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rnzoli
27th Aug 2016, 17:22
Hi, if there is anyone,who flew over mountain passes and ridge lines at or above 2000 meters/6500 feet, I would appreciate having a look at my recent flight, which went differently than planned. Was that a close call, or just normal thing to expect in mountains? It was an awsome sight and I don't think safety was compromised, but the gap between the cloud base and the ridge was a bit too little for comfort, at least for a first-timer in that environment.

Events started to unfold at 5 minutes on the video, and I was on the other side by the 8th minute, so those 3 minutes are interesting.

https://youtu.be/UY-fumzZ_wY?t=5m0s

Maoraigh1
27th Aug 2016, 20:41
All my flying near cloud is at lower level ridges in Scotland, and my higher altitude ridge crossings in US were cloud-free.
I take it you knew which side the downdrafts would be on.
I take it you were prepared for steep descending 180 turn.
You could see what you were flying into. It's your choice how confident you are in the cloud forming and downdraft predictions.
But I'd never take my attention off what's happening around me to take photos in that sort of situation. And I'd like to fly around near the ridge before going that close, to confirm wind effects.

Gertrude the Wombat
27th Aug 2016, 21:27
That looked to me far too much like risking flying in cloud below MSA - there's no way I would have been there (would have chickened out long since or been at MSA, which I take to be 2,000', not 1,000', in mountains). Still, we all have different attitudes to risk, it would be boring if we were all the same.

rnzoli
27th Aug 2016, 21:43
I take it you knew which side the downdrafts would be on.Well, I have to confess, having a favourable forecast of only light 5 kts winds and none to few clouds at 8000 feet, I planned to cross at 7500 feet, 1000 feet safely above the ridge, where this wouldn't have posed a big risk. When the cloudiness that greeted me was different from forecast, at that point all I knew I had a tailwind (and this explains the cloud formation on the south side, where I was approaching from, and the fewer clouds on the other side). However, I definitely noticed the smooth ride towards the ridge, so I instintively prepared for the turbulence and downdraft after crossing, which was still pretty violent. Makes me think about how it is in case of moderate to strong winds....
I take it you were prepared for steep descending 180 turn.
You could see what you were flying into. It's your choice how confident you are in the cloud forming and downdraft predictions. Actually the plan was for a 180 level turn at 45 degrees bank, on instruments, and then a straight descent out of the cloud, if I get into one. But this I delayed until losing sight of the ridge, which didn't happen.

But I'd never take my attention off what's happening around me to take photos in that sort of situation.Yes, I hear you, it looks annoying on the recording, even to me! Loose object in the cocpit etc. My only excuse that my attention wasn't divided much, as the picture shots were made without looking into the finder or anything at the camera in fact. Just "blind" shots at whatever the camera can see and capture in automatic mode.

And I'd like to fly around near the ridge before going that close, to confirm wind effects.Good point, many thanks.

DeltaV
28th Aug 2016, 07:59
OK, it was a bit tight scudrunning but from your replies to Maoraigh1 it seems you were sufficiently aware of the potential for disaster, downdraft and turbulence on the lee side.

The point I think Maoraigh1 was making about a descending turn is that you were right in the cloudbase and that by descending you would have much better visibility to see any hard bits you would not want to hit. Your idea of a level turn on instruments gives me the chills and in all such cases I would opt for good sight of the ground features over just about everything else.

In case there was confusion over Maoraigh1's description of a "steep descending 180", I think he meant a steep 180 but descending, not steeply descending.

rnzoli
28th Aug 2016, 13:23
OK, it was a bit tight scudrunning I was afraid of mentioning the dreaded word of "scud running" (#1 VFR pilot killer), but a little bit of that it indeed was.
The point I think Maoraigh1 was making about a descending turn is that you were right in the cloudbase and that by descending you would have much better visibility to see any hard bits you would not want to hit. Your idea of a level turn on instruments gives me the chills and in all such cases I would opt for good sight of the ground features over just about everything else. In principle I agree, in this case however literally everthing is way too hard to hit at the mountain tops (no soft spots at all), and I made myself familiar with the terrain before crossing, so all the hard bits were to the north of me ahead, nothing behind to the south, so I felt in this specific situation a level turn is less dangerous than a descending one. You can see how reluctant I was giving away altitude when approaching the ridge, as I rather manouvered horizontally to avoid clouds in my way, in order the keep my altitude "reserve" over the ridge.

In case there was confusion over Maoraigh1's description of a "steep descending 180", I think he meant a steep 180 but descending, not steeply descending. Thanks, I misunderstood that a little bit too. :) Approching the crossing, I made a mental note of not overbanking the aircraft in case I hit a solid wite-out IMC cloud. I was afraid of G-stalling it with a too steep turn, which is also a bad bad thing in clouds by a VFR guy.

RatherBeFlying
28th Aug 2016, 16:48
Up to and directly above the first ridge you were benefitting from an upslope wind.

After crossing the spur ridge you dumped yourself into the nasty stuff downwind of the ridge crest.

Perhaps you could have stayed on the good side of the spur ridge and turned back on course when over lower ground.

Talk to the local glider pilots.

Overflying the cumulus can also work if you know the clouds thin out over lower ground.

funfly
28th Aug 2016, 16:49
So, is it smart to take chances?

FullWings
28th Aug 2016, 17:53
It didn’t raise my eyebrows watching as there were always options. Personally I might have gone in a fraction lower to give myself better forward visibility and reduced the likelihood of flying into cloud. After all, if the cloud’s below the ridge line you’re not going through low-level anyway.

Another thing to watch is cables, antennas and that kind of thing. Not always marked on the chart and can suddenly appear out of the gloom if you’re in the cone of poor vis around cloud base.

Here’s one from a few years back, just fitted through the gap and no engine either!

http://www.fly13.co.uk/Euro2003/Jun6/Brenner.jpg

mary meagher
28th Aug 2016, 18:25
Lovely picture, full wings! you are braver than I, or you knew the territory very well indeed.

Although I have flown from time to time in mountains, always had a bit more margin. In the Alps, no matter how close you fly to the mountain to get the best lift, coming round the corner there was always a French glider even closer to the rocks!

