Oversight To Blame For Last Year's Blimp Escape

ABERDEEN, Md. (WJZ) -- We now have a better understanding why an unmanned blimp from the Aberdeen Proving Ground broke loose and floated across Pennsylvania.

As Mike Schuh reports, a simple oversight led to an expensive, dangerous day last October.

How did the unmanned blimp get loose from its base in Baltimore County? We now know why: its pitot tube. Every aircraft you've flown aboard, from Cessnas to jetliners, has had one. On planes, it determines airspeed. On the blimp, it tells operators how windy it is and monitors how much air is inside the blimp.

Somehow its pitot tube failed and no one noticed, so fans that should have kept the balloon inflated didn't turn on. The blimp went soft and could no longer keep its nose into the wind; it turned sideways and began shaking. The strain on the tether was too much, so it snapped and off went the aerostat, headed towards Pennsylvania.

The three-and-a-half ton balloon is supposed to sense that it's broken free and automatically deflate itself. That deflation system is battery powered and, for reasons not revealed, those batteries were never installed.

The blimp finally bounced and scraped enough holes in itself to become snagged in some trees in the middle of Pennsylvania.

State troopers used shotguns to pop what was left.

Even before this event, the Pentagon said the radar system had poor reliability and serious deficiencies.

The aerostats are still grounded. Congress is looking to see if the troubled program is worth saving and the Pentagon will soon ask for $27 million to restart the experiment this fall.