Bolt From The Blue

Steen Skybolt G-BVXE – 1998 Air Squadron Trophy winner

(From Popular Flying, 11/12 1998, Page 32)

By Ed Hicks
Photography by Ed Hicks and Trevor Reeve

As well as being a play on words, the title of this piece could easily describe how Trevor Reeve felt about the news informing him he was this year’s recipient of the PEA Rally Premier Award, the Air Squadron Trophy for best plans-built aircraft. Having entered his Steen Skybolt for judging out of curiosity — he had not even considered it during his attendance the year before – the news he had won was definitely a ‘bolt from the blue.’

The story of this particular Skybolt had begun a few years before Trevor Reeve became involved with it. PFA project 64-11123 had been started by Trevor Humphries of Littlehamptom. Registering it as G-LISA and getting an exemption from PFA Engineering to fit a 200hp Lycoming, he had proceeded to work keenly on the project. Completing the basic fuselage to the stage where it could stand on its own undercarriage, and getting well underway with the wings, he began to feel that his needs for an aeroplane were changing. A two-seat open-cockpit biplane was no longer going to be suitable. So the project was put up for sale, an advert appearing in an Autumn ’92 issue of Popular Flying requesting ‘sensible offers’.

G-BVXE doing what comes naturally! Photos: Ed Hicks

Conveniently, at the time the advert was placed, another Trevor (Reeve) had decided that open-cockpit aerobatics, with space for a friend, was definitely for him. Opting to build instead of buy, as it promised to be an interesting thing to do, Trevor looked at what was available. Deciding it was the most handsome, he picked the Steen Skybolt. Like any keen plans builder, Trevor was scanning the classifieds in search of useful bits for use in his planned project, when he found Trevor Humphries’ advert.

Deciding it made good sense to consider buying a part-completed project, he arranged to see G-LISA. It was not to be a wasted trip, for by late Autumn 1992 the project had changed hands from one Trevor to another.

Like other purchasers of part-completed projects, Trevor stripped the Skybolt back to its basic structure and started again. Photo: Trevor Reeve

G-BVXE is hauled aloft by a 200hp aerobatic Lycoming, fitted with a four-into-one exhaust system made from a Steen Aero Lab kit. Photo: Trevor Reeve

At the time Trevor bought the Skybolt project, he was flying Tornados for the RAF Therefore, all the components were transported to RAF Coningsby. However, it was only to stay there for five months, as Trevor’s jet-flying took him north to RAF Leuchars. Here, he found a home for the Skybolt in a corner of the Aberdeen, Dundee and St. Andrews University Air Squadron hangar. The luxury of space to spare allowed for storage racks and work benches to surround the major components while they were worked on.

Providing valuable assistance throughout the Skybolt project was friend Sgt. Andy Turnbull, also stationed at Leuchars. An excellent craftsman, Andy understood what standards Trevor was aiming for, and the combination of two heads proved useful in solving any problems as they occurred. This had also been the case while Trevor was at Coningsby, for he was able to gain valuable engineering advice from Sgt. Gordon Smith during the initial stages of the project. From the start, he wanted his finished aircraft to be as corrosion resistant as possible. So the first task was to completely strip the Skybolt to enable him to start from the ground up. The 4130 steel tube frame was retained and re-worked a little, and once re-primed was gradually fitted with new stringers and skinning.

Inside the fuselage is a 24 imp gallon fuel tank (Skybolts can also be fitted with an optional 8.3 imp gallon top wing tank), which keeps a floor-mounted two gallon supply tank filled for when inverted performance is needed. When designing the method by which this tank is retained, Trevor used a similar method to that used in the Shuttleworth Collection Bristol Fighter, which had its oil tank strapped into its fuselage with steel cable.

The 200hp Lycoming, driving a Hartzell constant-speed prop, came with the project and was fitted behind a standard Steen nosebowl. The cowlings, which are made up of four individual pieces, were painted throughout in a light grey two-pack finish and are well supported to help prevent distortion or fatiguecracking. Distributing the oil in unusual attitudes is a Christen inverted oil system. Like the nosebowl, the exhaust system kit was also ordered from Steen Aero Lab. Once cut and assembled, it creates a neat four-into-one setup, which seems to keep the aircraft quieter than some other similar machines.

