The "DC-10 as water bomber" thread reminded me of an article
I read recently, and I was able to dig it up.


The following article appeared in the August 2003 issue of
Boeing Frontiers, the internal Boeing company magazine:


Water bombs
Boeing invention could make C-17 a firefighter
BY RICK SANFORD

A beach ball-sized water bomb may some day take the danger out of aerial
firefighting and greatly reduce the time and cost to extinguish a blaze.

The concept stems from a program sponsored by the Boeing Chairman's
Innovation Initiative, which provides the context for Boeing people with
great ideas to create new businesses.

An idea from William Cleary, a project manager in the Boeing Integrated
Defense Systems Advanced Airlift and Tanker organization, involves an
out-of-the-box method of fighting fires.

Dropping water or fire retardant on a fire requires conventional aircraft
to swoop dangerously low in order to deliver their cloud of liquid where
needed. Heat and thermal winds make the chore challenging, dangerous and
often less effective.

"The sooner you can knock a fire down, the better," said Cleary, a designer
of the proposed water bomb system. "In May of 2000, New Mexico's Los Alamos
fire burned for three days before exploding into a 500-square-mile behemoth."

So how does a beach ball do the trick? The system, called Precision Aerial
Fire Fighting, uses up to 2,800 biodegradable, faceted spheres stacked on
pallets within cardboard containers. This delivery technique is similar to
the way U.S. Air Force C-17s airdropped yellow humanitarian ration packages
to Afghanis in 2001.

The unit's spherical shape minimizes airflow resistance. Each sphere contains
50 pounds of water and easily remains intact while it falls true to target.
The spheres burst on impact at the heart of the fire. A single C-17 PAFF
mission could airdrop 140,000 pounds of water on multiple "hot spot"
targets-equivalent to nearly 100 helicopter deliveries.

"What's more," said Cleary, "the C-17 can airdrop from 1,000 to 2,000 feet
above ground level using precision navigation and airdrop instrumentation,
remaining safely away from the fire and winds," he said. "If a C-17 were used,
this delivery system is remarkably cost effective, and the savings in lives
and property make it an interesting possibility for the Air National Guard."

As with today's aerial firefighting, a ground safety fire commander would
ensure ground personnel are clear of the airdrop zone and would direct
airdrop targeting.

Advantages of C-17 Precision Aerial Fire Fighting
1) Safe aircraft altitude for airdrops
2) Use of collapsible, biodegradable containers
3) No special aircraft-equipment-corrosion problems
4) Multiple "hot spot" targeting with one aircraft
5) Increased payload, coverage, and speed to fire
6) All-weather/terrain aerial firefighting day or night
7) Computer-aided targeting
8) Bomblets falling true to target with an even burst

Significant resources are spent each year at local, state and federal levels
to fight wildfires. California alone spends $1.3 billion annually fighting
wild land fires.

The next phase of Precision Aerial Fire Fighting would include aircraft
airdrop testing later this year. Based on analysis to date, this testing
would verify that the PAFF system offers immediate containment of potentially
devastating forest fires and pave the way for development of this innovative
weapon in the war on fires.