And going up the valleys - we flatlanders were thoroughly briefed before heading that way, where we could find landable fields.

One flatlander was following another glider flying into a deep deep valley, every minute becoming more interesting, but expecting the French glider would know the territory and so following him he would be safe. About then, the French glider deployed his engine (which had been stowed in the fuselage) and climbed away....

FullWings
28th Aug 2016, 18:41
Well, there was a fair amount of cross-checking of maps and GPS before committing to nipping through.

Here’s some more cumulo-granitus:

http://www.fly13.co.uk/Euro2011/D4/D4_9795.jpg

http://www.fly13.co.uk/Euro2011/D4/D4_9805.jpg

mary meagher
28th Aug 2016, 18:44
rnzoli, I have now taken the trouble to look at your video. The only thing I can say is you are lucky to be alive. Don't ever take innocent passengers along on that sort of suicide flying!

Is it your aircraft? does the owner know you scrape mountainsides in IFR? Grow up!

rnzoli
28th Aug 2016, 19:09
Perhaps you could have stayed on the good side of the spur ridge and turned back on course when over lower ground. Good point, it would have given me better safety margin with an additonal 100-200 feet clearence.

Overflying the cumulus can also work if you know the clouds thin out over lower ground.This actually crossed my mind briefly, but I didn't know what was waiting on the other side, and I was afraid of getting stuck above the clouds. Of course later I realized the clouds were generated by the updraft on the upwind side, so subsequently fewer clouds were on the other side. Next time I'll be wiser :)

rnzoli
28th Aug 2016, 19:20
Another thing to watch is cables, antennas and that kind of thing. Not always marked on the chart and can suddenly appear out of the gloom if you’re in the cone of poor vis around cloud base.Oh, this is so true... Many of these area can be planted full of transceiver towers, masts. Normally lit by red navigation obstacle lights, but still better to see them clearly in advance. Now I start to wonder if it would have been better to reconfigure the aircraft for a slower flight, increase RPM and in exchange, go a bit lower to see better. More time to look, more time to decide, better climb rate with the advance of the throttle, tighter 180 if needed, and less prone to turbulence on the downwind side...

helisdw
28th Aug 2016, 19:24
rnzoli,

This video might not have raised FullWings' eyebrows, but it certainly got my attention!

Although I'm a helicopter pilot, basic mountain flying technique holds true regardless of the machine you're flying so hopefully you don't mind some feedback from a rotary wing driver who spends his time in the mountains of western Canada.

When approaching a ridge line like this, I'd always recommend losing altitude to below the ceiling/cloud bases well before reaching the mountain - you improve forward visibility and avoid avoid entering cloud like you did approaching the mountain side. It's hard to know what the clouds are doing behind the 'wispy' parts you were scud running - as it happens on this occasion they disappated but they could have equally worsened and I suspect this would have then have had a different outcome.

In questionable visibility you should fly an approach other than 90 degrees to the ridge line - typically 45 degrees is advocated. Flying offset/parallel to the ridge gives a number of advantages: you have time to look at the topography of the ridge, you can better judge visibility, you can 'feel' the wind and you have a shorter turning circle to carry out if you don't like what you see or there is an emergency. I'm not sure what your IAS was but even at a modest 100mph you don't have too long to make decisions and action them when flying directly at cloud +/- mountain.

In this case there was a clearer bright area with lower ground to your right - this would have been my choice of area to attempt a crossing, especially as there was falling ground to use as an escape route. Always leave yourself an 'out' for as long as possible and only commit to the crossing when you're sure that what lies beyond the ridge is VFR.

As RatherBeFlying mentioned the wind was upslope as you approached and you got on the 'backside' after crossing - in stronger wind conditions you can expect rotor action and down drafts after crossing the demarcation line, so you'd be wise to increase your crossing altitude if the cloud base allows for it. I'd also be cautious about relying on forecast wind speeds around mountains - they often generate their own unique weather and winds can be significantly stronger (or lighter) than anticipated.

funfly
28th Aug 2016, 20:52
As I can bear witness from flying in Snowdonia, there is another hazard waitimg for you and that is sometimes ferocios down draughes around mountains which can catch you unawares.
And Im not just being a killjoy.

rnzoli
28th Aug 2016, 20:58
so hopefully you don't mind some feedback from a rotary wing driver who spends his time in the mountains of western Canada.Absolutely not, as a low-hour hobby pilot I am very grateful for all constructive criticism from experienced people.
When approaching a ridge line like this, I'd always recommend losing altitude to below the ceiling/cloud bases well before reaching the mountain - you improve forward visibility and avoid avoid entering cloud like you did approaching the mountain side. Point taken! I was afraid of losing altitide and then unable to cimb, but now I know I could have gotten around the aircraft to climb again when needed.

questionable visibility you should fly an approach other than 90 degrees to the ridge line - typically 45 degrees is advocated. Got it, very logical why.Next time I plan this from the beginning.

In this case there was a clearer bright area with lower ground to your right - this would have been my choice of area to attempt a crossing, especially as there was falling ground to use as an escape route. Actually the terrain elevation on my right was 40 feet higher, I checked these from Google Maps before my trip. So I kept it as my 2nd option in reserve. I found this picture from east to west direction of the area, the peak in front is Derese, the distant one is Skalka, and I passed in between them, from left to right. https://goo.gl/maps/SwF7qb6Fm4J2

As RatherBeFlying mentioned the wind was upslope as you approached and you got on the 'backside' after crossing - in stronger wind conditions you can expect rotor action and down drafts after crossing the demarcation line, so you'd be wise to increase your crossing altitude if the cloud base allows for it. Very true. After crossing, I was still under the "mental" pressure from the low cloud base on the upwind side, and I started to descent nearly immediately. Now I understand I should have climbed for a little while, there was sufficient room for that on the downwind side.

mary meagher
29th Aug 2016, 06:19
helisdw, I am well impressed by your excellent summary of safe mountain flying! And in helicopters! your advice is exactly the same as we learned when flying gliders in the Alps and in Spain. You might enjoy sometime having a go in that challenging environment without an engine! I believe gliders can be found in Canada, as well as Europe, or New Zealand, with wise instructors available. Experience counts a lot in that environment.

twochai
29th Aug 2016, 15:14
Actually the plan was for a 180 level turn at 45 degrees bank, on instruments, and then a straight descent out of the cloud

Speaking as one with several thousand hours experience contour flying in the Andes, the Rockies and in the Himalaya ranges, I cannot imagine a more irresponsible strategy.

