Primarily for general aviation discussion, but other aviation topics are also welcome.
By riverrock
FLYER Club Member  FLYER Club Member
#1853089
Ibra wrote:My understanding VFR clerances under Radar Control Service to CTR, CTA & TMA do not allow one to enter ATZ, most Radar ATC or Procedural Approache ATC will ask you to switch to Tower ATC for further ATZ clearance

It's up to the individual unit, whether they coordinate it for you. You may also find the same controller is doing tower and approach.

I have no clue about the difference between CTR and CTA - if I'm cleared then I'm cleared
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By johnm
FLYER Club Member  FLYER Club Member
#1853093
This sort of thing really annoys me as does being "dumped at Detling " there's really no excuse for it, though I have a little bit of sympathy for controllers as the dog's breakfast of airspace design and ATS is not of their making.

Given that Farboro' now have controlled airspace does "dumped at Detling" still occur or is there an orderly handover for IFR arrivals at Fairoaks or Blackbushe??
By Mike Tango
#1853099
matthew_w100 wrote:I did the M40j2/Burnham/Ascot route the other day. I was cleared unambiguously, with a VERY unambiguous clearance limit of Ascot Racecourse. Being naive I was expecting an onward clearance before I got there, but heard nothing. So as I approached I made a position call. And was told to "call Farnborough, goodbye". So now what am I supposed to do? Orbit in Heathrow's zone till I can find a gap in Farnborough's radio transmissions? Carry on towards Woking, and call F'boro as soon as I can? As far as I was concerned, I'm now in controlled airspace without a clearance, and the infringement course is beckoning.


I’m only guessing, but I suspect there may be an agreement between TC Thames/SVFR (they look after the London Zone during the day) and Farnborough that traffic looking to also transit Farnborough CAS won’t be cleared past Ascot without either coordination or transfer to Farnborough. I think part of the London Zone is actually delegated to Farnborough in that area.

In which case though the r/t should be something like ‘hold at Ascot, for onward clearance contact Farnborough on…’, or if coordinated ‘you are cleared to enter Farnborough controlled airspace, after Ascot route…, contact Farnborough on…’

Ambiguity does no one any favours. I’d strongly encourage challenging ambiguous r/t or clearances immediately on the r/t, for both your own protection and to subtly point out to the controller that they should putting a deal more thought into what they are saying. There’s no excuses for it from the ATC side.
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By akg1486
#1853106
Ibra wrote:For VFR you have to clarify with a ATC for next handover before reaching zone boundary or ask to change frequency, I
learned this the hardway, stuck at airspace boundary between Murcia & Alicante and between Cardiff & Bristol, in both cases, I got cleared hastly into airspace before getting thrown out of airspace on 90deg turns while going down like a brick...

I get the feeling that most VFR pilots aren't aware of this. Under IFR, the controller shall keep track of necessary future clearances, but under VFR it's up to the pilot to request a frequency change with enough time to reasonably expect to get the next clearance or time to take evasive action. It may vary depending on where in the world you are, but where I've flown (including a big piece of continental Europe) the ATS-unit giving you service normally prompts you to change. But if they don't, it's up to you.
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By rikur_
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#1853111
OP sounds a bit like requesting a MATZ transit and getting a response of 'Your MATZ transit is approved, not below 3000ft' ..... i.e. your MATZ transit isn't approved, you'll have to go over the top.
akg1486 wrote:Ibra wrote:
For VFR you have to clarify with a ATC for next handover before reaching zone boundary or ask to change frequency, I learned this the hardway, stuck at airspace boundary between Murcia & Alicante and between Cardiff & Bristol, in both cases, I got cleared hastly into airspace before getting thrown out of airspace on 90deg turns while going down like a brick...

I get the feeling that most VFR pilots aren't aware of this. Under IFR, the controller shall keep track of necessary future clearances, but under VFR it's up to the pilot to request a frequency change with enough time to reasonably expect to get the next clearance or time to take evasive action. It may vary depending on where in the world you are, but where I've flown (including a big piece of continental Europe) the ATS-unit giving you service normally prompts you to change. But if they don't, it's up to you.

I wasn't aware of the background on this. I was aware of the inconsistency that some days I'll get handover to the next unit, others get asked to freecall, and occasionally asked if I want a handover.

Leads back to a previous question - as a pilot is there any benefit of requesting a VFR transit, as opposed to an IFR transit?
By TopCat
FLYER Club Member  FLYER Club Member
#1853112
Fellsteruk wrote:I guess that and a sky demon or similar log is your only proof if nats come knocking :(


flybymike wrote:It’s “the man” from the CAA who comes knockin’. :(


For the record, a Sky Demon log is not deemed to be such proof.

I had to prove that I hadn't infringed a few years ago, and although I was ultimately successful, the man from the CAA told me to my face (I had a chat with him subsequently at the LAA rally) that the GPX files can be faked, and that was why he wasn't interested in my SD log as evidence, despite it exonerating me completely.

Ironically, the only thing that was accepted was something that could have been faked a damn sight more easily, but that's another story.
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By Dave W
FLYER Club Member  FLYER Club Member
#1853114
TopCat wrote:I had to prove that I hadn't infringed ...

Sigh.

I get the impression it is rather more reasonably handled now, but that's still quite shocking to read.
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By akg1486
#1853120
rikur_ wrote:Leads back to a previous question - as a pilot is there any benefit of requesting a VFR transit, as opposed to an IFR transit?

Since I don't have IR-privileges, I don't have the luxury of choice. But controlled airspace and clearances are made with CAT (IFR) in mind, in particular when going from one controlled airspace to another.

