Landing on grass rather than the hard stuff
 

It is a failing of my training I will admit but, to date, I have not landed on grass... a failing that I am keen to resolve. Does anybody vary their technique when landing on grass above and beyond obvious allowances for length of runway?

More than with tarmac you need to be aware of the state of the runway. Not just if it s wet and slippery, but it can also have potholes, be more undulating. I remember many years ago at Ipswich you were told to land left or right of the centre line because of bogs.

Always keep the weight of the nose, both on taxi, take off and landing to avoid prop strikes.

Grass is substantially more slippery when wet than tarmac, so be aware of morning dew, not just rain. So never break harder than you have to. I like to dump flap immediately after touchdown and only apply brakes when there is zero lift left, with a gentle pumping action with the control column pulled well back

Also -

1) taxi at walking pace. There isn't much clearance between the prop and the ground, and as the ground will be rougher than tarmac the aircraft will be more liable to oscillations, so take it carefully.

2) Ensure you phone ahead to get the latest on the state of the runway.

3) Be prepared to clean the underside of the aircraft if it is at all muddy - so best pick a day when your chosen airfield is firm.

Remember to use factors when doing your performance ie short grass.

....and the extra noise can come as a shock.

It's often louder and bumpier than what you may be used to with tarmac/asphalt .

It's a VERY sad refelection on the USA schools that not one of JAA approved ones will allow (or train) their pilots to land on grass.

3b. Don't forget the inside of the wheel spats. If the strip is very muddy, might be a good idea to remove them altogether, but check the POH for reduced cruise speeds. If it's a rental, talk to the owner first.

The other (obvious) thing to watch out for is that grass strips are usually, well, grass in a surrounding of grass. It's much harder to spot the runway, usually. Plus they are normally not ICAO marked with centerline & edge markings, approach lighting and so forth. It might help to view the strip in Google Earth before you set off and if you're not completely sure about the layout of the runway, do an overhead join or a low-level go-around before you land.

You'll also find that occasionally grass strips limit the strip width to less than half the available width by moving the "doghouses" (either black/white checkered or red/white checkered, doghouse-like structures) so that the rest of the strip can recover itself. Or they move the doghouses so as to create a variable, displaced threshold. So pay attention to the exact location of these doghouses (or other markers) so you land at the proper stretch.

Also higher chance of bird and other animals around as grass strips are normally found in rural areas.

Can't really blame the US schools for that. I learned in Florida and to the best of my knowledge there was exactly one grass strip within a reasonable flying distance. This one was a private field, requiring PPR and landing fees. Yes, there was a stipulation that students were not to land on grass (citing insurance reasons) but if there was a good enough reason, this could be waived. I think if I had insisted, I could have done a few dual, and maybe even solo landings and take-offs from grass.

There is at least one, I was taught to use a grass strip, granted not many times but enough, mainly we practised shorts and softs on the hard runway and then went over to the grass strip. (This was CPL training though)

Many good thoughts here...

Add to them that many grass runways are more casually built on the ground that was found. The result can be runways with unexpected hills, and slopes, which can be laterally across the runway.

For grass runways in parts of the world where winter takes hold, expect a season of thaw, where a runway may look inviting, but be unable to support the aircraft. Private runway owners don't always "X" a runway, which is intended to be closed, and a flyover inspection will not tell you the firmness of the ground. Therefore at certail times of the year, the only way is either a first hand (foot) walking inspection, or a report from a person you really trust. My runway has taken as much as six weeks to firm up, once the snow is gone. Also, the condition in one part of the runway, may not be the same as that in other parts, as has been pointed out.

That said, a smooth grass runway is a delight. One of the many benifits is the fact that the aircraft will slide. This make for much nicer crosswind landings, as touching down with a little crab, does not result in chirping and lurching. This makes grass runways very desirable for tailwheel aircraft. One of the taildraggers I fly, I will land on grass unless there is just no choice.

It is my opinion that if you are regularly making full use of the friction of a dry pavement runway for braking, you are probably using too much brakes. Most GA aircraft into thier "comfortable" runways, should require only a minimum of braking. My grass runway is 2000' long, and I rarely use brakes at all. The less I use them, the longer they last!

Aircraft renters are reluctant about grass runways, just because of the "unknowns". Three of the schools in my area have grass runways which they "approve" for students to use.

With the correct permissions, go look for some grass, it's excellent!

Pilot DAR

Aim to land somewhere near the numbers. Grass strips tend to be 800m or less, so avoid touching down two thirds up the runway. I know it sounds obvious, but it's amazing how many pilots used to mile-long runways don't realise they've less room to play with. But don't aim for the numbers at the expense of the nosewheel. I've witnessed more than my fair share of 'carrier' landings that ended in embarrassed pilot and shock-loaded engine. Keep that nosewheel up!

