Building an outback airstrip

[AshGryph]

I know this probably isn't the right type of forum to ask on, but here goes:

 

I'm doing a project for uni, which is to design an airstrip for a small community near cunnamulla (South QLD). It will primary be used for the Royal flying doctors in case of emergency. There really isnt any funding for the project so I need to figure out a really cheap solution.

 

There is already a dirt airstrip there but it hasn't been used in over 10 years. So my plan was to clean up the old airstrip, and add markings and some lighing. Also if possible resurface the strip, but that would be expensive right?

 

So basically what I'm asking is what are some innovative cheap ideas for airstrip markings and lighing? And is there a cheap way to resurface the strip, with limited resources?

 

Is there anything else I need to consider do you think?

 

Any help would be gratefully appreciated,

 

Ash

 

 

[country kid]

hey ash our local town strip was very much the same, the local farmers donated the gravel time and trucks to cart the gravel and they also suplied the graders to level it off, thats about were it stops becoming cheap but i have heard of some of the guys in the area using hard clay as when wetted down and rolled it forms a film on the surface so there is no dust and it is incredibly cheap. your only issue would be the location of the right type of clay and water? but it is a very cheap way of making a very smooth good quality airstrip.

 

Cheers CK

 

 

[winsor68]

When I was a kid the local gliding club sprayed their dirt strip with waste oil from Mount Isa Mines... it was a bit sticky until somehow it caught fire . This created a nice hard surface that lasted for years. Probably not something you would get away with for environmental reasons these days... and it did turn out later that the oil was contaminated with some really nasty stuff.

 

 

[Gibbo]

Used Oil in the high traffic parts. Needs to be burnt in.

 

Piece of railway track to drag the strip.

 

 

[pudestcon]

An option for providing a cheaper surface than the usual bitumen would be to source used (recycled) hotmix road surfacing material. You quite often see roadworks happening on highways where the machine is scabbling the ashfelt/hotmix surface away before resurfacing. This material scabbled off can be used again by spreading much the same as gravel with a grader and then rolling down in the usual road machinery fashion. It has made an extremely durable hangar apron in front of the ultralight hangar in Northam WA.

 

Pud

 

 

[Tomo]

Sounds like fun mate!

 

It looks like I could be going to PNG at the end of the yr to help build an airstrip... though mostly with hand labour...! ;)

 

 

[Guest basscheffers]

RFDS have their guidelines for strips to put the King Air and PC-12s in to, so ask them what they need!

 

 

[Guest basscheffers]

On the funding bit: RFDS are happy with gravel strips. Do you have many gravel roads maintained by the council nearby? See if the can sneak in an extra 1250 meter piece of road next time the do work! ;)

 

 

[Relfy]

It's actually pretty amazing what the RFDS can get in on.

 

Here's a couple of pics from a job I went to in the middle of nowhere. The night version of this strip is a couple of vehicles at each end facing in 45 degrees.

 

This strip was just run over with a grader and slashed occasionally.

 

I do also know being here in sunny Cunnamulla that the local council is very on-side in respect of helping important projects like this get off the ground to enhance community safety. There are lots of old quarries around the place and old sidings with gravel stored there that may? be available.

 

 

 

 

 

[FlyingVizsla]

Right up my alley - have built a few in remote Qld.

 

First - consult the ALA requirements page on the RFDS website. You're a Uni student so I'll leave that research to you. Mostly they are similar to the CASA requirement CAAP 92 (1) (1) for an unlicenced airstrip. Approach, transitional slopes, distance, width, obstacle free areas, day vs night requirements, into prevailing wind. The weights of RFDS craft are also there.

 

Next decision is how "all weather" do you want it? What materials are available nearby (CBR rating of gravel, crushed rock, quantities). Look at subgrade and geology, quarrying approvals & royalties. I know Cunamulla, so I won't be giving you any easy answers, you will have to work this out - it is an assignment after all - some effort on your part.

 

Pay attention to drainage. The strip may have to be built up to get the desired slope to shed water or you may have to build diversion drains around the airstrip area. You may have to make a decision between the cost of bullet-proof all weather and a strip that is out of action for a few days a year.

