IFR Oddities

IFR Oddities

When I earned my Instrument rating, it was common to include the phrase “No SIDs/No STARs” in the Remarks when filing an IFR flight plan. Partly we were being cheap. In those days you had to buy stacks of paper charts and books even for a single IFR flight, and the SIDs (Standard Instrument Departures) and STARs (STandard ARrivalS) were sold as a distinct series of books. Many personal, recreational and business pilots simply didn’t want to spend the money. Many also assumed SIDs and STARs were something jet pilots do. We piston pilots didn’t need the added complications. By including “No SIDs/No STARs” on our flight plans we knew controllers would not assign us those procedures.

Like many pilots, I tended to find a way of doing things and then stick with it, including this flight plan notation. Then one day I flew from Wichita, Kansas, to Addison Airport northeast of the Dallas/Fort Worth metroplex. I filed “direct” route southbound in that LORAN-equipped speedster. I included No SIDs/No STARs in my IFR flight plan. As I crossed the Red River that forms that part of the Oklahoma/Texas border, I was assigned a new clearance: direct to an intersection, then a series of additional intersections to the airport. I hastily copied the new clearance and then dug out the Low Altitude Enroute chart to try to find where in the world these might be. 

STAR into Addison, TX. It’s undoubtedly different from when I flew the trip described in the mid-1990s, but I flew something akin to MONTE – ROPSS – FINGR and then vectors to KADS.

I must have taken longer than I should because the controller soon came back with a vector to the first fix. I turned on the new heading and finally found the intersection well to the northeast of Addison. From there, I found the two additional fixes in a roughly direct line southwest to the airport. Not being intimately familiar with the rental’s LORAN (a failing for another time), I couldn’t insert the new waypoints. So I deleted the active flight plan and plugged in “direct to” the first fix. I’d do this for each intersection as I passed the last until I was proceeding direct to the airport. 

When the time came to depart, I filed LORAN Direct to Wichita. Clearance Delivery gave me a long set of instructions that began with a heading to intercept a VOR radial, then to an intersection, then along a new radial to a VOR, and then “as filed.” Once more I scrambled to find all this on my enroute chart, then concocted a way to navigate myself along the prescribed route. Feeling pretty good about my ability to make this all up and fly it, I completed my trip and was home for dinner.

I was talking to one of my flying mentors about this afterward. He showed me his book of SIDs and STARs for the Dallas area. Basically, the arrival controller made me fly a STAR and the departure controller made me fly a SID. The level of difficulty was not in the procedures themselves but in my lack of preparation. It would have been far easier for me to have the charts available and to have included them in my IFR flight plan, instead of trying to figure them out in the air. Now it’s far simpler with SIDs and STARs available in most GPS databases. Yet pilots often still file “direct” into busy airspace, adding to their workload later on.

That experience and a few others have taught me there are a number of “IFR oddities” that nonetheless we may be asked to perform with little notice at any time. Sometimes it’s easier to accept the greater responsibility, such as filing a SID or STAR, because it helps you better prepare and therefore reduces your inflight workload. What for one pilot is an oddity may be a Standard Operating Procedure for another. The trick is to reduce the number of your oddities. Here are a few more I’ve experienced.

T-213 and T-215 provide non-vector guidance around the west side of the Cincinnati Class B airspace.

T Routes

Do you remember Victor airways? I’m joking, because for pilots in many areas, for example, the northeastern U.S., flying along airways defined by ground-based VORs is still the norm (even if we fly them using space-based GPS). However, if you earned your Instrument rating more than a decade or so ago, and have not taken an up-to-date Instrument Proficiency Check in that time, the introduction of T routes may have slipped by you. Yet, if you file using an IFR-approved GPS you may be assigned one at any time.  

A Tango, or “T,” route is an enroute airway defined by GPS waypoints instead of ground-based navigation. Just like Victor airways, if you have a GPS that has an airways database, then you can load T routes into your flight plan and include them in your filed flight plan if they make sense. T routes are low altitude airways (from 1,200 AGL to 18,000 feet, just like Victor airways) often used in the busy airspace around major airports, but are also established in locations where VOR stations have been decommissioned. They are depicted in blue on Low Altitude Enroutes. T routes have minimum altitudes similar to a Minimum Obstacle Clearance Altitude (MOCA) since there is no concern about signal reception that is part of the calculation of a Minimum Enroute Altitude (MEA). T routes sometimes have a maximum authorized altitude MAA) also, to deconflict them from arrival and departure pathways into nearby commercial airports. 

