How long is your grass?

[SATCO Biggin]

The other thread currently running on the subject of operating from grass strips has acted as a catalyst for me to bring up this associated subject.

I have a running battle trying to get the aerodrome authority to cut our grass taxiways to a decent short length. They on the other hand stick rigidly to CAA guidelines on 'Long Grass Policy' and how it deters birds (feathered variety) from infesting your airfield and causing a safety hazard. Ideally 'long grass' should be between 6 to 8 inches long (150 to 200 mm). OK, fair enough, I agree with the logic that long grass of that specified length is an aid to safety.

The CAA guidance goes on to say that 'close cut' or 'short grass' should be kept to a minimum area, like just 1 metre around sign boards, runwway lights etc. Hmmm! maybe I can go along with that as well.

But I do get a bit tetchy about their next statement that grass manoeuvring areas may be kept up to 4 inches tall (100 mm). Now that is pretty long and draggy for a runway or taxiway. I have two grass taxiways that look like rejects from the 1960/70's long hair era and that is the way they are staying because that is how the aerodrome authority wants it.

How long (in the tall sense) would you consider the grass should be on a runway or taxiway?

Regards

[Flyin'Dutch']

On the RWYs as short as compatible with the management of the grass (as in too short may cause bald patches which turn in mud when it rains)

Would not lose too much sleep over a bit longer on the TWYs.

FD

[FNG]

At Waltham, the rule is that the grass is only too long when you can no longer see the CFI asleep near the rotary fuel bowser.

[TonyR]

I set the cutter to 3" and at the moment cut it once a week so it never gets above 4".

[bar shaker]

Grass on the strip is around 4" at the mo. No small birds to speak of but the bloody pheasants love it :mad:

What was the outcome of the guns in aircraft thread?

[Big Hilly]

Blimey Pete, I always suspected that all you SATCOs did all day was sitting around watching the grass grow. . . . :D ;)

All the best,

BH

[stiknruda]

My gangmowers are set to cut 1.5". I never adjust cutting height but do check blade/backplate gap every time I use them.

Depending upon how bored/busy I am when I tow them, I'd guess between 60 and 90% of the strip is cut to that height. (Busy/bored - tend to pull them faster and they become less efficient) In summer I tend to cut it every 10 - 14 days, but really that is because it looks neater and keeps the clover under control.

If the grass is too long - it hides dog and pony pooh. If it is wet it makes decelleration tricky, too!


Stik

[SATCO Biggin]

Well the opinion so far is that 3 to 4 inches is acceptable. Still looks a bit shaggy to me !! Maybe taildraggers fair ok but I wonder if the nose-pushers might end up with green prop tips :eek:

Blimey Pete, I always suspected that all you SATCOs did all day was sitting around watching the grass grow. . . .

No....I sit around watching the subordinate ranks cutting the grass with nail scissors and sweeping the glidepath with a broom whilst savouring a Pimms by the pool. :p

Interestingly the CAA quote 'long grass' as not being very long. In fact you can still see a pint beer glass above the tops. Wonder how they came about that one? Mathematical calculation or practical experience? Probably the only time a beer glass has been used a a unit of measurement in a CAP document.:D

Regards

[Monocock]

This is an interesting one....

I am fanatical about my grass length and have been known to cut it three times in one week! I hate seeing balls of dried grass as they love to jump up inside spats etc and generally make the strip look less tidy.

Put it this way, if the grass touches my ankle when I walk on it everything is dropped to get it cut!! I aim for one inch and then allow it to get to three inches before the next shave.

Early morning mowings are not good as the dew makes the cutter work less efficiently.

A good hot day is good as the grass is lacking in moisture and doesn't "ball up" when it goes through the cutting deck.

But the best..........is at 9 pm!! There are less flies to fly in your mouth and down your shirt. The phone doesn't ring causing the mower to have to be shut down, the wind is normally non-existent, the grass is still lovely and dry and the four pack of lager stays cool on the floor under the seat!!
:}

God I'm a sad b*****d:8

No doubt the chap I share the hangar with will make a suitably sarcastic post about how I spend as much time flying the tractor mower as I do flying my plane!!!:D

[TonyR]

Monocock, What type of mower do you use?

I just use a 7' grass topper behind our old MF135 with well worn tyres, set to its lowest, but thats still a bit over 2".

I take your point about keeping the grass short and cut when dry so that you avoid clumps when cutting.

I find that it makes very little difference to the take off run in the Rallye unless the grass is over 5-6".

