Helium Ballon

I was sitting in my garden yesterday and spotted in the sky I thought its a UAP or UFO. Being interested in Ufology I got my binoculars and focused up on the UFO, disappointing it was a helium balloon, a six or a nine rising quite rapidly towards the clouds. Living on a flight path , planes from all directions high up and lower, Luton Airport and Stansted I thought how dangerous these balloons can be if they entered the engine. Would it be pulled in or would the force of the air displacement push the balloon away ?. How high would a helium party balloon achieve before it would burst, as it reached very high clouds.

Bob    Spelling of the title incorrectly, sorry.

Edited By BOB BLACKSHAW on 15/08/2022 07:26:44

Helium party balloons are said to go up about 10km before bursting -- ie 32,000 foot altitude. Cruising level for many airliners. Surprising.

I imagine they could possibly get sucked into a jet engine approaching it at hundreds of km per hour. End result I have no idea. And would rather not be on the plane to find out! Possibly trivial as the rubber is light and would melt in short order. Or possibly enough to upset the whole finely balanced and rapidly spinning applecart.

I am sure some of our aviation guys will know.

Edited By Hopper on 15/08/2022 08:04:36

The engines pull in air so if the balloon was in the correct position it would not be blown out of the way. The biggest problem is that usually it is just going to be litter somewhere, along with all the balloons from commemorative or charity balloon releases and the debris from chinese lanterns which also happen to be a fire risk. It is also a waste of the finite supply of helium that is needed for MRI scanners.

Martin C

I find at least 2 a year on my 50 acres of fields so hate to guess how many are released annually.

I suppose modern jets are designed to be somewhat resistant to bird strikes by smaller birds so would survive a balloon. But a balloon might be a hazard for smaller piston engine planes if it got sucked into the intake as happened here CRASH

A party ballon is unlikely to damage a jet engine directly. There is the remote possibility of indirect effects. Such as blocking a EPR (engine pressure ratio) probe resulting in incorrect thrust indication. Even more remote some palstics can cause corrosion issues. Specifically PVC due to the chlorine content. There have been cases of blade failure from corrosion caused by smears of plastic packaging on the surface. This was due to someone pushing the blade through the bag rather than cutting the bag open.

There was a case in the UK a few years ago of a light aircraft having engine failure from a rubber ballon getting into the air intake No not all aircraft engines have intake filters. The aircraft was deliberately trying to hit the ballons as pat of a competion.....

Robert G8RPI

A Darwin Award competition?

It's a curious element

any helium released into the atmosphere floats into outer space and is lost forever

A normal helium filled party type balloon is made from Mylar foil and could well be sucked into a jet engine. If it hit the fan blades, it would probably merely be chopped up and spat it. However, the real danger lies if it is sucked into the core of the engine, when parts could melt and block vital cooling holes in the turbine section, which could lead to blade failure.

G.

The NTSB report for the Hopper's accident can be read here. (LAX94FA047, event occurred 11/15/1993 in Brea, California) It says:

"The National Transportation Safety Board determines the probable cause(s) of this accident to be:
THE PILOT'S CHOICE OF AN INADEQUATE CRUISE ALTITUDE OVER ROLLING HILL
TERRAIN WHICH RESULTED IN AN IN-FLIGHT COLLISION WITH HELIUM BALLOONS
AND AN IN-FLIGHT LOSS OF CONTROL FOR UNDETERMINED REASONS. A FACTOR IN
THE ACCIDENT WAS THE PILOT'S INADEQUATE VISUAL OUTLOOK."

It appears the pilot perhaps with an eyesight problem and definitely flying too low for the terrain flew into a bunch of Helium balloons and power-dived vertically into the ground with both engines running on high-power.

Possibly something like when my daughter crashed my car (not hers!). Driving along an empty dual carriage-way in twilight at 70mph, something big and black, reared up and ran under the bonnet. She braked and swerved to avoid it and hit a post causing considerable damage, but no injuries. Collecting the wreck I found an empty bin-liner in the debris; my guess is it was inflated by a gust of wind and blown into her side vision causing her to lose control after instinctively jerking the steering and braking hard. As a learner driver I remember being told to run over animals in the road rather than swerve to avoid them. The advice is probably good for the UK where most animals likely to be in the road are small, but may not be smart if the animal is a Moose or Kangaroo!

Judging by the NTSB reports Helium balloons are completely insignificant compared with small private aircraft. One accident in 1993 compared with about 4 per day in the US. Small private aircraft have a relatively high accident rate mostly because of pilot error, but also poor maintenance. Compared with commercial flight, private pilots take higher risks because they're poorly supported by training, instrumentation, and safety systems. The good news is that accidents are far more likely to kill or injure the pilot and passengers than anyone on the ground.

The accident reports make interesting reading because they almost always have an accident chain where a series of small non-critical misadventures add up to a catastrophic failure.

Not suggesting there's a particular problem with light aircraft; motor-bikes, push-bikes, marathon running, horse riding, travelling by road, and living in a city centre are also risky. DIY is quite dangerous too, yet Model Engineering rarely causes accidents. I think it's because lathes, band-saws and mills are fixed and the operator rarely gets too close. Much easier to lose control of a hand power-tool and whack one's fingers with a hammer!

Dave

Edited By SillyOldDuffer on 15/08/2022 10:45:27

I seem to remember that jet engines were tested by firing frozen chickens into the intake?

Alan

I;ll bet that defrosted them rather well!

A slug of helium passing through a jet engine could be interesting, but only to an aerothermal engineer. Helium and air are both perfect gases at these temperatures but there are differences, helium is considerably less dense and only has one atom per "molecule" compared with two per molecule for air.

