GPS's on Commerical aircraft

[TooLate]

Just before the crashing economy monopolized the media, I believe I heard the media mention that in order to economize the comm. aircraft industry, eliminate vectoring flight plans, and thereby saving fuel by flying direct to destinations etc, the industry should equip the airliners with GPS equipment. After I got my jaw off the floor (you mean they don't already HAVE that stuff on board!?!?!), I have wondered about the deeper implication regarding that proposal.

It has always been my assumption that the automotive industry has incorporated gadgets from the space and aircraft industry...e.g. GPS technology not the converse. IF the above is NOT true, then have they been relying strictly on transponder "transmissions" to squawk and send updated flight status data (flt #, alt, airspd, ascending/descending, depart/arr locations etc) to ground position stations...REALLY???

Can anyone here from the industry shed some accurate light on this subject so I can have my lower jaw wired back up to normal position?

Agast in the MidWest.

TL

 

[N_Jay]

They have it.
It is more about the approved uses, not the existence of the equipment.

I would hazard a guess that you will come away understanding more by reading up on it yourself, rather then asking for a an expansion here.

 

[davidmc36]

20 Plus Years in Commercial Aviation

Aiplanes have been using GPS extensively for 15 plus years. Although they are not in many cases to use it as their primary means of navigation, with things like WAAS and other correction technology it may become commplace soon to fly precision approaches and accurate navigation routes from primarily GPS. It is being done in areas that have the technology installed already and will spread as time goes on. Right now it is most common for ATC facilities to monitor aircraft by 3D radar and the Txponder simply transmits a beacon that identifies who is who. With the advent of ADS-B the transponders transmit more info such as you say, flt #, alt, airspd, position etc. and radar is not absolutely neccessary to track where they are. The ADS-B system is becoming very widespread too. On-board the aircraft the GPS, FMS and other gadgets feed info to the transponder which transmit "squits" with the info in them. With all of these technologies working together it will make it easier for them to do what the media is talking about and fly more precise routes with less separation and more direct and less flying in circles to avoid each other as they approach airports thereby saving fuel and time.

 

[immelmen]

In regard to mainline Part 121 Commercial Airliners, (ie Boeing, Airbus, McDonald Douglas), they don't use GPS during en route navigation and only recently has it been incorporated into "pos init".

What they do have is called an Internal Reference Unit. It uses ring laser gyros, provides extremely accurate position and velocity in space(better then GPS), and is used in conjunction with an FMC for area navigation on transport category jet aircraft. Only recently has GPS been slowly integrated into the newest FMS systems and then it is only to initialize/updated an IRU position while the aircraft is stationary to facilitate alignment of the gyros.

Also, ATC radar is not 3D. There is no altitude or height finding capability in the radar itself. Altitude information is relayed via the transponder from an encoding altimeter and that reported altitude is not corrected for non-standard pressure.

As for the automotive industry being ahead of the aircraft industry, not so fast. The IRU is far more accurate in sensing motion and position of the aircraft then GPS and ONE unit will cost you more then a set of new his and hers Lamborghini....My airplane has 3 of them.

The IRU/FMS RNAV direct capability has been around since the earily 80's and is now mainstream common place in the airline cockpit. Its "open skys, plan your own route" capability has always been there, long before GPS was on your dashboard.....but if you EVER think you are going to get cleared direct O'Hare, I have a nice bridge to sell ya. Its always going to be SIDS and STARS going into the lager airports. it has nothing to do with lack of RNAV navigation capability(its been there for years even without GPS), but rather the sheer volume of traffic.

 

[TooLate]

Well, davidmc36 & immelmen thank you for your reassuring information. It was just too much to believe that in this day of technodevelopment the aviation industry at large would not have these capabilities.. especially with so many nav/com satellites up there.

As naive as I sound, I suppose that it's another example of a thread of fact broadcast with the possible plan to lead the viewer to an incomplete conclusion...or it's me not listening closely enough. And, since the blurb on the 6PM news lasts all of 1-2 minutes/story, I should know by now to search further to gain perspective. But, you folks had shed a mountain of light on it for me and I thank you for taking the time to respond so completely.

