Is there a difference between how commercial jets and GA aircraft use airways?

Question

In the answer to this question about why people use airways, one of the commentors pointed out that GA aircraft often use airways in a different fashion than commercial aircraft. I couldn't tell from context why this is true though. Is it laziness, spite, lack of knowledge? Or is it simply that GA aircraft are instructed to use them differently? Or, even, is it that GA aircraft are typically at a lower altitude so they simply have different airways?

Why do GA aircraft use airways different than large commercial planes?

Answer 1

In Europe, some airways are only available in certain flight level ranges, so a commercial airliner and a GA turbo-prop travelling from the same departure airport to the same destination airport could be travelling on different routes due to airway restrictions in place and the inability of one aircraft to climb to the same level as the other. Below the routing for PC12 operating IFR at FL150 and an A320 operating at FL250.

(FPL-DEXAM-IG
-PC12/M-SDE1FGHIJ1RWXY/LB1
-EDDL1000
-N0160F150 KUMIK L603 KOSEK Z74 HAREM T104 ANORA
-EDDM0150 EDQT
-PBN/A1)

The above flightplan from EDDL to EDDM validates for FL240, but anything above FL245 will not pass, it will error out with:

PROF195: KUMIK L603 KOSEK DOES NOT EXIST IN FL RANGE F245..F999
PROF195: KOSEK Z74 HAREM DOES NOT EXIST IN FL RANGE F245..F999
PROF197: RS: EDUUFFM14 EDUUFUL13 EDUUNTM13 EDUUTGO13 EDUUSLN13 EDUUWUR14:F245..F255 IS CLOSED FOR CRUISING REF:[EUROED41A] ED AIP(ENR3.3 1 NOTE 9)

To fly the same flight in higher levels, you would need another routing:

(FPL-DAXAM-IG
-A320/M-SDE1FGHIJ1RWXY/LB1
-EDDL1000
-N0260F270 DODEN Y853 BOMBI T104 ANORA
-EDDM0150 EDQT
-PBN/A1)

This routing works fine for anything above FL245, below it would again error out with:

PROF195: BOMBI T104 HAREM DOES NOT EXIST IN FL RANGE F000..F245
PROF204: RS: TRAFFIC VIA DODEN Y853 BOMBI IS ON FORBIDDEN ROUTE REF:[ED2318A] Y853 DODEN BOMBI
PROF205: RS: TRAFFIC VIA DODEN Y853 BOMBI:F000..F245 IS OFF MANDATORY ROUTE REF:[ED2318B] Y853 DODEN BOMBI
ROUTE135: THE SID LIMIT IS EXCEEDED FOR AERODROME EDDL [EDDL50120A] CONNECTING TO DODEN

Answer 2

It depends on the type of aircraft, and the operational support behind the airplane.

In the Western US (as I would expect is also true for Les Alpes), the terrain is quite high, and there is sparse radio coverage at lower obstacle-clearing altitudes. Lighter aircraft will opt for Federal Airways, which have a Minimum Enroute Altitude that ensures obstacle clearance, and radio navigation aid and voice communications coverage.

Carriers have huge flight operations departments, which plan the routes taken by their aircraft. Since carriers have scores of flights in the air, they are constantly adjusting routes for traffic and weather, and may file routes that a smaller operator wouldn't consider

For smaller operations, there are "Preferred IFR Routes" published in the A/FD (see below). They can also obtain one-off or subscription flight operations from companies like Jeppesen, which give them the resources of a large flight operations department.

Answer 3

There are variations in how particular airways are used, but there are not routes that are restricted based on the type of operation here in the US, or anywhere that I know of.

As others have pointed out, there may be various restrictions on an airway (route) such as altitude, times of use, directions of use, etc. but they apply the same to GA aircraft as a commercial aircraft.

Keep in mind that GA encompasses a wide variety of different types of aircraft, including aircraft that have far less and far more capabilities than commercial aircraft. Saying that a particular airway is restricted to aircraft flying above 18,000 feet does not restrict it to commercial aircraft, and the entire system is based on a first come first serve concept.

Answer 4

GA encompasses a huge range of aircraft operations, some of which look a lot like airlines and some which don't. For instance, a student at a flight school is very different from a private jet. That said, most GA operations are VFR in small, low, slow planes.

While it varies by country, VFR aircraft are generally not required to file a flight plan nor, in most airspace, even talk to ATC. You can just get in your plane, take off, and for the most part, simply fly wherever you feel like, whether that is sightseeing around town or crossing the country.

Similarly, even if you do talk to ATC, it is a lot easier for ATC to keep planes separated if they're moving at 100kt rather than 500kt. So, they don't need much ability to predict where you're going because they have time to just watch and see.

Also, small aircraft have a much wider range of performance and mission profiles, from training to crop-dusting to pipeline patrol to cross-country flights spread across thousands of small airports, whereas jets are generally all trying to fly at the same optimal altitude for as long as possible between a handful of medium to large airports.

All of these factors combine to result in airline (and to a lesser extent charter jet) operations end up needing a lot more work to keep them from bumping into each other. Airways (and things like SIDs and STARs) help ATC manage that complexity.

Answer 5

"GA aircraft" covers a lot of ground. A private pilot out on a VFR cross-country cruise would typically elect to not use airways at all, at least in the US. Why go where the other traffic is concentrated?

Answer 6

Commercial and GA often do use different airways near their respective airports, but when at cruising altitude, you may find GA and small turboprop flying on the same airway, at the same altitude. For example, a small regional Q400 flying from Toronto to Ottawa might be assigned at FL220, and since most GA aircraft are capable of that, it is possible that they can be flying on the same airway, at the same altitude. However, it is a different case when they are near their respective airports. Some GA airports close to large commercial airports have height restrictions and the GA planes are made to follow different airways because of wake turbulence, airway congestion, etc. But lots of times, you can also find GA planes at big airports! For example, Vancouver Intl. has a 2 main runways, and another shorter one for small GA planes.

So basically, GA planes can have different airways, but it depends on the location, altitude, noise abatement procedures, radar capability, airport size, airspace capacity, and many other factors.