climb. And even
then it reacts by dropping the nose and building
up some speed again (or if you are truly vertical,
it can fall tail-first and then it will at some point
snap into a more normal posture and then start
to fly nose-first again). It's fun to do though, in
the right kind of airplane - a small aerobatic one -
and with enough altitude.

John

  #8  
Old November 11th 04, 05:40 PM
C Kingsbury
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Default

Debbie,

A large transport jet (such as a DC-10 operated by FedEx) can climb, lightly
loaded, at speeds around 150mph. This would be unusual (170-200mph is more
normal) but well short of impossible. It might have been a maintenance
flight, for instance.

Now, with that in mind let's apply a few more factors. First, windspeed.
Let's say the wind is blowing at 40mph. This would not be unusual for the
Northern half of the country this time of year. An airplane flying into that
wind would only need to move at 110mph relative to the ground. Windspeed can
vary strongly from the ground to the first few thousand feet as well, so you
might not have noticed the wondspeed on the ground. Now, you also mentioned
you were in the car going at least 40mph, so relative to you, the plane
would only appear to be moving at 70mph.

Last, you need to do a little trigonometry, I'm afraid. Imagine putting a
ladder up against the side of your house. The ladder goes up ten feet, and
at its base is set back perhaps three or four feet from the house. Now, when
you climb that ladder, you are traveling ten feet, but you only move forward
three or four. A similar thing is going on when you compare your speed in
the car to the plane's speed in the air. So we can reduce the difference to
perhaps 55 or 60mph.

What you perceive as speed is going to be based on changes in angle, in
other words, you expect to see the plane "pulling ahead of you" at a certain
rate. It turns out that the human eye is quite poor at judging small angles.
A speed difference of 60mph at a distance of half a mile is going to produce
very small angular changes, which your eye will not perceive well. So, even
though the plane is moving at sufficient speed to fly quite safely, to your
eye it will appear to be standing still.

I can assure you that even us pilots, who know all these things, still often
see the very same illusion you describe, especially with very large
airplanes. It's simply a combination of factors that produce an overwhelming
optical illusion.

-cwk.


  #9  
Old November 11th 04, 05:48 PM
Darrell S
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Posts: n/a
Default

"As I was moving relatively slowly" quoting from your post, it sounds like
you were in your car driving. The APPARENT relative movement of an aircraft
being observed from a moving vehicle changes drastically if either the
aircraft or the car change relative headings. That could make it appear as
if the forward motion of the jet had stopped.
As for then "it continued climbing" is hard to explain. Perhaps you just
thought it had stopped climbing due to the apparent stoppage of any forward
movement.

--

Darrell R. Schmidt
B-58 Hustler History: http://members.cox.net/dschmidt1/
-

"DM" wrote in message
...
Yesterday I saw a cargo jet (a major air express company) come to what
seemed like a dead stop in midair as it was making its ascent. After about
20 - 30 seconds of hanging without dropping out of the sky, it continued
climbing and apparently did not crash. There's been nothing about it in
the local news but I've still been very concerned. Could someone here
explain how such a thing is possible?

Some details: the temperature was about 50 degrees F, the sky was mostly
clear, and the time was around 0645. I was traveling by car at about 40
MPH on a street that is parallel to a regular flight path. From this
street it's common to see 3 or 4 planes per minute either climbing or
descending; the airport is about a mile or two away from this particular
street.

As I was moving relatively slowly compared to the how fast the jet should
have been moving, I noticed that I was gaining on it. I quickly eyeballed
the area for tall buildings and other geographical reference points so I
could be sure that I had a good perspective and wasn't just "seeing
things". The object was either not moving or it was moving *very* slowly,
and it was not a helicopter. For a few seconds I was stopped at an
intersection looking at this hanging plane and at the people in the other
cars around me. No one else seemed to be paying any attention to it
besides me.

The main reason this bothered me so much is because had the plane fallen,
it would have landed less than a half mile from where I and about 30 other
running cars were, in addition to several warehouse-type buildings and
auto repair garages, plus a 6 or 8 lane freeway filled with morning
traffic. Since the plane had just taken off and was probably full of fuel,
and was still low enough for its markings to be readable from the ground,
the crash probably would have been extraordinarily disastrous.

I've done a lot of Googling to try to get an understanding of what I saw
and really haven't learned anything meaningful. I'm hoping someone here
can explain how a "regular" jet--versus a specialized military jet--can
apparently stop in midair and not drop from the sky. As a daily traveler
near a major metro airport, I'd really like to be reassured that this is
not a common occurrence.

Debbie



  #10  
Old November 11th 04, 06:03 PM
DM
external usenet poster
 
Posts: n/a
Default

Christopher Brian Colohan wrote:
DM writes:

Yesterday I saw a cargo jet (a major air express company) come to what
seemed like a dead stop in midair as it was making its ascent. After
about 20 - 30 seconds of hanging without dropping out of the sky, it
continued climbing and apparently did not crash. There's been nothing
about it in the local news but I've still been very concerned. Could
someone here explain how such a thing is possible?

Some details: the temperature was about 50 degrees F, the sky was
mostly clear, and the time was around 0645. I was traveling by car at
about 40 MPH on a street that is parallel to a regular flight
path. From this street it's common to see 3 or 4 planes per minute
either climbing or descending; the airport is about a mile or two away
from this particular street.



One detail you left out -- how windy was it? I'm going to guess it
was a really windy day. If the plane was taking off into a strong
headwind then it would not have to go nearly as fast (relative to the
ground) to stay in the air. The only thing the plane cares about is
how fast it is going relative to the wind (airspeed). You may have
seen a plane which was travelling at a much slower groundspeed than
you are used to seeing, and thought it was almost stopped as a result.

Also, if seems to be windy at ground level where you are, it may be
much windier once you get up above any trees/buildings/etc which only
slow the wind down.

Chris


interesting, but no, it wasn't particularly windy on the ground.

Debbie
 




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