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Your VFR limits

I know there are a lot of IFR residents on the forum, but I thought I would pose a VFR based question to drag you all down to my level

The question is: What are your VFR limits?

Typically these are articulated in terms of vis, cloudbase, wind...but feel free to expand on these as you wish.

Yes, I know this is a very non-specific question. I know it might "depend" - we'll take it as read that most pilots aren't entirely prescriptive robots, but sometimes base decisions on a whole range of factors. The aim is not to get chapter and verse on what you might do in all conceivable situations, but to attempt to define a distribution / paint a general picture of what typically EuroGA residents are comfortable flying.

You can try and define "typical" in a more prescribed way (like a weighted average approach). Or you may wish to recall any memorable go/no-go (or keep going/turn around) decisions you made, relevant factors in the specific decision process and whether or not the correct decision was made.

For me it's really just a matter of curiosity, and an opportunity to give everyone the chance to see how their contemporaries operate.

I fairly often take off and land at non ATC airports, or airports without a published approach, or one where I have not booked a slot so cant assume I can just request an ILS approach 10 NM out. I also fly a SEP and have an IMCr.

On that basis my minimas are generally this:

  • Cloud below 1000 ft AGL.
  • Viz 3k.
  • If rain is forecast, I prefer it is scattered or isolated showers and not widespread big bands of rain.
  • Any PROB30 bad weather is thoroughly checked against other sources for my own view on the probability.
  • I have a route where I can potentially try to out climb any cloud.
  • Cloud is not likely to contain any embedded CB's.
  • Icing will not be an issue.
  • If I get delayed anywhere due to weather I wont be causing upset to myself or other family members (i.e. other social commitments).

Obviously some of these things are changeable, and the route and quality / convenience of alternatives or availability of radar services en-route is a factor.

Yes, that depends strongly on what the route and task is. With my very limited experience of around 500 hrs, I set very high limits in order not to even get into a situation where I am tempted to bend my rules.

Generally, for "normal" flights within my shorter range and in places I know and have flown many times to and from, my limits are lower than if I go on longer trips. I would consider and have done to do a short hop to maintenance or to an airfield in my immediate vicinity to GAFOR Standards "difficult" which means 5 km vis and 1500 ft ceiling RELIABLY verified on the whole route.

For longer trips, I will not accept any route which forecasts clouds more than FEW lower than 2000 ft above my highest planned altitude and visibility of less than 10 km anywhere on that route. For trips outside the Alps, that would require a verified cloud base of around 7000 ft AMSL for the whole route.

In the mountains, basically I want CAVOK. I want visibility >10 km and a ceiling, if any, which is at least 2000 ft above the highest peaks on my route. Obviously NO convection at all. Normally,that means 15'000 ft AMSL. I would accept a crossing below a high AC cover or I would also accept to be on top of a FEW to SCT situation with the maximum cloud top of 2000 ft below my planned altitude. The alps are the biggest challenge over here. Chance is that either north or south of the alps are flyable, very rarely both sides. Add to that the horrible airspace structure south of the alps which restrict the choice of route massively. Consequently, the Alps are closed for crossing VFR 80 to 90 % of the time.

For longer trips I set myself a deadline a week ahead of departure. If there is any indication at all that the trip can't be done in basically CAVOK conditions, it is cancelled and I go on the airlines. If it is still go at that time, I do a re-assessment of the situation every day before the trip also for the return flight the long range model data become available (which is about 10 days ahead of time). Again, if there is any doubt that the return flight can be done within 2-3 days before the planned return, the whole ops is off.

In the last 2 years this policy has lead to cancellation of all trips but one which was decided on short notice and to cancellation of all but 2 alpine crossings. The reason for this is that I am workwise totally inflexible with my flying dates and therefore need to plan ahead weeks and months ahead of time. I have to be able to plan a fixed departure date +1 or 2 days and a fixed return date -2 or 1 day. That means 2 windows of 3 days each at a schedule fixed up to a year in advance.

I usually do an analysis of the actual conditions in the aftermath of any flight or cancellation. This has shown that so far, all of the cancelled flights would have ended somewhere en route with a no go situation, so cancellation was fully justified.

VFR, I have found, is not suitable for this kind of travelling at all with a cancellation rate of 90% on average.

LSZH(work) LSZF (GA base), Switzerland

I suppose it would have been more polite to define my limits as well as posing the original question.

I have 25 hours P1, so my experience so far hasn't lended itself to huge amounts of experimentation. I'm aware of many factors I could take into consideration in my go/no-go decisions, but I don't. For now I deliberately keep things simple, using my training limitations as a principle baseline:

  • Greater than 7k vis
  • No cloud SCT or greater, below 2500 feet
  • 20kt absolute wind, 10kt x-wind

This is fixed for nav's, where I will expect to see no consistent forecast's that suggest these limits will be busted. If I see ISOL or prob 30's, I'll be prepared to depart with a thorough self brief to keep an eye on the limits and turn around is things start to deteriorate. Under supervision, I'd like to do some local flights in slightly worse cloud conditions (say SCT013), to assess how I cope.

