B-25 Mitchell "Briefing Time"
By Andrew Herd (28 February 2003)
he B-25 was assured of its place in the heart of the American public the moment Doolittle's bombardier set his cross-hairs over downtown Tokyo, yet even if that mission had never happened, it would be remembered fondly by thousands of aircrew. The B-25 was a well designed, easy handling plane that was built in greater numbers than any other US twin, and it proved to be about as versatile as an aircraft can get. B-25s served in every operational theater and yet the hull had unpromising beginnings in the failed NA-40 design and a rushed wartime contract that allowed virtually no time for development.
Few aircraft can have had such a short genesis. When the Army Air Corps sent out invitations to design a medium twin bomber on 25th January 1939, North American's engineers took only 40 days to draw up plans for the hull that became the B-25. The crashed NA-40 contributed its tricycle landing gear, a twin tail was selected because of the greater field of fire it allowed astern and various engine combinations were specified, including powerplants from Wright and Pratt & Whitney. In this pick-and-mix state, the design went to the AAC and such was its promise that it was chosen, along with a second plane from Martin, that became the B-26. On September 20th, 1939, North American received an order for 184 aircraft and production began.
The B-25 had the rare distinction for the time of being ordered into manufacturing straight from the drawing board, after wind tunnel testing using scale models. As the original design stood, the plane had twin 1650 hp Wright Cyclones, driving Hamilton Standard Hydromatic three blade props which were nearly thirteen feet in diameter. With a crew of five - pilot, co-pilot, bombardier, radio-operator and gunner - it was calculated that speeds of more than 300 mph were possible. Needless to say, fitting a crew of five and 3600 pounds of bombs into a relatively small fuselage meant that space was restricted and crawlways were installed to give access to the nose and tail.
The first production B-25s were well received, not least because they could be put down in as little as 3000 feet and flew the approach at around 110 mph, which was good by comparison with the B-26. The one fault that surfaced was lack of directional stability and this was fixed in the next production batch by reducing the wing dihedral outboard of the nacelles. As a result, only the first nine B-25s had constant dihedral, all the subsequent models having the gull wing which was so characteristic of the aircraft.
With the outbreak of war in Europe, the B-25 was ordered into mass production and, based on feedback from Britain, the design entered a process of constant refinement. It quickly became clear that fast though it was, the B-25 was no match for the new generation of German fighters, so its relatively light armament was replaced by electrically operated upper and lower turrets carrying twin fifties - the upper turret being fired directly, the lower operated via a periscope.
The B-25 gained lasting fame shortly after America's entry into the war, with a daring attack on Japan. The Doolittle raid was carried out in B-25Bs with the lower turrets removed to save weight, increased internal fuel and dummy .50s in the tail. So equipped, the planes were hoisted aboard USS Hornet, took off at sea and flew 800 miles to their target, which they successfully bombed at only 1500 feet. Although surprise was virtually complete, all the planes were lost due to fuel shortages and bad weather, though most of the crews were saved. Though the damage to Tokyo might have been slight, the boost to Allied morale was enormous.
The next model, the B-25C, had increased armament and external bomb racks, and marked the point at which the plane was named after Brigadier General "Billy" Mitchell, the great champion of strategic air power and a lone voice throughout much of the thirties. 425 of this model served with the RAF as the Mitchell II. Various minor modifications accounted for the next few marques, the B-25G being the most visually distinctive, since it mounted a 75 mm M-4 gun in a solid nose, firing fifteen pound shells. Field modifications backed up the cannon with four nose mounted .50 cal. package guns and this arrangement became official in the B-25H which could also pack a torpedo.