There are old pilots and there are bold pilots, but ..........

RatherBeFlying
29th Aug 2016, 15:38
Overflying the cumulus can also work if you know the clouds thin out over lower ground.

This actually crossed my mind briefly, but I didn't know what was waiting on the other side, and I was afraid of getting stuck above the clouds. Of course later I realized the clouds were generated by the updraft on the upwind side, so subsequently fewer clouds were on the other side. Next time I'll be wiser Forecast, reports and satellite will give an indication of where the clouds are. Mind you, in the mountains, afternoon weather tends to get active. There's a reason for "Alpine Starts".

You need to learn local weather patterns and fly when the weather is in your favor.

Overflying cloud you do need fuel to turn back to good weather if you can't find a way down. Just be very sure it won't close in behind:=

If you seriously screw up the drill is to get over low ground and high ceilings before thinking of a descent. ATC needs to know. If all goes well, the paperwork will be waiting :E

rnzoli
29th Aug 2016, 19:03
Forecast, reports and satellite will give an indication of where the clouds are. Mind you, in the mountains, afternoon weather tends to get active. There's a reason for "Alpine Starts".

You need to learn local weather patterns and fly when the weather is in your favor. Well, this was my 4th attempt to go, cancelled the other 3 due to questionable weather outlook (one was airborne cancellation). I asked the nearby airport owner (a pilot himself) on any good-to-know gotcha's, I regularly watched the weather against the forecasts several times on webcams on the nearby ski slopes, matched fairly well. This was supposed to be nearly cloudless day by forecast, and at 9 AM, I got a confirmation from Jasna (on the downwind side) that the weather is looking excellent for flying. I was warned en-route about gliding competition in the area. And then I saw what you saw...:ugh: Looks like mountain weather can sometimes trick even the most experienced locals, can't assume anything.

Overflying cloud you do need fuel to turn back to good weather if you can't find a way down. Just be very sure it won't close in behind:=

If you seriously screw up the drill is to get over low ground and high ceilings before thinking of a descent. ATC needs to know. If all goes well, the paperwork will be waiting :EI actually had 3/4 of the tank at that time,and refill of 1/4 of the tank was waiting for me at destination,thinking about the return legs too. I could have even been holding for an hour if I had been sure it was temporary, but it looked getting worse. There is a controlled airspace from 8000 feet there, and I think the clouds tops reached that. ATC (FIC) already knew about the my problem, I told them about the clouds at 4:34 on the video. So if I needed assistance for entering the controlled airspace, they would have surely helped, and also they could have prepared all the incident reporting, personal interview/testimony schedule and suggested traffic fine in a very smooth manner. :} But when I wanted to see first, what the situation was below the cloud base, I slipped through...:confused: ...and this is why I am here now.

Eric Janson
30th Aug 2016, 14:16
I'm surprised nobody has commented on the last part of your video.

First approach high - go around was the correct decision.

Second approach had you floating down the runway (too fast on approach?) and it looks like you touched down at the halfway point. You almost ran off the end - very poor judgement to continue this landing imho.

I was taught to land in the first third of any runway and use the second third for braking with the final third as a reserve.

rnzoli
30th Aug 2016, 14:51
I don't know what the synoptic situation was, but the evolution/origin of your forecast may be of interest.
It would be great if you could have a look at what went wrong with my weather forecasts.


The ridge crest crossing took place here, from South-East to North West direction on 20th August, around 13:15 CET = 11:15 UTC:https://goo.gl/maps/1NLvF17sadS2

This is the synopic chart for that day (00:00 UTC) - to my inexperienced eyes, it looks like a quiet situation, being about 48 hour from an incoming cold front from the West.
http://web.t-online.hu/rnzoli/pdhe20160820_0000_Europe.jpg


My forecast was taken from METEO.PL (http://www.meteo.pl/index_en.php), model UM, 4km grid.


The location of the forecast was the little dark rectangle marked by red arrow, the map refers to it as X=220, Y=493.
http://web.t-online.hu/rnzoli/20160820-Wx-FC-Low-Tatras-location-493-220.png

The last forecast I looked at was this - looks like a great day, high clouds only, and maximum 5-6 octas.


http://web.t-online.hu/rnzoli/20160820-Wx-FC-Low-Tatras.png

Last TAF from a regional airport 50 km East - this one looks great too, only few clouds, but there was also a hint of SCT clouds at 4500 feet with probability of 40%, however, no BKN or OVC clouds at all.

201608200500 TAF LZTT 200500Z 2006/2106 28004KT CAVOK
PROB30 TEMPO 2006/2007 6000 NSC
TEMPO 2007/2016 22007KT 9999 FEW050 SCT090
PROB40
TEMPO 2011/2015 SCT045 FEW060TCU=


Any thoughts what may have been overlooked, or what could have given the hint of so much cloud, i.e. a near overcast at 6000 feet over the ridge? Only the "mountain effect"?

rnzoli
30th Aug 2016, 15:17
I'm surprised nobody has commented on the last part of your video.

First approach high - go around was the correct decision.

Second approach had you floating down the runway (too fast on approach?) and it looks like you touched down at the halfway point. You almost ran off the end - very poor judgement to continue this landing imho.Thanks Eric, it was obvious for me what was wrong with that landing and that's why I didn't ask commenting it. But you are right, it would have been safer to go around. You probably heard the conversation with the ground (Miro is a pilot himself), and RWY 26 is considerably more difficult due to higher terrain under approach path. I was actually on the speed I wanted, and considering density altitude (2000 feet, +20 degrees Celsius), TAS and GS (no wind) was about 10% higher than IAS. A tricky thing is that the runway is higher in the middle (+2 meters, 641 m ARP, 639 m for thresholds). Long story short, I was just about to move the throttle forward when the a/c firmly settled on the main gears, and I felt that I could stop on the tarmac. That's what happened, and there was one more reserve: 50 m of published CWY at the end of both runways, hard ground covered with dense grass. If unable to stop on tarmac, I simply don't turn but continue onto CWY with stick back and limited braking. The problem: what if I get a brake failure... so that landing is definitely not to be repeated again! :=

RatherBeFlying
30th Aug 2016, 19:07
You seem to have made a commendable preflight effort to assess the weather:ok:

Mountains make their own weather - and often fools out of forecasters, including those who put too much faith in the forecasts:uhoh:

On one night flight over the Alleghanies, the forecast was "high scattered FL 330"

- which held until I found myself inside cloud at 6500':\

27/09
31st Aug 2016, 01:38
My comments.

