"Cleared Straight-In Runway X; Report Y Miles Final"

"Jim Cummiskey" wrote in message
...
Actually, no. If you think about it, if you approach the numbers at a ~30
deg angle, and a "proper" downwind to base turn is made at a ~45 deg
angle,
there will be no conflict whatsover.

How do you figure that? Firstly, the "45 degree key point" taught students
for where to turn base is just a rule of thumb...base turns are made much
earlier and much later than that, depending on factors other than just
following a rote procedure.

Secondly, the flight path of an airplane flying 90 degrees to the runway
heading on base intersects the flight path of an airplane flying 30 degrees
to the runway heading, heading straight for the numbers. Since the flight
paths intersect, there certainly IS a potential for a conflict.

I'd agree that the odds of there being a conflict on the downwind leg
(rather than the base leg) are low (though not nonexistent since extended
downwinds are a common enough procedure, especially at towered airports),
but to say that "there will be no conflict whatsoever" is hugely and
inappropriately optimistic.

Pete

Hi,

Recently, Peter Duniho posted:

"Jim Cummiskey" wrote in message
...
Actually, no. If you think about it, if you approach the numbers at
a ~30 deg angle, and a "proper" downwind to base turn is made at a
~45 deg angle, there will be no conflict whatsover.

How do you figure that? Firstly, the "45 degree key point" taught
students for where to turn base is just a rule of thumb...base turns
are made much earlier and much later than that, depending on factors
other than just following a rote procedure.

Secondly, the flight path of an airplane flying 90 degrees to the
runway heading on base intersects the flight path of an airplane
flying 30 degrees to the runway heading, heading straight for the
numbers. Since the flight paths intersect, there certainly IS a
potential for a conflict.

This thoery is correct, AFAICT. However, in practice that should get the
controller issuing such a clearance fired. I don't *ever* want to be on a
straight-in 5 mile final if other traffic is going to wind up on some
random variant of base at the same time. That said, There are many times
at controlled airports (and even more at uncontrolled airports) when there
are aircraft on base and final (and everywhere else) at the same time. The
controllers call out those positions and issue a clearance if the other
traffic is in sight. I've also had controllers call my base turn during
heavy traffic.

IOW, the controller's job is to insure spacing. As Jim hasn't mentioned
whether there was other traffic inbound or in the pattern, I'd think that
would be an important factor in whether he was right or wrong to be
off-center. If there was no traffic, there'd be no conflict and the
controller was just being manipulative. If there was traffic, and the
controller didn't call it out, that might be grounds for complaint. After
all is said and done, the FARs make it quite clear who the PIC is, and one
requirement is that they're in the cockpit.

Neil

"Neil Gould" wrote in message
link.net...

IOW, the controller's job is to insure spacing. As Jim hasn't mentioned
whether there was other traffic inbound or in the pattern, I'd think that
would be an important factor in whether he was right or wrong to be
off-center. If there was no traffic, there'd be no conflict and the
controller was just being manipulative. If there was traffic, and the
controller didn't call it out, that might be grounds for complaint. After
all is said and done, the FARs make it quite clear who the PIC is, and one
requirement is that they're in the cockpit.


He's wrong whether or not there was other traffic. He did not follow the
controller's instruction.

unicate (Shirley) writes:

That's my question too ... why would you consciously choose to fly 30° off? why
*wouldn't* you line yourself up with the centerline (*straight*-in)?

Sometimes (but obviously not in this case) controllers will ask to
"take it to the numbers." It's one of my favorite requests.

--kyler

I would interpret her clearance to mean I should report
5 miles out on the extended runway center line. There
could be traffic issues that caused her to request you follow
this path to the runway.


"Jim Cummiskey" wrote in message
...
Hi, all. Ran into this one flying back from KOSH a couple weeks ago:

I check in with the KPRC controller "20 Miles NE" of Love Field in
Prescott,
AZ. She clears me with "Cleared Straight-in Runway 21L, Report 5 miles
final."

I fly directly towards the numbers. My heading was approximately 240
(hence, I'm ~30 deg off of the extended centerline).

At 5 miles from the airport (still offset from the centerline), I report
"5
mile final." She questions my position and gets all snippy (indeed, darn
right rude) that I am "not on final" since I am not on the extended
centerline. She patronizingly cautions me to be "careful about this."

Hence, the question is "What does 'Cleared Straight-in; Report X miles
Final" really mean?" Is it. . . .

(1) You must fly directly from your current position to a point on the
extended centerline that is X miles from the numbers, and then report
(sounds like a base to me).

or

(2) You can fly directly from your current position to the numbers (thus
"straight-in"), and report when you are X miles away.

I obviously vote for #2, but the controller clearly thought otherwise (it
seems to me that if 30 deg = "straight-in" in the IFR domain, it ought to
work well enough for VFR situations). Regardless, it is potentially
dangerous when controllers and pilots define things differently. Which
definition is right?

Regards, Jim

She said cleared "straight in" for runway 21L. That (to me) is to come in
on the final approach path, i.e. extended runway centerline. I think tower
controllers always give you a position to enter the airport traffic pattern.
They either give you a downwind, base or "straight in" (i.e. final).

In your situation I think I would have adjusted course to intercept the
final approach fix or the runway centerline 5 miles out which ever was
greater.

Further, it might have been a concern of hers that from your position 240
degrees coming in to 21L you would cross the final approach path of 21R on
short final. If she assumed you'd be on the extended center line of 21L she
might have cleared someone on 21R at the same time making a dangerous
situation.

