Robin X4
| X4 | |
|---|---|
| Role | Experimentalfour-seat light aircraft |
| National origin | France |
| Manufacturer | Avions Robin |
| First flight | 25 February 1991 |
| Number built | 1 |
TheRobin X4was anexperimentalFrenchfour-seat light aircraft designed and built byAvions Robinto test different wing configurations and construction materials.[1]The X4 was a low-wingmonoplanewith atricycle landing gearand powered by a 116 hp (87 kW) Textron Lycoming engine.[1]
Design and development
[edit]Originally designed as a 4-seatATLaircraft, and at the time called the ATL II or ATL.FAR23,it was later intended to become a long-term replacement for theDR.400series of aircraft.[2]After Pierre Robin soldhis company,the name was changed to X4, X for experimental and 4 for 4-seater; the design was also changed from theATL'sV tailto a more conventionalcruciformtype. The fuselage was fibreglass and epoxy in aNomexsandwich, which allowed more fluid curves, and was generally triangular in cross-section, like theMe 262.[3]The landing gear was from a DR.400, and the forward-tilting canopy from anATL.[4][5]The wings were wood and fabric, like those of a standardDR.400,but of constant dihedral; the wooden construction allowed modifications to be made quickly and cheaply.[4]The rudder and ailerons were of metal construction.[4]
It first flew on 25 February 1991, with Robin head of development Daniel Müller at the controls; whilst designed as a four-seater, only the front two seats were installed with the rear being taken up with test equipment. The airframe was used to test various wing profiles, especiallylaminar flow;the feasibility of producing a composite-material aircraft; and to test new systems (e.g. rod rather than cable controls).[4]
Testing atSaint-Cyrshowed a slight advantage to the X4 when compared to the equivalentDR.400/120, despite, according to Müller, its 'tired'[6]engine. For example, optimisation of the cowling reduced engine cooling drag by 20%, or 5% of global drag; in total there was a 25 km/h gain in cruise speed.[7]However, the improved performance came at the cost of a non-benignstallunsuitable for a training aircraft.[6]According to Robin and Besse, the airframe was capable of eventually being a whole series up to 4+2 seat configuration with correspondingly larger engines, and be a potential competitor to theCirrus SR22.The new owners ofAvions Robinwere not interested in the design, and it was ultimately scrapped.[6]
Variants
[edit]- Robin X4
- Lycoming 116hp O-235N engine, registration F-WKQX; one built; voluntarily destroyed
References
[edit]- Notes
- Bibliography
- Besse, FrancoisLa Saga Robin (de 1957 à nos jours).Mayenne: Jouve, 2012.
- Lambert, MarkJane's All the World's Aircraft 1994-95.Coulsdon: Jane's Information Group, 1994.ISBN0-7106-1160-9
- Masse, XavierAvions Robin (du Jodel-Robin de 1957 au DR.500 de 2000).Paris: Nouvelles Editions Latines, 2000.