Short/Rough Field techniques.

[sennadog]

I'm planning a holiday to RSA in the Spring and I'm after some tips that hopefully I can practice in the UK for landing on shorter strips that will inevitably be rougher than those I've encountered in the UK so far. Also, some of the strips will be at altitude so and information and tips for these will also be welcome and as a gudeline I'll be flying a C-172 of some type.

Also, does anyone know of any strips in the SE of England that I might be able to use for practice? Obviously, I'm going to take a course over there before setting off on my own but I'd like to get ahead of the game in the UK first.

Cheers all.

:D

[BlueRobin]

Clacton - 600m of grass. A 172 operates out of there. Should give you an idea of performance.

[Bluebeard2]

Not really SE, but Leicester might be worth a try as it has a number of short runways (sub-500m) both grass and tarmac in a variety of directions, and its always struck me as being relatively quiet.

An alternative is to find a nice big runway and mark out a suitably short strip, either by pacing it out or by reference to other features. This will allow you to screw up without REALLY screwing up :eek: For a bit of fun I always try to make the first turn off at Elstree on Rwy26 when 1 up in a C150, guess that's probably about 250m :D

BB

[QDMQDMQDM]

Two thoughts:

1. re: Density altitude, all the usual caveats apply, but I'd add be careful in gusty conditions and with mountainous terrain around the airfield or else trees etc which can affect the microclimate. One thing in particular to watch out for is rivers on the take-off / approach which can be quite cold and cause turbulence or downdrafts just when you don't want them.

2. For most purposes, rough field technique in a nose wheel can be confined to keeping the weight off the nosewheel as much as poss with up elevator. On occasions where it's really rough and you want to get off really quick, you can use full flap. The technique I was taught in Idaho in a 172 is start with one notch and as the speed climbs drop full flap and count to three to allow for the slow electric descent of the flaps, then pop the column back slightly to get off the ground in ground effect and then keep the nose down, bleeding off flap to one stage while in ground effect and then accelerating and climbing away.

This works a treat in the Super Cub where you can just pull full flap in an instant, then bleed it off more slowly in ground effect, trading lift for speed, like a cyclic control or collective or whatever it is they have in helicopters. It does work too in an aircraft with electric flaps, like the C172, but it's not quite so intuitive.

QDM

[FlyingForFun]

Senna,

I've never done any real short/rough strip work (unless you count the runways at White Waltham as rough!). But the general idea is that, for take-off, follow the technique in the POH. This will usually involve full back elevator during the take-off roll, and lowering the nose as soon as airbourne in order to gain speed and avoid the stall. Landing will usually be slower than normal, sometimes on the back side of the power curve, involving lots of power to couteract the drag, and a flatter approach than you're used to. But the POH will take precendence over everything I've said - I've never flown a C172, so I make no guarantees that the technique I've described is appropriate.

You should have covered all this for your PPL - if not, read the POH, and get an instructor to run through it with you in the air. I doubt that practicing over here will prepare you for the real thing (it certainly didn't prepare me for the one rough field I've flown into), but at least you'll know what to do, even if not what to expect.

Altitude flying is something I do know about, having spent 100 hours or so flying around the moutains in Arizona.

Take-off and landing really shouldn't be a problem, so long as you do your performance checks. If you're flying a type such as a C172 you should find you have performance graphs in the POH - use them for every flight into conditions you're not used (that includes any combination of weights/altitudes/temps/winds you're not used) and you'll be fine. It will take longer to accelerate on take-off, don't be tempted to rotate too soon. And both the take-off and landing will be at a higher ground-speed than you're used to - trust your ASI and fly the attitude, ignore what your brain tells you about your speed.

(If you're flying an aircraft without performance graphs, as I was, there are two techniques you can use for guestimating the performance. First, look at the graphs for a different type, and apply similar percentage increases for similar differences. Second, and probably more importantly, talk to the locals!)

In the cruise, you'll need more throttle to get the same amount of power at higher altitudes. As the air gets thinner, you need a greater volume of air to get the same mass of air. If you don't open the throttle, you'll notice the RPM dropping off. Unfortunately, just increasing the throttle to maintain RPM doesn't quite work - the thinner air provides less resistance to the prop, so in order to set the same amount of power as you had at lower levels, you'll actually need a higher RPM at higher levels, and therefore an even greater increase in throttle setting than you would to just maintain RPM.