The B-25J reverted to the glass "bomber" nose and was the most widely produced variant. It had a crew of six and could carry 3000 pounds of bombs at up to 285 mph. The hull being inherently adaptable, crews often added extra firepower and later Js carried up to eighteen machine guns. The B-25J was supplied to the RAF, Canada and Brazil during the war. Military use continued into the early sixties and from there numerous B-25s made it onto the civil register as test beds, transports, crop sprayers and air tankers. Then, following a spate of accidents, many planes were taken out of service and left to rot. Some were saved to star in movies like Catch-22 and Hanover Street, while others were rescued by nascent warbird groups like the Confederate Air Force. Though many thousands of B-25s were built, only a handful remain in flying condition nowadays.
"Briefing Time" is a B-25J belonging to the Mid Atlantic Air Museum at Reading Pennsylvania's Regional Airport (Carl A. Spaatz Field - KRDG). The Museum is open seven days a week and its aircraft are regularly seen at airshows and at the Museum's own WWII Weekend. You can join the museum by paying a small annual dues fee which entitles you to full participation in the Museum's activities - but better still, if you buy the CD, you can fly a B-25, while contributing to the cost of keeping an original in the air.
Briefing Time was built at North American's Kansas City plant and delivered to the 12th Air Force, 57th Bomb Wing, 340th Bomb Group, 489th Bomb Squadron with which it served in the North African and Italian campaigns. Post-war the hull was bought by Tallmantz Studios, suppliers of aircraft and stunt pilots to the movie industry, and it served as a support aircraft for Around the World in Eighty Days as well as starring in Catch 22 and War & Remembrance.
Let's take a look.
What we have here is the long awaited B-25 sim from the MAAM-Sim team - long awaited because the last MAAM plane to appear for Flight Simulator was the classic NATS R4D-6, one of the most popular add-ons ever coded for the game. R4D has been through numerous upgrades, the latest being version 7, so the team has serious staying power. There have been some crew changes along the way, but that is inevitable in the fast-moving world of FS design; what seems clear is that we have another classic on our hands and if it doesn't go through at least the same number of versions as R4D has, I, for one, will be the poorer for it, because Briefing Time is at least the equal of the DC3 sim. No, I take that back, it is much better. R4D is impressive and there are simmers who will use nothing else, but its stable mate is definitely going to turn some heads. Visually, it is one of the most impressive packages it has ever been my privilege to review.
The sim was designed by Bill Rambow, Jan Visser, Fred Banting and Rob Young. Bill and Jan should be well known to readers, having been associated with MAAM and the R4D project for many years. Fred is new to the team, but no less familiar, I hope, given his fantastic DHC2 Beaver and Turbo Beaver freeware; and Rob is also an old FS hand, best known perhaps as part of the RealAir Simulations team that did the SF260 we reviewed a while back.
Briefing Time is available as a CD at a cost of $25.00 plus $4.95 for shipping from the MAAM store. A 21 Mb time-limited 'commercial demo' has been uploaded, which has some features disabled, but nonetheless gives a good idea of how the sim performs and if you have any doubt about whether Briefing Time will run on your PC, it would be well worth downloading it. A 34.3 Mb downloadable version is scheduled for release in the near future and will be available from all the usual on-line sources and as if this was not enough, a multimedia source CD with extra material including videos, photos, manuals and historical detail is available for $10.00. The difference between the CD and the download versions is that in addition to the plane itself, the CD contains the manual (also available as a free 17 Mb download), a scanned copy of all 170 pages of the B-25 pilot training manual for the B-25, various videos and a WWII training film about the aircraft. The videos include a some demonstrations of Briefing Time's systems by Russ Strine, MAAM's president - yellow highlights in the manual alert you to when an instructional film clip has been recorded.
