Mountain Flying

[FlyAnotherDay]

Heliport

After asking advice here in Rotorheads, I had six days of mountain training in New Zealand at Simon Spencer-Bower's outfit, Wanaka Helicopters, which I thoroughly enjoyed, couldn't fault and would recommend unhesitatingly. I have a PPL(H) but think that it would be equally good for a CPL/ATPL holder.

FlyAnotherDay

[Heliport]

Pleased the recommendations given on the forum were useful - all part of the world famous Rotorheads service.

Sounds as though it was a very useful course.
Tell us more about it when you have time.


Heliport

[FlyAnotherDay]

Heliport, thanks for the invitation.

As mentioned before, I did some mountain training in New Zealand. I have a UK PPL(H). My flying in NZ was all in R22s and started off more as do-a-bit-of-mountain-flying and ended up with more than I'd anticipated.

Given the usual caveats (the mistakes are all mine and don't try this at home without adult supervision), here's a list-ish sort of summary:

After some briefing, I spent a while flying up and down valleys: Choosing which part of the valley to fly in, to gain lift from funneled wind, to provide space to turn when necessary and to maintain a margin of safety for engine failure, typically 2/3rds up the windward face of the valley. And learning to fly without a reliable horizon, particularly flying up or down a valley: As the valley floor drops away, there's a tendency to accelerate and as the floor rises, there's a tendency to slow, so being aware of these and watching the ASI helps maintain the chosen AS.

In landings, the three most important factors are the S's, the W's and Power:

S's - the Sun, preferably not in your eyes. The Skids - will they fit? And the other five S's I remember from UK confined area operations - Size, Shape, Surrounds, Surface and Slope.

W's - Wind direction, Wires, Way in, Way out, escape Woute and Wubbish

Power: In the UK I'd been taught a straight & level power check to determine Manifold Pressure requirement for landing and a comparison with the placarded max allowed.

Instead, to determine the power requirement: Check the 2’ HIGE MP indicated at T/O. The same indicated MP will be required for HIGE at whatever altitude, higher or lower, although this will correspond to a lower power at lower altitude or higher power at higher altitude, as density varies. However, if you’ve burned a load of fuel, less power and so a lower MP may be needed and so a 53kt S+L power check may be sensible .

Power available may not be as placarded - in flight, pull collective until E+R just start to droop (but are still in the green) and note MP. This is MP available. Remember, the power that a given MP equates to varies with density.

Power available determines whether landing is possible - and how: 53kt S+L +3" for a running landing, +4" for a 0/0, +5" for towering and for the 2' HIGE - as in T/O power check, +6" for HOGE vertical, +7" for vertical.

Fly the landing site recce tightly at 60kts, with the site on your side, kept in view and crane round to keep it in sight. When choosing an approach, a conventional circuit, with a normal downwind leg may not be best to a pinnacle or a ridge. Consider flying up the downwind slope, downwind-ish, being carried up by lifting air and turning into wind for the landing site. Avoid the lee side of the slope, if possible, as this has down currents.

A steep approach from the lee side of the landing site avoids more of the falling air than a shallow approach.

Make sure that there's a way out to go around if necessary, which should need no more than a gentle peel-off.

Once landed, pump the cyclic up and down to settle the skids into snow. And don’t park on the downhill bit - try to keep the engine over the highpoint of a knoll to avoid the aircraft going skiing – with or without you!

On completing a go-around for an aborted approach, ensure you have positive VSI before turning downwind, to avoid the combination of a falling aircraft and rising ground…

When you're trying to work out the wind direction from grass tussocks, typically on the recce, look at a tussock for a moment or two and if it doesn't give you the answer, look at another instead. It seems obvious to me now, but wasn't until I was told!

When departing, don’t leave the security of your spot until E+R are at the top of the green (not drooping) and you have a significant, satisfactory rate of climb. Then accelerate forward – into wind – for a max rate of climb and get a good A/S before turning. Beware of overpitching - pulling more collective than there is power: The E+R will droop before the Low RPM horn (or GPW horn) sounds.