I would have either climbed above the cloud for the ridge crossing or descended to give better forward visibility. There appeared to be a much better option out to you right, a lower part of the ridge and better visibility, which I suspect you didn't notice as you were looking directly ahead. Had you been lower it would have been much easier to spot.

Flying through those wispy bits of cloud isn't a good idea. Get below the cloud to get a better look ahead and around you. You will have a much better idea of whether or not to proceed. Sure you may need to climb a little to cross the ridge later on, but probably not if the conditions are suitable for you to cross.

Going high is going to give a better ride on the leeward side. Though to be honest the turbulence you encountered didn't look too bad. You can expect far worse in some situations. As a rule of thumb if the winds are more than 10 knots down low (say at a nearby airport), don't fly in the mountains, or if you do, be prepared for turbulence and know where to expect it and how to deal with its impact.

As for climbing above the cloud and knowing it its clear on the other side. If you start off low you should be able to see through to the other side of the ridge at some point. If there is plenty of sunshine on the ground on the other side then there should places to descend.

Always approach a ridge at well less than 90 degrees. There's no one perfect angle to approach the ridge at but lets use 45 degrees for this example. If you need to turn a way, depending on the surrounding terrain, a turn of a little more than 45 degrees will take you away from the terrain. With a shallow angle you have more time to assess conditions on the other side of the ridge.

Particularly if your are on the windward side you can fly along the ridge to pick the best point to cross. If you are on the lee side if you encounter a downdraft it's much less risky than approaching the ridge head on.

I'd also like to comment on your landing. Firstly congratulations on deciding to go around the first time.

I need to ask why you didn't fly the circuit for the same runway but elected instead to reposition for the opposite runway? Why did you chose Rwy08 for the first approach and not the second? As you said yourself the approach for 26 has issues. Be repositioning like you did you are setting yourself up for a non standard situation at an unfamiliar airfield. For many low hour pilots just landing at an unfamiliar airfield is enough for them to be out of their comfort zone and make silly small mistakes. Don't increase the risk by doing something non standard.

There are benefits in flying the circuit and landing on the same runway, unless it's obvious you chose incorrectly the first time, then it's not a bad idea to fly three legs of the circuit of the new runway. The benefits are you get yourself properly orientated and ensure you are not doing something non standard and forgetting something or make a mistake.

I know the ATC person said wind calm, that's almost at ground level, what were the prevailing upper winds? These will give you an indication of the possibility of a tailwind on final approach. Bearing in mind local terrain can modify the wind flows. If the wind is calm or fickle choose the runway that faces into the upper prevailing winds, especially if it is short.

Lastly you mentioned you were stabilised on the approach at 65 to 70 knots, yet you seemed to float a long way down the runway, far far further than I as an instructor would have been comfortable with. If I have been sitting beside you I would have instructed you to go around.

What speed did you cross the threshold at? Hopefully not 65 knots. If the figures I have for the Katana DV20 are correct (38 KIAS stall speed full flap) then with full flap extended at all up weight you should be crossing the threshold at 50 KIAS.

Hopefully my comments will be of help to you in the future.

rnzoli
31st Aug 2016, 09:39
2 - winds gusting (?) up to 20 knots blowing upslope onto the ridgeAffirm, the red line is the gust level in their charts.
Hence, my (old-style) VFR conditions look rather unlikely. Many thanks for looking into the details. So I take away that such high-mountain crossing VFR flight should be prepared for
- early morning (before convective activity becomes too strong)
- with anticyclonal high pressure air over the mountainous part of the route
- with only CAVOK or FEW clouds in a sufficiently close TAF (SCT is a warning, BKN OVC TCU CB SHRA, TSHRA are clear no-go's)
- with surface winds in the valleys not above 5-10 kts (average).

Never mind, experience comes from a series of mistakes through life. You have learnt something and got away unscathed. Gruss Gott.Yes, indeed, and actually I chose this airfield and the overfly route to learn something new about such terrain. I was just surprised how steep the learning curve was, but since me and the plane came home together as planned, I am not complaining at all, it's valuable experience for sure, more valuable in fact, than a lucky uneventful flight would have been.

rnzoli
31st Aug 2016, 12:07
As for climbing above the cloud and knowing it its clear on the other side. If you start off low you should be able to see through to the other side of the ridge at some point. If there is plenty of sunshine on the ground on the other side then there should places to descend. Very good point, haven't thought of that.

I'd also like to comment on your landing. Firstly congratulations on deciding to go around the first time. Ah well, it was crystal clear I have too much height. For a moment I thought about side-slipping her in, but discarded the idea. Having a look at the wind sock was a better idea.

I need to ask why you didn't fly the circuit for the same runway but elected instead to reposition for the opposite runway? Why did you chose Rwy08 for the first approach and not the second? As you said yourself the approach for 26 has issues. RWY 08 was chosen initially because my arrival favoured that direction, I was high and from a South-East position I could fly longer alongside the circuit, shedding altitude. Apparently this wasn't enough. After flying over the wind sock, I noticed it was hanging down, but it pointed to reverse direction, favoring RWY 26. So I figured that the last variable wind blew from the west, and I thought runway direction reversal would be a good idea, just to be on safe side and protect from possibility of tailwind. Moreover, there was a model airplane flying at the East end of the runway, so approach from that direction to RWY 26 would be more noticeable for the model airplane's pilot. I only noticed that RWY 26 has elevated terrain all along the approach path when I actually flew the approach and wasn't happy to get too close to the ground. (I didn't know that in advance, altough I checked many pictures and a few videos about the airfield, also overflew it from the opposite direction!)