 

If your building material is of poor CBR you could consider stabilisation with either lime or flyash pozzolanic cement. Decide on the surface type. Grass is too sparse in SW Qld. Unsealed will need resheeting constantly and I know gravel is hideously expensive out there, but so is bitumen. There is a low cost seal using a black soil treatmemt which Main Roads trialled on several roads I built - this is insitu stablilisation with a tack coat, geofabric followed by a bitumen seal. Cheap and good if you can keep the water out. Looks like an unmade bed after floods and has to be ripped up and started again. Usual road building - optimum moisture, mixing, rolling to get best compaction, final trim for smooth ride.

 

Conventional bitumen seal (asphalt is far too expensive - and forget trying to use bits of bitumen left over - you'll be building for years 'cos contractors don't bring extra - you order 32K litres that's what you get). The cheapest is a double double - two seals on the same day. The 2nd precoated cover aggregate should be half the size of the first and about half bitumen. Cutter should be reduced using this method over single / single as the cutter won't have time to dissapate. Weather must be right for spray. Use a rubberised bitumen as the occasional use won't be sufficient to feed rubber into the surface and it will get brittle quicker. A bitumen seal is flexible.

 

Maintenance - grass surface needs slashing, gravel needs dragging usually with a metal frame pulled by a tractor to knock over tufts and fill in holes - watch for rocks/stones and remove, bitumen needs resealing every 7 or so years and crack & weed repairs and broom (stones destroy props and pepper the skins). Keep cattle off. Fence & grid?

 

Lighting - kero soaked dunny rolls or cotton rags in half drums (takes ages to set out and light up, also a fire hazard), battery "flares" (again setting out time, checking and replacing batteries usually 9v), solar powered "all ways on at night" lights (see SeaLight, Avlight AV70's - I did a couple of strips for about $20k - $25k - last 20 years, replace batteries 3-5 years), PAL lighting (very expensive, standby power, mains power underground, radio shack etc). Car headlights are a desperate life or death option only. Lit wind sock - can also be solar powered.

 

Furniture - gables, cones or tyres painted white. Wind sock, black circle under (old cover agg or bitumen). White signal signs. No need for line marking, piano keys or runway numbers. RFDS appreciate turning nodes at each end of the strip and a hardstand area where they can start up without throwing up stones and ambulance/vehicle can park and off load patients.

 

You'll never get out of it for free unless everything is donated. Remember there are some grant moneys available from the Commonwealth for regional airstrips and Council may come to the party particularly with gravel sources, plant hire, bitumen and the locals can do chook raffles.

 

Sue "airstrips while you wait"

 

 

[AshGryph]

Wow thanks a lot for all the awesome replies! Really got me thinking more :). Anyone heard of using old conveyor belts from mine shafts or paper mills, which I heard are about 5m x 30m or something, and collect them up and use them for the actual strip? Only reason this sounds good is it would provide a solid surface which wouldn't require much maintenance. Guess the main issue is trying to find enough of them.

 

Thanks again, Ash

 

 

[FlyingVizsla]

The world revolves around RISK. In the case of old belts or pallets, or other materials - if they are unproven you are not likely to get RFDS to be the guinea pigs. They were legendary for landing on anything, but now have to be careful because the aircraft cost $millions now. Your biggest problem there is securely fixing them in place. The axial and shear forces at the commencement of landing roll are substantial. Look at the "skid" marks. and the prop is not far off the pavement so any deformation may cause a prop strike. Any innovative design has to be signed off before insurance will cover the risk. Usually require a CP.Eng so there is someone to roast when it all turns to mud.

 

Being a low use - emergency strip it may only get a cursory inspection in the dark before the plane arrives, not good for finding the weakening fixture or the subsiding base. and these belts are u/s for mining ops so what is wearing through? steel cross plys? Might be better using a recycled product like shredded tyres if they have worked out a way to bind and spread and done some R&D on it. You can pick up some reclaimed bitumen road where the reclaimer has munched up the bitumen surface into a gravel like product but you still need to bind it to stop it flying around in the prop wash damaging the plane. There have been some innovative solutions using local materials - Torres Strait used crushed coral - pretty unenvironmental now but it worked.

 

 

[Guest Howard Hughes]

The section I work for (not Queensland), requires at least 900 meters usable to be considered for operations, in particular at night.

 

Night landings can be done via flares usually provided by the local SES, landing by car headlight is usually done only as a last resort and is becoming less common, eventually insurance companies will say no more. The government has recently been giving grants to local communities for the installation of solar powered lighting, this may be worth looking in to.