As a guide, I used to start opening the throttle at about 4000'. By about 7000' I was at full throttle - any further increase in altitude and I would have to accept a decrease in power.

(It's no problem if you have a constant speed prop - you can set the power on the manifold pressure guage, and the prop will coarsen as necessary. You'll still run out of throttle at about 7000', but you'll be able to set it much more accurately below this.)

Leaning also becomes more important. Always lean in the cruise. You'll need to get some guidelines from the instructors as to whether to lean for take-off, I was told to lean the Super Cub for take-off, but not the Warrior or Arrow, and that seemed to work for me.

Also, the difference between IAS and TAS starts becoming more relevant at these altitudes - if you don't convert IAS to TAS when doing flight planning normally, you might like to start, otherwise you'll find that you're consistently faster than expected on your ded reckoning.

Far more important is the effect of winds blowing over mountains. The general rules are: 1) Never fly close to mountains on the down-wind side - the down-draughts can make the aircraft uncontrollable, and 2) Always make sure you've got enough space between you and the mountain to do a 180-degree turn and get out.

I should probably emphasise the importance of understanding these winds a bit more: take-off and landing performance is easy to do properly, and unlikely to kill you. Not understanding how the engine and prop behave at altitude might mess up your navigation a bit, but won't kill you. Failing to understand the winds will kill you if you get it wrong on a windy day. Always be aware of where the wind is from, how it's going to be affected by the terrain, and how to get out of trouble if you've got the winds wrong.

I'm sure you'll have a great time there - I'd like to get out there myself some time. Make sure we get a full report!

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

[Fly Stimulator]

sennadog,

You should be able to do both those things without leaving home base.

Missing the runway and landing on the grass to the north of 08/26 up by the G holds should do the trick! ;)

[foghorn]

Good stuff here.

One thing that you will come across in SA that you rarely get here is gravel strips. You must never come to a halt on a gravel airfield with the engine at any higher power setting more than the POH stationary setting (usually 1,000 - 1,200rpm or whatever the book says). Anything else and you will get multiple prop chips (even with the aircraft stood on gravel at the stationary RPM, from outside you can hear the odd 'ping'). Use the absolute minimum power possible to pull away from stationary - you can increase it once you're rolling - some finesse is required for this.

Run ups are done whilst rolling on the taxy-out unless you are lucky and the strip has a concrete run up pan that is kept well clear of Gravel.

As for high density altitude strips, you have to consider leaning on the ground at full throttle to the rich side of the peak rpm, or else you often don't get anything like full power. On a high-altitude gravel strip you have to do this on the roll during the taxy-out as well - not an easy thing to do. This is even more important when heading up into the highveld in an aircraft usually based near the coast.

As ever, the POH overrides my club bar chat here - and local instructors will know the normal procedures for their club aircraft...

Other than that enjoy it, SA is a fabulous, cheap and friendly flying environment, and closer to UK practice than the US (standard overhead joins.. yippee)

cheers!
foggy.

[sennadog]

Some good stuff here. Keep it coming. Obviously I can practice at my local airfield but there's nothing like a genuinely short RWY to focus the mind.....:D

[Chimbu chuckles]

First realise there is a difference in technique when you are talking short field or soft/rough field ops.

The potential traps for inexperienced players in a situation combining short rough strips and high density altitudes are myriad..plenty of bush pilots with thousands of hours come unglued.

Short Field Ops;

Popping full flaps is NOT a good idea. Full flaps is characterised in most aircraft as being a lot more drag than lift...at high DAs/weights you may well find that this 'technique' simply stops all acceleration and leads to a little bunny hop followed by an overrun of the available strip length.

In every Cessna I've flown on bush ops (C180/182/185/206/210) flaps 20 was optimal...leave it at that.

If there are no obstacles in the takeoff splay simply ensure that the performance of the aircraft is adequate via the graphs and go. Bare in mind that if DA is a consideration you should have done a takeoff limitations check for typical conditions, say ISA +20, nil wind and at the realistic weight you will be at (or MTOW) and already know you can get out again before you even land there.

If a strip is just short set flaps 10 or 20, accelerate normally and a few knots(about 5) before TOSS gently raise the nose and let the aircraft fly off when it's ready. Dragging the nose off early will increase induced and form drag and lengthen your takeoff roll. If there are no obstacles let the aircraft accelerate in a very shallow climb to a higher speed to give you a buffer for windsheer and retract the flaps as you go...but not too soon...50' minimum.

