This is the first of what promises to be a lengthy series on IFR/GPS. Given that GPS technology and equipment have been around the better part of a decade, the series may seem a bit overdue, but, as you will see, there have been delays in achieving workable and broad-based applications. This in turn has meant that technical pieces have been somewhat limited, forced to concentrate on single manufacturer solutions rather than general technique.
In the early 1990's the FAA passed the word: the King is dead, long live GPS. From this, we were to understand that satellite-aided navigation was ready for widespread implementation and that the FAA would soon cease all VOR support.
Even for the government, it was a prediction that turned out to have a very flexible timeline. The initial FAA enthusiasm was understandable: abandoning the nation's VOR stations would translate into big savings in maintenance costs. Embracing GPS, at least at the level of non-precision approaches, would mean virtually no cost at all: the hardware is fully supported by other branches of government.
Alas, it was not to be. Almost fifteen years down the line, we still lack a coherent GPS program capable of attracting widespread IFR use. In English: very few General Aviation (GA) pilots use GPS for IFR flight.
The primary barrier to widespread use is predictable: cost. The huge majority of aircraft in the GA fleet were built and equipped before GPS was approved; it takes quite a lot of money to do the refit.
Unfortunately, even in aircraft equipped from the start with the right stuff, there remain some other significant obstacles to IFR/GPS. Over the next couple of months, I hope to reduce their apparent severity somewhat
In the late 1990s, two major original equipment manufacturers (OEM), Cessna and Piper, began to lead the way toward GA installation of IFR approved GPS: from1997 forward, the units became standard equipment in planes rolling off their production lines. Problems developed fairly quickly: in one notable instance, the user interface was difficult, prompting widespread concern that competent single-pilot IFR ops might require as much as 40 hours add-on training.
Upgraded equipment addressing some of these concerns soon became available, and in the long run, these early difficulties will inevitably be shrugged off as teething pains.
Another problem, however, has proved more difficult to resolve: manufacturer idiosyncrasy. Each GPS user interface from each manufacturer is different, a situation that continues to cause roadblocks.
While it is possible to identify broad functions and procedures common to all GPS units, individual manufacturers continue to provide access through different patterns of button pushes and knob twists. In a useful analogy, it's as if VOR instruction required at some point the investment of three or four hours to master setting the OBS on a King radio in contrast to a Narco.
There hasn't been a comparable situation in IFR navigation since industry first adopted VOR in the early 1950s. The closest one can get with "modern" equipment is the contrast between standard VOR heads and HSI's, and it makes a poor analogy: the transition between the two seldom requires more than an hour to master.
Since modern GPS units are more computer than radio, it is most appropriate to compare the current GPS situation to the world of PCs, where Mac users are baffled by Windows and Linux, Windows fans won't even admit the other two exist, and all are viewed with contempt by Unix pros.
In the hands of the unwary, the variety of GPS user interfaces has dangerous potentials for IFR flight, where prompt and accurate access to navigation data is of critical importance.
The fault that led to the confusing variety in GPS units is rooted in the hands-off approach adopted by the FAA in initially certification of GPS units. From the beginning, the Administration told manufacturers what to do, but not how to present it. This has led to a confusing array: as an example, a pilot comfortable with a Garmin 430 may well require more than 5 hours ground and flight to reach a similar level of expertise on a Honeywell unit.
From the start, flight schools and individual CFIs faced some tough financial decisions: most CFIIs don't arrive with solid GPS skills and in consequence need substantial upgrade training before they can be let loose on the public. The variety of user interfaces poses a formidable problem: should CFIs and customers be trained on version A or B? If you choose A, how do you get utility when a B airplane is added to the fleet? Perhaps you should concentrate exclusively on planes equipped with A. But wait: what if that manufacturer now switches to B--or conceivably, C?
So, on the training side, progress has lagged: training departments and individual CFIs are still struggling with the transition, and even today, seven years after the first "new" Cessna singles were introduced, few schools are actually prepared to provide ab initio IFR/GPS training. Although there are exceptions, when GPS training is given, it is usually placed in the "advanced" category: add-on material for pilots initially trained in conventional VOR/LOC/DME disciplines.
The lack of a standardized user interface has also slowed the development/adoption of flight training devices ("simulators"), placing further barriers in the path of widespread GPS training.
A second group that has had to wrestle with the GPS transition is the designated pilot examiners (DPEs): the folks who give FAA checkrides.
According to FAA rules, applicants showing up for instrument checkrides must be capable of using all installed navigation equipment: if there's DME on board, they can be asked to use it. Same for a GPS. If the examiner asks for a GPS procedure and the applicant cannot perform, it is grounds for disqualification, so it is reasonable to assume that applicants with GPS equipment will have been trained in its use.
The prospect of using GPS on checkrides puts a fairly heavy demand on DPEs. It's probably obvious that examiners have to be GPS competent before asking applicants for GPS procedures, and that their competence has to extend to whatever GPS equipment is installed in the aircraft flown. So here again, there is substantial need for upgrade training, to include, at the minimum, the King (now Honeywell) 89b, 94 and the Garmin 430 and 530 units (soon to expand to include the Garmin 1000, as well). Whew.
Here's a work-around adopted by some: DPEs can, but are not required to ask for GPS procedures, even when available. Provided that other aircraft equipment can be used to make one precision and two different non-precision approaches, GPS can be left out altogether at the discretion of the examiner. So this scenario becomes possible: an applicant who has a GPS unit must train to use it, but may not be asked to demonstrate competence on the IFR checkride.
Based on an informal survey in my area, fewer than one in ten IFR checkrides given today include any GPS navigation at all. In most cases, there is no GPS installed, in others it's an examiner choice, and finally, some applicants opt to present themselves with expired data bases, neatly ducking the entire issue.
So far, I've explored two interrelated stumbling blocks that have slowed the transition to GPS: expense and consistency of design. I'm sorry to say there's at least one more.
The issue that has every school really hopping is the added time needed to teach IFR students how to perform on both standard VOR and GPS. It's an issue that may well be moot in ten years, but for now, you cannot ignore the fact that a comprehensive IFR program has to prepare graduates for both options. This in turn promises to add hours and expense to IFR training--at a time when flight schools and students alike have been tightening belts and trying to stay lean.
Of the two systems, GPS is dispensable, VOR is not. This is because the best approach system currently available, the ILS, still relies on VOR/LOC guidance, not satellites. Since applicants must prepare for ILS approaches, the flight school avenue most often chosen has been to postpone GPS training completely and concentrate exclusively on VOR/LOC/DME.
As more and more aircraft show up with OEM GPS installations, this approach is proving to be increasingly clumsy, and it seems inevitable that more and more applicants will expect to receive instruction on the newest and best equipment. In turn, this means that the overall training time required for the IFR rating will increase somewhat.
To balance the added time needed for GPS instruction, the most likely victim will be ADF/NDB instruction. The wisdom of this course will be the subject of continued debate for some time to come; I'll lay out the pros and cons as this series moves along.