I reviewed a preview of the download version. There were no problems with the installation, which was automatic. Reviewing the contents of my hard disk, I found three versions of Briefing Time installed under the \North American\B25J - 'standard', 'medium' and 'light'. These represent progressively stripped down versions of the sim: standard has all the virtual cockpit features; medium lacks the bombardier's and upper gunner's 3D compartments; and light has no virtual cockpit at all. On my test system, which was a 1.7 Ghz PIV, with 512 Mb RAM, an nVidia GeForce4 Ti 200 128, running Windows XP Pro, I could run the standard version, but suffered some carpet-chewingly slow texture loading times when I swapped to spot plane view. I did most of the review running the medium version, but found the sim ran remarkably well with the standard loaded, as long as I didn't crawl around the inside of the plane too much. There are many suggestions about improving the frame rate in the manual, but over the past couple of years I have found the best way of getting FS2002 to sing is to lock the target frame rate to 18, max all the sliders and quit fiddling around.
The 2D panel is at least as good as R4D's and I am sure that many users of the that package will feel completely at home with Briefing Time. The sim loads with the pilot's panel active, but a stack of icons at the bottom far left lets you switch to the co-pilot's panel - as shown above - and to various other subpanels, of which I counted nine in all. The graphics are absolutely diamond sharp, staying that way even when I ran a non 4x3 screen resolution in windowed mode, a test many panels fail with flying colors. All the instruments look believable and like R4D, it is one of the few sims I have seen which makes me forget that I am not staring at a computer screen.
Being in an evil mood, I rang a friend who is a compulsive collector of aviation stuff and asked if he had a B-25 manual - much to my surprise he came round with one that had been printed in 1978 by Aviation Publications! Anyone buying Briefing Time might consider visiting this publisher's website, because as far as I can see, the manual is still available and they do acres of other good stuff. Pausing only to marvel at the quality of the manual, I went straight to the engine start procedure to see how good the sim actually was.
The installation loads six flights in a 'Briefing Time' folder and I flicked through them until I found one that loaded the B-25 with a cold cockpit. This puts the plane in front of the hangar at the Mid Atlantic Air Museum, Carl A. Spaatz Reading Regional Airport, Pennsylvania (KRDG). A pan around the airport was enough to make me realise that you don't get any extra scenery with the B-25 and indeed the MAAM team are seriously keen to hear from an experienced airport designer who can code a package to simulate R4D and Briefing Time's home.
Starting supercharged variable-pitch prop airplanes is something of an art, particularly when they are fifty years old and were ornery to begin with, so we read the checklists through about six times and then we just went ahead and started the thing. Okay, so there were some controls missing, but that is inevitable given the limitations of FS2002 and on the whole, I think the developers made the right choices about what was in and what was out. Starting the plane like this is a good way of finding your way around the panels and not only is there a detailed section on how to do it in the sim manual, Russ Strine demonstrates the procedures on one of the videos. Getting those big radials cranked up involves skipping around the 2D panels like a wild thing and it sure does make you appreciate the icon stacks, because at one stage you have to swap from left to right seats - and that is in addition to popping up almost every other panel in the sim. But once you get the hang of them, the procedures aren't so different from a modern aircraft, so if you have any flying time in a twin, you will be at least partially at home and there is always the old Ctrl-E default startup if all else fails.
Looking at the panels that are supplied with Briefing Time does make me wonder how it is that other developers get away with charging similar prices for substandard graphics. In this age of digital photography, if it is possible to gain access to an aircraft, a developer with even a passing knowledge of PhotoShop should be able to turn out a convincing digital image for use as a panel background. The fact that the proceeds from Briefing Time sales are going toward keeping several rare airplanes in the air rather than being taken as profit by the developers makes the quality of this sim even more impressive - just shows how dedicated some folk can be. So far, MAAM's flight simulation projects have raised over $100,000 for the museum and if they continue to be successful, there is every prospect of more simulations of a similar quality appearing.
