USAF and RAAF 707 aircraft, what is the navagation system that is used?

Not sure what your time period is but for USAF from 1970 to 1975 on a KC-135 the only navigation aids were DR, Loran A, Celestial, pressure and radar (over land).

Is IRS similar to INS as far as inner-workings go? By that I mean, do they operate on similar principles?

Lou,
According to the CS 707-300, the plane was equiped with both doppler and INS. In what instant would you use one system in place of the other.
BTW, thanks so much for taking all my question. I'm not a real pilot like a lot of people here are so I don't have a lot of resources for obtaining this type of information.

Thanks everyone, for your input on the subject.

To summarize from the information input given, the 707 aircraft
navagation system can be up graded, to virtually any navagation system available?

As I understand the USAF and RAAF still operate the 707 aircraft at the present time?

Lou

It's great to read your answers and learn from your knowledge base, as a professional pilot.

John

TWA had 707-131 ( the 31 part was the number assigned to TWA by Boeing .) This plane was a non fan engine with water injection.
Then there was the 707-331 - a larger 707 non fan plane.
Next was the 707-131B - a true rocket ship. Small 707 with fan engines. A real trip to fly!  
And then the last of the group was the 707-331B series. This included the 707-331BA, BAH and C versions. All had the larger fan engine with various leading edge flap differences and higher take off & landing weights. The BA & BAH were similar, but the H stood for heavy - it had stronger landing gear.

A side note, the 727-200 was just a few inches longer than the 707-131B. There were always the pilots that said they flew the "big" Boeing - meaning the 707, but when the 727-200 came along they had to shut-up!    Of course the 747 ended all that BS.  

Lou

BrianG asked: It would seem that the 707-131 was not a big money maker for airlines being it held less passengers that the 300 series.Was the 707-131 used on shorter routes ? It seems in general the key to making a 707 profitable would be to keep it in the air on longer flights being it used so much fuel getting to cruising altitude. But with fuel at 15 cents/gallon back then maybe that really wasn't a consideration?
And what did water injection on the engines accomplish? Was that for addition power on take off? I just remember water injected engines created much dark smoke on take off.

The 707-100 series was a bit smaller, but the seating config was even more important to the passenger numbers. We had some 707-300's that were all first class and some that were all coach and the latter was not a nice product, but was necessary to be able to make money with charter fares. Either version was able to go coast-to-coast, but only the -300's went over the pond.

The 707-131 "water wagon" was a filthy plane on takeoff. It would carry 5,500 gallons of special water that was injected into the aft section of the engine. What it was intended to do was increase thrust by adding to the mass of the exhaust. It did do that somewhat, but what it did mostly was soot up the sky with copious black smoke and make a hell of a lot of noise. You had to use all the water since any left over would freeze in the tank and cause problems. Most pilots hated to use the water and some dumped it on the taxiway before take off. 

I remember taking off out of Shannon on a charter at max gross with a 707-331 and using every foot of the runway.   This was an underpowered plane if there ever was one. The 707-131B on the other hand was a hoot to fly - Hang On here we goooooooo...  

Lou