• Vans RV7

    FFS Vans RV7 For FS2004

    By Andrew Herd (16 March 2004)

    Once, long ago, back in fifties, a guy called Richard VanGrunsven flew a Cub and a Taylorcraft from the strip on his parents' farm in Oregon while he toiled through high school and an engineering degree. Then he did a tour in the Air Force as a communications officer and joined the base flying club, where he owned a couple of Stits Playboy homebuilts. The first Playboy only lasted a year, after which Van sold it and bought another, which he rebuilt with a 125 hp Lycoming, new canopy and wingtips - but the performance came nowhere near his expectations.

    Most people would have sold that plane too. But Van scratched his head and took a long look at it and then he sat down and designed and built a new pair of aluminium wings which were a huge improvement on the strut-braced wood and rag originals... but even after all that work it still wasn't good enough.

    So Van sold the Stits (by now called the RV-1) and tried some more ideas out, in a process which ended with the design and production of the RV-3, a plane which his company still sells today. The RV-3 embodied all the ideals of Vans' design philosophy, which is to build a plane that does as many things as well as possible. A single seater, the RV-3 would cruise at over 180 mph on only 125 hp and can take off and land in around 120 yards. To date 215 have been built.

    The RV-3 turned a lot of heads, not least because it was one of the few kits available which was built of Duralinium, using the same techniques as the spam can generation of aircraft. Pilots liked what they saw, but everyone wanted a second seat, so Van sharpened his pencil and the RV-4 was the result. The problem was that Vans was virtually a one man operation at the time, so the new plane didn't fly until 1979, eight years after the RV-3 first took wing. The RV-4 was the plane that launched Vans into mass production and more than a thousand kits have been sold, but it has a tandem cockpit and guess what?

    The RV-6 has a side-by side cockpit and it is available in taildragger and trike (RV-6a) versions and a total of 4000 kits have been sold, of which 1750 have been completed to date. But... well you know how people are. Like all its predecessors, the RV-6 is aerobatic, but the airframe isn't designed to accept more than 180 hp and people had seen the future and wanted more.

    As an aside here, one of the intriguing things about Van is that he has designed all these planes to perform really well on relatively low output engines, and yet a proportion of his clients persist in installing the most powerful units they can physically shoehorn in. Every now and then a dry comment on the subject leaks out from the Vans HQ in Aurora, but nonethelss Vans came up with the RV-7/7a, which has more leg room, headroom and payload than the 6 - and it can take up to 200 hp. The big difference between the RV-6 and the 7, from a builder's point of view, is that the RV-7 has a prefabricated main spar and uses 'matched hole' construction. Prior to the introduction of this kit, anyone building a Vans plane (and this goes for the vast majority of other kits on the market) had to use an unwieldy telescopic trellis-like template to work out where to drill the rivet holes in the panels; a nerve-wracking process, since the margin for error is considerable and a single hole in the wrong place can result in a scrapped panel and the loss of dozens of hours of work. Having matched holes saves vast amounts of time, as the structure can be clecoed together - those little silver things sticking out the panel are the clecoes on our RV-9a wing, which uses the same matched hole construction - before being drilled and riveted. Typically, an RV-7 can be completed in around 1400 hours, which is 30% less time than it takes to build an RV-6.

    So far, only 56 RV-7s have been completed, but a glance at the performance figures on the Vans website gives an idea of just what one of these planes can do. With a 200 hp Lycoming and one person on board, you can take off in under a hundred yards, climb at 2500 feet per minute, cruise at over 170 knots, fly 800 nautical miles at up to 25,500 feet, land in 120 yards and still have change left for a burger and a cup of Joe, assuming you did all the work yourself. Oh, and you can do aeros on the way and the stall speed is only 44 knots, so what are you waiting for?

    Despite the remarkable performance that Richard VanGrunsven's designs offer, RVs have had scant attention from the flight simming community. I cannot work out quite why this should be so, other than natural conservatism at work, but a quick search through the file library only comes up with a handful of freeware RV addons. Now, thanks to Flight Factory Simulations, we have a worthy payware RV-7 for only $19.99.

