Gliders with FES


SCHEMPP-HIRTH, Germany – world-leading manufacturer of sailplanes
DG Aviation, Germany – high performance sailplanes
  • DG1001-e neo, first double seater sailplane with FES system, EASA certified.
SAirKo, Lithuania – high performance sailplanes
  • LAK17C FES, self-launching FAI 15m & 18m class sailplane, EASA certified.
  • MiniLAK FES, light self-launching FAI 13,5m class sailplane, EASA certified.
  • LAK17B FES, FAI 15m & 18m class sustainer sailplane, EASA certified.
HPH Sailplanes, Czech Republic – high performance sailplanes
  • HpH Shark eS, FAI 18m class sustainer sailplane, with strong safety cockpit and many other features, EASA certified.
Avionic, Poland – producer of famous Diana 2 FES
Albastar, Slovenia – producer of UL self-launching sailplanes
  • AS15m FES, light 15m recreational sailplane.


In principle, LZ design can not offer FES retrofit for used sailplanes. Unfortunately, EASA does not approve an “Experimental registration”, like it is arranged in USA.


Exceptions are possible only for sailplanes that are Annex I types – these are by definitiony not EASA aircrafts and are therefore handled under national rules.


Most of the sailplanes which were designed to fly with some kind of engine, can be also FES equipped!

The decision about possibility of FES retrofit is usually made on two main criteria:
    The most important is the maximum weight of the non lifting parts (everything including pilot, except the wings). There must be enough reserve for additional 45kg of weight in the fuselage. If this requirement is not met, than it is not possible to install FES – due to safety reasons.
    Nose section should be as round as possible, slightly elliptic or eggy shape is also acceptable. We usually design a special spinner or adjust the front part of fuselage to be appropriate for FES installation.

FES can be installed to used sailplanes in some special cases, where type certificate holders of specific glider type are involved. These are, for example:

  • DG Flugzeugbau offers FES retrofit of some serial numbers of LS8 as published on this link.
  • Schempp-Hirth offers FES retrofit of used Ventus 2cxa

For more information about FES retrofit please contact DG Flugzeugbau or Schempp-Hirth.

EASA REGULATION (European countries)

Airworthiness and certification can be done in different ways, depending on the “type” of sailplane:

  • EASA used sailplane,
  • EASA new sailplane,
  • Annex I type sailplane (non EASA type of sailplane).

Certified EASA sailplanes require valid Certificate of Airworthiness (CofA).

If the sailplane is modified, CofA is not valid anymore.The following options are possible to make the saiplane airworthy again:

  • Initially EASA Permit to fly (PtF) can be arranged based on EASA Approval of flight conditions. One of the conditions EASA requires to issue an Approval of flight conditions is that the application for certification project is applied to EASA by DOA or ADOA organization.

LZ design does not yet hold a DOA or ADOA certificate, so we cooperate with other companies, and sailplane manufacturers which are usually certified as ADOA.


For countries under EASA regulations, Restricted Supplemental Type Certificate (RSTC) could be issued theoretically. Unfortunately EASA do not have yet available suitable procedures so that we could be actually able to arrange RSTC for different types of sailplanes (without cooperation of Type Certificate holder).


Manufacturers of new sailplanes, which are also holders of Type Certificate (TC), can apply for a major change. After certification is approved new Type certificate (TC) is issued – FES system certified as a part of the sailplane.


Ultra light (UL), experimental or home-built sailplanes are excluded from EASA regulations as Annex I types. National Permit to fly can be issued, if accepted by local CAA. Certification is arranged according to local regulations. Please check EASA fees and charges in order to fully understand the costs involved in certification!

The main factors influencing the total cost of FES installation, are:

  • single / double seater sailplane,
  • used as a pure sailplane / used, but prepared for FES installation in advance,
  • possible specific features of each sailplane type,
  • possible special local regulations and conditions,
  • required type of certification: EASA, Annex I type etc.

The manufacturers of the new aircrafts with built-in FES system, determine the final price of FES system themselves!

FES is available as a KIT only for manufacturers, who have undergone a special training of FES installation. Installation of FES system (structural modifications of fuselage, mechanical and electrical installation) requires special tools and equipment as well as certain skills and experiences. Each type of saiplane has some specific features which requires the development od special parts and arrangements. Furthermore, to legaly fly your newly FES equipped sailplane, installation should be done by all the applicable regulations.
If you are developing a new model of powered sailplane and you are interested in FES – let us know! We will advise and help you make FES installation successful, easier and safer.