Posted on 10/23/2014 5:54:34 AM PDT by Jack Hydrazine
Heres a post from the AMSAT-UK high altitude balloon blog. Its a great story about a balloon cruising at about 12km above the Earth completing its sixth circumnavigation of the planet. That post is from October 4th, and two weeks later the balloon is still going strong. Right now its over the Baltic heading into Russia with no sign of stopping or popping any time soon.
The balloon was launched July 12, 2014 from Silverstone, UK. In the 100 days since then, this balloon has covered 144168 kilometers and has crossed its launching longitude six times. Even if this balloon werent trapped at high latitudes (including coming within 9 km of the pole), this balloon has still travelled more than three times the equatorial circumference of the Earth.
The balloon was built by [Leo Bodnar] a.k.a. [M0XER] with a self-made plastic foil envelope. The solar-powered payload weighs only 11 grams. Its an exceptional accomplishment and one that has smashed all the amateur high altitude balloon distance records we can find.
If you look at pics of the envelope you’ll see it is simply about a one or possibly two mil polyethylene bag.
They word, “foil” as they use it in the UK probably means “sheet” or “sheeting” in American English.
Have any tests been done to see what would happen if it collided with an airliner?
Not that I know of but an 11 gram mass is not going to do much to a jet traveling at 600+ mph.
But then again the odds of it happening are extremely, extremely rare. An aircraft hasn’t hit a balloon yet, AFAIK.
A few years ago I did read of an incident in which an amateur balloon did hit a car after the balloon burst and it descended down on its parachute. The payload landed on either a state highway or an interstate while the cars were traveling at highway speeds. IIRC, it did crack the windshield but did not go through it. The payload was about two or three pounds and the payload container was made out of Styrofoam.
The payload was recovered and the owner of the payload paid for the owner to have the glass replaced.
One reason a collision hasn’t happened is the launches are coordinated with local air traffic control. Here’s an article on the subject.
http://weatherjackwilliams.com/answers-weather-balloons-and-airplanes/
Those are National Weather Service balloons. They are launch every day at 0000Z and 1200Z GMT.
The FAA regs under FAR 101 (14 CFR Part 101; covers moored balloons, kites, unmanned rockets, and unmanned balloons) state that you do not need a waiver from the FAA to fly a balloon as long as abides by these weight rules:
(4) Except as provided for in 101.7, any unmanned free balloon
that-
(i) Carries a payload package that weighs more than four pounds and
has a weight/size ratio of more than three ounces per square inch
on any surface of the package, determined by dividing the total
weight in ounces of the payload package by the area in square
inches of its smallest surface;
(ii) Carries a payload package that weighs more than six pounds;
(iii) Carries a payload, of two or more packages, that weighs more
than 12 pounds; or
The payload is only 11 grams or 0.0242508 lbs.
Pretty interesting, the guy sure seems to have a
good approach and method.
The key to keeping the balloon flying for as long as it has is to have just the right amount of helium in it to keep the envelope from popping.
The NWS balloons are lightweight and are not regulated, yet they still coordinate with ATC voluntarily, and that’s why there hasn’t been a collision, most likely.
What happens if a balloon blocks or damages a pitot tube? An Air France jet crashed in the Atlantic a few years ago from an iced up pitot tube.
Airliners have two pitot tubes.
Are they far enough apart on all aircraft models that they wouldn’t both be blocked?
I would think the Captains two would be covered easily by a balloon but the turbulence caused by the balloon flapping would rip the plastic and free them. The FO’s probe is on the opposite side of the cockpit and the same conditions would apply.
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