to HSI or not to HSI

Irrelevant.


On Mon, 15 Nov 2004 20:58:13 -0500, "Richard Kaplan"
wrote:



wrote in message
news

It's a real simple concept, however, simpler really than "reverse
sensing" by a a lot. Anyone can learn it, and it takes the guesswork
out of the equation.

If we accept for the moment that your observation is correct, then how does
a pilot know when to activate the reverse-sense button on an autopilot?
Most autopilots seem to make the same "error" as most pilots in using the
"forward" vs. "reverse" sensing paradigm.


--------------------
Richard Kaplan, CFII

www.flyimc.com

On Tue, 16 Nov 2004 04:23:17 GMT, "Richard Hertz" no one@no one.com
wrote:


There is no reverse sensing. Look at a localizer approach - front or back
course. On the Nav head picture the left side of the indication to mean you
are in the blue sector (shaded) and the right side to mean you are in the
yellow (unshaded) sector. You just turn to intercept the center of the
course. There is no reverse, back, forward, etc. No math involved, no
switch, nothing, just consistent application of the same idea regardless of
Front course, back course, discourse, datcourse, ass course...



Precisely.

And you can get even more precision by using heading information
rather than the more generalized blue/yellow.

On Tue, 16 Nov 2004 04:26:26 GMT, Jose
wrote:

There is no reverse sensing. Look at a localizer approach - front or back
course. On the Nav head picture the left side of the indication to mean you
are in the blue sector (shaded) and the right side to mean you are in the
yellow (unshaded) sector. You just turn to intercept the center of the
course. There is no reverse, back, forward, etc. No math involved, no
switch, nothing, just consistent application of the same idea regardless of
Front course, back course, discourse, datcourse, ass course...

But the plane's steering wheel just goes left and right, not blue and yellow. And my charts are in black and white.

Jose


Your steering wheel can be used to turn to a precise heading as easily
as it can be used to simply turn right and left.

The first is more positive than the latter. Of course, it requires
that you first know what the heading is that does the job for the task
at hand.

I don't know about you, but I get uneasy flying in the couds with
pilots who only know that it's "somewhere over there on the right"
(where it may or may not be).

So what does any of this have to do with a pilot flying without an
autopilot?

The autopilot is programmed with all kinds of algorithms for flying
intercept headings.

I am quite sure an autopilot doesn't simply fly right towards a right
needle some undetermined amount, and then turn some more when the
needle doesn't move, as many pilots do who use your preferred method.




On Mon, 15 Nov 2004 23:29:57 -0500, "Richard Kaplan"
wrote:


"Richard Hertz" no one@no one.com wrote in message
et...


There is no reverse sensing. Look at a localizer approach - front or back

I say again... when using an autopilot to fly a localizer or localizer
backcourse approach, using your technique how does one intuitively know to
push the reverse-sense button so that the autopilot nav mode will operate
properly.

Many autopilots require the "reverse" or "backcourse" button to be pushed
when flying the frontcourse outbound or when flying the backcourse inbound.

You can argue all you want that there is "no such thing" as reverse sensing,
but the fact is that this button exists on many autopilots and such an
autopilot cannot fly a full localizer approach in nav mode without
activating the reverse button for part of the approach and deactivating the
button for part of the approach.


--------------------
Richard Kaplan, CFII

www.flyimc.com

Let's say you are about to fly a westbound localizer approach with a
procedure turn.

Approaching from the NNE, you cross the IAF and turn towards the east
for the procedure turn, ending up south of the course due to the
strong winds from the north/northwest and the duration of the turn .

The wind from the north/northwest, means you need to adjust to
re-intercept the approach course for the procedure turn outbound.

Just curious. What do you have your students do?


On Tue, 16 Nov 2004 11:53:42 GMT, "L. R. Diu Broff"
wrote:

wrote in :

I don't think my brain could handle that one. I did a lot of
instrument instructing many years ago, before HSIs appeared in light
aircraft. I thought then, and think now, of flying away from the CDI
needle when flying inbound on a back course.

I teach LOC BC just a little differently; I have had numerous trainees
remark on how simple it is. Just a little change in the way you think.

When flying the localizer back course (without an HSI), think: "I AM THE
NEEDLE. I need to fly toward the center of the CDI." This removes the
"reverse sensing" thought process and makes the whole thing just a little
more intuitive.

