Solving a Problem...

Why don't you construct an underground tunnel and park the aircrafts there?.

I thought of that.. but then you have water problems, (pumps, drain tile, etc) and a lot of concrete to pour, and automatic doors, etc.. and it gets very expensive... I was trying to keep it more affordable so 'small' airports could afford it.. or even people who have their own landing strip on a farm... so 'as simple as possible'.

actually, considering the water issue of an underground park was what led me to the under water idea. (Altshuller essentially says to take the thing that bothers you, and use it to solve the problem.)

thank you

Chris

How about you pool without water? It can have just a concrete roof otherwise everything remains same including ramp, flat cars, the works.

that was my first thought.. but then I thought.. it will fill with rain water, and seepage water... so then you have to have weeping tile, sump pumps, etc... so I thought.. why not make the water my friend..

but perhaps the pumps etc, are the same price as the rail car... so maybe.

ziplocking and drowning airplanes does seem to offend people's sensibilities. I dunno why?

Not too many proper tie-downs fail. But proper ones are fairly scant. A lot are just blocks of concrete sitting on the ground - "adjustable" for wing span and parking density.

Of course you only need one loose aircraft and many can be damaged.

However, there may well be scope for a 'swing mooring' approach - think boats.

Over to you to invent it, and do an 'incentive deal' with insurers to make it 'affordable'.

Perhaps the big problem with the wrap and sink is; they will float quite well. So you might be looking at boat solutions anyway

perhaps even with my idea, the aircraft can be strapped down after bagging. This prevents being blown about, as well as ancillary damage from stuff flying around (ie 2x4's and cars)

but you are right, they may not sink very well.. especially float planes.

as to the swing solution... there is still very rapid direction changes that can damage them, as well as flying debris.

underground is best I think.. but expensive to bunkerize.

I would rather 'dry out' a sunken airplane, than to lose it entirely (much cheaper), so just drowning them was my first thought (about pools) but then the ziploc idea came to me.

chris

Tie me down any day but don't sink me

Tie me kangaroo down? is that a Ky line from some were.

Regards JD.

I just wanted to throw some ideas together to save such luverly creatures as that.

Chris;

Instead of sinking the things just put them on elevators and drop them below ground level; it can't be that much more expensive than sinking them.

OR

Build earthen sloped berms with slanted doors. If ya can afford to buy a $200,000 airplane what's another small percentage for a storm shelter?

No wait!!! How about this one -

Perhaps an airplane could survive a lower scale tornado by putting it on a rotating stand - Tie the nose and wings down at several points, have the wing tie down cables connected to a master pivot cable that would provide torque to a rotating center stand so that equal force is maintained on each wing by automatically varying yaw. Have an automated system of controlling the angle of attack by putting a force variable cable connected to the tail section perpendicular to the relative air. I think tornado winds are mostly horizontal relative to the ground.

As the storm passed over the tail section would act like a wind vane while keeping the aircraft in minimum force pitch while the wing cables maintained optimum yaw angle.

The force variable cable attached to the tail section would maintain an effective wing angle of attack of 0. In combination this might work to keep it wheels down with the wings on for lower scale tornadic winds.

Now all that would be needed is a bullet proof vest for airplanes.

Gavilan

"Instead of sinking the things just put them on elevators and drop them below ground level; it can't be that much more expensive than sinking them."

I thought of that too.. but then thought 'expensive'. I also thought of a 'Silo' with elevators.. concrete of course... but again.. expensive at that scale.. as they would have to be 40' feet diameter I think.

as to 'swing' solutions.. it may well work, and be affordable, but it doesn't protect them from flying debris. (bullet proof vests for sure!)

thank you

Chris

Chainsaw the wings off the suckers, that'll stop 'em blowing about.
Del

Like this? Oklahoma boat harbor after tornado.

Someone has chopped the wings of them boats.
Del

I'm actually thinking 'submarine'.. so this is above surface level, and subject to flying debris and max surface area to engage the wind... not so good.

we need to minimize the 'surface area' that the wind can grab.. so even throwing a big tarp over them all, and staking down the edges thoroughly, would help some.

cheers,

Chris

Perhaps just fly them elsewhere.

now why didn't I think of that...

or... don't fly when there is a tornado coming... come to canada.. no tornadoes in the winter!

