Glenn WATERS's 'Berkut 360'
Status: first ever Berkut kitplane built
Type: experimental kit-built canard pusher
Powerplant: 1 x Lycoming IO-360
Significant date: 1999
The prototype Berkut was completed in the summer of 1991 and shown at Oshkosh. Orders were taken for kits a year later at Oshkosh 1992, and deliveries began in January 1993. The first kit went to Glenn Waters in the United Kingdom. At Oshkosh 1992, Waters decided he wanted to build a Berkut. At the time Waters decided to build a Berkut, the prototype had flown about one year and had approximately 200 hours on it. If the design had had 2000 total hours, the PFA would have approved the design by examining the kit and relying on the in-service time on the fleet, noting any problems or trends within the design-particularly strength and aerodynamic characteristics. The responsibility of meeting the requests of the PEA engineers lies with the builder, not the kit manufacturer, although cooperation with the kit manufacturer is absolutely necessary to meet the requirements set forth by the PFA.
Waters installed a stock 180-hp Lycoming in his Berkut 360 as a requirement of the Popular Flying Association (or PFA, kind of a cross between EAA and FAA). In this configuration, the plane fit the allowable envelope for homebuilts with the PFA (the UK's equivalent of both the EAA and FAA): under 2000 pounds gross weight and less than 250 hp (with the Lycoming IO-360). He then went to the PFA to obtain approval for the airplane. Since the Berkut evolved from a Rutan design familiar to the PFA, approval to purchase a kit was obtained.
When Waters started his Berkut, John Tempest, the deputy chief engineer of the PFA, began a comprehensive study of the design compared to the Long-EZ. A set of plans, a video, magazine articles and any other information available on the Berkut was provided to the PFA. It then determined there were a few areas of significant difference between the Berkut and the Long-EZ and commissioned a study of the Berkut in these areas. Structural analysis of the landing gear, strake and midsection spar was required. One PFA request required Renaissance Composites to videotape several heavy landings (minimum 3G) of a Berkut to determine how much the gear flexed and if anything in the gear bay moved.
In addition, the PFA required a headrest be placed behind the pilot's head, along with additional warning lights and placards. If the structural analysis or any other requested study of the airplane had not met the standards established by the PFA, Waters would have had to modify the airplane until the PFA was satisfied with the results. Future Berkut builders in the United Kingdom must meet these design standards, most of which were determined through the efforts of Waters. Any proposed changes from these standards by a future builder must be approved by the PFA.
During the building process, Waters had to hire a PFA-approved inspector to document workmanship of the airplane. Since this was the first Berkut, Waters was issued a Project Build Book for a Long-EZ, the closest set of standards held by the PFA for a canard airplane. This book contained 34 different inspections that had to be signed off by an inspector. For instance, when a structure is ready to be closed, it must be inspected. The inspector assigned to Waters' airplane, Graham Singleton, a Long-EZ owner, had to make sure each part of the airplane conformed to the drawings of the airplane and that the construction standard was such that the airplane was structurally sound.
Glenn Waters, who wanted experience on the canard type design, purchased Peter Bruce's VariEze G-WILY. He then sold her back in 1995 to Peter Allen, its original owner, when his Berkut project came to a close. The first parts of the Berkut kit arrived in 1993, and the airplane was a project of five winters, although not five full years, since Waters' work schedule did not allow for building year-round. The biggest challenge Waters faced while building the airplane was finding the composite materials necessary; it required purchasing the materials outside the United Kingdom. When asked if he would ever build another Berkut, Waters said he would, but he would make the airplane a little less complicated. He said, "There's a bit too much froufrou in it." You will see exactly what he is talking about shortly. The best part of the project for him was satisfying the requirements of the PFA and seeing the airplane fly for the first time. Regarding the part he said he would miss least (sweeping all the dust that resulted from sanding the airplane) he said, "I'll bet I had nearly as much time sweeping as I did working on the airplane. "
Over the five years prior to the aircraft's first flight, Waters had been in contact with Ronneberg, discussing the airplane and PFA requests for additional information. When asked what his expectations were prior to actually seeing this Berkut, Ronneburg said, "I expected a Formula One race car, and that's exactly what I got." Prior to the arrival of Ronneberg, Waters had run the engine on the ground and completed a high-speed taxi. Once Ronneberg arrived and picked his jaw off the hangar floor, he checked the airplane thoroughly and was briefed on the systems and avionics in the airplane. The aircraft was pushed outside for an engine runup to check for leaks and avionics function. No leaks or problems were found, and the airplane was cowled for its maiden flight the next day.
Prior to the first flight, Ronneberg was hoping the airplane would fly as well as it looked, but he also knew this is not often the case. With Ronneberg at the controls, Waters watched his airplane take flight on a rare sunny day. According to Ronneberg, after the first flight, " ... the airplane flew with the ball perfectly centered, the roll feel was exactly the same to the right and left, with no slop in the ailerons, and the canard was built perfectly, with no flat spot in the elevator travel." Upon its return, the aircraft was uncowled to check for engine leaks and vibration damage to the cowl. All aircraft systems functioned perfectly. There was a spot on the upper cowling (caused by rubbing of an exhaust stack) that was found, and a stiffer spring was needed on the elevator trim. Both issues were resolved, and two more flights were conducted.
