Tying the aircraft down

[Moneybox]

How much does it take to keep a small aircraft (310kg) tied down?

 

Today I braved 44°C to do a little more work on the Sportstar. We took a quick trip south that lasted 10 days and arrived home Saturday. I had to buy the brass hose tails for the new mechanical pump and when I picked up the post I got the carburettor sleeves so that just about finishes the work to be done. I'm still waiting on engine mounts but I don't think that will prevent it being passed for registration.

 

Now I have to consider the problems faced in fitting the wings at the airport and tying it down once that's done. I don't think there are any anchorage points out there so I'll have to provide my own. I have some steel for a dozer blade, one at 100kg and two at 35kg each. I think if I put an anchorage point onto each one they'd do the job? We get some really wild weather here and there are no hills, buildings or trees to break the wind.

 

Any suggestions? 

[rgmwa]

One trick I've heard about but haven't tried is to lay thick rope along the wing to break up the airflow and the lift. Sounds plausible. 

[Moneybox]

Mmmmm..... might work but I guess you'd like me to try it first? 😁

[rgmwa]

Can’t do any harm if your tiedowns are a bit dodgy. 

[Thruster88]

Cut off steel posts or star pickets work. Drill out the top hole and use a shackle for the rope.

[skippydiesel]

At "home" I have three Star Pickets driven, as far as I could, into the ground. 

 

You may need to borrow/purchase a post driver (I call it a "donger") and the Star Pickets

 

Place your aircraft where you intend to park it - mark the points where you will drive the pickets in. Remove aircraft to do the driving.

 

Drive the pickets, at an angle away from (not straight down as in fencing) the aircraft tie down location. This is the same concept as pegging a tent .

 

The tail picket is left as is, with the two wing pickets reduced (cut off) to easily clear the underside of the wings. Smooth the cut off edges, they are razor sharp & will do a lot more than bark your shin, if you inadvertently make contact. I go to the next level and put a plastic high viz cap on each picket.

 

The tail picket is perhaps .5m behind the tail ( you may go further back for your nose wheel aircraft/tail in air).

 

The two wing pickets are placed, so that the tie down straps are in front of the wing and at about 45 degrees out from the wing tie down. The concept is to remove all slack (without undue tension) on all three straps.

 

I use cam buckle load rated straps, with metal hooks at each end, purchased from Bunnings Aerospace, to do the tying down bit. You may find that the hole in the star picket will have to be enlarged to accommodate the hook. After tensioning down the strap, I use the surplus strap to go round both ends of the hook eye and tie off, as added security

 

A D shackle  or two may help with the tail tie down.

 

I carry a separate lightweight kit for temporary tying down, when on an away trip. 

[Tasmag]

The main thing to account for is what the wing can lift, not what the aircraft weighs. MTOW would be a good starting point.

 

I don't think that 170KG of steel would come close to doing the job.

 

Mike

[facthunter]

You're just toying with the problem. The plane(s) should be secure in a hangar built strong enough to  withstand any likely winds and then some. Your "Bird" IF you MUST have a tie downs do it properly. Big enough cement Blocks flush with the ground and a ring to lift and tie to. The PLANE may still be there but damaged and overstressed..  Nev

[onetrack]

Most Western Australian red dirt with moderate clay content sets like concrete in Summer. You're struggling to drive star pickets into it. I've found modified Hilti concrete bolts ("screw anchors") work for me, for anchoring items in hard W.A. ground in Summer.

 

The Hilti concrete bolts normally require an undersize hole drilled into concrete, and the bolt them screwed straight in. But that's not practical in dirt, so I grind the end of the Hilti bolt to a taper, which assists in starting them into the ground.

You drive them in with an impact wrench, and you'll need a minimum of 200mm length, probably 300mm is better. Slip a big heavy washer under the head prior to installing, and use a neat-fitting D-shackle under the washer as the anchor point.

 

/_ui/package/100336/responsive/assets/images/logo_2016_sRGB.png

HUS4-H screw anchor - Mechanical Anchors - Hilti Australia

WWW.HILTI.COM.AU

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Hilti Mechanical Anchors - HUS4-H screw anchor - High performing hexagonal head screw anchor for fastening to concrete and masonry (carbon steel)

 

[skippydiesel]

"Most Western Australian red dirt with moderate clay content sets like concrete in Summer. You're struggling to drive star pickets into it. I've found modified Hilti concrete bolts ("screw anchors") work for me, for anchoring items in hard W.A. ground in Summer."

