Peter wrote:
Carrying a proper topo map presentation would help, but only a little, and only if you are high enough to start with (say FL160-180), and almost nobody has such a device anyway.
What will help is a proper synthetic vision implementation on your PFD or similar device.
Most EFIS like Garmin, Aspen and some flight planners like Foreflight have synthetic vision. While far from perfect, it should give you a good hint where the obstacles are and certainly show the way into valleys.
What will help less but is still a lot better is a terrain awareness GPS. My trusty Garmin 695 and all newer GPS navigators have terrain pages which give a pretty good representation of the terrain below.
While this does not solve the final problem of finding a place to set down to land, it certainly should help to avoid the granite walls, both in IMC or night conditions.
At night, valleys can often be seen as a string of lights, particularly if there are roads and inhabited places. This should also give indications of the terrain.
I recall so far 2 cases where SEP’s had to make emergency landings at night, one on approach to ZRH which is anything but flat, I can’t remember the other one. In any case, the one in ZRH resulted in the loss of the airplane but both on board survived shaken and stirred but more or less ok.
Whatever tools you have, you can’t practice much on forced landings for real in mountain areas (unless doing it in FSX), so your first attempt will be the real one, during the day or during the night
This is unlike playing forced landings game in flat lands with your best friend looking outside while you are looking 100% inside to your moving map or synthetic vision, funnily enough jusding by the view at 500ft agl the “walk away score” of night/instrument forced landing is not far off from the one using visual external references, one out of 4 or 6 just don’t look pretty, no matter how hard you try, not sure what the score in the valleys during the day? I never tried as it’s one way outgoing only, 1 out of 2?
I am less convinced that a day crash landing will be very different than a night crash landing on 45deg terrain, aside from that you will see it coming and there is not much you can do about it…
Maybe one should try crossing the Alps in a powerful twin first? who knows how things looks like, maybe the peaks & valleys are well lit with runways everywhere (joking of course 
)
High risk => try to expose yourself as rarely as possible.
Lower risk => a little more time at these threat levels are acceptable
It´s all a game of statistics, balls and fate, I guess. I try not to fly a Rotax Aquila at night for more than I have to (being FI for night ratings). Staying in the pattern I usually climb a bit higher than normal, and I never take off to the east, as you don´t have good options to land even during daytime.
Flying cross country at night over central Germany in the Cirrus I feel fine, but I would not do it over the mountains if not absolutely necessary (99% of the time it´s not).
In the US where night flying is easy and convenient to make full use of a day, I usually rent 172s, and unless I do some pattern work on a familiar field with flat terrain I try to fly over interstates or the coastline. It´s hardly risk-free, but I feel ok with it. If I´d do it all the time I´d think about getting an NVG and some training with it.
There was a document summary that was used, ahem paid, by European manufacturers (PC12 & TBM) to push for EASA approvals for SET commercial operations, most of the hard data used to push for the case for Night & IMC was coming from US DoT & CDC on operations in Alaska which includes (overweight) single engine operation, historical data of crash fatality rates were: Night 23%, Day 15%, VMC 11%, IMC 45% (where a large proportion being CFIT)
The rest of details in documented were mostly sloppy assumptions of how aircraft flies at day, night and in weather as the goal was to come up with a single number, but at least give all the moving pieces in the problem (not surprising the number was lower than than the risk profile of less than 5700kg MEP, these are still death traps as far as FPFH fatality rates per flying hour is concerned)
report Single_Engine_Operations_in_IMC_and_at_Night_Risk_Assessment_Issue_2_pdf
Ibra wrote:
Whatever tools you have, you can’t practice much on forced landings for real in mountain areas (unless doing it in FSX), so your first attempt will be the real one, during the day or during the night
The terrain model in FSX is not anywhere close to being accurate enough (unless you use stuff like FSGX ultimate terrain) and neither are the night representation of the landscape. I hear in that regard FS2020 is totally spectacular though. And actually, playing around with such scenarios on a good FS can do one heck of good for your situational awareness, provided the aircraft and scenery is good enough. It sure helped me to stay current during my 9 year hiatus prior to 2009. I wish I had the time to do some stuff now and I certainly will once I get back to flying (well, at the moment it is my airplane which needs to get back to flying first).
Ibra wrote:
I am less convinced that a day crash landing will be very different than a night crash landing on 45deg terrain, aside from that you will see it coming and there is not much you can do about it…
The whole idea would be that you should not be in a situation where a 45 degree slope is the place you end up. Which means flying as high as you can and to be situationally aware at each moment of the flight where to turn in case of cases. I guess there are some positions from where a valley is not reachable but there are not that many, if you fly high enough.
