Like many other tools WAAS/EGNOS used for LPV approach is useful when you need it.
Yesterday I flew to Annecy LFLP and made a landing that would be impossible without LPV. The initial forecast, checked few days ago, was CAVOK then it worsened a bit but then another bit. Yesterday morning TAF gave BKN022 and FEW015 which was still OK. However, during the flight new TAF gave TEMPO BKN009 which was still kind of OK but not ideal for the airport with DH 730 for LPV or MDH 1150 for LNAV. A bit lower minima can be used with better climb gradient for go around and mine is 600 feet with 3% gradient (DA 2080 feet). Latest weather given by tower before the approach was BKN009 and visibility 4000 m. When dived from 5000 feet to what looked like a solid overcast, I popped out from it exactly at 2200 feet (710 AGL) and before that I wasn’t able to see even a glimpse of ground, just solid thick cloud.
Isn’t 710 AGL below the DH of 730?
My humble guess is that Emir was flying in accordance with a DA, became visual at 2200 for a corrected Cat A minima of 2080, e.g. 120 above the minima, so all good 
Yes, LPVs is great stuff, the more so for exotic destinations where the implementation of precision approaches has not been possible. Pity the UK lags so far behind…
Isn’t 710 AGL below the DH of 730?
There’s a table of different DA based on climb gradient and 730 applies to 2.5%. I used 3% (as @Dan correctly assumed) because that was my OEI climb gradient for yesterday’s landing mass. Actually it’s closer to 3.5% but I like to be more conservative in such weather.
I would have expected this thread to be 100 posts by now, with so many posting about how LPV saved the day. But we get only a few. Maybe it reflects GA reality (really bad wx tends to be avoided) and airline reality (no use for it at all).
On multi-engine airplanes, and preferably types allowed for flying into known or forecasted icing conditions (but not limited to!), I see some, but few, advantages of having LPV approach capabilities on day to day basis, from a private pilot operational perspective, unless some very specific personal requirements exists (business, get home, etc.). Upgrading to this type of equipment for the benefit of LPV, at the prices tag it comes at, seems a bit over the edge to me (subjectively).
Comparing the (3D) LPV minima to the (2D) LNAV minima is not really the comparison I would make. If the airport has an LPV approach, it will surely also have an (3D) LNAV/VNAV approach (non LPV capable GPS), since the vertical path area has already been guaranteed (for the LPV approach). The airport LFLP has LNAV/VNAV minima (Cat A) of 920ft, LPV CAT 1 minima (Cat A) of 730ft and LNAV minima (Cat A) of 1151ft. It´s worth noting that the visibility/RVR requirement are the SAME for all 3 approaches (including the (2D) LNAV only|) of 1500M.
But, you´re very right, on the day you executed the approach and became visual at 710ft, you wouldn´t have made it on any of the other approaches.
If you would have carried 1 hour extra fuel, you´d theoretically have been fine, waiting out the tempo in the holding.
On a side note, and easily forgotten (surely you didn´t), there´s likely a cold weather temperature correction to the minima, with winter temps around 0C. With a DH of 730 feet and a temp of +2C, that would amount to approx. 30ft additive, so the temperature corrected minima would be 730ft (published minima) + 30ft = 760ft DH or 2249ft DA (temperature corrected minima). For the missed approach gradient you wisely used, I see the LPV minima at 600ft DH, so yeah 630ft corrected DH (2119ft DA).
Just an observation.
What does LPV approach do for you on an single engine piston (SEP) airplane? I suppose you´re capable of planning and executing IFR LPV approaches, but in reality are you going to plan AND fly to low (IMC) LPV minima on an SEP? There´s so many foreseen and unforeseen threats in low level IMC flying on an SEP. Of course it´s nice to be able to legally fly an LPV approach the day the sh@t hits the fan – but that´s certainly risk management and risky business. I would think that a “basic” GPS allowing for a 3D approach (or even simply 2D LNAV) with LNAV/VNAV minima’s would be sufficient, in addition to ILS capabilities.
3D LPV approach capabilities are for multi-engine airplanes, unless of course your risk behavior tolerates the threats of SEP low level IMC flying. It´s a personal choice.
Peter wrote:
But we get only a few. Maybe it reflects GA reality (really bad wx tends to be avoided) and airline reality (no use for it at all).
some reading https://en.wikipedia.org/wiki/Enhanced_flight_vision_system
@Peter
In GA world it‘s too expensive to go to places with bad weather. You stay better at home. In the airline world you have to push the limits and I find it a good safety culture of the GA pilots not to push the limits because of lack of experience mostly. And not to push the limit in an area of LFLP when you are not 100% familiar with your avionics and aircraft is very wise.
To me the only loss of LPV is for IR skills tests and training.
The minima offered by an NDB approach gives a minima that I have never had to or ever likely exceed in a lowly PA28-140 so the loss of LPV has made no difference.
Of course in the UK the lack of available instrument approaches, regardless of the type, is the biggest problems and this is just getting worse.
No question about LPV value.
Recently we designed one helipad with LPV200 in mind.
Some of locals put the big question mark on that…
Later two visual test / verification flights in Dec 2023. was canceled
because of METAR :P