As someone else posted bodies of water right at the end of the strip such as rivers or lakes or even a swamp do lead to areas of sink because they are colder than surrounding terrain. Having that buffer of extra speed will take care of it. Terrain, even very small hills or rock outcrops close to and upwind of the strip must be taken into account as well. Air is a fluid the same as water...think of air flowing around features as the same as water flowing over rocks etc in a swift flowing creek/river then you will be able to picture what the air is doing around the takeoff/approach flight path. Yet another reason NOT to pull the nose up and maintain some silly best angle of climb speed.

If a strip is VERY rough then you should NOT BE THERE...you will almost certainly be contravening your rental agreement. On a moderately bumpy strip simply enough back pressure on the controls to take the most of the weight off the nose wheel is enough...and that backpressure will be a reducing amount as the aircraft accelerates...remember the drag you are causing.

Landing on short fields, of the type we are talking about, requires no special technique beyond accurate airspeed control and touching down exactly where you should.

IAS exactly on 1.3 VS at full flaps to about 50' then gently reduce power to idle and touchdown at the first cone markers in from the threshold (about 30m usually) at Vref - 5 odd knots followed by reasonably heavy braking will have you stopped in 300 odd meters...if that's all you have you will be certainly leaving most everything behind when you leave...your bags, your wife/girlfriend etc. DO NOT be tempted to touchdown in the first 5 feet of available runway...it's dangerous and NOT REQUIRED!

IF you are overshooting your touchdown zone, between the first and second cone markers in from the threshold markers, then GO AROUND.

On the subject of GAs...full power and then instantly reduce flap to flaps 20..remember from flaps 20 to flaps 40 is almost all drag and very little lift...it will cause a huge pitch up moment that will require LOTS of forward pressure to counter act...get rid of that drag and pitch moment QUICKLY (no the aircraft won't stall...not even close IF you maintain Vref +)

Soft Fields.

It goes without saying that if you have a choice don't go there until it's dried off some...you won't have to wait long in the African heat for things to improve.

However if you have to land somewhere that might be soft the above technique remains the same EXCEPT don't jump on the brakes...gently feel for brake effectiveness and use all the LDA to bring the aircraft to a halt.

If overnight rains have reduced your strip to a muddy track your first option is to do NOTHING. Wait for the sun to dry it off.

If you have double the TODR for dry conditions, and you really want to leave, then this is what I used to do. Bare in mind I was bush flying for a living and we didn't wait for anything...but at 10 or 20 sectors a day we were current and practiced and knew our aircraft and the airstrips VERY WELL.

Drag is the big enemy on soft fields, you need to do EVERYTHING in your power to maximise acceleration.

Wheels cause drag, especially the little one at the front, flaps cause drag (initially).

So in a Cessna I would set flaps 10, max power and stick back to keep the weight off the nosewheel. When the aircraft is getting light on the wheels, nosewheel will be just off the ground, select flaps 20, manual flaps are better but electrics work too. The aircraft will 'pop' into the air at a very slow airspeed so let it accelerate...when you are SURE the aircraft will stay in the air retract the gear if it's a that kind of gear. Then as per short field above...accelerate further retracting flaps incrementally at a safe height and with good margins of IAS, say above 30' to 50'.

A note about retractable gear...mud and crap can cause problems with the gear micro switches on 210s and C182RGs...particular attention to them on your daily and keeping them clean will save you embarassment.

Relatively few airstrips that are 'short' also have significant obstacles close in, if there are be VERY carefull. Perhaps even explore the option of accepting some tailwind for takeoff if the other way has no obstacles. Stay within POH limits and make damn certain you have enough TODA with the maximum tailwind you will expect to experience on that takeoff.

Walking around the strip and studying the wind and surface conditions (check for soft spots) etc is a very good idea...use the peak gust for calculations and then try and time your takeoff roll to occur in a lull.

If operating significantly above sea level make very certain you understand leaning for best power on takeoff...about 100F ROP. Generally only an issue above say 3000' DA. Notice I said DA, Density Altitude not elevation....make sure you understand the difference at temps around ISA + 20 or 30 degrees C.

Discussing various strips with local bush pilots is an absolute MUST! Even experienced bush pilots do that all the time.

I used to drag fully loaded Islanders out of flat strips of 380 mtrs at DAs of many thousands of feet....fully loaded 402s out of 650 mtrs at sea level.