In addition to the main 2D panels, there are left and right IFR views, like the one which shows me skidding my way around a turn here and there are many sub-panels as shown in the screen shot above. Do note that the sub-panels have been painstakingly edited so that they 'fit' with the main panel when they are visible and I have completely destroyed the effect by moving 'em around to fit as many on a single screen as possible! The instrumentation will look a trifle odd to spam-can aviators, though long familiarity with Cessnas of a certain age makes an airspeed indicator calibrated in miles per hour seem like an old friend (out of the four aircraft I have flown in the last six weeks, three used mph and only one used knots...) You get a remote reading compass indicator, which was a secondary instrument used to make turning easier in combat situations - it is real easy to forget that you turn 'away' from the heading you want on a whisky compass, especially if there is flak rattling off the fuselage. Then there is an early radar altimeter, which has to be activated by clicking the ON switch with the mouse and also has to be switched between high and low ranges. In reality this instrument was the height of sophistication at the time and saved many lives on low level bombing runs. There is a LORAN system, which has been programmed to give DME readout in the sim, because FS doesn't support LORAN - which is being phased out anyway.
Next, you get a radio compass, which is nothing other than our old friend, the ADF, but with a fixed card. I have flown a plane with such an instrument and spent ages trying to work out where the knob had gone to, before it dawned on me that there wasn't one. Radio compass/ADF navigation is an art in itself - the one thing you mustn't do is just point the needle at the beacon and fly it, because any kind of crosswind will result in your flying a beautifully curved course and the controllers will laugh themselves to death. There is also a pilot's direction indicator (PDI) which was used by the bombardier to tell the pilot which way to go, but has been wired up as a class of a VOR indicator in the sim. This is the one programming decision I would dispute, because it surely doesn't work anything like a VOR is intended to - the way the code works, once you have NAV1 tuned and a TO radial selected, the PDI needle points directly to the beacon, assuming it isn't more than about 45 degrees off to one side. Strange, but it does mean that the gauge ain't wasted.
Then there is the VC, or should I say, VI, because Briefing Time has an extensive virtual interior if you use the standard version, running from the bombardier's station as far back as the rear of the upper gun compartment. This is where I am going to have to eat my words about VCs, because the coding in this area leaves the other VCs I have seen in the dust. One of the most interesting pieces of the manual is the place where Jan Visser talks about the design of the plane's internal and external models - the control quadrant and the Norden bombsight between them use up 2500 polygons! But one look at the screen shot alongside here should be enough to convince you that this is a seriously complex plane and if you load the standard version, it is possible to 'wander' around within it and see similar levels of detail in all the different crew positions if you shift the eyepoint. It looks almost real and the blockiness that I have assumed had to be taken for granted in FS2002 VCs is almost completely absent, which has made me reassess some other designers' work.
One of the best decisions the team has made (apart from taking on this project together in the first place) is to supply 2D cockpit views as well as 3D ones. It is becoming common for packages to be supplied with 3D views on looking in any direction other than forward from the left seat and while it saves space in the distribution and cuts down editing time, it is definitely nicer to keep the views consistent. Moving back to the VC, one of the most impressive things about it is its crispness of focus and early on I actually had trouble working out whether I was looking at the 2D panel or the VC. The 3D panel is impressively bright compared to what we have come to expect and although dark VCs seem to be a common problem, I would be fascinated to hear how the team got around the problem.
Rob Young's flight model seems to be pretty good. I haven't a clue what a B-25 feels like to fly, but the sim seems to be ballpark right and the team had free access to pilots with hundreds of hours experience on the real thing, so I would be amazed if it wasn't correct. Takeoff and landing behavior is very realistic, without any abrupt lifting of the nose wheel and with what feels like very proper handling at the flare, an area where many flight models utterly fail to deliver. In addition, asymmetric power is very well modelled - the minimum controllable airspeed on a real B-25 was 140 mph on one engine. If the airspeed went below that, yaw became a serious problem; which meant that the only way to fly an approach with a dead engine was to wind on full rudder trim and fly with the dead engine high. The one thing the flight model doesn't do - something which is very hard to reproduce in Flight Simulator anyway - is give the impression of how much it is necessary to push the nose down on a powerful plane like this as airspeed builds up in the cruise and the wing generates more lift. The result is that Briefing Time, like all larger and more powerful aircraft, feels lighter on the controls than it probably should be, but there doesn't appear to be any way around this. Incidentally, you can fly the plane from the bombardier's position, which is entertaining at low level, especially somewhere like the Grand Canyon.
