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KevinAu

What do US airlines use as far as FMS/GPSs for particular aircraft?

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What US airlines use GPS and which ones use the FMS? Any aircraft that don't use these devices?

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A bit of a odd question really. This is like asking "which houses use television and which ones use a television with a electrical plug?".The FMC is exactly what it means, flight management system. The simple autopilot in FS9 can be considered an FMC. In aircraft that are equiped with the larger airline type FMC systems, GPS may or may not be part of the FMS (system). The FMS can get information from many sources, including INS, IRS, Loran, Omega, Radio plus a myriad of other devices (of which GPS may be one of them on that list).More to your question though, most (not all - airline option) newer larger airline aircraft do utilize GPS (along with the other nav sources). However, I would venture to say that more than half of the large airline/cargo aircraft flying today does NOT have GPS (as the average age of the fleets exceed 10 years). I would further think that of those, about a third does not have an FMS (with its associated FMC, CDU, ect...) beyond that of simple autopilots.hope this helps a bit

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From the way you phrased you're question, it sounds like you are under the impression that a GPS and an FMS are the same thing. They're not. A GPS tells you where you are but that's all it does. And FMS like those on big airliners is a full fledged computer that does a lot more than keep track of your position (like a GPS) and fly the airplane (like an autopilot). The primary advantage to having an FMS is fuel management. When a big airliner flies across the country, every extra drop of fuel it has when it lands is extra unnecessary weight that it had to expend fuel carrying. So, if you severely overestimate how much fuel you need for a flight, you end up not only carrying the extra fuel, you end up burning more fuel to carry it. And of course if you underestimate fuel you can't make it all the way to your destination. When an FMS is programmed with T/O weight and wind speeds aloft etc. it calculates how much fuel the plane needs to carry. You might never have thought of this, but an airliner is refueled at every single stop. And if the flight is almost empty, they don't fill the tanks all the way up. That's be a big waste of money. Once airborne, the FMS keeps track of fuel flow rates and airspeeds in order to ensure that the aircraft doesn't exceed the fuel consumption target.Airlines want to save as much money as they can and fuel management is one of the best ways of doing it. Theoretically they'd want to get as close as they can to having the plane run out of fuel right as it rolls up to the gate. Though obviously they do always carry a ten percent reserve. On long flights, an FMS is certainly the best way to do that. For very small, propeller driven commuter planes, maybe they don't need an FMS.So to answer your question, if any of the big carriers don't have an FMS in every one of their aircraft, they are probably losing a lot of money. I'm sure they all have them. As to which ones have GPS, I really don't know. I also don't think it's that big of a deal for an airline. They can navigate just fine without a GPS so there isn't really much of an advantage to having them. If a new aircraft comes with a GPS that's great. But I doubt they go out of their way to retrofit older ones. As I said, it's a business and running a business is all about saving money.

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Like others stated it is the wrong question. There are many airliners using GPS as part of their FMS.Michael J.

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These are the basic navigation methods that airliners use:1. Basic VOR/DME radionav2. FMC using radionav for positioning3. FMC using IRS and radionav for positioning4. FMC using GPS and radionav for positioning5. FMC using GPS, IRS, and radionav for positioningYou will usually find 1. in your oldest "junkjets", such as DC-9s and 737-200s. You'll find most of these kinds of aircraft at boneyards, third world countries and Northwest Airlines (j/k). These aircraft can easily be upgraded to 2.You will usually find 3. in your 80's built aircraft such as 737-300s and long haul transoceanic aircraft.You will usually find 4. in your newest aircraft built from the '90s onward and used in short-medium service, such as RJs.You can find 5. in long haul transoceanic aircraft also.

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