600 meters in a Cessna is not a problem if you are carefull and follow the above. get an instructor and go find a 500 or 600 meter strip and practice...go arounds especially.

Have a great trip:D

Chuck.

[Aerobatic Flyer]

What can one add after Chimbu Chuckles' excellent post?

Flying in and out of short, rough, high strips in the mountains, there are 2 points which were impressed on me which could come in useful:

1. Have a plan for what you're going to do if you mess up your approach BEFORE you start the approach. As Chimbu Chuckles says, no special techniques are required other than speed control and an accurate touchdown point. If you miss your touchdown point on a short strip with high density altitude, can you go around safely? If not, which direction should you steer after touchdown for the least unpleasant crash? If you touchdown halfway down a short strip, and then realise you're not going to make it you'll probably hit whatever is at the end of the runway. There might have been something much nicer to hit to the left or right!:rolleyes:

2. On a short field takeoff, one thing which goes without saying is USE ALL OF THE STRIP. People often don't.

In SE England, there used to be an excellent short strip near to Canterbury (close to the village of Boughton, in between Faversham and Canterbury), but I'm not sure if it is still open. It had an obstructed circuit (hills), a bit of a slope to the first part of the runway followed by a level section and a broken tarmac / gravel surface. If it is still open it's most definitely not somewhere to go and discover solo. I think it may have been closed down, though. The M2 motorway is in a cutting at the end of the runway, and more than 1 pilot has ended up on the road, usually after taking off uphill, getting airborne in ground effect on the level section, then stalling over the road as the ground falls away...

Have fun in SA. Watch out for the poisonous spiders!

[Saab Dastard]

Sennadog,

Probably grandma and eggs, but an instructor made a good point that for short field landings one should keep a safe speed on until after the turn onto final, then start flying on the back of the drag curve.

SD

[QDMQDMQDM]

Interesting piece on STOL techniques in the Super Cub which is nevertheless generally relevant:

http://www.supercub.org/phpBB2/viewtopic.php?t=248

One of the most noteworthy things about performance discussions in general on the forums at supercub.org is the way they always tend to get back to weight and how a Super Cub at gross is a very different machine to one lightly loaded. These fellows are simply obsessed with weight and its effect on performance!

I think there is a tendency amongst pilots to discount this difference and to presume that just because an aircraft is within weight and balance limits it can be flown with impunity. It's not just take-off and landing distances which change, but the way it handles, the responsiveness to power and, most critically of all, the stall speed.

It seems safest and smartest to consider that a lightly loaded aircraft and one at gross are two completely different machines in many different ways.

QDM

[Chimbu chuckles]

Sennadog that's a good way to end up crashed short of the threshold...particularly in high DA situations. You can too easily end up in a situation where you have full power on and no matter what else you do your ROD will increase dramatically....I've seen it happen more than once...luckily not usually fatal.

Simple accurate flying is all that is required!

Be VERY WARY of information that comes from the mouths of (young) instructors...on subjects other than the pilot licence curriculum (and even that sometimes:rolleyes: ) as they tend to have no experience on the subject and are only regurgitating bar talk from someone else who has, probably, little or no experience.

The similarities between Flying Schools and the real world ends at aeroplanes parked outside!

Chuck.

[alphaalpha]

Sennadog:
Only one thing to add to the above excellent posts --

You said you would be flying at altitude. Are you planning to go into any mountain strips (steep slope, one way --land uphill, take off downhill-- maybe with no go-around capability after short final due to terrain). If so, remember these strips are killers to the unwary.

I did a bit of flying into such strips in the Alps (with a mountain instructor). Typically ten landings at each are required to qualify as well as much study and experience of mountain flying generally. The advice I had after my intro was not repeat not to go and do it by myself until signed off. That said, it was brilliant fun and I would reccommend it, but with a suitable instructor.

One final point, the PFA do a strip-flying course as part of their coaching scheme.

Enjoy....

[Genghis the Engineer]

Try the microlight strip at Middle Stoke, on the Isle of Grain (more or less due S of Southend). Best phone them (01634-270780) but it's short, bent, with high obstructions - also cheap, friendly, and does a good bacon sarnie at lunchtimes.

Details are in the RAF guide and Lockyears, but not Pooleys.

G

[Fly Stimulator]

Yes, Stoke is fun isn't it?

Here's a picture of it so everyone can play "Spot the Airfield"!

http://www.theflyingschool.co.uk/gallery/stokewide.jpg

[Chimbu chuckles]

Between the road and the water/mud mid piccy?

Here 's one of my all time fav spots:D

Kamalai (http://www.fototime.com/{382993DE-DD67-4582-A822-EB665857D531}/picture.JPG)

Kamalai Finals (http://www.fototime.com/{4B33F0AA-2416-42E2-B381-89E5076A76E3}/picture.JPG)

Kamalai takeoff (http://www.fototime.com/{BBC643BA-BC97-41FA-8C5D-C35833067C08}/picture.JPG)

Sennadog...as per alpha's post do not be tempted to try strips like this one...the 1st piccy was taken the day I was there retrieving bits of a crashed Islander...although the pilot survived...the other two were taken by a mate and give the whole picture of this gem. Elev 5000' (DA 9000'+) 13% slope, 400 meters from memory:D

Chuck.

[knobbygb]

I would have said top left, near the white line feature, but Ghengis says it's 'bent'. How about bottom left, just to the left of the road. Curved feature partly on grass and partly soil?

[Chimbu chuckles]

Credit for this piccy goes to Herc Jerc.

This is another of my 'fav' spots...virtually directly under the Islander in this pic is the wreckage of another Islander that suffered a L/H prop hub failure as he was getting airborne...he was a top bloke and newly married....I'm still friends with his widow.

Kanobea departure (http://www.fototime.com/{06997C29-EDA8-4691-A099-3BB0B20E6680}/picture.JPG)

Need any more convincing to stay away from one way strips in the hills Sennadog?

I'm not sure who to credit this piccy to however while it is in PNG it is probably very representative of a 'worse case' strip that you might face solo in Africa...from piccies I've seen of typical African bush strips anyway. It's 580 meters and 2400' AMSL...at ISA + 20 that probably equates to 5000' DA (without doing the sums:D)

Mt Bosavi (http://www.fototime.com/{004C3273-9A2C-406E-9CE5-72C88FC86715}/picture.JPG)

I don't want to scare you off having a fun trip...and by all means have a go at some real hard strips under supervision if you can organise such...but much more difficult than something like Mt Bosavi should be left to the pros my friend.

Chuck.

PS Have a look at the little gentle hills surrounding this strip and imagine what say 10 kts of wind blowing over them will do to your approach and particularly to your climb performance in a loaded C172 on a hot day:eek:

Imagine it wet and boggy in patches.

If you approach this adventure with brain engaged you'll have a ball and be a much better pilot after....best of British:D

[Final 3 Greens]

Senna

Try Lashenden aka Headcorn.

Not short, but rough as sin!

[steamchicken]

hmmmm.......immediately top-left of the village, poss. grass strip? oops, that's too straight! bottom left in the curve of the road, I'd say.

[FlyingForFun]

I think it's near the top-left of the picture.... from the village, follow the road up and to the left, and there's a green/brown field to the right of the road. Looks like there's a runway in the field, with a definite dog-leg in it.

So, do we get to find out???

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

[Edit - Genghis said the strip has "high obstructions". Can't see too many of them on the area I've identified, so I think I'm wrong. Now I'm really curious!]

[Aerobatic Flyer]

A favourite spot to compare with Chuck's. It's a little spot called La Croix Rozier in the Beaujolais region of France. It's about 250m long, with an initial slope of 26 degrees, then a slightly more level section, then a steep slope again before the top platform.

Here are some photos. (http://groups.msn.com/someflyingpictures/shoebox.msnw?Page=1)

You aim at the trees, and start the round out you're about 50ft agl. If you get it right, the ground comes up to meet the wheels just as you reach Vs!

On take off, the trees at the end look very close sometimes....

Ideally you'd want a 10kt tailwind for landing - the slope will stop you even if you land long, and the wind will help you take off.

Sorry about the quality - it was a murky day, and I think I had the camera set to low resolution....

(Edited due to technical incompetence at posting links....)

[skyraider]

Sennadog,

most of the bush strips I have seen in SA look similar to the piccy of Mt Bosavi that Chimbu posted.

One thing to bear in mind is that a fair number of them are cut out of the middle of timber plantions and the challenge for lowtime pilots is mainly to fly the approach... short fields are not too common because space is not a problem and the terrain is often very accomodating. The challenge is a field that is surrounded by 50-60 foot gum tree plantations, even in light winds...

Most of the fields I have used in the UK are shorter than most that I have used in SA.

Density Altitude and location have been more of a challenge.

Sky

P.S. got space in your case...

[QDMQDMQDM]

you can never have too much fuel... unless you're on fire...

...or trying to get out of a strip that's ju-u-ust a tad too short.
;)

QDM

[skyraider]

you make a good point.....:D :D :D

BTW... the airfield at stoke is the one with the windsock in it.... can't believe you guys didn't spot that...;) :D

Sky

[sennadog]

Some really solid adivce here - cheers peeps.

A bit of background first....

Firstly, what I meant as "Rough strips" is that they look rough to me in the pictures that I've seen compared to the normal grass ones that I land on.

Secondly, as I obviously haven't repeated myself enough times, I am Captain Cautious and as an example, if I have the choice between a Bush strip that is 700m and one 30 miles away that is 1000m then I'm going for the longer strip. This holiday is about improving my flying, getting experience and seeing what looks to be a fantastic country. In other words, my b*lls are fine - I'm not out to prove that they are made of steel!

:D

Chimbu chuckles - I wouldn't even think about trying to land at one of those strips, let alone even attempt it at this stage although I hope that one day I'll be good enough to have a stab with a local onboard.

The chap I'm renting from insists that you take a two hour course/check ride and I'm insisting on 4 hours minimum so I hope this puts it into perspective what I'm all about. As I do when sailing, I normally collar the nearest salty old sea dog, buy him a beer and get the inside gen and I'll do the same over there.

As I've been told, most flights in this area are of about 2 hours duration as the most I've done so far is 1 hour I need to get more air time (I sound like a mobile phone salesman here;) ) amongst other things.

Anyway, minor rant over.:p

There is some good stuff on here. Stoke looks worth a look as it's not too far from here and is the kind of thing I'm after. As I said before it's easy to do a short(ish) field landing when you've got 700m to play with but the real thing has got to be better.

Cheers All.

:D

[Fly Stimulator]

Stoke - the answer

The runway at Stoke is highlighted this time.

The curved feature across the centre of the picture is a railway. What you can't see in this view are the high-voltage power lines and pylons which run next to the railway and right along the edge of the strip, just to keep things interesting!

http://www.theflyingschool.co.uk/gallery/stokewide2.jpg

[Chimbu chuckles]

Sennadog,

Good lad...I wasn't trying to lecture you however many pilots do try really dumb things and I was a little worried you might head off into the veld and attempt something too far beyond your experience...stretching yourself is a good thing, provided it's incremental:D

Steep strips are not hard of themselves Senna, 10 or so 'circuits' at Kamalai and you would, probably, have it (reasonably) down pat. The slope gives you a fair bit of leeway for little 'imperfections' in technique as long as you don't end up low...that can be a killer....windsheer can make them a little more sporting but on a calm morning they are just good fun. Kanobea is flat but the terrain(and strong winds at certain times of the year) was the killer...from memory there were 4 wrecks at Kanobea one of which was a Tubine Porter.

Can't work out why spotting Stoke was so hard...look in the middle of most peeps piccies and you see the subject:rolleyes: ;) .

Aerobatic Flyer,

That little spot looks like a hoot.:D

The rule of thumb we used for steep strips in PNG was, < 5% Vref, 5 to 10% Vref + 5kts, > 10% Vref + 10kts...power stayed on till you were in the landing attitude, came off a bit for touchdown then straight back on again to get you to the top.

17% average is as steep as I've ever experienced but the steeper the better as far as I'm concerned. At 25% 250m is probably the equivalent of 750m+ flat...except you couldn't stop from more than about 15kts on takeoff on that slope:(:D

Final approach was always flown exactly as you would to any flat runway, ie 3%, except you obviously must 'look' very high going into a steep runway. We had a bunch in PNG where the first 60 or 90 meters was down at 5% followed by 17 to 20% up for the final 300 meters giving an overall gradient of about 13 or 15%, which was how gradients were calculated there, average between each end.

Clearly you had to 'look' low going into these but as soon as you crossed the threshold you would look high, touchdown on the downslope and POWER up the hill...usually through a big muddy hole at the bottom....just all sorts of fun:D

Chuck.