If you do end up floating two thirds down the runway before touching, don't be embarrassed about going round and trying again. Better that than an expensive trip into a ploughed field or through a thick hedge.

Cheers, jez

Another small problem is that at this time of year it seems to be easier to pick up carb icing during taxi on wet grass. Always worth an extra burst of carb heat before you take off, as I know to my cost.

The handling of the aircraft is type specific and comes with practice but here are a few top tips:

Virtually all grass strips are undulating to some degree which increases the likelihood of the aircraft bouncing. Handling the aeroplane in a way that would yield a greaser of a landing on tarmac, may still result in bounces on grass - if you still have some speed and lift on, a fairly small bump can launch you back into the air. (Taildraggers are more prone to bouncing than others). If you do bounce, hold the attitude and let it settle back on. If you pitch forward to try to 'encourage' it back onto the ground you may break the nosewheel off!

If the bounces are BIG or their amplitude is increasing go around. If you don't you are likely to end up hitting the ground hard either by flying the nosewheel onto the ground or by running out of airspeed and stalling too far above the runway.

All the time you're flaring or bouncing, you don't have weight on the wheels and your not slowing down effectively. If you're using a short strip you need to land in the right place and get the brakes on. If you don't and the end hedge is looking critical go around and get it right next time as I recently had to on a bumpy 350m strip in a bounce-happy taildragger.

As mentioned be aware of takeoff performance issues on grass. One trap is that you may well be able to land at a strip that you cannot safely take off from.

Take care taxying from grass onto concrete and vice versa. There is normally a lip that can lead to prop strikes. Take it slowly and at 45 deg or perpendicular in twins. If a grass runway has white concrete markings embedded into it you may want to land so as not to run over them at speed. You don't have to land on the centreline.

At farm strips or small airfields you should probably inspect the runway before use. It is not unknown for holes to be dug, animals to be present, agricultural machinery to be left about, long grass or waterlogging.

Two notable grass strips I've used recently are Fishburn which is perched on the top of a convex hill with significant slope either side of the brow (you can only see a fraction of the runway when you're on it, so you want to be very sure that there isn't a tractor cutting grass over the brow) and Stoke which has a billiard table surface but is fairly short, curved and with big obstructions adjacent to the runway.

Lots of good advice so far. I'd add that it's actually easier to land on grass, all other things being equal. The surface has a texture which allows height during the flare to be more easily judged, and as someone else pointed out, if you are not quite aligned with the runway at the point of touchdown, the wheels will slide a tad sideways and no-one will know, whereas on tarmac there will be a telltale chirp of tortured rubber, and a lurch as the aeroplane is dragged straight by the tyres!

SSD

Molehills
 

I fly from a grass strip in a taildragger.
No 1 problem in the winter is molehills,they could spoil your day ,so if possible get an on site airstrip condition opinion before leaving.
As mentioned if the strip is alongside grass it can be difficult to see but normally you will be alonside cropped land,mostly brown-green in winter.
Good luck.
Lister:)

I was fortunate enough to get my license on a grass strip. All the above remarks are good, especially being ultra cautious at time of thaw when my training operator would move a few planes to paved airports:ok:

A C-152 nosed over on our gliding field in such conditions:ouch:

I prefer firm grass to pavement.

As said, be prepared for more noise and bumps. Gravel and recently planted crop fields can be very noisy.

thanks for the advice - it is comforting to know that you take the time to help a new boy.

Looks like as with most things prior planning helps to stop P*** poor performance.. I look forward to the chance to put it into action ..

Currently I think Popham may get the honour of my first arrival of this type.

And that will introduce a few extra things to think about depending on which runway you have to use. I would suggest that you try somewhere a bit simpler for your first grass landing e.g. Old Sarum.

Hmm--them things, apart from their aerodynamic function, also stop rocks being thrown towards the fuselage/wings. That's how I punched a nice fist-sized hole right through the aileron in a Jodel last autumn (here's a pic of the offending "runway")

Compton Abbas in the summer is such a friendly welcoming place it is so worth making the effort to find it! It can be tricky to find from the north east, but once you know where it is, it gets easier. Try and pick a day when the BBQ is fired up!

Or try Rochester, for a slightly amusing approach over the River Medway then the town! And then taking off over the motorway!! It is a great place for t&gs!

Of course if you are lucky, sometimes they open runway 21 R GRASS at Biggin Hill, tends to be around air show time! That was fun, quite a displaced threshold compared to 21 L Asphalt!!

Seriously if you have not done may grass landings, it is so worth getting an instructor and doing a tour of several places with grass runways. We did a great afternoon from Biggin to Earls Colne and Panshanger a few summers ago. Lunch at the golf club at Earls Colne, and tea at Panshanger. Such very different places, and a great experience.