    The addon is available as a 54 Mb download - which means that broadband is more or less essential - the manual is another 10 Mb and there is a good selection of self installing free 32 bit liveries on the site which vary from 6 to 22 Mb each. Before you can make a purchase you need to complete a logon procedure similar to the system used by PSS, but the package is then credited to your account and can be downloaded in full. Installation of the addon is automatic and a standard setup comes with nine liveries ranging from the factory yellow, blue and white, to an eye-smartingly purple plane - which load without any instruments in the panel until you enter a multi-digit personal registration code via the \aircraft\flight factory menu item. The developers have also brought out a CD distribution, in a DVD-style case, for $27.99 domestic and $33.99 international. The CD has all the liveries (dirty and clean, DXT-3 and 32-bit), as well as the Quick Start Guide and the POH

    Checking out my system after the installation was complete, I found a Flight Factory Simulations program group installed, containing an icon for uninstalling the package. I spent some time searching for the manual before I realised that it wasn't part of the default installation, but at 74 pages it is very comprehensive and a credit to FFS - I just wish more developers provided documentation written to the same standard. After a short section covering the registration process, the text goes on to describe the history of Vans Aircraft, gives an overview of the RV-7 and continues with instructions on how to use the panel.

    According to FFS, Vans weren't totally forthcoming about performance data, with the result that a few figures in the manual, like the Va and Vfe are out - for what it is worth, the Va for the RV-7 is 142 mph, which is around 124 knots, whereas the POH quotes 180 knots, while the Vfe is 100 mph, or about 87 knots, while the FFS manual puts it at 100 knots. In the normal course of simming, this doesn't really matter, but in real life RVs are pilot-limited aircraft, which means that you have to treat them with a certain amount of respect - control forces are relatively light and speed builds up fast, so handling the plane the way you might fly a Citabria or a Stearman runs the risk of overstressing the airframe. This sounds crazy, but even with a +6 -3 G design strength, flying a 200 hp RV-7 like the one in the sim must take account of its relatively high power loading; so although it is aerobatic, you cannot enter a maneuver like, for example, a split-S at anywhere near cruising speed, or you will bust Vne and the G-limit on the way out. Vans quote the safe entry speed for this particular figure as 100-110 mph - a world away from the full throttle, aileron roll, stick right back, what's next? that we know so well in Flight Simulator. Non-flying readers may think this a little strange, but the few makes of plane that are stressed for unlimited aerobatics all have lifed main spars - and when their time is up, you effectively have to throw the aircraft away. There are no lifed components in an RV-7, but the payoff is that you have to pay attention to the rules.

    This discussion of limitations leads neatly onto a couple of utilities that FFS provide, in the form of a graphical failures module and the flight analysis/maintenance module. FS2004 already has its own failures system, but the FFS module extends it with a much neater interface and a maintenance module which lets you put right all the damage you have caused. Apart from all the usual instrument failures, if you run the engine over its oil and cylinder head temp limits, wear will begin to accumulate and eventually, after a period of rough running, the pony will quit and you will own a glider. The maintenance module even tracks tire wear and oil usage, so make sure you keep the engine topped up and don't ride the brakes, or it is late nights lying on your back in a pool of icy water in the hangar for you. As if this wasn't enough, the lower left of the maintenance dialog contains a cost summary which will introduce you to the virtual costs of aviation. Believe it or not, you can also adjust the 'rate of weathering' which means that you can choose the speed at which your beautiful clean RV turns into a dirty one (no kidding), and there is even a flight recorder, in the form of a flight analysis gauge. This opens up an interesting possibility, which is that FFS could potentially make ignoring the entry speed in a simulated split-S a problem in the sim, by tracking the relationship between the indicated airspeed, control deflection, G load and the airframe limits - but as it is, the package comes loaded with goodies, so I guess we can hardly ask for more.

    The visual model is neat but not over-detailed. The Rallye I am currently flying lies at one extreme of the way airframes are built and has such large gaps behind the ailerons that pigeons have been known to make nests inside the wing - but Vans has devoted so much attention to drag reduction on their designs that a good paint job on top of the flush riveting can leave a totally smooth airframe. The FFS model has visible rivets, moving control surfaces and an opening canopy, and flexible gear, though you have to be concentrating to see it. You also get some cracking liveries - it may be that the lack of rows of drag-inducing mushroom-headed rivets and uneven wing panel alignment that we take for granted on other planes makes RV owners compensate by choosing outrageous paint schemes. Try this Vans' Air Force link and you will see that the FFS selection is pretty conservative.

