How does one depart with 400m visbility from Cranfield or Shoreham when ATC are around given there is no instrument procedure for such departure?
Say EGKA RWY02 with the hill in front and 400m visbility without ATS, my personal plan would be: after passing runway DER and above 500ft aal, turn to track 090 to stay away from cumulusgranite…should I ask ATC to approve this while I am controlled inside their ATZ? @Peter may know about departures in clouds there
Another academic concern: there is noise abatement for RWY20 east & west which I guess does not apply to RWY02 and does not apply to IMC flying (the least of worries in 400m with the hill and antenna in front)
I am more familiar with things when ATC are not around but getting very puzzled how things work when ATC are around without procedure…I still have few doubts, if using GPS/OBS to navigate my climb what is the legal required navigation for departure RNAV1 or RNAV5? can I fly it on wet compass with Synthetic-Vision, these tend to work better for 600m visbility
Proper answers please, no “Ask the ATC”, “Ask your IRI” or this 
Brighton City Airport aka Shoreham has an Operations Manual available to residents, so hopefully @Peter has access to the OM. Perhaps they detail LVP and take off minima?
Given the 900’ obstacle close to the north of O2 (with a 6% climb gradient?) not sure what sensible airmanship recommends as SEP take off minima.
It will be good to check what LVP procedure and OM mannual says for Cranfield or Shoreham but such useful information needs to be circulated in AIP plates or Jepps plates? how does someone operating public transport in CJ4 from Germany to Cranfield does his takeoff breif? what do CPL/IR students tell their IRE during the tests before lining up?
RNP02 missed procedure goes for 011deg track, then climb to 1500ft amsl before left turn…it is designed with RNAV1 in mind and will effectively stay away from 900ft obstacle on that hill, it still too risky to my taste to be used on takeoff, it has to be executed from 0.9nm at 500ft agl before threshold (the plates even have stark warning against delaying the missed, it’s rare to have GPS missed point sitting 1nm behind threshold: MAPT << TCH in straight-in RNP is very very very rare, a very big red flag)
A safer IFR takeoff: upon reaching 500ft AAL turn track > 090 to enter the southern protected area of circling while keeping lower obstacles in the south-east under aircraft wing, will ATC let me fly this? even better, 400m takeoff with tailwind into sea on RWY20 (will ATC approve it?)
I am more curious about ATC clearance & LVP mannual element? an uncontrolled IFR departure on GPS that keeps aircraft away from obstacles in clouds is easy to construct and execute
If an instrument procedures exists for 400m RVR why they don’t publish it? this is not specific to Shoreham or UK, there are dozens of airports like this: low takeoff minima and no published departure…
I have never heard of such a manual.
There is no LPV in the UK – Brussels banned the use of the signal for LPV.
Not everything needs to be regulated. There is a thing called “common sense” or “expertise”.
I think RobertL18C means LVP (low visbility procedures), I don’t think there is much in those mannuals than what is in the plates? LVP at starts under 2000m visbility, it’s mostly about how many aircfaft max on each taxiway…while LVTO starts under 400m but that is operators mannual
400m-2000m takeoff is well within IR privileges even without ATC, it’s done by “common sense” but clearance-wise, even in CAVOK, I expect they publish an omnidirectional or some departure for ATC? what do ATC say with 400m visbility without procedure “cleared to depart at your own discretion”?
I have departed Cranfield few times & Shoreham dozen times all in good weather under IFR: you get “cleared to FL50, depart on runway heading, remain outside controlled airspace, cleared for takeoff”, I am assuming with 400m visbility things would be different: more or less prescriptive? I am happy with “cleared FL50, depart at your own discretion, cleared for takeoff”
There are several factors which dictate departure minima for commercial and private operations.
You specifically ask about commercial here.
Standard minima is 400m without LVP procedures being put in place by the airfield itself.(I don’t know if this still applies in the UK)
I think what I call standard minima is a rule, not a recommendation. I understand that before NCO for private IFR in the UK the "recommendations " for 500mRVR which could be reduced to 250m? with a centre line and I think centre line lighting but not sure on the last bit. It’s a long time ago and I am probably not current on NCO’s or especially in the UK (ANOs).
The second factor is what the airfield decides the minima should be. If it prints one, that is the one that should be obeyed.
The third factor is personal minima and/or AOC minima. That is for the PIC and his/her employer to set but it must be at or above the 2 factors given previously.
If the departure has no SID it is an omnidirectional departure. The only standard factor is that you should not turn below 120’ (I can’t remember whether that is AAL or AGL I would heve to get the books out if I were to consider doing it)
As with the take off minima any airfield restrictions take priority over standard minima.
And as they should be at or better than those restrictions any PIC/AOC should take precedent.
You specifically asked about airfields with ATS.
The AFISO or ATCO will normally own the space up to 2500ft AIUI it is usually in an ATZ in the UK and that is the upper limit of an ATZ.