I own a Piper L-21B (that is a 1953 Super Cub for civilians).
It is leased-out to a flight school/airwork operator. Grass strip available.
They used it for training, glider and banner tow.
The manager informed me that he recommends his pilots to use the grass.
If only one thing, he said, it saves wear of the tyres.
Besides that, I am sure that L-21s were meant to use grass fields...
xxx
:D
Happy contrails

Don't land on the grass at Dargaville in the Winter. 4ft. amsl. - and the river is about 10ft away - very soggy.

Seriously, grass can be fun, but note the above comments, all valid, we tend to avoid grass at our local field because of the gorse, even when cut regularly it is like landing on tin-tacks. Fed up with mending punctures, but apart from that grass doesn't wear the tyres out as fast. Bit of flap, short field take-off technique off the seal helps that problem. I find my taildragger slightly more controllable on the grass, steerable tail wheel is less skittish and it slows down quicker, so I don't have to mess about finding the brakes pedals located between the rudder pedals so soon, and losing rudder control as a result. Enjoy.

Backpacker makes a good point here.

If you have spats fitted, also check that they are not jammed with grass, as this combined with friction has caused fires in the past.

Good grass runways are delightful (e.g. Fowlmere in the late 90's, ealry 2000's when I lived in the UK), but poor ones are not :\

Having scanned the thread, there is plenty of good advice, enjoy.

Keygrip

IIRC correctly, they do not refer to them as grass runways, which always amused me when asked to sign a declaration that I would not operate the aircraft on 'sod' runways.

I once did try to explain that not all runways that were sods to land on were constructed from grass, but the joke got lost in the translation :}

Grass is OK if smooth; it is what you find in the grass that might be a problem.

Potholes for example. I had a pothole prop strike when new; £20,000.... And the airport washes its hands of liability. So you, the pilot, need to be vigilant. If in any doubt, get out and walk the taxi route - even if there is a queue behind you. They won't be footing your prop strike bill :)

I tend to not do grass in the winter because the plane gets covered in muck, and due to the rut problem below.

Another thing is to get hard parking if possible. A lot of grass runway airfields have a hard parking area. I had to get my plane pulled out (from a rut) with a vehicle more than once, and most fire crews doing this will just do it by the nosewheel :ugh: so ripping off the engine mount. One needs two ropes, pulling on the main wheels.

Otherwise, grass is fine. Taxi with the yoke all the way back to relieve the nosewheel pressure, and do a "soft field" take off whenever possible. I never did those in the JAA PPL; only the FAA one teaches them, it seems.

However, hard runways can be as bad. I know of some (Elstree and Spanhoe being the worst) which are covered in stones, and the users there must be getting a high rate of nicks. These translate into early prop overhauls, or unneccesarily early blade scrappings during scheduled prop overhauls, and that is 4 digits. The technique is to avoid high power slow speed taxi over areas where there are most stones; build up speed before these and then cut the revs. I don't know why somebody doesn't get a broom... at least with grass you don't get this problem.

Having said that, the worst runway I have ever been to was Heywood Farm - a scary experience I am not repeating. Followed by a £200 cleanup job.

That's one hell of a dry-cleaning bill :eek:

Lol@Katamarino

I was taught to perform a short field take off when taking off from grass, which nobody seems to have mentioned. I wonder if it's just me being over cautious. I'm always slightly more nervous taking off from grass than concrete that extra roll is just a little bit more unnerving...

Would endorse those recommendations for nice grass runways - Panshanger, Compton Abbas, Old Sarum all nice (though the latter has quite a hump in the middle - looks alarmingly short when you line up on 08!) and all three have nice cafes, too.

Also recommend Goodwood (Chichester) where your arrival on grass is always greeted by a courteous 'Welcome to Goodwood' over the radio. I've not yet bounced there so I don't know if you get repeated 'Welcome...' for each bounce...

Tim

Paul

Just being grass doesn't mandate a performance take off, IMHO.

What might make the difference when comparing hard and grass is the effect of the factors applied to wet, long (etc) grass, leading one to operate that way.

I flew regularly out of a 700m grass runway and I would run up the engine against the brakes to 2000rpm to see the T&Ps stabilise and use flaps 25 to shorten the ground roll, flying off at around 55, instead of 65. As there were no obstacles ahead, I would trade early lift off for poorer initial climb out.

In principle, on a 700m hard runway, I'd have used flap 0.

The law of the situation applies and I don't think that you are being over cautious, you are still a relatively new PPL taking a conservative view and thinking about what you are doing - that's good airmanship in my view.

Have you seen Safety Sense 7 leaflet form the CAA?

http://www.caa.co.uk/docs/33/ga_srg_07webSSL07.pdf

The performance factors in this book are felt by some experienced pilots (I am not in this experienced category) to be ultra conservative, but they make a good starting point when considering take off and landing performance.

