• Pilatus PC-6 Porter

    Pilatus Porter PC-6 B2-H2 for FS2000 Pro

    Developed by Jim Goldman, Yannick Lavigne, Steve Small, Fred Banting, Marco Rensen

    By Andrew Herd (1 December 2000)

    The Pilatus Porter must be the ugliest aeroplane ever to see the light of day. The airframe appears to have been made from sheet steel by shipyard apprentices, the tail is a huge slab of metal pointing defiantly at the sky, and the nose is an aesthetic disaster. The first time I saw one I remember thinking, 'What the hell is this?' and yet the Porter does have a strange attraction, born of its utilitarian nature.

    There are several versions of the Porter available for Flight Simulator, but no-one has captured its spirit better than this sim - if you are prepared to indulge in a 24 Mb download, two planes and panel are yours for free [fsdpc601.zip]. There is even a basic install routine that should enable the most technically non-savvy simmers to install the package.

    The PC-6 first saw the light of day in 1959 (a good year, so did I) and 523 have been built to date, of which nearly 300 are still in service. The majority are used for parachuting and military duties, but being the workhorse it is, the PC-6 is used just about anywhere a tough plane is needed. Amazingly enough, for such a venerable airframe, the Porter is still in production, with good reason, because an experienced pilot can land a fully loaded aircraft in just over 400 feet after making the sort of approach that makes most fairground rides look tame.

    As originally produced, the PC-6 had a 340 hp Lycoming engine, but this was quickly replaced with a more powerful Turbomeca Astazou II E turboprop engine rated at 573 hp. In its turn, the Turbomeca was ousted by the Pratt & Whitney PT6A-6A, which produced less power, but had the advantage of phenomenal reliability. The vast majority of Porters were built with this engine, although 71 were given a Garrett AiResearch TPE-331-25D turboprop.

    Both the Porters simulate included in this package are the wheeled version, but if you travel enough you will see variants on skis, floatplanes, amphibians and long range planes like the second one in the package. This aircraft really will go anywhere, and it makes a fitting stablemate to the DHC-2 Beaver [beaver7.zip], which performs similar duties in the sort of places no airplane should really ever go.

    So what about the FS2000 aircraft? Well, as we have learned to expect from other products by members of this team, it is absolutely outstanding. Personally, I reckon this crew could make a garbage dump attractive to fly, and if anything, their PC-6 is proof that their output gets better and better. I defy you not to be impressed from the moment the plane first loads and you find yourself staring - gawping - at Yannick and Fred's panel. This is one seriously great panel, from the bitmap right down to the reflections on the instrument glasses. Even the virtual cockpit; one of my pet hates, is attractive and a look towards the rear of the plane reveals just what a hard life it has had. This is a panel that makes you want to go and delete every single other aircraft you have ever installed from your hard disk and never fly them again. There are no fancy instruments here and the avionics fit is fairly conservative: besides the real basics you get two NAV radios, an ADF and an autopilot. If you are prepared to go to the trouble of downloading it, the panel has a bitmap in place ready to accept Alain Capt's ACS-GPS, but installing will probably be slightly too technical for many users. No matter, because this plane is made to fly with two nails stuck in the cowling as your only navigational aid, and you will only spoil it if you make things too easy for yourself.

    The externals are very fine, with full moving parts and a transparent cockpit. The slab-sidedness of the original is well captured and the Porter looks as unlikely in simulation as it does in reality. Here we run into our first problem, which is a 'feature' of FS2000 and something that the developers could do very little about. For some unknown reason, Microsoft have chosen to base the FS2000 Pro turboprop model on a jet thrust source, rather than a propellor. The result is that there is no torque effect and some of the characteristics of the real PC-6, like the sharp pull to the right when the throttle is opened on the ground, can't be modelled correctly. This does have its plus points, because it also means that the aircraft isn't vulnerable to the annoying P-factor bug in FS2000 which causes many aircraft to roll very slowly to the left, requiring constant adjustments of the ailerons in level flight. For all that, the team have captured the flight dynamics of the Porter almost perfectly, thanks to the efforts of Steve Small, the doyen of .air file developers. The defining characteristic of the PC-6 is its handling at low airspeeds and this is captured extraordinarily well; with the result that you really can keep flying all the way down to 38 knots. And as the manual suggests, you can pull off all sorts of stunts with this plane, including the classic trick of whacking on full revs, rolling with the stick held back and literally pivoting it off the ground by rotating on the tailwheel. Another thing that will give you hours of mindless entertainment is watching the 'hanging' landing gear take up the weight of the aircraft on touchdown - just try a landing in spot view to see what I mean.

