Hold Vs. HILPT

A reader, a helo pilot from the U.S. Coast Guard, wrote to ask some interesting questions. It seems they’d just had an FMS upgrade that enables them to fly RNAV (GPS) approaches. All the approach holds that are course reversals (hold in lieu of procedure turn, HILPT) are shown with four-nautical-mile legs. He asked if it is required to fly the entire leg length.

The e-mail discussion evolved to ask if a charted hold, such as a missed approach hold, also had mandatory leg lengths. These probing questions prompted some interesting virtual discussions at IFR. Then, just as we were preparing this article, another helo-pilot reader sent us an FAA Legal interpretation mucking with our reasoning.

Not the Same

HILPTs, which can be flown as full holds, have different purposes than an actual hold and should be thought of with those differences in mind.

The HILPT is a course reversal using entry techniques prescribed for a hold. You enter the hold using the normal entry techniques, but crossing the fix inbound, you just fly the final approach course.

So, a HILPT is not a full hold, but you can hold there. Say you’re coming from the en route structure and you find you’re still way above the minimum crossing altitude for the HILPT fix inbound. Or, perhaps you’re just not ready for the approach and need a little more time. No problem; just make a circuit of the hold.

But, ATC isn’t expecting that pass around the race track. So, you should keep the controller in the loop.

In fact, if you want a full turn or more in the hold to lose altitude or get yourself prepared, you’re advised by AIM 5-4-9 a.5. to request the hold from ATC: “The holding pattern maneuver is completed when the aircraft is established on the inbound course after executing the appropriate entry. If cleared for the approach prior to returning to the holding fix, and the aircraft is at the prescribed altitude, additional circuits of the holding pattern are not necessary nor expected by ATC. If pilots elect to make additional circuits to lose excessive altitude or to become better established on course, it is their responsibility to so advise ATC upon receipt of their approach clearance.”

That should just be a simple notification: “After the course reversal, I’m going to need a full circuit around the hold to lose some altitude.”

Another reason you might hold over the HILPT point is there might be an aircraft on the approach ahead of you and the controller needs to delay your approach. So, you get a hold over that fix. Obviously, in this case, ATC is already in the loop so you need do nothing more than acknowledge the clearance for the hold (and report your entry).

HILPT Entry

You’re flying the RNAV (GPS) Runway 31 approach into Yankton, SD (KYKN). You’ve been cleared directly to the YKN VOR to fly outbound on the final approach course and perform the course reversal via the HILPT at HUGAT. What entry will you use for the HILPT?

The official guidance we get on hold entries puts the dividing line between a parallel and a tear drop entry on the reciprocal of the inbound course for the hold. Unfortunately, we’re exactly on that reciprocal of the inbound course, so technically, we can make either a parallel or a tear drop entry. The official entry per the FAA is ambiguous. Take your pick.

So, with the choice being yours, which will you pick? Well, if you’re like most of us with GPS, we’ll “pick” the one the GPS flies, and probably do so without even bothering to look at what it plans to do. After all, it knows what to do, right? But, do you know what it’ll do?

Garmin’s GTN-series navigators will fly a teardrop entry. We like this and are guessing that other navigators that can fly the hold entry for you will also fly a teardrop, but we haven’t checked.

But, if you’re flying behind an older navigator that can’t automatically handle this hold entry for the course reversal, some of you might choose the parallel because, well, there’s less to think about. You’d just continue past the hold fix for a minute, then turn left around direct back to the fix. That’ll work, but we’ll recommend it’s not as good as the teardrop.

Since the inbound course on the hold is the same as the final approach course, if you fly a teardrop entry, you’re already tracking the final approach course in the hold and have additional time to get stabilized. Then, when you cross HUGAT, all you have to think about is the descent. You don’t have to worry about changing course.

If you chose the parallel entry, as you crossed HUGAT toward the airport, you’ll have to both turn to get on the final approach course and begin your descent. Of course, in this example you only have 400 feet to lose and 7.4 NM to do it in, so the added workload is trivial. But instrument flying is all about reducing your work load and keeping things easy.

So, in that spirit, using a teardrop entry for HILPTs where the inbound course on the hold is about the same as the final approach course, might just make your life a bit easier.

Shorter HILPT?

Now that we know the difference, can you shorten the legs of the HILPT entry? Sure. Just don’t exceed them. AIM 5-4-9 a.5 gives us that freedom: “The holding pattern distance or time specified in the profile view must be observed. For a hold−in−lieu−of−PT, the holding pattern direction must be flown as depicted and the specified leg length/timing must not be exceeded.”

