Last updated 29-Nov-1998.


Pelican's Perch
by John Deakin

Pelican's Perch

Using A Handheld -- IFR

Never one to let a good idea, or safer method of flying, wither away for lack of action or misunderstanding, AVweb's John Deakin takes on the subject of flying IFR with your GPS handheld. "Not legal," you say? "Not so," says John. Flying IFR with your handheld GPS is not only legal, it's a godsend he says, and explains just how to get the most out of that handful of navigation wizardry.

John DeakinCan't do it? Rubbish!

Yeah, I know, the handheld is not FAA-Approved, or TSO-129 compliant. Well, neither is a #2 pencil, but that doesn't mean you need an FAA-approved pencil (yet) to write down a clearance, and you don't need an IFR-approved GPS to use one while IFR, either. I wouldn't be so hot on this subject, except for the fact that IFR certification has made most of the IFR-certified units less useful, and perhaps even less safe, than many of the handhelds! The IFR panel-mounts are much more complex, harder to use, and with far less in the way of features, and data, thanks to the difficulty and expense of getting through the FAA certification process.

The key to this discussion is separating what you must have on board the aircraft for IFR flight, from what you actually use and how you must use it.

The Minimalist Approach

SkyStar FAR 91.205(d)(2), which covers minimum equipment for IFR flight says "Two-way radio communications system and navigational equipment appropriate to the ground facilities to be used."

I take this to mean that if you have VOR and/or ADF on board for the navigation, you're covered in the USA, provided you can reasonably use it to get where you're going and shoot an approach there. It doesn't say you must use that old stuff.

Major Warning!

Note carefully, you cannot legally fly IFR with a handheld GPS, if that is the only navigation device on board, and we may never be able to do that, even with fully-approved, IFR GPS.


Now that we're all used to "slant Romeo" for "Area Nav," the FAA went and changed it by NOTAM (The AIM hasn't been changed yet, at least as of August 13, 1998). Now, "/R" refers to a system of trans-oceanic navigation with very high accuracy. The new designator for "Area Navigation" is "/I" ("Slant India"), or "/G" ("slant Golf") for an IFR-approved GPS.

The /I designator is only used if you truly have an approved Area Navigation system, which can be the old King KNS-80, or an approved IFR Loran. The /G is used only for an IFR-approved GPS. There are other systems, but they are not usually found in the GA world.

What suffix do you file if you have only a handheld GPS, and the usual VOR/ADF? You simply disregard the GPS, and file whatever code indicates the rest of your gear, typically DME and Transponder, perhaps /A or /U.

Some with VFR-only GPS add in the "Remarks" area "VFR GPS" or "GPS on board". This is not really necessary, but for a "with-it" controller, it does let them know you do have some additional capabilities, even if unapproved.

Flight Plan Routing

Airmap 100 First, I suggest you find the "Preferential Routes" pages, and simply throw them away forever. I find them totally useless, antiquated artifacts of an earlier age. They are often out of date, and besides, ATC will give you "the plan of the day" anyway.

Unless I have some reason (weather, hostile terrain, etc.), I invariably file IFR from my point of departure to my destination, "direct" with no intermediate waypoints. You folks who fly in the Northeastern USA will be having fits of giggles at this, but never mind, "direct" is a way of life everywhere else!

You will sometimes find a briefer, or an "intermediary," who believes this is not proper, and they may fuss, wanting a more complex routing. It's up to you how hard to push this, but they are dead wrong. Both the humans and the computers involved can handle this simple routing with aplomb. I had this happen at Hawthorne (HHR) some time ago after I had computer-filed IFR direct to Seattle's Arlington airport (AWO). The poor guy working Hawthorne Ground Control came back and said "LA Center says you've filed an invalid routing, and they need a more complete route." We went back and forth a bit, and finally he said "I don't have the foggiest idea who's right here, but this guy is getting testy, suggest you contact Hawthorne FSS and file a route that the computer will take."

So I called them on the radio and explained the problem. The fellow said something (in a disgusted voice) to the effect that LA Center didn't know what they were talking about and came back a moment later with, "No problem, just call Ground Control again, have a nice flight." By the time I switched, ground had my clearance, "Cleared to AWO via radar vectors, direct, fly heading 210 after takeoff." Perfect.

It wasn't that the computer wouldn't take my flight plan, the person working it probably wouldn't even punch it in, thinking there was no way it would work.