There are benefits in flying the circuit and landing on the same runway, unless it's obvious you chose incorrectly the first time, then it's not a bad idea to fly three legs of the circuit of the new runway. The benefits are you get yourself properly orientated and ensure you are not doing something non standard and forgetting something or make a mistake.True. Although I said I would make a 45 degree procedure turn back to RWY 26, I actually flew a base leg and a final for the same reason. But yes, ideally, I should have reversed direction on downwind leg only, giving me a chance to settle down, have a closer look at the runway and approach path etc.

Lastly you mentioned you were stabilised on the approach at 65 to 70 knots, yet you seemed to float a long way down the runway, far far further than I as an instructor would have been comfortable with. If I have been sitting beside you I would have instructed you to go around. Will sound strange, but if I had been sitting besides me, I would have done the same :) What I mean is that directional control and the long flare over the narrow and rising/falling runway took great deal of my attention, and I noticed the other threshold coming up, instead of noticing how much runway was already gone behind. That was 1-2 seconds already too late.

What speed did you cross the threshold at? Hopefully not 65 knots. If the figures I have for the Katana DV20 are correct (38 KIAS stall speed full flap) then with full flap extended at all up weight you should be crossing the threshold at 50 KIAS.65 kts I am afraid. We are instructed to approach at 70 kts in general, or at 60-65 kts for short runways. This is to cover windshear, variable winds, distraction or poor monitoring of airspeed etc. And this turns against us when we go for these small places. Especially that RWY 26 threshold seems accessible to a precise flare only by cutting the throttle a tad earlier, slowing down to 55-60 kts over the last part of terrain and then agressively drop in over the 50 m CWY (posibly picking up +5 kts in the process). I missed that, so in reality, I was also 1-2 meter too high over the threshold, contributing to the long flare.

Hopefully my comments will be of help to you in the future. Much appreciated, many thanks.

rnzoli
31st Aug 2016, 12:14
Best wishes, and thanks for you honest account and queries allowing us to ponder a bit and try to offer advice. Most of us do not want to shoot the young down, by the way.Thank you so much, Sir. :ok: This certainly enables me to become a better pilot step-by-step.

I am also updating the video description with the advice I receive, so it might help the awareness of those, who are planning to do a similar flight under similar circumstances.

helisdw
31st Aug 2016, 19:03
Thank you to Mary and EGQL1964 for your kind comments. I'm certainly no expert or a definitive authority on such matters - just a bit of hard won experience from working in and around the mountains. Hopefully rnzoli continues to enjoy his flying and is to be commended for seeking feedback in such a public manner.

Mary - I did fly in a glider from Sutton Bank once; the lack of noise/vibration was somewhat disconcerting!

EGQL1964 - as an expat Scot, I'm certainly used to the weather being less than CAVOK!

RatherBeFlying
1st Sep 2016, 02:09
In an aircraft with an approach speed of 50 kt ( 1.3 x 38 Vso) at full gross, consider that 65 kt = 1.7 Vso.

Landing at 65 kt gives you 70% more kinetic energy to be dissipated by the brakes (with small assists from drag and rolling resistance).

In a healthy 15 kt wind, your groundspeed over the threshold would be 50 and reasonable for the runway in question.

But zero wind combined with a 65 kt approach will have you getting intimate with the other end of the runway - 70% more KE:uhoh:

Flying by yourself with some 2 hours of gas will have you well below gross weight.

I leave it as an exercise for you to calculate:

Square root (LW/MG) x 50 kt

Where:

LW - Landing Weight
MG - Maximum Gross Weight

to determine a zero wind approach speed corrected for weight.

27/09
1st Sep 2016, 02:13
rnzoli: 65 kts I am afraid. We are instructed to approach at 70 kts in general, or at 60-65 kts for short runways. This is to cover windshear, variable winds, distraction or poor monitoring of airspeed etc. And this turns against us when we go for these small places. Especially that RWY 26 threshold seems accessible to a precise flare only by cutting the throttle a tad earlier, slowing down to 55-60 kts over the last part of terrain and then agressively drop in over the 50 m CWY (posibly picking up +5 kts in the process). I missed that, so in reality, I was also 1-2 meter too high over the threshold, contributing to the long flare.


Unfortunately a lot of instructing is either the blind leading the blind or a one size fits all approach.

By all means fly the approach at 65 to 70 knots, but slow up on short finals to a speed appropriate for the conditions. Plan to be at 50' AGL over the runway end/threshold/fence, (as appropriate), at your target threshold speed. This will normally mean reducing power at around 500' AGL plus or minus depending on conditions, aircraft weight and performance.

You should aim for a threshold speed of 1.3 X stall speed for that configuration.

The information I have tells me the DA 20 has a full flap stall speed of 38 KIAS. 1.3 X 38 = 49.4 KIAS. Check your flight manual. You need the wings level, full flap, power off figure in indicated airspeed (IAS).

I would expect anyone who has a PPL to be able to maintain their airspeed by plus or minus 5 knots, you have to be more than 10 knots slower than your target threshold speed before you will stall. You will unlikely to be at MAUW for you landing anyway, so your stall speed will be less than 38 KIAS.

Remember your speed is slowly reducing from 65 to 70 knots at 500' AGL to 50 knots at 50' AGL, so you're not trying to fly along maintaining 50 knots.

Once you cross the threshold don't leave the power on, reduce the power to idle to allow the aircraft to slow and settle onto the runway. Remember to keep increasing the elevator back pressure to stop the nose from dropping. I'm probably telling you stuff you already do here.

Think of every touchdown as the approach to a power off full flap stall that is prevented by the wheels kissing the ground.

You will probably be touching down at about 40 to 42 knots, not that you should be watching the ASI at this point.

If there are wind gusts, add 1/2 the gust factor to your base speed. E.G. If the wind is 10 knots gusting to 20 knots there is a gust factor of 10 so add half of that (5 knots) to your base speed.

How often on the days you fly do you encountered gusty or windshear conditions? You will see from the paragraph above that you need a 20 knot gust factor before you need that target threshold speed of 60 knots.

Fly to the conditions, don't carry any unnecessary speed. Adjust your threshold speed to suit. Keep you hand on the throttle so that you can make prompt adjustments.