    The only criticism of any importance I have to make is the fact that the sound set is rather low key. One things Porters have never been is quiet; they make a hell of a noise, in my experience, thanks to the enormous prop they pack up front. On my set up this one could sneak up behind you and you would never notice it coming. Even with the volume turned right up I don't think it was anywhere near loud enough, however, I am assured by Yannick Lavigne that his neighbor has personally come around to ask him where the noise is coming from, so maybe I just need better speakers!

    The first flight I made with the plane was from Bex (LSGB) to Innsbruck (LOWI). I chose some filthy weather to fly in and it is only fair that you should share it too, so I have made the files available here [bex_flight.zip].

    I have saved the flight at the moment where you should begin your descent, 30 miles from Innsbruck, about 19 miles out from KPT VOR. I can reassure you that while the weather is lovely at 18,000 feet, it ain't so good nearer to terra firma and this is not the world's easiest approach, given that Innsbruck lies deep in a valley, with hills rising on all sides, some to 11,000 feet. FS2000 doesn't exactly help matters by omitting some of the navaids necessary to fly the approach, and the ones which are available aren't that easy to pick up from this side of the mountains. There is an ILS on runway 26, but that sort of thing is for wimps, so I pretended it wasn't working. In the end, I executed the approach by ignoring the plate (this is a simulation after all!) tuning the INN NBD on 420 and commencing a descent to 11000. The destination remains hidden until almost the last moment, and the most interesting way of making the approach is to head for a valley running to the right of the course to the NDB - this should become clearly apparent as you near the ground. Once you have identified the valley, which runs at right angles to the Innsbruck approach, bearing about 350 degrees, descend to 8000 feet (the valley floor is at 5000) and be glad you aren't doing this for real, because conditions are somewhat marginal. At the end of the valley, hang a left and fly down the beam until you can do a visual approach. Don't forget that the threshold elevation is at 1890 feet and DO NOT UNDER ANY CIRCUMSTANCES do what I did on finals and cut the throttle right back. The Porter responded by developing a startling sink rate and I piled in about a hundred yards short.

    At a loss to understand how I had managed to stall a STOL aircraft, I eventually resorted to reading the manual, the sort of thing I which I would normally avoid under any circumstances. It was an education to say the least. The PC-6 is not a difficult plane to fly under normal conditions, but the team have chosen to accurately model the ability of this plane to use the beta range of thrust in flight. In brief, the beta range sets the prop to +30 degrees of blade angle and this generates a substantial reverse thrust component. Needless to say, this is not encouraged in the flight manual, but accomplished pilots occasionally use it in extreme conditions. The screenshots give an idea of the sort of descent attitude which is possible - if you check the larger jpgs you will see that the aircraft only has 90 knots on the clock, which isn't bad for a nearly vertical dive with the pilots hanging in their belts (I presume that in real life you make sure there are no unsecured 60 gallon oil drums in back and warn the passengers before you pull this stunt). Just remember to advance the throttle as you pull out, or there will be an uncomfortable decay in your airspeed.

    In the simulation, the beta range is called when the throttle is retarded to idle. Used propertly, this enables you to clear a high obstacle and then make an almost vertical descent at relatively low speed afterward, without any need to use flaps. Used improperly, it causes you to pile up just short of the numbers at small Austrian ski resorts. Looking back on it, I did wonder why the pitch warning and the reverse lamps came on together - the programmers have helpfully enabled this combination to warn you that you have gone into the beta range. So don't chop the throttle, huh?

    Now for the frame rates.

    I ran the tests in clear skies. Both machines were running Windows 98 second edition, MS Flight Simulator 2000 professional edition, update 2b applied. Specs: 733: Intel Pentium 733 MHz, 256 Mb RAM, Creative GeForce 2 GTS with 32 Mb RAM; 300: Intel Pentium 300 MHz, 128 Mb RAM, Voodoo 3000 16 Mb RAM.

      733 panel view 733 spot view 300 panel view 300 spot view
    King Air runway 55 26 34 12
    PC-6 runway 48 14 29 6.6
    King Air high 95 32 65 15
    PC-6 high 55 14 45 8
    King Air approach 55 28 30 14.2
    PC-6 approach 49 17 28 7.5

    The bad new is that you will have trouble running this plane in spot view on much less than a 500 MHz machine, and if you add in clouds, there are moments when things will slow up even on that specification. However, the frame rates are acceptable in cockpit view, so as long as you don't spend too much time admiring the hull, you could get away with installing the sim on a 300 MHz Pentium. However, there is a noticeable trend for recent Flight Simulator planes to assume a fast machine, and I suspect the writing is on the wall for anything less than a 466 MHz computer.

    I can't think of anything bad to say about this plane. The last couple of years have been a sort of golden age of freeware for Flight Simulator, and this plane is definitely a part of that tradition. If it wasn't for a slightly quiet sound set, I wouldn't have the slightest grumble. Truly a great sim, download it now and vote it for an award.

    Andrew Herd
    andrew.herd@btconnect.com

    Download the Pilatus PC-6 Porter