[Potter1]

Monocock,

Now you have a SLOW plane you spend a lot longer in it!:O

Although I imagine dodging the wildlife on the strip does take sometime!

P...:ok:

[Monocock]

TonyR

I have a New Holland machine that has a 5 ft deck out front. It is a purpose made job similar to the ones the council boys use on the verges and it cuts at 12 mph!! It has a great little space beside the seat for the Sony CD Walkman and plenty of room near the feet for the Carlsberg...:ok:


Potter1

To make your departure more interesting this afternoon I have just left 300 sliced apples all over the strip. By the time you get there there will be around 400 deer to dodge:E :}

[Potter1]

It's not the deer I'm bothered about. It's the tigers and lions that are after the deer/hares/rabbits & pheasants that are the real problem!

P...:\

[Monocock]

When I bought Longleat I knew it wouldn't work mixing the safari with the airstrip. Hey ho, it all adds some excitement.#

We don't get many visitors here !!:D

[Potter1]

Apparently, (I’ve been warned by someone) when your leased expecting it, they grab hold of the tail and push you off the edge of the runway onto your nose, cause lots of damage. IT’S HAPPENED BOFORE!!!

P...:O :ouch:

[TD&H]

Hello SATCO

How about getting the grass cut on 11/29? Its starting to come through the tarmac quite seriously in places, there may be signs of weedkiller on some of it, but if the management don't try some pro-active maintenance then they'll have their perfect excuse to close the runway (or is that part of PL's plan anyway?)

If you find a spare pint hiding in the grass point me to it!

Cheers H

[whatunion]

whatunion says, have you seen the length of the grass at the wherethefecarwe international

[Sir George Cayley]

Is it the law that grass has to be kept between 6 and 8 inches or is it a recommended practice.?

If it is the latter then presumably you could have it cut to bowling green height.

Trouble is that should an a/c suffer an accident caused by a bird strike and the owner resort to litigation then your failure to meet best practice woulld count against you as in the case of Fred Olsen Lines o/y vs Norwich Airport.

What is your bird hazard assesment? Does it show the likely levels of risk?

If cutting the grass has no adverse effect on bird numbers or if you have Britains best bird control unit then carry on I say.

If not I'd reach for CAP683 and just accept that for the greater good your greensward will have to offend your eyes


Sir George Cayley

[SATCO Biggin]

How about getting the grass cut on 11/29? Its starting to come through the tarmac quite seriously in places, there may be signs of weedkiller on some of it, but if the management don't try some pro-active maintenance then they'll have their perfect excuse to close the runway (or is that part of PL's plan anyway?)

I have mentioned to Ground Ops that 29/11/ tarmac runway needs mowing !! :uhoh: There is not much risk of that runway closing for political reasons that I will not waste time clarifying now. The biggest problem will be the cost efficiency of keeping the surface useable.

Is it the law that grass has to be kept between 6 and 8 inches or is it a recommended practice.?

Its another one of those aviation 'grey areas' again. As you quite rightly suggest if we are not seen to be using 'best practice' and CAA advice then something gets a nasty strike then we leave ourselves a bit exposed.

If not I'd reach for CAP683 and just accept that for the greater good your greensward will have to offend your eyes

Dont know where CAP683 'Assessment of Runway Surface Friction for Maintenance Purposes' comes into the grass argument? :hmm:

Regards

SATCO

[Sir George Cayley]

Sorry SATCO tired typo..............

should have been CAP680 Aerodrome Bird Control

Happy reading

Sir George Cayley

[TC_LTN]

I was pleased to note that at the Butty Fly-In that Bourn operate a 'small boulder policy'. Rubble and rocks along taxiway Bravo have been carefully managed to ensure that none of them exceed 7 inches in diameter:D Mind you I may be exaggerating, I have never been very good at judging 7 inches, and they may have been nearer 3 inches in reality;)

Seriously, I am far from convinced about the Authority’s current ‘Long Grass Policy’. I think a reasonably manicured aerodrome is far preferable, easier and safer to operate from than large areas of 'long' grass. At Old Warden we cut the aprons, taxiways and runways relatively short while the majority of the remaining aerodrome is cut to about 5-6 inches which facilitates landing in just about any direction with our old and fragile types, if required. The ability to actually keep the grass at lengths of 5 plus inches is quite difficult to achieve and can often result in long grass being chopped short resulting in large amounts of cut grass laying around which, of course, if dry is easily ingested or if wet, forms clumps which stick on or in everything.