I think you mean a "soft field takeoff"?

A short field takeoff leaves the nosewheel down all the way until Vr and then you climb aggressively at Vx. This is best done on hard runways, but can be done on good grass too. This one is easy.

A soft field takeoff is where you pull the nosewheel up very early in the takeoff run - maybe at 30/40kt in a 60kt-stall-speed plane - and the whole plane floats in ground effect until Vr, then climb away as normal. You don't want too much crosswind when doing this one :) This one needs practice because after the initial aggressive pull-up to get the whole thing into ground effect, you have to increasingly push forward on the yoke, to prevent the plane floating up too high and out of the GE (which will stall it and it will plunge back down).

IO

At the risk of being pedantic, your description of a short field take omits the difference between clearing an obstacle or not.

For the former, the climb at Vx must be maintained until safely clear of the obstacle (having first caclulated that this is feasible), whereas if no obstacle is involved, 50' is a safe height to release the back pressure and start thinking about accelerating to a safe speed/cleaning up (if necessary) and looking for Vy.

Reference is Airplane Flying Handbook - Google Book Search

Not trying to be smart, as I agree with you in the point you are making, just to be absolutely clear for others reading who do not have your considerable experience.

Landing on the hard stuff


Let's see, assuming Scotch has a density of about 0.8 then your average floatplane should be ok - it would float a little lower but bouyancy margins should be OK.

Viscosity is lower than water but which would affect the takeoff run more, lower viscosity, the plane floating lower in the liquid or pilot failing to meet "bottle to throttle" requirements?

So where's this lake full of hard stuff then?:p


I'll just collect my hat:)

...don't forget your coat :rolleyes: :}

All good stuff here and worth noting, but don't get too frightened! Grass isn't scary, just a few different hazards.

To add to a point Backpacker made about lighting and marking, grass runways tend to "look different" on approach. They tend to be all different shapes and sizes, often with the runway not quite so clearly defined as a nice rectangular strip of tarmac. You get fewer cues to being on the right glide path, and when I was learning (and afterwards) I tended to find the first approach at a different grass strip could be a bit ragged. As always: never be too proud or too scared to go around, even from runway height if necessary.

Fredacheck

Interesting point about the visual appearance of grass runways.

This never bothered me, although I can well see how it could be confusing.

My worst optical illusions were (a) the very wide runway at Manston with the hard extnsions that made it nearly wide enough to land on - really b*ggered ujp my depth perception and (b) landing at night on runways with only edge lighting - hello trench!

Also, easier to find a grass strip in winter, when surrounded by brown plouhged fileds, than in summer when they were all green :\

It doesn't tend to bother me now with my MASSIVE 400-500 hours of experience (!) But I can remember it was one of the many things that confused me earlier.
Too true! Fenland is my bete noire. Lots and lots of rectangular runway-sized fields all around.

IO
 

IO

True, I had never seperated out a grass take off from a short field take off, in my mind, but yes you lift the nose up earlier and use ground effect on a grass strip take off.

FREDACheck

For me Middelburg was the worst field to spot from GoogleEarth http://maps.google.co.uk/maps?hl=en&ie=UTF8&ll=51.515233,3.714366&spn=0.041662,0.1112 37&t=k&z=14. Didn't make it out there last year due to fog, but hopefully this year...

FREDACheck

Well you have a bit more experience than me!

But, even at low hours, I never even noticed the things you mentioned, so I wonder if it is more of a physiological thing? i.e. the way our individual eyes and brain are wired.

I've always tended to land a foot/18" left of the centreline and even in a flight sim with a TRE from a major airline observing, I did the same repeatedly and he couldn't see any tangible reason for it :\, just saying it wasn't dangerous and it was consistent (they lilke consistency.)

I do agree about Fenland though, even with VOR and GPS, you could be nearly overhead and still not spot it!

Paul

Not being pedantic, but IO said 'soft field.'

This could include other surfaces such as sand, but not include firm grass.

An important difference when considering take off performance and the best technique to use, for instance whether to use a rolling take off or run up against the brakes on a short strip.

No, Middelburg (actually called Midden-Zeeland, EHMZ) is easy. Just ignore the field altogether and look for the point where you join downwind. You need to join from the North in any case, so follow the "Veerse Meer" lake until almost its southernmost point (actually the little harbor just NE of the southernmost point), head due East or West at 700 ft, look left or right as appropriate and hey presto, there's the field.

But in general, yes, it helps to use Google Earth to spot a few useful landmarks to find the entry point in the circuit, in addition to the runway itself.

F3G - indeed. There is no reason ever to climb at Vx, except to clear an obstacle, or to impress the spotters :)

Sand ?!
 

Ouch has anybody actually done that ? Doesn't it positively spew sand all over the place ? :eek: