Leaning for high density altitude takeoffs and climbs

[Superpilot]

I'm going to be heading over to the States again for some hour building, this time visiting the South West - Grand Canyon, Sedona and a few other high altitude airports.

Having read some basic guides on mountain flying all of them seem to recommend leaning the engine for takeoff and climb. I was always taught that leaning the engine at 100% takeoff power is plain dangerous.

Any thoughts? Also would be interested to hear from other folks who have done hour building by flying from Florida up to the South West/CA and back again.

Thanks

[Final 3 Greens]

Boy oh boy.

I think that you need some serious time with a instructor before you go near them thar hills, or you are likely to kill yourself.

If you don't lean at high density altitudes, you will not develop full power.

There are many, many, other factors in mountain flying that mandate an appropriate amopunt of time with a qualified and experienced instructor.

[Genghis the Engineer]

True enough on both counts.

None of the rental places in the US will hire you an aeroplane to fly to places like that without a high altitude checkout. Yes you do need to lean for best power (and to stop the plugs fouling), the local instructors understand that those of us who fly in the UK won't have been taught how, and will make sure that you understand it before they let you out on your own.

It actually very interesting - and a new skill as you gently tweak mixture for best power during a slow and ponderous take-off run from somewhere like Grand Canyon.

The other thing is don't forget that power in any case will be far down on what you're used to. So, hire something like a C152 only if planning to fly solo, and something like a Warrior for 2 people.

G

[Ni Thomas]

I tend to echo F3G's comments.
You should really have a chat with an instructor (and preferrably one who has actually experienced the conditions)

Leaning is most important when dealing with these higher altitude airfields. Leaning tothe peak power available is paramount in the conditions you're likely to encounter.
Last year I flew from USA East coast across to California and back (Grumman AA5B - beautiful machine) - Several airfields visited would have proved very difficult if not impossible from which to depart and climb without proper leaning - eg Rawlings Municiple (KRWL - Wyoming) - 7008ft (2156m) of runway. Altitude - 6813ft ASL. Airtemp 115degF - Nil wind. Reported density altitdue 10,000ft! :uhoh:
You'll certainly need to properly understand Density Altitude and the consequences of "Hot & High".
Don't be put off - It's a great country to fly in - This year it's Connecticut (Bridgeport to Texas and back - Yahooo! :O )

[IO540]

As an example, the underlying idea is that Lycoming authorise leaning to peak EGT at power settings below 75% of max rated HP, for certain engines.

So, if the density altitude at departure is such that the engine will not make more than 75% rated power anyway (one needs to refer to the engine performance charts for this, but (on a NON turbocharged engine obviously) it's of the order of a few thousand feet airfield elevation) then one leans - on the runway - for max revs (if fixed pitch prop) or for peak EGT (if VP prop).

So, one needs to understand the engine performance charts, which aren't necessarily provided in the handbook.

And how to calculate the density altitude, given airfield elevation, baro pressure, and temperature. This is done using a slide rule or some other calculator, or using a takeoff performance chart which has curves on it for all these factors.

[Farmer 1]

I believe there are restrictions on flying in the Grand Canyon area, so suggest you check that out before you set your hopes too high.

[Genghis the Engineer]

I believe there are restrictions on flying in the Grand Canyon area, so suggest you check that out before you set your hopes too high.

Certainly are, but they're all shown on the Sectional.

But without restriction, you can fly into Grand Canyon airport (which is just South of the Canyon) and pick up a tour.

G

[Keef]

I've flown in that area quite a few times, and every time I was required to demonstrate an approach, landing, and departure at high altitude (which tended to be Big Bear City). Don't even think of doing it without a thorough briefing and training.

You set full power, then lean for max RPM, before takeoff.

An Arrow III is just about OK with two up and some bags. Even then, your rate of climb might not be much (as we expected, and found).

Learn to do density altitude calcuations: the field might be at 6000 feet, but the DA might be a lot higher.

