Question to Mxmanic

Mxsmanic wrote in
:

Don't you have to descend to catch the wake? Downwash should be moving
downward at a few knots and IIRC the vortices do as well, so after two
minutes at, say, 12 knots, the turbulence would be almost 2500 feet
below you, if you are staying at altitude. I don't see how you could
run into it.

I'm not a physicist, but I suspect your calculations are missing several
factors, including (but not limited to) some that I can point out:

1) At a 45 degree bank, the wings are not actually pointed directly down.

2) In the typical trainer plane flying 100 knots, a 45 degree bank turn
will take far less than 2 minutes to go 360 degrees.

3) Wind can blow the wake in any number of directions, including up, and
including into the path of the 360 degree turn.

The bottom line is that the Practical Test Standards call for pilots to
perform a manuever called a Steep Turn of 360 degrees at a bank angle of 45
degrees. Every certificated pilot practices this, and demonstrates it to an
examiner, and frequently demonstrates it again during his or her Biannual
Flight Review.

Do you think it is more likely that the pilots on this newsgroup who
express that they have flown through their own wake while performing this
manuever are just lying to you?

Or perhaps you have miscalculated or omitted something from your
calculations.

"Mxsmanic" wrote in message
...
swag writes:

This is actually a maneuver that's demonstrated and practiced very
early in flight training, so I'm sure all pilots and student pilots
have experienced this. But your calculations are fairly correnct--a 2
minute turn won't cut it. It's usually demonstrated with a 60 degree
bank turn. I'm not sure of the timing, but i'd guess 30 sec or less.

Don't you have to descend to catch the wake? Downwash should be moving
downward at a few knots and IIRC the vortices do as well, so after two
minutes
at, say, 12 knots, the turbulence would be almost 2500 feet below you, if
you
are staying at altitude. I don't see how you could run into it.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Wakes are complex in their action. Consistently cutting your own wake in
360s and figure 8s is a mark of good technique--and the altimeter reading
will remain unchanged.

Since they are covered extensively in both flight and ground instruction,
there seems little need here.

Peter

swag writes:

This is actually a maneuver that's demonstrated and practiced very
early in flight training, so I'm sure all pilots and student pilots
have experienced this. But your calculations are fairly correnct--a 2
minute turn won't cut it. It's usually demonstrated with a 60 degree
bank turn. I'm not sure of the timing, but i'd guess 30 sec or less.

Sorry, I didn't notice the 60-degree part. Sixty degrees would be 2.7 Gs,
which seems high for a GA aircraft. If I'm not mistaken, this would allow a
360-degree turn in about one minute at 100 kts. Still, the wake would be a
thousand feet lower or so by then (assuming a 12-kt downwash).

--
Transpose mxsmanic and gmail to reach me by e-mail.

"Mxsmanic" wrote in message
...
swag writes:

This is actually a maneuver that's demonstrated and practiced very
early in flight training, so I'm sure all pilots and student pilots
have experienced this. But your calculations are fairly correnct--a 2
minute turn won't cut it. It's usually demonstrated with a 60 degree
bank turn. I'm not sure of the timing, but i'd guess 30 sec or less.

Sorry, I didn't notice the 60-degree part. Sixty degrees would be 2.7 Gs,
which seems high for a GA aircraft. If I'm not mistaken, this would allow
a
360-degree turn in about one minute at 100 kts. Still, the wake would be
a
thousand feet lower or so by then (assuming a 12-kt downwash).


Your calculations are as insane as you are, guess again.
What you are MISSING is well beyond the scope this newsgroup, much less this
topic.
Sixty degrees turns are part of routine PPL training, without a parachute.
Check the regs you so often quote with implied authority.
Finding your own wake turbulence while doing 60/360s happens every day, and
is most often demonstrated by every CFI.
Descending 360 turns are executed routinely by pilots needing to descend
without leaving an area, such as descending to land after crossing high
mountains.

You demonstrate daily that you are incompetent to comprehend the answers to
the questions you pose, and regardless of your motives, based on your own
lack of experience, you serve no more purpose here than a common troll.

Get a life,,, or make time and money for a few measly flight hours.

Mxsmanic,

Sixty degrees would be 2.7 Gs,


GO AWAY!

--
Thomas Borchert (EDDH)

Sorry, I didn't notice the 60-degree part. Sixty degrees would be 2.7 Gs,

Incorrect statement. Sixty degrees would be 2 Gs.

Mxsmanic wrote:
Sorry, I didn't notice the 60-degree part. Sixty degrees would be 2.7 Gs,

nope, at 60 degrees you got yourself 2Gs; about 1.4Gs at 45 degrees.

So... you might want to go over your calculations again.

--Sylvain

"Mxsmanic" wrote in message
...
swag writes:

This is actually a maneuver that's demonstrated and practiced very
early in flight training, so I'm sure all pilots and student pilots
have experienced this. But your calculations are fairly correnct--a 2
minute turn won't cut it. It's usually demonstrated with a 60 degree
bank turn. I'm not sure of the timing, but i'd guess 30 sec or less.

Sorry, I didn't notice the 60-degree part. Sixty degrees would be 2.7 Gs,
which seems high for a GA aircraft. If I'm not mistaken, this would allow
a
360-degree turn in about one minute at 100 kts. Still, the wake would be
a
thousand feet lower or so by then (assuming a 12-kt downwash).

--
Transpose mxsmanic and gmail to reach me by e-mail.

2.00 Gs

In rec.aviation.piloting swag wrote:
This is actually a maneuver that's demonstrated and practiced very
early in flight training, so I'm sure all pilots and student pilots
have experienced this. But your calculations are fairly correnct--a 2
minute turn won't cut it. It's usually demonstrated with a 60 degree
bank turn. I'm not sure of the timing, but i'd guess 30 sec or less.

It is 45 degrees +/- 5 for private, 50 +/- 5 for commercial.

--
Jim Pennino

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"Mxsmanic" wrote ...

From my back-of-envelope calculations, if it's a two-minute turn, the
downwash
and vortices would have descended by some 2000 feet or so by the time you
close the circle (depending on various factors). I'm surprised that there
would be anything to feel if you are maintaining the same altitude, which
is
why I didn't consider this. However, if it has actually happened to you,
I'll
have to review my calculations.

Tip vortices is not the only form of turbulence behind an aircraft. And an
airliner on approach has a different type of wake than a trainer at
altitude.

Anyway, while it might be interesting in real life, it would be
horrifically
CPU-intensive to simulate, since it would require modeling of large chunks
of
air away from the aircraft, which is as compute-bound as weather
reporting.

Indeed, modeling any sort of wake turbulence would be this way, unless the
simulation were canned and provided as a couple of fixed scenarios that
wouldn't require calculation of air movements. But then you have to
wonder if
it would be worthwhile, either, since it's a really bad idea to fly
through
another aircraft's wake turbulence. If it's mild there's not much to
simulate; if it's heavy it's too dangerous to approach.

The best value of a good simulator is that it enables training of situations
that would be unsafe to do in a real aircraft.Flying into wake turbulence is
a good example.