BERLIN (AP) - Travelers at Frankfurt airport, continental Europe's busiest, can now enter Germany with a three-second scan of their eyes, providing they sign up for a test project for iris recognition technology.

Passengers in the six-month program still go through regular security controls, but can bypass conventional passport checks. They can simply put their passport though a scanner, take a quick look at a camera and a few seconds later enter the country, airport officials said.

To qualify, passengers would need background checks by German border police, a machine-readable passport, be citizens of the European Union or Switzerland, register at the airport and have an iris scan on file.

The test is part of efforts in many countries, especially the United States in the wake of the Sept. 11 attacks, to extend the use of biometric technology - using fingerprint, eye or facial recognition scans - to track travelers and immigrants, while also cutting down on time spent in line.

"Iris recognition is at this time the most secure biometric," Interior Minister Otto Schily, Germany's top security official said in launching the test last week. "That's why we chose it for the Frankfurt airport pilot project."

Byometric Systems of Mitterfelden, Germany, and Tokyo-based Oki Electric Industry are providing the service through contractor Bosch Security Systems. They hope to have full-scale service in place after a six-month test.

Germany passed laws after Sept. 11 attacks that provide for biometric features to be added to passports and personal identity papers. Post-Sept. 11 U.S. legislation also requires 27 countries, mostly in Europe, to add biometrics to passports they issue after Oct. 26, 2004, or else have their citizens apply for visas.