The Grand Canyon is well worth a visit, but you need the special chart for it - the restrictions are complex, and need studying.

We're off there again in April, ho ho.

[172driver]

Also bear in mind that in some hot/high circumstances you may NOT be able to get the a/c airborne ! Always, always, refer to the charts (density alt, performance, runway length, weight) and REALLY calculate your t/o roll and climb perfomance. Rule of thumb 'ah, she'll be right' is a - potentially deadly - no-no. Also, always use ALL runway avail. And definitely get some time with an instructor over there first. You'll be surprised how a 172 can suddenly feel like a heavy 747 laden to the gunwales :eek: !

PS: I'd also rather rent a 172 (or better still 182) rather than a PA28 for your adventure. The Cessnas have a higher service ceiling - and a bettter view ;-)

[slim_slag]

Any thoughts?

3000ft DA seems to me to be where it's worth taking time to lean properly.

Also would be interested to hear from other folks who have done hour building by flying from Florida up to the South West/CA and back again.


The Rockies are pretty high and not to be underestimated. You will probably want to go on the southern route, so get some mountain flying training in the foothills. Go for as many HP as you can afford, it could get you out of trouble. These 160HP spamcans are not really mountain fliers, though a 150 HP Super Cub is.

[Keef]

3000 ft DA is not at all unusual around California, Nevada etc and in the Rockies. Pete and I landed at places with DA around 10,000 feet. That does test your skills - landing indicates the right speed, but is (and feels) a lot faster. Takeoff is a challenge. Do the sums!

[SkyHawk-N]

I learnt to fly in Cheyenne, Wyoming where it is 6,700 feet above sea level. It is essential to lean the engine during the power checks otherwise you won't get off the ground. I flew a 160hp 172 and on some days it was struggle to get airborne, half filled tanks and a stiff headwind helped. The winds at these altitudes can also be a problem, I once heard a guy on the radio saying that he was finding it difficult to keep a positive ground speed. Bad weather can develop VERY quickly around the Rockies.

I survived it and thoroughly enjoyed it but I was flying with some very experienced local flyers.

[RatherBeFlying]

Watch out on those touch and gos.
Mixture Full Rich is drilled in as a before landing check, but does not work that well in a Grumman Cheetah on a Summer day on a 3000' runway at 3937' ASL.
Was able to see the gophers diving into their holes while building airspeed in ground effect:uhoh:

[SkyHawk-N]

Watch out on those touch and gos.
Mixture Full Rich is drilled in as a before landing check, but does not work that well in a Grumman Cheetah on a Summer day on a 3000' runway at 3937' ASL.
Was able to see the gophers diving into their holes while building airspeed in ground effect:uhoh:

I had exactly the same problem at Cheyenne although with me it wasn't Gophers, it was Golfers! :} (the municipal golf course is at the end of runway 31).

[QDMQDMQDM]

We have had two density altitude accidents at two local airfields in Switzerland in the last two years. One is at 3300ft amsl and the other at 2130ft, but the temp in the summer gets up into the 30s. The strip at 2100 ft amsl is Gruyere, with an 800m + grass strip. A 172 went into the trees at the end four-up after refueling. The other one is Saanen and has a 3000ft tarmac strip. A 152 took off to the East, one-up, and didn't make it over the pass. All on-board were killed in both cases.

DA is a most deceptive killer. You can easily get into a mindset of 'this aircraft should be able to get out of here easily', but 20 degrees in temp will make all the difference. Very sobering.

QDM

[IO540]

All because the PPL does't include training for proper takeoff performance calculation (IME).

[Genghis the Engineer]

All because the PPL does't include training for proper takeoff performance calculation (IME).

Not really, that is supposed to be taught properly. (Arguably it isn't, but that's the fault of the instructor community, not the syllabus).

But why on earth should a UK trained pilot have been taught the skills of leaning for best power take-off at 3000+ft density altitude? It's a particular skill for particular parts of the world which, like for example mountain flying, should be learned when needed. The main thing is to make sure that PPLs know there's a difference.

G

[172driver]

All because the PPL does't include training for proper takeoff performance calculation (IME).
IO540 on the FAA syllabus it certainly does :ok:
But why on earth should a UK trained pilot have been taught the skills of leaning for best power take-off at 3000+ft density altitude?
Ghengis Because airplanes are made to go places, and the world isn't like the UK. At the very least a UK PPL should be aware of the issue (btw what IO540 bemoans - t/o calculations - is a broader field that also definitely applies in the UK. Just read the recurring accident reports of people launching from farmstrips into hedges :( )

[slim_slag]

I suppose in theory a freshly minted PPL could safely fly around the mountains. In practice it's not that simple. For instance, Keef makes a good point, if feels a lot faster when on final. It would be impossible to reproduce that on your average flatland PPL course. Could the UK instructor describe that? Probably not. The first time your new PPL flying the numbers (yeh, right :)) saw his approach he could easily get into a lot of trouble. Climbing out, the sight picture is totally different too, very easy to stall close to the ground and that's not desirable. So in the real world I wouldn't expect a PPL to know how to fly safely in the mountains, which is why I tell them to get some dual with somebody who knows the score. And that isn't a lowland instructor in the US or the UK.

[Final 3 Greens]

''I suppose in theory a freshly minted PPL could safely fly around the mountains.''

Hey Slim - I know you've done a bit of flying in the mountains - no-one has mentioned turbulence yet :} (30 knots over the tops etc....)

I also support Ghengis' view; PPLs can't be taught everything - for instance I don't believe that US PPLs are taught to land using the crab technique.

[slim_slag]

F3G, not sure I would want to be up in the Rockies in a spamcan with 30knt winds around. Belt up and hold onto your teeth. Severe turbulence isn't very common, most pilots (airline and light) overestimate turbulence significantly and it's not often you hit even moderate bumps. But the first time you do hit severe turbulence it's good to have somebody next to you who has seen it before or else you will scare yourself sh!tless (and even then you will probably cack your pants). Not the sort of thing you can learn from a book or most UK PPL instructors who probably shouldn't be out in 30 kt winds themselves.

So look at winds aloft at ridge level and pick a personal comfort level. I'd say for a newbie 10knts is plenty - if they have been up with somebody before. Also check winds aloft for shear, so (for example) if the winds at 9000 are not close to that at 12000 then think about staying on the ground. Contrary to what PPL textbooks say, lenticular clouds don't really prove anything except where the dewpoint is.

When it's calm you cannot beat it.

[englishal]

My tips are obviously to lean for a best power take off, but also don't go full rich on approach in case you need to go around. Rmember that ground speed will be higher on the approach / take off as well, and make any decision to go-around early. Also watch the weather as sometimes its better to go in / out early or late in the day. Depends when you're going of course, in the high desert area it can get quite cold so its not always an issue of high DA. I'd say that no more than two up in a PA28 fueled to tabs or less to get into places like Big Bear in the summer and even that might be pushing it. I watched an Arrow leave there one summer and it bearly got off the ground, and hardly climbed at all.

Make sure you have your backup plans in place. E.g. If not airborne by this point on the runway, abort, no question. If you get off and are not climbing, make sure you have studied the chart and follow any ground that is dropping away (like a road)......

There is an urban myth of two airline pilots who rented a 172 and flew to Meteor crater in AZ, then flew into the crater but couldn't get back out again as they couldn't climb while turning (to avoid the crater walls) and had to ditch it in the bottom. Don't know if it is true or not, but it makes a good story.

[Genghis the Engineer]

chart and follow any ground that is dropping away (like a road)......
There is an urban myth of two airline pilots who rented a 172 and flew to Meteor crater in AZ, then flew into the crater but couldn't get back out again as they couldn't climb while turning (to avoid the crater walls) and had to ditch it in the bottom. Don't know if it is true or not, but it makes a good story.

Having flow over it, I'd say its feasible. Certainly it's an overflight I'd strongly recommend to anybody visiting Arizona, as is the range of extinct Volcanoes to the NW of there (sorry, don't have my charts to hand to tell you their names).

G

[slim_slag]

That would be Sunset Crater Volcanic Park http://www.nps.gov/sucr/. Speaking of turbulence, you get a lot of thermal based turbulence up there during the summer afternoons. Even though it's sort of flat up there (yeh, I know there is a 12000ft mountain within 10 miles), it still can get pretty rough. The plateau is around 7,000 feet ish and the capping layer can easily be above the oxygen levels so you just have to sweat it out. Best to fly early in the morning when it can be nice and smooth.

[SkyHawk-N]

This web site may have been mentioned on PPrune before but just in case ... http://www.mountainflying.com/

I've never been near one myself but encountering a rotor is supposed to be interesting :eek:

[IO540]

englishal

I've walked around the Meteor Crater, and frankly anybody who wants to do a descending orbit into it is a d1ckhead :O

I suppose somebody could calculate the bank angle required to remain inside it, for an aircraft flying at its Vy, say 85kt, and it might be only a 5 degree bank, but it is still pretty stupid.

It's like that bunch of Bonanza pilots who took off together into a canyon and several of them flew into the end of it - being unable to outclimb it. I believe that to be true but don't know the date. There's always somebody.....

[172driver]

It's like that bunch of Bonanza pilots who took off together into a canyon and several of them flew into the end of it - being unable to outclimb it. I believe that to be true but don't know the date. There's always somebody.....
I guess what can really catch you off guard the first time in a hot/high situation is the lack of power in a normally aspirated engine. If you've only ever flown around sealevel in relatively standard temps, this can be a very nasty surprise.

Not confined to high altitude, btw. Will never forget a t/o from LEZL (alt something like 50 ft) in 48 deg weather (yep, that's centigrades !) in a fixed-pitch 172. Was alone on board but it felt like I had a bunch of stowaways hidden somewhere. Interesting. :eek:

[drauk]

Whilst I wouldn't necessarily disagree with any of the factual information presented in this thread, I do think it is worth pointing out that this stuff isn't insurmountable. Read the books on the subject, study the charts, study the POH, do the calculations, get the weather briefs, etc., but don't be put off!

[White Bear]

F3G:
I also support Ghengis' view; PPLs can't be taught everything - for instance I don't believe that US PPLs are taught to land using the crab technique.

Absolute Rubbish!
Regards,
W.B.

[Genghis the Engineer]

Absolutely, most FAA PPLs are perfectly capable of flying a crabbed approach.


If you wanted a more sensible comparison, most American PPLs are not taught about the joys of flying into short muddy grass strips. Ah, bugger, the **** stupid British requirement for licenced airfields means that most British PPLs aren't either - damn.

Mountain flying is probably the best example - we have plenty of it here in Britain as well as in the US, it's not in either PPL syllabus, but I don't think pilots trained in either country are unaware that there are risks and differences involved and if they are going to try, they should go and get some specialist training.

G

[slim_slag]

FAA recommends teaching wing down landings. I'd never considered Britain to be particularly mountainous. Beautiful scenery for sure and definitely extreme weather in places (on the blizzard side when you shouldn't be out anyway), but mountainous? How often do you get a 3000ft DA day on tyhe ground? I guess it's all relative.

[Gargleblaster]

Re. density altitude, we have the opposite situation here in DK. Went flying Monday, airport elev 146 feet, QNH 1047, temp -9 C, density altitude MINUS 3755 feet ! I lifted off almost immediately !

I have done some mountain flying (not in Denmark :-)), you have to be very careful, especially in passes and on the leeside of mountains. The aircraft I flew had a patched rear window, on a previous flight half of the baggage had departed the plane that way.

[172driver]

Whilst I wouldn't necessarily disagree with any of the factual information presented in this thread, I do think it is worth pointing out that this stuff isn't insurmountable. Read the books on the subject, study the charts, study the POH, do the calculations, get the weather briefs, etc., but don't be put off!
Absolutely! Couldn't agree more, mountain flying is great. So by all means, do your preps and enjoy the ride. Just be careful up there :ok:

[Final 3 Greens]

"Read the books on the subject, study the charts, study the POH, do the calculations, get the weather briefs, etc., but don't be put off!"

I find your positive attitude to be admirable, but would like to add that what really brought it all home to me was actually experiencing flying in and out of a 6,800' field with an experienced instructor.

All the briefings and self study in the world won't really prepare you for what it looks and feels like to use 4,000 feet of runway to get airborne in a Arrow, the picture out of the window related to the ROC and the crazy feeling that comes from watching what appears to be a ridiculously high groundspeed in relation to the ASI (judging by UK standards.) It's experiential stuff.

I had a great teacher and he convinced me that mountain flying was a wonderful experience, but intolerant of the ill prepared.

So by all means do all the above that you suggest, but also fly with someone who knows the territory and let them transfer their years of knowledge - its very good value for money.

Not only will it make you safer, but you'll learn more quickly how to enjoy this wonderful experience.

To give interested people a feeling of how great mountain flying can be, the link below documents a flight up to Big Bear (which Keef mentioned.) Its less than a couple of hours flight from the LA basin and is a beautiful ride... Note the comment about the 'short field takeoff' that used ''less than half of the 1 mile long runway!''

Big Bear is in the Sierras, which are pygmy relatives of the Rockies where Slim Slag has flown - the Rockies top out at about another 4,000 ft above the Sierras, IIRC.

http://www.scottkurowski.com/photos/BigBearBreakfast/

[slim_slag]

Ah F3G, a common misconception. The highest mountain in the lower 48 is Mount Whitney in California. The Sierras are a significant barrier to light aircraft, that's why Banning Pass and Donner Pass are more "household name" than you might otherwise expect.

Far more interesting flying in the Rockies though :)

[Final 3 Greens]

Slim

Thanks for your info about the rockies and sierras, I guess that I only saw the smaller ones then - I see that Mt Whitney is well over 14,500' - that's pretty big.

Talking of passes, the Cahun has its moments too. I got really blown about by the Santa Ana on a blowy day - and that was in a car :} , thank god I was terra firma.)

[Genghis the Engineer]

FAA recommends teaching wing down landings. I'd never considered Britain to be particularly mountainous. Beautiful scenery for sure and definitely extreme weather in places (on the blizzard side when you shouldn't be out anyway), but mountainous? How often do you get a 3000ft DA day on tyhe ground? I guess it's all relative.

Fairly rarely, but there may be far more occasions where there are mountains between you and your destination and you might consider flying through rather than well over them (particularly given the typical British cloudbase). That's what I meant by mountain flying.

G

[Final 3 Greens]

I'd call what Ghengis describes as hill flying, but that is not to under estimate the challenges and there are certainly some considerations to think through very carefully before doing it. Inattention to detail could be terminal.

But not quite the same level of challenge as the Alps or the Sierras, IMHO.

[slim_slag]

I'd call it scud running :) If you know the area and climate well then fair enough, but not to be recommended to somebody just passing through. Yeh, the Cajon pass can get rough when the winds are up.

[Genghis the Engineer]

I'd call what Ghengis describes as hill flying, but that is not to under estimate the challenges and there are certainly some considerations to think through very carefully before doing it. Inattention to detail could be terminal.
But not quite the same level of challenge as the Alps or the Sierras, IMHO.

Having as a rather younger and more inexperienced pilot decided to route down a sea-loch at 1000ft, with multiple 3000ft peaks either side, it wasn't the term I'd have used having just about kept control enough to do a 180° and get out over open sea!

G

Not a mountain pilot, I have known since.

[Final 3 Greens]

G

One can certainly win a Darwin award very quickly in any hilly area , so no 'vertical snobbery' or 'mine is bigger than yours' issues here. Its just that density altitude makes such a difference to the capability of a light single without turbocharging, so you have to be a long way ahead of the aeroplane in knowing the alternatives available and what can and cannot be done, in the event of wx changes or other external factors.

If you have to force land, you're that much higher too, so survival planning is even more important.

I don't consider myself a mountain pilot either, I've just been lucky enough to spend some beautiful hours in the sierras and san gabriels.

[Genghis the Engineer]

I'd venture that there are two separate sets of skills there.

(1) Flying around mountains.

(2) Flying from airports with high density altitudes.


Inevitably there are places where you'll have to do both, but they are almost certainly separate skills, only one of which is likely to be regularly practiced here in Britain.

G

[John Farley]

Superpilot

You don’t seem to have come back since starting this thread.

You are of course quite correct that engine manufacturers will not let you lean out their donks at full power. The point is that at high altitude you will not get anything like the full rated power output so leaning comes into the picture to make the most of what you have.

Mountain flying is very different from simple (flattish ground) high altitude flying. Beware. NB what Genghis said while I was writing this.

If you want to see the sort of difference in power you will have doing a high altitude takeoff when you only have a low altitude airfield to fly from you will get some idea if you do the following:

Take off and climb to the altitude you expect to fly from. Do a full throttle level run and note the IAS when it has stabilised. Now do an early go around from your low level airfield and fly level at the IAS you found was your max at height. Leave the throttle where it is and go to a safe height to mark the throttle position on the quadrant with a pencil.

If you subsequently take off from your low level airfield restricting your throttle position to the pencil mark you will have some idea of what you will be up against from a high altitude airfield.

This is just a guide as it ignores temp effects. High and HOT will be even worse.

[Final 3 Greens]

G - agreed.


Mountain flying is very different from simple (flattish ground) high altitude flying
Thank you, you have found more elegant and clear words than me. This is precisely the point I was trying to make when referring to DA. You lose a lot of vertical flexibility (down) due to the MSA of the terrain and yet are usually performance limited upwards by DA in a light single without turbocharging (i.e. service ceiling limit and also ROC/NM.) Lateral options may be limited by terrain or weather.
So you have to be clear about what options are available, such as passes to descend through etc, in case of unexpected circumstances.
Having said this, I've only done a fraction of the mountain flying that you have ;)

[slim_slag]

I still cannot accept that Scotland has mountains when it comes to light aircraft performance. It may have obstacle clearance issues, but you have the same problem with trees at the departure end of a runway. I think of mountain flying as places where your aircraft performance is degraded by the environment and you are close enough to the ground that you are in danger of hitting it. I don't think you will get significant engine/airframe performance degradation at the altitudes/temperatures found in Scotland. Genghis gives an example of flying below clouds in a valley, I call that scud running, not mountain flying.

What do the regs have to say about it? The only place I can think of where it's regulated is with minimum altitudes when flying IFR. By regulation, when flying IFR in mountainous areas you need to be 2000ft above nearby terrain, non mountainous areas 1000ft. As far as I am aware, the whole UK is classified by the CAA as a 1000ft area. So not mountainous.

It's all relative and not bragging rights material. Just don't think because you fly around Scotland you can fly around Colorado or the French Alps, you still need to go fly with somebody with local knowledge. IMO.

[Genghis the Engineer]

You seem to be of the opinion that aircraft performance at altitude is the main issue with regard to mountain flying?

I'd venture that it's probably the least issue you need to worry about.

G

[slim_slag]

I am all ears :)

[172driver]

You seem to be of the opinion that aircraft performance at altitude is the main issue with regard to mountain flying?
I'd venture that it's probably the least issue you need to worry about.
G
Ghengis, agree and disagree at the same time. It's certainly not the only issue, but it is the one the newbie will be least prepared for. No reading of books, training videos and what-have-you will prepare you for the loss of power available (always assuming you fly a non-turbo a/c). If you then add above-standard temps, as often found in the SW USA or southern Europe in summer.... well it's all there in the accident reports. :(

[slim_slag]

It's certainly not the only issue, but is it the least issue?