Ibra wrote:
Maybe one should try crossing the Alps in a powerful twin first?
Powerful being the operative word. I’d take a Seneca II or other turbo twin for that kind of thing, otherwise it is the same as in a SEP, it just takes longer to descend.
Ibra wrote:
There was a document summary that was used, ahem paid, by European manufacturers (PC12 & TBM) to push for EASA approvals for SET commercial operations
The huge difference is that both of these can cross the alps at altitudes from which they almost always have enough gliding range to get into flat terrain or at the very least into a flat valley. If you have a turbine fail at FL300 it is a huge difference to a SEP which fails at 2000 ft AGL, even if that is 14000 ft.
If I can find the time I will experiment a bit in the Swiss Alps. My trusty FSX does have sufficiently accurate scenery for the purpose. I’ll post screenshots once I get to it.
I think one good thing about simulator is that you can test against proper aircraft GPS database or tablet SkyDemon then flip the switch day/night vs IMC/VMC as you reach 500ft agl, you won’t even have that luxury in real life anyway one has “to fly those valleys” on GoogleMap or FSX even for daylight flying, unless he is born over there…
SET have more power & altitude reserve foe en-route but I doubt they always fly within gliding ranges, at least not when flying in/out of Switzerland airports on +5% SID or -5% ILS with -10% L/D ratio (from 1:10-1:15) unless they climb in thermals or spiral overhead for landing
Ibra wrote:
I doubt they always fly within gliding ranges, at least not when flying in/out of Switzerland airports on +5% SID or -5% ILS with -10% L/D ratio (from 1:10-1:15)
Yes, clearly during departure and arrival segments they are as vulnerable as anyone else. But for crossing the Alps, it is a different ballgame.
Mind, I don’t advocate for any SEP or even T to do this at night or in IMC, for me that is Twin territory preferrably. In my mind I stll am dreaming of a Seneca II/III or maybe a turbo Twin Comanche, alas, I am well aware that this will remain a dream safe for a Euromillion win.
Oh what a strange debate for a GA forum.
Statistics show that a leisure flight on a Saturday afternoon is far more dangerous than sitting on your sofa having a Saturday afternoon nap.In the short term. (I do stress in the short term because the sofa sitter very often turns to obese, in the long term).
Statistics show that engines very rarely fail these days, yet do any of us not sense a slight difference in the sound of the engine as we set out over a large expanse of water or over mountainous terrain. A slight PPL twitch?
Whether flying at night is statistically more dangerous than flying in daytime, I don’t know. Does anyone?
Flying over the Alps? If I was an insurance assessor I think I might be tempted to add a little to the premium.
As PIC’s we have a choice as to what is and what is not an acceptable risk.
@Peter flies high (normally) over the Alps to mitigate the risks he feels there are in crossing the Alps. And as the OP for this thread, I expect his risk acceptance of flying them at night is also low.
Others would not fly without a parachute.
No amount of trawling through statistics and posts telling me that if I crash my twin I am more likely to die than if I were to crash in a single will make me feel less at ease when flying from the mainland to Corsica at night in a DA42 than I would in a DA40.
The same is true for a night flight over the Alps.
We are PIC’s and whatever we fly, we have sole responsibility to assess the risks that we will face on any upcoming flight and to manage those risks accordingly. As individual pilots it is our choice alone whether we go when we go or whether we don’t go at all.
gallois wrote:
Statistics show that engines very rarely fail these days
Yet that’s what pilots fear most. In reality only a fraction of fatal accidents is caused by an engine failure. There are mid-air collisions, CFIT and takeoff and landing accidents. The risk of these might be less at night than in bright sunshine. Why?
You won’t find yourself in a flock of gliders at night also the Sunday afternoon 100€ coffee flyers are back in their nest by sunset. So much reduced risk of mid-airs at night. Plus at night strobes help a lot to see traffic.
For CFIT, I suspect that some negative risk compensation is at work because one has to assume to not be able to see the terrain and thus plan with much higher margins to stay away for sure. At least I would. Referring to the thread title that would mean at least staying above the mountain ridges.
Finally, at least where I live only the larger airfields with instrument approaches are open at night. These tend to be less challenging for takeoff and landing because there is simply more space around them and less potential for nasty rotors and downdrafts.
So, while this is pure speculation I suspect that a properly planned night flight in good weather from say EDEF to EDDS is safer than a good part of the Sunday afternoon coffee flights. But I’m happy to be corrected on that with some real numbers.