It is a sad fact that some modern wristwatches have more (and faster) electronics than the current FAA computers--and with a lot more storage, too. The FAA computers can barely contain the minimum data on major airports and navaids within one Center's airspace, and a few other major terminals in airspace outside their own center. As a result, if you file direct in either direction between Arlington, Wash., and Hawthorne Calif., the computers will be very confused, and will be unable to process the flight plan. For this reason, it is best to file "DeparturePoint direct Lat/Lon direct Destination", with the "Lat/Lon" being the latitude and longitude of the destination. That way, the computer can calculate the direction and distance from the point of departure to some point beyond their boundary, and it doesn't care what's next, or that the next point (the destination) is the same as the Lat/Lon. Stupid computers go for stupid solutions. It looks like this:


In the "Remarks" section, it is best to note: "Lat/Lon is KHHR." That will let the humans who process the flight plan know what's going on.

With this, the ATC computer (or its operator) may not know where KHHR is, but it can find that Lat/Lon, and thus "knows" the direction of flight, which the only thing it really cares about.

Flying "Direct"

Precedus First, in today's real world, ATC simply assumes that everyone has the capability to go direct anywhere, and they simply don't care how it gets done. Even if you don't file a suffix that indicates Area Nav, you'll sometimes get a clearance that can't be done any other way. I've even had controllers get a little annoyed when the response is "Unable Direct". Yes, yes, technically the controller is supposed to check the suffix and not assign "direct" unless the aircraft shows Area Nav capability, but more and more, few bother and they just assume it's so. In real, practical terms, it's up to the pilot to accept or reject, which is just as it should be, in my opinion.

Another trick when asking for advisories is when, for example, Seattle Center asks "Where is HHR?" I'll answer "Hawthorne, California," and the next question is sure to be, "What are the coordinates for that?" because the SEA computer doesn't know them. It is ironic that my handheld Garmin 195 knows where every airport, VOR, NDB, Intersection, and SUA is in the entire Western Hemisphere, plus airport data on all of them, and terrain features, but Seattle's mainframe computer doesn't know where HHR is. If I think the controller is busy, I'll often just say "Aw, just punch in my destination as LAX, and I'll sort it out with LA Center later." Usually, there is an on-air sigh of relief, and "Thanks!" That way the computer is happy, I'm happy, and the controller doesn't have to punch in a bunch of numbers, so he's happy. Once I'm turned over to L. A. Center, I'll say "Destination change, Hawthorne, HHR." The only response is likely to be "Roger."

A tip on asking for advisories: remember the person on the other end is often very busy, even if you don't hear him on the air. There may be voices or sounds coming in both ears, he may be on one or more "landlines," and he's probably mentally juggling a lot of "stuff." The more professional you can sound on the radio, on that very first call, the more likely he is to accept you. On the other hand, if your first transmission or two is long, rambling, in no particular order, he is very likely to just say "Unable" to you, and "Squirrel" under his breath (this is not a compliment). One little procedure I like, that seems to work well is saying, on the initial contact:

"Good Morning, Seattle Center, N1BE, VFR Request"

This is short and sweet, and lets him know exactly what is coming. He can finish whatever he's doing, make a couple entries in the computer, then set it up for my information, and say "N1BE, go ahead".

"N1BE, a BE35/R, off Arlington, climbing to one seven thousand five hundred, VFR to LAX"

Note I didn't tell him "3.7 DME on the PAE 140 Radial" or any exact position? He doesn't need that, he's going to look in the general area, and watch for a target that changes from 1200 to whatever he is about to issue. Note also, I didn't say my current altitude, he's not quite ready for that, yet.

"N1BE, squawk 1234"

"N1BE, squawking 1234, three thousand, climbing"

Now he'll see my target change/pop up on his display, with an altitude, which he can cross-check from my words. I believe you will find yourself denied advisories far less often with this technique.

The Classic Way (aka "Navigation 101")

But, I digress, let's get back to flying "direct."

Let's start at the simplest level and do a couple of conceptual exercises to lay the groundwork. I say "conceptual," because they are probably too much work for most of us, and it is probably just easier to go airways, or VOR to VOR. Let's not let reality intrude here, we're playing thought games!

Assume you have only one VOR for navigation. With this, you're legal to file and fly IFR anywhere in the USA. True, it may not be wise to depend entirely on one radio, or to do this in high activity areas, but out in the boonies, and with radar, I'd do it. (Sure would be nice to have a handheld GPS and a handheld radio, FAA-approved or not, though!) Using, say, a Sectional Chart, lay out your "direct" course, and lay out some waypoints wherever you like. Using forecast winds, calculate your required heading and time for each leg.

Next, file "direct," get your clearance, and launch. Fly the calculated heading for the time you've estimated to your first waypoint. What radio aid are you navigating on? Nothing, just heading. I know of no requirement to have a continuous display of navigation information. Even going VOR to VOR, there is a "break" of several seconds while changing stations (he said with tongue only slightly in cheek).

