When would you descend?

[wheelsup]

Originally Posted by pilot602

The plate wants you at 1400 to catch the GS staying at 2000 is technically deviating from the printed procedure.

If it wanted you at 1,400' it would have a line above and below 1,400' (ie mandatory altitude). With a single line below 1,400', it's stating that is the minimum altitude for intercept, doing it (slightly) higher won't hurt anything.

While your concerns over a false glideslope are valid, keep in mind that false GS's occur something around 12-15 degrees above the actual GS (if my memory serves me right). If you're intercepting it from below (in the example above), there is no false glideslope to worry about.

~wheelsup

[B767Driver]

Originally Posted by pilot602

If you're doing a PT you can drop to 1400 as soon as you are inbound on the LOC. As long as you remain inside 15 DME.

If you're coming straight in (NoPT) stay at 2,000 until TBONE then dump it to 1400. Why? Because the plate says to.

I agree with this.

And while I agree it is good technique to always descend to the minimum altitude for the instrument approach at the earliest opportunity (that's what I do)...I see nothing wrong with intercepting the GS at 2000'. You will always be able to check for a false GS at the published crossing altitude.

[VicariousLiving]

Originally Posted by DE727UPS

"If you're doing a PT you can drop to 1400 as soon as you are inbound on the LOC. As long as you remain inside 15 DME"

Looking at the profile view supports your argument.

Also, the transition from Swan keeps you at 2000 until Tbone. Say you do a procedure turn and end up 12 miles out from the VOR on the LOC inbound. Look at the plan view. It shows 1400 inside the 8DME. I'd say that implies 2000 outside the 8DME, procedure turn or no.

So, the obvious question would be: Is TBONE inadvertently missing from the profile view? IOW, have you found a chart error? The best way to test that question would be to send an inquiry to the NACO charting office, per the procedure found within every terminal procedure publication book.

BTW, anyone have Jepp for this airport?

That conflicts with the profile view. I'd use the most conservative route given conflicting data.

Nothing wrong with going conservative provided it doesn't leave the aircaft with a ridiculous descent rate or some other issue. Given that TBONE is crossed at 2000' on the SWAN IAF transition, I can't see where the conservative approach would create a problem on this approach.

[GirlInTraining]

I'm B767Driver... I prefer to stay at a higher altitude, intercept the glideslope sooner, and get established on a final descent profile earlier. Less mucking around with power settings, and a stabilized approach leads to better aircraft control and landings, especially in the weather.

About false glideslope indications: Yes they are certainly possible. If I'm flying an approach and I'm lucky enough to have a copilot, I ask them to verify the altitude passing the FAF. Even before that, though, you *should* be able to recognize that you are descending at some crazy abnormal VVI (underlies the importance of understanding and calculating desired descent rate). If I am staying on glideslope, and my VVI is 1700 fpm, well, something isn't right.

Then again, to each their own technique!