Originally Posted by
EAP86
Probably Line Replaceable Unit. I think the Tornado originally came with the LRMTS (Laser Ranger Marked Target Seeker, in a fairing under the front fuse) and the GR4 upgrade brought in NVGs and FLIR (in another fairing next to the LRMTS).
EAP
Certainly LRU is Line Replacement Unit. The LRMTS was incorporated as Mod 00080? on the very earliest UK Tornados, I remember seeing a Civilian Working Party doing the task in the early 80s. It became part of the build standard around batch 2 or 3 I guess and continued from there. German and Italian aircraft didn't have it.