S.C.U.B.A.  Diver in the Tree

Jon Up North

This debunking is dedicated to the memory of Steve Horton, pilot, and dearest friend. Killed in the Maldivian Air Taxi accident, December 3rd, 1999

This will be quite the trick to type given a broken keyboard and dislocated shoulder. *Note* I have no "a" key and am having to cut and paste to get a.. so if you see a 'v' where an 'a' should be, just let it slide :)

As most of you know, I work for the Forest Service doing what can best be described as Flight Services and dispatch for the aircraft which fight the forest fires here (actually, wildfires in general). This means I get to play with lots of cool toys, and get to be around the helicopters and fixed-wings quite a bit.

I've seen two versions of this Urban Legend. 1 where the diver gets scooped up by a helicopter, 1 where the diver is scooped by a fixed-wing water bomber. I'll address both.

Regarding the helicopter:

Helibuckets (most commonly "Bambi buckets") come in a variety of sizes depending on the lift capacity of the helicopter to be using it. The largest size is for helicopters such as the Sikorsky S-61. The opening of the bucket has a 1 foot ring, with 10 arms radiating out of it to the flexible bucket material. The rim of the bucket then has 8 straps which are attached to the sling which the helicopter uses to carry the bucket. The construction is such that there is no way you could fit a human, let alone a diver with scuba tank, bcd, and other equipment, into the bucket. So that is problem #1.. You may be able to fit 10,000 gallons of water in it, but a person wouldn't get through the top opening.

Problem two with the bucket is the bottom opening. The bucket doesn't open up its entire bottom to drop its load. There is a solonoid valve which opens about a 6" X 6" opening in the bottom. -I'm going to digress here and tell you why this is so-. When fighting a fire from the air, you don't want to drop the water as one big 'package' because it will fall through the burning trees and end up mostly on the forest floor. What you want is a 'cloud' of water to envelop an area (such as a tree). To get this 'cloud' the water is droped through a smallish opening from several feet above the area targeted, and at a forward velocity of 10 or 20 KT/hr. This causes a spray of water to hit the area, and it is more spread out so it doesn't just leak to the forest floor. I'll try to post pics of the bucket, and the bucketing operation later today.... done digression.

So even if you managed to get someone in your bucket, they wouldn't be dropped out... they'd be along for several rides.

"Okay," you say. "You can't get a diver in the bucket, but you certainly could get him tangled up in the bucket and have him become untangled over the fire." There are problems with this too. Given the cost of aerial fire supression, one wants to get the maximum benefit from it. We use buckets on helicopters which essentially max-out their lift capacity when full of water. The addition of a 160 lb diver with about 70 lbs of equipment (230 lbs in total) would make lifting very very difficult for the chopper to do in addition to its water load. This would result in performance changes noticable to all but the most inept pilot. Further, when 'dipping' a bucket to pick up a water load, the pilot is watching the bucket VERY closely (through the descent, dip, and ascent). The reason is that a pilot really doesn't want to snag something and crash his helicopter. Death is a powerful motivator. The pilot would see the diver, and probably simply eject his sling-line...

There are further complications to the matter as well. Unless the fire is extremely close to a lake large enough to dip in to, most of the time pilots simply dip into beaver dams. They are deep.. they are ubiquitous.. Most divers display the red flag with the diagonal white stripe when diving so that boaters, etc. know they are beneath the surface. This would be noticed.

I think it is fair to say that scooping up a scubadiver is about as near to impossible as one can get.

On to the water bombers:

This is quite easy to debunk (hence why it is generally the lesser circulated version). The water bombers which actually 'scoop' from lakes are built here in Canada by Bombardier (that's pronounced Bom Bard eeeyay, not bom-ba-deer). The are the CL-215 and CL-415 series. The intakes for the water on these bad-boys are very, very small. There are two of them, and they are each about 4 inches by 10 inches. You couldn't get a diver into one. Further, they have a grille over them consisting of spaces about 1.5 inches by 1.5 inches. The only way you'd get a diver in one is if you first put him in a large blender. -I'll put up some pics of these intakes soon, too.

The very last type of aerial water delivery aircraft are "helitankers" these are choppers with a fixed tank built into them which suck water through a hose we call a "Donkey dick" (it looks like one). The hose opening is a couple of inches in diameter and sucks up water though a pump, so you'd have to have a very very small diver who could make it through the hose *and* the pump. Certainly if such a diver were found (he'd have to be smaller than an inch) there would have been much talk of it in the scientific community: "Smurfs live" would be the headline.


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