Portable GPS?

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JasonCT

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I was doing some window shopping on some "portable" GPS' and got to thinking --- Why aren't any of them certified for IFR use?
For example many of the older "panel" mounts are certified for en route navigation and they have very limited capacities compared to a flight cheetah or AvMap GPS.

You can get portables with all the instrument approaches, approach plates, IFR routing, terrain avoidance, and traffic avoidance, weather, etc etc etc .... Is there certification in the future you think?

As always thanks for your comments.
 
Cost of certification VS ROI, meeting FAA requirements for accurancy and stability, why would the manufacturers want to mess with what has become a fairly lucrative market, as it is now.
 
Certification of installations gives the FAA some control over how the thing is mounted and powered, and where the antenna is placed. With a portable, those factors are all over the place.
 
CapeCodJay said:
Is there certification in the future you think?
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For the reasons stated by Messrs. Wesley and Ibold, no. But then again, ten years ago I said the FAA would never let insulin-dependent diabetics fly as PIC, so what do I know?
 
Ron Levy said:
For the reasons stated by Messrs. Wesley and Ibold, no. But then again, ten years ago I said the FAA would never let insulin-dependent diabetics fly as PIC, so what do I know?
Click to expand...

If the FAA were so inclined, I could see how it might happen. There would probably have to be an external antenna and a connection to ship's power as well as some requirements for mounting that would insure the thing wouldn't fall to the floor in turbulence and that it was easily viewable and touchable by the pilot. And those things would detract from the "portable" aspect of the unit EG you'd never be able to use it in a rental fleet. But IMO there's nothing technically wrong with the concept of an IFR approved portable (with current DB), just a strong likelihood that the "forward thinking" minds at our FAA might balk at the idea. Of course such a unit will cost considerably more than it's non-IFR siblings because of the huge NRE required for certification. Even then, I suspect that any company (like Garmin) would be reluctant to suck part of their panel mount IFR GPS market into the portable genre. It' s more likely that someone like Lowrance who doesn't have a panel mounted product would consider such a product were the FAA open to the idea.
 
If they certified the portables they would no longer sell any of the more expensive units.
 
I use a Garmin GPS V handheld for situational awareness for VFR flying. It is also good for tracking where I have been and how well various manuvers were executed. I consider it a valuable tool used with other navigation systems.

With that said, please note the attached JPEG image from my PPL practical exam- I highlighted a couple of places where the signal was either blocked or reflected such that the GPS thought it was someplace else. The plane is a C-172, GPS tucked on the instrument panel at the base of the windscreen. This is not a good thing to have happen in IFR conditions.

The wiseguys out there will likely comment on the 90° turn as a lack of my piloting prowess- if so, I claim the gap as the ability to teleport the plane & occupents:goofy:
 

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Cap'n Jack said:
I use a Garmin GPS V handheld for situational awareness for VFR flying. It is also good for tracking where I have been and how well various manuvers were executed. I consider it a valuable tool used with other navigation systems.

With that said, please note the attached JPEG image from my PPL practical exam- I highlighted a couple of places where the signal was either blocked or reflected such that the GPS thought it was someplace else. The plane is a C-172, GPS tucked on the instrument panel at the base of the windscreen. This is not a good thing to have happen in IFR conditions.

The wiseguys out there will likely comment on the 90° turn as a lack of my piloting prowess- if so, I claim the gap as the ability to teleport the plane & occupents:goofy:
Click to expand...

I don't think that the GPS thought that it was anyplace else anywhere on that chart. All that happend was that it lost signal. When it gained signal it recorded another waypoint in memory. That mapping software/gps track displays by drawing a straight line between the saved waypoints.

As far as the signal loss. That has nothing to do with the technology being unreliable. It has to do with the poor signal obtained where you mounted the GPS. I have *never* lost signal with my portable antenna that I stick on teh top of the windscreen. Stick an antenna on the outside of the airplane and it's a whole new ball game as far as signal goes.
 
Jesse-

The GPS wasn't recording waypoints or trying to go to waypoints. It was doing no "navigating" except for recording position- that "corner point" is either where the GPS thought it was or an extrapolation of position when it lost signal- this unit will add a point when it loses signal (seen when entering long tunnels and mentioned in the manual). Reflections of signal aren't unusual on the ground. The signal reflection changes the time the signal is received and causes the GPS to calculate a different position if the equations for time/distance can be solved.

