AVSIM Commercial Aircraft Review AlphaSim SR-71 … · AVSIM Online - Flight Simulation's Number 1 Site! AVSIM Commercial Aircraft Review AlphaSim SR-71 "Blackbird" v2.0 Product Information

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AVSIM Commercial Aircraft Review

AlphaSimSR-71 "Blackbird" v2.0

Product Information

Publisher: AlphaSim

Description: Add-on aircraft.

Download Size: 53 MB

Format: Download

Simulation Type: FSX (SP2)

Reviewed by: Jeff Shyluk AVSIM Senior Staff Reviewer - July 25, 2008

FOREWORD: Often Imitated, Seldom Duplicated

For this review, I got my hands on the exciting new SR-71 Blackbird by AlphaSim. It turns out to be quite a complex aircraft, although that should come as no surprise. After all, this is a re-creation of one of the world's most extreme vehicles, a jet that typically cruises at 80,000 feet and can travel for sustained intervals past Mach 3. In the real world, only elite pilots with many hours of flight experience flew the SR-71 Blackbird. You can get the whole tour of duty starting with this review!

Dangerous, dark, and fearsomely fast, the SR-71 Blackbird has captured the imaginations of aviation enthusiasts like no other aircraft in the history of transportation itself. Despite the fact that the SR-71 is obsolete, its distinctive frame remains in the public consciousness as a pop icon for ultra-modern flight. Even with dozens of famous aircraft surrounding it, the Blackbird grabs your attention first in any museum where it is featured. If its mission wasn't for clandestine political information gathering, it would be considered a work of art. Maybe it is, anyway. It's one of the most striking

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Park a Blackbird and you will attract a crowd. This is one of a handful of

SR-71's on public display. Photo is courtesy of AlphaSim.

vehicles I have ever seen.

It's also one of the most frequently modeled add-ons for Microsoft Flight Simulator. Hunting around on the AVSIM library, I found ten-year-old entries for the Blackbird that go back to FS98. Perhaps there are even earlier sim-incarnations of this aircraft. Every few months or so, either a freeware hobbyist or a payware developer seems intent on cranking out another SR-71.

Where does AlphaSim's effort stand among all of the imitators? Well, I will get into that as best as I can. If you are a die-hard Blackbird fanatic, then you probably have flown a number of the other models already. If you have not yet had the pleasure of strapping yourself into the ejection seat of a "Habu", then you might want to read the history lesson I have prepared:

INTRODUCTION: "Habu" - The Flying Viper

The SR-71 Blackbird was designed in the 1960's primarily to be a high-speed high-altitude photo reconnaissance platform. It was intended to fly higher and faster than any missile that could possibly intercept it. To the credit of the Blackbird crews, no SR-71 has even been shot down, despite an estimated four thousand separate attempts. Documents that have recently been declassified indicate that the SR-71 would cruise best at 80,000 feet altitude at a speed of Mach 3.2. In the real world, this pushes at the boundaries of aviation science. Even in FSX, it's not easy to get a ride that will fly that fast and that high without encountering some troubles along the way.

You take a chance getting up in the morning, crossing the street, or sticking your face in a turbofan.

Onlookers get a close-up look at a Blackbird engine.

Photo is courtesy of AlphaSim

Propulsion systems for the Blackbird are exotic by any standard, and at the time led the cutting edge of space-age technology. Powered by twin J-58 turbojet engines with afterburners, the SR-71 could take off from the ground and fly well into the stratosphere where air is scarce. In fact, for activities that were not considered "short sleeve missions" (i.e. flights that ranged above 50,000 feet), the crew was required to wear sealed pressurized flight suits. The Blackbird had a hull that was largely composed of titanium or titanium-based alloys. This metal was lightweight, strong, and able to withstand the searing heat from atmospheric friction caused by cruising past triple the speed of sound.

The Blackbird was notorious for leaking jet fuel. To save on weight and leaked fuel, most flights took off with partial fuel and then were topped-up in mid-air using friendly tanker aircraft. Incidentally, the AlphaSim SR-71 will allow you to perform in-flight refueling with the help of some fictional custom gauges.

The fuel itself, JP-7, is not extremely volatile, which means that if it was spilled or leaked it could not immediately be ignited by a common heat source. JP-7 absorbs heat well, so that the fuel system in the Blackbird was designed as a large heat sink. When the fuel was to be ignited, it was mixed with a small amount of TEB (triethylborane), which when exposed to air, created a hot, green-tinged explosion.

The Blackbird could cover tremendous distances in a very short time. It was possible for the pilot to take off in the morning in one continent, take pictures over another continent, and return home for dinner. The three primary bases for the SR-71 included Beale AFB in California USA, RAF Mildenhall in England, and Kadena Airbase, Okinawa, Japan. Japanese locals, seeing the SR-71 taking off, nicknamed it "Habu". A habu is a poisonous viper snake in Japan that resembles the front part of the SR-71.

From its three main bases, the SR-71 could conceivably photograph the entire world. Yet the project that began in 1966 was shut down officially in 1998. Space satellite technologies, as well as advances in reconnaissance aircraft including the use of unmanned drones, appear to have made the SR-71 redundant.