I was thinking the same thing.

If the owners have time to move and bag them, wouldn't they have time to fly them elsewhere.

But then, I don't think plane owners are that easier to get a hold of during a tornado alert.

I like your idea of drowning the little suckers. Because they don't need to be flown, only moved.

FT

... illustrates a disadvantage of fixed moorings

_{(just finishing the comment for you)}

If they would have bagged them and sunk'em when they saw the storm comming it may have been different..Ever try to sink a closed plastic bag.. Most Okies Know when to let go and find a hole, wet or dry for themselves..The Stronger structures seems to be on target.

Marinas in the Galveston area looked worse than this. There is no explaining the damage that is done.

Not too many ways to effectively protect aircraft from a tornado (especially a F3 or larger), unless you stuff them into a purposely-built hardened aircraft shelter, much like what NATO (incl. the USAF and Canadian Armed Forces) have built for their fighter aircraft. Dunno about Russian and former Warsaw Pact aircraft shelters. Also, even military-grade a/c tie-downs set in concrete will not effectively hold down an aircraft.

Regular a/c hangers will not withstand a direct tornado hit, as most are designed to withstand anywhere from 90 to 100 mph sustained winds....along the coast lines like FL, GA, SC, NC and the Gulf Coast this would be higher pursuant to state Building Codes, ASCE-7 Standard, and FAA standards.

If you have ever been inside one of these military hardened a/c shelters than you know what I'm talking about......built to withstand a near-miss from a nuke (a few km away), though not a direct hit....so a tornado posses not much more of a design challenge vs. a nuke. I know this to be a fact, because when I served with the USACE on several occasions we provided engineering support to both the USA (for copters and liaison a/c) and USAF (for the USAF [ie, SAC & TAC], USAFR and various state ANG units) for airfield and appurtenant facilities design....including aircraft hardened shelters. And, during my civilian engineering career I've done a whole lot of aviation facilities design, including several "International" airports in the NE.

Problem with bagging an aircraft is having the time to do so (approaching storm/warning?) + being a daunting logistical nightmare. That's one huge plastic bag! Uhhh, a large ZipLock bag perhaps?! How on earth do you get it effectively under the landing gear without shredding it????

Hi Mark,

Yes, the ziploc bag was my idea.. 3 sided as I said.. role the plane on.. then throw the remainder over the top, and zip it up.. then suck out the air. the whole rail car would be designed for it.

I've been in the Diefenbunker near ottawa, which was designed for a near miss.. (actually it has a scene in the movie "Sum of all Fears")

cheers,

Chris

If you sink the aircraft without filling it with water it will be crushed and probably look as bad as if the tornado got it......

I agree with 34.5... about the loads to sink the craft would stress it excessively..but I don't agree with 'crush'... based on what that word means to me; that the water pressure vs air pressure would damage the plane..

do you have any calculations to back up your belief?

thanks,

chris

Hi Chris

No I don't have any hard data for the differential pressure the planes can stand up to, but of necessity they are built light and have only a thin skin and the normal pressure differential is limited to allow for sudden gusts and turbulence. If you consider the pressure one meter below the surface is 1/10th atmospheric I think you get my drift.

I get it.

perhaps the solution really is more about creating affordable accessible (and safe) hangars...

cheers

Hi Lyn,

I answered/made suggestions for most of these questions in the OP.

I wanted to hear your suggestions just as much as mine.

first.. it was trying to solve the problem for 'fly-in' events. (assuming most owners had some sort of solution for their aircraft at their home airport.. ie. a hangar)

so a fly-in has all hands on deck, ready to help, when the storm is coming... no need to call anyone.

secondly, if the rail car is used as a taxiway, all the aircraft are already on it. they would simply lay out a bag, roll the plane onto it, zip it, strap it down, and all the craft go under at the same, time, and come out at the same time.

water is cheap, bags are cheap, dugout (lined) pits are relatively cheap.. leaving just the rail car as fairly expensive.. and maybe there are better/cheaper solutions for that part.

this was supposed to be a communal exercise in problem solving....

and putting the plane under something gets it out of harms way... water is cheap (especially in florida), and survivable... even if you don't have time to bag them. (you would have to spend some time de-waterlogging.. but still much cheaper than wreckage.

cheers,

Chris

OK.

so... another above-ground solution, is to erect concrete walls between the parking spots, and attach bottom hinged steel doors. If the aircraft is already parked in such a rentable spot, at a fly-in meet, then in the event of a storm, all that has to be done is tie down the aircraft (equipment provided with the walls) and raise the steel doors.