Go and try what I have suggested regarding slowing up to a target threshold speed, do it and practice it at a familiar airfield. Once you have it mastered you will be surprised how much less runway and braking action you will need.

27/09
1st Sep 2016, 02:24
RatherBeFlying: In an aircraft with an approach speed of 50 kt ( 1.3 x 38 Vso) at full gross

Remember 1.3 Vs is the 50' or threshold speed, not the approach speed. The approach speed should be reduced to this figure by around 50' AGL.

You make a good point about reducing threshold speed relative to weight.

I haven't done the figures for a while, however from memory for the weight changes involved in most light aircraft the change in Vs due to weight isn't significant enough to have to bother with calculating a new 50' speed.

In the case of a DA20 I think 50 KIAS will work all the time, adjusted for wind gust etc if required.

rnzoli
1st Sep 2016, 11:29
OK, let's do some more analyis for the landing at Jasna! :cool:

I was complacent because I had no trouble landing at a similarly short airfield before, several times. Just looked at RWY lenght, seemed comparable, so instead of calculating landing performance and target speeds, I spent more time with weather checking :p

And then here are the facts.

My earlier experienced short field:
LHJK: RWY 14/32 600 X 18 m, CWY 200 + 200 m grass, ARP elevation 364 ft, no sloping
And the field in the video:
LZJS: RWY 08/26, 544 x 15 m, CWY 50 +50 m, ARP elevation 641 m, 2103 ft (middle), both thresholds at 639 m / 2096 ft. (with grass outline, 644 x 35).

Only 10% shorter, little narrower, but what's the big deal?
Well, it's 1700 feet higher, much shorter clearway at both ends, and I was always there in LHJK with 2 persons (instructor or passager), i.e, greater weight.

Let's check the aircraft actual performance. I took a few screenshots from original video recording and enlarged them to see instruments better:
Aircraft:

weight MTOW 730 kg, approx. actual weight 520 empty +68 pilot +10 baggage + 43 fuel (58 lit) = 641 kg
flaps - landing flaps deployed (confirmed in video at 10:55)
throttle cut at +50 feet/+15m (2110 baro alt), 90 m from threshold, manifold pressure idle (11:55 in video, also correlates to GPS track
threshold - crossed at 63 KIAS at 2080 ft baro alt with VSI 900 fpm (11:59 in video)
wind - windsock on hangar confirm calm (12:02 in video)
flare - flew by taxiway exit at 54 KIAS, 2065 ft baro alt with VSI 500 fpm
touchdown - 41 kts, 2060 ft baro alt VSI 200 fpm, at the 4th outer grass runway marker, which is according to Google Maps, c.a. 360 meters from threshold, (12:11)
stop - came to a halt in remaining 184 meters, giving a total of 90+360+184 = 634 meters from +50 feet/15m point, using 100% runway.


This is what the DV Aircraft Flight Manual (AFM) says for landing performance:
Conditions:

- Idle
- Maximum T/O Mass (Weight)
- max RPM
- Approach speed 59 kts
- level runway. paved
- Flaps in landing position
- Standard setting. MSL

Landing distance over a 15 m (50ft) obstacle: approx. 454 m
Landing roll distance: approx. 228 m (*note by me = this means touch down 454 - 228 = 226 meters from threshold)
For each 750 m (2500 ft) additional height above MSL add 1 0% to the landing distance. (*note by me, the landing roll distance doesn't change with altitude)

So let's adjust this to the actual performance:
Adjustment for MSL: 2060/2500 * 10 = +8.3% 454 * +8.3% = : 491 m landing distance
Adjustment for speed: (65 kts^2)/(59 kts ^2) --> +21% = 595 m
Adjustment for weight = 730/641 = -->+13% = 677 m
Landing point = 677 m-90 -228 =359 m (66% of runway)
Stopping point: 677 -90 = 577 = 587 m (43 meters over end of runway, 7 meters left from 50 m clearway).

Fairly close, the actual landing roll was shorter due to lower weight, clear runway, good traction, hard breaking.

Then how should it have been done well?

Target approach speed for lower weight: Square root (641 /730) * 59 = 55 kts.

This woud give us the following distances in the AFM model:
Adjustment for MSL: 2060/2500 * 10 = +8.3% 454 * +8.3% = : 491 m landing distance
Adjustment for speed: 55^2/59^2 = -13% (491 *0.87 = 427 m)
Adjustment for weight: 730/641 = -->+13% (427 * 1.13) = 482 m
Touchdown point: (482-228 -90 = 164 m from threshold, at 30% of runway length, right at the taxiway exit !
Stopping point: 482-90 = 392 m from threshold, using 72% of runway length)

So in short, 55 kts on approach, cut throttle at +50 ft/15m and I land at 1/3 of runway and stop in the next 1/3, leaving the last 1/3 for reserve. It could have been just like a textbook landing! :ok:


Now let's play more - how about landing at MTOW? Assume I take fat passenger, top up fuel, and after takeoff, he remembers leaving his wallet on the ground. :}

Adjustment for MSL: 2060/2500 * 10 = +8.3% 454 * +8.3% = : 491 m landing distance
Adjustment for speed: 59^2/59^2 = +0% (491 m)
Adjustment for weight: 730/730 = +0% (491 m)
Touchdown point: 491 -228 - 90 = 173m at 31% of the runway
Stopping point: 491-90 = 401 m m from threshold, using 73% of runway length.

No problem either! :D

27/09
5th Sep 2016, 00:49
rnzoli

You've certainly gone and done some homework.

I would make one point about this statement (*note by me, the landing roll distance doesn't change with altitude)

Landing roll will increase with altitude. This is because TAS increases relative to IAS with altitude. Even though you are touching down at the same IAS your TAS hence Ground Speed will be higher and it will take longer to stop.

Otherwise you have done a good job of educating yourself on approach and landing speeds.

P.S.
The 1.3 Vs target threshold speed I mentioned in one of my earlier posts is the the minimum speed legislated for crossing the threshold.

Many POH landing performance figures are calculated using this figure. If this is the case you will need to fly this speed to meet the book figures.

