HIFR
The Royal Navy Merlin have trialed many a HIFR but have now realised due to the sheer size and weight of the bloody thing, it burns as much fuel through the three engines as what it can take in during the actual HIFR!! (from a merlin engineering friend!)
HIFR in the RN still remains essential when on missions such as Anti Surface Warfare where they are a long way from mother ship. The SAR role may use it also whenever there is a frigate around on their way to a long ranger.