SOLENT DILEMA

[theolderflyer]

SOLENT DILEMMA

I wonder if any more experienced pilots could help me with the following.

I am planning a VFR route along the Solent to the west then to a turning point at Lyndhurst via the bulieu VFR before going south to the west of the Isle of Wight then back east, south of the island.

This wil involve operating in the vicinity of the the Solent CTA either below 2000ft or above, with clearance.

If I elect to stay below 2000ft the MSA is 1900ft at one point so there is not much room for error. It might be less hassle but more nerve racking.

If I seek clearance from Solent Radar say south of Portsmouth and don't hear from them because they are too busy do I orbit outside controlled airspace in anticipation or simply fly below 2000 and call say Bournmouth for a traffic service.

Also, if I do get clearance will they direct me via a specific route or will I be able to choose?

[robin]

In that area 1500' is OK and it would be better to speak to Bournemouth

[Whopity]

If I elect to stay below 2000ft the MSA is 1900ft

MSA has nothing to do with VFR flight!

When near controlled airspace it is far better to be talking to them and obtain a clearance where necessary. Just tell them where you are and where you are going. You are the pilot, always tell ATC what you want, if they cannot accommodate it, they will tell you. Their job is to coordinate not prohibit!

[robin]

Their job is to coordinate not prohibit!

.... but look at the MORs that Solent keep banging in......

[ChrisA87]

I'm by no means experienced but have done several Solent CTA transits and found them to be very helpful

I'd give them a call nice and early, they'll probably give you a ATSOCAS and tell you to remain outside while they coordinate your clearance. If you've still not recieved it as you approach the boundary then go underneath and climb once you've gotten clearance - if that's what you want.

I bet they'd rather you be communicating in some way (or at least squawking 0011 - Solent listening squawk http://airspacesafety.com/media/474/...quawk_2012.pdf) than pottering on your merry way without talking to anyone.

[RTN11]

Haven't flown round there for a long while, but it used to be easier to talk to Bournemouth who control a lot of the stuff up to 3000' - the map used to say see note x and all the info was in the legend.

Once talking to Bournemouth, they could negotiate any further clearance and then hand you on to solent.

Unlikely you'll get clearance above 2000' through solent though, as they'll be vectoring stuff all the time and you'll be going right through their approach. More chance if you go through the airfield overhead.

And forget your MSA stuff, if you're flying visually it has no use at all. 15-1700' is ample around there.

[BackPacker]

MSA is 1900ft

The MSA is by no means a minimum altitude to fly at, when flying VFR. You can go down to 900 ft and not hit any obstacle, since the safety buffer inherent in the MSA is 1000 ft. And you can even go down to below 900 ft and not hit anything. Although if you're not paying attention, the chances of hitting something will increase then.

It's all a matter of situational awareness and taking a good look at the map where the obstacles are that actually define the 1900ft MSA.

Here in the Netherlands, we are severely limited by the Schiphol TMA (class A), which starts at 1500'. Also, somewhere in the grid (SW of Utrecht to be exact) there is a single 1200' TV antenna, which makes the grid MSA 2200'.

If we would insist on flying above the grid MSA at all times, then about 1/5th of the Netherlands would effectively be closed to VFR traffic. Instead, we happily bimble along at 1200' or so, and as long as we stay clear of that single mast, there's nothing to hit whatsoever at that altitude.

In fact, the official advice over here is to remain about 200-300' below the base of CAS. Not just for altitude inaccuracies/errors, but also since a CAS base of 1500' means that traffic is vectored at 2000' (500' above the base), and wake turbulence is known to extend up to 700' below the flight path.

Also, if I do get clearance will they direct me via a specific route or will I be able to choose?

You typically ask for a specific route in your initial call, and more often than not your initial clearance will be along your requested route. But plans change, even in ATC, and I've had revised clearances to obscure VRPs during transits as well. And an "unfamiliar with XXX" from my side simply got me a vector.

The chances of getting cleared on the route you want, and actually being able to fly that route, increase dramatically if you know the typical operations pattern of other traffic in the airspace. If your route takes you straight through the active ILS approach, you'll be in for a lot of messing about. OTOH, if your route leaves you clear of the ILS areas, and for instance cross the overhead perpendicular to the runway at an altitude that doesn't interfere with the missed approach path, then it's much easier for a controller to let you fly your preferred route.

In any case, if you do get a transit through controlled airspace, be prepared that the actual route you get might wreck your plans, and you might exit the airspace at a location which you had not anticipated and not planned for. Without a GPS it's actually very, very easy to get lost this way.

[wb9999]

BackPacker, that's not the case in the UK. The MSA on the CAA chart is the height of the tallest obstacle, or highest land + 300 feet.

But I'm unsure how theolderflyer comes up with an MSA of 1900 feet. The CAA charts shows 1300 feet for the Isle of Wight (transmitter at 1297 feet amsl), and 1000-1200 to the east and west.

[BackPacker]

Then it's not called the MSA but Minimum Grid Altitude or something like that.

The "Minimum Safety Altitude" should include the 1000' buffer. Otherwise it would not be a "safety altitude".

[wb9999]

The correct term is MEF - Maximum Elevation Figures. Stupid mistake by me saying MSA, when I meant MEF!

I don't believe MSA is defined as being 1000 feet above the MEF. That is how some instructors teach, but others say 500 feet. Legally you could fly below the height of the obstacle, as long as you are at least 500 feet from it.