 

Finally to test the suitability of the strip, you need to be able to drive a ute comfortably along it at 100kmh!:ah_oh:

 

PS: A graded dirt strip is fine!

 

 

[FlyingVizsla]

I guess he's doing one of those "problem solving" subjects so beloved of Uni Engineering degrees now-a-days. Trying to get kids thinking "out of the box" rather than just regurgitating conventional techniques and considering all the other gear around it. Key words are "cheap" "no funding". Great idea but it seems at the expense of practical engineering. But then, when I did Engineering we seemed to spend a LOT of time doing maths we would never use again. The practical started when you got a job.

 

Any cleared, smooth reasonabily solid (no bull dust patches) bit of dirt would suffice for a landing, but once you start considering it as the town's life line for heavy expensive aircraft there's a whole new set of rules. IE isolated during floods - has to be above water, servicable and with access to the town. I have fought with townies wanting the strip relocated to "over the creek" who don't understand that the 1 in 10 yr flood means they can't get to the strip and supplies can't get to them and the 1 in 100 yr means they will be sitting on their roof rather than safe and dry at the strip awaiting evacuation to the rellies.

 

RFDS aircraft are getting more expensive and naturally they want to make the best use of the donated dollar and not unnecessarily risk aircraft. I would hate to be in their shoes, balancing need against risk. They (or their insurance company) have been known to sue for damage to aircraft caused by wildlife and stump/rock/surface caused damage. It forces Councils to maintain their non-income producing airstrip.

 

Sue

 

 

[FlyingVizsla]

Bloody hell Sue,Great post, nice contribution, I was so impressed I copied and saved it, thanks ... you did half his assignment.

David

If you want the info on building an unlicenced conventional airstrip let me know and I will get it together for you. I was intentionally vague so he had to do some of his own research. If he just quoted my stuff his lecturer will be using the red biro - it needs referencing and justification.

 

We are looking at buying and building our own airstrip in the near future. An airpark or near an existing town airstrip would be a solution but the better-half does not want to be beholden to any bureaucracy that could curtail or regulate his flying. Besides that we need soooo many hangars.

 

Sue "bespoke airstrips to the landed gentry"

 

 

[Tomo]

Bit off topic I guess, but thought some of you might be interested in seeing some of these... Got a friend that flew in PNG for 20 odd yrs for MAF, makes you appreciate living in Aus!

 

On approach to Kumbareta -

 

 

Lumusa airstrip -

 

 

Bank strip in the Jimi valley -

 

 

On approach to Bank strip -

 

 

 

[Spin]

Geez, there's a wealth of info in this place, excellent posts there Sue. Something I haven't seen mentioned with regard to lighting is a product I saw trialed in Africa, using flexible reflective strips on either side of the runway, almost like big road markers. The issue there was that anything not anchored into 1 ton concrete blocks would "walk" the instant you turned your back, so solar or similar was a complete waste of time. The strips were anchored into the ground, didn't have any obvious alternate use and were almost impossible to break, so tended to be left alone. I saw some deployed on a darkened airfield as an experiment and also some video of a complete installation and it seemed to me that at about the 1000m mark you were getting more light off the reflective strips than off the conventional airfield lighting (using a landing light). I have no idea how the RFDS would view this, but it is worth considering. If I remember correctly, the suggestion was to supplement the landing light with car headlights facing down the strip from the threshold.

 

 

[Spin]

Yeah Tomo, bad dog, off topic! Great photos though and might be worth starting something new, I have a few photos tucked away somewhere on a hard drive that I'll try and dig out.

 

 

[FlyingVizsla]

Reflective strips - they are used in Australia, generally on cones - but CASA don't approve of them and want supplemental lighting. I was being pressured by a Rural Health group to put them on one strip I was building because they thought it would be a cheap and suitable solution for NVFR.

