Long time lurker, first time poster.
Having flown on my IR(R) for the past 10 years, I’m currently working through the CBIR TK with Caledonian Advanced Pilot Training (capt.gs) (big plus of this school is the groundschool element was completed over 8 hours on a Saturday – no time off work required).
I plan to train with Rate One. I am currently evaluating whether to train in our group Cirrus or use the ATO’s TB20, and will have a taster lesson in both.
Our home-based IRI has asked me to plan an airways flight from North Weald (EGSX) to Gloucester (EGBJ).
I have an Autorouter account and that is giving:
EGSX N0148F100 NEPNA DCT DET N57 LAM DCT CPT EGBJ
That’s a significant detour to the south east, only to route back on oneself. I presume that is required to get sufficient height to get into the airways in the London TMA.
Are there any routing tricks I am missing here? Is it possible to route direct BNN, airway to CPT then the L9 until you peel off for EGBJ?
I’ll provide a brief summary of my UK CBIR training once it’s complete – hopefully by the end of April. There are already a number of helpful write-ups on here from UK posters and I don’t propose to duplicate those, but just provide relevant updates e.g. groundschool flexibility, change in exam answer format (the UK CAA now has some freetext answers in its question bank, and the EASA QB itself is being revised annually in respect of approx. 2000 questions).
One of the 4 options which Autorouter presents me with is a very short VFR leg on departure to rejoin IFR at LAM VOR:
EGSX N0169F040 LAM/N0169F040 IFR DCT CPT EGBJ
That is only 99 NM instead of 152 NM.
Did you see this on the results page after hitting “Autoroute”? Autorouter always prefers IFR flights to Y or Z ones with a VFR portion, but in this case it seems to be a significant saving by accepting a very short VFR leg. As I’m not UK based I can’t tell you how you would go about to get the clearance for the London TMA, which has a base of 2’500 ft there. The best option would certainly be to have a number to call on the ground, but these aren’t officially published anywhere AFAIK.
Edit: After choosing that “VFR to IFR” option, I can then edit the flight plan (with the little pen icon next to “Route:”, which is easy to miss) to make it an “I” plan and the following routing still validates OK:
EGSX N0169F040 LAM DCT CPT EGBJ
I don’t really see either why this isn’t proposed by the Autorouter in the first place. May have to do with the performance profile which theoretically doesn’t allow a climb to 4000 ft in such a short distance if you fly it direct.
But that is not what our friends in the UK call an “airways routing”, which was the task here.. 
Also, I guess autorouter also always tries to find an airways routing. For non-airways IFR FPLs, one really does not need an autorouter…
Generally, for low-level airways routings, one has to accept huge planning overheads in the UK. The UK Lower Airways system is simply not made for that. In some areas of the UK (along the English east coast, parts of Wales, the southwest of England, and in the north of Scotland) it is totally inpossible to fly “airways” in the lower airspace – because there simply are no lower airways there.
Looking in the SRD spreadsheet in reverse and then playing around a bit, an “airway” routing could be N152F090 DCT BPK DCT BNN DCT CPT L9 MALBY
Plotting the above route as a picture
it makes it clear you will never get to fly it, whether it validates or not. There are some LTMA crossing routes at FL090/100 IIRC but ATC won’t let SEPs cross London anyway (probably OK above FL200).
In terms of higher altitude IFR, say FL100, that sort of route is normally flown a bit further north, or south (more or less at the coast) due to LHR and LGW traffic. Otherwise they will keep you OCAS at 2400ft
I would fly it VFR, OCAS, in IMC as necessary. Obviously any entry into IMC makes it IFR but in UK Class G you can change as you wish, non-radio.
I would fly it VFR, OCAS, in IMC as necessary.
When will you finally stop writing this stuff? We know what you mean, we know the point you want to make, but writing it like this remains wrong and doesn’t do justice to the knowledge you have.
Flying VFR does simply not imply being uncontrolled and flying IFR does not imply being controlled. They are simply two separate rulesets. Both VFR flights and IFR flights can be both controlled as well as uncontrolled. It simply depends on which airspace class you are in. Just being uncontrolled and IFR does not “effectively” make it a VFR flight.
You left off the 2nd half of that sentence
That is how it works in the UK. If you hold the IMCR or the IR, you can call up “request VFR departure…” at a Class G airport, and enter cloud almost immediately. The change to IFR is done inside your head only.
It’s a great system, which most of mainland Europe thinks is lethal. The stats show it is very safe, and it is the best way to get around the UK, on these kinds of short legs which the OP posted. Obviously not in low level icing conditions, and not comfortable in typical summer stratocumulus.
Certain German pilots posted here that it works the same way in Germany too, but the IMC doesn’t officially exist before the MRVA or some such 
What might be a very valid Q would be to ask: how would you actually fly a bizjet on that route?
I reckon ATC will treat a +3000fpm to +5000fpm aircraft totally differently, and let you climb straight up. I was once in a CJ4 which did a short leg at FL190 and it was revealing to say the least how different the treatment was. It seems clear that the perceived much better ability to merge in with big jet traffic is a key factor, which light GA cannot fulfil.
The Eurocontrol routing might however be the same in both cases.