In all the excitement, I forgot to talk about the visual model - trouble is that it is too easy to get carried away about that cockpit. Briefing Time is a Gmax design and the plane is about as detailed as you can get in FS2002 and still be able to run it on a PC that you and I might possess. The textures are sharp and the transparencies feature reflections and there is a full complement of animations - including an opening pilot's window, as shown in the screen shot here. Hit shift-W and "Bus" Taylor slides the glass and rests his arm nonchalantly on the sill - just the the thing for waiting endlessly on the hold in hot weather while an incoming 757 establishes on the localiser. Shift-E opens the forward crew hatch, the slash key opens the bomb doors to show two full racks and the cowl flaps open with ctrl-shift-V and close with ctrl-shift-C, though you can also use the levers in the cockpit.
I guess some users might ask why there is only a single livery, but this is a simulation of a single plane, one of only three B-25s still in the air, as far as I am aware. Yep, it sure would have been nice to have an all metal paint, or a post war exec transport (as many of the survivors became) but the raison d'etre of this sim is to raise money to keep historic aircraft flying so that people like you and I can go see them, hopefully for many seasons to come. Supplying the single livery is a good way of reminding us all why the package was coded in the first place, but Bill Rambow tells me that Jan Visser going to do some different liveries and maybe even a solid nose B-25H. The first of these will be the bare metal "Panchito", a frequent show-mate of Briefing Time's, which can be glimpsed on the Doolittle Raid re-enactment video on the B-25 multimedia CD (and while I am on the subject, Jan is also doing some bare metal liveries for the new version of R4D, so stay tuned). You could say it is in our interests to reach for our credit cards, because if we don't, then the skies will be that much the poorer for it, MAAM might reconsider the idea of letting FS developers have unrestricted access to its planes and we would end up being denied such superb software. Briefing Time comes from a team that has a long tradition of sticking with a package and upgrading it as each new version of Flight Simulator is released, so the chances are that you will be reading a review of version 2.0 a couple of years from now - and version 3.0 after that.
The sound set was recorded from Briefing Time itself, so it is about as genuine a set of noises as you are likely to hear in FS2002. You get flap and gear callouts from the co-pilot and high quality recording without any noticeable cycling, with good balance between cockpit and engine levels. Real B-25s make a noise like thunder and while your neighbors may not thank you for it, it is worth turning the volume up all the way just one time to get a feel for what those Cyclones sounded like on full chat.
It is hard to criticise this package - the only bugs I could find were already mentioned in the manual and as a warbird the sim is out there in a class of its own (apart maybe from R4D). You just don't see many planes done this well, regardless of which sim you happen to choose to fly with. The one problem many potential users face is that the visual model is very, very complex and therefore very demanding. The developers don't actually specify a minimum system spec, beyond a machine that can run FS2002 at adequate frame rates. Since my email often contains messages from users who have trouble running add-ons on marginal machines with non-standard setups, I am going to go a little further and reiterate that before you think of buying Briefing Time, you should download the demo and check it out first. If that gives you acceptable frame rates, then go ahead, but given that I suffered glutinously slow texture loading on the visual model from time to time, I would suggest that the absolute lower limit for even considering running the sim is a 1 Ghz PIV and that you should only expect to be able to run the "light" aircraft model on such a system. With a 1.5 Ghz PC and adequate RAM, you should be able to run the "medium" model, and with anything faster than that, the "standard" plane should be OK.
And that being said, this is most certainly one to go on the list. They don't really do add-ons any better than this and even if you don't like warbirds, the package is such good fun you will almost certainly enjoy it. And besides, instead of putting money straight into a developer's pocket, you will be helping keep an important piece of aviation history in the air.Andrew Herd
Visit the Mid Atlantic Air Museum to order your own copy