As for the signal loss, it is indeed due to signal loss from where I placed the GPS and the positions of the satellites at that time. I never said the technology was unreliable. I was just saying that a hand-held GPS isn't suitable as a primary navigation system, particularly in IFR. An antenna mounted on the outside of the aircraft helps, but still requires some care in placement. As an extreme (and silly) example, placing the antenna next to the vertical stabilizer of a metal plane would probably cause the same symptoms you see in my plot. As a renter, I really can't put an antenna outside of the plane in any case.
 
The AIM has a good discussion about GPS. The main issue seems to be whether RAIM is available so that the GPS unit can let you know if the data it's getting is reliable. For example, the Garmin GNS 430 will even figure out which satellite is bad and then ignore its data (as long as it has enough satellites in view, it needs 5 to do RAIM). If it can't do that, it'll pop a message that the data is bad so you know you need to go to secondary systems.

Do any of the handheld aviation GPS units have RAIM?
 
Cap'n Jack said:
... that "corner point" is either where the GPS thought it was or an extrapolation of position when it lost signal- this unit will add a point when it loses signal (seen when entering long tunnels and mentioned in the manual).
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I don't think you should be flying through long tunnels... :no: That might get you a careless and reckless citation, at the very least. :)
 
LOL-

Everyone I see try to fly through long tunnels in movies winds up with a lot of pain- the Nazi chasing Indiana Jones with a Me-109 or the helicopter scene in Mission Impossible come to mind. With such examples, I don't think I'll try it.:no:
 
That isn't a tunnel!

All kidding aside- where is that? I've always wanted to see a natural bridge like that Now I'm in Nebraska, I have to be closer to them than I was in NJ.
 
cwyckham said:
The AIM has a good discussion about GPS. The main issue seems to be whether RAIM is available so that the GPS unit can let you know if the data it's getting is reliable. For example, the Garmin GNS 430 will even figure out which satellite is bad and then ignore its data (as long as it has enough satellites in view, it needs 5 to do RAIM). If it can't do that, it'll pop a message that the data is bad so you know you need to go to secondary systems.

Do any of the handheld aviation GPS units have RAIM?
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AFAIK, they don't have it. At least I haven't heard of it yet. My GPS V does tell me that it doesn't have enough satellites for 3D or 2D naviagation, but it isn't agressive enough at that for being a 1° aerial navigation device. It also won't warn me (as an IFR certified unit would) of bad satellite geometry. This occurs occasionally when the satellites in view line up in such a fashion that the "spheres of equal time" from each satellite become tangent to each other rather than intersecting. You can get enough satellites to satisfy RAIM, but still have a poor fix. This happens more for handhelds since a part of the plane can block satellites with better geometry.

Can hand halds be made to avoid these problems? Possibly, but I haven't heard of them going that way.
 
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NOTHING that is not permanently installed can be certified for anything.

That's good because the other side of that coin is if it's not permanently installed and isn't wired into the electrical system it doesn't have to be an approved installation. I understand a few inspectors have had that explained to them.
 
mikea said:
NOTHING that is not permanently installed can be certified for anything.
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Why's that? I'm surprised to hear that. I work on certification in New Zealand, and I believe our rules are quite similar in most respects. We routinely certify role equipment that is removable such as cargo pods or agricultural spray gear.

If you're referring only to avionics, we install gps units for agricultural use that are removable. We just have to prove that when they're installed they meet all the requirements (including things like electrical load, interference with other equipment, not shining too many lights in the pilot's eyes, not ripping off and killing anyone in an emergency landing, etc.). Part of the certification is the method of installation. So, we could certify a handheld device that strapped to the control yoke in a certain way and had a separate aerial that attached in a certain way. It would only be legal if it was attached in exactly that way. If you had it strapped on in a different spot it wouldn't be legal anymore.

The rules are a bit more stringent for IFR use, and a radio, for example, has to be on a magic list of type I devices that can be used for IFR. GPS are probably similar, but I'm not sure. Of course, it's likely that the reason that they're not approved is that reception and electromagnetic interference effects aren't guaranteed to be ok without a permanently installed antenna, but that's just a guess. I haven't worked on a GPS unit yet, so I'm not sure of the rules.

Chris
 
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