 

Basically they fail because lighting must be visable from about 5(? have to check) NM out. Reflective strips only work when there is a light directly on them. The other issues are when landing small aircraft, landing lights illuminate the area directly in front. The lights about 30m apart need a wide splay to reflect back. We toyed with ideas for car headlights stationed along the outer premieter at 45 degree angles to light the strips to allow a take-off, but it would not allow a landing. RFDS were not keen either, especially as the alternative was solar flares - I did a deal with a nearby mine (its the safety of YOUR guys here, you're the biggest users, how about some community support?) and got them to foot the bill for the lights. I personally did the install - they came security bolted on rubber mats which were tent pegged to the ground which was hard enough to bend the pegs. Didn't stop the slasher driver turning a number into splinters and I lost 4 to theft - mainly the red/greens - my theory is they are mounted on a mobile grain bin so the harvester can find it during dark all night ops. I threatened to do a night flight during harvest to see if I could spot them. One white was stolen by a guy living rough in the bush for lighting. When all was forgiven in town he came back.

 

Sue

 

 

[Spin]

Sue, I can just imagine a bit of Aussie bush justice being meted out to the culprits. The discussion has caused the memory vault to creak open and I remembered hearing that the African experiment I witnessed was a case of reinventing the wheel - Canada having long used a similar system. Google directed me to the old wrinkled plum where I found the following post. Sounds like something that I would consider on a private strip for "just in case".

 

From pprune:

 

These have been in use in Canada for some years, complete with all necessary approvals, standards and references from Transport Canada. They would seem to be ideal for the many aerodromes in Africa that are not on mains electricity, for back-up, or as a portable system for emergency use or where theft is a problem.

 

 

 

According to A.I.P. Canada AGA 7.3 Minimum Night Lighting Requirements at Aerodromes, retroreflective markers may be substituted for lights to mark the landing and take-off areas at aerodromes provided alignment lights are installed. This alternative for night marking of landing areas, however, is not approved for certified sites.

 

 

 

AGA 7.20 Retroreflective Markers is the main section dealing with this topic. It states that they are approved for use on runways at registered aerodromes only; however they may be used as a substitute for edge lighting on taxiways and apron areas at some certified airports. Retroreflective markers are to be positioned in the same manner as runway lighting described in earlier paragraphs of this chapter. Therefore, when the aircraft is lined up on final approach, retroreflective markers will provide the pilot with the same visual presentation as normal runway lighting. A fixed white light or strobe light shall be installed at each end of the runway to assist pilots in locating the aerodrome and aligning the aircraft with the runway. Similarly, retroreflective markers at heliports are to be positioned in the same pattern as prescribed for helipad edge lighting. It mentions amongst other items, that the approved standard for retroreflective markers requires that they be capable of reflecting the aircraft landing lights so that they are visible from a distance of two nautical miles.

 

 

 

The only part requiring any power, which could be from a couple of car or other suitable batteries, would be the two alignment lights. Canada does not suffer from the theft problem that is endemic in Africa so it is normal in Canada for the installation to be permanent, including the alignment lights. However, there seems to be no reason why the system components should not be easily adapted to provide a portable installation, one that could easily be carried in a medevac plane for emergency use.

 

 

 

As mentioned, this has all been in place and in use in Canada for some years. The relevant A.I.P Canada pages date from 2001 or earlier. I am not even sure that it was invented in or first implemented in Canada. There is no way to know how many installations are in use. Transport Canada relies on the operators of registered aerodromes to provide information on their facilities for inclusion in the Canada Flight Supplement. There could be many aerodromes mentioned in the CFS for which no lighting details are provided but which actually have retroreflective markers available. On the other hand, most aerodromes in Canada requiring night lighting, including farm strips and hunting and fishing lodges, have for years had full electric systems, often with ARCAL, so the scope for retroreflective markers would be limited to new aerodromes over the past few years and those which over the same time frame have decided to upgrade their aerodrome for night use.

 

 

 

Let’s look at a few installations. These are from a two year old copy of the CFS. They were probably in use for some time before this:

 

 

 

CPT2 Killarney ON, operated by the Township of Rutherford & George Island. This has retroreflective markers for the runway, taxiway and apron. ARCAL activates the runway alignment strobes (5 clicks on, 7 clicks off). I wondered why the OFF facility as most ARCAL installations turn off automatically after 15 minutes. Surely it would not save that much electricity? After some thought it occurred to me that this would permit very bright strobes, which could identify the airport from a considerable distance, amongst a lot of other lights or in poor visibility, but which the pilot could turn off as soon as he was properly aligned with the runway to avoid being dazzled by the strobes on short final. Good thinking by someone! An ARCAL receiver/switch could be incorporated with a strobe and battery in a portable version if required.

