Farm airstrip length

[jetjr]

Looking at airstrip on pretty hilly farm

 

Height would be 3200 0ft

 

Length runway is what I'm trying to work out for J200 or maybe C172/180.

 

Jabiru spec says need 645m which seems excessive.

 

Best I can get is around 450 m of strip. is it enough?

 

Next q is about hanger floor, how to do it cheaper than cement.

 

Will I need council ( or neighbour) approval for the shed or strip?

 

 

[metalman]

I go into a mates place that's a bit more than 450m sometimes, his strip is all about nailing the speed and being in the right place at the right time, I'd say it depends on the approach and the go around room, most of our lighties will get in and out on that but you can't stuff around floating along while the runway disappears behind you, I spent ( and still am ) a few hours practicing putting the wheels down exactly where I wanted them before going into his place,

 

 

[pmccarthy]

There is a good discussion of pressure altitude and take off length in December Sport Pilot.

 

 

[skeptic36]

Re the hangar floor, I have compacted gravel ( high clay content is better because it is not going to get wet) then a layer of plastic, then second hand carpet. I am very happy with mine.

 

Re the airstrip, don't know your situation but if you are happy with one way, you can have a bit of gradient in it and get away with a bit shorter length, downhill aids your takeoff and uphill slows your roll out. Mine gets steeper the further you go along.

 

Regards Bill

 

 

[Guest Maj Millard]

I routinely go in and out of the short strip at Heathrow (photo) but as MM mentioned you must nail the approach speed and get back at idle at the right point, and always be ready to pour the coals on for go around if you get float, which can take you too far down the runway.

 

If I'm not wheels on at the mid point, it's power up and out of there, for another go. Approach is either over cane or mangrove at the top end. Cane currently is around a meter and a half high, but will go up to about 4 mts over the year which makes it more character- building for sure..This goes for any shortish field ops, you must come over the approach end at minimum airspeed hanging a bit on the power, soon as you get rid of power you should drop on...you need some strip room to pull up.

 

Jabs are not ideally suited to short field ops either landing, or take off, although there will be those who disagree with that of course...........Maj......

 

 

 

[biggles5128]

Be very carefull with carpet on the floor of a hangar, the static electricity build up is a big risk when you walk on it and then open your fuel cap.

 

Re the hangar floor, I have compacted gravel ( high clay content is better because it is not going to get wet) then a layer of plastic, then second hand carpet. I am very happy with mine.Re the airstrip, don't know your situation but if you are happy with one way, you can have a bit of gradient in it and get away with a bit shorter length, downhill aids your takeoff and uphill slows your roll out. Mine gets steeper the further you go along.

Regards Bill

[Teckair]

Looking at airstrip on pretty hilly farmHeight would be 3200 0ft

Length runway is what I'm trying to work out for J200 or maybe C172/180.

 

Jabiru spec says need 645m which seems excessive.

 

Best I can get is around 450 m of strip. is it enough?

 

Next q is about hanger floor, how to do it cheaper than cement.

 

Will I need council ( or neighbour) approval for the shed or strip?

That would only be long enough on a good day, so not really long enough. Over Burden might be OK for the floor. You need council approval for the shed, when you put a strip in like that it is best to get in sweet with the neighbors first.

 

Richard.

 

 

[FlyingVizsla]

If the strip is to be used by others (friends, crop dusters etc) then you have an obligation to make it as safe as you can for the aircraft you approve to land there. CAAP 92 (1) (1) is a good place to start http://casa.gov.au/wcmswr/_assets/main/download/caaps/ops/92_1.pdf As an unlicensed strip it is up to the pilot to determine if it is suitable to land on, in which case they will most likely rely on your description, so record height, gradients, length, width, surface (grass, short/long wet/dry) and likely wind strengths & direction - erect a wind sock or other reliable wind indicator. The pilot can then work on his Take Off & Landing charts to determine if it is suitable. Delineate your strip - old tyres painted white are a cheap solution - your local tyre shop has to pay to have them taken away - so they will gladly give you a pile.

 

 

 

Contact your local council about any requirement from them for the establishment of an airstrip - they may have a process, or they may not - in which case make sure your neighbours are agreeable. Your Council may require a building application for the hangar; gone are the days when a farmer could do what he liked on his land.

