RobertL18C wrote:
BTW a diy OBS 3 degree slope will not provide obstacle clearance in quite a few airports in the UK, I wonder if Garmin software integrates topo database to alert flight crew if this is the case.
Garmin do check for terrain before showing 3deg glide path and it does uses airport data and some obstacles (but not all obstacles) but yes most non-IFR GA runways need steep glide slope than GTN hard-coded 3deg to clear obstacles or are hard to land on in VMC 
However, AFAIK, there is no database for obstacles less than 300ft agl published anywhere? one just need to pay for surveyors to do the job or do his personal visit, one has to be really mad flying DIY without regular “VMC picture” visits carrying excess of steep speed & height…
Even if GPS database is 100% accurate, flat terrain and no obstacles barely mean 5km visbility & 700ft agl (50ft + 300ft +295ft + 50ft)
If it’s not DIY on Garmins, it will be DIY on SkyDemon, DIY on VOR radials, DIY cross-country VFR in IMC at obstacles levels
IMO the biggest limitation is not obstacles or ceilings, altough these seem more dramatic
It’s overshoot risk on a typical 600m short GA runways comming fast & high in low visibility
RobertL18C wrote:
the contributor referred to in Airborne_Again’s article
If we think about the same accident then it was not a DYI approach and no regulations were violated.
Airborne_Again wrote:
If we think about the same accident then it was not a DYI approach and no regulations were violated.
Were you on board?
Graham wrote:
Were you on board?
That was uncalled for. I read the accident report.
Airborne_Again wrote:
No. but I read the accident report.
As did I. I just wondered (genuinely) if you had cause to know more than was available from that.
On a UK GA site, someone famously said “I stopped taking it seriously at the sixth word because I knew that was bolleaux and it was BS after that.”
To save you opening it, the sixth word is “NDB”.
So the conclusion under Part-NCO: it’s legal to fly bellow 1000ft agl IFR MSA for landing, the same way it’s legal to fly cross-country VFR few inches bellow 600ft agl ceilings and the choice is left to the PIC to decide
Did anyone produce a technical document or guide on how to fly the (legal) “VFR scud running” yet?
However, he did not carry out a landing performance calculation to check if there was sufficient landing distance available on Runway 32 with the tailwind.
This NDB only approach is restricted to Category A, Vapp below 91 KIAS. Whether to attempt the landing on the go around the aircraft was still below Cat A Vapp is not easy to conclude. A request to carry out, presumably a DIY approach to 14, was not allowed due to no published approach on this runway. The tailwind on 32 was on the TAF. Metars had ceiling at or below minima, although technically an approach ban did not apply. TAF had visibility below system minima.
Performance and M&B calculations are a legal requirement and are on the ramp check lists by inspectors.
Performing a ground loop to avoid going off the cliff did allow everyone to emerge unscathed.
@arj1 Yes but it’s textual data not coded in GPS databases, maybe SkyDemon who have the tradition of spoofing AIP & Notams entry data could get us something? but what they have now as terrain & obstacles just filters out anything bellow 300ft agl
Also, I doubt one can rely on AIP AD entries for an IAP obstacle surveys? otherwise where does the money goes?
Obviously, no one is going down to 100ft agl obstacles on DIY and anything bellow 300ft agl is just highly theoretical, one rarely get the chance to do that even on ILS and 3km runway (except in Biggin Hill when it’s 300ft agl whereas it’s 1000ft agl VMC everywhere or everything in U.K. SE is under the fog except Biggin Hill), so the debate is mostly about 500ft-1000ft agl bands…
Anyway obstacles is the least of the worries if ones alternative plan is to fly low VFR, the other limits to DIY IFR approach is lack of reliable data on wind, visibility & ceiling & QNH when one is inside the soup (and maybe no point asking some random radio guy for that data, some are not qualified to provide it or will not reply) but one can always do dry run cloud-break somewhere familiar: ILS instrument runway nearby or specific points in open water or free terrain first (are these “Low Pass” legal if the intention is not to land?) get measurement & comfort before heading to destination either IFR above MSA or VFR bellow MSA 
RobertL18C wrote:
Performing a ground loop to avoid going off the cliff did allow everyone to emerge unscathed.
No I’m totally confused. Are we talking about the Scillies accident or something else?
