Shoreham EGKA to Mali Losinj LDLO and back, August 2018

I can load the GPS track into Oziexplorer and view it in any map of my choice. But I still can’t find those mountain lakes.

The EXIF on the photo is 26/08/2018 10:42:37 and the corresponding entry in the GPS track is 47.451053, 7.702828 but that doesn’t show anything. So I uploaded the track log here; it ought to be easy to convert it.

I also exported it to KML and found the lakes on Google Earth:

46°11’16.26" N 10°28’20.94" E

Found them:

I use the Autorouter Gramets routinely and don’t think I’ve used Ogimets for years. Are the data sources entirely different, explaining why the latter gave you wx for the destination and the former not? As a matter of interest has anybody done any kind of comparison between the two for accuracy checks?

AFAIK: both come from the US GFS model. Historically there have been two projects which took that and did extra work on it to hopefully improve accuracy: Meteoblue (a PhD project of some student; later an attempt was made to commercialise it), and OGIMET. I wrote about this here. I don’t think the AR Gramet does any additional processing, beyond drawing the various cloud shapes according to convective energy etc, and I have never found it showed anything which wasn’t obvious from the MSLP chart. Also bare GFS often fails to show low level cloud (at a few k feet) completely. Nowadays I find windy.com to be much better especially as it runs the ECMWF model.

At FL170 it looks at a quick glance like you’ve got about 6 degrees nose up to maintain level flight (but for a nice GS of 142 its for 8 g/h).

The IAS looks crap (95?) but the TAS is normally about 140kt, at c. 8.5 USG/hr.

I’ve just bought the O2D2 system and will certainly use it for the Alps crossing on my trip in my C182 (230 hp). Any tips on flying that high (apart from the obvious ones about hypoxia/icing etc)?

No; it just works… it is automatic. I do have two of the O2D2 regulators to (a) provide redundancy if flying 2-up or (b) serve 4 people.

what kind of climb rates do you get at that sort of level?

Roughly, the TB20 does 1000fpm at SFC, reducing linearly to 0 at 20000ft. So at FL170 you are doing something slightly better than bugger-all The real issue is the temperature. In ISA conditions the TB20, especially light, will go to FL210 and on one flight test I did (ISA minus something) it was clearly going to climb to FL230 but London Control refused (it was a flight test above Norwich). The problem is that in the summer it is always well above ISA and that knocks the performance. We have some previous threads on the extent of the effect.

What about shock cooling in the descent – which many think is an exaggerated issue?

It doesn’t exist unless

• CHT is above about 400F, and
• you close the throttle rapidly, and
• there is a decent speed (cooling airflow)

Flights at/above FL080 or so are done with a wide open throttle completely, and descents are not done so steeply because it is not fuel efficient to fly too fast.

I don’t have all that many suitable tracks, and the spaghetti western (and Winnetou) music is really appropriate for the Adriatic scenery

In the interests of accuracy I have replaced the video file with one showing the correct names for those lakes