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What If 100 People Had A Gpsr On A Plane?


halhal

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I've read quite a few of the discussions about having a GPSr on an airplane.

 

I know the power is very low and that it is an individual airline and pilot decision on being able to use one. The common sense is to follow the airline rule but it is generally considered safe if no rule can be found.

 

But suppose the airline says it's fine to use a GPSr on the plane and then 100 people show up and turn on their receivers. Would having that many receivers being on have a potential problem with the onboard electronics of the plane? Is this perhaps a reason why the airlines say "no" to using our GPS on the plane?

 

Hal Huntley

(halhal)

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All consumer electronic devices must be designed so as to not interfere with other electronic devices. If a device is malfunctioning, the possibility exists that it will cause interference. The power used by a GPSr is very small. It wouldn't be enough to do anything to a closed system (the aircraft). If all 100 units were malfunctioning, there might be enough collective power to cause a minor disturbance. The likelihood that all 100 devices could malfunction at the same time is so small, it isn't worth considering.

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Also, there is no restriction on Laptops, PDAs, etc. The difference with GPSrs is that they have an antenna. AM/FM radios are also banned, because in the event of a malfunction, could possibly use that antenna to send out interference.

Actually, most airlines ban ALL consumer electronics on take off and landing, because even laptops and pda's put out interference. Just ask any ham or shortwave listener who has a computer whqt varied interference even a properly funtioning computer can cause.

Edited by Mopar
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Who would hide the first cache made out of the mealbox and containing tasteless food, plastic fork, barf bag, folder on what to do when you gonna scream "HEEEELP!" when the plane are crashing, hot tissue roll with lemon smell, a stolen pin from the steward with a plane on and finally: a handgrenade that someone found under the seat that the under-paid sleeping security staff at the airport missed...

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Also, there is no restriction on Laptops, PDAs, etc. The difference with GPSrs is that they have an antenna. AM/FM radios are also banned, because in the event of a malfunction, could possibly use that antenna to send out interference.

Actually, most airlines ban ALL consumer electronics on take off and landing, because even laptops and pda's put out interference. Just ask any ham or shortwave listener who has a computer whqt varied interference even a properly funtioning computer can cause.

Yes, but Laptops and PDAs are allowed in-flight, radios are not (AM/FM, cell phones, GPSrs, etc)

Edited by Team GPSaxophone
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Um...I flew back from Spain to Philly with my GPSr in the window from somewhere just north of Portugal to Atlantic City, NJ. Nobody complained and I learned that my flight path took me close enough to see my freakin' house's location in Boston (where's a parachute when you need it). I also got to see my GPSr record a 700+ mph *legitimately*.

 

I even took digital pictures of Boston, Cape Cod, Martha's Vineyard, and what I originally thought to be Providence (I haven't cached there yet to have any waypoints).

 

In case you were interested in seeing them.

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Here's what I did (since my arm tired after the first few dozen miles)....

 

First, I was seated in the inner aisle seat...but they told me the flight was under-booked so I was welcome to take a seat by myself since I was travelling alone. I sat in the window seat with the tray down. I stuffed the blanket and 2 pillows between the tray and the window. Up against the window I was getting sub-50 ft accuracy and about 5 satellites (remember, they'll all be out the same 90-100 degrees of skyview...). On the tray, I was barely getting 3 satellites and a 200 ft accuracy...and when I dropped 1 satellite, I'd lose a lock on my position completely. So, I struck a happy medium (cause i couldn't figure a way to keep it stuck to the window) and propped it up on the pillows and blanket between the tray and window. 3-4 satellites and about 70 ft accuracy.

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Probably one reason they like to ban GPS from airlines is so you can't see how far out of the way they've taken you, while you are running behind schedule.

Actually, it was kinda neat to see my tracklines overlap as the plane was in a holding pattern. We flew the same oval 3 or 4 times!

Edited by Stunod
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There would be 50 Garmin owners screaming "we're going to crash!" and 50 Magellan owners saying "Why does my GPS say I'm in Iowa when I can see O'Hare out the window?"