It wasn't until a transPacific flight to Hawaii a few years ago and just prior to my first GPS purchase for the car, that I wondered just how we were trackable once we left the radar "range" of the mainland. Satellites and GPS, I assumed. But, as an avid "FlightTracker/FlightAware" sites monitoring aircraft positions and scanner traffic, it wasn't until we were several hours off any land mass that I recalled that most of these sites don't actually display Lat/Long in an obvious fashion...perhaps in order to decrease clutter with so many flts in the air at any moment...but the wonder of "what if" persisted along with the question of how would we be found if we had to ditch. (I was unaware of the record of the "never a successful water ditch" (until the US Air/Hudson River event).

As I note the "national view" of the FlightAware screen, I notice that flights to Hawaii seem to proceed in rows of two or three. It's so predictably obvious, that this must be by design...sort of like the grade school field trips of holding hands in twos & threes...stay together?, yes. So, aircraft must communicate via satellite bounces when so far from land masses? And, the rows are to assist in tracking functions? Is it coincidence or design that two are always much closer to each other (side to side spacing) than the third one...or just the fact that they won't be able to stay equidistant since they're in a free airspace and not on rails ?

Thanks again for the info and the indulgence.

TL

 

[poltergeisty]

Good ol' Wired... :lol: GPS Navigation Could Boost Fuel Efficiency on Oceanic Flights | Autopia from Wired.com

They must not have researched what a FMC is or TCAS.

Edit- Re-reading the article I see what they are saying now...

@TooLate: Advanced Technologies & Oceanic Procedures (ATOP)


Next Generation Air Transportation System - Wikipedia, the free encyclopedia

Edit again... Regarding FMC, You should read about them! I re-read your above post and saw thought your "jaw hit the floor" at the mention of GPS.. Flight management system - Wikipedia, the free encyclopedia

 

[TooLate]

Thank you poltergeisty. That's a wealth of information and your first citation is the report that I saw that precipitated the jaw drop. While there was a degree of certainty that ATC was more than just radar and radio, it's nice to see the responses clarifying some of the technologies that are in use.

It makes me wish I'd done more to achieve pilot status when young and before the eyesight failed so much.

Thanks again.
TL

 

[poltergeisty]

.....and your first citation is the report that I saw that precipitated the jaw drop.

That's what I thought.

It makes me wish I'd done more to achieve pilot status when young and before the eyesight failed so much.

You can always join the isle of misfits and become a sim pilot. (I live on that island btw lol)

(Another extraordinary amount of info.)
Fly Online with VATSIM.net - Virtual Air Traffic Simulation Network providing simulated air traffic control and online flying

PMDG Simulations

Wilco Publishing - Publisher of quality simulation software since 1997

 

[immelmen]

If you want jaw dropping capability, visit the Honeywell FMS page. Flight Management Systems - Boeing 757/767 - Honeywell Aerospace

I have been using them for years and still have not seen every menu page in the box. Their capabilities, especially with performance data, are amazing. I am fairly confident It could facilitate time travel if you find the right page. Now, if I find out it can cook and clean I wouldn't need my wife anymore. ....oh, and its been around for a while too.

 

[poltergeisty]

I'm very curios. Can you do a NV51 NAV data look up and see if it's there? :lol: :lol:

..I do realize Wikipedia isn't the best source of info.

 

[immelmen]

...did you see that ID somewhere or is that your best guess? what are you thinking it will return? If it is what I think your looking for it IS in the FMS database but under a different, less obvious ID. Jeppesen has some interesting contracts, therefore anything running a Jep database will have some....interesting NAV data in it.

 

[poltergeisty]

I was just curios if indeed it would show up. . NV was what is common for that area, so It's my best guess. :lol: I really don't care about the top secret stuff. I'm not a spy or anything. :lol: Frankly, I already know what goes on there. They make donuts...

I have a topic idea now..

Edit- Having done some research, I discovered that the procures are not the norm, to say the least. :lol: I do know the names now.