RotonBy Jonathan PearsonAcknowledgementsLaurent Esmiol for correcting my French. Contents
The Roton is a class of vertical take off and landing (VTOL) interface vehicle. Unlike other interface vehicles it is based upon a helicopter concept rather than an aeroplane or missile form. The Roton was first developed as a usable interface vehicle by Flame Spiral Industries of New Zealand. The relatively small market for such vehicles has meant that FSI remain the dominant supplier of Rotons to the civilian market. FSI have however licensed their technologies and designs to a wide range of companies of various nationalities. The VTOL ability of the Roton makes it ideal for military landing operations as it is capable of landing on unprepared ground. In addition the Roton can operate equally well within a vacuum (unlike aeroplane based interface vehicles) making it a very flexible asset. The aerospace division of Canadian industrial conglomerate Gunner-Long produce the most popular versions of the Roton for military use - the GLR-GA, GLR-MU and the GLR-MT. The GLR-GA, exported as the Ouragan (Fr: Hurricane), is an armed version of the roton equipped with a combined point defence / ground attack dual plasma gun system capable of delivering combat troops or equipment from orbit into a medium to low threat landing zone. The GLR-MU, exported as the Cyclone, is an unarmed version of the GLR-GA while the GLR-MT, exported as the Tourbillon (Fr: Whirlwind), is a dual contra-rotating rotor transport capable of moving 500 tonnes from orbit to a low threat landing zone. NarrativeEnseigne Jeannette Montcalme switched her virtual cockpit over to tactical to watch the progress of "Les Paras" towards the tertiary landing zone. The Roton's EW system queried the troops IFF transponder and updated the position on her plot - about 10 minutes to rendezvous. The previous evening her Ouragan had delivered the same men and women to a small forest clearing from the troopship orbiting Joi. The autopilot had dropped the Roton into the clearing with so little disturbance that that the roosting flying foxes barely bothered to open their eyes to watch the alien vessel descend. Jeannette had toggled the exit ramp while her gunner monitored the passive sensors for any sign of Elysian rebels ("les grenouille" as the Paras called them). When Rabea reported that there was no rebel activity visible on any of the spectra available to her Jeannette had informed Capitaine Mejdoub that his mission was a go. Giving her head a quick shake to dismiss her recollections Jeannette scanned the display once more for signs of the Paras' pursuers. Although the landing had gone undetected the Paras' approach to the rebel base had been spotted by a grenouille LTA drone operating beneath the forest canopy. Unfortunately the Paras had not spotted the drone and had walked straight into an ambush. They had managed to break contact but had been cut off from their primary and secondary pickups by a second group of grenouille returning from a patrol. With no enemy icons on her display Jeannette told the autopilot to begin final approach. She often wondered what purpose she served sitting in the Ouragan's control cabin as the Roton had all the manoeuvrability of a flying brick and only two directions of travel - straight up and straight down! Nevertheless MSF regulations required that all passenger carrying interface vehicles should have a human pilot so here she was. "I've got the
Paras on visual" reported Rabea as the tac display updated itself.