About the time you expect to be over your first waypoint, take a fix, using that single VOR on two different stations, and mark it on your chart. By calculating backwards, it's easy enough to figure out your actual track, groundspeed, and since you know what your heading and True Airspeed were, you can calculate the actual average wind you've been flying in. By applying that to the course from your current position to the next waypoint, you can refine your navigation, and return to the original track. Sure, all this is a pain, but it's surprisingly accurate, and believe it or not, we used to do this all the time crossing the oceans! Any pilot can learn to do this, the main reason we had professional Navigators was because the fixes needed celestial navigation, and that takes a lot longer to learn. Besides, a celestial fix required the pilot to first get up, and then do some real work, and both are anathema to any self-respecting airline pilot!

Of course, this exercise would be a lot easier with two VORs, VOR/DME, or DME/DME. It gets better yet with something like a KNS-80, the ancient area navigation device that brought RNAV to General Aviation.

Remember, this was only a mental exercise.


There is another way to "cheat"--legally. Figure out a rough heading from your Sectionals, your computer, or even the handheld GPS, and use this terminology when IFR: "Center, request heading 140, when able, direct Key West." That also lets the controller know what you're planning. So what if you won't receive the Key West VOR for another sixteen hours? You'd be surprised how primitive the radios are in some of the airliners belonging to "cost-conscious" operators, and they use this little trick all the time.

How accurately do you have to fly these "direct" routings? Not very! Suppose the wind blows you off the direct route when ATC assigned you that "long-term heading?" Many worry about this, for no good reason. You will not get a "direct" clearance unless you are within radar coverage, so many feel "Big Brother is Watching." Well, yes--and no. Fact is, the radar controller doesn't care how accurate your navigation is, his only concern is separating you from other traffic by 3 to 5 nautical miles, or 1,000 ft. vertically. For this reason, he wants to count on you continuing to do what you're doing (heading and altitude, unless you get something different), so he doesn't get a rude surprise if he's running someone past you just 5 miles away. ATC radar is fully capable of picking up even very small deviations from a course, but unless the controller thinks you're confused or lost, he probably won't say anything if he sees you drifting off-course. Then it will be a matter of just letting you know, more or less as a courtesy. You fly the airplane, he keeps the traffic separated.

Enter the Handheld

Lowrance If we can do all that with just one VOR, or NDB, then what's wrong with cranking up a handheld GPS and smoothing out those corrections? Why not just fly the GPS, as long as the heading appears reasonable, and you make occasional (frequent?) cross-checks with a VOR, DME, NDB, or anything else (including visual fixes)?

Some go a little nuts over this, protesting "What if the GPS fails, or wanders off?" Well, what if you're navigating via VOR, or ADF, and the station, or the aircraft radio fails? If the device, whatever it is, starts calling for an unreasonable heading, a real pilot will check it out, before following it blindly. I have seen a VOR (in Europe) give gradually increasing errors (huge errors!) while flying towards it, and even with triple INS, and other fixes, and radar, it was a disorienting event. Later, we were told that the military were "spoofing," deliberately causing the errors, and had "forgotten" to NOTAM the VOR out of service! Hmm, maybe VORs need RAIM? (That's sarcasm, folks, RAIM is a method for detecting GPS problems that the FAA insists is necessary.)

ANY device can err, and cause confusion, but in my experience, the GPS is the least likely to do so, and will probably be the most obvious when it does. It is, of course, far more accurate than anything else when it does work. It is astonishing to me that the FAA will not allow any handheld GPS to be used as the primary enroute navigation device in a radar environment, when that same FAA will allow a VOR approach (or worse, an NDB approach) off a fix that is located well away from the airport. The FAA seems to be taking the overall approach with GPS that "Only certified perfection will do," while allowing (or requiring) far more dangerous things simply because it always has.

Equally amazing to me are the pilots who will go well out of their way to "navigate" via airways, even when VFR! One new GPS owner carefully programmed an entire six-hour flight into his new toy, including dog-legs! He was quite irritated when I just punched in "direct" to the final destination on my own GPS, and proceeded in that direction. The media may think there are "highways in the sky," but I don't. In fact, I get quite testy when ATC tries to put me on airways for their own convenience, and I will usually cancel IFR, if conditions permit (and do an inflight refile later, if needed). It would be silly for a boat to go from buoy to buoy and it's just as silly to go over VORs when there is no need to.

This is also a good time to point out that VORs are "choke points," where lots of airplanes DO "come together." Hopefully, not fatally. Did I mention that going VOR to VOR costs more money, more time, and more fuel? That it could make the difference between making an unneeded stop, or not?

There are some other considerations, however.

MEA and Terrain

GPS195 Pilots are always responsible for terrain clearance. Even on airways, even when being radar vectored, the penalty for "attempted penetration of granite" is instant death. During the NTSB hearing the controller may be very sorry he let you do it, and he may even get some blame if he made an error, but the pilot and all occupants of the aircraft pay the price. Never, EVER forget this. You must ALWAYS know where you are, and where the terrain is. The number one rule of flying is "Don't hit nuthin'." (Next is "Don't do nuthin' stupid.") Alas, if people would only follow those two rules we could get rid of the FAA and most of the FARs.

