Who won't fly an IAP which will kill them if they screw up totally above decision height?

You guys want to try calibrating these places where the requirement is to fly the ‘edges’. Ones that spring to mind:

Aqaba ILS RW19. Anything more than 7 deg left of centreline and you’ll likely hit a mountain. We fly a left slice at 1000ft above threshold and are at 20ft radalt for about 3nm.

Al Ain, ILS RW01 – similar issue with high ground when testing ILS loc clearance signal (+/-35 deg of centreline)

Hawarden ILS RW04 – high ground.

Glasgow ILS RW23 – high ground at 12nm final. Flight profile requires 1000ft at 12nm which is impossible. As with Aqaba, we end-up at 15-20ft radalt crossing a ridge before making a dirty dive to 1000ft by 11.4nm.

Derry ILS RW26 – high ground and wind farm. One profile flies between two wind turbines.

The list is long. My observation is that anything more than half scale deflection, or equivalent, can get sporty. JasonC has it right – fly it accurately, at all times.

There is one statement from a very experienced pilot which wasn’t related to IFR flying, but rather mountain flying, could be applied here in my opinion. The statement is: “I will only accept one difficulty at a time”.

So if everything is perfect, i.e. you know the particular aircraft and avionics by heart, are very IFR current, maybe have a second pilot in the right hand seat, no icing to be expected – then I would accept flying a challenging approach. If I feel that one of these factors is not as it could be, then I would probably not fly it. For example Svolvaer comes to mind, we had planned to stop over but when we saw the low cloud base, which may have turned out to be above or below the relatively high minima, we decided to do the stop another day. Not yet having flown many approaches with that particular plane was one factor. Was much nicer to visit in good weather as well.

From the Annecy IFR Airport Briefing :

Localisation
The airport is situated to the West of the town of Annecy approximately 18 Nm South of Geneva. It is
surrounded on all sides by high terrain. There is high terrain immediately to the North and West of the
airport. On approach to RWY04 the NDB “AT” is situated on top of a hill 2,454ft MSL, 5nm SW, giving
ground clearance of only 1,000ft when at 5 NM from the threshold 04. There is a hill 5,624ft MSL, 10nm
South. Minimum Safe Altitudes (MSA’s) are based on the Chambery CBY VOR, located approximately
15nm WSW of the airport. Additional hills exist at 9,700ft MSL to the SE, 7,200ft to the NE, and 6,500ft
to the West. Refer to the Jeppesen Radar Minimum Altitudes chart (10-1R) (see below).

I was the one saying that I would fly this approach only in VMC. I’m sure I can fly the approach accurately, but single pilot in a non-deiced SEP with just a single G530 nav box and an unreliable AP I just don’t fancy flying the approach down to minima.
It might be different if you have a more capable platform with FIKI, excessive climb power and a certified device showing terrain…

Peter, we tend to look at full scale deflection. However, many of those listed above do not allow full scale and some are perilously close to half scale; ordinarily you’ll find a bit in the AIP entry/on the plate explaining the limitation. Pilots will ordinarily see the limitation as a step fix if the issue is related to the centreline. In the case of Aqaba, you’re instructed not to use the localiser outside of 10deg – there’s no radar so you’re relying on an in-line VOR and NDB.

Others, such as Glasgow are a bit more academic as in that scenario we’re trying to ascertain signal strength at 0.3*Theta, Theta being the notional GP angle. You would have to have done something really stupid to be that low on the GP at that range.

My plane is based in Annecy. Yes there’s a lot of terrain but I have flown the approach to minimums many many times during the winter and there are no issues. They will turn on the running rabbit as well if you request it.

Some valid points though, in winter if your plane is not TKS or FIKI or de-iced in any other way then I would not be flying there as the missed will most definitely put you back in the soup and you may ice up. Also there is only one approach into 04 and the circle to land or VPT is not something I would recommend doing even in fair weather. There is terrain on that side of the airport. You’re much better off landing with a tailwind depending on personal and aircraft limits. Personally up to 10kts on the tail I will always land straight in 04.

I am slightly surprised there is some discussion about whether or not you should / could / would fly a particular IAP and whether or not in theory you should be capable fo doing so.

Much as in the commercial word and certain runways being captain’s only, I think every approach should be considered both on its merits, the pilots merits and the aircraft’s merits – in other words one hat does not fit all.

Obvioulsy the “wrong” aircraft and “wrong” equipment will eliminate certain approaches without further consideration. Then surely it must depend on pilot’s currency. Why would one fly a more difficult approach if not current? Of course and as ever judging what you might or might not be capable of doing is the hard part and being prepared to push the boundaries a little but not too far.

jwoolard wrote:

the go-around is an exercise in interesting NDB tracking up a narrow valley flying straight at a small mountain

That used to be true for a number of commercially served airports in Norway. I have been told by old pilots that they were actually flown with the NDB being the only source of radio navigation. Many had/has LLZ guidance (glideslope does not work in steep valleys/mountains), but only for approach. Of course those airport all (all?) have RNAV approaches by now.