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toby23

How safe is GPS direct to navigation?

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With the phasing out of VOR navigation and the widespread adoption of GPS navigation now in full swing, just how safe is a sky full of pilots flying 'direct to' via GPS and will jet aircraft adopt flying GPS instead of using Victor and Jet airways?

 

Victor and Jet airways ensured, together with ATC, that IFR flights were relatively organised on highways in the sky. How can GPS navigation retain that kind of separation?

To me, GPS direct to seems to be a nightmare for ATC controllers, or are GPS waypoints laid out in a logical way that ensures relative safety i.e. virtual roads in the sky?

I think if anyone, including drones, can fly wherever they want to, as long as they use GPS waypoints, wouldn't that be chaos in the skies and chaos for ATC?

 

I know that pilot has a responsibility for his and his passengers safety but flying Victor or Jet airways IFR with ATC seems relatively safe to me and manageable in a busy sky for ATC controllers.

A sky full of aircraft flying seemingly randomly around the sky seems incredibly dangerous to me.. 

 

What am I missing and what makes a sky full of aircraft flying direct to GPS waypoints safer than one where aircraft use defined airways?

 

Thanks,

Toby


Ref: https://www.smartpilot.ca/airmanship/airmanship-articles/9-airmanship/airmanship-articles/113-gps-direct

Edited by toby23

Ryzen 5800X3D, 64GB RAM, RTX 4090, Windows 10, Varjo Aero, DOF H3

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On certain region above certain flight level, Jets have been allow direct or free route for decade.

ATC still monitoring with radar or ADS-B, and route is still apply on SID/STAR

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Airliners do not use VORs for navigation at all anymore except in rare instances. GPS is far more accurate, and GPS-based RNAV enroute navigation and SID/STAR procedures have been the de facto standard for many years. Numbered Jet airways still exist, but airliners flying on those airways are using GPS, not VORs. “Q” airways are increasingly common, and those airways are 100% based on GPS waypoints.

Airliners still carry dual VHF nav receivers, but they are primarily used for ILS approaches, and as a backup means of navigation if there is a GPS outage or failure of onboard GPS equipment.

Edited by JRBarrett
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Jim Barrett

Licensed Airframe & Powerplant Mechanic, Avionics, Electrical & Air Data Systems Specialist. Qualified on: Falcon 900, CRJ-200, Dornier 328-100, Hawker 850XP and 1000, Lear 35, 45, 55 and 60, Gulfstream IV and 550, Embraer 135, Beech Premiere and 400A, MD-80.

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@JRBarrett and @C2615 Thank you, I really appreciate your comments, you've helped me understand a lot better how modern flight navigation works!

Does this mean that we should all be navigating using GPS waypoints for VFR and IFR flights?

Are 'Q' Airways even mentioned on any of the flight planning tools available and do Q Airways replace Victor and Jet Airways entirely? 

Are our IFR flight planning tools outdated e.g. LittleNavMap, Navigraph?

Thank you

PS Your cat looks amazing!

 

 

Edited by toby23

Ryzen 5800X3D, 64GB RAM, RTX 4090, Windows 10, Varjo Aero, DOF H3

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Using GPS is safer than having VOR for navigation. Why? If the airplane has the equipment to monitor it, the airplane can actually assure much higher navigational precision with GPS that it cant do with VORs.

 

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FAA: ATP-ME

Matt kubanda

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21 hours ago, toby23 said:

With the phasing out of VOR navigation and the widespread adoption of GPS navigation now in full swing, just how safe is a sky full of pilots flying 'direct to' via GPS and will jet aircraft adopt flying GPS instead of using Victor and Jet airways?

 

Victor and Jet airways ensured, together with ATC, that IFR flights were relatively organised on highways in the sky. How can GPS navigation retain that kind of separation?

To me, GPS direct to seems to be a nightmare for ATC controllers, or are GPS waypoints laid out in a logical way that ensures relative safety i.e. virtual roads in the sky?

I think if anyone, including drones, can fly wherever they want to, as long as they use GPS waypoints, wouldn't that be chaos in the skies and chaos for ATC?

 

I know that pilot has a responsibility for his and his passengers safety but flying Victor or Jet airways IFR with ATC seems relatively safe to me and manageable in a busy sky for ATC controllers.

A sky full of aircraft flying seemingly randomly around the sky seems incredibly dangerous to me.. 

 

What am I missing and what makes a sky full of aircraft flying direct to GPS waypoints safer than one where aircraft use defined airways?

 

Thanks,

Toby


Ref: https://www.smartpilot.ca/airmanship/airmanship-articles/9-airmanship/airmanship-articles/113-gps-direct

Hi Toby,

So I'll take off my flight sim hat and put on my industry rep hat.  The question you ask is being addressed in many aviation industry groups, one of which in the US is the FAA/Industry Aeronautical Charting Meeting.  It's records and meetings are open to the interested public, and the history of open and closed agenda items can be viewed here: Aeronautical Charting Meeting – (Charting Group) (faa.gov)

 

The VOR Minimum Operational Network (MON) in the US has been underway for several years, and we reduced the number of VORs in the US down to a 1960 level.  VORs and NDBs back in those times formed the airway system in the US.  These airways were organized considering the limitations of these navigation systems, namely line-of-sight, useable distances due to signal strength and frequency overlap, etc.  Today, the use of RNAV through GPS/GNSS allows airways to be constructed without these limitations.  Q-Routes and T-Routes are used to provide efficient routing around airspace constraints or terrain.  These RNAV routes often allow lower GNSS-based MEAs than are possible with VORs due to line-of-sight restrictions.  