The only disadvantage I can think of is if ATC wants all IFR traffic to follow specific routes and therefore making an IFR transit unnecessarily long. But I don't know for a fact if that's the case.
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By rikur_
FLYER Club Member  FLYER Club Member
#1853121
thread drift....
Out of interest, what is accepted as proof for altitude?
I've noticed that our Skyecho and transponder are often 200ft different, more with the DV open (for reasons I understand).
In theory mode C is calibrated, so I assume that's treated as 'correct' but it doesn't take much to make a small difference on static pressure.
If it's alleged that you've vertically infringed by 200ft, how does anyone 'prove' you have or you haven't?
By johnm
FLYER Club Member  FLYER Club Member
#1853122
Separation is often about altitude and needs a thousand feet apart for IFR and 500 ft seems to be OK for VFR which is why in France airways semi-circular rule has 1000s for IFR and VFR slots in between layers at 500 ft separation.

A controller will give QNH and then seek confirmation of altitude and expects a reading from the altimeter.
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By PeteSpencer
FLYER Club Member  FLYER Club Member
#1853124
akg1486 wrote:
rikur_ wrote:Leads back to a previous question - as a pilot is there any benefit of requesting a VFR transit, as opposed to an IFR transit?

Since I don't have IR-privileges, I don't have the luxury of choice. But controlled airspace and clearances are made with CAT (IFR) in mind, in particular when going from one controlled airspace to another.

The only disadvantage I can think of is if ATC wants all IFR traffic to follow specific routes and therefore making an IFR transit unnecessarily long. But I don't know for a fact if that's the case.


When I flew to Welshpool from E Anglia last week for lunch with @grahamB.
I was on a ZFPL which weaved me across Birmingham zone on entry to CAS.

However the moment I entered CAS at EBOTO Bham radar transmitted 'Entered controlled airspace, radar service, cleared direct Welshpool' thereby avoiding multiple course changes/possible altitude changes.

Controller couldn't have been more helpful and unambiguous: In fact he was even apologetic that he had to keep me at FL100 for longer than expected due to departing traffic.

Having got me through CAS he descended me and gave me a traffic service as far as Shawbury, who then 'traffic serviced ' me around the various rotaries and hills till Welshpool appeared through the showers right on my nose.
Excellent service.
Excellent lunch, thanks @ GrahamB

Peter :wink:
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By Mike Tango
#1853126
akg1486 wrote:The only disadvantage I can think of is if ATC wants all IFR traffic to follow specific routes and therefore making an IFR transit unnecessarily long. But I don't know for a fact if that's the case.


The disadvantage of requesting an IFR clearance if it's a VMC day is that standard separation then applies between all IFR traffic. (In theory anyway) fewer aircraft fit into one piece of airspace if they are all IFR than if there is a mix of VFR and IFR.

If you take the London Zone Ascot - Burnham route as an example, to transit that way IFR at a terrain safe level you'd almost certainly have to stop either the arrivals or departures to Heathrow and Northolt as applicable for a period of time.
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By akg1486
#1853127
PeteSpencer wrote:Controller couldn't have been more helpful and unambiguous.

That sort of sums up more than 99% of all my encounters with controllers and other ATS! :thumleft: Any new pilot who reads this thread may think the opposite, so it's important to remember that the person on the other end of the radio is your friend.
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By TopCat
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#1853128
rikur_ wrote:If it's alleged that you've vertically infringed by 200ft, how does anyone 'prove' you have or you haven't?

It's a good question.

Things not accepted:

  • The fact that after being based at White Waltham for 20 years and knowing the LFA regs, and OHJ at 1300 procedure (now 1200), it's a bit unlikely I'd randomly bowl up in the overhead at 1800'. Obviously I could just forget.
  • The fact that on a flight the next day Farnborough confirmed my Mode C was overreading by 200'. Which would be on the tapes. But obviously I could have been lying to them about my indicated altitude.
  • My SD log, which didn't exceed 1500' on the eastern side of the ATZ. But obviously I could have subtracted a few hundred feet from all the height readings in the GPX file. While being careful enough to gradually subtract less than that nearby, to ensure no altitude discontinuity.
  • My verbal assurance to The Man from the CAA. Obviously I could have been lying throughout my detailed written report and phone 'interview'.

Thing accepted:

  • A report from my avionics guys after benchtesting my Mode C, confirming that it was overreading by 200', and my altimeter underreading by 70'. Which had to be sent directly from the avionics guys, thus making it completely impossible to fake.

Thank fark it wasn't a fault intermittent enough to not show up in the testing. But intermittent faults aren't a thing, are they?
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By rdfb
#1853136
rikur_ wrote:Leads back to a previous question - as a pilot is there any benefit of requesting a VFR transit, as opposed to an IFR transit?


A few issues come to mind, which is why I haven't yet done it despite having an IR(R):
  • On an IFR clearance I'd be expected to enter IMC as required by the controller's routing. That might mean that I can't switch back to VFR when leaving CAS. Flying IFR OCAS is very difficult. There are terrain avoidance issues (because of CAS above), navigation issues (can't use SkyDemon for navigation IMC, and typical IFR navigation equipment is hard to set up and operate, especially ad-hoc in-flight, such that I have course guidance that avoids CAS), and challenges rerouting if denied a planned transit. This means that if I haven't planned IFR OCAS in great detail, I don't want to end up in a situation where I'm IFR OCAS, and that's a risk accepting an IFR transit.
  • I have to consider the freezing level, which is often lower than where the controller might want to route me, so that has to be negotiated.
  • For a flight primarily OCAS, I often have to be lower than the terrain safe level, and therefore probably lower than the controller's minimum vectoring altitude. So IFR in CAS but VFR OCAS would often mean level changes that would also have to be negotiated.

None of these apply if I'm certain to remain VMC of course.