Nearly three years after the Sept. 11 (search) attacks, two key elements of the Bush administration's (search) effort to bolster airport security remain works in progress: more rigorous background checks of passengers and a better way to check for explosives in luggage.
A plan to prescreen air travelers for terrorist connections, once described by the administration as an urgent need, has been sent back to the drawing board. And only eight of 441 commercial airports have systems recognized as the best at quickly and effectively screening checked baggage.

The reasons for the delays are varied. Technology problems and privacy concerns doomed the passenger prescreening program, while the enormous cost — an estimated $5 billion — has held up progress installing large bomb-screening machines in airports.

Security slip-ups: Are we safe and secure or still unsure?

A sample of your responses:

I think we are still vulnerable to terrorist on planes. We are tied by our very own laws of no racial profiling, rights of privacy and freedom of religion to name a few. All of this is hard to coexist to counter the enemy.
Jason H.
Memphis, TN

To be honest, I am scared for my family at home more than I am of my own safety... and I am in Iraq.
Nicholas C.
Baghdad, Iraq

I have to believe that air travel security is safe and secure enough to not consider the alternative.
Rob S.
Shelby Twp., MI

As long as terrorists are determined to strike, we have to remain vigilant. I have faith in Homeland Security as an airline worker; that they are doing everything possible to keep us safe.
John L.
Las Vegas

At this point I think terrorists know that Americans aren't just going to sit there and be idle in any type of hijacking situation.  We no longer think of hijackings like political statements that may end peacefully. Air Marshals, extra security, extra screening for explosives and such do help and are needed, but our main security on a flight during a potential hijacking is the example the American people saw on 9/11. Terrorists know that at this point a plane full of Americans will not just sit there and be taken over like the flights before.
Taylor G.
Phoenix, AZ

I think we are safer with air marshals on board, however it's kind of hard to filter the enemy out with our freedoms, i.e., right of privacy. I'll say this though: If I'm ever on a plane and some crazy jerk pulls out a box cutter or some other weapon I'd do my best to kill him with my bare hands before he can even get to the cockpit. I'd give my life for 2 people or 80 people. I'm not the only one who shares this conviction. I would think if I died doing that then it was my destiny and purpose in life.
Jason
Cordova, TN

This country can never be protected against every method of attack by terrorists. Our borders are to open and our neighbors are unwilling to cooperate or understand the need for Security in this war or terrorism.
Wanda M.
Jessup, MD

I think we are safer, I'm sure many incidents have been prevented that we are not even aware of, and plenty of plots have been abandoned because of our security measures.
Catherine M.
New Port Richey, FL

A few weeks ago we learned the Govt. sued several airlines for removing suspicious Arabs from their planes after 9/11. With the booty won, the Airlines must now provide "sensitivity" training for all their employees. There's much hypocrisy connected to this "war" that makes me wonder when the real war begins.
Carol P.
Sebastian, FL

Send your comments to: friends@foxnews.com

- Note: The views and opinions expressed on this page do not necessarily reflect those of FOX News or its subsidiaries