WASHINGTON -- U.S. airlines could be on the front lines in a bird flu outbreak, and federal health officials are streamlining procedures for the possible quarantine of sick passengers.

But some airline workers and health experts see shortfalls in planning and recommend additional steps they say could save lives and help a financially fragile industry fly through a potential nightmare.

The Bush administration hopes quick action can contain any U.S. outbreak and has not ruled out travel restrictions.

Federal health officials have authority to detain or isolate any airline passenger suspected of harboring the avian flu virus, which scientists fear could mutate to leap from person to person and quickly spread globally.

The H5N1 virus is entrenched in poultry flocks in much of Asia. It has infected more than 120 people, killing at least 64 people in Indonesia, Vietnam, Thailand and Cambodia in two years. Last week, the first cases of human bird flu of this strain were reported in China.

Air travel was crucial in spreading the deadly Severe Acute Respiratory Syndrome, or SARS, virus around Asia and to Canada in 2003. SARS ended up killing about 800 people globally before it was contained. SARS was harder to catch than the flu and, unlike influenza, only spread after patients began showing symptoms, but airlines and health officials are basing some bird flu preparations on the SARS experience.