Does a Ground Speed gauge for cruising exist?????

[Guest xoio]

We all know that the autopilot can be set to keep to a specific airspeed or Mach number. But has anyone created a gauge that can sustain ground speed whilst cruising??? It would be most helpful if one did, as depending upon the windspeed & direction, the same airspeed can result in vastly different speeds over the ground... Which at the end of the day is what is most important, when trying to meet an E.T.A.If such a gauge exists, does it allow to be-preset into the 000's (Thousands) of knots? & where to download from?If no such gauge exists, which SDK needs to be understood to build such a gauge. It does seem feasible for such a thing to exist, as taxi-speed gauges have already been built that can keep a constant speed irrespective of the wind & dir.. but of course these are for rolling on the ground, but the principal seems the same?Look forward to your answersAl.

[Guest]

its within FS2K2Just tune in any local VOR, and a ground speed is calculated.Depends on where it shows up on the panel, but if you tune in NAV1 in the default 734 panel, and have the ND set to NAV, it will come up in the upper right portion of the ND. If nothing is tuned, it will show --- kts.Hope that helps

[Guest metamarty]

The speed shown is the speed relative to the VOR, so it's only usefull if you're flying straight to the VOR.

[Guest xoio]

Josh, thanks for the reply,But i think you missed my point...I'm after a gauge that will function similar to a taxi speed gauge, in that it will allow for the CONTROL of the speed of the aircraft over the ground, & keep that constant, irrespective of what the air direction & speed is. So it will function kind of like an extention to the autopilot.Put simply, imagine a gauge where you enter for example: 550 kts as the ground speed you want the aircraft to keep flying at. The gauge also has to have the flexability to go into the thousands of knots.Al.

[Guest GalacticCowboy]

As you mention, air speed and ground speed are relative. Therefore, if you could somehow configure your plane to maintain a given ground speed, under certain (fairly common) conditions it could actually cause your plane to fly outside of its "envelope" and crash. Either that or the software would be intelligent enough to refuse.For example, let's say that your plane is traveling at .8M (IAS) and you have a tailwind. So your ground speed is, say, 575mph. You dial that into your gauge and your plane starts maintaining 575mph gs. Now the wind changes to a headwind. In order to maintain 575mph your plane attempts to accelerate through 1M and breaks up.All aircraft have both recommended and "do-not-exceed" speeds, and they are expressed in IAS. Trying to use a different set of speeds or expressing the speeds in different terms is a recipe for disaster.The reason it works for taxiing is because the speeds involved are nowhere near the operating limits of the aircraft. Further, since you're actually "connected" to the ground, measurement of your true ground speed is relatively trivial.

[Bearracing 3]

Al,Kurtis Miller pretty much explained why a "cruise control" based on Ground Speed is not possible nor very practical, but if monitoring your ground speed would help, you can use your default GPS for this function.Bear!

[gosta 0]

Hi Al,maintaining a set ground speed would be a disaster waiting to happen. If you encounter a strong headwind, you'll probably go into overspeed, while running into a strong tailwind could lead to a stall. Especially at high altitude you only have a very small IAS or Mach window within which to operate safely, so depending on the weather, your gound speed will differ greatly. The only way to make sure you stick to your ETA is to do it as the real pilots do - plan your flight using the wind forecasts and choose your route and altitude accordingly.Cheers,Gosta.http://hifi.avsim.net/activesky/images/wxrebeta.jpg

[Tabs 2,790]

Yeah the only constant you really want to fly by is indicated airspeed. That's aqll that matters when you're talking structural limits of the aircraft and such. Concievably, you could be flying backwards over the ground witha strong enough headwind for example, but to the plane, it doesn't know the difference between that and flying forward over the ground in a calm wind situation.

[Guest]

Switch IAS to TAS in FS options - and use existing Autopilot. That's as close as you'll get I think.ChasW