PS Here's a piccy of short finals at Kanobea( elev 4000') taken by Pinky the Pilot from the RHS of an Islander, presumably taken while he was on area famil before being checked in there himself. It's taken from just past the closer ridgeline...looks innocuous enough until you try it when there is 15kts of quartering tailwind from the left...power would often go from takeoff pwr to idle to takeoff pwr and back to idle again in 30 seconds of final approach. Bad enough in an Islander with instant throttle response but far more sporting in a -200 Otter with PT6-20s that had 8 seconds of spool up time between stabilised idle and any meaningfull thrust:eek: That lends new meaning to anticipation...some days you gave it away on right base and flew home because there just wasn't enough travel in the throttles:D

Takeoff was a hoot in those conditions as well:(

Kanobea Approach (http://www.fototime.com/{3C54AB23-9FD6-415D-8745-25B2CFEBA20B}/picture.JPG)

[sennadog]

Chimbu chuckles. No worries mate. You put it a much better way than I did. Incremental stretching is what I'm after to gain experience.



Fly Stimulator. I take it you've landed at Middle Stoke? I've had a quick chat with a guy there who tells me that they've had a Warrior and 172 in there so it should be feasible with a Katana to begin with. As it's not far from here, I won't need much fuel and Rochester and Southend are close by for a diversion if required.

I need to get a copy of AFE as it's not in Pooleys.

What is the microlight frequency? Apparently, they use this frequency and I'm not sure how it differs from the RT I'm used to?

For information. The airfield number is: 01634 270236.

[Aerobatic Flyer]

Chuck,

The rule of thumb I use is a little different from your's. Approach is at 1.3Vs for slopes up to 10%, then - in theory - you add 1km/h (French aeroplanes.....) per % after that. Obviously things aren't as precise as that in real life, but you get the idea. So for a 25% slope, I'd be looking for an approach 15km/h faster than normal. For some short strips with a level touchdown point, a slightly slower approach is sometimes used if conditions are calm.

Power is kept on somtimes until contact is made, especially when using skis in the winter, then reduced momentarily to ensure you're firmly down before adding power again to climb the slope.

The wind and thermals can often conspire to mess things up nicely, though! This strip (http://www.pilotlist.org/montagne/images/larosiere_vuepiste.jpg) (also here (http://www.pilotlist.org/montagne/images/larosiere_atterrissage.jpg) ) is a case in point. It's 320m long, 10m wide with a 17% slope (concave then convex) at 6300ft altitude. In a headwind or crosswind from the right, the approach is flown in a descending airflow, which in summer is punctuated by vigorous thermals coming off rocks that are exposed to the sun. The density altitude is high if it's hot, and an on/off button would sometimes be more use than a throttle lever!

I'm afraid of breaking things (especially myself!) so I don't go there alone except when things are nice and calm!:)

Kanobea looks entertaining. I imagine with all those ridges the approach is a bit bumpy whatever the wind direction...? From the photo, it looks at least that you have an escape route to the right.

You also have a nice juicy variety of tropical bug that must help you to fix the aiming point! Do they bite?:confused:

[Fly Stimulator]

sennadog,

Yes, I've been in there, but it was in one of the orange Shadows from the unfashionable corner of Redhill. They will take off and land on a sixpence, so I didn't have to worry about the bend in the runway as I never had to get that far.

Having since moved on to metal aeroplanes as well, I'd say you'd be OK in a 172 or similar as long as the ground wasn't wet and you didn't take many friends or lots of fuel along with you.

I'd imagine a Katana would handle it easily, especially if it was just 1 POB.

The microlight common frequency is 129.825. Be prepared for exciting chat along the lines of -

"You there John?"
"Yes. Where are you Bob?".
"Behind you John."
"Where's Bert then?"


I'll be at Redhill both days this weekend, so send me a private message if you want to meet up to have a look at the AFE guide. I wouldn't mind having a look around your club, since a tailwheel conversion on the Cub looks appealing.

[nonradio]

Does anybody know what the slope at Nayland is?

[QNH 1013]

Nonradio, I flew into Nayland a few weeks ago. Afterwards, I walked the main runway and the following is just my estimate. Perhaps someone has the accurate surveyed figures?
I estimate the first 100m or so of r/w is fairly flat, followed by about a 100 foot rise in the next 200 m, (this is the bit you land on) followed by about 250 m of fairly flat ground past the hangers.
Again , this is only my estimate. Not difficult, and grass well kept and short.

I'm surprised no-one has mentioned Lundy Island. Very-rough surface with unyielding bits to avoid. You land across two fields passing through the gap in the stone wall. Unfortunately because of the curvature, you lose sight of the gap as you flare.

