Airplane use

The commercial hand help GPSrs I've used when flying showed 0.0 DME when directly over an airfield or navaid. Also, remember that GPS gives straight line distance/DME readings while DME readings from navaids (VOR/DME, TACAN, etc) are slant range in which the difference gets larger the higher and farther away you are from the DME capable navaid. Think of the aircraft as being at the top point of a right triangle and the navaid station at the other end of the hypotenuse.

There have been several to comment on speed but I can't remember the fastest legitimate speed mentioned. (I say legitimate because a couple said they lost sat reception and when it came back, the unit calculated several thousand miles per hour.) My fastest was about 535MPH. I did it using my GPSMap 60CS so it was an arrow; but yes, it booked!

how do you use your gps in airplace? just turn on and select destination airport and hit go? or does it detect the speed without selecting any destination.

You don't need a destination selected. Just go to the trip info page that has speed, odometer, etc.

I am going to try tomorrow.

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The commercial hand help GPSrs I've used when flying showed 0.0 DME when directly over an airfield or navaid. Also, remember that GPS gives straight line distance/DME readings while DME readings from navaids (VOR/DME, TACAN, etc) are slant range in which the difference gets larger the higher and farther away you are from the DME capable navaid. Think of the aircraft as being at the top point of a right triangle and the navaid station at the other end of the hypotenuse.

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I was really hoping someone would reply to that particular part of my post...it's bugged me since it happened.

I was using a handheld Magellan Meridian Silver and had selected the airport as a GOTO point while in flight. The unit was not intended for aviation navigation (I knowed better ) so I was more just playing with it on one of my solo cross country flights...and making sure I didn't get too far off track. That unit also has a built in barometer, so maybe that had something to do with it? Now I'm even more curious.

We all know GPS triangulates, so with that comes an inherent 3D position, no? My new nuvi doesn't show altitude anywhere that I can find yet and my trusty old Magellan did. I'm looking forward to flying with my new toy just to see how it acts in the same situation.

Thanks for the post…anybody else have any ideas?

John

Your Nuvi probably shows it on the satellite page, as well as possibly the "Where Am I" page

But the ERP of a cell phone, GPSr and a Gameboy are totally different as you well know. I've never heard of a commercial jetliner trying to intercept a glideslope from an ipod in row 40. I know, I know...they're just not taking any chances. Probably the best for all of us.

Sounds like you had a neat job too btw!

John

It's been a long long time for me since my old groundschool days but I seem to remember that the greatest errors will be when you are high and directly over the DME ground station. In this case the DME will never read "0" because it measures from the altitude of the aircraft to the ground station. The least error will be when you are high and far from the station. Now this applies only to DME equipment. A GPS which will indicate a distance "0" when over a VOR station, but the GPS isn't using the actual VOR to determine it's position or distance to the station.

I agree. Maybe the airlines know that GPS units and Ipods are getting to be like cell phones and AHs, everybody has one. With miles of wire running through the cabin, all acting as an antenna, they may believe:
1 times unknown radiation = no problem;
300 times unknown radiation = possible problem.

Just brainstorming!

RT

I have not yet tried my nüvi in a plane, but have used my original eTrex (yellow non-WAAS) many times.

I programmed in all of the local airports so I could use it in an emergency or if I were unsure of my bearings. (Wish I had MapSource then!)

I never had any trouble with the eTrex getting a satellite lock, even in flight.

This seems really cool - I'm going to try it next time I fly!

just got back from my short trip. It was fun to watch map and where I was located. Satellite reception was pretty good on nuvi 660 with 19-25 feet accuracy. most of the time I got speed of 500+ and somehow inbetween I got 923 MPH. dunno how that happened !!!

Probably lost satellite reception for a bit and when it reacquired, it thought it had traveled a much greater distance.

I've used my eTrex Vista on planes many times, but this week I finally got the chance to fire up my c580. It was cool to see what POI I was flying near, and to see how far I was from my destination. It took a very long time to get a signal, even at a window seat, but once I got it, it was strong and stable.

I have used my GPS on the plane.....it was very interesting.

it shows elevation, speed, and if you zoom out it is pretty cool. I have put my destination in and turned the volume off and tracked the entire way....however, it is not allowed on airplanes.

Who is going to know ? I have an old Garmin III+ and I know it is PASSIVE. It doesn't transmit and as far as I know, no one would know if you're using it or not.

You'll know about it when the airplane your riding in starts heading for the ground when it isn't supposed to

From the information I have seen, the airlines that do allow the use of personal GPS, it is OK above 10,000 feet, like the other allowed electronics.