[foxmoth]

BackPacker, that's not the case in the UK. The MSA on the CAA chart is the height of the tallest obstacle, or highest land + 300 feet

I think you are mixing meters and feet here, MSA is highest obstacle or land + 300 METERS or 1000', look it up! But as a few people have said, you do not have to be above this if VFR, many PPLs are taught to put down the MSA on a nav without it being explained why - indeed I think some instructors do not even know this - this is the minimum height to climb to if you were unable to maintain VFR, if things got that bad and it means you need to climb into CAS then certainly I would say they you do it, calling a Mayday at the same time if not instrument qualified, but certainly coordinating in some way with ATC.

[wb9999]

foxmoth, no, the MEF (which I stupidly called MSA) on the charts is highest obstacle + 300 feet.

I don't believe there is a legal requirement for MSA for VFR pilots - only IFR (which is 1,000 feet above the highest obstacle within 5 miles).

From a CAA Safety Sense VFR Navigation leaflet:
Identify high ground from the spot heights and contours and remember that the highest point en-route is often the top of an obstruction. Calculate and note the minimum altitude you can safely fly each leg.

[India Four Two]

theolderflyer,

I would be interested to know how you get on with Bournemouth. My only experiences with talking to them were decidedly negative. "Stay clear of the zone" or words to that effect.

However, in their defence, the last time I tried for a zone crossing, they were amazingly busy. As I crept round the north and east of their zone, I heard them managing three aircraft!

[foxmoth]

Wb
I would be interested to see your reference - mine shows the addition for MEF is not 300' but a variable amount depending upon height of the obstacle and is in the order of 100' for a 2000' obstacle, then rounded up to the nearest 100' if not exact 100's.
I think you are getting the 300' from the fact that objects under 300' are not shown on a CAA chart, so if looking at terrain spot heights then you need to take this into account, the MEF marked does take this into account though.

You are correct that in VFR you do not need to be above MSA OR MEF, though the MSA should ideally be known in case the weather is not as forecast and you are unable to maintain VFR.

[Morris542]

I went through that same bit of airspace on Bank Holiday Monday for the first time. I went underneath CAS at 1700’ with no problems – the VRPs are easy to spot and I had a basic service from Bournemouth who were very helpful. Give it a go, great fun.

[m.Berger]

Give Bournemouth radar a call, ask for a basic service, tell'em where you are going and stay below 2000'. They'll give you a squawk and might ask you to report over Beaulieu, which is easily found. By far the easiest way, it even works for me!

[BackPacker]

mine shows the addition for MEF is not 300' but a variable amount

What I was taught is that the MEF is actually the highest of the following two:
- Altitude of the highest obstacle, rounded up to the nearest 100'.
- Altitude of the highest terrain, plus 300' to account for an unknown obstacle, rounded up to the nearest 100'. (There is no notification requirement for obstacles up to 300'; that's why we add 300' if we use the highest terrain figure.)

The MSA is then 1000' above the MEF, or 2000' above the MEF in mountainous terrain.

You can calculate these numbers in a number of ways:
- Take your route, look left/right 5 or 10 miles, and work from the highest marked obstacle or spot height
- Take the grid MSA/MEF that's written on the chart for every 1/2 degree lat/long.
- Take the maximum elevation figure that applies to the whole chart - it is usually listed somewhere up front or in the legend.

In any case, if there are MEF and/or MSA grid numbers on the map, then the legend should somehow explain how these were calculated. The Jeppesen VFR+GPS, for instance, lists this in the legend:

Minimum Grid Area Altitude

These figures are shown within grids defined by each half degree of latitude and longitude. This value provides clearance of all terrain and obstacles by 1000ft in grids where the highest point is 5000 ft MSL or lower, and by 2000 ft in grids where the highest point is 5001 ft MSL or higher.

Further down it also shows the elevation of the highest spot on the map (in ft MSL) and the location where this can be found.

[J.A.F.O.]

wb

I'd be interested to see your reference, too as - if you are correct - I had also misunderstood how MSA was calculated.

[caber0]

My various instructors have had different opinions on MSA. Certainly basing it on the Grid figures in Scotland is not very sensible. The prevailing opinion is to find highest terrain within 5 Nm of track add 300 in case of suddenly appearing wind turbines then 500 for clearance. This frequently works out very significantly higher than planned altitude particularly if you are flying a coastal route in the West or messing around anywhere near the airspace in the central belt. The opinion on when you would use it does vary. Recently qualified instructors say you should immediately make MSA if in inadvertent IMC before making a 180, older instructors agree that if you are reasonably confident of position make the 180 first and then go MSA if you do not fairly promptly return to VMC. Certainly that is what I would be doing as there is a higher likely hood of being stuck in IMC if you go higher.

Caber

[foxmoth]

Caber, if you DO go IMC then, the MSA is 1,000 feet - you are flying under Instrument flight rules and the rules state:-

33 (1)
Subject to paragraphs (2) and (3), an aircraft shall not fly at a height of less than 1,000 feet above the highest obstacle within a distance of 5 nautical miles of the aircraft unless:

As to climbing.before or after the turn I think that is a matter of airmanship and how aware you are of where the obstacles are, certainly climbing then turning can mean you will almost certainly NOT come back out after the turn, but then neither do you want to hit something during the turn. Ideally of course you will have turned round well before you get into this situation!