INSTALLATION & DOCUMENTATION: Required Reading

AlphaSim provides the SR-71 for FSX as a download of around 52 Mb. The main part of the program is an executable file that automatically installs the Blackbird into your FSX folder. Once installed, you get the aircraft plus a .PDF



The AlphaSim installer for the SR-71 in FSX

manual. I had no problem with the installation process, which was quick and easy.

After installation, the various Blackbirds appear in the Aircraft Menu as graphics depicting the tail number rather than as the traditional thumbnail action shot. The SR-71's closely resemble one another to the civilian eye. Perhaps the easiest way to tell most Blackbirds apart is by looking at their tail numbers. The AlphaSim package comes with eighteen choices, but only seven different aircraft. In the history of the SR-71, some tail numbers were changed for reasons of security, or because the aircraft was re-purposed. As well, AlphaSim provides normal view cockpits as well as cockpits that are enhanced for widescreen monitors, which brings the total of choices up to eighteen.

Instead of thumbnail screenshots, you can choose your Blackbird by its tail number.

I like the manual, which is 57 pages in length. It is written in a clear, easy-to-understand language. As the SR-71 is such an unusual aircraft, the manual does an admirable job of simplifying complicated issues. As well, since the AlphaSim Blackbird really pushes at the edge of what FSX can simulate, the manual also explains how to work around the problems FSX has with the SR-71. The display of speeds past Mach 3 comes to mind, as well as the problem of in-air refueling, and I will look into these issues later in my review.

Another thing I like about the manual is that it shows a satisfactory understanding of the history of the SR-71 Blackbird. Several pages are devoted to the development and historical operation of the Blackbird, and include some striking photographs of the real aircraft. As well, a brief history of each tail number is provided, so that every AlphaSim Blackbird you fly in FSX has its own true story.

The manual also has a clear, comprehensive walk-through of the cockpit systems. Many of the more complicated systems are simplified for FSX; however, the AlphaSim Blackbird is a demanding and complex aircraft to fly. The overview of the cockpit, complete with well-labeled illustrations, provides much-needed baseline information that the sim pilot will require to fly effectively.

Finally, there are the checklists, which are derived from the real-life operations manual. The AlphaSim SR-71 is designed to be flown by the numbers. The checklists allow you to do this. They are, however, simpler than the actual real-world checklists. The simpler checklists allow you to take your Blackbird into the skies much more quickly than a real Air Force pilot who would have to study his or her notes in detail before being allowed into the cockpit. If you like, you can find a copy of the real de-classified SR-71 flight manual and fly the AlphaSim SR-71 by the book.

EXTERIOR MODEL: Beauty Is In The Eye Of The Beholder

Up front, I feel ambivalent about the AlphaSim model for the SR-71. I have seen the real Blackbird up close. Even in retirement, it is an aircraft with a breathtaking visual design. The AlphaSim model is a reasonable effort to capture the almost otherworldly grace of the Blackbird, but I am not convinced that it fully represents the SR-71. Maybe there is a certain "Wow!" factor that's missing when I look at it. I am sure other may see things differently, especially if they are running on computer rigs different from mine. After all, beauty is in the eye of the beholder.



The Blackbird on the ground. The SR-71 cannot start its own engines, and so uses special "start carts" which are included in the AlphaSim model. Also,

there's a boarding ladder for the flight crew. The rest of the hangar is part of AlphaSim's Beale AFB scenery, which is not included with the SR-71.

On the positive side of the ledger, all of the basics in the model seem to be covered. The AlphaSim SR-71's unique fuselage looks like a faithful replica of the real thing. And, like the real aircraft, it looks misplaced while on the ground. A close inspection of the real Blackbird reveals gaping welds, droopy wings, and a fuel tank system that leaks significantly. What the Blackbird needs is speed and altitude, and when it has them, the heat of friction literally seals the welds, lifts the wings, and stops the leaks.

The AlphaSim model features most of the details that are found in the real Blackbird. The complicated system of air intakes looks realistic, and items such as black front wheels and silver rear wheels are not overlooked (the rear wheels are treated to reflect heat, while the front wheels are automatically cooled by the cabin air conditioning, and so do not need to be reflective).

The front landing gear is conventional, while the rear landing gear has silver-coloured wheels.

Since the SR-71 is built to be sleek and fast, there are not many external animations. AlphaSim does their best to include what they can with their aircraft model. The usual items include canopies that open and wheels that retract are functional. Control surfaces include twin rudders and rear-mounted elevons (ailerons for delta-winged aircraft), and they are very lively when they are moving. There are no flaps or spoilers on a SR-71.

Special animations include an animated parachute that deploys as a speed brake instead of spoilers. The parachute can be used repeatedly, which is unrealistic, but it sure helps when you are lining up for refueling with the decidedly sub-sonic KC-135 Stratotanker. Another special animation is the spectacular afterburner exhaust. You can watch the triethylborane (TEB) shot ignite the fuel stream, and then see the afterburners glow. A series of "shock diamonds" (geometric patterns in the afterburner stream) trails in the exhaust like strings of fiery pearls.



The afterburner ignition sequence. Although the actual ignition is rapid, it can take a few seconds for the afterburner to respond to throttle commands, which is realistic.