As the wind is primarily horizontal, this plan will protect the planes from most debris, and the tie-downs will resist the suction forces of the wind, which is less than full force, due to the walls.

still expensive though...

chris

Why not put a roof on?

_{I still think the swing mooring is worth a look}

just to keep costs down... and the roof may get ripped off, and become damaging to the plane.. but if it was membrane over steel frame, it might work fine.. although subject to wind damage also... but will help keep rain out... prevent flooding.

If the airport is in tornado alley.. it might be better without a roof.

What did you have in mind more specifically for the swing mooring.. a lazy susan? please describe or _{^{(god forbid)}} draw a picture.

I suggest you go simulate your protection first in the wind tunnel. I have a bad feeling, your planes might get flown away. If strong winds gushing through the "mebrane protection"-(yah, whatever it is called), upper part(without the roof) will be at low pressure. The wind will be sucking out your precious planes. Ending...flying planes without pilots

I'm not a huge fan of the membrane roof.. and I definitely understand that the planes will still have to be tied down.. the roof may protect from damage.. or not...

I'd be pretty sure that the membrane would get blown away.. but perhaps it should permit the membrane to release at a designed wind load.. but leave the frame intact.

cheers

chris

Gavilan got it 5

Read the bit after "No wait!"

But all you need is an 'A' frame that picks up the tricycle and has wheels that let is slew around a 'ground spike' pivot point.

Bear in mind most small aircraft fly happily in this sort of wind speed.

VNE is usually much higher, (170 kn) or above maximum hurricane speeds.

A link

yes.. the speed is normal.. but the shears and changes is what will hurt them. but it is a reasonable idea. a simple tube frame - roll-on, roll off frame.. with casters essentially, if I am understanding you.. and of course a pivot.

chris

membrane roofing..just for you!

Little ones. I think I'd rather build those than freight cars, digging and filling a canal with water, and making giant zip lock baggies.

I see the benefit of that design.. thank you...

now if only airplanes had a reverse gear...

Some do!!!!

Some aircraft with variable pitch props can actually back up, athough reverse pitch is mainly intended to be used to slow down on landing. Problem is that I don't believe insurance would cover any incidents involving backing into a hanger!

Hooker

Nomads can

Del, Itook away one of your Off Topic points. I agree with you, the idea is bonkers.

Either build a quality hanger, have the aircraft well insured, and try to be able to fly out of the airport well before the storm.

K.I.S.S.

God love ya for swinging for the fence, but the difference between threatening weather that passes through and twisted scrap is unpredictable and measured in minutes.

agreed... how many minutes?

As much forewarning as the radar provides.

You can be under a tornado watch without ever having a tornado, or one can drop down on you with virtually no warning. 0 to 30 minutes.

Just wanted to point out that the Sun N Fun fly-in takes place in Florida. If you build any kind of canal or man-made body of water in Florida (assuming the EPA would let you) you can be sure that within a month it will be populated with 'gators.

we can ziploc the gators too!

And Noles?

Inexpensive and tough. Good old fashioned airplane sized quonset huts. Bolt them to the tarmac, and the small airports could charge a small monthly rental fee to recoup the money.

oh sure....

thats true.... but then you need cranes and slings and big pillows... and then there is still the problem of airborne debris.

how's the squirrel apple shredder coming?

Instead of sucking the air out (of the plastic bags) why not blow them up, each one
into a pressurised "balloon"? The balloons to be close chained down to the ground,
so that although they can move a little, the movement will not damage the contents,
nor allow any parts to "fly" off preventing damage to other property.

Similarly, any other flying parts should (in theory) just bounce off the balloons and
not damage the plane / boat / contents whatever. Alternatively:

If you want to follow the money, very cheap "Nissan" huts could be used. (per RAF)
in bulk these are very cost effective, easy to erect, and rent-able!

