Can't use parts already owned in career mode

[safejrz]

I bought some parts at the R&D center but they do not appear available at the Spaceplane hangar :

http://s15.postimg.org/baixp1b0b/tech.png

So I expected to see the Whiplash engine somewhere:

http://s24.postimg.org/gzw3gtl5x/000.png

Am I assuming something wrong? Do I miss a pre-requirement somewhere to use those parts?

Thanks!

[sal_vager]

Hi safejrz, I see you're using a 1.0.4 save in 1.0.5, several of the aero parts were moved to new tech tree nodes but they remain in the old nodes in the persistent.sfs to avoid breaking the save.

 

The turboramjet is now in Hypersonic flight.

 

Also, parts you already researched that were moved may have to be researched again to re-unlock them.