On the other hand, some animations are removed from the FSX version of the AlphaSim SR-71. Specifically, a supersonic air intake and the main engine spikes no longer animate. In addition, the elevons will not droop after engine shutdown, and the free-floating afterburner vanes are now fixed in position. None of these components are in locations where I would expect to find large primary animations. In all cases except the droop, the part would move as little as an inch or as much as a foot.

Textures are respectable overall, with a few issues that I didn't like. The SR-71 is mostly painted black, but really, there are many variations of grey and subtle colours in the ebony skin. Many of these imperfections, like heat scoring and other stains show up nicely in the AlphaSim model, at least during the day. At night, all of the shades fade to black, and the SR-71 becomes a delta-winged silhouette. Exterior lighting highlights in the AlphaSim SR-71 are nearly non-existent, making the Blackbird very hard to see after the sun goes down.

A close-up, daylight view of the titanium-alloy skin reveals subtle

colours, stains, and scoring. Bump mapping reveals corrugations in the wing as well as flush-mounted rivets. Note the fearsome-looking engine air

intake spike.

DX9 Bloom effects make the SR-71 too shiny by far.

Turning on the Bloom function in FSX results in a shiny Blackbird, which is not realistic. Nearly the entire aircraft is



painted in non-reflective matte paint in real life. Those sim-pilots with DX-10 enabled may have better results with Bloom turned on than I did.

Besides secularity, advanced bump-maps and shading enhance elements of the SR-71 such as the special corrugations on the wings and the alloy patterns on the elevons.

Another problem I had was with a series of fine lines that appeared along some of the Blackbird's seams. Although these lines do not show up very much in screenshots, they are easily evident when the aircraft is in motion. As the AlphaSim model was converted from FS9 to FSX, I would suspect that there might be texture issues at the heart of this problem.

Fine-lined "seams" are apparent throughout the external model. The seams do not show up well in screenshots, but are easily visible in animation. I've used arrows to highlight where these seams can appear.

One look at this picture should tell you why it's important to keep your hands and body inside the cockpit at all times.

I found some ominous stain-like textures on the inside edge of the cockpit canopy that look like fresh blood, perhaps giving a new meaning to the term "texture bleed-through". Again, this is a minor issue, unless you are particular about how bloody your SR-71 should look.

At the beginning of this section, I held some reservations regarding the quality of the textures for the AlphaSim SR-71. I would suggest that the root cause of my doubt lies with the window textures. Not much of the Blackbird is glass. However, the little bits that are made of glass stand out as being unrealistic, to my eye. I feel that the colour of the glass is a shiny sky-blue that looks cartoonish on the AlphaSim SR-71. It's just enough of an effect to keep me thinking that I am looking at a computer model and not a real aircraft. It seems like older-style cockpit glass such as what you would see on earlier FS9 models.

Sim pilots can look at the screenshots of the AlphaSim SR-71 and judge for themselves how realistic and appealing the external model is. I think it needs a little more work in places, but that it's a competent model overall.

COCKPITS: Front Seat On A Rocket

Although I found it interesting to look at the exterior model, I spent most of my sim flight time in the SR-71 cockpit. The view from the front seat looks claustrophobic what with the massive dashboard and the tiny windows, yet this is where all of the action is.

In a real SR-71, there are normally two crew members: a pilot in front and a RSO (Reconnaissance Systems Officer) in back. The pilot is in control of the aircraft, while the RSO typically monitors the payload and defends against missile attacks. A Blackbird rated for training is included with the AlphaSim SR-71 package. The trainer has a second cockpit mounted above and behind the pilot's cockpit.

Virtual Cockpit (VC)



The rare training variant for the SR-71. The trainer sits in back, while the

trainee sits in front. Only the trainee's cockpit is available in the

simulation.

I primarily flew my sim-flights with the Virtual Cockpit (VC). The most impressive part of the cockpit is the detailed dashboard. The gauges are very close to what you would find in a real SR-71. For example, the stand-by attitude ball is directly over the main attitude ball. In most other aircraft, the stand-by controls are off to one side and out of the way. The stand-by ball is calibrated seven degrees higher than the main ball. This helps the pilot maintain level flight during high-altitude supersonic flight, where the SR-71 flies with a seven-degree nose-up attitude. Many other SR-71 models that I have seen pictures of miss this detail.

The default Virtual Cockpit view. The instruments are dark but readable. The view outside is limited by large

pylons. Even so, the Earth looks beautiful.

A wide view of the cockpit. The instruments look realistic and are placed accurately. Note the two

attitude balls. Also, there is a "Nav Map" display at the bottom of the

dashboard.

Other interesting and realistic gauges include a very precise angle-of-attack (AoA) indicator and the Triple Display Indicator (TDI). While many aircraft have an AoA indicator, few are calibrated as precisely as that of the SR-71. There's a red line at positive fourteen degrees. If the nose goes above that during supersonic flight, you probably will need to eject!

The Angle of Attack indicator, with a red line at fourteen degrees.

The Triple Display Indicator (TDI) to the left and the horizontal Situation

Indicator (HSI) to the right. Both are extremely useful in flight.