I've already been caught out once. Departed on a nav with 15kts straight along runway...arrived back to home base to find wind had increased (completely unforecast) to 31kts, 30 degrees off of runway. That was a fairly hairy end to the flight - an unwanted albeit great learning experience. I got down perfectly safely (at 2nd attempt!), but would never have departed in it.

Visibility:

Firstly much would depend on whether I am using a GPS, or navigating conventionally.

With GPS, I am happy to go down to the legal min of 1500m, which is actually very thick haze and you won't see the runway until on a 1 mile final (1500m is about 1nm).

Without GPS, I would want 10km+. With 5000m, one cannot see very far ahead and visual nav at say 2000-3000ft is very hard. You really cannot afford to make any mistakes in feature identification - unless of course you know the area but that is cheating

In anything below about 5000m there is unlikely to be a horizon so you are looking at instrument flight conditions, especially over the sea.

I have been flying 100% on GPS (with VOR/DME backup) since the day after getting my PPL so visibility has never been an issue.

Cloudbase:

I'd want to see cloudbase 500ft above the MSA along the route, both actual and forecast. Most VFR flight has to be done below the cloudbase because you don't want to get trapped above an overcast.

As a pilot able to do instrument flight, I would be happy to fly above an overcast to an airport which is reasonably accessible from a coast, because one can descend below the cloud while over the sea. That is also a common (and safe) tactic for, ahem, using the IMC Rating when abroad, when you cannot overtly ask for an instrument approach...

Also I wouldn't like to fly below CBs, but PROB30 TEMPO is OK because they should be well spaced out.

Surface wind:

Depends on the plane and the runway(s)

Administrator
Shoreham EGKA, United Kingdom

I Take off and have a look. Most the time the Waether ist inflight much better than at the ground and forcast! To come back 900 FT AGL and 5km are enough!

EDAZ

I'd want to see cloudbase 500ft above the MSA along the route, both actual and forecast. Most VFR flight has to be done below the cloudbase because you don't want to get trapped above an overcast.

Clearly a boy from the flatlands speaking Most of my VFR flying in Southern Germany, Switzerland and Austria is way below the MSA.

For me the minimum is cloudbase 700ft AGL but only because I have an IR. This means I am safe should I enter clouds accidentally. 1500m visibility is very little, I want at least 3000m.

For me the minimum is cloudbase 700ft AGL but only because I have an IR

Yes but that is completely different, and I was trying to avoid bringing that option into it.

If you can go IFR, and it is possible to either fly in the widespread UK Class G in solid IMC, or you can get a popup IFR clearance to some high altitude (as you can in much of Europe), and you can land at an IFR airport which is, or is not too far from where you want to get to, then you can be far more reckless with your VFR minima.

For long trips, being able to navigate and fly on instruments transforms VFR flight, because one can fly VMC on top. Flying out of the UK and to the south, it is fairly easy to rig the flight so one leaves bad UK weather and lands in good weather somewhere in the south. I crossed the Alps a number of times VFR but would have never tried any of that if I didn't have the IFR option available in an emergency.

There is no way to say "I am VFR only" if you actually have an IR because the "IFR card" will always colour your attitude to the various risks. I've been IFR capable since 1 year after the PPL and I can't say I would have done any of my long VFR trips otherwise. This doesn't necessarily imply illegal VFR, or illegal VFR outside the UK if one has just the UK IMC Rating, but any extra capability (legal or illegal) will shift the risk assessment.

Without GPS, I would have never gone anywhere. Too much hard work

There has been a number of deaths of IR holders who flew into the ground when flying VFR, so the VFR/IFR transition does need some careful thought. Just climbing UP may not be good enough, if you are heading for a tall rock. A typical piston plane can make only about a 10% climb gradient (engine management to consider too). Also you need to wait for the IFR clearance, which can take minutes, or for ever.

Administrator
Shoreham EGKA, United Kingdom

For local trips in the area (1 hour) I used to be happy with 5km vis and 1500ft cloudbase, the obstacles in our area are a few high radio/tv masts and turning torso :)

For longer trips, mostly south, then a cloud base of 3000ft and 10km visibility was my safe minimums. If I chose a route directly towards Rugen I would require a higher cloud base over the water (30 min crossing). Always with GPS (G1000 and/or sky demon or similar depending on acft).

If I flew with a fellow pilot in the right seat I would lower the minimums a bit, depending on the area. Especially if the person was instrument rated.

But now that I got my IR rating I am happy with lower minimums, haven't flown any VFR trips since (except some local flights) :)

For clouds, it's around 1000feet agl as long as I am not flying in an area where I have an obstacle at more than 800ft otherwise it'll be 300 feet higher than the highest obstacle on route.

Visibility, I'd say around 4-5km visibility although temporary lower due to haze, inversion and the like are ok, but a no no in the circuit I want to see everyone around me easily.

Winds - as long as they're down the runway, I'll take anything as long as it's not gusting more than 10knots higher (eg, 20G30, 15G25 are ok, 20G35 not...), crosswind it would depend on the runway to land on. For instance, I've landed on a 10m wide runway with 13kts coming straight across the runway and that was pretty hairy, I won't be doing that again in a hurry, it's nice to know I could do it ;-)

EDL*, Germany
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