Help estimating altitude without altimeter?

On Oct 27, 4:47*pm, Bruce Hoult wrote:
On Oct 28, 3:13*am, Andy wrote:

For the circling over the airport problem you can get some indication
of altitude by looking at the path the wingtip traces on the ground
from a known bank angle. *Above a certain height the path will be
counter to the turning direction, below that height it will be in the
same direction. Do the math to convince yourself.

I guess you didn't do the math yourself :-)

The height at which the change from wingtip-goes-backwards to wingtip-
goes-forwards occurs is too low to be used for normal circuit entry.
At 40 knots it's only 140 ft, and at 60 knots it is about 320 ft. If
you want to use this to judge a 700 ft circuit entry then you'll have
to be flying at 90 knots.

Thanks - I didn't do the math. I usually do the math but was feeling
lazy. :-(

I would argue that pattern traced by the wingtip changes even if it
doesn't reverse direction at higher elevations - the reverse circle
gets bigger and bigger as you go higher.

I generally enter the pattern at about 75-80 knots. You could
certainly do a circle at 90 knots if you really needed to see the
wingtip rotate the other way and had no idea how high you were - at
that speed your energy would take you back up to 1000' AGL.

The general point is that all the angular rates versus ground
references change as you get closer to the ground and you should be
aware of them. Turning flight likely gives you more cues than flying
straight ahead.

9B

On Oct 28, 2:25*am, Surfer! wrote:
In message , ZZ
writesTom:

How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern,

Snip

I would say it's 'how the reference point looks'. *We can have a
reference point anywhere, but if landing out we won't be seeing our own
familiar airfield. *Is the reference point technique taught in the US?

--
Surfer!
Email to: ramwater at uk2 dot net

The best 'reference point' is the intended landing surface. Anything
else is likely to be misleading. Even telephone poles are not all the
same height or spacing.

There are lots of clues to height which taken together can give a
pretty accurate estimate. Pilots may not even be aware of all the
clues they're using, just that with increasing experience, their
estimates begin to work.

One old skydiver clue is that when people stop looking like ants and
start looking like people, it's time to pull. That's about 2000' AGL
and not a bad height to be over the landing area looking for wind and
obstacles.

On Oct 28, 1:08*pm, bildan wrote:
On Oct 28, 2:25*am, Surfer! wrote:





In message , ZZ
writesTom:

How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern,

Snip

I would say it's 'how the reference point looks'. *We can have a
reference point anywhere, but if landing out we won't be seeing our own
familiar airfield. *Is the reference point technique taught in the US?

--
Surfer!
Email to: ramwater at uk2 dot net

The best 'reference point' is the intended landing surface. *Anything
else is likely to be misleading. *Even telephone poles are not all the
same height or spacing.

There are lots of clues to height which taken together can give a
pretty accurate estimate. *Pilots may not even be aware of all the
clues they're using, just that with increasing experience, their
estimates begin to work.

One old skydiver clue is that when people stop looking like ants and
start looking like people, it's time to pull. *That's about 2000' AGL
and not a bad height to be over the landing area looking for wind and
obstacles.

Anyone try using the wing vs. runway relationship? In the Skyhawk I
was taught to keep the runway 1/2 to 2/3 up the strut, correcting for
wind. I know that this would lead to flying an ever closer pattern as
you descend, but could it not be used to get you in the groove up to
abeam the touchdown point? Then it would be a matter of TLAR from
there to touchdown.

I offer this as a question, not a suggestion. I've done very little
flying away from the home field, and I live in a very flat state.

The reference "point" assuming that you can see it, is the the runway or
more specifically, the TDZ.

Paul
ZZ



Surfer! wrote:
In message , ZZ
writes
Tom:

How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern,
Snip

I would say it's 'how the reference point looks'. We can have a
reference point anywhere, but if landing out we won't be seeing our own
familiar airfield. Is the reference point technique taught in the US?

If you can only see whole woods or forests you are quite high. If you
can see individual trees you are getting a bit low. If you can see the
branches you are very low, If you can see the leaves...don't even
ask!

If you can see your reference point, estimate your distance away from
it and judge the angle (should be about 15 degrees), you should be
able to land accurately with a bit of practice, without reference to
the altimeter. Remember that the altimeter is pretty useless when
outlanding at a field of unknown elevation.

Derek Copeland (UK gliding instructor)


On Oct 29, 2:52*am, ZZ wrote:
The reference "point" assuming that you can see it, is the the runway or
more specifically, the TDZ.

Paul
ZZ



Surfer! wrote:
In message , ZZ
writes
Tom:

How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern,
Snip

I would say it's 'how the reference point looks'. *We can have a
reference point anywhere, but if landing out we won't be seeing our own
familiar airfield. *Is the reference point technique taught in the US?- Hide quoted text -

- Show quoted text -

I knew that my original comment was going to start fist fights. But it's
winter in the northern hemisphere and we need something to do.

We have a student pilot who says that he is having trouble estimating
his altitude in the pattern. So instead shall we will advise him to
estimate angles? What this pilot really lacks is experience. What I
contend is that INITIALLY forcing him to see many "ideal" patterns,
i.e. repetition, is an important step in learning what a "normal"
pattern looks like and when the pattern is poorly flown, he will then
recognize it right away. Certainly, angles are part of what is being
learned but quantifying the angle is not required to learn. Of course
lift/sink, wind, low arrivals at the field, rope breaks, rock-offs, last
minute runway changes and buffoonery from the guy in the pattern in
front of him will force him to modify his pattern. My students are
trained to fly all of these problems without altimeter reference. But
initially, I begin by giving them a solid grounding in what "normal"
LOOKS LIKE.