It looks as if Diamond uses a higher figure than 1.3 Vs.

rnzoli
5th Sep 2016, 07:28
Landing roll will increase with altitude. This is because TAS increases relative to IAS with altitude. Even though you are touching down at the same IAS your TAS hence Ground Speed will be higher and it will take longer to stop. Thanks, you're right. The initial kinetic energy will be higher at higher altitudes/temperatures at the touchdown and beginning of the landing roll. But unlike during the flare, at least the deceleration will be based on the friction of the brakes, tires and the pavement, not the rarified air.

It looks as if Diamond uses a higher figure than 1.3 Vs.
Yes, they do, I believe because of the very light construction of their planes, they want to keep at least 20 kts between Vso and recommended final approach speeds. Looking at their aircraft family, the higher the weight of their plane, the closer they get to 1.3 x Vso.


DV20 Diamon Katana (MTOW 730 kg)
Vso= 38 kts
Approach speed = 59 kts (1.57 x Vso)

DA40 Diamond Star: (MTOW 1200 kg)
Vso = 52 kts
Approach speed = 73 kts (1.40 x Vso)

DA42 Diamond TwinStar ( MTOM 1999 kg)
Vso = 64 kts
Approach speed = 86 kts (1.34 x Vso)

Flyingmac
8th Sep 2016, 10:14
I think you should have handled that ridge crossing differently, but I also think you've learnt from it.:D We've all squeezed things a bit tight. Happy flying.

rnzoli
8th Sep 2016, 17:51
Thanks, apparently I found the spirit of the moutain in good mood and he let me escape with the experience.

But today's tragic news from the same area shows how cruel the same mountains can be and how easily they take away lives, even with experienced pilots... :( :( :sad:

Helicopter crash in Slovakia kills four | Fox News (http://www.foxnews.com/world/2016/09/08/helicopter-crash-in-slovakia-kills-four.html)

Maoraigh1
8th Sep 2016, 20:02
"Late Wednesday". Was it a night flight?

rnzoli
8th Sep 2016, 20:21
Yes, apparently. 11 PM local time.
Original article with google translator.. https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=hu&ie=UTF-8&u=http%3A%2F%2Fliptov112.sk%2Fpad-zachranarskeho-vrtulniku-nik-neprezil%2F&edit-text=

AtomKraft
9th Sep 2016, 17:21
Faced with the what's shown at the start of your video, my first thought was....'no'.

Maybe u planned it all, but I'd never have persisted with the plan to continue into that big mess of cloud, rocks and turbulence and curlover, VFR.

No sensible pilot would. Glad u got away with it, suggest you don't do it again!

(12,500 hours here)

rnzoli
9th Sep 2016, 21:04
Glad u got away with it, suggest you don't do it again!Thanks, I promise I won't! In hindsight, this age-old aviation proverb comes to my mind: "You start with a bag full of luck and an empty bag of experience. The trick is to fill the bag of experience before you empty the bag of luck."

Being unaware of all risks, I unknowingly took a lot out from my bag of luck that day. So I will be careful and will not empty it prematurely.

AtomKraft
10th Sep 2016, 05:18
Exactly!

Pop that one in your 'experience' bag.

On another positive note, maybe by sharing the video, some other pilots can add it to their own bag of experience, without actually taking the risk

rjtjrt
10th Sep 2016, 05:24
rnzoli
Congratulations for having the sense and courage to post the video here and ask the question.
That in itself shows great maturity.
It is a very worthwhile video for others to study in the future.

hoistop
22nd Nov 2016, 11:46
rnzoli,
Here are my 5 cents (with quite some mountain flying experience):
-first, thanks for sharing the video and asking for opinion about tricky decisions you made and also sharing options you were considering and all the planning you did (weather and other info gathered) - it shows me the maturity and professional attitude you are developing. Hovewer, considering options you were thinking about (including 180 turn in clouds close to ridge) I would only agree that you took some stuff out of your bag of luck.


I would suggest that you seriously study pecularities of mountain flying, before you fly near one in the future. Experienced glider pilots with mountain experience might be the best source, as they play with such situations often and there is other reason too: powered, loaded GA plane at high altitude might not have much climb performace left! Maybe study some glider pilots books about flying in Alps (a bible of Alpine flying is Helmut Reichmann˛s "Cross country soaring") - and yes, the author killed himself when he apparently skipped his own advice, when crossing the ridge!
Some very basics:
-do not go perpendicular across the ridge, (45 deg should do)
-allways keep horizontal visibility ahead-not only for terrain and obstacles - on your video, there was no margin in case another pilot, doing same thing, would come close. Visibility must be also behind you - in case of turnback.
-learn about demarcation line
-consider that local mountain winds and clouds can be completelly unpredictable and WX forecast does not help much. Wind is sometimes doing very surprising things- that`s why you never fly along the valley in the middle. etc..etc...
If there is a bridge across a river nearby, go there ocasionally and observe how water is doing over rocks and boulders - at high water and low water. This might give you an idea what wind is doing in the mountains-smooth upstreams, rough areas, vortices, downdrafts and what happends with wind speed increase....
Some real life:
1. gliding happily along the ridge, climbing slowly on upwind side of ridge Cu, I suddenly realised that I fell in a common beginners trap (had 100hours total): clouds became my "ground reference" so I was blown on lee side-but high enough, so I just turned straight into the wind - perpendicular to ridge. But, once into the wind, gentle climb turned into shallow descent, that became more and more worrying. Than, new Cu formed right in front of me, with ridge hidden in clouds somewhere below! (very similar scene to your video) I just kept going straight&level, sank into the cloud uncomfortably (thought it will be only for a few seconds), than a thought crossed my mind, that made me freeze: maybe I forgot to set my altimeter correctly before take-off, so I might be a bit lower than I thought! What followed, were the longest, worst, gut-wrenching seconds of my life. After I-don`t-know-how- many seconds, the sun showed again. Even now, 25 years later, this memory starts my heart pounding.
2. My colleague took off with single engine piston airplane from airfield in the mountains, heading home with two friends - a short hop of 25 minutes, but destination on the other side of the mountains. Mountaintops in the solid overcast clouds, Cb just started forming nearby and moving closely with tailwind. Pilot with instructor rating and quite some hours, but most in the flat landscape.


