@RobertL18C to be a bit picky, I know, I think category A is maximum 91kts Vat not Vapp.
@gallois agree 1.3 times stall speed in landing configuration, so Vat.
RobertL18C wrote:
Whether to attempt the landing on the go around the aircraft was still below Cat A Vapp is not easy to conclude.
I’m a fan of Occam’s razor and on balance I don’t buy the story about attempting to land after starting a go-around.
Simplest explanation is just continuing way below minima using a GPS overlay and then becoming visual very late in a less-than-optimal position to touch down at the start of the runway – which you’d need to do landing that aircraft on a 600m runway with a 10kt tailwind. Report suggests they missed most of the upslope at the start of the runway leaving ~400m to land on, and the AIP entry says that the last 100m is a 1:32 downhill gradient.
The Aztec POH suggests that for those conditions you need ~720m (including the x1.33 CAA-recommended safety factor), assuming 50ft at the threshold and probably touching down somewhat earlier than was managed.
Thinking about the apparent non-requirement to be on a published approach if descending below MSA in IMC for the purposes of landing, this may create an issue with minima on published approaches. On passing minima a pilot could just declare themselves no longer on the published approach and utilise the non-requirement to be on a published approach in order to descend further. Thus minima mean nothing?
Graham wrote:
Thinking about the apparent non-requirement to be on a published approach if descending below MSA in IMC for the purposes of landing, this may create an issue with minima on published approaches. On passing minima a pilot could just declare themselves no longer on the published approach and utilise the non-requirement to be on a published approach in order to descend further. Thus minima mean nothing?
Interesting point. But that scenario would be possible on a published approach to an uncontrolled airfield, correct? Are there any uncontrolled airfields with published approach procedures?
Hello folks,
Thanks to @Airborne_Again comments, I’ve done my own cloudbreak procedure onto Turweston EGBT, following the procedure laid out in
http://www.aglarond.se/airborneweb/documents/Unpublished%20approaches%20v2.pdf
The procedure consists in leaving the IAF DTY on R126 to 12.0 DME. Then turn right to intercept the 268 QDM to EGBT. The FAF is at 6.6 NM from EGBT ARP.
Platform altitude 2500 ft on the QNH.
I’ve decided on a DA of 1040’ (600 ft height), which happens to be exactly 2.0 NM from the ARP.
Visibility required 3600 metres, recommended 4500 metres.
Missed Approach: continuous climb to 3000’, initially climb straight ahead to ARP. Then turn right onto track 290. At 2500’ turn right to DTY VOR.
So I flew this on XP11 with a rather fast DA62 to see how it played out and the results are pretty good. A bit of an overshoot on the turn to intercept the EGBT QDM but otherwise worked out pretty well. I’m looking forward to trying this out in real life, in VMC first. Then possibly wearing a hood with a safety pilot.
Does it make any difference flown on DA62 vs C172? I guess both are CatA?
Ibra wrote:
Does it make any difference flown on DA62 vs C172? I guess both are CatA?
I think you are right but when I did my IR in the DA42 we treated it as a Cat B. I believe people default to treating MEPs as B?
With the DA42 we flew based on power settings (load) rather than airspeeds. So I would set 50% load before reaching the IF, that would result in 110 KIAS I believe. At 0.3 NM before the FAF I would extend the landing gear and one stage of flaps, without touching the power, on the glide this config and load would result in 90-95 KIAS. Minimums, runway made, full flaps and we’d cross the threshold at 85 and touch down at 75-80. So this complies with Cat A but we used Cat B minima anyway.
Cat A & B have the same MOC for obstacles but they differ in visibility & circle minimas (even with same AoB or DH)
But maybe none of this matters with 600ft agl & 4.5km vis as Cat A & B & C can fly while Cat D can’t 
Is it necessary to go out to 12D from DTY?
If you turned a bit earlier you could make those angles a little less sharp and reduce the overshoot. The problem with your short leg after the first turn at 12D DTY is that it’s too short (with such tight angles) that one can’t re-establish following the overshoot.
I’d put a waypoint on the DTY 126 radial directly due north of your FAF. Then make these two waypoints (that one and the FAF) fly-by rather than fly-over.
Of course using DTY as an IAF is not really necessary, since this is a home-brewed GPS approach, but perhaps desired for the exercise you’re conducting? For practical use I can’t see any particular reason not to have an ordinary T-shaped approach with north and south arrival options as well as straight in from the east and no involvement of DTY…