Plenty of nice short strips up in the Pennines. Watch out for the stone walls at the end !

[nonradio]

QNH, thanks - I make that about 1 in 6 or around 15%?

[Chimbu chuckles]

Aero Flyer,

That sounds a bit slow to me...but I suppose you're only lightly loaded...we were always at MTOW and occasionally a bit more:D

Chuck.

[QDMQDMQDM]

Went into a farmer's field today, not particularly short, 4-500 metres, ruts along it, much easier to land with the ruts, about 8 inches of quite thick grass / clover, no wind indication, but all went OK.

Got out fine too, two up with near full fuel and usual junk in the back, loads of room to spare, even with a slight uphill gradient (Super Cub 150 -- fantastic machine).

Came back 3 hours later... wind had definitely shifted, but hard to tell just what it was doing, looked more or less across the field according to a fire about 2 miles away, elected to land in the same direction, but came in too high, too fast, touched down long with quartering tailwind, stopped by the long grass and the slight up gradient with, well, enough room to spare, but not masses. Heart rate only 100, so things could have been worse, but I did have to go through the 'Is it going to land? Is it going to stop? If we do hit the hedge will it be a total write-off?' thought process. Not pleasant.

Two morals, totally obvious, but they were reinforced to me today and some might like to share them with me:

1. Don't try and rescue a crappy approach to an unfamiliar field in stressful circumstances. Go around.

2. If a go around isn't possible at that field and you're feeling a bit dodgy about it, don't go in in the first place!

We live (hopefully) and we learn. I'm still kicking myself for such idiocy, though. Pathetic.

QDM

[Philip Whiteman]

I must own up to weighing over fifteen stone. Add a passenger, cameras etc and I sometimes need more of our 450 m strip to get off the ground than I would like.

One measure—I hesitate to call it a technique—I have used is to charge onto the runway, opening up as I turn onto the centreline. Bad practice at a public aerodrome, I would suggest, but the idea is to start the take-off run with some kinetic energy in hand. I wonder if this ploy also avoids anything analogous to the helicopter ring vortex, which may occur when the propeller is running fast at zero groundspeed. (Helicopters lose lift when air recirculates through the rotor.)

Of course, my brilliant reasoning may be nothing but a heap of cack. Anybody able to confirm or counter these thoughts?

[QNH 1013]

PW, A useful technique but needs practice to turn with power in a taildragger and you have to be constantly assessing the wind. In addition to the kinetic energy gain you can sometimes get another gain because you are starting the take-off run with a higher prop efficiency. With some fixed-pitch props part of the prop will be stalled at max static rpm with the aircraft stationary. When this happens, the thrust will increase as the aircraft initially accelerates.

This technique also of necessity prevents you using every foot of the available distance because your radius of turn is larger at higher speed. It is therefore worth assessing if the shape of the field gives a better result by positioning the aircraft tail right back in the far corner of the field. On occasions I have not been too proud to get out of my aircraft and push the tail right back to the hedge. I like to have as big a margin as I can, in case something doesn't go to plan.

[sennadog]

Had a look at Stoke today and actually landed courtesy of Fly Stimulator who has this fantastic aircraft called a CT which is a kind of microlight with the 100hp Rotax.

It has very short take off and landing and is very quick with an amazing rate of climb - in other words a lot of fun. Thanks for that matey!

Back to Stoke....

It looks a bit out of my league for the moment in a 172 with power lines running adjacent to the strip and getting out again looks a bit difficult but someone suggested that Maypole might be a good idea and at 500m with what looks like a reasonable approach, I'll think I'll try there first.:D

[Fly Stimulator]

sennadog,

No problem - it was a pleasure. Flying back through those showers even gave the CT (Intercontinental ;) ) a bit of a wash!

[Aerobatic Flyer]

Chuck

but I suppose you're only lightly loaded

Extremely, if possible. In the planes I fly, it's generally half fuel, 1 or 2 seats filled out of 4/5 (the fifth guy would have to be thin...), and all superfluous equipment has been removed. That means gyros, transponder, all avionics, etc. We just have basic pressure instruments, a compass and a lightweight radio.

And, of course, I only do it for fun on nice days!

Philip Whiteman

Reading the first few words of your post, there is another measure which comes to mind..... ;)

I've been planning to try it for years...... :( :rolleyes: