ForeFlight (merged thread)

I have never tried this from North Weald; maybe someone here can comment more directly on what works. But…

The route across London will never be flyable in a SE aircraft, due to the glide-clear rule. It also interferes with Heathrow traffic.

But lots of non-flyable routes validate via Eurocontrol. You can file them but the result, imposed by ATC, can be “remain outside controlled airspace” and with no further help, which leaves you with a tricky VFR nav job while keeping you below CAS, probably at 2400ft.

I suspect this is the same problem which the Autorouter encountered (I was a beta tester for it); in its early days it did the same thing as this. It generates routes right across London, from Biggin Hill. In the end they incorporated the SRD (standard route document) and that largely removed the “obviously silly” routings. I don’t know whether the SRD is machine-readable. This was an issue in various countries; not just the UK.

It would be really interesting to know what ATC will do with you on the first two legs of that route

In the past they would just keep you OCAS i.e. at 2400ft etc until you were past abeam Gatwick. There are some LTMA crossing routes at FL090/100 but you probably can’t climb fast enough. I have just asked a CJ4 pilot who flies perhaps 500hrs a year and he says departing Biggin they would keep you at 2400ft, then 4000ft until almost at LYD. Although, obviously, if OCAS, you could shortcut that long detour to LYD.

But… I have just tried the old and largely non-working tool; FlightPlanPro, and got this

(FPL-NxxxAC-IG
-TB20/L-YGSR/S
-EGSX1000
-N0172F110 LAM DCT CPT Y321 PEPIS Q41 ORTAC
-EGJA0109
-PBN/B2D2 DOF/180628)

That one is much more likely to get you a climb to ~ 5000ft, because you are not initially interfering with the London airport traffic. I have had lots of transits around CPT c. 5000ft, north to south.

I don’t think that route came from Skydemon – unless they now do IFR routings and signed up with the Autorouter… have they?

From North Weald EGSX normally you’ll be sent on track detling then probably keep on a SE direction for a while until allowed to go SW (likely well after passing the Gatwick EGKK centreline)
You might also have to stay OCAS for a while, and even in CAS you’ll be kept fairly low, especially on westerly landings at EGKK

On the twin you will be offered the same routing (not over London)

Thanks Noe; that is what I thought.

There is a really big problem with this, for bizjets, which (a) fly quite fast and (b) can’t see much out of the windows and (c) flying the SID etc and getting vectors are working like one-arm bandits and aren’t looking out anyway. What seems to happen is that you do get a climb into CAS (which gives you a lot of protection from the usual non-transponding GA) but only into the bottom 1000-2000ft of it. With modern high-perf climb and descent profiles for big jets, the traffic is way above you.

But you don’t get ~FL100.

Coming out of Shoreham, I have never got FL90+ until south+east of SFD.

If I was filing “some route” I would prefer mine, via CPT. Both are equally crap (in the “missile alley” sense) if you are kept OCAS.

Peter wrote:

I don’t think that route came from Skydemon – unless they now do IFR routings and signed up with the Autorouter… have they?

Ye that was my mistake: the second image was an AutoRouter generation (changed the tag).

So to my understanding the suggestion for FF in this scenario would be to rule out certain “silly” routings by incorporating the SRD database that Peter mentions?

Peter wrote:

I don’t think that route came from Skydemon – unless they now do IFR routings and signed up with the Autorouter… have they?

Isn’t everyone getting a bit excited about nothing on the routings. Surely the point of the auto routing function of any programme is to get a flight plan from origin to destination accepted by Eurocontrol.

That flight plan is almost never what is actually flown, either the controllers send you a different way or you ask for changes to save track miles whilst en-route?

I agree, but at the same time ATC are entitled to expect you to fly the filed route, so if you filed something totally crap, it might be a hostage to fortune

Also there is a big difference between the two above route examples (one down to LYD and the other to CPT) in terms of

• distance flown
• exposure to the nontransponding “civil liberties” crowd which is densest in the below-200ft band, and the LYD route is worse for that
• possible exposure to hazardous weather
• comfort; flying at 2400ft on a hot summer day is very bumpy; I well remember someone’s wife puking up in the back seat of his plane, while 4400/5400ft (still OCAS) is a lot better, whereas the route down to LYD has been well buggered up by the Southend CAS grab unless you fly way out over the sea

One also needs the ability to tune the route to avoid regions on strike – see the French case above. Sometimes only a VFR segment will work but at other times (for example EGKA-LIRJ) you could route equally east or west of Paris.

There’s certainly a value in getting a route you are more likely to fly (or closely fly, as 100% never happens):
- Planning (one of them being fuel) / Getting more reliable ETAs
- Having the points pre-loaded in your system and making directs easier

When creating a route in autorouter, under advanced parameters there’s an option called ‘avoid open waters’.
Does that have any effect ?

No idea, but it was apparently requested by some people. One can achieve it by throwing in some fly-by waypoints. A rare though good case is e.g. Shoreham to Malmo which can be flown like this

or out over the water, which is pointless. But I did that manually, by selecting KOK and SPY etc as fly-by waypoints.