 

 

 

We have looked at many properties to build an airstrip. Our criteria:

 

• No approach or departure over neighbours' houses, horses or power lines
   
   
  
• Standard approach & departure area clear for recommended landing profile & 50' obstacle clearance
   
   
  
• Safe for; go-around, precautionary search, area ahead for engine failure, run off area for brake failure
   
   
  

 

 

The C172 has a performance chart in the Pilot's Operating Handbook. I will try to find the charts so you can determine if your strip will suit.

 

 

 

Sue

 

 

[turboplanner]

Looking at airstrip on pretty hilly farmHeight would be 3200 0ft

Length runway is what I'm trying to work out for J200 or maybe C172/180.

 

Jabiru spec says need 645m which seems excessive.

 

Best I can get is around 450 m of strip. is it enough?

 

Next q is about hanger floor, how to do it cheaper than cement.

 

Will I need council ( or neighbour) approval for the shed or strip?

As pmcarthy has hinted at there are five key elements other than length you need to think about

 

Pressure altitude: At 3200' the length requirement will be significantly greater than sea level

 

Ambient Temperature: This will become a critical part of operations at this altitude

 

Slope: This may help matters in getting speed up

 

Surface: If you've been flying out of a major field, wet grass and soft surface will be new and very significant

 

Angles of approach and departure: Trees in the splay need to be measured to ensure you don't find yourself 3/4 up with no more climb capacity as I did once

 

At Sea Level

 

The shortest grass strip at Moorabbin was 750 metres and that was comfortable to get into with a Cherokee or 172

 

The gravel strip at Tooradin is 500 metres, and while there would be no problems putting a 172 down there, I found I had to absolutely concentrate with the Jab, and on one occasion where I got caught by a gust of wind I finished up a lot further down the strip and if I hadn't been doing a touch and go would have had trouble stopping before the fence.

 

So the 645 m recommended by Jab sound s reasonable.

 

As Metalman says you can practice spot landings, but correcting the results of a burst of wind can take you a further 20 metres down the strip.

 

Paddock grass can be treacherous; I laid out an 800 metre strip in a paddock in South Australia at one stage, and took off with a full load after medium rain. Although the grass was reasonably short, the combination of west grass and softer soil had me thinking the brakes were still on. It just would not pick up speed, and it's the only time I've ever had to start calculating for a shut down.

 

The Cessna POH will have graphs for the envelope with temperature, pressure altitude, weight etc, and that will give you an accurate performance for the aircraft (not necessarily the pilot). I would add at least 30% to that and see what that looks like.

 

I suspect you're a bit short. The accident reports always seem to involve visitors to these short strips rather than the owners.

 

Road base or similar compactible material will work for the floor, and I've visited plenty of properties where the floor was whatever was over the rest of the paddock, but if you want to keep dust out of the aircraft a couple 0f thousand dollars on concrete is well spent. You can cut down the volume if you won't be putting road vehicles in it.

 

Planning

 

I would approach your neighbour to see if he would sell or rent you another couple of hundred metres of strip.

 

If the property is far enough away from a City and property acreage is big enough he may even let you just use it. You would pay for all the fencing, and he might be more interested if you were to let him use the strip whenever he wanted for grazing. If you haven't had stock before, this would be the better solution anyway.

 

That discussion isn't going to change anything planning wise because the procedure is usually:

 

1. Visit the Council Planning Department, or look up on the web to get the Planning Scheme for your district. Most Councils will have this either on their own website or the State Planning website - they will have districts/areas set aside for Residential Use, areas for Industrial, Special Use (sewerage farms etc), Flood Zones, and General Farming.

 

Once you find the scheme for you location it will usually show:

 

Uses not requiring a permit

 

Uses subject to a Planning Permit

 

Prohibited Uses

 

2. Go through the process very carefully

 

If you can build a shed the size you want without a planning permit (you may need a building permit to ensure the structure and design are sound), then you can go right ahead

 

If you need a Planning Permit, then the best strategy is to lay out your plan, discuss it with all your surrounding neighbours quickly (or they will get their heads together and decide they don't want the noise).

 

Then you put in your Application for the shed. If your neighbours have all agreed you make sure to mention that, because if the Officers check and find that's correct they will most likely approve it under delegation.