GPS track showed that plane entered a valley in general direction of intended course to cross mountains, but terrain "climbed" faster than the airplane on full power, until it became too late (narrow) to turn back safely. Plane hit the ground in near vertical position, all three aboard died.


Stay safe and learn from experience and mistakes of others- you will not live long enough to learn from your own!


Regards,


hoistop

rnzoli
22nd Nov 2016, 14:37
hoistop, thank you for your insights. It's been several months since I originally posted this and I haven't been near to real mountains since then :) I am aware of 2 independent flight crews among my aquintances trying to fly to the same area since then one had to chose an alternate upfront, the other had to turn back after some heart-pumping manouvering in a valley and an unsuccessful attempt to fly over the top of the clouds instead. So it's actually not an easy path and everyone is happy to be back home safely. Much of the advice collected from this thread is actually visible in the video description, hopefully serving pilots that aspire going the same route to those mountains.


I, on the other hand, chose to fly some flat-land mission in the autumn (let's leave the mountains for the pros! :) Ironically, it seems no matter what I do, I end up in some trouble. In my case it was fog and low-level clouds, making me fly on-the-top VFR for about 30 minutes. I didn't dare to put the link to that footage up here to avoid getting flamed. So the luck bag is getting thinner and thinner, mountains or not.

Anyways, take care and thanks for advice on mountain flying.

Maoraigh1
22nd Nov 2016, 19:14
"So the luck bag is getting thinner and thinner, mountains or not. "

But the experience bag is MUCH fuller.:D

rnzoli
23rd Nov 2016, 06:38
True and I appreciate that. But this steep learning curve is also intimidating a little bit. I had a misconception earlier that I can chose how steep my learning curve should be. Now it seems the learning curve choses us, and looks like a rather steep one picked me out.
All I want is to fly fun cross-country in nice weather on a regular basis, nothing more, nothing less.But now, for my upcoming 1.5 hour flight, I catch myself collecting VFR approach charts to no less than 3 alternates, 1 foreign international airport, 1 home international airport (both H24), and another one with Pilot Controlled Lighting. THen I talk to a military tower controller, if they can take me in case of an emergency. I even look at Google Earth, looking for long straight highway sections near my planned route, to know where to set down the plane, just in case. And I wil memorize the canopy jettison level location before the flight.

Maybe it's just me, but is there a known way to put back some stuff from the experience bag to the luck back again? :)

RatherBeFlying
23rd Nov 2016, 16:19
Next time you're on a drive look up to see the cunning aircraft traps strewn about by the electricity folks.

Fields don't have as many wires, but driveways usually have a pole line alongside.

I have dropped into several fields and the majority of the time have to plan my approach around the power lines.

Oh yes, never fly through a gap in a tree line. There's a good chance that a wire is there:uhoh:

3wheels
24th Nov 2016, 01:03
but is there a known way to put back some stuff from the experience bag to the luck back again?I know nothing of your age or experience.

However I suspect you had little, if any, practical mountain flying experience when you posted the first video.

If you are still running into difficulties ( stuck above cloud for example) then I wonder if you are biting off more than you can chew at this stage of your experience.

Maybe if there is any doubt about weather/mountains/water crossings etc, you should consider some time with an experienced pilot/Instructor before undertaking these types of flights?

That may refill the bucket!

rnzoli
24th Nov 2016, 08:22
Flying with an instructor is a good idea, but let's face it: it will make us more experienced, with no influence on our "luck bag".
On the other hand, it is also a bit silly from me to ask to be lucky. We are lucky when we aren't well prepared, yet we managed to get ourselves and the plane back home in one piece, undamaged. Flying on the long run is not sustainable on luck alone, that bag will run out eventually. The only way to preserve as much as possible is using the luck factor as little as possible (by learning and preparing better and better).

When it comes to chewing capacity, this is what I try to order
http://images.guidetrip.com/images/uploads/experiences/12253/small-group-gourmet-dinner-tour-of-toronto-s-little-italy-in-toronto-112924.jpg

and this is what the weather serves instead! Of course I have problems to chew those beasts.

http://www.ethanbodnaruk.com/wp-content/uploads/2013/04/giant-hamburger-585x443.jpg



At the root of the whole problem I find that renting planes to fly in the vinicity of the home base has a certain level of costs, but as soon as I want to fly longer distances (say > 140 NM), these costs will increase exponentially, not linearly. This is because the more interesting and longer trips are more likely to run into a greater degree of weather variation, so turn-backs, diversion to alternates, delays and extended opening hours for night arrivals become more and more likely with VFR-only capabilities.

In this situation, I can only foresee 3 alternatives for continuing cross-country flying safely (all require throwing a lot of ore money at flying, of course):

1) Buy a plane and become a freelancer or pensioner = I can easily wait for the tiny number of days when my next planned route is perfect VFR
2) Continue to rent, but do IFR traing and rent higher capability IFR planes for IFR flying, at least en-route = I can go into and above the clouds
3) Continue to rent, but move to another far-away country with more sun and dry air = more VFR days per month.

This is hard to swallow too, but that's the issue behind all of my (near) screw-ups.

Maoraigh1
24th Nov 2016, 22:28
I bought a 1/6 share in a Jodel DR1050 almost 27 years ago. More money for flying hours than if I was sole owner.
I check aviation weather and other weather sites, before flying. I keep a watch on the weather I see as I fly. I often change my plan after take-off. Almost all my flying is in the Scottish Highlands. I have only 3 times diverted to an other airfield.
And every time the aircraft is down for any long maintenance, that is the best spell of weather in the year.

rnzoli
25th Nov 2016, 11:23
And every time the aircraft is down for any long maintenance, that is the best spell of weather in the year.

So true! And also applicable for periods, when the pilot himself/herself is down for maintenance. Someone broke my right hand during a friendly soccer game (very unlucky collision), just one day after I flew over that ridge. (All pilot friends started to make jokes about my soccer playing being more dangerous than my flying.) What followed was the nicest and driest September and early October. When I knew the expected date of receiving clearance of my suspended medical, I looked at the weather forecast and it was destroyed again with fronts after fronts, heavy rain, fog etc. This is how I became 100% confident that I get the clearance from the AME. And I did, just as the bad weather moved in again.