The TDI is a bit like pressing SHIFT-Z on the FSX keyboard. The TDI gives the pilot a digital reading of airspeed (KEAS: Knots Estimated Airspeed), pressure altitude, and Mach number.

Some of the gauges bend reality a little. The "Nav Map" data projector was an early attempt to create an inertial guidance system for the Blackbird. A crude computer could plot your position on a little plastic map that moved as you flew. The AlphaSim "Nav Map" is the default Garmin GPS screen with some new window dressing.

Another helpful system that is not very realistic is a novel tool for requesting mid-air refueling You can ask for fuel from any AI (Artificial Intelligence) aircraft in FSX, that is, any aircraft that is being flown by computer in the sim. Operating the fuel controls brings up a real-time listing of AI aircraft in your vicinity. Choose a likely aircraft. If you



are able to, you can include tankers like the Boeing KC-135 Stratotanker in your AI aircraft list. However, the AlphaSim SR-71 will accept fuel from any AI aircraft, including jetliners and General Aviation aircraft. Then, fly in close formation behind the "tanker" you have chosen. Once you are in place, your fuel tanks will quickly top up. Sim pilots can adjust the difficulty of this operation by adjusting how close and for how long the Blackbird needs to stay in formation. The default settings are very lenient.

I rendezvous my SR-71 with a tanker for mid-air refueling This tanker is

not included with the AlphaSim Blackbird package.

One gauge that is pure fiction is a neat little "radar" scope in the cockpit. This appears as a pop-up if you are looking to refuel in mid-air. The radar scope shows all of the AI aircraft that surround you, and highlights your chosen "tanker" in red. This helps you get closer to your "tanker" so that you can fly in formation with it. In the real SR-71, the pilot, the RSO, ground controllers, and the tanker crew would all be in voice contact during refueling. Since FSX cannot support that level of communication, the fake radar scope is a helpful tool to get your Blackbird to rendezvous with the tanker.

All of the main dials and switches are accurately placed on the dashboard in the AlphaSim SR-71. The modelers did an outstanding job of placing each device in its proper place. There is very little difference between the AlphaSim Blackbird and what I see in the real world operations manual.

The two things that I see as being different are the Inlet Restart Switches and the standard FSX pop-up controls. The Inlet Restart Switches are used in the probability of a loss of engine power. In FSX, these are used like the

CTRL-E command to autostart the engines. At first, I thought it was a bit silly to have autostart switches on the dashboard. However, flying past Mach 3 is not easy! It takes very little disturbance to create an unstable airflow that knocks out an engine, even in FSX. Sim pilots want a quick and easy way to get the engines re-started before the SR-71 plunges into an uncontrolled spin. I now respect the decision by AlphaSim to include autostart switches.

The FSX pop-up controls are the typical little buttons that activate new windows for close-up views of critical instruments. Even with a TrackIR to help me look around the cockpit, I welcome the pop-ups that help me see the radio, throttles, and other controls more clearly.

Crucial for smooth flight is the fuel gauge pop-up. This allows you to see the fuel gauges and activate the fuel pumps. If you remember the old Concorde from FS2000, the SR-71 is the same in that it is very sensitive to changes in the center of gravity (CoG) past Mach 1. As fuel is burned off, the weight of the aircraft changes. This must be balanced by manually adjusting the fuel pumps to keep the CoG within acceptable limits for your airspeed.

I've activated some pop-up windows, particularly the fuel pump controls,

the radio, and the autopilot.

The Nav Map display is clearly visible. The joystick yoke has no textures on it. A few other cockpit textures are

missing as well.

I like very much the layout of the dashboard. The SR-71 cockpit is like a space capsule, so apart from the instrumentation, there isn't much to see. Even so, things like the ejection seat and the joystick are missing textures. Other surrounding textures are bland, blotchy, or both.

The tiny windscreen draws criticism, as well, but not from me. It's important that windows be large in flight sim, because for most people their single computer monitor is the limit of what they can see. However, the windows on the real SR-71 are small, and there's a substantial metal pylon directly down the missile of the view. Real Habu pilots



will lay on the rudder during final approach to see around the pylon.

Night lighting is actually a bit spooky, but it is effective.

With a head-tracking device like TrackIR, it's fairly easy to find a good view out of the tiny windows. It's unrealistic because the TrackIR gives you more freedom of head movement than you would have inside of a pilot's pressure suit. Even worse is the "head bobbing" inertial movement that FSX automatically generates when simulating changes in G force. Since FSX gets a little strange at Mach 3, small changes in your flight can cause your virtual head to bob around more than you may be used to.

A close up of the throttles. Triethylborane (TEB) is injected as a catalyst into the turbojets every time

you start the engines or the afterburner. The real SR-71 contains

enough TEB for 16 injections. Although the AlphaSim cockpit

depicts the TEB shot counters, the number of injections in FSX is

unlimited.

Even worse are sudden decelerations. Several times, my virtual pilot's head would come free of where the neck should be and hit smack dab on the dashboard so that the stand-by attitude ball filled the screen. Then my virtual neck would

snap back like a rubber band and my view would turn to normal. It's a crazy ride!