The sloping ground in the mountains is not only deceptive for AS, as I discovered approaching an ag strip in a sloping valley. Despite thinking I had a good approach angle, I found I had been well below the site elevation, having been deceived by the inclined strip.

Cross ridges at an angle, to allow a way out with a gentle turn if necessary.

In turbulence - reduce speed and power immediately.

One interesting sloping ground difference from my UK training was landing only the skid tips for very sloping ground passenger dis/embarcation.

Mountains, certainly in the South Island of NZ, but probably everywhere, are far more attractive places to fly in than the flatlands of East Anglia, not just for the flying, but for the scenery, which I can't do justice to. The weather seemed more reliable than UK weather too, particularly considering it was winter.

Watching the Robinson Safety Video, I finally grasped mast bumping, which was an improvement on my previous rather tenuous hold. I haven't seen the video in the UK, nor had my UK instructors.

The greatest difference between the UK & NZ PPL(H) syllabi is the compulsory mountain training in NZ. Another is slingloading, a Kiwi PPL option, which isn't permitted on a UK PPL. By the time I'd flown on five consecutive days, I'd covered the mountain training component of the PPL(H) and after a little revision, some low flying (from which I guess that nap-of-the-earth flying may be the most fun to be had with trousers on), another exam paper, a Biannual Flight Review (the Kiwi equivalent of the Licence Proficiency Check) and a remarkably small a mount of money, I found myself with a Kiwi PPL.

Did I like it all? Enough to have just found my way back to NZ.

FAD

[[email protected]]

Flyanothertday, if you want to fly safe in the mountains then make sure you have an artificial horizon or attitude indicator and constantly refer to your flight instruments. Just relying on the ASI is insufficent - attitude determines your airspeed so that is what you should rely on. It is very strange referring to instruments when you are flying up a valley or into a bowl but if you want to avoid climbing as you enter and descending as you exit then it is what you must do.
A top technique is to set straight and lever power for the speed you want to fly at (typically 40 - 60 kts) and pick a feature on the ground (rock, tussock etc but don't use sheep!) that is approximately in the place in the windscreen that the horizon would be (about a third of the way up above the coaming on Lynx/Sea King). Then fly at the feature keeping it in the same place in the windscreen and check the VSI - if you are climbing then pick another rock further down - if you are descending then pick one higher.
Once practised at this technique you will be able to fly in to valleys and bowls without climbing and make a level turn at the end which significantly aids the subsequent approach to the LS.
As far as advanced mountain techniques go eg in stronger winds then make your approaches using the updraughting side of the featurein a curving flightpath so you never get on the downwind side of the ridge/pinnacle etc - your escape route is therefore always into wind and into updraughting air.

[chopperchav]

Would love to do a mountain flying course in the Alps(Swiss look quite nice). Anyone know a company which runs courses?

[tecpilot]

You can go to nearly any company but not to REGA or other officialrescue operators. Take the course on a ship you have current. You can have all common single and twin types. But be prepared to really expensive hours!

[jellycopter]

Chopperchav,

Are you in the HCGB? If so, take a peak at the most recent issue of RotorTalk re mountain flying. You can get valuable experience through the Club and very close to home.

J

[Heliport]

Threads merged.

Separate thread: Technique and experience for mountain rescue

[inthegreen]

Mountain Approach procedures

Just throwing a topic out to the group for discussion. Every pilot flies a little bit differently, with respect to their training, their experience, the diversity of their missions and the amount of exposure they've had to more experienced pilots.

I'm interested in what procedures other pilots use when conducting mountain approaches. I have my own procedures, which are not unusual or unique in any way, but there are many ways to accomplish the same feat. If you feel like responding, give your procedure/s as well as your reasons for doing it that way.

