Retrofitting the H145 with a five-bladed rotor system (BK117 D3)

DRF Luftrettung is again making use of pioneering innovation. Having been the world’s first operator of the H145 helicopter type, it developed the processes for retrofitting the helicopter with a new five-bladed rotor system in conjunction with Airbus Helicopters in spring 2021. These processes now serve as the model for all further retrofit


A task for professionals


The technicians at the DRF Luftrettung Operation Center will be independently retrofitting all existing H145 aircraft used for missions at DRF Luftrettung with the new rotor system over the next few years.

Thanks to the service bulletin retrofit available since May 2021, the EASA Part-145 maintenance and repair organisation at DRF Luftrettung can provide all H145 (BK117 D2) operators worldwide with an upgrade of their helicopters to the new version (BK117 D3) and let them benefit from the deep experience of the MRO.

Benefits of the new rotor system:
  • Retrofitting existing aircraft with the five-bladed rotor improves their performance. With the new system, the H145 becomes lighter and the maximum take-off weight rises to 3,800 kg. This means that crews can carry larger loads on board. If necessary, more fuel can be carried to fly longer distances.
  • The helicopter cuts through the air even better thanks to its five rotor blades, which further increases the comfort for the crew as well as the patients.
  • The hingeless rotor head improves maintenance as it removes the need for oil, grease and storage.

Elements of the retrofit:

  • In addition to the rotor blades and mast, the service bulletin retrofit involves further helicopter parts that are swapped out during the retrofit process. They include modifications to the transmission, exchanging the batteries and updating the software. A total of 16 service bulletins need to be worked through.
  • The damper for the landing gear is removed as it is no longer needed. Changes are made to the electrical wiring and an additional hydraulic pump is installed (for ground tests).
Jan Berger
Jan Berger

Technical Sales Manager

DRF Stiftung Luftrettung gemeinnützige AG  


Laval Avenue E312  

77836 Rheinmünster  


Telefon: +49 (0) 711 7007 3000 

Email: sales-service@drf-luftrettung.de