It's interesting to look at in flight and surprisingly functional. I reviewed my flight home last Thursday and was impressed with the tracking, even though I did not leave it on the whole 4.5 hours. It created a dashed line across the US that showed the route. I recorded a top speed of 606 mph going East and a rather slow 424 mph headed West. It made almost 30 minutes difference in the flight times.

Bill

It depends on the airline. Some allow it, some don't, some aren't really sure!

Paul

Difference in time was probably due to the jet stream. Fighting those strong air currents.

http://ftp.fcc.gov/cgb/consumerfacts/cellonplanes.html

http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_...

http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft

http://en.wikipedia.org/wiki/Global_Positioning_System

http://www.mobile-review.com/articles/2002/plane-en.shtml

Cell phones are probably the worst device since they transmit and increase their Tx power to search for a network. In general, it seems electronic interference could be an issue if the plane's electronics are not well shielded. Modern aircraft are well shielded. otherwise some wise guy could invent an 'EM gun' to knock planes down. That, would be bad. But, until every device can be tested in every airline configuration, use will be regulated in a 'general' manager for the common good - or avoidance of legal actions.

All electronics produce some signals.

I posted this in another thread, but it's still relevant to airplane use as I discovered this over holiday travel so I'll post it here again.

"This was the first time I've used my 660 in an airliner and I noticed that when I had it in off road mode for "as the crow flies" navigation, the magenta "vector" didn't do what I expected. Normally, with the ground and aviation GPSrs I've used, the "tail" of the vector remains "rubber banded" to the vehicle (i.e. aircraft) when a "direct to" type waypoint (destination) is selected. Not the case with my 660. For the pilots out there with IFR navigation experience, you'll recall that the aircraft "pulls" the tail of the VOR needle as that's where the aircraft is symbolically represented on the NAV, RMI, BDHI, multi-function, etc displays. The head of the needle (or vector) always points directly toward the tuned station or, if using GPS, selected waypoint. I'm not going to go into homing versus tracking (x-wind component) since that's beyond the scope of this discussion, but that's how it works. Instead the 660 pinned the "tail" of the vector to the exact spot on the ground when a "where to" calculation was made direct to the airport (in my case, KPHX aka Sky Harbor, Phoenix). When the aircraft turned off the "direct to" vector as the pilot intercepted an airway, final approach course, etc, the "tail" of the vector remained pinned to the ground and did not stay attached to the aircraft. Pretty useless. Even an off road/hiking GPS will "pin the tail" of the vector/arrow to the vehicle so you ALWAYS know the exact heading and track to take to the selected waypoint/destination. In the 660's case, it appears that if you venture off the "magenta brick road", you need to do another "where to" calculation to get the arrow back to direct from the vehicle to the selected destination. Weird."

Please do not cross post, post in one thread or the other but not both.

Miss POI

Will work only if you have it against a window , at least for my C330 garmin which i used to track my way to the Philippines. Max speed of the plane was 588 mph. Just don't set a destination or it will recalculate forever. As i believe, it is a passive device right? So you can have it on while landing and takeoff.?. (the takeoff speed of the plane was 175mph ) I still have the max speed on my gps, will try to post the pic.

Whatever... Ok, then.

I used mine on a flight once, I was sternly told to put it away. It did register about 37,000 feet and 501 mph. I used it from DFW to LAS. I probably wouldn't have been found out if I'd muted the volume first. The nuvi kept recalculating my route, loudly, before I could silence it.

That's too funny!!! When I did a route, I had it on mute, but even so, I don't think that I would have had a problem with the airline crew. Thus far, there hasn't been any issues with them. I have had some comment on it and thought it was neat.

This was on an evening flight from Seattle where the pilot was trying to make up a half hour delay... He was doing pretty well. I got this screen shot of a legitimate max speed at 650 mph.

http://www.facebook.com/photo.php?pid=256815&l=2f2ea&id=8266...

For the record I personally think siennaot1 was fine with his post that Miss Poi comments on. It was totally relevant with the discussion so I am glad she didn't delete it.

Turned it on somewhere over the Atlantic heading east. Sitting second seat from the window, got a satellite sync without problems. Showed my maximum speed as 558 mph.

Also used it on a flight from San Francisco to Dallas, without problems. Was fun to zoom way in and to see the route followed. Would also indicate nearby cities. Often wondered what those cities were below. Now I can find out.