Trevor Humphries with the partially completed structure of G-LISA. Not long after this was taken, the project passed into the hands of Trevor Reeve. Photo: Trevor Reeve

Fuselage nearly complete, work under way on the wings. Photo: Trevor Reeve

Skybolt rear panel has a simple VFR fit. Photo: Ed Hicks

All systems in this Skybolt were installed with easy maintenance access in mind. It is also possible to remove the aluminium fuselage skinning that runs from the firewall to just behind the rear seat, assisting with internal inspections. Typical of a sport aerobatic biplane, there is very little interior trim, so a visual check on most controls is possible as they run within the fuselage. Each cockpit, finished in a pleasing light grey, has a set of flying controls. However, only P1 in the rear has engine instruments, prop and mixture controls, trim and the King KY96 radio. Draught deflection is courtesy of two curved screens. Within the rear fuselage top deck, behind an upholstered cover, is a baggage compartment with a 30 lb limit.

The undercarriage arrangement was modified by Trevor Humphries. Instead of the standard bungee system, he opted to use a cantilever system similar to that fitted to the Marquart Charger biplane. Trevor Reeve was happy to retain this installation, as it offers a slight drag reduction and looks good. On the ends of the legs are Cleveland wheels and brakes, each assembly faired by spats from Aircraft Spruce and Specialty. Taking charge of the third point duty is a Maule steerable tailwheel. A partially complete set of wings was also included in the project. These were re-worked with new metalwork and when fitted to the fuselage, necessitated the most complex portion of the work, the rigging. Always a situation of measure, check, measure again, Trevor was keen to get it right first time, rather than end up with an out-of-rig aeroplane. As part of this job, making the interplane struts proved to be the most difficult task out of all the work. Flying wires were ordered from Bruntons of Mussleborough. With eighteen wires in total, they represented one of the biggest single costs in the project.

Where covering was necessary, the Poly-Fiber (nee-Stits) process was used. Trevor rated the process and the support from its suppliers, Aircraft Coverings at Henstridge, as excellent. With everything primed and covered, the finish colour of Randolph two-pack Insignia blue was chosen and applied. Besides its new registration, G-BVXE, and the name it carries in memory of one of Trevor’s grandparents, the airframe is otherwise unmarked — Trevor deciding to let the lines of the airframe speak for themselves.

Steen Aero Lab Inc. and the Skybolt

The Skybolt was designed as a two-seat fully aerobatic biplane by Lamar Steen. The first example was built as a class project in the Denver school where Steen was an aerospace teacher. The aircraft made its debut at Oshkosh 1971 and has proved to be a popular design amongst homebuilders around the world, with over 3000 sets of plans sold.

Since 1989, Steen Aero Lab Inc. has been run by Hale Wallace. As one of Steen’s early customers, Wallace had purchased a set of plans and had built two Skybolts, one with 180hp, the other with 260hp. Both were three year projects. Upon taking early retirement from a computer company, Wallace purchased the design rights. After updating the plans with the assistance of Lamar Steen, he now works full time supplying homebuilders with a variety of Skybolt items, varying from plans to wing kits and pre-welded fuselages.

It is rare to find two Skybolts that are alike. This is due to the variety of modifications builders incorporate into their projects. The most common are canopy configurations and powerplants. The former includes open screens, single and dual seat bubbles, while the latter has ranged from Lycomings to Continentals, to Chevy V8’s and radials.

After nearly four years of working in all his spare time, accumulating well beyond the 2000 hours when he stopped counting, the Skybolt was ready to fly. Having been finally inspected by Pete Murray — Trevor’s PFA inspector for the project — engine runs and taxi testing confirmed all was well. So, just after 2100hrs on June the 8th 1996, the Skybolt lifted-off from RAF Leuchars for its first flight. G-BVXE needed very little trimming and has proved to be simple and reliable to operate ever since.

There is only one thing Trevor thinks he would do differently if he was doing it again, and that would be to fit a fixed-pitch prop in place of the constant-speed prop. Originally installed because it came with the project, Trevor now believes he could do without its additional weight and complexity. Otherwise, he’s just going to keep enjoying it as it is. As he now flies 747s for British Airways, the Skybolt has moved to live on a farm strip near Diss in Norfolk.

Trevor would like to thank the various people who helped with an assortment of tasks during construction — he wouldn’t name names just in case he forgot someone. He is also grateful for the help and support he received from his wife and mother. Would he consider building again? If and when he gets around to it, Trevor says he’d probably go for something like a G202. But it would have to be a team project, as he reckons that working with others is all part of the fun.

The author would like to thank Trevor Reeve for his input to this article and for flying the Skybolt for the camera, John Carter for flying his Yak 52 as cameraship and all the helpful staff at Old Buckenham airfield. Thanks too, Barry and Paul.