More newbie Qs

Christopher Brian Colohan wrote:

I managed to pick up an outdated
copy of the Jeppesen Private Pilot textbook for $5. This book would
answer every one of your questions, and more, with much more detail
and better pictures than you are likely to find on this newsgroup or
on the web.

Yep. That's really what you should do, Rama. That's an excellent book.

George Patterson
The desire for safety stands against every great and noble enterprise.

In article .com,
"Ramapriya" wrote:

I wish you all a very cheery 2005. You really are a nice set of guys
here (those branding me a terrorist notwithstanding), mostly patient
even at clarifying elementary stuff

Some more Qs, if you don't mind.

Since I have nothing better to do at the moment...

1. How does a pilot get to know the distance to the airport that he has
to land in, so that he plans his descent accordingly, in planes that
don't have an onboard computer? Maps I know would give the distance
between two fixed points, but how does he keep track of distance
covered in flight and that sort of thing?

It's a learned skill, a combination of keeping track of where you are
relative to the ground and using charts, and learning to judge distances
visually in the air.

To inquire ground stations
such info would be embarrassing, I guess

A little perhaps, but pilots get lost regularly. It's much better to be
a little embarrassed than totally lost.

2. What exactly is a VOR? Sounds like it's a constant all-direction
radio transmission from a fixed point

That's more or less correct. There are actually two different kinds of
such ground-based transmitters: VORs and NDBs. As others have mentioned
in this thread, Google is your friend.

on the airport

That's not correct. Some VOR transmitters are at airports. Others
aren't.

3. If a pilot needs to land at an airport that doesn't have a control
tower, how does he figure its elevation so that he may plan his
descent?

He consults a chart or an airport directory.

4. When a pilot says, "Give me a vector", what does he actually mean?

He's asking air traffic control to tell him which direction to fly.
(It's a less embarrassing way of saying, "I'm lost".)

5. When pilots use miles in conversations, does it mean the miles we
normally use, or is it always nautical miles?

It's supposed to be always nautical, but distance estimates are often
wrong by more than 10%, which is the different between nautical and
statute miles, so it often doesn't really matter.

6. The difference between airspeed and groundspeed is that airspeed is
the net of the plane's speed and opposing windspeed, while groundspeed
is just the plane's speed. Right?

Not quite. There's no such thing as "just the plane's speed." There is
only the plane's speed with respect to other things. Airspeed is the
plane's speed with respect to the air. Ground speed is the plane's
speed with respect to the ground.

7. What is "density altitude"

It's a way of expressing the air's capacity for supporting the
airplane's weight taking into account the effect of both altitude and
temperature. When the air gets hot it expands and effectively gets
"thinner". Aircraft performance figures assume a standard temperature.
When the air is hotter than that temperature you take that into account
by figuring out what the "effective" altitude is, that is, the altitude
which, at standard temperature, has the same capacity for supporting the
airplane's weight at whatever the temperature happens to actually be.

, and how to compute it?

It's usually done by looking it up in a table. There's a formula, but
few people actually use it.

If I'm not wrong,
its use is to plan the length of takeoff roll and angle of climb.

Yep.

rg

5. When pilots use miles in conversations, does it mean the miles we
normally use, or is it always nautical miles?

It's supposed to be always nautical, but distance estimates are often
wrong by more than 10%, which is the different between nautical and
statute miles, so it often doesn't really matter.

how can that be.. a distance is a distance.. who said anything about
"estimates"..
If I measure 10nm then it is 10nm.. if my DME says I'm x miles from station
y, then that's where I am... there is no 10% error..

BT

In article SL5Bd.2351$232.844@fed1read05,
"BTIZ" wrote:

5. When pilots use miles in conversations, does it mean the miles we
normally use, or is it always nautical miles?

It's supposed to be always nautical, but distance estimates are often
wrong by more than 10%, which is the different between nautical and
statute miles, so it often doesn't really matter.

how can that be.. a distance is a distance.. who said anything about
"estimates"..
If I measure 10nm then it is 10nm.. if my DME says I'm x miles from station
y, then that's where I am... there is no 10% error..

Read the question again: "When pilots use miles in conversations..."
When a pilot says, "Five miles from the field" the actual physical
distance is never exactly five miles.

Even when your DME says x miles from station y that is *not* where you
are. At best, it is the slant-line distance, and at worst it's a
completely arbitrary number because your DME could be kerfliggered.
Furthermore, a VORTAC is more or less a point, but an airport isn't. A
typical airport is many tenths of miles (of either flavor) long/wide.
You'd have to pick an arbitrary point on the field and measure your
distance to that. What do you pick? The tower? What if there is no
tower? The middle of the runway? What if there's more than one runway?
The end of the runway? Which end?

So you see, the actual physical distance from your airplane to an
airport is not even well defined. So when a pilot says "I'm five miles
from the field" what he really means is "I'm somewhere in the vicinity
of five miles" at which point it doesn't much matter what kind of miles
are meant.

rg

in any case.... the reference is always to nautical.. in this day and age..

BT

"Ron Garret" wrote in message
...
In article SL5Bd.2351$232.844@fed1read05,
"BTIZ" wrote:

5. When pilots use miles in conversations, does it mean the miles we
normally use, or is it always nautical miles?

It's supposed to be always nautical, but distance estimates are often
wrong by more than 10%, which is the different between nautical and
statute miles, so it often doesn't really matter.

how can that be.. a distance is a distance.. who said anything about
"estimates"..
If I measure 10nm then it is 10nm.. if my DME says I'm x miles from
station
y, then that's where I am... there is no 10% error..

Read the question again: "When pilots use miles in conversations..."
When a pilot says, "Five miles from the field" the actual physical
distance is never exactly five miles.

Even when your DME says x miles from station y that is *not* where you
are. At best, it is the slant-line distance, and at worst it's a
completely arbitrary number because your DME could be kerfliggered.
Furthermore, a VORTAC is more or less a point, but an airport isn't. A
typical airport is many tenths of miles (of either flavor) long/wide.
You'd have to pick an arbitrary point on the field and measure your
distance to that. What do you pick? The tower? What if there is no
tower? The middle of the runway? What if there's more than one runway?
The end of the runway? Which end?

So you see, the actual physical distance from your airplane to an
airport is not even well defined. So when a pilot says "I'm five miles
from the field" what he really means is "I'm somewhere in the vicinity
of five miles" at which point it doesn't much matter what kind of miles
are meant.

rg

In article FviBd.3074$232.1342@fed1read05,
"BTIZ" wrote:

in any case.... the reference is always to nautical.. in this day and age..

Not quite. The correct answer is the one I originally gave:

It's supposed to be always nautical...

Whether the reference actually *is* to nautical or not (and, somewhat
orthogonally, whether this number actually has any relation to physical
reality) depends on whether the pilot knows what they're doing. But,
again, the vast majority of the time it doesn't matter.

rg