How do we determine and maintain MEAs when going "direct" (or any other time, for that matter)? Simple, use those gorgeous Sectional Charts! The non-informative IFR charts can be left in the bag, because the Sectional has all the information you need, far more than the IFR chart. Not only that, they are beautiful works of art, a pleasure to look at, and use--far more "character" than those barren IFR charts. By doing this, you have terrain information right at your fingertips and a whole lot of additional potentially life-saving information, too. By keeping a running match between the airports on your moving-map display and the sectional, you have continuous knowledge of landing spots. By looking ahead, you can make deviations that may put you over less-hostile terrain, or more hospitable airports. By looking at the actual terrain levels, and the MEF (Maximum Elevation Figure) in each quadrangle, it's easy enough to add 1,000' (2,000' in mountainous areas) and come up with a safe altitude. You must absolutely do this when off airways, just as faithfully as you check MEA on airways (you DO that, don't you?).

In short, the Sectional Chart keeps a much higher level of "Situational Awareness" going, which is a very good thing. Pretty soon now we'll have cheap, color, high-resolution moving maps and then we'll be able to stuff the Sectional in the flight bag, too.

There also exists something of a "safety net," in that controllers are required to keep you at or above MEA (Minimum Enroute Altitude), MIA (Minimum IFR Altitude), or MVA (Minimum Vectoring Altitude), whichever is appropriate. They do a superb job of this, perhaps even too good, but don't let that lull you into any sense of security. Remember, it's an automatic death penalty on this one.

Special Use Airspace

Again, technically, the pilot is responsible for avoiding Prohibited Areas, Restricted Areas, MOAs, and Class A through D airspace. However, I'm willing to turn over a bit more responsibility for this (than for terrain) to ATC radar. Their Order 7110.65L (Air Traffic Control Handbook) mandates that they keep track of SUAs and not let either IFR traffic, or traffic on VFR Advisories penetrate any "hot" areas. The simple fact is, pilots have no easy way of knowing when most of these areas are "hot," or whether they will get cleared through them. Unless I know the area is always hot (Groom Lake, Area 51, Dreamland), I just file and fly direct until ATC tells me I can't, then I "negotiate" the best routing I can get. For the big ones, I ask well in advance, so I don't end up flying right up to them, then making a giant turn to go around.

The Garmin 195 allows a particularly neat trick from the moving map page. Merely move the cursor forward along your course line with the four-way button, and you can get a perfect idea of all SUAs that are coming. If there does happen to be something out there you need to avoid, just move the cursor to a point that will bypass it, push "WPT," then "Enter," and you have a new course to fly.

While all SUA just goes away when IFR, Class B airspace is something of an exception to the above when VFR. You must not assume anything with Class Bs while VFR, even with advisories. For Class B airspace, when VFR, you must hear the magic words "Cleared to enter the Class B." No exceptions, please.


GPS moving map screen Some pilots will inadvertently drift off a VOR radial, then rather than correcting back to the desired course as their CFI taught them, they'll re-center the needle, and head for the station, again. This is called "homing," and it is a very bad thing, really sloppy airmanship, and probably takes away points from your score in heaven. In fact, you may get to visit heaven (or the other place) earlier than you intended if you make a habit of this.

But, I've also seen people deviate around weather (or SUA), or receive vectors for traffic, then return to the original GPS course with a fairly sharp intercept heading. This is entirely unnecessary, and does not increase those points. Punch in a new "direct," and follow it, getting a clearance when IFR for "Present Position Direct <Destination>." You may have heard ATC telling someone "When able, direct to <wherever>?" This is exactly what they mean, a nice new direct course, the shortest distance from wherever you ended up. It's not cheating when it's deliberate.

It's A Valuable Tool

In short, that handheld GPS that the FAA seems to hate so much is a very valuable tool in the cockpit, even when IFR, and should be fully used for situational awareness, and to some degree, for navigation. As with all devices, it should be cross-checked by other means.

Be careful, up there!

...John Deakin

John DeakinJohn Deakin is a 33,000-hour pilot who worked his way up the aviation food chain via charter, corporate, and cargo flying; spent five years in Southeast Asia with Air America; and joined Japan Airlines 31 years ago, where he is a 747 captain. He also flies his own V35 Bonanza (N1BE) and is very active in the warbird and vintage aircraft scene, serving as an instructor in several aircraft and as an FAA Examiner on the Curtiss-Wright C-46 and Martin 404.

This document was last updated on 29-Nov-1998. Copyright 1998 AVweb Group. All rights reserved.