Kobra
(no expert)


"Jim Cummiskey" wrote in message
...
Hi, all. Ran into this one flying back from KOSH a couple weeks ago:

I check in with the KPRC controller "20 Miles NE" of Love Field in
Prescott,
AZ. She clears me with "Cleared Straight-in Runway 21L, Report 5 miles
final."

I fly directly towards the numbers. My heading was approximately 240
(hence, I'm ~30 deg off of the extended centerline).

At 5 miles from the airport (still offset from the centerline), I report
"5
mile final." She questions my position and gets all snippy (indeed, darn
right rude) that I am "not on final" since I am not on the extended
centerline. She patronizingly cautions me to be "careful about this."

Hence, the question is "What does 'Cleared Straight-in; Report X miles
Final" really mean?" Is it. . . .

(1) You must fly directly from your current position to a point on the
extended centerline that is X miles from the numbers, and then report
(sounds like a base to me).

or

(2) You can fly directly from your current position to the numbers (thus
"straight-in"), and report when you are X miles away.

I obviously vote for #2, but the controller clearly thought otherwise (it
seems to me that if 30 deg = "straight-in" in the IFR domain, it ought to
work well enough for VFR situations). Regardless, it is potentially
dangerous when controllers and pilots define things differently. Which
definition is right?

Regards, Jim

Mike Adams wrote:
More likely is what others have said - by staying
on the centerline, they have more flexibility to
sequence traffic on the left downwind, and others
can spot you easier if you're in a predictable
location.

Others spotting you easier where most would look if they hear someone is making
a "straight-in" approach is the best reason, IMO.

Something similar happened to me today at an uncontrolled airport that brought
this discussion to mind. As I was about to enter the 45 for a left downwind, I
heard another aircraft announcing that they were on the left downwind. I
scanned the entire area but did not have them in sight. I announced when I was
on the 45, still looking. As I entered the downwind, I announced and asked the
other aircraft for an update on their position. He said he was on an "extended
downwind, about to turn base." I looked everywhere, but expected to see him
more or less way in front of me and/or to the left as he made his left base
turn. Instead, I finally saw him coming across from my right (I was still on
downwind) making what I would describe as a *diagonal* combination base/final
straight from some point WAY out to my right!

Of course, he was considerably further than 30° off of the centerline, but more
important was that his description wasn't accurate for where he was or what he
was doing. IMO, he was on a *WIDE* downwind, which he didn't say, and he didn't
"turn base," he just flew a diagonal line to the runway! I interpret "extended
downwind" to mean traveling further downwind before turning base, not flying
the downwind 1.5 miles away from the runway.

If I were an ATC today, I sure would have said something, too!

Jim Cummiskey wrote:

Actually, no.

Actually, yes.

If you think about it ...

What makes you think I haven't?

... if you approach the numbers at a ~30
deg angle, and a "proper" downwind to base turn is made at a ~45 deg
angle,
there will be no conflict whatsover.

When you reach the point in your training where you start flying at
towered airports, you'll discover that there's no such thing as a
"proper" pattern. Downwind and base legs (as well as upwind and
crosswind legs) are extended and shortened for a wide variety of
reasons, to allow planes in and out of the airport effectively.
Especially when the airport is busy.

You'll also discover that there are larger, faster airplanes - some
even with jet engines - that fly larger patterns, and that can affect
(and can be affected by) traffic farther away from the airport. You
may have already discovered this flying around the pattern at your home
airport. If not, you may want to discuss this with your instructor
before he lets you solo.

Regardless, a plane flying "to the numbers" from 30 degrees off the
downwind side will cross every possible base leg to that runway.

It will also cross every possible downwind leg at some point. For
example, a plane on downwind set up for a 1/2 mile base leg could
collide with the inbound plane 0.866 miles downwind from the numbers.

On the other hand, if that inbound plane were to set up for a 5 mile
final, there would be no possible conflict for any pattern
configuration inside those 5 miles. That's a great reason for a tower
controller to ask for it.

"Brien K. Meehan" wrote in message
...

Regardless, a plane flying "to the numbers" from 30 degrees off the
downwind side will cross every possible base leg to that runway.

It will also cross every possible downwind leg at some point. For
example, a plane on downwind set up for a 1/2 mile base leg could
collide with the inbound plane 0.866 miles downwind from the numbers.

On the other hand, if that inbound plane were to set up for a 5 mile
final, there would be no possible conflict for any pattern
configuration inside those 5 miles. That's a great reason for a tower
controller to ask for it.


It's a good reason if she has or anticipates other traffic.

"Brien K. Meehan" wrote in message
...

Regardless, a plane flying "to the numbers" from 30 degrees off the
downwind side will cross every possible base leg to that runway.

It will also cross every possible downwind leg at some point. For
example, a plane on downwind set up for a 1/2 mile base leg could
collide with the inbound plane 0.866 miles downwind from the numbers.

On the other hand, if that inbound plane were to set up for a 5 mile
final, there would be no possible conflict for any pattern
configuration inside those 5 miles. That's a great reason for a tower
controller to ask for it.


It's a good reason if she has or anticipates other traffic.

Ity's probably time for the OP'er to say he now sees he may have been in error.
The good thing about posting the quesiton is that it also may have made some
readers more aware of what ATC instructions mean.

As an aside, a long tiome ago I was making an ILS into BED after dark, and
tower asked me for a landing light so they could see where I was (this was a
long time ago). Now that was a time when I did not comply with tower -- a
landing light in the clouds is a good way to really screw up night vision. I
told them the landing light would have to wait until I had the runway in sight.