 

If they jack up there will be a mediation meeting, but that usually doesn't carry much weight, so no need to get too excited at that.

 

Around that time it's important to talk to each Councillor and explain what you want to do, especially how many flights.

 

When it comes to Council you'll either find them earnest, trying to do the best for everyone or you'll realise they've screwed you. This Meeting decision doesn't matter all that much either.

 

What really counts is the Tribunal or whatever it's called in your state, and that's where it's critical to hire a Planning Consultant, because the decision will be made on Planning Grounds and "We don't want the noise" counts for very little, but compliance with the Act does. I've seen many people lose cases because they tried to handle it themselves or hired a solicitor instead of a Planning Consultant, and the solicitor missed key Planning criteria.

 

 

[turboplanner]

Important points from FV, once its a strip you have a duty of care for all safe operations. If only you would be using it, I'd have permanent white crosses on it.

 

 

[jetjr]

Thanks for all that

 

Just looked through J200 POH more closely- which is pretty rough in places as it was done 10 yrs ago

 

They suggest 350m required at sea level, plus 365.5 required for this height thats 715m required to 50ft, plus factor, PLUS we are carrying another 55kg since then - hang on not sure these numbers arent for J200A which is 700kg MTOW

 

Not too worried about landing its take off, one end slopes away into deep gulley so no trees etc there, other way has few big old trees. I guess the real question is ground roll, other obstacles can be adjusted. Best possible would be 600m with free air each end.

 

First time ever I wished I had longer wing on J230.

 

Already tense with neighbour, has demanded we pay $60K to fix council road up to allow the subdivision.

 

 

[FlyingVizsla]

Already tense with neighbour, has demanded we pay $60K to fix council road up to allow the subdivision.

The Council will decide what contribution you must make to road improvements. I guess this is an "objection" to the subdivision made by neighbours in the response to the Public Notification. Don't get into negotiations with them, leave that to Council; it is their road, their decision, and they will have guidelines regarding road works contributions or work you will be required to undertake on their behalf. Most importantly, don't get the neighbours off side while giving them extra ammunition about airstrips - or it will end up with wild accusations about turning it into a busy airport, frightening the horses, chooks off the lay, fumes, fuel & noise threatening human health and starting bush fires.

 

 

 

It is common for neighbours to "object" - it may not be aimed at you personally. I did development applications for a rural council, and the objection process was used to request a better road, even if it was only a boundary reconfiguration. Keep the airstrip idea out of the subdivision process.

 

 

 

I was trying to find the Take Off & Landing Charts for a C172 similar to the charts in my C152 Flight Manual. These charts have pressure height, slope, surface type, temp, wind, distance & weight, to give you an idea of the distance needed on your strip. The C172 table (for a sealed level strip) notes for a dry grass strip to add 45% to the landing distance and 15% to the take off. This is based on a new aircraft. In reality there are many factors that introduce degraded performance as aircraft age and we hang more things off them.

 

 

 

Sue

 

 

[Teckair]

Maybe a Savannah might be best, if you manage to get in good with the neighbor?

 

Richard.

 

 

[turboplanner]

If there is already a neighbour problem, the momentum usually keeps them objecting, so what FV says and leave out my consultation advice.

 

Take off is more certain than landing, i.e. follows the aircraft power/specification. On this length you need an EFATO paddock so you can decide it will be slow enough to het the end fence safety, or fast enough to get over, and can ingrain that into the subconscious.

 

The 172 will also reasonably repeat the short field landing figures, and you have plenty of brakes, although I see plenty drifting to 800 or 900 metres at Moorabbin and holding everyone else up.

 

I wouldn't trust the Jab to do it 10/10 though with those little control surfaces, more wind susceptibility, and brakes that would have widened Henry Ford's eyes momentarily.

 

 

[facthunter]

The higher your density altitude the less performance margin you have for grass, soft soil, slope and climb performance. All you calculations become more critical and you have to achieve a higher actual speed, as it all happens according to IAS. If your DA is 5.000 feet and your plane will only climb to 5,000 feet at ISA, at your actual weight then you won't fly. It's surprising how little performance is left, even if you could fly to 8,000" ... Nev

 

 

[Bruce Tuncks]

I use a 550m farm strip sometimes, at 600 ft altitude.

 

The official specs all assume you are at maximum weight.

