The public radio station said the trial of the body imaging security scanners has been plagued by serious problems. The units, which have been in use since September, are apparently unable to tell the difference between foreign objects and such things like pleated clothing.
The scanners use millimetre-wave technology to produce outline images of bodies, with each scan lasting less than three seconds.
While some passengers are being asked to remove thicker clothes such as jumpers, NDR reported that the devices are regularly malfunctioning due to creases in lighter clothes such as blouses and skirts.
Although use of the scanners remains optional, every passenger must now also be patted down and pass through a metal detector, whether or not they have been scanned.
The extra security checks are causing delays, resulting in longer lines and irritated passengers.
New software due to be installed to solve at least part of the problem is not yet ready for use, NDR reported.
The scanners has previously been criticised by civil liberties campaigners the world over, mostly due to fears of how the images would be stored.
Plans to fast-track tests of the controversial body scanners were announced in January following the foiled “underwear bomb” attack in Detroit on Christmas Day 2009. The trial period is due to run until the end of March 2011.