Damien Burke looks at an unusual visitor to Cranfield this September
An unusual visitor to Cranfield in mid-September was Scaled Composite's one-off 'Proteus' aircraft. Designed by aviation pioneer Burt Rutan, Proteus was originally envisaged as a UAV for loitering over cities and providing communications links. However it is currently in use primarily as a high-altitude weather research aircraft with NASA. Trials as a UAV with an automatic collision avoidance system fitted didn't go as well as was hoped, so letting it loose on its own isn't really an option - yet!
Being largely built of composite materials, Proteus is very light but far stronger than its stalky appearance would suggest, and has impressive performance specs, with a theoretical ceiling of 65,000 feet and endurance of up to 18 hours. The aircraft's modular construction enables quick changes in configuration - usually in the onboard sensors (mostly carried in a pod underneath the fuselage) but also in the wing configuration. Proteus, of course, was the Greek god who could change his form at will.
The fuselage proudly wears a list of records achieved along with a varied collection of zaps, though one had been stripped by the rain encountered on its first sortie out of Cranfield. Thrust is provided by a pair of off-the-shelf Williams/Rolls-Royce FJ44s mounted A-10-style on the rear fuselage, so this aircraft is not one for noise and spectacle and slips into the sky gracefully with a serene whistling sound.
The reason for its visit to Cranfield was project EAQUATE (European AQUA Thermodynamic Experiment), an experiment to validate the readings of a new sensor onboard the AQUA satellite. Proteus flew under the satellite, the Met Office's BAE 146 (the replacement for C-130 'Snoopy') flew underneath Proteus (quite some separation involved obviously!) with the result that the two aircraft could measure real conditions and that could be compared with the readings from the satellite.
Just two flights were managed during its week at Cranfield, with a fuel pump malfunction causing the aircraft to be grounded until a replacement could be flown in and fitted during a marathon overnight session by its two-man engineering support team. The pumps were apparently meant to outlast the airframe by some margin, but the airframe has proved much more useful and durable than originally expected so its increasing use does mean the occasional lifed component finally gives up the ghost.
This break in the planned flying schedule rather frustrated the local spotter community's efforts to catch the beast airborne, but both the owners of the hangar in which it was housed IAE and the operators of the Met Office 146 FAAM were very receptive to showing visitors around - many thanks to the staff of both organisations for your hospitality!
Sadly after only a week's stay Proteus departed back to the USA and on to further research campaigns in the aircraft's busy schedule.