Defense officials report that National Guard forces are preparing to fire bullets into an unmanned Army surveillance blimp that crashed in Pennsylvania to speed its deflation.

The blimp has been slowly leaking helium on the ground since it crashed yesterday after it broke free of its mooring at a Maryland proving ground on Wednesday and drifted more than 120 miles north into Pennsylvania.

The 243-foot-long, helium-filled aerostat broke free from Aberdeen Proving Ground at around 12:20 p.m., and a pair of F-16 fighter jets were scrambled to track it as it drifted north, before the blimp came down more than 3 hours later, North American Aerospace Defense Command said. The blimp dragged a long tether that knocked out power to thousands.

While an investigation has just begun the officials report there was no sign of any "foul play" that may have led to the accident.

The officials also cleared up conflicting reports from yesterday and revealed that the blimp does have an automatic deflation device that is intended to "slowly deflate" the blimp and allow it to settle slowly and safely to the ground if its tether breaks from the mooring.

Why it didn’t work will be part of the investigation into the accident.

The blimp that broke off and crashed contained the "fire control system" one of two blimps that are used in the JLENS system designed to identify, locate, and target low-flying cruise missiles. The second "search" blimp remained tethered and undamaged.

The two blimps were in a three-year test phase of the JLENS system, which is now suspended since they are the only two blimps available for the program. Each blimp, including research and development costs an estimated $235 million per blimp, according to defense officials

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