 

 

 

CKG2 Riverton MB, operated by the Town of Riverton. This has retroreflective markers for rwys 17 and 35. The note advises that it has ARCAL Type J to operate strobe guide for rwy 35. This is rather odd, perhaps a misprint. Both strobes should operate and there seems to be no reason why the runway should not be used in both directions, especially as it specifies that the markers are for both directions!

 

 

 

CPE9 Armstrong ON (Heli), operated by Ontario Ministry of Natural Resources/Ontario Ministry of Health. This heliport relies solely on retroreflective markers.

 

 

 

CYSQ Atlin BC and CEJ4 Claresholm Indus AB both have electric lights for their runways with ARCAL Type K but use retroreflective markers for the taxiways and aprons. Similarly CAT6 Campbell River (Campbell River & Dist Gen Hosp) BC (Heli) uses retroreflective markers to outline the helipad but also has high level flood lights. Interestingly, a large certified airport with a 10,000’ main runway, CYYB North Bay ON, uses retroreflective markers for Apron 3 and Apron 4.

 

 

 

It is preferable to have someone on the ground when a plane is arriving or departing to ensure that there is no danger to the aircraft from animals, and in Africa also from pedestrians, cyclists or other vehicles. This person could turn the alignment lights or and off as required and help with setting out or collecting a portable system if that is also needed. According to the CFS, Riverton has unicom for limited hours but Killarney is unattended. The latter surprises me. I have never been there but presume that it is either near to or is the aerodrome for Killarney Provincial Park, in which case there is a good chance of deer and other wildlife being on the airfield. Colliding with a moose would be a sad way to end one’s flight! This peril exists even at major airports. I well remember a light twin being severely damaged some years ago in a collision with a deer at CYYZ Toronto/Lester B. Pearson Intl ON.

 

 

 

The runway alignment lights should remain on for a minimum of five minutes after a plane departs in case it has to return for an emergency landing. Statistically, the most likely time for an engine problem is at the first change of power after take-off. If a problem develops soon after take-off the pilot may need to immediately be able to identify and return to his departure airfield if possible. If after five minutes the ground helper can no longer hear the aircraft or see its lights then it should be safe to turn off the alignment lights and if needed start packing up a portable system.

 

 

[Yenn]

The above posts have covered a lot of ground. My only suggestion is using old conveyor belting for markers

 

 

[AshGryph]

Really appreciate all the posts :thumb_up:, you guys have been awesome, didn't expect this much info. Was wanting to put a surface of clay on the strip, but it seems too hard/expensive to source that much. Do you think it would be possible to grow some sort of grass in that area of Queensland? (about 50km SE of Cunnamulla). Currently the old unused runway is just a barren strip of dirt i think.. Seems like a very dry area, is there a type of grass that you think could be used there? This seems like a cheaper solution, and once the roots take hold it would be a good hard surface.

 

Thanks again,

 

Ash

 

 

[Guest Wigg]

Ash my 2c worth try your local garden supply people. We went to ours when builing our house, they had mixed a blend of their own grass for drought hardy conditions. We 14 years later still have the same lawn down & it still comes up great each year even with the drought. All the neighbours grass dies off ours still green within reason. Don't know if this helps or not. Sue (Wigg)

 

 

[Relfy]

Ash, living out here and growing a mighty fine lawn (complements of very generous water usage rules), I can advise that you will have extreme difficulties in growing anything that will last without a good supply of regular water. Also, unless you have a large roo/rabbit proof fence, when everything else around the strip dies in the extreme summer heat, the roos/rabbits/wallabies/ferral pigs etc will gather en mass and eat your hard work down to the roots. You will also have the equivalent of landing in the grandstands of the MCG on a sunday afternoon!

 

The summer heat is just too extreme without continuous water out this way. I believe there is a strip down near where you talk of that uses a gravel of sorts, commissioned and built by the the then successful Eddie Groves or ABC childcare fame. It might be worth having a look at what he did.

 

 

[eightyknots]

Bit off topic I guess, but thought some of you might be interested in seeing some of these... Got a friend that flew in PNG for 20 odd yrs for MAF, makes you appreciate living in Aus!

Those MAF people are truly an amazing, dedicated bunch of aviators!