I hate to post just for the sake of posting since I have nothing really to contribute to this topic . . .

 

However . . . that REALLY cracked me up!! Hehe!! :D

 

Happy caching and stuff!! :o

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29083_12100.gif

 

This is the flight back from Detroit. I generally had a 4 or 5-sat lock when I took readings every 10 minutes, starting at 5:00 p.m. with the first one closest to Detroit (#1):

1. 373 mph 22,500' @ N42 22.659 W-84 08.375

2. 465 mph 31,163' @ N42 27.411 W-85 29.631

3. 477 mph 35,106' @ N42 13.325 W-86 49.892

4. 416 mph 35,203' @ N41 57.696 W-88 04.786

5. 416 mph 35,714' @ N41 39.703 W-89 26.187

6. 418 mph 35,813' @ N41 20.993 W-90 45.731

7. 414 mph 35,335' @ N41 03.625 W-91 55.226

8. 411 mph 35,410' @ N40 44.086 W-93 10.008

9. 415 mph 33,551' @ N40 24.144 W-94 22.602

10. 415 mph 35,435' @ N40 03.118 W-95 35.675

11. 415 mph 35,452' @ N39 40.804 W-96 49.691

12. 418 mph 35,454' @ N39 18.478 W-98 00.488

13. 418 mph 35,476' @ N38 55.100 W-99 11.572

14. 420 mph 35,483' @ N38 30.370 W-100 23.736

15. 414 mph 35,533' @ N38 01.086 W-101 45.568

16. 411 mph 35,532' @ N37 27.893 W-103 02.289

17. 414 mph 35,443' @ N37 06.480 W-103 42.759

18. 407 mph 35,325' @ N36 39.450 W-104 49.132

19. 414 mph 35,229' @ N36 14.789 W-105 55.668

20. 417 mph 35,195' @ N35 48.703 W-107 03.614

21. 413 mph 35,177' @ N35 22.342 W-108 09.863

22. 453 mph 35,170' @ N34 54.413 W-109 18.868

23. 493 mph 28,956' @ N34 25.877 W-110 35.308

24. 298 mph 11,742' @ N33 52.671 W-111 25.062

Edited by TEAM 360
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lets see 30828 feet, max speed 481mph, 76" accuracy, 379 mph average I guess my Garmin was on. They pilot announced that we will be flying at 31000 ft, what a liar...........lol

 

I hope they got a handle on that discrepancy before they landed!

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lets see 30828 feet, max speed 481mph, 76" accuracy, 379 mph average I guess my Garmin was on. They pilot announced that we will be flying at 31000 ft, what a liar...........lol

 

I hope they got a handle on that discrepancy before they landed!

 

I think the pilots are flying using barametric altitude which varies slightly from what is showing on a GPSr.

 

Hal

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But suppose the airline says it's fine to use a GPSr on the plane and then 100 people show up and turn on their receivers.  Would having that many receivers being on have a potential problem with the onboard electronics of the plane?

 

No.

 

Is this perhaps a reason why the airlines say "no" to using our GPS on the plane?

 

No.

 

Hope that helps.

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Also, there is no restriction on Laptops, PDAs, etc. The difference with GPSrs is that they have an antenna. AM/FM radios are also banned, because in the event of a malfunction, could possibly use that antenna to send out interference.

Actually, most airlines ban ALL consumer electronics on take off and landing, because even laptops and pda's put out interference. Just ask any ham or shortwave listener who has a computer whqt varied interference even a properly funtioning computer can cause.

Yes, but Laptops and PDAs are allowed in-flight, radios are not (AM/FM, cell phones, GPSrs, etc)

at the risk of posting a real response, AM radios have internal oscillators that radiate a lot of RF noise. SO much so that in the old days(pre-FM rock stations) you could cause someones AM radio to not receive by placing a pocket am radio on the other side of the wall and tune it 455kHz down from the station they were listening too. The interference from the portable radio would be strong enough to interfere with the IF circuits in the other radio and cause it to only produce static for that one station.

