Press Release: Forum 79 Gessow Best Paper Winner


July 17, 2023 


Julie M. Gibbs

(703) 684-6777

The Vertical Flight Society Announces Winner of 2023 Alfred Gessow Best Paper Award

Selected from 21 Finalists for Best Paper from Forum 79

Fairfax, Virginia — The Vertical Flight Society (VFS) announced today the winner of the Society’s prestigious Alfred Gessow Award for the best overall technical paper presented at the 79th Annual Forum and Technology Display. This year’s winning paper is from the Crew Stations sessions entitled, “Validation of a Motion Sickness Prediction Model via Flight Tests on DLR’s Bo-105 Helicopter,” by Philippe Petit of the German Aerospace Center (DLR).

Philippe Petit - Gessow Award Winner 2023Philippe Petit graduated from ETH Zürich, Switzerland, in 2014 with a master’s degree in mechanical engineering and a focus on control engineering. He has since worked in several research positions related to aircraft and missile flight dynamics and control. At DLR he works as a researcher in the field of guidance, navigation and control and is responsible for the data fusion algorithms of DLR’s experimental EC135 helicopter, the ACT/FHS. Recently, he led the internal Project SALVARE (Safe Landing and Takeoff in low Visibility for advanced Rescue Operations), developing new technologies for the DLR “Rescue Helicopter 2030” concept. Concurrently, he is pursuing his PhD at the Technische Universität Braunschweig on the influence of motion sickness on the design of flight controls of helicopters.

DLR had previously developed a motion sickness prediction model aimed at vertical lift applications. To validate this model, flight tests with a MBB Bo-105 helicopter — owned and operated by the DLR — were conducted, as reported in the winning Gessow paper, a total of 32 test subjects were flown in 16 sorties on 30-minute sinusoidal flight paths of various frequencies. The test design and implementation included the development of a suitable measurement flight instrumentation, auditory cueing systems for accurate following of the test trajectory and questionnaires for recording motion sickness during flight. The results were analyzed, showing that the previously developed motion sickness prediction model agrees well with the motion sickness observed during flight.

The selection process, which began in October 2022, was very rigorous. Out of 330+ abstracts received, technical committee chairs selected 283 papers for publication. During the Forum, the session and technical committee chairs then selected the best papers from each of the 21 technical papers to be considered for the Gessow Award. Then the Society’s Deputy Technical Directors for Aeromechanics, Vehicle Design, Vehicle Integrity, System Integration, Systems Engineering, and Operations and Product Support winnowed that number down to six finalists. Following that, the VFS Technical Director and a committee of technical experts reviewed and ranked the papers, and in that ranking, determined that the selected paper was the best of the best. All of the best papers are available for purchase in the Vertical Flight Library & Online Store (

The full list of all 21 Forum 79 best papers (with links):

In addition, the History Committee recognized Operation Ivory Soap and the Largest Helicopter Rescue of WWII, by Paul J. Fardink, US Army (Ret.) as the winner of the Bernard Lindenbaum Best Historical Paper.

Forum 79 was held May 16-18, 2023, in West Palm Beach, Florida. Forum 80 is scheduled for May 7-9, 2024, in Montreal, Quebec, Canada. Mr. Petit will present the winning Alfred Gessow paper at the 49th Annual European Rotorcraft Forum (ERF), taking place Sept. 5-7, 2023, in Bückeburg, Germany.

Founded in 1943 as the American Helicopter Society, the Vertical Flight Society today is the international professional organization that advocates, promotes and supports vertical flight technology. For more than 80 years, the Society has provided global leadership for the advancement of vertical flight.

VFS is @VTOLsociety on social media: Facebook, Instagram, LinkedIn, Mastodon, TikTok, Threads, Twitter, Vimeo and YouTube, and has @ElectricVTOL channels on Facebook, Mastodon and Twitter.

This press release is also available as a pdf.

The Vertical Flight Society
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