 

If you can operate lighter than max weight, then the runway length required becomes less in reality if not officially. So I only use the farm strip with no passenger and it is quite long enough for my 235kg empty-weight SK 2200 Jabiru.

 

But one day I came in too high and instead of going around I persisted with the landing and had to brake hard and gave myself a fright.

 

Before using the farm strip, I did tests at Gawler and found that 350 metres was ok most of the time, but there is another big consideration, and that is the wind. At Gawler, there is a cross-strip while at the farm there isn't. So there are lots of times the farm strip is not smart to use on account of cross-winds.

 

regards, Bruce

 

 

[planesmaker]

Depending on the gradient you may be ok but the altitude will be a concern on a warm day. Surprising how much more strip needed for high density altitude with a short wing jab. Also brakes aren't too effective on a j200. Also lenght of grass if that is the surface. Lots of things to consider especially when POH says a longer strip is required. Tom

 

 

[jetjr]

The CASA doc is quite good and recommendations appear ok until you add them to TODR, ends up needing 2000m x 60 m without any obstacles much

 

I reckon i can get 600 m airstrip plus 280 clear each end, around 15 trees will have to go which is a shame.

 

Jabiru dont have any data much on take off distance and DA adjustment, just 100' above sea level data, old manuals say 115 m for every 1000' PA increase.

 

South African s have made nice chart for J430 TODR vs DA, wind and weight, ground tested and everything. Much shorter than POH numbers.

 

Is it resonable to work out percentage more TODR J200 needs, ( around 14%) than J230 at sea level and use these J230 numbers as a guide?

 

Ill speak to Jabiru when they return to work but dont expect a clear answer.

 

 

[Yenn]

Why would you talk to the council. Give a beaurocrat any reason to stuff you around and he / she will do just that. Tell them nothing and take them nowhere. You can work out what length you need by doing some tests. A C180 will get in where a C172 or jab would stand no chance. They can get off in less distance than a Thruster, I know because I lost a bet on that.

 

 

[jetjr]

Thanks Yenn, good info, in the back of my mind is setting hanger etc up for C180 if i ever wanted to.

 

Surprisingly it would use much more hanger or airstrip it seems.....dollars is another matter

 

 

[Gnarly Gnu]

Next q is about hanger floor, how to do it cheaper than cement. Will I need council ( or neighbour) approval for the shed or strip?

If security isn't an issue a tensioned fabric structure with a floor of compacted fill and artificial turf (or exterior carpet) would be about the cheapest, generally no need for council approval of a fabric structure here but I'm not sure about the situation where you are of course.

 

 

[kaz3g]

Rwy 09/27 at YSHT is 453m. I use it for both departures and arrivals when there is anything more than a slight crosswind on the main sealed runway. No-one else uses it much because its gravel and it's got low tension power lines at one end, an earth mound at the other.

 

Kaz

 

 

[facthunter]

Regarding the floor, gravel with carpet does work but you need to reduce dust if you are serious. IF the floor has been compacted rolled bitumen is considerably cheaper than concrete and can be repaired. Nev

 

 

[Dafydd Llewellyn]

Looking at airstrip on pretty hilly farmHeight would be 3200 0ft

Length runway is what I'm trying to work out for J200 or maybe C172/180.

 

Jabiru spec says need 645m which seems excessive.

 

Best I can get is around 450 m of strip. is it enough?

 

Next q is about hanger floor, how to do it cheaper than cement.

 

Will I need council ( or neighbour) approval for the shed or strip?

I have about 400 M @ 2000 ft AMSL. Very rough rules of thumb:

 

Take-off distance is proportional to 1/2.7th power of density ratio. (Density ratio is the ratio of the air density at the pressure altitude and temperature, to standard sea-level density.) See attached.

 

The ground roll is roughly half the tak-off distance.

 

wind and slope (especially slope) are critical.

 

Density altitude.doc

 

Density altitude.doc

 

Density altitude.doc

[frank marriott]

Gee Dafydd, I don't doubt the formula you list, but far too involved for me if I want to know DH before take off.

 

What is wrong with the common 30ft/mb and 120ft/ degree variance from ISA? At least that can be done in your head, or even easier put it on your prayer wheel. (or in many cases these days, read it off the EFIS) or have I missed something in your explanation?