Wednesday, January 17, 2007

Changing and Adapting

A former instrument student of mine sent me email a while back with a question about the Salinas ILS RWY 31 approach. His question had to do with the missed approach and he wondered why the approach chart didn't list ADF or DME as being required. I looked at the approach and I, too, was puzzled.

The missed approach holding fix is MARNA, defined by 10.9 DME fix on the SNS 275˚ radial or the intersection of the SNS 275˚ radial and the 207˚ bearing to the MUNSO locator outer marker. Without ADF, DME, or GPS there would be no way for a pilot to identify the missed approach holding fix. So I suggested he email the FAA and report it as a potential error. He did and got a fairly prompt response, thanking him for pointing out the error and assurances it would be fixed in the next revision. Within a week a NOTAM (notice to airmen) appeared saying ADF or DME was required for this approach and, true to their word, the next version of approach charts showed the change. "The system works!" my former student observed.

I regularly use FAA and Jeppesen approach charts, since I may give instruction to pilots who prefer one or the other. I include the FAA charts in examples on my postings here because they are easy to acquire and upload. While looking at the OAK RNAV (GPS) 27L approach, which I used in a recent post, I noticed an error.

The inset map shows the approach course not being aligned with the runway centerline. The course depicted seemed to be for the OAK VOR/DME 27L approach (the Oakland VORTAC is slightly south of the runway centerline). Since the RNAV 27L approach course should be aligned with the runway, I followed my own advice and sent the FAA an email. I also received a prompt reply, thanking me for pointing out the error and an assurance that it would be fixed in the next revision. This got me to thinking about another approach conundrum - the OAK ILS 27R.

The Oakland ILS approach to 27R was changed about four years ago and though I no longer have a PDF that old version, I remember it well. The final approach fix was CASES, 5 NM from the threshold, and it had an outer marker. Four years ago, for reasons that no one seems to know, the FAF was moved out to 5.5 NM. it was named FITKI, and the glideslope angle was reduced slightly. The glideslope intercept was moved in 3.5 miles from URZAF (9 miles out) to FITKI. The odd thing was that the outer marker was still there, it was depicted on the approach chart, but it was no longer part of the ILS approach! I continued to fly with pilots who performed this approach and started their timing to the FAF when they saw the outer marker light flash on their marker beacon receiver, blissfully unaware that they had already passed FAF. I also flew with pilots who still continued to intercept the glideslope at URZAF instead of stepping down to 1500 feet to intercept the glideslope.

Yet after all these changes, the CASES outer marker still had an approach function, at least until last year: It was a step-down fix for the OAK NDB RWY 27R. Alas, the NDB approach is no more. And last year, the ILS approach name was changed to OAK ILS or LOC/DME 27R because it became clear that, without a marker beacon to designate the final approach fix, you'd need DME to fly the localizer-only approach else you wouldn't know when to start descending.

Last week I started nosing around the NACO site and discovered this page where I learned that the OAK ILS RWY 27R will soon be changing again. How soon? Well today!

The final approach fix has been renamed from FITKI to CUVSA, URZAF has been renamed to UPACI, and the missed approach holding fix has been move from PEERE intersection all the way out to REBAS intersection. It appears the old CASES outer marker may finally have been decommissioned and the RORAY locator middle marker has also gone away.

I'm not sure why some of the changes are being made, but one thing is for sure: All of the pilots, instructors, and air traffic controllers will have some adapting to do.


Dave Starr said...

It's good to see these kind of posts with the level of detail and factual discussion, John. Approach procedures, navigation systems and the way pilots should (and shouldn'T0 use them have always been of interest to me.

I'm not sure if you ever heard of or visited the site:
It's still alive, but has none of it's previous maps, articles and discussions. It's owned by a retired TWA captain, Wally Roberts who became a real expert on approach design and procedures during his years with the ALPA ... personally wish he would take up blogging too.

And as a separate subject, thanks (I think ;-)) for the pointer to the Garmin GPS trainer software. There's a heck of a lot to learn, but it's a well put together system ... I know have something that take sup even more time that Microsoft Flight Simulator ... but it's all good.

Eric said...

FAA changes aren't just limited to approach configurations these days. I'm sure you've looked at the FARs related to Sport Pilot certification, but it's totally different from any regulations the FAA has published before.

Not only is it written in plain language - with subpart headers in the form of a question - but it's as if they actually want us to understand what they're saying. I can only hope the same level of clarity and readability is planned to someday be applied to the rest of the FARs.