Where terrain and airspace is not constraining, point-to-point navigation using RNAV is the most efficient means of navigation, provided you take into account terrain, obstacles, and airspace along your route of flight.  The pilot is responsible for ensuring this basic separation of their proposed route from these items.  Flight planning becomes harder for the pilot, and sometimes pilots abrogate that responsibility to ATC...wrongfully so I might add. The FAA Aeronautical Information Manual, available on line for free, provides basic guidance to pilots on how to plan and file their route with ATC.  ATC is not there to correct a pilot's mistakes. 

Today in the US, a pilot can file and fly a point-to-point route using GNSS-based RNAV without being in ATC radar contact. That was change made about 10 years ago now. ATC has to check the route to ensure that the altitude requested is at above the Minimum IFR Altitude (MIA), 4 NM either side of the proposed route.  If not, ATC will issue an altitude where this requirement is met.  Pilots can make this easier by looking at the OROCA altitude on IFR enroute charts and plan their route accordingly.  In mountainous areas, RNAV point-to-point navigation is often NOT recommended because the MIAs are higher than the MEAs on published airways.  Flying the airway can result in being able to descend to a lower altitude earlier prior to commencing an IAP.  The FAA's Instrument Procedures Handbook provides excellent guidance on this subject: Instrument Procedures Handbook (IPH) | Federal Aviation Administration (faa.gov)

As far as ATC is concerned, point-to-point, direct-to navigation does not pose much of an issue for air traffic separation.  The FAA's ERAM system, which is the backbone of the air traffic control system, monitors for traffic conflicts for routes that are entered into the system.  If a conflict occurs, the controller is altered in plenty of time to make a correction, which could include a new route, an altitude change for one of the aircraft involved in the conflict, or the use of merging traffic procedures that issue a slight temporary vector (e.g., turn left 15 degrees) to avoid the conflict. 

The primary function of ATC is the "safe, orderly, and expeditious" flow of air traffic in the national airspace system.  That's direct quote from FAA Order 7110.65, Air Traffic Control. ATC is now issuing direct-to clearance to suitably equipped RNAV aircraft most of the time.  Even if you file airways, which are still used in IFR preferred route, a pilot can expect a direct-to clearance, often to their destination airport, if preferred routing into or out of a terminal area is not required. 

I hope this answered your question.

Thanks,

Rich Boll

 

 

 

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Richard Boll

Wichita, KS

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You still need to plan your route before hand, not just hop into airplane and click that big -D->

For VFR flight, you at least need to check the weather, terrain and the airspace need to avoid, and better have a backup plan to pick up at least some visual reference just in case GPS goes wrong.

For IFR flight, you still need to filed a FPL, even if your route is XXXX DCT XXXX, that's still a route, and in most cases, at least you'll need some sort of route (with SID/STAR) to navigate though congestion areals. and most likely you'll still have some waypoints along the route, so your flightplan might look more like XXXX SID WPA Lxxx WPB DCT WPC DCT....... STAR XXXX rather than old fashion XXXX SID WPA Jxxx WPE Vxxx WPG Yxxx....

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31 minutes ago, toby23 said:

@JRBarrett and @C2615 Thank you, I really appreciate your comments, you've helped me understand a lot better how modern flight navigation works!

Does this mean that we should all be navigating using GPS waypoints for VFR and IFR flights?

Are 'Q' Airways even mentioned on any of the flight planning tools available and do Q Airways replace Victor and Jet Airways entirely? 

Are our IFR flight planning tools outdated e.g. LittleNavMap, Navigraph?

Thank you

PS Your cat looks amazing!

 

 

Any modern flight planning tool with a current nav database will definitely include “Q” airways. I should point out that these airways are specific to North America, but Europe and other areas have GPS-based airways too.

VOR as the primary means of navigation is more common in GA aircraft. 


Jim Barrett

Licensed Airframe & Powerplant Mechanic, Avionics, Electrical & Air Data Systems Specialist. Qualified on: Falcon 900, CRJ-200, Dornier 328-100, Hawker 850XP and 1000, Lear 35, 45, 55 and 60, Gulfstream IV and 550, Embraer 135, Beech Premiere and 400A, MD-80.

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I just found this video which explains Q and T Routes for anyone else interested..

 


Ryzen 5800X3D, 64GB RAM, RTX 4090, Windows 10, Varjo Aero, DOF H3

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1 hour ago, richjb2 said:

Hi Toby,

I hope this answered your question.

Thanks,

Rich Boll

Hi Rich,

Thank you so much @richjb2 for taking the time to formulate such a detailed and informative reply. I am incredibly grateful to be able to share in your knowledge. I have learnt exactly what I wanted to. I now understand how and why Q and T routes work and exist and, one of the key bits of information for me, was the ERAM system, which I knew nothing about. I imagine the CAA here in the UK have a similar system, I hope they do! It's reassuring to know that there is a supercomputer crunching filed flightplans for conflicts and, quite amazing at the same time.

Now I just need to work out how I can use my flight planning tools to plan my flights using T routes instead. I have had a look on SkyVector, Little NavMap and SkyDemon but see only the traditional Victor and Jet Airways for IFR planning. I see the GPS waypoints but not any Q or T routes. I don't own Navigraph, so cannot comment if they include Q and T routes for planning.

Thank you so much for your help and for sharing your knowledge, I am very grateful.

Toby

 


Ryzen 5800X3D, 64GB RAM, RTX 4090, Windows 10, Varjo Aero, DOF H3

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