As for our student who is trying to estimate his altitude, keep flying.
It will come all together.

Paul Corbett
ZZ








delboy wrote:
If you can only see whole woods or forests you are quite high. If you
can see individual trees you are getting a bit low. If you can see the
branches you are very low, If you can see the leaves...don't even
ask!

If you can see your reference point, estimate your distance away from
it and judge the angle (should be about 15 degrees), you should be
able to land accurately with a bit of practice, without reference to
the altimeter. Remember that the altimeter is pretty useless when







outlanding at a field of unknown elevation.

Derek Copeland (UK gliding instructor)


On Oct 29, 2:52 am, ZZ wrote:
The reference "point" assuming that you can see it, is the the runway or
more specifically, the TDZ.

Paul
ZZ



Surfer! wrote:
In message , ZZ
writes
Tom:
How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern,
Snip
I would say it's 'how the reference point looks'. We can have a
reference point anywhere, but if landing out we won't be seeing our own
familiar airfield. Is the reference point technique taught in the US?- Hide quoted text -
- Show quoted text -

If you can estimate the distance and judge the angle, this fixes the
height - this is simple trigonometry.

In the UK we teach an exercise called the zig-zag circuit where the
instructor demonstrates a circuit starting at the right high key
distance, height and angle to the reference point, but allows the
gider to drift in so the low key point is reached at about the right
height, but much too close in. Thus the student can see that the
angle looks much too steep (the impression given is that you are much
too high, but you are not). Then you move back out until the angle
looks right and complete the circuit normally.

I do not disagree with ZZ that regular experience of what a circuit
should look like is a necessary part of training. Also learning to
judge what items on the ground, such as trees, vehicles and houses
look like from different heights.

Derek Copeland

P.S This is posted from Google Groups, as I can't seem to access
r.a.s. directly from gp.net. Is there a problem with my email address
or UK postings Andy?

On Oct 27, 11:07*pm, ZZ wrote:
Tom:

How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern, you are experimenting and this will
work eventually. I have found a way to accelerate this process a bit. I
have my students fly their patterns at precise altitudes at specific
points in the pattern. And I insist on precise airpeed control as well..
This accomplishes two things..precise pattern flying...the same picture
every time and this "groove becomes epoxied into their brain more
quickly. Then, when I take their altimeter away and change runways, they
have no problems repeating the maneuver properly. Now I am all too
familiar with the argument against this technique i.e. what are they
going to do if they are landing at a field without the familiar
landmarks? It's that profile to the runway that they are really learning
by repeating the same profile time after time.

I have about 31 patterns (including my solo flights). What you
describe is exactly how I was taught to do my patterns. I enter the
pattern at 1000' AGL, then I am at 800' AGL when I pass my aim point
(this will be the my flare point not TD point), make my turn to base
at 600' AGL, and my turn to final at 400' AGL.

Once I get into the down wind leg at the correct altitude the rest is
no problem without the altimeter. It's estimating when to enter the
pattern without altimeter which I find difficult.

I'll try to pay more attention to how things look at that point and
hopefully it'll get easier.

-tom

Anyone try using the wing vs. runway relationship? In the Skyhawk I
was taught to keep the runway 1/2 to 2/3 up the strut, correcting for
wind. I know that this would lead to flying an ever closer pattern as
you descend, but could it not be used to get you in the groove up to
abeam the touchdown point? Then it would be a matter of TLAR from
there to touchdown.

I offer this as a question, not a suggestion. I've done very little
flying away from the home field, and I live in a very flat state.

This is sort of how I ultimately did it... when my aimpoint was at 9
o'clock, it appeared about 1/3 of the way down from the wing tip, just
under the air brake. This was about 800'.

-tom

On Oct 30, 10:47*am, tstock wrote:
On Oct 27, 11:07*pm, ZZ wrote:



Tom:

How many patterns have you flown since you began your training? Until
you develop a clear picture in your mind of how your airfield looks at
different points in the pattern, you are experimenting and this will
work eventually. I have found a way to accelerate this process a bit. I
have my students fly their patterns at precise altitudes at specific
points in the pattern. And I insist on precise airpeed control as well...
This accomplishes two things..precise pattern flying...the same picture
every time and this "groove becomes epoxied into their brain more
quickly. Then, when I take their altimeter away and change runways, they
have no problems repeating the maneuver properly. Now I am all too
familiar with the argument against this technique i.e. what are they
going to do if they are landing at a field without the familiar
landmarks? It's that profile to the runway that they are really learning
by repeating the same profile time after time.

I have about 31 patterns (including my solo flights). *What you
describe is exactly how I was taught to do my patterns. *I enter the
pattern at 1000' AGL, then I am at 800' AGL when I pass my aim point
(this will be the my flare point not TD point), make my turn to base
at 600' AGL, and my turn to final at 400' AGL.

Once I get into the down wind leg at the correct altitude the rest is
no problem without the altimeter. *It's estimating when to enter the
pattern without altimeter which I find difficult.

I'll try to pay more attention to how things look at that point and
hopefully it'll get easier.

-tom

Hey, fst learner! I actually can't tell you what altitude I do the
turns at,
because I never look at the altimeter once past the aimpoint on
downwind leg (at 600 feet). When I was first learning to fly we used
the Tom
Knauff textbook, which had as the last entry on the landing
checklist "ignore altimeter". I fly and teach the pattern judgement
mainly based on seeing the desired final approach glideslope while
you are on downwind leg. It's fairly easy to turn base so you hit
that
slope, plus you have your mind two legs ahead of where the airplane
is instead of a leg or two behind.

-- Matt