Acceptable turbulence

Peter wrote:

ATC will not refuse a request with “to avoid” and if they did or (this is not uncommon, especially if they are busy) they don’t reply, just do it anyway. They

I have only had one problem getting wx avoidance from ATC and it still troubles me years later. Heading west over the channel at FL100 ish there were a long line of connected TCUs ahead and to the right, stretching from near Southend away to the north at least 50 miles.

I asked London Control for a heading xx degrees to the south to avoid. They refused. I reiterated that I absolutely needed a diversion to the south to avoid TCUs ahead (and they were giving wx diversions to commercial traffic all around). Again they refused and said the airspace was too crowded and I would have to proceed ahead on the FPL route or divert to the north. North was ridiculous as it would have added at least 150 NM to my flight and I didnt have the fuel.

I stupidly went ahead and ploughed through the line of weather and dealt with pretty bad turbulence.

I have often wondered if I could have been even more forceful and simply said “turning xx left to avoid” and refused to comply with ATC. What would have happened?

I asked London Control for a heading xx degrees to the south to avoid. They refused. I reiterated that I absolutely needed a diversion to the south to avoid TCUs ahead (and they were giving wx diversions to commercial traffic all around). Again they refused and said the airspace was too crowded and I would have to proceed ahead on the FPL route or divert to the north. North was ridiculous as it would have added at least 150 NM to my flight and I didnt have the fuel.I stupidly went ahead and ploughed through the line of weather and dealt with pretty bad turbulence.I have often wondered if I could have been even more forceful and simply said “turning xx left to avoid” and refused to comply with ATC. What would have happened?

I had similar story in LTMA, actually, the weather was so bad that aircraft went NORDO, there was no point asking for heading or altitude anyway

I asked London Control for a heading xx degrees to the south to avoid. They refused

They can’t actually do that. You are the “captain” and you may be dead while they go home after the shift. And ATC will never be blamed in the accident report.

I had this in Germany and did what I believed (and still do) the right thing, in the face of an aggressive ATCO (I think that guy is well known) but some others will give you another opinion I had a similar aggressive thing near Bordeaux with “the military controller is very angry” and didn’t give in either (French ATC is clearly scared of their military, to the point of mostly not even wanting to talk to them) and after a bit they stopped bothering me.

Once you have an IR, you need to use it and fly VMC on top if at all possible. If it isn’t, you will probably be getting iced up anyway, and in a DA40 that will make you go only one way. So, use the IR image, windy.com cloud tops, sferics, etc, so get a picture before going. Here and search for “tops”. A lot of trips simply aren’t possible unless you can climb to FL250+, even in summer, or especially in summer when much of the European mainland can be covered in ++TSRA after mid-day.

Flying in IMC with embedded TCU/CB is a no-no in light GA. If you are VMC on top and you see smooth tops ahead then there isn’t likely to be much convective stuff inside, but if you see big lumps sticking up, the opposite is true.

Peter wrote:

They can’t actually do that. You are the “captain” and you may be dead while they go home after the shift. And ATC will never be blamed in the accident report.

Thats kind of the conclusion I have come to when I reflect back on this incident.

I have been flying IFR for about 13 years now and I learn something nearly every flight. I am now 65 years old, flying a v capable turboprop, but ATC still intimidates me sometimes.

I did have the courage to stand up for myself with London ATC more recently, and it too was a learning experience. Coming back from Croatia at FL 260, long flight into strong headwind at the limit of fuel endurance. Coming over the channel (why is it always ‘coming over the channel’??) I had an overspeed issue with my new to me turboprop and the only way to control it was to throttle further and further back. I really wanted to get back to my maintenance base, Gloucester. The headwind was 80 plus kts and I was having to slow to 140 kts TAS, and ATC refused to let me descend or go direct Gloucester. Then I remembered the magic words “pan, pan”. My god it was awesome – “N380KC, you are cleared direct EGBJ, descent and speed at your discretion”. Utterly f*cking magic!

The only problem was the embarrassment of being met by two fire trucks, a medic car and an ambulance, all lights flashing, waiting at the threshold and following me all the way down the runway.

North was ridiculous as it would have added at least 150 NM to my flight and I didnt have the fuel. I stupidly went ahead and ploughed through the line of weather and dealt with pretty bad turbulence.