L. R. Du Broff
CFII (gold seal)

On Mon, 15 Nov 2004 19:19:04 -0500, Matt Whiting
wrote:

wrote:

On Mon, 15 Nov 2004 06:32:32 -0800, wrote:


Am I missing something in this thread? With an HSI if you set the front course
bearing on the OBS, you fly inbound on a back course approach into the needle
just as you do with the front course.




Yep.

Exactly what you do with a DG/OBS, if you create a mental HSI by
superimposing the DG onto the OBS, or vice versa.

An HSI does not sense anything any differently. It combines two
instruments for ease of interpretation. The same thing can be done
mentally, if you want to save yourself $8000 or so.

If you set the OBS to the inbound course on a back course, and fly
headings that are on the CDI side of the OBS ring, you are doing what
the HSI "tells" you to do.

True, but the HSI makes it much easier.


Matt

True, but the HSI makes it much more expensive.

"Jose" wrote in message
om...
There is no reverse sensing. Look at a localizer approach - front or
back course. On the Nav head picture the left side of the indication to
mean you are in the blue sector (shaded) and the right side to mean you
are in the yellow (unshaded) sector. You just turn to intercept the
center of the course. There is no reverse, back, forward, etc. No math
involved, no switch, nothing, just consistent application of the same
idea regardless of Front course, back course, discourse, datcourse, ass
course...

But the plane's steering wheel just goes left and right, not blue and
yellow. And my charts are in black and white.

Perhaps instrument flying is not for you. I am truly sorry about your
condition. Sorry to have wasted your time.


Jose
--
Freedom. It seemed like a good idea at the time.
for Email, make the obvious change in the address.

"Richard Hertz" no one@no one.com wrote
This is of course correct - provided you can get the student to do
mental math on the approach. Of course to someone brought up on the
ADF, that's not a big deal - if you fly ADF approaches, every approach
requires mental math all the time.

What mental math? You look at the needle, determine what sector it is in,
then look at the chart and matchi it up.

And then you have to check your heading, and figure out the proper
heading to intercept, turn to that heading, and fly it. That's the
mental math. Sure, it's just addition/subtraction with 3 digit
numbers - but most people can't do that quickly. They get confused.

I don't know if I would go that far. For those that use them it is a
wonderful tool. For those that do not it is useless.

Yes, but most don't use it. I do, of course - my home field only has
GPS and NDB approaches, and I don't have IFR GPS. And I do teach ADF
approaches, in actual, to minimums. But I'm an anachronism. Most
flight schools are removing the ADF from the trainers so as not to
have to teach the ADF.

It may not be cheaper than installing a switch. Instruction also
costs money, if nothing else than in aircraft operation time. In the
higher end aircraft, it may not be cheaper than buying HSI's.

Agreed, but my point was that if the training had been correct the first
time around it would all be avoided.

And my point is that if you're training someone who can't add/subtract
three digit numbers in his head, the training is going to take a long
time.

And you think that people would remember to flip the switch?

They only have to remember it ONCE - upon starting the approach.

As you pointed out earier I seem to have started a religious war and I am
sorry for it.

Why? It's on topic and relevant, and everyone is being civil.

I have not been on this group long enough to have seen this one before.

Nor I. It was just obviously the sort of thing that starts one here.

I do, and I lament it terribly. I own many rental properties and pay taxes
for many school districts and I am certainly not getting my "money's worth"
from our local governments. I tutored some students recently and was
appalled at the curriculum and the text books.

Well, what I'm trying to explain to you is that the process you refer
to as simple actually involves mental math - geometry to be exact.
You either have to visualize angles or do three digit
addition/subtraction. The average graduate of the modern educational
system can't do either one quickly, because the necessary skills,
concepts, and drill don't happen early enough. Algebra isn't a
3rd-4th grade subject as it once was (as late as the 1970's in the
Soviet Union) but a High School subject. By then, it's not too late
to get the concepts across (to most) but it is too late to get the
speed.

Michael

wrote:

On Mon, 15 Nov 2004 19:19:04 -0500, Matt Whiting
wrote:


wrote:


On Mon, 15 Nov 2004 06:32:32 -0800, wrote:



Am I missing something in this thread? With an HSI if you set the front course
bearing on the OBS, you fly inbound on a back course approach into the needle
just as you do with the front course.