"Tango Delta to
Alpha Uniform we have been acquired, what is your situation? Over." The encrypted comm meant that Jeannette was unable to tell if it was Mejdoub on the other end of the link, she hadn't had a status update on the Paras casualties as they'd lost their long range comm in the ambush. Jeannette's tactical display had been updated by the phased array radar activated by Rabea and showed two other grenouille drones (both recon versions fortunately) in detection range. She also felt the thud through her flight seat as the two plasma guns deployed on their pylons. Two seconds later the first recon drone disappeared from the plot incinerated by two plasma bolts. "Alpha Uniform,
we have you on visual. Over." Jeannette hit the landing site icon on her display and told the autopilot "Max descent rate." Her stomach lurched towards her throat as the Roton dropped out of the sky and moments later reversed direction as the rotor tip rockets fired to lower the Ouragan gently to the ground as the landing feet deployed. Leaving Rabea to monitor the tac display she cycled through the external camera views watching the Paras running for the loading ramp carrying their wounded with them while the rear guard deployed at the edge of the clearing. "Alpha Uniform
to Tango Delta, we're taking ground fire here preparing to withdraw in
30." The external cameras showed Jeannette the port plasma gun rapid firing towards the tree line. The plasma bolts splashed into the edge of the forest over the heads of the retreating Paras. Red glowing plaser cartridges cascaded onto the ground below the gun causing the mat of grass-vine to smoulder. Splitting her view to bring up flight ops. Jeannette instructed the autopilot to spin up the rotor ready for a quick liftoff. "Incoming mortar
rounds!" Rabea announced, the pitch of her voice rising with the tension. From the tip of
the Roton's nose the laser mirror tracked round towards the approaching
bombs, invisible beams stabbed out. The roton rocked as the final mortar bomb exploded 30 metres away. Jeannette switched to the status display - no red lights, a couple of ambers on the primary APU. "We're all aboard." came Mejdoub's voice on the internal comm. Jeannette grinned and hit the commit button on her ops display. The angle of attack of the roton's rotor blades tilted up and bit the air throwing the Ouragan into the air and away from the Elysian forest and the grenouilles. The roton climbed into the cloudy sky but just as Jeannette began to relax the SAM launch alarm began to chime and her display automatically switched to tac mode. "Rabea make sure the guns are back in PD mode." Jeannette called up the counter-measures program and watched the display as the EW focussed on the incoming missiles and the dispensers began to release flares and decoys. Despite the best efforts of the system only two of the SAMs were distracted and the two others continued to bore in - the roton was a big target and not capable of evasive manoeuvres. Feeling useless, and very vulnerable, she watched as the Ouragan's radar's locked on to the missiles and, as they came into range, engaged them with the two plasma guns. "Splash two vampires." breathed Rabea as the icons for the final two missiles disappeared from the display. The roton continued it's climb to orbit, otherwise unmolested, leaving the forest below to the attentions of the orbital KE strikes. The grenouilles however had quickly dispersed once they had failed to prevent the Ouragan's rescue mission and most of them evaded the retaliation. DevelopmentGunner-Long have produced Rotons, under license from FSI, for several decades and the GLR-GA, MU and MT models represent the second generation to find service with various militaries. The first generation of vehicles were simply militarisation of existing FSI models. Typically FSI would supply the airframe and rotors to which Gunner-Long would fit military standard avionics and comms. Depending upon the customer's requirements various countermeasures were also fitted. The second generation of Gunner-Long rotons however are much more distinct from their civilian cousins although they continue to share many common features. GLR-GA Ouragan and GLR-MU CycloneThe GLR-GA (Ground Assault) and MU (Military Utility) models were developed as part of a joint programme with FSI. The aim of the programme (known as Sycamore) was to produce a common core design which could be adapted to both military and civilian uses while allowing a far greater degree of adaptability than the previous military conversions of civilian models. Sycamore Project Airframe and Rotor |
Above Sycamore Project Schematic showing location of common systems. The Sycamore programme commenced in 2278 and by 2281 the core design (which was based on the evolution of the FSI HL-67D roton) had been finalised and tested in software. With the completion of the Sycamore design the two companies continued separate development of the military and civilian versions. FSI launched their Sycamore variant as the HL-90 in 2289. Gunner-Long also continued to develop the Sycamore design however the unique nature of rotons meant that the process had a number of novel constraints.
In addition the small anticipated production run required that, where possible, components and systems had to be off-the-shelf to minimise development costs. Weapon and Sensor SystemsThe Gunner-Long engineers' and designers' answer to the design conundrum was the combination of three existing weapons systems with the roton airframe.