I went to Tampa for the holidays and had a window seat for the return trip...pulled out my trusty nuvi 360 and recorded a max speed of 550mph!

http://img516.imageshack.us/img516/2701/2401rb2.png

I'm going on a trip soon on Delta, so I"m going to try and use my new Garmin. Think I should ask when getting on board or just use it and see if they say anything? Based on responses here, I will be sure my volume is down. 550 mph, here I come!

Where do you see the altitude on the 660?

How did you take screen shot while moving?

very cool speeds!

On my Garmins they have a built in feature that you enable that allows you to take a screen shot of whatever is displayed. Once enabled on the nuvi 680 I press the power button and on my 760 it is an icon on the screen.

I have TomTom loaded on my Pocket PC and I have to use a 3rd party application to get a screen shot of it. Not sure how to do it on a TomTom 720

Tap the Satellite Strength Meter in the upper left corner of the main screen.

GPS receivers are listed in the in-flight magazine as a prohibited item to use so I wouldn't bring it up. I can legitimately say my GPS is an MP3 player if asked. Although I'm not sure the flight crew will be familiar with that new hit called "Recalculating" by American-Jill. I have to remember to M-U-T-E it beforehand.

speed may be playing a factor when the GPS is trying to aquire a satellite fix.

Did you attempt to aquire a satellite capture while in motion and if so, how fast was the plane travelling?

Depending on where you are located in the air, speed of travel, weather and few other factors, the handheld GPS may or may not work. Remember, both GPS systems (aviation/automotive) are different and work differently too.

Not true for Delta! Delta is fine with them and they are listed in their magazine as a device than can be turned on after 10,000 ft. Southwest used to be the same way but changed their tune in the middle of last year.

The last time I flew Delta (3 weeks ago) the magazine didn't list GPS at all, not under OKAY or NOT OKAY. I asked the flight attendant as I was boarding and she said she'd get back to me. When she never did get back to me, I decided to go for it. Nothing was said on any of my 4 Delta flights. FYI, it is NOT okay to use them below 10,000 feet on any airline.

Admittedly, now that I think about it, it was almost 2 years ago on an American flight where I saw it in the Sky Mall magazine. I thought it was only last April. Maybe the airlines are changing their tune.

http://gpsinformation.net/airgps/airgps.htm

Dangerous? No. Illegal? If its according to that particular airlines policy, then, yes.

GPS's don't transmit, so there is no interference. Aviation comm radios work in the higher freq's so no interference there. Same with land based nav radios. One of the reasons you aren't supposed to use cell phones in flight is because you will hit several towers at once. I don't think they like that.

That all being said, I've used three GPSs, four aviation nav/comm radios, an MP3 player and a cell phone all at the same time while flying. My plane didn't crash, the wings didn't fall off, it didn't go off course, and the electronics in the plane did not go haywire. I may have strained the alternator trying to keep power going to everything, though.

Before they close the doors on the jet, I change my route calculation (Nuvi 660) from "shortest distance" or "fastest" to "off road." A few other things I do to conserve battery and reduce noise is lower the volume to 10 - 20 % and the backlight to 20%. I also turn off WAAS (although I don't know how much that helps with the battery).

My most recent flight was on American, and they do NOT allow GPS's per their magazine. Had I known before I flew, I would have chosen US Air or Delta.

For those of you having trouble acquiring satellites in the plane, you might try acquiring by a window in the lounge right before boarding. Then on the plane turn the unit on the moment that it is allowed. The closer the satellites are to where the unit last saw them the faster it will acquire them.

Worked yesterday for me - new high speed - 556mph!

My Nuvi 200 has two choices, "Where To" and "View Map". On a plane, I would just select "View Map"; as far as I know, that shows you the map, and where you are. You don't need it to calculate a route, after all. Or would that choice not record your fastest speed, etc.? If that's the case, I read on another post that pushing the switch to the right, which locks the unit from accepting any inputs, also turns off the voice. If that works on all Nuvis, it would be a way to avoid embarrassing in-flight remarks from your personal navigator.

It is fine with Delta. Weird... the last time I looked it was still in the magazine but anyhow here is the Delta link saying it is OK.

http://www.delta.com/traveling_checkin/inflight_services/con...

On my last flight while I was at the gate and in the window seat I was perplexed on how much trouble my 760 and 770 was having to lock on the satellites. It never really got a hard lock for several minutes. When I use my 680 it locks in within seconds. I also turned on my HTC TyTnII and it tracked on quickly too. Not sure what to think of that other than whatever hardware is in the 7xx it must be different than the 6xx. I was able to get a signal but it just struck me strange because I never seem to have the trouble while using it in the car.