Confusion about when it's my navigation, and when it's ATC

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Mxsmanic wrote:
A Guy Called Tyketto writes:

Look CLOSELY at those charts, and I mean closely.

Which charts? I have VFR sectionals and TACs, plus SIDs, STARs, and
instrument approach plates, but no IFR charts.

I just told you. LOOP4, KEPEC1, ILS 25L at KLAS. Those are also
charts.

The aircraft is RNAV-capable, but I will grant that I didn't notice
that it was RNAV. I just look at the fixes and so on most of the
time, knowing that ATC will probably tell me to do something
different, anyway.

You should look at those, because if you choose the wrong
chart, and your equipment can't support the chart you're filing, you'll
be given another SID/STAR to use.

Yes, it's a BBJ2 or 737-800, and I know ATC a little in the area, as I
fly around there a lot.

You best look at the LOOP4 chart again, as you have 2 crossing
restrictions you must meet. You must cross the SMO R-160 at or
below 3000ft.

I believe the FMC knew that, although I wasn't watching to see. ATC
had already told me to climb and maintain 5000, which I assumed
overrode all other instructions.

If you lost your FMC, what would you do? You just can't let
your instruments do everything for you the moment you rotate. I'd
fathom to see what would happen if you were a /A and didn't have an
FMC.

Now, you're en route, and you're ready for the arrival. You're
still at FL290. Staying that high until your FMS starts to descend is
really going to increase your descent rate, as well as try its hardest
to maintain a slow speed for your descent. Not good.

I recall stepping through the legs looking for anything that seemed
like a steep descent and possibly tweaking some legs, although I don't
remember the details.

What I do remember is that I reached the top of my descent and the FMC
started down, then ATC called me and asked why I was low. So I reset
the MCP to FL290 and went back up. Seconds later, Center told me to
cross something at something (I don't remember what now). My guess
was that he forgot that I'd be starting my descent and remembered when
he saw me descending, so he called me on it and then cleared me down.

I doubt it. There's two places where the Center controller
could give you the crossing restriction; one at MISEN, the other at
CLARR. If he gave you the one at MISEN (which I know he did), it would
make the CLARR crossing restriction a lot easier to make.

"Cross CLARR at and maintain 13000 and 250kts. Las Vegas
altimeter xx.xx".

Yes, I recall getting that.

"Descend via the KEPEC1 arrival".

Unfortunately, they vectored me around, and then told me to follow
some traffic going the opposite way (towards the airport, whereas I
was still headed east). I messed up so much fiddling with the FMC and
autopilot that I couldn't follow the other guy in, so I had to go
around. Then it was more vectors, and following someone else in. I
gave up on the AP and flew by hand towards the other aircraft, then
intercepted the localizer and configured everything for a nice
autoland.

They had visual approaches in use. Also, it has been said
befo 99.9% of all landings are hand flown, not autolanding, unless
on a Cat III ILS approach. ILS 25L is not CATIII.


OK. I will ask next time. I have yet to do an approach (in the
presence of ATC) that followed the plates, though. Somebody always
wants me to do something different.


It could be because visual approaches may be in use over using
an instrument approach. It provides more flexibility with ATC, plus
puts separation responsibility back on the pilot. If you were following
traffic, and you were coming in too fast and had to go around, that may
not be ATC's fault. There would be some things you could have done to
slow your speed down.

BL.
- - --
Brad Littlejohn | Email:
Unix Systems Administrator, |
Web + NewsMaster, BOFH.. Smeghead! | http://www.wizard.com/~tyketto
PGP: 1024D/E319F0BF 6980 AAD6 7329 E9E6 D569 F620 C819 199A E319 F0BF

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