Further, these could be subsidised, or made compulsory, by the insurance companies.

Think I will buy shares in a balloon firm, or corrugated sheet maker. Royalties?

jt.

A man was telling his neighbor, "I just bought a new hearing aid.
It cost me four thousand dollars, but it's state of the art.. It's perfect."
'Really,' answered the neighbour. "What kind is it?"
"Twelve thirty.."

just as reasonable as drowning them.. tethering is the critical thing. thank you. very imaginitive.

thank you for the humour...

Chris

You really have only two options to successfully protect small aircraft fro tornadoes:

1. You can build a series of reinforced concrete shelter with cast-in-place walls and floor slab and top it off with prestressed concrete roof panels and integrally cast-in-place reinforced topping slab. After the concrete has fully cured you would place an earthen mound around and atop each shelter bay. Of course this is an expensive option.

or,

2. Construct 3rd Generation Arch Panel steel lined Hardened Aircraft Shelters (HAS) or Protective Aircraft Shelter (PAS), like those manufactured by American Shelter Technologies that are approved by the USAF and the remainder of NATO:

http://www.americansheltertechnologies.com

An USAF operated HAS manufacture AST with F-15C Eagle inside:

Here's a standard NATO HAS in Belgium:

Here's a NATO HAS w/ a F-16 Fighting Falcon inside:

Here's a pic showing the inside end corner of an USAF HAS; notice the steel arch lining.....you get the gist:

Of course these types of shelters are only limited to small aircraft due to construction practicalities and economics and wouldn't be feasible for larger aircraft such as WWII warbirds (B-17, B-24, Avro Lancaster, C-47, etc) and modern civilian and military transport aircraft.

Sorry about that......some of my personal pics that I tried to post wouldn't take hold....dunno why either because they're *jpeg. Bummer!

you have my hotmail... please send.

Just a few quick guesstimates on 'sinking' say a Cessna 150 sized aircraft;

Ignoring wings, say the fuselage volume is around 200 cubic feet and the mass around 1100 lbs.

It would displace 200 x 62 lbs = 12,400lbs. Meaning ~5.65 tons of ballast.

I doubt there are points on the airframe good enough to resolve that sort of 'pull down'. Which raises the problem of it being vastly over stressed and/or snapping somewhere.

-----------------------

On cyclone resistant buildings;

As you may see in this pdf - the devil is in the detail, not so much in a 'massive, heavy, vast cost, bomb proof' requirement.

Industrial sheds that are cyclone resistant (category 5) are not that uncommon or that expensive.

thank you so much for the pdf.

and the math... I release the ziploc idea to the wind.

Submerging any aircraft is not a good idea, as water can possibly enter into the fuel tanks (if there is a bad seal on the cap) and seriously contaminate the aero gasoline....not a good thing! FAA would seriously frown on any attempt to submerge an aircraft.

for sure, de-waterlogging is a problem.. but I presume cheaper than replacing the entire craft. who wants to gamble with nature? as to the FAA regarding 'on-the-ground' protection of aircraft, I didn't think they had any jurisdiction in this regard... perhaps frowning is the extent of their powers? sort of like the surgeon general and smoking.

chris

The underlying problem is the target was chosen as "Fly-In" type events, where one inherently doesn't have sufficient hangar space because you have buckets of guests.

These events typically are picked for having lots of open field space.

And except for debris, sufficient ground anchor tie downs will keep the aircraft firmly on the ground undamaged - the average small aircraft pilot however doesn't travel with 4 giant ground auger tie downs.

And once a single one gets loose...

Or the construction site 20 miles away 'donates' a truck load of 2X4s.....

Don't have to be 'giant' - and similar are often carried in 'rural' flying

But it still leaves the problem of change in wind direction.

that site gets flagged by my AV as malware...

