Question, high fighter traffic, why?

[HellTriX]

I just had a curiosity about the F15s (I think thats what they are) Flying out of Portland International Airport (PDX). I see 2-4 of them every 30 minutes to 1 hour constantly landing and taking off.
I'm not sure when this started as its been going on for a long time, I think it started shortly after the 9-11 incident.

So I was just wondering why they are constantly coming and going from here, and if possible, where do they go? Do they patrol the US boarders, or fly to Hawaii islands, or Nevada?

It just interests me because these jets are at least 3 times louder than some of the largest passenger jets that take off from here and they seem to be going at least twice as fast.

What is their typical climb speed and cruise speed?
Oh and I'm interested to know how often military jets go supersonic and where they are allowed to do this? Other than the testing area in the Nevada desert are they allowed to go supersonic any where else above our country, like certain altitudes, etc?

(Hope I'm not out of place asking these questions. I'm not much of an aviation informed person, and just had some curiosities to satisfy)

Tnx

 

[AegisFC]

The Oregon ANG has a base on at the airport.
http://en.wikipedia.org/wiki/Portland_International_Airport

 

[F-15 Eagle]

I live in Milwaukie Oregon and I see them fly quit a bit recently. More than usual but I don't care. I love it when then fly over my house the more the better. To me its the sound of freedom.

 

[HellTriX]

I just think to myself, what is 2-4 jets really gonna accomplish other than to identify a threat and wait for backup. Not like I think we are ever going to be attacked in such a way as perl harbor again. So its more likely just training missions and flight time. Was just curious where they go from here or if they just fly around and come back every few hrs.

 

[F-15 Eagle]

I just think to myself, what is 2-4 jets really gonna accomplish other than to identify a threat and wait for backup. Not like I think we are ever going to be attacked in such a way as perl harbor again. So its more likely just training missions and flight time. Was just curious where they go from here or if they just fly around and come back every few hrs.

I would not rule out the possibility of America being attacked by a military threat again. Just because we don't face any right now does not mean we wont in the future. The world can change fast in just 20 years, judging by history. 9/11 was a wake up call.