Never experienced something like this in Europe.
It’s a bit of a ping pong game with ATC. It usually helps to request as early as possible and give them heading and for how long you need it.
At the moment ATC offered a deviation to the north, you could have asked them straight back for vectors to divert due to fuel. Maybe it would have yielded some compassion from them.

Generally, I think ATC really suffer.
Imagine a surgery takes place in a clinic, and all of a sudden someone walks in and says „Hey, I’m a hobby surgeon, can I join the operation?“.

They handle an endless stream of „boring“ but super professional jet traffic, in the sense that the gears of ATC and of the airliners are perfectly ground (grinding?) together after years and years , and then some weekend warrior comes along and causes some trouble by innocence. Doesn’t apply to you or any others here on the forum, but talking to ATCOS there is some cruel stuff going on out there. What happens is everyone not belonging to the „normal“ is thrown into the same „troublemaker“ group and needs to first prove that they are workable to escape again.

Buckerfan wrote:

I had an overspeed issue with my new to me turboprop

Please elaborate, do you mean prop overspeed?

SEP to SET converts have redline KIAS at the former yellow arc (Vno).

„Like all piston-to-turbine conversions……gets an airspeed redline (VNE) placed where the beginning of the yellow arc (VNO) is on the piston version.“

Easy to overspeed.

There is a lot of truth in all this, both sides. But remember this:

• There won’t be many complete muppets in GA asking for avoidance. All of them will have an IR (you can’t really get into these situations on a VFR flight; those guys just drill a hole in IMC at 3000ft into some 3500ft hill) and most will have a plane which is reasonably capable on the GA scale. Yeah; we all knew somebody who flew “Eurocontrol IFR” in a C150, and I especially recall one “huge-profile forum personality”, but they are incredibly rare, and most of the very few talk the talk rather than walk the walk. So everyone has been through the “IR meat grinder” course, and you are welcome to slag off European IR training, but that’s another topic

• The numbers are very small. I’d say 99% of the “muppets” are VFR-only pilots, because that bit of GA is 100x more accessible. You don’t even need any understanding of how an engine works, what the mixture does, etc. Also most IR holders who actually fly anywhere real are outright owners, which narrows down the numbers even more, and this is no news to anybody hanging about in the GA IR scene: you could fit most of Europe’s active IR population into one big room. You could easily do a 700nm fligh across Europe and hear maybe 1 other light GA plane on the radio.

• While we “amateurs” might be maxed out at FL180 at ISA+17 and can’t just outclimb the lump ahead (even if ATC let us suddenly climb, which often they wont because they need to coordinate ahead) so we need an “avoid”, the “professionals” are flying hardware which in any altitude where a “conflict” with light GA might happen can do +3000fpm even with 150 fat [insert your favourite junk eating country] aboard. This means they can not only outclimb stuff but probably already have done so long ago if they were in the same sector. It is very tempting to say to ATC “do the job you are paid for” although I have never seen a need for that in the UK (great service today EIWT-EGKA). If you have an active TAS (TCAS1) and can see nobody within say 20nm and +/-3000ft, then knowing this system does show jets (decent transponders) with ~100% reliability, it is a fair bet that somebody is just being lazy.

• ATC usually don’t have a wx picture (in Europe) but they might “get help” like this. A few German speakers translated the sound track (privately, of course). It is obviously right to ask for avoids early but they may not always believe you.

• Mostly we are nowhere near big jets. The Eurocontrol route generation system ensures this. Keeps us away from terminal areas (ATC does that too, very pro-actively) and enroute we are obviously nowhere near.

Snoopy wrote:

Like all piston-to-turbine conversions……gets an airspeed redline (VNE) placed where the beginning of the yellow arc (VNO) is on the piston version.“

Easy to overspeed.

I know that, but as you know airspeed very easy to control by lowering the gear, closing the throttle and/or reducing the amount of decent, this is why I think that Buckerfan was perhaps referring to prop overspeed, but as the Jetprop has a propeller control this should also rule that out, so why would he fly to a maintenance base because of too much airspeed?

Lowering the gear when you hit a bump during descent? Too late… overspeed happened in a split second.