Thanks

[paco]

Many schools teach the Okanagan-type shallow approach, which was used by someone many moons ago and never been questioned since.

It should (in theory, anyway) minimise collective movement for the hover, since your power is already applied, but there's very little margin up your sleeve at the end, and you need to be very aware of your winds, although it does give you a good idea of the level of your site. You are also trying to land at probably the only spot available for miles around, and if you have a problem in a shallow approach, you aren't going to get there.

I generally turn in steep around 60 kts with the disc loaded as much as possible, consistent with descending at about 250 fpm (landing site just forward of the nose). If the blades have some tension on them, they are less likely to be overstressed, and the controls are more responsive. Coming in steeper also means you use less collective and allows you some momentum from gravity if you need to peel away in a hurry, giving you half a a chance of making the site. Certainly more than with a shallow approach.

Also, don't approach straight in to a site, that is with a large lump of mountain directly in front of you - 45 degrees is best so you can peel away. Mountain pilots always have a way out, even after they've lamded!

Phil

[Arm out the window]

Same as paco, I like a steepish approach, but slow with power on so there isn't a big embarrassing suck at the end.
Also keeps you up out of the possible turbulent downdrafts on the lee of the hill.

Approaching along a ridge is a good idea rather than over the valley between two ridges, because if you have to turn away you can just 'fall' off the side of the high ground - obviously a good escape route is a must.

I was also taught, and like to use, a 'gunsight' technique - ie from the start point of your final approach, sight over the crest (if possible) and pick a point on the far valley floor that you can line it up on, like a gunsight. If you keep the two points superimposed, you will be flying down a constant angle.

Lack of horizon can be a problem, so you kind of have to work backwards and check your airspeed vs. ROD. vs. power (and cross check on the AI if you've got one) to ensure you're not getting sucked into some weirdly steep or shallow approach by the optical illusions possible with hills around.

That's a few that I use, anyhow.

[rotorboy]

Steep! Aye Carumba....
Shallow, Shallow, Shallow, power in way early, minimize collective movment, always have an out.

I like a low recon, feel the winds, pick my route, often downridege, down slope ( though nothing wrong with upslope if done correctly - ALWAYS have an out and power available.

Steep may work up to <5'-6'K but is a shure way to get killed in a hurry above 6-7k. Strong, GUSTY mtn winds (20+) make holding a steep angle often unsafe and too risky

Always cross ridges at a 45 angle.
Dont be afraid to say no.

Above 10K I often go super light first time in (espically in the summer). Ridge winds are often super light and viarble. IMO those are the most dangerous.

Other good rule I go by if I cant get into a spot after two try's, I look for a new one.

There are times in the B2 astar I am one at a time to 13+.... I have seen too many DA deaths due to heavy a/c and steep aproaches.. up high here in the SW rockies , you can stall a rotorsystem in a hurry. It gets too hot and too high.
My attitude has always been saftey and being conservative from the get go. after you get a feel, you can push a littlle harder. If you do like it, call my boss ( he'll back me up)...

ok off my soap box back to my beer
rb

[[email protected]]

I think the only reason for doing a steep approach is to keep above the demarcation line (where the laminar flow over the mountain feature turns turbulent) but I would always go for a shallow or even level, curving if required, approach staying in the updraughting air. You use less power and have a safe escape route if you don't like it. Oh and do a power check at altitude before you commit to the site just in case the engine(s) don't produce what they should.

[oldbeefer]

For a strong wind day, the French (working in the Alps up to 12000ft) would generally fly a climbing approach obliquely up the upwind side of the hill (having done a recce first from a safe ht above the LS) and then almost spot turn into wind as they came over the LS. This was in an underpowered Alouette II, and it worked a treat! Meant an option to fly back into the valley, on the updraughting side, was almost always available if turbulence or power became a problem.

[NickLappos]

Shallow! Absolutely! Make the approach slow, shallow and with no big power pulls at the bottom. Test max power before you start the approach, and note the torque MP that you have. As you decelerate on the approach, you will naturally bring the power in, so watch the power carefully, and if you get close to limits just nose down a bit and fly away (it is easier to fly away from a shallow approach than a steep one, PACO!) NEVER commit to the hover if therer is insufficient power.

The worst problem in an altitude landing is arresting the descent with the last bit of power at the bottom. If you are steep, you have a higher rate of descent and a bigger need to suck in power at the end - both factors help you fall through and hit hard if you misjudge (in fact, you will then call it Vortex Ring State, so that you are not at fault, Nature was!)

The only time to be steep is if you need to be for some other reason on the approach, such as obstructions.
Land crosswise to the wind, never from the downwind side. Often 45 degrees to the ridgeline works well.

[paco]

Sorry, not shallow for me, although it is a tool in the armoury for those once in a lifetime occasions. Collective higher, further to dump it.......

Not only that, you should be flying into the site, not hovertaxying

250 fpm in a jetbox uses about the same power as that required to hover (assuming ground effect is available) so there's minimal collective movement anyway.

phil

[NickLappos]

250 fpm at 50 knots is 3 degrees of descent, at 25 knots its 6 degrees, both on the shallow end of approach steepness......

[170']

En-route, try to find the overlying wind, then imagine the wind as water flowing over the mountain from that direction, try to imagine what’s actually happening

Fly recon and check wires, pylons, road or tracks…etc… if it’s wide open, I go straight into a low pass in the direction I think will be downwind…Pass level with the LZ at eye level, 50KIAS (stabilized) …

Check torque and altimeter at level of LZ (remember both), general feel, (a/c feels buoyant, stable, or feels skittish, if you guessed right on the downwind, you should be skittish, heading, airspeed etc)…glance sideways and get the sense of groundspeed

If you keep in tight with the hill, and maintain a light pressure on the pedals.
Any down-flow will cause the machine to want to weathercock into the hill.
Up-flow will cause you to weathercock away from the hill. …

Once passed the LZ, having checked the 5 S’ and no further info available.

Go for 60 KIAS and climb 50’ …once level at 50’ above LZ.. Give yourself whatever you want as a final approach distance, then turning away from the hill, make a 180 and set up on final with an option for a go-around….

As you turn away from the hill, don’t get higher than 50’ above LZ elevation. Continue inbound to the LZ maintaining a drop-off down slope in case you get any problems.

At no point in this type of approach will you climb more than 50’ above LZ elevation. When inbound, stay in tight following side hill, not flying into the hill...


Once you get inbound, reduce speed to the same speed you passed the LZ on your initial pass (on LZ elevation) at this same speed (stabilized) check torque…if you have less torque for same stabilized airspeed you’re in up-flow/upwind and right where you want to be. Think up-flow, down-flow. As well as upwind/downwind

As you get on short final, check visual groundspeed again out the side window, check torque…you should have less torque, feel buoyant, GS will be less. You have a loaded disk as you didn’t need much of a descent…fly it onto the LZ. …Make sure you don’t stop short, but fly it to the LZ…most of the power is already in and not much more to do…

Keeping in mind I don’t want a TR strike, I try to keep the machine kicked out a little, pointing along or down slope, in case it all gets funky in the last little bit…Any problem and I peel off down slope going for airspeed…

Not my procedure, learned it a long time ago in a Mtn flying course…

I don’t claim it’s the best or quickest, but if you’re on the limits with weight and power, it’s a really good way to put the odds on your side…

I don’t think much about it anymore, second nature now, but it’s worked in some real high elevation regions, and I’ve never once had to use my superior flying skill

170

ps, this is the procedure I use in real mountains, low hills is a different deal

[paco]

I don't do 60 knots all the way down - I think I said I start there. By the time I get to the spot it's all very gentle.......


Phil

[Arm out the window]

Yep, same here. Slow, steady, with power early.