Lastly, the VC is a frame-rate hog, at least on my test system. I was getting frame rates equal to or slightly below what I would expect from the default FSX 747. Of course, where you are headed with the SR-71 is the one place where frame rates are at their best: flying just beneath the roof of the sky. So on the ground the AlphaSim Blackbird is sluggish, but at altitude it’s a performer.

2D Cockpit

I didn't test out the 2D cockpit very closely, although it does show an improved frame rate over the VC. In addition, the window view is enlarged. AlphaSim compressed and moved around some of the gauges, so the layout of the 2D cockpit is not as realistic as the VC. I found the dials small, blurry, and hard to read. Aside from that, the artwork in the 2D cockpit is nicely done.

If you cycle the window views with the "W" key, you will see what AlphaSim calls a "mini panel". This is a stripped-down version of the main 2D cockpit to allow for maximum window view. All of the main controls are at your disposal with an enhanced windscreen that will allow you to see the runway on final approach.

The 2D cockpit comes in normal and widescreen variations.

The 2D cockpit at night. I have opened the default Garmin GPS and

the fake "radar" used for mid-air refueling

The AlphaSim "mini panel" cuts down on instruments, but gives you a

much wider view. It's best used on final approach.

For those that have widescreen monitors, AlphaSim supplies 2D cockpits in the 16:9 long aspect ratio. You don't see any more in the widescreen 2D cockpit than the regular one, but at least the dials are circular.

SOUND EFFECTS: Dies Irae ("Judgement Day")



In a real SR-71, the flight crew wear pressure suits. Wrapped up like a cocoon with the helmet seals intact, you cannot hear much of anything except the suit radio, ventilation, and your own breathing. Of course, if you are wearing a pressure suit in a SR-71 under full afterburner, you are also going to hear something else: two fully enraged J-58 turbojets!

Suitably, the sound file for the AlphaSim Blackbird seems very straightforward. Mostly, the only thing you hear is the engines. What glorious engine sounds! From start-up to spool down and every setting in between, the engines sound mighty and convincing. The closest comparison that comes to mind would be to sit at the feet of some fantastic pipe organ during Mozart's Requiem. Well, maybe that's over-praising the sound file. Still, there is a powerful, musical quality about the engine tone that adds "gravitas", a dramatic weight to the flight of the Blackbird.

The monumental roar of the engine thrust dominates the sound set. ATC voices become muted and hard to hear with the engines on afterburner. I did not hear any sounds for operating switches or levers, except for the sound of the landing gear lever and the cockpit canopy latch. When you put the wheels up or down, you can hear a muted click and whine as the retractor motors engage. The only other sound of note is the stall warning klaxon. Since there are no flaps or spoilers, there's no extra sounds from that equipment. Also missing is any audio indication that you've broken the sound barrier, although I don't think FSX can make a sonic boom.

FLIGHT PROFILE: On Top Of The World

There are things I like and dislike about the AlphaSim SR-71, up to this point. If I were to end the review here, I think I would categorize the AlphaSim Blackbird as a good effort, but I would like to see more. Fortunately, the best is yet to come!

I consider the airfile for the AlphaSim Blackbird as its most important feature. The flight profile is one of those rare works that is challenging, entertaining, and educational all at once. Down to earth, you will find challenge watching that your angle of attack and airspeed do not get out of control. Up in the stratosphere, you will discover that you have miles and miles of airspace to move around in, but that fine control is sluggish. After all, the air is much thinner at 80,000 feet. Momentum and engine thrust define which way the nose will point more than stick and rudder controls. The AlphaSim Blackbird will produce for any sim pilot flying challenges that few other products can provide.

The maximum safe aircraft speed at sea level for the SR-71 is 460 knots, which puts it in the same class as the P-51 Mustang. Too bad you will never see this sight at the Reno Air Races

Unlimited Class.

Forget those notions about tower fly-by's at Mach 3, or generating rooster-tails the size of skyscrapers by skimming the ocean waves. The top KIAS (Knots Indicated Air Speed) of the SR-71 at sea level is 460 knots, which is very close to the top speed of the WW-II era North American P-51 Mustang. And the Mustang is more manoeuvrable by a wide margin. Despite its prominence in the popular media as a space-age jet, the SR-71 requires adherence to a very narrow envelope of flight parameters, so it cannot be flown like a fighter.

The one thing the SR-71 does best is to fly in a straight line very fast and very high. Much of the work in flying the Blackbird is to get it up to operational altitude, and then bringing it back safely to Earth. The AlphaSim SR-71 can be flown by the numbers. It is best flown by sim-pilots who have had some experience with FSX, or those with a historical interest in the SR-71 program. Rookie or casual sim-pilots may find that the flight profile is difficult to follow. Certainly anybody expecting to "turn and burn" with the SR-71 will quickly discover how to stall, flame out, spin uncontrollably, or some combination of all three.

Taxi and Take-Off

I've read that the AlphaSim Blackbird could be difficult to taxi. I am happy to report that nose wheel steering is accurate, but it does not steer tightly. It's a lot like steering an airliner, except that the windscreens don't let you see much. I needed a lot of military thrust to get the SR-71 rolling, but then I had to cut back on the throttle to avoid picking up too much speed. Like a jetliner, taxi seems most controllable in the ten to twenty knot range. Go any faster than that, and nose wheel steering is affected.