 

Is the above system good for when the ground is soaked?😈

[skippydiesel]

Whatever system is used - Its asking for problems if the aircraft can move on its restraints. Doesn't matter how secure/heavy the anchor.

 

I often see aircraft tied with loose restraints - the wind/gusts will start to jerk/move the aircraft - once this starts, damage can be done to the aircraft.

 

The jerking may also break the straps/ropes or loosen the anchor.

 

 

[facthunter]

Do you fit Gust locks? .  Nev

[onetrack]

Whenever the ground gets soaked - a rare event in the W.A. Goldfields - you have to re-appraise your hold-down method. In which case, the star pickets will probably prove a better hold-down system. 

The ground can go from concrete-like to extremely soft once it gets soaked, and that applies anywhere.

[facthunter]

Why be there when it's soaked? Would the drome still be serviceable?  Nev

[dlegg]

4 hours ago, facthunter said:

Do you fit Gust locks? .  Nev

Mandatory or you're in for a nasty surprise 

[Bosi72]

This worked for me before got in a hangar..

[kiwiaviator]

This is a very informative publication with some great ideas for 'mooring' your aircraft to mother earth https://www.aviation.govt.nz/assets/publications/gaps/secure-your-aircraft.pdf

 

I had my Jabiru 230 tied down in Newman just up the road from you one winter. I used the Claw tiedown system. In the summer I stored it in a hanger in Geraldton as there was no way I was having it outside in wet season. You should seriously consider some sort of hanger. The container shelters are cyclone rated and cost effective. I would have permanent tie downs as well in them.

[Moneybox]

Thanks for all the great suggestions.

 

Our shire look after the airport so I had a meeting this morning with the CEO. He said that there are no anchorage points out there but suggested I take a look at the concrete blocks lying off to the side.

 

 

I have to look into who owns them. I have the hooks somewhere to fit onto these anchor points so they might do the job for now. I don't think I can drive star pickets in but I do have a thumper if I need to use it.

 

I like the look of the Ground Grabber bolts but the Hilti ones might be just as good in this ground. You never know what it's like until you actually try to drive something in. I often peg ground to claim the lease so I carry wooden and steel stakes. Sometimes I can't get a steel stake in the ground but then 50m away a stake needs to be driven deep just to remain standing. Same thing when its wet. I've been parked overnight during the rain and woke up to find the tyres a few inches down. Other ground remains rock hard.

[Moneybox]

https://peggypeg.com.au/products/peg-stop-heavy-duty-screw-peg-20-cm-p-s-hd-pack-of-4?variant=42099294011587&country=AU&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&adv_go_camid=18405330892&adv_go_groupid=&adv_go_adid=&adv_go_keyword=&adv_go_matchtype=&adv_go_proid=shopify_AU_7408015835331_42099294011587&gad_source=1&gclid=CjwKCAiA6t-6BhA3EiwAltRFGBQJVKYC_q72zkMJt9SRS0r7wCFrFshLJ7_RE4Wbbtkmxe6OOuDd4BoCDe8QAvD_BwE

 

I like the way these type of things can be removed if necessary.

 

 

Four of these are $55 but they are only 200mm long and that might not be enough in soft ground?

 

[KRviator]

23 hours ago, Thruster88 said:

Cut off steel posts or star pickets work. Drill out the top hole and use a shackle for the rope.

That's what I carry on away trips. I have 3 x 30cm star pickets with D-shackles on 'em and a mallet.

Bit heavier than I'd like, but carried as far aft as I can get 'em gives me an quarter-knot TAS increase.😃

[skippydiesel]

31 minutes ago, KRviator said:

That's what I carry on away trips. I have 3 x 30cm star pickets with D-shackles on 'em and a mallet.

Bit heavier than I'd like, but carried as far aft as I can get 'em gives me an quarter-knot TAS increase.😃

To me there is a big difference between a permanent tie down and a traveling tie down system.

• The permanent is a 12 month, all seasons/conditions structure, without weight restriction. The permeant can be very secure
• The travel system should be compact, lightweight and easy to set up/remove. The travel unit is a compromise, that is unlikly to stand up to severe wind conditions. The cautious pilot will have avoided tying down (traveling) his aircraft in this sort of weather.

I see travel systems that are reasonably compact & light weight BUT then need a good sized hammer or even cordless drill, to install - questionable advantage.

I see a lot of permanent and travel systems that use cheap string to secure the aircarft (most often slack) - this is counting pennies while dollars are potentially lost.