Flawed Body Armor Tests: “Rounding” Measurements

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The October, 2009 Government Accountability Office (“GAO”) report to Congress, entitled “Independent Expert Assessment of Army Body Armor Test Results and Procedures Needed Before Fielding,”  confirms deviations from approved US Army testing protocols, “the majority of which seem to make the testing easier to pass and favor the vendors . . .”   One glaring example of this skewed testing in favor of military suppliers are “Rounding” Measurements of Back-face Deformation (“BFD”).

When a test bullet strikes the target ceramic ballistic protective plate and does not penetrate the plate, the impact of the strike can make a depression in the clay backing placed behind the plate to simulate the plate being worn on a torso.  In the ballistic testing world, this depth of this depression is called BFD, and the degree of BFD is can be cause for assigning a “limited failure” or even a “catastrophic failure” to that specific test plate, depending on the measured BFD.  (Visualize the depth of the BFD to the clay backing of a test plate and then visualize having your sternum or spinal column depressed by 1.7 inches to 1.9 inches to get an idea of why BFD  is a “BFD”.)

For the testing reported on by this GAO inquiry, for a first test shot a BFD greater than 43 millimeters (1.7 inches) but less than 48 millimeters (1.9 inches) is evaluated as a “limited failure,” while a BFD “greater than 43 millimeters on a second shot” also qualifies a “limited failure.” Any BFD on any shot equal to or greater than 48 millimeters is evaluated as a “catastrophic failure.”

During these Back-Face Deformation Tests (“BFD”), the GAO noted:  “Army testers rounded down back-face deformation measurements which is not authorized in established testing protocols . . .”    Take a deep breath, and read that sentence again.   The Army and the DOT&E had a choice when it came to rounding (if they wanted to do it at all). They chose to round down.   Here’s an example cited in the GAO report:  On one shot with a BFD measured as 43.306, the Army recorded the 43.306 mm BDF as a 43 mm BFD, and the shot went from “failed” based on empirical data, to passed (with no penalty).  

GAO wrote about the overall test sample (of 14 shots) from which the immediately preceding BFD data was taken:   According to official test data, only 7 of these 14 shots were failures (50 percent). This is due to the Army’s practice of incorrectly rounding down back-face deformations during First Article Testing [phase 2].  One shot that resulted in a back-face deformation of 43.306 was officially rounded down to 43 and not penalized, but had Army testers [and their DOT&E overseers] followed the protocols and not rounded this result down, 8 of the 14 shots would have resulted in penalties.

The result is crystal clear: When presented with an opportunity to select an option that could have decreased risk to Soldiers while increasing risk/cost to contractors, the Army and DOT&E chose the opposite. DOD chose the option that increased risk to Soldiers while reducing risk/cost to contractors.

 Pouring salt into the Army/DOT&E festering sore, GAO wrote:  “. . . officials we spoke with from one private industry ballistics testing facility said that their practice was to always round results up, not down . . . As a result of rounding [down], two designs passed First Article Testing that would have failed if the measurements had not been rounded.”

If you are keeping score:  Contractors – 1   Soldiers – 0

Unfortunately, there is more to these consistently contrived test procedures that I will report in subsequent news articles for SFTT.

Roger Charles

SFTT Editor

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