    Other than Yaks and Porters, I can't think of another plane which routinely attracts such gaudy liveries, which makes the addon a natural target for repaints. The developers have issued paint kits for their Learjet and Extra 300L, but there isn't one available for the RV-7 yet.

    The flight model gives a good impression of what it is like to fly one of these extraordinary little planes; an experience unlike anything you are likely to have had before. It doesn't matter what engine you put in them, RVs just hurl themselves into the air and then climb at the most phenomenal rate at a steady 90 knots. Typically, RVs climb at around three times the rate of club planes and people who aren't used to the climb angle required instinctively push the nose down, with the result that the plane speeds up - and they find themselves miles away from where they expect to be by the time they reach 2500 feet. Not good if you are near controlled airspace! Though I have not flown an RV-7 with a 200 horse engine, I would have said the sim has this phase of flight and the cruise just right.

    Though you can tour an RV-7, aeros are what they are built for and the sim does as well as can be expected within the confines of what FS2004's flight physics will allow. So while you can't do spins, snap-rolls, or accelerated stalls, just about anything is possible, including sideslips and outside loops, though don't forget that the airframe is not designed for unlimited aerobatics, like a Zlin or an Extra, which means that certain figures, like that outside loop, can take it to the limit. Once again, the danger in an RV is that poor planning can commit you to a maneuver that the airframe cannot safely complete, because there isn't enough drag to keep you out of trouble. In Flight Simulator, of course, the worst experience you are likely to have is a reset (-:

    Two things did strike me as needing a certain amount of improvement: the first is that the constant speed prop slows the plane down more than the flight model would have you believe and flapless landings are possible in a real RV-7 without flying a 1% gradient on the approach; second, although the ground handling is docile by taildragger standards, it isn't that docile. We are seeing a steady trickle of ground-loopable tailwheel planes for FS and it would be nice if this was one of them.

    The 2D panel is based on artwork rather than a photo and it has its good and bad sides. The plus points are that it is clear and switching to the right hand seat view FFS provide is nearly instantaneous on a 3.0 Ghz system; the negatives are that the perspective is a little odd; either the plane has the biggest key ever, or the radios are far too small. The nav/com is a simulation of the excellent Apollo SL30 and you cannot adjust it from the main panel; a popup has to be used instead. This has extremely clear graphics and can be dragged to any size you want, though for some reason the right hand knob is cut in half, but like the real thing it can store and recall multiple frequencies and can not only ID navaids and show which radial you are on, but can display a mini CDI. One snag with the unit is that the fonts don't always catch up with resizes.

    The GTX327 transponder is an upmarket Garmin unit that has three timers in addition to mode C operation. Setting a squawk requires you do no more than type it in and the unit squawks the US VFR code automatically at a single keypress. Very nice and only $3000 new if you want a real one. Other panel popups include a tank selector, engine control panel, various instrument enlargements and a G-meter.

    Frame rates were consistently about a third less than the default 172 gave me in 2D panel mode, which is a relatively high hit for this type of plane, but not unusual. There were no unexplained slow ups and the popups didn't seem to affect performance in any way.

    The VC provides a more realistic perspective than the 2D panel, which, thanks to the limitations of computer screen format, rears up much higher than a real RV panel does. You wouldn't imagine it from looking at the sim, but the standard panel is only about a foot high, but that's FS for you.

    Everything I investigated in the VC was clickable and the radios can be popped up in a window so that you can continue to talk to ATC. Given the nature of the addon, I flew it a lot using the VC and had no problems with it - it is particularly useful if you find yourself having to sideslip off some unwanted height.

    The sound set is okay, though nothing to write home about. RVs are usually quite quiet inside and it is possible to hold a conversation in the cockpit without headphones, so you don't need to turn the volume right up when you are flying this one.

    Verdict? The manual is one of the best bits of the package and anyone who reads it thoroughly will not only end up with a good grasp of how the plane works, but learn all kinds of useful stuff about engine management and the principles of flight, so full marks to whoever wrote it.

    Overall, the package is above average for payware, based partly on the price - under twenty bucks - and the extras. To compete with leading edge payware from developers like Captain Sim and Flight1, the panel graphics would have to be improved and the flight model needs some fine tuning, but until someone comes up with another RV, this is the only game in town. If you want a different perspective on what sport flying is all about, this is where to get it.

    Andrew Herd
    andy@flightsim.com

    Visit the Flight Factory Simulations web site