 

Yes I know I am an OLD Geek if I can remember doing that to someone. However please remember that this was before Video Games and the INTERNET. We were bored.

Edited by CO Admin
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Also, there is no restriction on Laptops, PDAs, etc. The difference with GPSrs is that they have an antenna. AM/FM radios are also banned, because in the event of a malfunction, could possibly use that antenna to send out interference.

Actually, most airlines ban ALL consumer electronics on take off and landing, because even laptops and pda's put out interference. Just ask any ham or shortwave listener who has a computer whqt varied interference even a properly funtioning computer can cause.

Yes, but Laptops and PDAs are allowed in-flight, radios are not (AM/FM, cell phones, GPSrs, etc)

at the risk of posting a real response, AM radios have internal oscillators that radiate a lot of RF noise. SO much so that in the old days(pre-FM rock stations) you could cause someones AM radio to not receive by placing a pocket am radio on the other side of the wall and tune it 455kHz down from the station they were listening too. The interference from the portable radio would be strong enough to interfere with the IF circuits in the other radio and cause it to only produce static for that one station.

 

Yes I know I am an OLD Geek if I can remember doing that to someone. However please remember that this was before Video Games and the INTERNET. We were bored.

I had no idea you were into electronics, CO.

I take back all those mean nasty things I said about you :lol:

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Also, there is no restriction on Laptops, PDAs, etc. The difference with GPSrs is that they have an antenna. AM/FM radios are also banned, because in the event of a malfunction, could possibly use that antenna to send out interference.

Actually, most airlines ban ALL consumer electronics on take off and landing, because even laptops and pda's put out interference. Just ask any ham or shortwave listener who has a computer whqt varied interference even a properly funtioning computer can cause.

Yes, but Laptops and PDAs are allowed in-flight, radios are not (AM/FM, cell phones, GPSrs, etc)

at the risk of posting a real response, AM radios have internal oscillators that radiate a lot of RF noise. SO much so that in the old days(pre-FM rock stations) you could cause someones AM radio to not receive by placing a pocket am radio on the other side of the wall and tune it 455kHz down from the station they were listening too. The interference from the portable radio would be strong enough to interfere with the IF circuits in the other radio and cause it to only produce static for that one station.

 

Yes I know I am an OLD Geek if I can remember doing that to someone. However please remember that this was before Video Games and the INTERNET. We were bored.

I had no idea you were into electronics, CO.

I take back all those mean nasty things I said about you :lol:

Wow, the you might have to worship me when you find out that I used to work for Sony Broadcast R&D back in the old days. (Pre CCD cameras) When we used 3 Plumicons or Saticon tubes to make Cameras for Studio and ENG work.

 

dadgum I am OLD.

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Also, there is no restriction on Laptops, PDAs, etc. The difference with GPSrs is that they have an antenna. AM/FM radios are also banned, because in the event of a malfunction, could possibly use that antenna to send out interference.

Actually, most airlines ban ALL consumer electronics on take off and landing, because even laptops and pda's put out interference. Just ask any ham or shortwave listener who has a computer whqt varied interference even a properly funtioning computer can cause.

Yes, but Laptops and PDAs are allowed in-flight, radios are not (AM/FM, cell phones, GPSrs, etc)

at the risk of posting a real response, AM radios have internal oscillators that radiate a lot of RF noise. SO much so that in the old days(pre-FM rock stations) you could cause someones AM radio to not receive by placing a pocket am radio on the other side of the wall and tune it 455kHz down from the station they were listening too. The interference from the portable radio would be strong enough to interfere with the IF circuits in the other radio and cause it to only produce static for that one station.

 

Yes I know I am an OLD Geek if I can remember doing that to someone. However please remember that this was before Video Games and the INTERNET. We were bored.

Wow this is old hi-tech geek. All we could think of was to swipe the garage door opener and drive around town looking for others on the same frequency. Dad never could figure out why the batteries wore out so fast...... :)

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:D Uh.. If the altimeter on the 60cs is barametric, how does it read the correct /or nearly correct altitude of an airplane with a pressurized cabin? Is there someway of getting GPS altitude only? And by the way, since the pressure of the cabin is less than sea level, what altitude is the pressure in the cabin set for?

