Reaction Engines Scimitar

The Reaction Engines Scimitar is a derivative of the SABRE engine technology, but intended for jet airliners (the Reaction Engines LAPCAT A2 concept), rather than space launch applications. Consequently, most of the Scimitar engine technology is similar to SABRE but designed for much longer life.

Source: Wikipedia — Reaction Engines Scimitar (CC BY-SA 4.0)