Take-off occurs under afterburner. The afterburner itself can take a few seconds to ignite as the engines spool up and the triethylborane (TEB) works its way out the exhaust. The thrust is incredible. Even so, you need a lot of runway to get airborne. Rotation occurs at about 230 KIAS. If you are trying to keep below a speed limit of 250 KIAS, you have to be very watchful that you do not overspeed or stall. An overspeed warning light will let you know if you are going



too fast.

It is crucially important for the nose to rotate not more than fourteen degrees AoA in sub-sonic flight. Past that degree, the large delta wing has tendency to catch too much air, which causes the aircraft to perform a slow-motion flip. In a smaller, more agile aircraft, this would not pose a life-threatening problem. In a real Blackbird, the worst-case scenario would be that the fuselage would be ripped in half by torque. The best-case scenario is an uncontrollable spin with flamed-out engines. At least if you are at altitude, you have a chance to recover the plane and get the engines going again.

This Blackbird roars into the evening sky on a clandestine mission. Although the aircraft itself is

considered stealthy, its afterburner exhaust will light up on radar stations

hundreds of miles away.

Climb

Climbing past ten thousand feet, you can ignore the speed limit of 250 KIAS and open up the throttles. The afterburner takes a few seconds to kick in as the TEB shot runs through the system. Then you get some decent acceleration. You can just accelerate and climb to 80,000, but you will waste fuel and time. A more realistic approach is to perform a "step climb" like the big airliners do. Climb to 30,000 at 400-450 KEAS at minimum afterburner. Then level out and firewall your throttle. Accelerate past the sound barrier and then continue to climb. You can gain even more speed by engaging in a shallow dive above 30,000 to get past Mach 1 even faster. The AlphaSim manual refers to this as a "dipsy-doodle".

Climbs can be grueling. Consider that you can't ever pitch the nose up past 14 degrees AoA, so climbs in the Blackbird tend to be shallow and very long. The autopilot is partially helpful in a climb, but it doesn't have fast "reflexes". A highly aware pilot is required to anticipate and correct problems in the climb trajectory. A large portion of climb should be flown by hand, if possible.

The AlphaSim Blackbird seems to be highly susceptible to buffeting in the air. Unless you are flying in perfectly clear conditions, you can expect a bumpy ride. This adds to the challenge of flying the SR-71.

Cruise

The SR-71 cruises most comfortably at 80,000 feet at Mach 3.2. You can take it higher and faster, but it becomes difficult to control. At 80,000 feet, the aircraft controls feel sluggish. It helps to rely on the autopilot. You want to have plenty of time to line up your aircraft for a perfectly straight speed run. Turns at Mach 3.2 are very, very gentle. In fact, it's better to slow down if you want to turn the Blackbird.

At 80,000 feet, the curve of the Earth is apparent in FSX.

Getting past Mach 3.0 using the autopilot is a little tricky, however. A limitation in FSX autopilot function prevents it from displaying any Mach number greater than 3.0, although it is possible to fly faster than that. You have to bypass the Mach number by entering your speed as KEAS. After that, the autopilot will hold speeds greater than Mach 3.0. I think of it as the space-age equivalent of wiggling the toilet handle a bit to get it to flush properly.

Any sudden control movement during supersonic travel will probably result in an "unstart", where the afterburner flames out. This can happen a number of times on a flight, especially if you are new to the SR-71. The real SR-71 had some automatic restart equipment. The AlphaSim version simplifies this with basic restart switches. I really like those switches a lot.

Unstarts can sometimes be fairly gentle, in that your momentum keeps you from falling out of the sky. However, if only one engine unstarts, then you get issues with asymmetrical thrust, and the spinning begins. At 80,000 feet, you have a lot of time to try to recover spins. At that altitude, though, there isn't a lot of air for the control surfaces to catch, so spins can become very violent. There are terrible stories of the flight crew being thrown around inside of the cockpit as the result of such spins. The aircraft can only take so much torque before it breaks apart. In FSX, you can make your Blackbird indestructible, so all you need to worry about is recovering from a death spiral, no easy task.

Descent



Time to return to home base. Nose down slightly and reduce the throttles

to shut off the afterburner.

Returning to Earth is a careful process. The Blackbird can take only 0.2 negative G and 2.5 positive G, so advanced combat manoeuvres are out of the question. Retard the throttles and gently nose down to Earth. You want to aim for a spot roughly 100 miles from your home airbase. As you descend, pay close attention to your center of gravity (CoG). You will probably need to pump fuel to keep the CoG in the safety zone. Pumps can be set to automatic control, but eventually you should set the CoG manually. This is not difficult, but it does require some attention. Cockpit warning lights will alert you to fix your CoG.

Landing

This realistic-looking drogue chute operates like a spoiler to slow down the SR-71. In a real Blackbird, the

drogue is jettisoned, but the AlphaSim chute is infinitely re-usable.

The autopilot is capable of CAT III landings. The Blackbird handles something like a large airliner on approach. It's best to do a circuit in

the pattern around your home base to make sure you can maintain a good airspeed and have time to line up for landing. The windows don't let you see much, so you can apply rudder to swing your view back and forth. The big delta wing will create a large ground effect as you get close to earth. I think an Airbus-style flat approach works better for the SR-71 than trying a Boeing-type of flare.