 

Just wonderin..?? :blink:

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I had my Garmin Vista held up against the plane window for a large portion of a recent cross-country flight. It worked slick as snot, and no-one expressed any concerns at all. It was pretty cool to see exactly where I was, and how fast I was going. The barometric altimiter got confused, I think, because the plane was pressurized. The barometer clearly showed when the plane pressurized itself, and the calculated altimeter showed frightening rates of descent/ascent!

Another interesting thing was that our route was not a straight line on the map, but gentle curve, reflecting the actual shortest route on a round planet, instead of the square map.

I even had good sat. reception for the vast majority of the time!

There was a lot of stuff to look at in the Garmin, and it really made the long trip more interesting.

Ian

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:D Uh.. If the altimeter on the 60cs is barametric, how does it read the correct /or nearly correct altitude of an airplane with a pressurized cabin? Is there someway of getting GPS altitude only? And by the way, since the pressure of the cabin is less than sea level, what altitude is the pressure in the cabin set for?

 

Just wonderin..?? :blink:

I dont know how it works on the 60 cs, but my etrex vista lets you do it just about any way you want. You can get a pure gps altitude, or one corrected with barometric readings, etc etc. You can view the barometer, or calculated altitide individually. I usually leave it in the auto-self-correct mode.

 

I dont really remember what the cabin pressure was doing.. I was more interested in watching my position on the map, and finding places I knew.

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;) Uh.. If the altimeter on the 60cs is barametric, how does it read the correct /or nearly correct altitude of an airplane with a pressurized cabin? Is there someway of getting GPS altitude only? And by the way, since the pressure of the cabin is less than sea level, what altitude is the pressure in the cabin set for?

 

Just wonderin..?? :o

I don't know this for sure and I am positive that once this is said, someone will correct me, but I seem to remember that cabin altitude is generally in the 6-8 thousand foot range.

 

I think the pilots are flying using barametric altitude which varies slightly from what is showing on a GPSr.

 

In general airplanes flying above 18,000 feet in the US set their barometric altimeters to a standard pressure of 29.92 inches. I am not sure what that converts to in millibars. Other countries use a different altitude for that reset. Below that altitude the airliners will use the barometer reading from the destination airport. Given the standard barometric pressure setting the actual altitude of the aircraft will likely be different from the reported altitude. This is done so that all airplanes will be using the same settings and their altitude has a common reference with other aircraft in the area.

 

I hope that satisfies your curiosity.

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I'll try to answer some of your questions.

 

Above 18,000 we use 29.92 in Hg as the altimiter setting. That way when the pressure changes (and it does all the time) all the planes are using the same setting. Just imagine if two planes were to cross 1000 ft from each other and they were using different altimieter settings they could get too close.

 

The cabin altitude should max out at 8,000 ft. In between takeoff and cruise it is climbing or descending slowly to/from that altitude.

 

On 9/11 the hijackers all used handheld GPS units to find their targets. It was said that they even went to the twin towers before hand to mark them as waypoints so they could find them.

 

As for interference, personally I do not think they are a problem. The only thing I have seen that causes interference is Nextel phones. For some reason if they are left on there is interference with the intercom of my plane. Like someone else said, I think it is best to not allow them while low just in case.

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Probably one reason they like to ban GPS from airlines is so you can't see how far out of the way they've taken you, while you are running behind schedule.

Actually, it was kinda neat to see my tracklines overlap as the plane was in a holding pattern. We flew the same oval 3 or 4 times!

My brother (Air Trafic Controller) shared this with me:

 

A plane had circled the airport twice due to congestion. Pilot radios in request to land... again. Controller responds 'negative' and issues command to circle again. Pilot says "Son, do you realize it costs $1000 every time I turn this plane around?" Controller responds, "Roger. Give me $2000 worth."

 

-T

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