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Episode 45: Shredded Plane, Fire without matches

  • Shredding an airplane with a propeller: confirmed
  • Starting a fire
    • ...with sticks: confirmed?
    • ...with chocolate and a soda can: confirmed
    • ...with a flashlight and steel wool: confirmed
    • ...with a bullet: confirmed
    • ...with ice: confirmed

shredded plane

Shredded Plane

Myth: There is a photo of a shredded plane that made its rounds on the Internet. There were evenly spaced slices in the back half of the fuselage. There were two explanations made as to how the plane got that way. One explanaition was that a disgrunteld ex-wife went after plane with a chainsaw Another explanation was that another airplane got loose in a hanger and it's propeller did the damage.

shredded plane

Adam picked up 3 airplane half fuselages (half a fuselage was cheaper than a full one). Two would be used in the busting of the myth -- what happened to the third?

Chainsaw explanation

Jamie went after one of the fuselages with a chainsaw to test the ex-wife explanation. He easily cut through the plane and made multiple slices. They examined the cuts and decided that the edges of the cuts were too jagged in comparison to the photo.

With this particular explanation busted, they gave the green light to the grand busting of chopping up an airplane fuselage using a propeller. Jamie: "Mayhem, destruction, the whole nine yards"

Runaway airplane explanation

Myth explanation: A pilot handstarted the plane. The engine starts, but, before the pilot can get back in the plane, the plane starts to roll away into another plane, causing the neat cuts seen in the photo.

Adam and Jamie went to an airport to measure the characteristics of the plane described in the myth. What they learned from their expert:

  • a pilot might handstart a modern plane if the if electrical system went flat.
  • The idle speed of an engine is 600rpm
  • The starting speed of an engine is 1200-1500rpm
  • A plane would move forward even at 600 rpm
  • A plane can reach 30mph on ground
  • It's a very bad practice to handstart without someone behind the controls. After you handstart it you need to throttle it back to the idle speed. If someone isn't behind the wheel, the engine will be at 1500 rpm and the plane will roll away.

Jamie was unable to handstart the plane that was similar to the one described in the myth. Adam successfully handstarted a smaller plane engine.

Test setup

  • Engine: Jamie shopped for and got a 380hp airplane engine. It was a quirky engine with dirty fuel injector servos, but they finally got it working.
  • Ground speed: Adam worked out the ground speed of the plane from the gashes in the photo. Plane in the photo is punctured every 7". Based on Adam's calculations, the plane would have been travelling 29.8mph, which is well within the parameters of the myth.
  • Fuselage: They mounted one of their half fuselages onto a steel frame to simulate a full airplane.
  • Track: They decided to use railways to guide the engine and propeller into the backhalf of the fuselage. They were able to get a railroad cart from the Golden Gate Railroad Museum and there were already railroad tracks they could use at the abandoned Alameda Naval Air Station they frequently use. They cleaned up and used about 700 ft of track for the myth.
  • Weight: They used ~10,000 bags of sand to make sure that the weight of the 'planes' was realistic

The test

They did two test runs to see if they could get the engine up to speed. On the first test run, the engine wasn't rolling fast enough to replicate the myth so they activated the kill switch. The engine had a lot of leaks. On the second test run the engine got up to speed, so they were ready to test.

On the actual run the propeller went through the fuselage like butter. It was probably going too slow as the slices were too narrowly spaced, but they were satisified with the results.

shredded plane shredded plane shredded plane

confirmed

Fire without matches

Sticks

Tory and Kari had a lot of trouble getting embers with just two sticks. Grant tried using a bow to spin the stick but didn't have much luck either, though he was having some coordination issues keeping the stick spinning.

Tory: "I think we're all gonna die"

Kari tried using a powerdrill to spin the stick. She got plenty of black wood and smoke, but no embers.

Tory: "Would you call using gunpowder cheating?"

With the gunpowder the build team, at last, had fire.

There's no doubt that it's possible. Jamie claims to have done it himself in the past. In Kari's words, "We really suck at it."

Bullet starting

Myth: You can use a gun to start a fire by removing a bullet from it's casing and using the firing cap to ignite a pile of gunpowder.

They removed the bullet to just leaving the firing cap and collected gunpowder from nine bullets. They fired it into some kindling: no fire. Their explanation was that, without the bullet pressing up against the firing cap, there wasn't enough pressure to ignite the gunpowder -- it would just throw the gunpowder out.

Tory tried out black powder from old muskets that he thought would be more flammable than smokeless powder. He ignited some black powder and smokeless powder and found that the black powder was easier to ignite, but it burned faster than the smokeless powder.

Tory rigged up a new test setup using a wad of cotton and black powder stuffed down a musket barrel. He was able to fire it at some kindling and get fire.

confirmed

Chocolate + cola can

Myth: Using chocolate as a mild abrasive, you can shine the bottom of a cola can to create a polished mirror with which to start a fire.

Tory and Grant polished the bottom of their cans for six hours. Tory's can was shinier than Grant's and was able to create a hot spot on a leaf. They showed the embers smoking but no fire.

confirmed

Flashlight battery and steel wool

Myth: you can start a fire by touching steel wool to the battery contacts on a flashlight.

They got this one from a Rod Hood outdoor survival video. In the video, Rod Hood touches a steel wool to the battery contacts and it lights immediately:

The build team was able to create fire as well, but not as effortlessly as Rod Hood.

Fire from ice

Myth: You can start a fire by rubbing a block of ice into a shape of a lens and using it to focus a beam of light.

They found some good, high-quality clear ice to use from an industrial ice maker.Kari sculpted a lens shape out of the ice using a knife while Grant made his using a rock. They got smoke from Grant's lens but they couldn't get fire. As the lenses melted, the hot spot dissipated.

Tory and Grant decided to create a lens mold to cast the ice in. Industrial ice makers use pressurized air to agitate the ice to get out the bubbles. Tory and Grant used an electric massager inside a regular kitchen freezer. Their lens came out completely fogged.

Kari decided to make a large sphere of ice. As the sphere melted, it would be able to hold it lens shape longer. Kari got smoke from here sphere. They put up the confirmed sign but they never showed actual ignition.

confirmed

Comments

this was very useful source of info I used it to complete my science fair project

if you've watched man vs. wild, bear grylls actually does start fires with the stick and bow method, but he mentions that it's tiresome and can take 30+ minutes to do it. of course, you're unaware of the time passing unless he mentions it since they show him at the start, and then turn the camera off till he's finally gotten an ember.

Does anyone know the name of the song at 24 minutes through the show...

Nevermind 27 minutes and 30 seconds approx.

I have a good friend who does primitive firestarting demos. He can make a bowdrill from scratch and have a fire going in 30 min or less. I was able to in about 1hr first time with instruction. Wood from the woods, string made from waist band of t shirt and i only used a pocket knife to fabricate it all. Good to know for emergency in woods.

There are many ways to make fire without matches... you can view this fire method page for more information - http://survivaltek.com/?page_id=274

They should have used distilled water to create the lens.
For small amounts of ice it's the simplest way! The ice industry doesn't use it because it would be to expensive.

what the industrial icemakers are actually doing is keeping the surface in motion, so the ice freezes from the bottom, so air is not trapped. Normally ice freezes from the top and all sides in, trapping air bubbles in the middle. Mythbusters could have done it that way, or remove the air before freezing using a vacuum chamber, etc. However, they did show that it's pretty difficult to get a sharp enough focus without a precision ground lens. I'd have almost called it busted.