aircraft type eval not working on older aircraft

So how come when you go into the aircraft type evaluation, the older aircraft such as MD-80’s, 90’s, and the B757 doesnt work? It just says “This type cannot operate on the selected relation or is not available with the specified range”. This doesnt make any since cause we are talking about for example these routes which definitely are within the range limits.

SFO-LAX

SFO-LAX

SFO-ORD

SFO-MEX

Why isnt this working???

It says "…not available with the specified age"… not "range"…

Modify the selected aircraft age and it will work.

But some aircraft types cannot be compared as they can never have the same age (B787 and B707, for example…)

Thanks a lot for that answer XD I never saw you could change the age on the research !!

I feel so noob suddenly XD