Aerodynamic Stability Measurement of Seaplane Twin Floats: The Role Type of Control Surface Variations

Sulistiya; Fauziah Kasmin; Rachman Sinatriya Marjianto; Teguh Herlambang; Zuraini Othman; Widyawasta; Mohd. Sanusi Azmi; Yudiawan Fajar Kusuma; Meedy Kooshartoyo; Ilham Akbar Adi Satriya

doi:10.48084/etasr.15271

Authors

Sulistiya Research Center for Transportation Technology, National Research and Innovation Agency, KST BJ Habibie, Setu, South Tangerang, Banten, Indonesia
Fauziah Kasmin Department of Intelligent Computing and Analytics, Faculty of Artificial Intelligence and Cyber Security, Technical University of Malaysia Melaka, Melaka, Malaysia
Rachman Sinatriya Marjianto Department of Engineering, Faculty of Vocational, University of Airlangga, Surabaya, Indonesia
Teguh Herlambang Faculty of Business Economics and Digital Technology, University of Nahdlatul Ulama, Surabaya, Indonesia
Zuraini Othman Department of Diploma Studies, Faculty of Information and Communication Technology, Technical University of Malaysia Melaka, Melaka, Malaysia
Widyawasta Research Center for Aeronautics Technology, National Research and Innovation Agency, KS Jacob Salatun, Rumpin, Bogor, West Java, Indonesia
Mohd. Sanusi Azmi Department of Software Engineering, Faculty of Information and Communication Technology, Technical University of Malaysia Melaka, Melaka, Malaysia
Yudiawan Fajar Kusuma Research Center for Hydrodynamics Technology, National Research and Innovation Agency, KST B.J Habibie, Setu, South Tangerang, Banten, Indonesia
Meedy Kooshartoyo Directorate of Laboratory Management, Research Facilities, and Science and Technology Areas, National Research and Innovation Agency, KST BJ Habibie, Setu, South Tangerang, Banten, Indonesia
Ilham Akbar Adi Satriya Research Center for Aeronautics Technology, National Research and Innovation Agency, KS Jacob Salatun, Rumpin, Bogor, West Java, Indonesia

Volume: 16 | Issue: 3 | Pages: 35716-35722 | June 2026 | https://doi.org/10.48084/etasr.15271

Received: 2 October 2025 | Revised: 29 November 2025 and 24 January 2026 | Accepted: 11 February 2026 | Online: 6 June 2026

Corresponding author: Rachman Sinatriya Marjianto

Abstract

The aerodynamic design of twin-float amphibious aircraft is challenging because airflow interactions between the fuselage, wings, and pontoons can interfere with one another. Most prior work has examined water performance but offers less analysis of aerodynamic control authority. This study fills a gap in the literature by measuring aerodynamic stability derivatives and control surface effectiveness for a twin-float configuration in subsonic flow. Wind tunnel tests were conducted at flow speeds of 35–65 m/s and angles of attack from −10° to +18°. A six-component balance was used to record forces and moments for different aileron, rudder, and elevator deflections. The analysis indicates that the effectiveness of the control surfaces is linked to the wake produced by the float in a non-linear way. Aileron deflection increased the rolling moment coefficient (C_roll) slope by about 60%, which preserved lateral control authority even at high angles of attack. In contrast, increasing rudder deflection raised the yawing moment coefficient (C_yaw) by about 90%, but it also increased yaw–roll coupling, so crosswind maneuvers required corrective inputs. Elevator deflection demonstrated strong control over longitudinal stability. Positive deflections increased the nose-down pitching moment by about 70%, which helped offset the pitch-up tendency associated with the float. These results provide aerodynamic data that can be used to refine flight control laws and to define stability envelopes for designing next-generation amphibious aircraft.

Keywords:

estimation, seaplane, amphibious aircraft, control surface, aerodynamic performance, wind tunnel test

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