While at first glance that seems restrictive, the real restriction is simply not to exceed the leg length. Thus, yes, you can shorten your entry.

Again, however, while shortening your entry is permitted, it’s best to keep the controller in the loop. This was a point for our helicopter pilot who could fly the course reversal in minimum time or distance. So, just let ATC know: “We’ll only need one mile past ZORIM for our course reversal, so we’ll be inbound in a minute or so.” Most of the time the controller will respond suggesting s/he doesn’t really care, like, “Uh, roger.” Still, though, it’s best to assure you both have the same expectations.

Full Holds

There are four common occasions when you might fly a full hold: at some en route fix to hold for congested traffic ahead, on an approach due to preceding traffic or your own need to further prepare, at a missed approach holding fix before rejoining the en route structure, and on departures to climb to a safe altitude.

In most of these cases, the holding pattern is charted and should be flown as depicted. The depicted holding pattern meets minimum obstruction clearance requirements. To assure you safely stay clear of obstacles and terrain, remain within the depicted holding pattern airspace.

So, for example, if the charted holding pattern is depicted with seven-nautical-mile legs as in the chart, you must not exceed that leg length or you risk leaving the protected airspace. Likewise, if a leg length is not indicated, the leg lengths are determined by timing. (You remember: At or below 14,000 feet MSL, the inbound leg is one-minute long. Above 14,000 feet MSL, the inbound leg should be a minute and a half.)

We’re now back to the original question. Are these mandatory leg lengths or can they be shortened? For all but the climb-in-hold procedure on departure, these holds will typically be assigned by ATC. Sure, there’s the lost com possibility, but under normal circumstances, you’re assigned the hold by ATC.

In a charted hold, we believe that the leg length—either implicit timing or explicit length—is part of the depiction. This then becomes part of your clearance and should be flown as depicted. In fact, that’s the clearance you’ll get: “Hold east as published.” While the hold clearance isn’t optional, hold details are often negotiable.

The controller is assigning you a hold simply because for some reason, your path ahead isn’t ready for you (or you for it). So, the real goal is just halting your forward progress. Excepting terrain concerns, it seldom makes any difference to the controller what leg length you fly. So, if you want to do something other than as assigned and/or depicted, ask. You’ll probably get it.

Hold Shorter?

As noted above, a reader sent us a copy of an FAA interpretation about shortening assigned holding leg lengths. On January 11, 2011, Rebecca MacPherson, Assistant Chief Counsel for Regulations, responded to Bill Young. One question had to do with shortening DME legs in a holding pattern and she replied, “…it is permissible, without specific ATC clearance, to shorten published outbound DME legs in a holding pattern as long as the issued holding pattern leg length is not exceeded. If ATC verbalizes leg lengths for either a charted or uncharted holding pattern, the pilot does have to obtain ATC clearance to shorten outbound legs to less than that which has been cleared.”

While clear, to us this isn’t definitive. First, it only deals with DME leg lengths. One might assume, but it isn’t said, that this also applies to leg timing. Next, it says that you can’t shorten a leg if ATC verbalizes leg lengths. This suggests that leg lengths can be shortened on implicit holds, such as a climbing hold on departure or reaching a clearance limit, but not on explicitly assigned holds.

But, we seldom, if ever, get implied holds any more. So, is “Hold east as published,” a “verbalized leg length”? While the controller in our example didn’t exactly “verbalize” leg length, we’d argue that “Hold east as published,” is sufficiently verbalized that one might get in trouble flying shorter legs regardless of Ms. MacPherson’s interpretation.

While this is an interesting and probably useful intellectual discussion, it lacks practical application. As we’ve said repeatedly, “When in doubt, ask.” So, if for any reason you want to fly different leg lengths from what you were either explicitly assigned or different from what is charted, regardless of whether we or anyone else has said it’s okay to do so, simply ask.

By asking, you’ve not only assured that you’re in compliance, you’ve also assured that both you and the controller have exactly the same expectations in what could otherwise be a confusing subtlety of legal interpretations between you, the regs and the FAA. And, when it comes down to a conflict of that subtle interpretation, guess who wins.

So, all this exploration of whether you can legally fly a shorter holding pattern or HILPT entry, all essentially boil down to a simple answer: “Ask the controller.”

Frank Bowlin asks ATC for clarifications on lots of things, primarily because he can’t remember all these nuances anyway.