[172driver]

slim_slag

It becomes the least issue if you are aware of it / used to it. If you are, you plan and fly differently. Many mountain accidents appear to have as at least one cause (as we all know there's never only one) the lack of power at altitude. In itself not a problem, but the unwary expects the a/c to behave as if it were at, say, 1000ft. Not so.

[FlyingForFun]

Surely the issues which are least/most important depends where your mountain flying is taking place?

Just about all of my mountain flying took place in Arizona, where it is very high in places, and very hot in summer (albeit I was there in winter), but for the most part you can expect blue skies and reasonably calm winds. So although I was always careful to avoid being in the lee of the mountains, and always made sure I had an escape route when flying close to mountains, the main issue for me was lack of power from the higher altitude fields.

I think Genghis' point is that in Scotland it is a different type of mountain flying, where density altitude is rarely a problem, but weather is - therefore the priorities given to the importance of power vs weather would be the reverse of what I experienced in Arizona?

FFF
------------------

[172driver]

FFF

I don't think I would call flying in Scotland mountain flying (w/o ever having flown there, I readily admit).

If, however, you are referring to the fabulous wx this country enjoys in general - you've got a point! ;)

[Genghis the Engineer]

- Adiabatic / Katabatic winds

- Cloudbases below tops

- Rotor

- Turn performance within valleys (ever looked at the chance in turning circle with density altitude, irrespective of power)

- Peak-spanning powerlines and cablecars (not a big problem in the UK here, huge in some countries, in Sweden they have whole research programmes about cable avoidance)

- More rotor, with added nasty turbulence for good measure.

- Standing waves.

- Variable wind headings.

- Emergency landing site selection.

- (In some countries) military training areas, notification and avoidance.

- How to emergency land on a glacier.

- Valley channelling of wind.

Now I'm not an experienced mountain pilot (although I have flown in, over and around mountains in England, Scotland, California and Arizona, so not a total novice), but with my limited experience I know about those. I'm willing to bet that somebody genuinely used to flying in those environments could double my list of critical issues.

All in addition to take-off, climb and landing performance!

A couple of years ago I also had to work out for myself how to handle crossing the plume downstream of a mountain forest fire over mountains. That's one I've not seen in any books either, but perhaps not a common UK mountain problem either (this was in CA).

G

[slim_slag]

Sorry genghis, they aren't "most".

6 our of your list of 12 are related to wind. The real problem with wind in the mountains is being unable to power out of trouble, that's peformance related. Rotors are talked about but don't cause that much trouble in practice, in fact glider pilots will seek them out as they give a good rate of climb. Turbulence is a comfort issue, not common to have a plane break up in mid air. Happens, but not often.

Emergency landing, wires, military training areas, turning in valleys, low clouds, are not specific to mountains, you get them everywhere.

What will kill you in the mountains?

1) Not getting out of ground effect before the runway ends and hitting something. Performance related.

2) Hitting the ground because you didn't get your climb gradient correct. Performance related.

3) Ice/visibility - but a 100ft MSL hill will kill you if you can not see it so it's not specific to mountains. But if you had better performance, perhaps you wouldn't be in the clouds in the first place.

"You seem to be of the opinion that aircraft performance at altitude is the main issue with regard to mountain flying?"

Yes, nothing has changed that opinion :)

[Genghis the Engineer]

The temptation is to argue.

Actually, I think I'll sit and see what everybody else thinks of the two viewpoints with interest.

G

[slim_slag]

Just spent a few days in colorado with some enjoyable hangar flying at a high altitude airport. Universal concensus is that aircraft performance is the major difference between lowland and mountain flying. This comes from people based at these airports flying freight and charter in all seasons, people who have forgotten more than I will ever learn, and who definitely prove there is no substitute for experience. Now in Arizona and will be chatting with some instructors who spend lots of time in mountains and who also know their stuff.