An aircraft refuelling probe is generally required to be moveable between a compact, stowed, state in which it does not contribute significantly to the drag of the aircraft, and an extended, deployed, condition in which it projects away from the aircraft, within the pilot's field of view so that he can manoeuvre it into a drogue towed by a tanker aircraft. The space on board the aircraft available for storage of the stowed probe is usually very limited. In addition, the probe must be capable of withstanding significant loads during the coupling and uncoupling process and these loads must be dissipated appropriately through the airframe structure. At the same time, however, it is important that the natural flexing and movement of the airframe structure in response to flight loads does not impose an undue load on the probe, either when stowed or extended.

Accordingly, in one aspect, this invention provides an aircraft deployable probe assembly which comprises: an elongate telescopically extendable probe element; an inner mounting means adapted for attachment in use to an aircraft structure to support an inboard proximal end region of said probe element, said inner mounting means

comprising a spherical joint arrangement allowing angular movement of said probe element about at least two generally orthogonal rotational axes; and an outer mounting means spaced along said probe element from said inner mounting means and adapted for attachment in use to said aircraft structure to support a spaced region of said proximal end region of said probe element, said outer mounting means being adapted to allow one or more of linear movement of said probe element in a longitudinal direction and angular movement of the probe element with respect to said outer mounting means, wherein said inner mounting means comprises an internal collar element supporting the inboard proximal end region of said probe element and is carried within an external collar element secured to said aircraft structure.

By this arrangement, the inner and outer mounting means provide an extent of compliancy which accommodates at least some of the relative linear and/or angular movement of the aircraft structure supporting said inner and outer mounting means.

Said spherical joint arrangement may comprise a gimbal arrangement or the like.

The arrangement of said outer mounting allows angular movement about the three rotational axes, as well as sliding movement in the longitudinal direction of said probe element.

To allow rigging and set up of the probe assembly, said

inner mounting means preferably comprises rotational adjustment means for allowing angular adjustment of said probe element.

Whilst the above arrangement may be used for a variety of different probes that may be deployed from an aircraft, the arrangement has been designed with an aircraft refuelling probe in mind.

The invention also extends to an aircraft incorporating a refuelling probe as set out above.

Whilst the invention has been described above, it extends to any inventive feature or combination of features set out in the following description or claims.

The invention may be performed in various ways and an embodiment thereof will now be described by way of example only, reference being made to the accompanying drawings, in which:- Figure 1 is a schematic side view of a portion of the front fuselage of an aircraft incorporating a probe assembly in accordance with this invention, with the probe shown in both the extended and the retracted positions, and Figure 2 is a front view on the port side of the aircraft of Figure 1.

The probe assembly 10 is mounted between two adjacent frames 12 of the airframe structure. The longitudinal axis 14 of the probe assembly is disposed outboard of the aircraft central line 16 and inclined at an angle thereto.

The probe assembly 10 comprises a proximal tube 18, two intermediate tubes 20 and a distal tube 22 carrying at its

free end a refuelling nozzle 24. When stowed, the nozzle is disposed in a trough 26 which extends to the aircraft fuselage skin and is covered by a deployable door 27. The trough 26 may be used as a structural load carrying member, for example if load removal from the surrounding structure makes this desirable. The trough 26 provides an envelope for the nozzle to park when retracted and provides protection from the elements for both the nozzle and the bay beneath the trough.

The proximal tube 18 is located within a fuel cell 29 disposed in the side of the aircraft to the rear of an air inlet 31. The outer end of the proximal tube passes through a fuel seal 33. The proximal tube 18 of the probe assembly is secured to the adjacent structure 12 by means of an inner mounting assembly 28 and an outer mounting assembly 30 respectively. The inner mounting assembly 28 comprises an internal collar 32 which fits over the surface of the proximal tube 18. The outer surface of the internal collar 32 is spherical and received in a complementarily formed external collar 34 which is attached to the structure 12.

The inner mounting assembly 28 allows rotation about two axes orthogonal to the longitudinal axis 14 of the probe.

A torsion arm 38 provides rotational adjustment which facilitates rigging of the assembly to align the probe nozzle 24, and to allow for build tolerance.

The outer mounting assembly 30 comprises an internal collar 38 which is a sliding fit over the external surface of the proximal tube 18. One or both of the engaging faces

may be provided with a low friction coating. The outer surface of the collar 38 is spherical and received in a complimentarily formed bearing member 40 which is attached to the forward frame 12. The outer mounting assembly 30 thus allows restrained fore and aft movement and relative pivotal movement.

Thus, the inner mounting assembly provides restraint in all three linear directions, whilst allowing rotation about axes other than the roll axis, and the outer mounting assembly provides restraint in the up/down and lateral linear directions, whilst allowing linear movement in the longitudinal direction and angular movement about all three axes.

The arrangement therefore provides secure restraint for the probe in both the stowed and deployed conditions but is compliant to allow movement to accommodate linear or angular relative movement of the structure.

The probe can be removed and re-installed easily for maintenance and/or for missions which do not require an inflight refuelling capability. In addition, if adequate provision has been provided in the airframe, the probe can be retro-fitted.

In view of their location, the linear and spherical bearing arrangements are selected to perform satisfactorily in fuel.

The whole assembly is mass critical and the design is intended to provide good or optimal mass vs. load capability. In addition, the assembly allows the

arrangement to be a line replaceable unit due to the ease of installation/removal.

The probe is extended and retracted by means of a rotary actuator and an internal operating mechanism (not shown).

The position of the rotary and axial load reaction can optionally be modified to suit load requirements; for example the loads may be reacted at the top or the bottom of the installation.

Furthermore, the arrangement presents the free end of the extended probe at a good position for coupling with a drogue, well away from other aircraft parts susceptible to damage by the drogue, and in good line of sight for the pilot of the aircraft.