Yep.

Exactly what you do with a DG/OBS, if you create a mental HSI by
superimposing the DG onto the OBS, or vice versa.

An HSI does not sense anything any differently. It combines two
instruments for ease of interpretation. The same thing can be done
mentally, if you want to save yourself $8000 or so.

If you set the OBS to the inbound course on a back course, and fly
headings that are on the CDI side of the OBS ring, you are doing what
the HSI "tells" you to do.

True, but the HSI makes it much easier.


Matt


True, but the HSI makes it much more expensive.


The good things in life aren't free! :-)

Once can argue that a VOR is more expensive than dead/ded reckoning also...


Matt

"Michael" wrote in message
om...
"Richard Hertz" no one@no one.com wrote
This is of course correct - provided you can get the student to do
mental math on the approach. Of course to someone brought up on the
ADF, that's not a big deal - if you fly ADF approaches, every approach
requires mental math all the time.

What mental math? You look at the needle, determine what sector it is
in,
then look at the chart and matchi it up.

And then you have to check your heading, and figure out the proper
heading to intercept, turn to that heading, and fly it. That's the
mental math. Sure, it's just addition/subtraction with 3 digit
numbers - but most people can't do that quickly. They get confused.

I don't see how the sector method neccesitates doing math where "yours" (the
left right) does not. (However, I would argue that flying a heading is the
proper way to fly regardless, otherwise you have no idea what is going on.
Chasing needles is worthless and prone to cause significant problems later
on.)

You can figure out "left" or "right" by looking at the chart - it is one
extra glance at the chart compared to the more popular left/right method and
no math is involved.


I don't know if I would go that far. For those that use them it is a
wonderful tool. For those that do not it is useless.

Yes, but most don't use it. I do, of course - my home field only has
GPS and NDB approaches, and I don't have IFR GPS. And I do teach ADF
approaches, in actual, to minimums. But I'm an anachronism. Most
flight schools are removing the ADF from the trainers so as not to
have to teach the ADF.

My instructor was an anachronism as well. He loathes the pretty maps and
pictures on the display. Thinks it is killing all understanding of IFR
flying.


It may not be cheaper than installing a switch. Instruction also
costs money, if nothing else than in aircraft operation time. In the
higher end aircraft, it may not be cheaper than buying HSI's.

Agreed, but my point was that if the training had been correct the first
time around it would all be avoided.

And my point is that if you're training someone who can't add/subtract
three digit numbers in his head, the training is going to take a long
time.

I suppose, I am not a CFII. I have no idea what to say to that - (however,
I am not sure the method I advocate requires doing math - there is a way to
find "left/right" by looking at a chart) So how do these folks figure out
intercept angles or other such stuff? Surely you have to prepare them to be
ready to intercept airways and courses, etc. (There is also the timed
turns) I am astounded that this is the hard part and not those other issues
for people who can't do math. I cringe thinking about how they must start
smoking out their heads when they have to come up with wind corrections or
other stuff.


And you think that people would remember to flip the switch?

They only have to remember it ONCE - upon starting the approach.

But what if they do not? The problem can be reduced to the same thing - if
there is a possibility of forgetting it any time during the approach without
the switch, surely there is a possibility of forgetting it for the entire
approach. it is likely they will realize something is wrong when the needle
goes crazy according to their misunderstanding of the situation.


As you pointed out earier I seem to have started a religious war and I am
sorry for it.

Why? It's on topic and relevant, and everyone is being civil.

I have not been on this group long enough to have seen this one before.

Nor I. It was just obviously the sort of thing that starts one here.

I do, and I lament it terribly. I own many rental properties and pay
taxes
for many school districts and I am certainly not getting my "money's
worth"
from our local governments. I tutored some students recently and was
appalled at the curriculum and the text books.

Well, what I'm trying to explain to you is that the process you refer
to as simple actually involves mental math - geometry to be exact.
You either have to visualize angles or do three digit
addition/subtraction. The average graduate of the modern educational
system can't do either one quickly, because the necessary skills,
concepts, and drill don't happen early enough. Algebra isn't a
3rd-4th grade subject as it once was (as late as the 1970's in the
Soviet Union) but a High School subject. By then, it's not too late
to get the concepts across (to most) but it is too late to get the
speed.

I don't even want to discuss the horrors I see constantly with the local
"education" system.


Michael