HALO, Certification work

A highly modified large business jet, a/c type Gulfstream G550, serves as a new flying laboratory for atmospheric research and earth observation for the science community. The new research aircraft named HALO – High Altitude and LOng Range Research Aircraft-, is operated by the German Aerospace Center Flight Facility Oberpaffenhofen (DLR-FX).

enviscope GmbH, together with its partner Gomolzig Flugzeug- und Maschinenbau GmbH (GFM) and in co-operation with DLR, supports scientists by direct qualification of instrumentation for the integration on HALO.


Besides the certification of the a/c and its basic installations all scientific instruments on HALO have to be qualified according to existing airworthiness standards. The certification basis for the a/c itself are the “JAR-25 change 15” regulations, and all scientific installations have to fulfil these regulations as well!

In the next years several scientific “demonstration missions” will take place on HALO. Therefore numerous new scientific instruments need to be qualified. This results in an immense workload lasting on scientists and engineers in the research organisations as well as within the certifying Design Organisation of DLR (DLR-DO).

For the qualification of the HALO instrumentation a well prepared documentation is necessary which includes technical drawings, strength analysis, installation instructions, risk assessments, etc. Most of the required documentation is unique for the experiment and needs iterative steps between scientific user, design engineer and certifying engineer of DLR-DO.

This leads to an immense workload for the DLR staff and a “bottleneck” for the scientific users on their way to their science on HALO.

This was recognized by DLR and the scientific community, and external organisations have been invited to support the access of state-of-the-art instrumentation to the new HALO research aircraft.

Contributions of enviscope

enviscope has two possibilities to meet this invitation and to assist in bringing instrument developments to HALO:

– 1. Service by instrument design, manufacturing and documentation work

Due to the experience enviscope gained in the past with a lot of the instruments of the users by

  • adapting their instruments to several platforms (e.g. Geophysica, HIAPER, Airbus A340, Learjet, Falcon, ATR-42, Do-228 and 128, Partenavia)
  • documenting the modifications for different aviation authorities

enviscope can support the scientific users using the DLR certification scheme:

The advantage for the scientific users is obvious. The scientists can rely on the experience of enviscope, they do not need to struggle with airworthiness regulations and the corresponding documentation work, they can concentrate on their main task: Science!

Nevertheless, there is only minor relief for the design engineers and no relief for the certifying engineers of DLR-DO.

– 2. Service by instrument design, manufacturing, documentation AND certification work

The extension of our service documentation to documentation AND certification comes along from the co-operation with the Design Organisation Gomolzig Flugzeug und Maschinenbau GmbH (GFM-DO).

Since more than 10 years GFM is a reliable partner of enviscope in manufacturing and certification for the enviscope operated aircraft Learjet 35A and Partenavia P68B. GFM is an EASA certified Design Organisation and is granted for repairs and changes to large and small aeroplanes.
Since HALO is a so-called “Annex II aircraft” it falls under national regulations, therefore EASA certified GFM-DO had to apply for a “National Design Organisation Approval” at the German Aviation Authority (Luftfahrt-Bundesamt (LBA)). This was prerequisite to perform certification work for HALO.

The approval procedure started end of 2008 and was finished with an LBA audit in Mai 2009. Thus all actions are taken that the consortium GFM/enviscope can support scientist and DLR in certification work for HALO!

The realisation of the second option is highly appreciated by scientific users as well as DLR because it enables access to HALO even in times of disproportionate high requests for certification. The certification scheme shows that this second possibility to serve the scientific users reduces the workload on the DLR Design Organisation dramatically!

All documentation and certification work can be iterated only between scientist, enviscope design engineers and GFM certifying engineer as long as the interface definitions between DLR-DO and GFM-DO are exchanged properly. After completion of the qualification process the experiment can be installed into HALO by the user or DLR-FX staff without involvement of the DLR-DO. This will be accomplished by delivery of a “Statement of Conformity” to the DLR-FX, accompanied by a detailed Installation Instruction.

The Installation Instruction has to describe clearly all interfaces (mechanical, electrical, gas flow lines, aerosol tubing, etc), all possible mounting locations, and all limitations. This information is sufficient for the installer and operator DLR-FX to combine the “certified” instruments with other modifications, to check whether the campaign installations fit into the envelope of the HALO Type Certificate, to perform the required ground tests, and to release the installations for flight.

The delivery of installations to HALO with a “Statement of Conformity” by GFM/enviscope gives high flexibility to the scientific operation of HALO. It even enables to change installations or to exchange instruments within a campaign without the involvement of a certifying design engineer.

Such a high flexibility is necessary for an effective scientific operation of a research platform, -with a variety of different scientific demands, -with a lot of restrictions resulting from airworthiness requirements, -and with the need for short-term changes in order to meet experimental and scientific requests.



It is a challenge to contribute to the desired flexibility in HALO mission planning and to aid in developing HALO to a modern and highly accessible research platform.

With the successfully accomplished HALO Techno Mission the first step has been done. GFM/enviscope could demonstrate in co-ordination with DLR the advantage of the sketched certification concept and is now looking forward to the HALO missions GEOHALO, TACTS, ML-CIRRUS, OMO, etc….

Please contact us if you are interested in further details about qualification procedures.