The Hoplite system was mounted in the roton's nose with the phased array panels incorporated in the nose cone. The PD laser was therefore able to engage any targets threatening the roton from above the plane of the rotors with virtually no additional modifications. Two Scythian plasma gun systems were mounted on retractable pylons on opposite sides of the the main body, below the rotors, to give the roton a ground attack capability in all aspects below the plane of the rotor blades. It was impossible to mount the systems externally (as is the case on the X-Wing) due to the very high air speeds and temperatures experienced during reentry. Two weapons were required to cover all possible angles of attack. Each weapon was supplied by a 1000 round capacity cassette of plaser cells. The detection and countermeasures suites from the Longview AEW drone were also installed in the main fuselage, below the rotor, incorporating detector arrays in the skin giving the roton excellent detection capabilities below the plane of the rotor. |
Above Ouragan GLR-GA Schemtic showing location of primary weapon and sensor systems. Courtesy of Gunner-Long Public Relations. Control and Communications SystemsTriply redundant fly-by-light control systems and hardened optical data buses were installed. A range of encrypted comms equipment was also included giving the roton the ability to maintain contact over orbital distances and to integrate with space, atmospheric and ground forces data nets. The precise nature of the comms equipment was obviously dependent upon the customer however the roton's comms infrastructure was designed to operate with a wide variety of systems. Standard navigation packages (GPS, Inertial, Dead Reckoning) were also fitted to the flight computers. While neither crew member normally had very high task loadings simulations indicated that a single pilot would be unable to manage both flight and weapons control in the event of battle damage. The roton was therefore configured for dual control - pilot/commander and co-pilot/gunner. The standard physical roton controls were combined with two copies of the Scythian X-Wing (a single seat vehicle) virtual cockpit to provide access to the roton's flight information, equipment status, sensor information and tactical data . Ancillary SystemsTwo small MHD Turbines were fitted as redundant auxiliary power units (APU) for the weapons and sensor systems while power for the roton's flight systems was supplied by dual fuel cells as part of the core sycamore design. Self-healing fuel tankage and pipe work were also provided for the four systems requiring it.
Independent life support systems were provided for the crew and passengers giving a shirt sleeve environment in both the cockpit and cargo hold. The crew system was rated at 350 man hours continuous usage (7 days for two crew) while the cargo system was rated for 2000 man hours. Both systems included attachment points in the hold for the provision of addition life support consumables if extended duration operation was required. The crew cabin was fitted with a single person airlock and standard docking port. The cargo bay's docking hatch had no airlock but was fitted with attachment points for an airlock both internally and externally. The cargo hatch also had an extendible ramp to allow foot and vehicle access to the cargo bay without the need for any external facilities. The cargo hold itself included attachment points for various items of cargo handling equipment. |
Above Ouragan GLR-GA (left) and Tourbillon GLR-MT (right) rotons hovering in close formation. The rotons are equidistant from the camera so the image gives a good indication of the relative size of two models. The image was taken at the 2301 Mirambeau Air Show during the MSIF EdI display. Note that both vehicles have cargo bay doors and cockpit shields open following an earlier demonstration of RPV launches. Courtesy of MSIF Media Ops. The main body is cylindrical in form with an aerodynamic nose cone and a slightly flared base. The body had to contain all the Roton's equipment as external stores (weapons, fuel, sensors etc.) would be damaged by the high airspeeds and temperatures of reentry. The fuselage is a monocoque design (that is to say the strength is provided by the fuselage shell rather than by an internal framework) optimised for a vertical load path and constructed of low radar visibility materials (the civilian version of course used standard aerospace composites). Propulsion is provided by a horizontal rotor (or rotors), each blade tipped with a rocket motor. The blades are mounted on a magnetic bearing at the base of the nose cone. The main body of the Roton is prevented from rotating by redundant radial rocket motors. The tendency for counter-rotation is much less on the roton than a helicopter as there is no transfer of rotational motion between the rotor and the main body as this is provided by the blade tip rockets. In theory only vertical motion is transferred via the bearing, although in practice there is some transfer of rotation that has to be compensated for. |
Above Roton landed on the Tiranean moon Europos. Image was taken during a MSIF training exercise and shows a Cyclone roton with the cargo bay door open and ramp deployed. Note that the rotor blades are highly piched (actually only 20 degrees from vertical). This allows the roton to direct the bulk of its rocket thrust vertically. Picture Courtesy of MSIF Media Ops. During takeoff and atmospheric flight the blade tip rockets power the rotation of the rotor and the blades provide lift, in the same manner as the blades on a helicopter. In vacuum the blades are tilted so that the rockets are almost vertical to provide a thrust along the axis of the Roton. The slight angle is required to maintain the rotation of the rotor as this provides the means (centripetal force) to pump the propellant from the tanks in the main fuselage, through the body of the blades, to the blade tip rockets. This arrangement means that the roton does not require the expensive, heavy and difficult to maintain turbo pumps and pressurised fuel tanks found on other forms of interface vehicle. The roton's ability to operate in a vacuum and to land vertically also means that it is capable of landing and taking off from airless worlds (unlike equivalent space planes). |