Instrument pilots know that there are two ways to start an instrument approach: they can get vectors or fly direct to an initial approach fix (IAF). Last month, I wrote about the “new” third way to start an approach, by flying to the intermediate fix (IF). This month I planned to write about the challenges in requesting to start an approach at an IF. Coincidentally, the day this article was due, the problem I planned to describe occurred…again.
I added quotes to “new” because, while this third method has been described in section 5-4-7(i) of the Aeronautical Information Manual (AIM) since 2006, I expect it will take many years before this information fully permeates the pilot and controller populations. Why so long? Partly because old habits in aviation die slowly and because standard IFR phraseology is confusing when applied to starting at an IF.
The confusion is not unlike the language issues that led to “Position and hold” being changed to “Line up and wait,” a change I enthusiastically supported. Countless times I’ve been in the cockpit with a pilot who confused “Position and hold” with “Hold short,” presumably because they both contained the word “hold.” In this case, potential confusion exists with the words “vectors” and “direct to,” when used to request to start an approach at an IF.
In September 2012, I exchanged several emails about this problem with a friend who is a supervisor at the Northern California TRACON. In my first email, I wrote in part,
“In my books, I tell pilots that there are three ways to fly an instrument approach:
2. own navigation (or pilot navigation) to an IAF, and
3. a third method, which appeared in the Aeronautical Information Manual beginning in 2006 that allows pilots to start at an IF under certain circumstances (see extract from my G1000 Book below).
“We have short, well understood names that pilots use to ask controllers for the first two methods. But I’m not aware of a convenient name for pilots to use when requesting this third method. Are there quick, easy names that controllers use to describe this third method? Or should we be inventing a new name for it and promoting it among the aviation community?”
Why the need for a “quick, easy name?” Because for years, I’d sometimes had to clarify my request to start at an IF by adding that I’d like “to be vectored to a point from which you can clear me direct to DOCAL with a turn of less than 90 degrees.” That’s a mouthful and an inefficient use of radio time at a busy TRACON.
The reply from my supervisor friend was that the consensus at the facility was that a pilot should name the approach and ask to start at the name of the IF. In the case of the GPS 31 approach at Palo Alto, a pilot would ask to “start the approach at DOCAL,” Alternatively, you might consider requesting “to start the approach at the Intermediate Fix,” which should trigger the controller to remember the 90 degree turn rule.
Potential Confusion in Phraseology
Using the words “vectors” or “direct to,” works great when a pilot is requesting to start an approach with vectors or at an IAF. But they can be confusing when used to start an approach at an IF.
“Vectors” means you’ll be guided to join an approach at least several miles outside of the final approach fix (FAF). Requesting “vectors to DOCAL” could make sense, except that the JO 7110.65U tells controllers that when giving vectors, they are to turn pilots to within 30 degrees of the final approach course, not the 90 degrees permitted at an IF. So you don’t really want “vectors” to the IF.
If instead of asking to “start the approach at DOCAL” a pilot asks to be cleared “Direct to DOCAL,” controllers will sometimes take that literally and clear a pilot from their present position to the IF. But this can result in nearly a 180 degree turn at the IF, which isn’t permitted under 5-4-7. And that’s exactly what happened to me today. I had just crossed over Moffett Field and was essentially on a downwind leg to the approach. The controller asked whether we wanted vectors or to start the approach at DOCAL. I chose the latter and was immediately cleared “Direct to DOCAL.”
I’m not sure why the controller did that, though I’m guessing he was familiar with the 90 degree rule in 5-4-7. Shortly afterwards, I said “we’d like to continue on this heading until we can make a turn of less than 90 degrees at DOCAL,” to which he said “That will be fine.”
Why so casual? We weren’t IFR, but were doing a VFR practice approach, where separation standards are relaxed. Under those circumstances, I’ve seen controllers not require a turn of less than 90 degrees at an IF, a practice that may confuse pilots and controllers alike about the proper way to start an approach at an IF.
Get on the Same Page as the Controller
Regardless of how you request an approach, or how you are cleared to an approach, it’s important to be on the same page as the controller. If you have any doubt as to whether the controller and you have the same game plan in mind, request clarification. In the meantime, don’t hesitate to ask to “start the approach at the IF” if that’s how you would like to fly the approach.
The opinions expressed by the bloggers do not reflect AOPA’s position on any topic.