T routes are very easy to fly as long as you know they exist. Look for them as you plan flights that get close to Class B and busier Class C airports, and include them in your flight plan to avoid having to make an inflight adjustment. 

Unexpected Holds

When was the last time you were unexpectedly assigned a holding pattern outside of a training environment? I’ve been instrument rated for over 30 years, and as best I can recall the answer for me is “three.” Once was an IFR arrival into Tullahoma, Tennessee for a fly-in and I had to wait my turn for the approach at the nontowered airport. Another was also a hold for traffic ahead of me for an approach. The third time was a radar outage, and the controller was shunting me and a bunch of others into holds until they could re-clear us all onto airways.

I’ve also done dozens of holds after instrument approaches that resulted in missed approaches because of real-world below minimums weather. But I don’t consider those holds to be “unexpected” because I reviewed them beforehand as part of my instrument approach brief.

Yet, you can be assigned a hold at any time and be expected to carry it out flawlessly. It’s recommended that ATC provide at least three minutes notice of a hold based on your current ground speed, but even that is not absolute. If you’re assigned a published hold, that is, a holding pattern depicted on an instrument publication, it’s easy to visualize the pattern and from there how you will enter – if you know where to look. The hold may be “published” on a Low Altitude Enroute chart, or an approach chart, or a SID or STAR…but not necessarily on all of them. 

If you can’t find the depiction right away, treat it like an unpublished hold. In that event I recommend a simple technique: draw the picture. On your kneeboard, electronic tablet or whatever you use for notes and clearances in the cockpit, draw a little triangle or dot representing the holding fix. Then draw the hold’s racetrack pattern remembering that you hold inbound on the direction you’re told to hold (i.e., if told to “hold southeast,” you’ll be heading northwest as you approach the holding fix). Remember also that standard holding patterns have right-hand turns unless you are told otherwise (backward from traffic patterns and circling to land). 

Find or draw the picture, then visualize (or draw) a line that represents the direction you’re headed toward the fix before holding. Then figure out your holding pattern entry. Of course, some GPS units give you the ability to draw an unpublished hold electronically and even let the autopilot fly your newly defined hold. No matter what technology you use, practice it a few times under the hood because you never know when you might be tasked to do this in actual IMC with little warning.

Filed vs. Expected

The last IFR oddity I’ll cover is not one of the basics you may have forgotten or even a new rule that has changed IFR operations. It’s an artifact of the great capabilities provided by modern Electronic Flight Bag (EFB) flight planning software in common use all the way down to basic training airplanes. It’s called an “expected route.”

When you file an IFR flight plan, some EFB software compares your route to previous clearances issued to aircraft flying the same approximate route in the altitude range you’ll fly. If the ATC record suggests your route will be different from what you filed, the EFB software notifies you. The idea is for you to find out, in advance, if there’s an IFR Preferred Route (remember those?) or other preference for routing that may result in getting something other than “cleared as filed” when you call for your clearance. Most EFB software will let you accept this new route with a single acknowledgment, and replaces your filed route with this new information.

What happens if you receive an expected route, tap the screen to accept it, then ATC tells you “cleared as file” when you obtain your clearance? You are not cleared via the expected route. As filed means as filed. If you’ve already loaded the expected route into your panel you’ll need to re-load the original. Here’s what I learned to do when I get an expected route notification: I load it into a new flight plan alongside the one I’d filed. I do not upload anything to the airplane’s panel until after I received my clearance. If I’m cleared as filed, then I upload my original filed flight plan. If I’m given anything else, including the expected route, ATC will have to give me a full route clearance. Once I’ve copied it and confirmed it matches the “expected” route, I’ll make that route active on my iPad and then sync it to my panel. 

I’ve heard of pilots loading the expected route prematurely and assuming it was what ATC meant by “as filed” because the new route came from Air Traffic Control. Flying the expected route under those circumstances would result in a deviation from your clearance – at best.

There are a great many IFR oddities, and what’s odd to me might not be odd to you. Some come from failing to learn something new that ultimately reduces workload tremendously. Some arise from rules that didn’t exist when you earned your instrument rating. Some are the result of the cockpit technology we use to fly more efficiently in the IFR system. All are potential traps if you’re not prepared. And you may be called upon to fly an IFR oddity at any time. 

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