Does Ice Really Fall From Aircraft Like This

originally posted by: TEOTWAWKIAIFF

A katabatic wind, from the Greek word κατάβασις katabasis meaning "descending", is the technical name for a drainage wind, a wind that carries high density air from a higher elevation down a slope under the force of gravity.

Wikipedia.

That is when mountains are involved. The atmosphere can also stratify between layers.

As a plane ascends or descends through these layers ice can form. Usually, they don't grow to large sizes but it looks like they can!

Full disclosure, I was reading about Antarctica and how winds convert a solid snow flake back to water before it hits the ground (a reason why the back side of mountains can be drier than the other side). The first person to respond was like, "Duh! Any pilot can tell you this as you pass through layers of atmosphere..." which is the only reason I know about this! I looked up the stuff on Wikipedia and had it handy!

The kind of ice the OP is talking about is almost certainly not airframe ice that accumulates when an aircraft flies through icing conditions. The only aircraft flying into these conditions should have systems to prevent any significant accumulation of ice. For example, the aircraft I usually fly for a living (747-400) has deicing or antiicing systems for Pitot Tubes, Temperature Probes, Alpha (angle of attack) vane, Windows, Windshield, doors, Water and Toilet drain, some antennas engine cowlings, nose dome bullet, and inlet guide vanes- and the Wing . The systems are powered either by engine bleed air from the jet engine high pressure compressor section, or by the electric system.
The ice in question probably comes from a leaking toilet holding tank gasket. The incessant freezing and thawing is hard on the gaskets. Leaking can be discovered by looking for blue streaks down the fuselage. The tank itself is sometimes called the "honey bucket." The blue stain comes from a blue dyed quaternary ammonium compound used for deodorizing. I know, TMI.

a reply to: F4guy

It doesn't look blue in any of the images.

www.newsletter.co.uk...

a reply to: F4guy

I was relaying info I just happened to be reading along! Thanks for the details about the plane! It is always nice to learn something new.

I live in Alaska. I know what a "honey bucket" is and how it works!

Ice isn't the only thing that falls from aircraft. I remember a certain aircraft pattern bombing Florida with four cases of Budweiser cans a while back.

a reply to: JIMC5499

There was also a Christmas tree over California.

a reply to: Zaphod58

Some of the TFOA reports I read in the 80's were hilarious. They had an inert 2000 pound bomb fall into this guy's yard. The tail of the bomb was sticking out of the ground in his front yard. He wouldn't let them recover it. He wanted it for a lawn ornament. He put a sign next to it saying "You Missed! Better Luck Next Time!"

Boeing Bombs lol
yea Good old Joe DIrta .

I was going to post if it has peanuts its not ice from the wing lol .

a reply to: JIMC5499

Yeah, the Christmas tree story had me in tears. I miss the old days of write ups like that. Back when there was a sense of humor about stuff.

Thank you for all the valuable information.

What I'm getting from this is if it isn't blue, where the hell did it come from?

originally posted by: Zaphod58
a reply to: WakeUpBeer

They normally come offearly in the descent as they get into warmer air. Most of the time this happens on long haul flights when they stay in extremely cold air for a long time. It happens at other times, but the most common ones are from longer flights.

They've occasionally hit a house or car, and I think there was one that was claimed to have killed someone IIRC. The problem is that there are so many flights that it's almost impossible to narrow down exactly which aircraft it came from.

Rather round hole with a crap load of ice to be from an aircraft.

originally posted by: face23785
When I was refueling planes in the Air Force I have seen a few planes with significant ice, and it's not like I got to them 5 minutes after they landed either.

Once there was so much water spilling off a wing I freaked out thinking it was a fuel leak. Nope, just a lot of melting ice.

The fuel is well below freezing at altitude...around -40 so once it lands there can be significant build up of frost in the areas with fuel still.

a reply to: Kester

It still might have come from a plane. They have clear ice on them too.

a reply to: Xtrozero

Ice builds up in strange shapes on drain masts.

originally posted by: Zaphod58
a reply to: Xtrozero

Ice builds up in strange shapes on drain masts.

I agree but that ball looks to be 4 feet across, hell of a big ball of ice. I remember flying into the PI at Clark AFB and after an hour or two there would be 6 inches of ice under the wing. Thought about bringing out the deicer truck in 90F.

a reply to: Xtrozero

If the mast is leaking, it can build up a big chunk of ice before it breaks off. Back in February a 22 pound block of ice came off a plane and went through a garage in the UK. About a week later a foot long chunk of ice went through a roof in Canada. In 2010, something similar happened with a 2 foot chunk of ice going through a roof.

I got to fly in P2V (SP2H) Neptunes for a year before my squadron transitioned to P-3 Orion. Kind of gross, we had piss tubes hanging in the back of the aircraft which were funnels attached to heated hoses. The fluid was immediately ejected upon use, but sometimes built up into big ice chunks on the ends of the ejector nozzles that hung out the bottom of the aircraft.

Yellow bombs were observed and noted.

originally posted by: Zaphod58
a reply to: Xtrozero

If the mast is leaking, it can build up a big chunk of ice before it breaks off. Back in February a 22 pound block of ice came off a plane and went through a garage in the UK. About a week later a foot long chunk of ice went through a roof in Canada. In 2010, something similar happened with a 2 foot chunk of ice going through a roof.

Looking at the size and crater I wonder how much that thing weighed...500 plus pounds?

a reply to: Xtrozero

Depends on how high it was when it fell. Some of the smaller ones did quite a bit of damage when they hit.

originally posted by: Kester
a reply to: F4guy

It doesn't look blue in any of the images.

www.newsletter.co.uk...

Not all operations use the chemical toilet with blue water. Some use a vacuum toilet with a holding tank where odor isn't a real problem

originally posted by: face23785
a reply to: Zaphod58

I didn't know that. I was just taking a guess based on experience with our fuel storage systems. When it got cold out, our piping that was full of fuel usually wasn't quite as cold as other metal around it that wasn't full of fuel. I always figured the fuel was helping moderate the temperature, due to the FSII additive.

Actually on a lot of aircraft that use jet fuel, they use engine oil lines running through the fuel tanks to keep the fuel viscous. At -60F jet fuel has the consistency of Vaseline and doesn't flow as well as you might want it to, so they can warm it by running hot engine oil lines through the fuel tanks. It kills 2 birds by cooling the engine oil and keeping the fuel flowing easily. Ice in flight usually builds up on the leading (front) edges of anything in the airflow, so the top and bottom surfaces of the wings don't get much buildup.