Waters did not vary from the basic Berkut design, but he made a few modifications, such as a fuel bladder as a fuel sump, low-friction bearings in the control system and a centerline duct to provide ram air to the engine. He also moved the landing light to the nose. Waters' attention to detail included a fuel selector that prevented a cover from being closed and also impinged on the aft limits of the mixture and throttle controls when the fuel selector was in the "off' position. Along with this was a retractable step for use when the nosegear is not retracted on the ground. He also installed several devices and features normally found on a Formula One race car, a direct result of his working previously at Lotus.
The test pilot selected by the PFA for Waters' Berkut was retired Royal Air Force test pilot Angus McVitie. The fundamental goal for the test flight is to make sure the airplane is safe and does not have any characteristics that will get the pilot into trouble. The design limits and the flight envelope are thoroughly tested. This includes determining the stall speed, observing the handling characteristics at stall speed and exploring the highspeed end of the envelope by flying the airplane just above Vne and testing for flutter. Upon his return from the test flight, McVitie commented, "I thought the Berkut was a very pleasant airplane to fly. I have not actually completed the evaluation, but we've been through all the corners of the flight-test envelope. [The Berkut] is obviously not a boy's airplane; it is a fairly complex piece of equipment that must be treated properly, and it has natural characteristics that you expect with canards. It was one of the most pleasant canards I've flown." He later added: ""Most of the PFA airplanes I've flown have been very much run-of-the-mill, and this one, the Berkut, is probably the best of the airplanes I've flown under the PFAs auspices. It must be pretty well the top of the heap."
A permit to fly was issued by the CAA as a result of the PFAs complete satisfaction with the design. The PFA set the operating limitations for Waters' Berkut, including the Vne, aerobatic limitations and e.g. limits. Although capable of limited aerobatics, Waters' airplane is not approved for acrobatic flight; his goal was to keep the airplane as clean as possible. The performance specs recorded during the test flights show exactly that. Despite the stock version of the IO-360 engine installed on his very clean, beautiful airplane, Glenn Waters is seeing speeds well in excess of those in the prototype with the bumped-up engine.
Waters's immaculate Berkut, which used a number of technologies from motor sport, later acted as a test bed for aviation use of the Pi data logger. All the instrument readings from the Berkut were logged along with the output of a video camera. Waters used this to assess the stalling characteristics of the canard aircraft. He demonstrated the entire system on his laptop, which linked the recorded GPS data with a Jeppesen FliteMap, video of the airflow breakdown on the canard (with the camera trained on tufts attached to the surface), and gave a graphical indication of air speed, engine speed, acceleration and a range of other flight conditions. This demonstration of the system showed the real advantage of the technology: not only does it records masses of data, but it can provide this data in a visually stimulating and easy-to-read way. It is this which Pi claims sets it apart from other data capture devices.
Since proving the value of the technology on the Berkut, Glenn has been identifying potential uses in other areas of aviation and has settled on the test flying and historic flying sectors as areas where the devices can have the most impact. Glenn Waters is optimistic about this transfer of technology from motor sport to aviation and anticipates a growing market in the corporate and GA sectors as well as flight testing and historic aircraft. The trend towards increasing digitisation of flight systems and displays will make data logging more commonplace and many of the avionics and systems manufacturers may well offer data collection as standard, or options on their regular kit. The lowest-cost system, which can monitor six parameters plus a GPS input, is priced at under £2,000 and appropriate for a high performance homebuilt, which might well have an all-glass cockpit.
Population: 1 [G-REDX] (kit #001, c/n PFA 252-12481)
Specs: similar to the basic
Glenn Waters: from Lotus to Berkut
Glenn Waters' background is not that of an ordinary builder. In the 1970s, Waters worked at Lotus on the Grand Prix racing team. The boss at Lotus was an avid aviator who commissioned Burt Rutan to build a small, two-place canard aircraft that Lotus was intending to manufacture and sell. This did not happen, but as a result, Waters became familiar with the Rutan designs-the VariEze and the Long-EZ-and started his wish list for a Rutan airplane. Twenty years later, he purchased a completed Long-EZ, which he owned until 1996. Waters is a private pilot with approximately 430 hours.
All of Waters' professional life has involved motor sports. He began at Lotus on Formula 11 cars and later, spent nine years associated with the Grand Prix team. He was also involved with Toyota, overseeing the Le Mans program and domestic motor sports at the Formula III level. He is still involved in the motor sports industry, but not as much as before. With a background in motor sports, the jump to building an airplane was not a difficult one. Many construction techniques were similar, particularly working with composites. His involvement with motor sports also gave him numerous contacts for various components he wanted incorporated into the Berkut.