Ignoring the plastic of the balloon the two very much worsed case scenarios are:

1. The compressor would surge since it would have not been designed with helium in mind. Modern engines would recover from this immediately and surges are generally not a problem.
2. Combustion may cease. A relight could accomplished immediately.

These actually happening are very remote (as said above only strange engineers would be interested).

As mentioned in earlier postings such casual use of helium should be very heavily discourged. As for leaving naked flames, Chinese lanterns for example, unattended, that is just "criminal" behaviour.

JA

The industry has hundreds of chicken jokes but they are off topic.

Edited By JA on 15/08/2022 11:39:50

That is exactly the case with many accidents in industry too, including boilers. Faulty low water cut-off switch is disabled so that it stops putting the fire out unnecessarily. The factory Plant Engineer is demanding steam and now! Disabled switch is not repaired yet because the electrician says parts are not available until next week. But in the meantime the operator can rely on the gauge glass and separate low-water alarm switch that operates a loud horn. Factory has steam. All good!

The small wet-steam turbine driving the feedwater pump trips and stops due to speed governor worn out and a bit temperamental due to lack of maintenance over 20 years. It does this from time to time and you just stick a Brasso tin under the governor linkage and restart it before the water level drops too far. Boiler has water. All good!

But this time, the water level drops and sets off the low water alarm horn. The boiler operator is outside refilling the large chemical tank in the boiler feedwater treatment plant and backflushing the filters with very noisy pumps running right next to him, due to bearing wear. Does not hear the boiler alarm horn. Water continues to drop in the boiler inside. Disabled cut-out switch does not douse the gas fire. Water drops below top tube level. Fire continues to burn.

Tubes sag. Tubes leak. Steam goes everywhere. Boiler operator returns and sees and hears this. Looks at glass. Empty. Starts standby electric feedwater pump. Pumps cold(er) water into boiler. It hits overheated tubes. Thermal shock occurs. Tubes fracture at ends where stress is highest where they were expanded into the tube sheet in manufacture. Several were over-rolled and a bit thin. One has gouges in it where the expanding roller got stuck. Others, and the tube sheet itself, have 20 years of corrosion around that area, due to the water treatment plant is always on the blink and water chemistry is very often wrong and thus corrosive. The inspector commented on this corrosion last year but passed the boiler as safe to use.

Steam and very agitated water rush out through the fractures. Water is at about 350F at 100PSI before it exits. At atmospheric pressure it flashes off instantly into steam and expands to 1600 times its volume, taking the wall out of the boiler house.

Who is to blame?

Edited By Hopper on 15/08/2022 12:25:38

Management

That's what the union rep said.

Who is to blame?

You are! Under industrial safety legistation introduced in the late 1960s if you saw anything you considered unsafe you had to report it to your management. (No doubt someone will post that I am wrong).

One of the many consequences of this is that many firms, and industries, now have a "no blame" culture with lesson learnt logs etc. It is public, lawers and, particularly, the media who need someone to blame.

This is way off topic. You might get a chicken joke yet.

JA

It is a waste of a limited rescource to use helium for trivial things like party balloons, there are scientific uses which are much more important. Helium was named because it was detected spectroscopically in the sun before being discovered on earth.

Not a chicken joke but a true tale circa 1972 that brings that industrial safety legislation to mind

At the time I was working at our base onshore during a lull in diving activities. One morning a large lorry turns up with a considerable number of full bottles of 90/10 (90% helium) helium diving mix on it. Why they came I have no idea but was something to do with the US parent company as at that time all our diving was air based. We unloaded said bottles - slightly larger than the standard Oxygen bottle and laid them all out in the yard - must have 70 - 80 of them. Why they were loose no one knew as He02 bottles usually came in a steel cage referred to as a 'quad' usually containing '8' bottles. There they laid for several months.

One morning on another base working day the boss 'Bernie' comes out and says these bottles have got to be shipped back to the States - and they've all got to be emptied before they go!!!

I worked with another diver called 'Tony' and it could be said we did used to like a 'bit of a lark' so after the ubiquitous novelty of talking like Donald Duck was over we looked for something else. At the company next door they had one of those packaging air bag making bits of kit so we made a bag up some 10 ft long about a foot wide and filled it with the helium mix then a 20 ft long and then a 50 ft er - you know how these things go. The laughter got greater as this 50 ft sausage hovered about 5 or 6 feet above the deck (floor). At this point the guy in charge next door came to see what we are doing.

"I have some real big polythene pallet covers" you could staple together he suggested. No sooner said than done and we have this huge bag filled with helium straining at the leash sadly not enough to get any of us remotely airborne. Suddenly who ever has it lets it go and its off up gently but away with the breeze - across the river Yare to catch on someone's TV aerial and hang there being moved by the wind, the aerial bending in each direction in sympathy. Our boss Bernie fully supportive of our antics suddenly going pale and banning us from further stupidity.

The helium frittered into the atmosphere - an awful lot of moneys worth I guess - what a waste but we did have a good laugh from it

Happy days indeed

Tug

I suspect that "PILOT'S INADEQUATE VISUAL OUTLOOK" is almost certainly an implication by the investigators that the pilot's monitoring of his visual environment wasn't sufficient (in Britain the word used is Lookout), rather than that he had an eyesight problem (he was required to wear corrective glasses). Quite how they knew this is another matter - this investigation report seems particularly short for a somewhat inexplicable fatal accident, with, for example, no hint as to what height the aeroplane might have been at.

There is no mention of balloon fragments entering the engines (or any other mechanical malfunction), so this idea may have been a product of over-active journalistic imaginations in the LA Times.

Edited to remove smiley

Edited By Andy Stopford on 15/08/2022 20:24:46