The Blackbird needs a lot of runway to slow down. You can pop the realistic-looking drogue chute to help you decelerate on the runway. If all has gone well, you can tap the toe brakes, taxi off the runway and return your Blackbird to its roost.

MISSIONS: Eye In The Sky

The AlphaSim Blackbird for FSX does not come with any pre-rendered Missions, which is a bit of a shame. If there ever was a bird built for adventure, this one would be a front-line contender! The manual does provide a basic example of a Habu flight that originates from Kadena Airbase in Japan, skirts Soviet airspace close to Vladivostok, and then has you return in time for supper. The sim pilot can file his or her own flight plan based on this mission, or they can make up their own.

Multiple-choice exam. Choose the correct answer from the choices

below: A) "Ground Control to Major Tom..." -

think 1970's David Bowie. B) This is me auditioning for Heavy

Metal! The Stage Musical. C) It's the view of the RSO station,

with the surveillance camera inactive.

What is innovative and very, very cool is that you can use your SR-71 as a photographic platform within FSX! Yes, you too can fly realistic "spy" missions and take authentic aerial photographs of ground scenery. Of course, you won't start any international incidents by flying over "enemy" land. It does add to the challenge to fly next to a country's border without crossing it, using side-mounted cameras to look deep into their territory.

The entire photographic process takes place within the RSO (Reconnaissance Systems Officer) station behind the pilot's seat. This station is a clever extension of the virtual cockpit. Basic controls allow you to set up the SR-71 surveillance camera to take automatic or manual photographs. The camera is armed once the aircraft reaches at least 70,000 feet and Mach 2.6.

If you want automatic photographs, you need to file a GPS (Global Positioning System) flight plan using either the built-in FSX Flight Planner or some other utility. Put a GPS waypoint on the map where you want your SR-71 to shoot photos. I would suggest something the size of an airbase, or larger. My initial idea was to photograph my house, but from 80,000 feet it's just a pixel.

When the aircraft is within 5 miles of the GPS objective, provided you are

traveling fast and high enough and that you aren't banking or pitching, the automatic camera will start taking snapshots of the terrain below. You can over-ride the automatic shutter and take pictures manually by pressing the



An actual reconnaissance photograph taken with the AlphaSim SR-71. Fans of the movie "Dr. Strangelove" will

immediately recognize this as another aerial photo of Burpelson Air Force Base. In reality, the picture of Burpelson AFB in the movie was that

of Heathrow Airport, London, England.

RSO's trigger button. Screenshots are all saved automatically onto your hard drive.

Be aware that the automatic screenshots take pictures of what you are doing the moment the shutter is fired. If you aren't looking through the RSO camera sight, then the automatic screenshot will be of whatever it is in FSX you are doing. So, for example, you cannot be in the pilot's seat flying the plane while the RSO takes pictures, or you will have a series of pictures of the cockpit view the moment you fly over your objective. To get good aerial shots, you should have your Blackbird on level autopilot, and sit at the RSO station with your finger on the shutter trigger.

With a supersonic flight plan that can take you from sea level to the stratosphere, the ability to re-fuel in mid-air using AI aircraft, and the operational spy camera built into the AlphaSim SR-71, the Cold War was never this easy, this good-looking, or so much fun!

CONCLUSION: Executive Summary

The legendary Lockheed SR-71 Blackbird has been re-created by AlphaSim for FSX. This model stays true to the iconic look and sound of this exotic aircraft. However, the star of the show is the detailed and realistic flight model. The real Blackbird was capable of flying at over 80,000 feet and could cruise at Mach 3.2. This is not an aircraft for casual sim-pilots, but is well suited for those who are interested in finding new challenges in Flight Simulator and those who have a deep involvement with supersonic jets.

Getting the Blackbird to its operational altitude and speed is lot of work. Fortunately, the realistic cockpit has all of the instruments and autopilot devices you may need. Keeping the aircraft stable in the upper atmosphere is a real challenge. Engine unstarts, where the afterburner flames out, will occur any time you disrupt the airflow the ramjets need for Mach speed. As well, the pilot must constantly maintain proper pitch and attitude at all times, or else the aircraft will spin out of control. The Blackbird is not a fighter jet. It does not respond well to sudden control movements. The AlphaSim version can, however, be flown exactly to the specifications of the manual.

The SR-71 afterburner creates "shock diamonds". This is typical of the

engine exhaust during supersonic flight.

As a bonus, the FSX version of the AlphaSim SR-71 features in-flight refueling during Free Flight as well as the ability to use powerful "spy cameras" to take realistic aerial photographs during a mission.

The in-flight refueling system has you choose a "tanker" aircraft from the list of computer-driven AI aircraft that are in Flight Simulator. You can pick any aircraft to use as a "tanker". If you have your own tanker model, such as a Boeing KC-135 Stratotanker (not included with the SR-71), you can import it into FSX for use as your tanker. Or you can use any jetliner you like. Simply fly in line astern formation with your "tanker" and the SR-71 will take on fuel. You can adjust the process to make it easier or more difficult to suit your needs. A very useful fake "radar" system has been included to help you rendezvous with your tanker.