"the average small aircraft pilot however doesn't travel with 4 giant ground auger tie downs."

perhaps they should? Perhaps 6 ground anchors pinning a huge tarp would work? (plus separate plane tethers, if the tarp blows away at a pre-set wind load. it would limite debris damage)

chris

I like your thinking outside the box but you are now in a bag. I think the biggest drawback will be having a response team ready when a tornado strikes. I have witnessed one such tornado that struck Frenchman's Bay Ontario with no warning at all (1960s). I was attending a summer course and awaiting a ride on my parents front step. There may have been a five minute warning that something nasty was about to happen. I went in the house and shut windows and water was falling as fast as a garden hose would deliver as if fully opened against the window. A water spout crossed the Bay and picked up sail boats from their moorings and tossed them on land. It was over in 5 minutes. Our house was unscathed but the street flowed like a river for 15 to 30 minutes.

I still like the bag idea but I think these bags would have to be employed when the plane is parked and the owners/response team are absent. The bags may be designed with some sort of aerodynamic features and tie downs to deflect these sudden storms. Not sure if the bags would create problems with heat and planes. Hell, Bag 'em Chriso.

Thanks for the lead on the book, I will look for it when I next order books.

thanks.

The posts are getting a bit long, but just in case it has not already been suggest the following may help.

When the plane is parked, the front pair of wheels are rolled on to a flat disk, pivoted in the middle, and the two wheels chained to the disk edge. The concept is to think of the plane as a weather cock? when the wind strikes the plane from the side with both wheels fastened down the plane should rotate on the rear wheel to face into the wind ,a position for which it was designed? Just a rough outline.

Regards JD.

GA. You hit the crux on the head. It is short term warning and the magnitude of the forces applied. All anyone needs for observation of the effect is look at a tree that has been hit and see the way it has been twisted from its trunk, amazing evidence. Even though I think the warnings are getting better, they are still short, most people are not nearby to respond or even receive the warning. Your idea of putting the planes in hardened shelters or flee the danger is practical. Fleeing the scene may be difficult as you point out and someone has to be nearby.

Thanks kevin. I thought I was the only one to be thinking this. Glad that I'm not alone.......

solid answer... not very affordable, thats all. this is an existing solution. I was hoping for solutions that don't exist... so I'm perfectly willing to listen to every single crazy idea... one never knows what will pop up. so as to 'some peeps don't get it'.. I was staying away from hard decisions.. this is a freewheeling brainstorming session... and no one knows 'everything'... so lets keep an open mind.

"Open mind?"

An image from your video

Note; it's those without that are upside down and causing the damage.

That/those BTW is likely this

In addition to the Homestead air force base, there is Homestead General Aviation Airport. All of the planes that would fit were packed into the strongest of the hangers. Not strong enough. Andrew ripped the building apart, and smashed all of the planes into one big tangle of parts. One of those planes was an old Ford Tri-motor. Some of the panels were ruined beyond repair, and are no longer available.Ten years later, I have not heard of it being returned to flying condition yet.

That storm ripped the roof off of the National Hurricane Center. If they were not well prepared, who could be?

yeah, go figure, huh?

That whole area was wiped. I got my private license through the FBO at Homestead General in 1971. When I visited sometime after Andrew I didn't recognize anything except the runways. And the mobile home park that my parents moved out of a few years before the hurricane hit was totally gone, except the swimming pool and concrete mobile home pads.

I'm afraid that I have to concur with others that cheaply protecting aircraft in the path of a tornado is an exercise in futility.

Hooker

US customs worked out of HGA. After Andrew, FLL sent a truck there to provide fire protection to the airport while repairs went on. There were three things that stick out in my mind after all these years. There were lots on avocado orchards i n the area of HGA. The branches broke off of the trees, and clogged the chain link fences. Then the wind ripped the chain link fences apart, and they were like giant tumble weeds littering the area.

There was an automotive dealership that had a concrete roof of the long tee shaped design. The wind had gotten under the end of it, and split part of the roof right off. Cracking 12 inch thick sections as it went.

Along 152 Ave, there there were tall concrete power-line poles. They were marked for use at 105 to 120 feet above ground. As far as I could see, every one was broken in half. There were seven strands of steel wire in each of the four corners. Each of the steel cables was as thick as my thumb. And there was no surface area for the wind to get hold of, like a sign, or billboard. Just the wires, and the pole.

There were no recognisable landmarks. Fire and police learned to spray paint the name, or number of the road into the road. Addresses had to be spray painted onto any buildings. Spray paint was also used to identify homes and buildings that had been searched, and marked for any hazards or worse. Grim days, and I was not damaged by the storm.