NDB Holds

Thanks guys for the response. What I suppose I am asking if how do you work
out the times (pre-planning) of the hold. I.e if you know the wind direction
and speed for the hold, I've worked out the single drift and in my notes it
says to work out the timings use 75% of the head / tail wind factor.

This is where I get stuck. How do you work that out??



"Sam Spade" wrote in message
...
Mark Hansen wrote:

On 10/27/06 14:35, Alan Burke wrote:

Hi,

I'm studying for my IR and having some trouble in calculating the
outbound times. Has anyone got any easy way of calculating the times.

Keep in mind, as you progress with this, that the "rule" is to not exceed
one minute inbound to the NDB.

In article ,
"Alan Burke" wrote:

Thanks guys for the response. What I suppose I am asking if how do you work
out the times (pre-planning) of the hold. I.e if you know the wind direction
and speed for the hold, I've worked out the single drift and in my notes it
says to work out the timings use 75% of the head / tail wind factor.

This is where I get stuck. How do you work that out??

Don't try to "work it out". Your primary job is to fly the airplane, not
work out complex geometry problems.

As you're approaching the hold, take a WAG (Wild Assed Guess) at wind
strength. In most common trainers, you'll be holding at about 90 kts. A
really big headwind component on your outbound leg would be 30 kts, making
your outbound groundspeed 60, and your inbound groundspeed 120 (double your
outbound).

So, that's pretty much an upper limit, and gives you your first WAG: with a
really honking headwind outbound, fly the outbound leg for 2 minutes.
Estimate down from the with a moderate headwind outbound, try 1.5
minutes. With little or no wind, try 1 minute. With a moderate tailwind
outbound, try 50 seconds, and with a really honking tailwind outbound, try
40 seconds. If you're trying to get things any more accurate than that,
you're doing way too much work.

It's better to fly your first outbound leg a little bit long rather than a
little bit short. If you under-estimate how long to fly outbound, by the
time you complete your inbound turn, you can be almost on top of the NDB
and not have enough time to re-intercept the inbound bearing before you
reach station passage. When that happens, you tend to just keep getting
more and more confused and lost.

But, the real way to do NBD holds is to tear that piece of crap ADF out of
the panel and train in a GPS-equipped airplane. If your school doesn't
have GPS in their trainers, find another school.

Alan,

my notes it
says to work out the timings use 75% of the head / tail wind factor.


Hmm. Why not 100 percent? The way I would do it is to figure out the
percentage the head/tail wind is of my IAS (TAS, if you want to get
precise). Then, I would correct 1 minute by that percentage. From your
notes, your supposed to take 75 percent of that percentage.

In reality, this takes way too much brain power away from controlling
the aircraft. Make intelligent guesses. E.g. your holding speed is 90
knots, your wind component is an estimated 10 knots, so you try a 10
seconds correction.

--
Thomas Borchert (EDDH)

Thomas Borchert wrote:
Alan,


my notes it
says to work out the timings use 75% of the head / tail wind factor.



Hmm. Why not 100 percent? The way I would do it is to figure out the
percentage the head/tail wind is of my IAS (TAS, if you want to get
precise). Then, I would correct 1 minute by that percentage. From your
notes, your supposed to take 75 percent of that percentage.

In reality, this takes way too much brain power away from controlling
the aircraft. Make intelligent guesses. E.g. your holding speed is 90
knots, your wind component is an estimated 10 knots, so you try a 10
seconds correction.


At 90 knots it all is just b.s. to try to placate some anal instructor
or check airperson. The holding pattern protected airspace is designed
for a jet aircraft.

At 90 knots it all is just b.s. to try to placate some anal instructor or check airperson. The holding pattern protected airspace is designed for a jet aircraft.

I wouldn't go that far. We are also building good habits and attitudes
for the future. One day we may be flying jet aircraft, who knows? The
attitudes you start out with are likely to be the attitudes you end up
with, and the skills you learn from day one are the ones that come back
to you in an emergency.

However, yes, there is plenty of room in the hold for a spam can.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

Jose wrote:
At 90 knots it all is just b.s. to try to placate some anal instructor
or check airperson. The holding pattern protected airspace is
designed for a jet aircraft.


I wouldn't go that far. We are also building good habits and attitudes
for the future. One day we may be flying jet aircraft, who knows? The
attitudes you start out with are likely to be the attitudes you end up
with, and the skills you learn from day one are the ones that come back
to you in an emergency.

I have posted almost exactly the same comments here in the past. Of
course, you are correct. The "recommended" entries are really mandatory
for jet aircraft operating at the max permitted speeds. And, so forth.

However, yes, there is plenty of room in the hold for a spam can.

Exactly.

Jose wrote:
At 90 knots it all is just b.s. to try to placate some anal instructor or
check airperson. The holding pattern protected airspace is designed for a
jet aircraft.

I wouldn't go that far. We are also building good habits and attitudes
for the future.

Right. And a good attitude is to not get bogged down in minutia like
calculating outbound leg times for NDB holds when there's more important
stuff to be thinking about.

What's the weather doing? What's my fuel situation, i.e. how long can I
let ATC park me here before I need to head to my alternate? What is my
best alternate given the current situation? Can I review the approach
plate one more time to make sure I really understand the procedure.

Roy Smith wrote:
Jose wrote:

At 90 knots it all is just b.s. to try to placate some anal instructor or
check airperson. The holding pattern protected airspace is designed for a
jet aircraft.

I wouldn't go that far. We are also building good habits and attitudes
for the future.


Right. And a good attitude is to not get bogged down in minutia like
calculating outbound leg times for NDB holds when there's more important
stuff to be thinking about.

What's the weather doing? What's my fuel situation, i.e. how long can I
let ATC park me here before I need to head to my alternate? What is my
best alternate given the current situation? Can I review the approach
plate one more time to make sure I really understand the procedure.

And, what are the odds of having to hold at an NDB in the 21st Century?

In article , Sam Spade
wrote:

And, what are the odds of having to hold at an NDB in the 21st Century?

Essentially zero. But, if your instructor (or flight school) is dumb
enough to send you for an instrument checkride in an airplane equipped with
an ADF, you may be called upon to demonstrate one. Which means they need
to train you to be able to perform one. Which, of course, is a huge waste
of your time and money, since it's a skill you will never use again after
the checkride.

Which is why, earlier in this thread, I said:

But, the real way to do NBD holds is to tear that piece of crap ADF out of
the panel and train in a GPS-equipped airplane. If your school doesn't
have GPS in their trainers, find another school.

On Sat, 28 Oct 2006 12:12:01 -0700, Sam Spade wrote:

And, what are the odds of having to hold at an NDB in the 21st Centur

On a few occasions, I've held at an NDB, but only one of those occasions
was in the 21st century, and not in the past few years since I've had a
GPS.

I held at the EPM NDB for 1/2 hour or so waiting for weather to improve,
before we had a GPS approach.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)