So the AFISO/ATCO can refuse your request if they think it will be a hazard to security of the airfield and/or others.You are in their space. (There could be a debate here about whether or not the space is OCAS and whether or not a FISO can refuse you) This brings you back to whether your personal minima or SOP allows you to debate with a AFISO or not. My personal SOP is not to do so while flying the plane unless I feel threatened.
Outside of the airfield’s omnidirectional departure regs the PIC has total responsibility for obstacle clearance, getting clearance to enter CAS and avoiding other traffic, although the AFISO is likely to give you a heads up on the latter.
Just my 2c and it’s been more than a year now since I last flew out of a UK airport with an AFISO and under IFR before joining airways.
For minima, it’s way simpler than that: the legal takeoff minima for us is the one printed on Jepps plates and no less than 400m (it takes into account runway lights, marking and system/state minima, for an IR holder in NCO without LVTO, the absolute minima is 400m)
No clue about TKOFF MIN in AOC/SPA: I don’t own an airline and I like to stick to what I know…
gallois wrote:
If the departure has no SID it is an omnidirectional departure. The only standard factor is that you should not turn below 120’ (I can’t remember whether that is AAL or AGL I would heve to get the books out if I were to consider doing it)
There are no omnidirectional departures in Cranfield or Shoreham, I am not sure if it’s obvious but I will let you double check
This is the elephant in the room: omnidirectional departures are 1/ published in the plates 2/ you need ATC clearance for it, it’s not something the PIC is allowed to invent when ATC are around ? in EGKA & EGTC even ATC are not allowed to put you on one if it’s not published and approved by NAA !
gallois wrote:
The only standard factor is that you should not turn below 120’ (I can’t remember whether that is AAL or AGL I would heve to get the books out if I were to consider doing it)
120m you mean?? omni in PANS-OPS is not less than 400ft AAL (120m or 394ft to be precise), France does implement such rule but UK, even adds more to it: omni is not less than 500ft AAL…again that is the minimum for the turn, when omni is published with obstacles around, it has an altitude that keeps RNAV1 & MOC, at Pontoise it’s 1400ft AMSL not 800ft AMSL (400ft AAL) !!
gallois wrote:
So the AFISO/ATCO can refuse your request if they think it will be a hazard to security of the airfield and/or others.You are in their space. (There could be a debate here about whether or not the space is OCAS and whether or not a FISO can refuse you) This brings you back to whether your personal minima or SOP allows you to debate with a AFISO or not. My personal SOP is not to do so while flying the plane unless I feel threatened
Why they can’t write that on the plates? or you mean you may depart or not as “c’est a la tete du client” (depending on who you are)? let’s stay away from personal SOP discussions, let’s keep it about legalities & practicalities
gallois wrote:
Just my 2c and it’s been more than a year now since I last flew out of a UK airport with an AFISO and under IFR before joining airways.
It’s not UK specific, you have the same problem in LFFK low takeoff minima but there is no omni departure published for Fontnay (again not sure if it’s obvious, so worth double checking), however as there is no ATC, one tends to do as you said “the PIC has total responsibility for obstacle clearance, getting clearance to enter CAS and avoiding other traffic”
So on takeoff you have to do-it-yourself departure (I know you hate doing this but you still do it), I am still curious what do you say in takeoff brief? how you fly and when do you start turning?
Sorry to be pedantic but my 2c, it seems you are missing the whole point that you are flying in clouds without published departure (it’s not an issue if you have ‘expertise’ or ‘common sense’ but I am seriously worried if you fail to notice that and simply depart in white or blue not knowing where to turn and when to turn)
NON-PRESCRIBED DEPARTURE ROUTES
At many aerodromes, a prescribed departure route is not required for ATC purposes. Nevertheless, there may be obstacles in the vicinity of some aerodromes that have to be considered in determining whether restrictions to departures are to be prescribed. In such cases, departure procedures may be restricted to a given sector(s) or may be published with a procedure design gradient in the sector containing the obstacle.
OMNIDIRECTIONAL DEPARTURES
Where no suitable navigation aid is available, the criteria for omnidirectional departures are applied. Omnidirectional departures may specify sectors to be avoided.
This is a quote from my theory textbooks.
gallois wrote:
NON-PRESCRIBED DEPARTURE ROUTES
At many aerodromes, a prescribed departure route is not required for ATC purposes. Nevertheless, there may be obstacles in the vicinity of some aerodromes that have to be considered in determining whether restrictions to departures are to be prescribed. In such cases, departure procedures may be restricted to a given sector(s) or may be published with a procedure design gradient in the sector containing the obstacle.
That is new to me (what is this theory textbook reference?) but it’s clear you have to do-it-yourself which is ok for a departure without ATS and without IFP (“on common sense”) but while insude Shoreham ATZ, you can’t bimble like you want, it’s ATC, once you exit ATZ, you are free to turn !
As I said, from Shoreham RWY02, if ceiling is less than 1000ft AAL, I want to turn sout-east right after DER and 500ft AAL, I am very happy to make that with 600m visibility (I can clear 50ft obstacles on my takeoff roll), will ATC approve it? I can do it without asking: they are non-radar and don’t see or say much when aircraft goes into clouds but they still manage circuit & approach on procedural clearances