The AlphaSim SR-71 comes equipped with an array of cameras for taking pictures of ground installations. The Blackbird's primary mission was aerial espionage, so I found it thrilling to try out the cameras in FSX. The cameras

can look either straight down or off at an angle to either side. They can be triggered to operate automatically when arriving at a GPS waypoint, or they can be fired off manually if you are traveling fast enough and high enough.

I found that the AlphaSim SR-71 was not a good perfumer in terms of frame rates, at least close to the ground. I also have some issues with the artwork, especially minor bits of the textures I did not like. The FSX model also does away with a few small animations and effects that the FS9 model used.

However, I do like the challenging flight model a lot. It's a real accomplishment to set up a flight plan and roar into the sky. Mid-air refueling can be tricky, and requires a sure hand on the throttle. Then, climbing up into the stratosphere and performing your speed run is spectacular. Precise piloting is required for your spy pictures to turn out well, especially if you are trying not to encroach over an "enemy" national border. Finally, returning to your home base and landing will test the mettle of any steely-eyed sim-pilot.



THE LAST WORD: Triple Treat

Test System

Intel Core 2 CPU 6600 @2.40GHz x2 2 GB RAM NVIDIA geForce 8800GT Superclocked Edition RealTek AC'97 Audio Win XP SP2, FSX + Acceleration Thrustmaster Top Gun Afterburner II Logitech MX Revolution Laser Mouse MS Digital Media Pro Keyboard Saetek Pro Flight Rudder Pedals TrackIR4:PRO TrackClip PRO XBOX 360 Controller DBS Walk And Follow

Flying Time: 22 hours

The new Blackbird shows the high level of quality of which the AlphaSim team is capable. It looks to me like quite a bit of the technology that went into the SR-71 model is shared with other AlphaSim products, especially the afterburner affects and the delta-wing flight model.

David Bushell, the project leader for the AlphaSim SR-71, was very gracious in allowing me to interview him by e-mail. Here are some of the things he has to say about the realism of this aircraft for FSX:

Jeff: David, please tell me about what got you started with creating a model of the Blackbird.

David: I originally started out in flight simulator 2000 - at first by searching the popular sites trying to find an SR-71. I found one eventually, but felt I could add something to it and at that point, I picked up Aircraft Factory '99 and started to build aircraft. At the time I was restricted by the polygon count and only achieved a few aircraft, most were never uploaded anywhere.

My love for the SR-71 took a new twist in 2004 when I met Bob Gilliland - the test pilot of the SR-71s first flight, and James Eastham, first flight pilot of the YF-12 at the Blackbird Airpark California - the 40th Anniversary of the SR-71's first flight in 1964.

The AlphaSim SR-71 for FS2004 started out during the first quarter of 2006, and was released in February 2007 along with Beale AFB for FS2004 and FSX. Originally, the FSX version was a port over, and worked fine until FSX SP2. Once SP2's affect had been assessed I decided to compile the model solely for FSX using the FSX SDK and all the FSX bells and whistles like self shadowing of the exterior and VC along with bump mapping the wing corrugations for a little piece of extra realism and FSX SDK specular shine and back lit gauges.

Rich Graham (Col, USAF retired), SR-71 instructor pilot, SR-71 squadron pilot of 7 years, 1st Strategic Reconnaissance Squadron, Director of Program Integration at the Pentagon and 9th Strategic Reconnaissance Wing Commander said this of what he saw on our forums: " I was extremely impressed by the level of detail in your display of 955. Everything looks true to form. You obviously take great pride in getting things right and you've succeeded on the SR-71."

I cannot tell you what that meant to me!!

Jeff: What makes your SR-71 different from all of the others?

David: Aside from the realistic cockpit, which has 59 working gauges and switches, and the new and improved paint schemes, the flight model is perhaps the aircrafts greatest feature.

We didn't want another yank and bank SR-71 that can do extreme fast high G manoeuvres - the real world SR-71 was more fragile than people realise!

It has unquestionably the best SR-71 flight model out there - this SR-71 must be flown by the book. As an example, your climb profile must be close or match the real life climb profile in order to reach heights above 75,000 feet and Mach 3+. Due to the time taken and fuel wasted breaking through Mach 1 in horizontal flight the real world SR-71 pilot would perform what they called a "dipsy doodle" manoeuvre whereby the pilot climbs to the low 30's and approximately Mach 0.95, then descends 3 or 4 thousand feet, then gentle pulls the stick up once Mach 1.15 is surpassed. Once climbing the pilot must control the throttle as close as possible to roughly 450 KEAS. He must maintain 450 KEAS all the way to Mach 2.6. Beginning at Mach 2.6 the pilot would then decrease KEAS 10 knots for every 0.1 Mach until the desired cruise speed was achieved. As with real life SR-71's the high altitude performance dictated that it must be flown within set parameters - this includes angle of attack. If you pull to much Alpha while climbing at too low an airspeed, or indeed while turning at significantly slower than cruise speed at high altitude your engines will flameout from being starved of sufficient airflow, requiring a restart. All this is avoided by flying the profile by the book. If you are unfortunate enough to have



both engines flameout, leading to oscillations greater than the conditions required to restart the engines you can end up not being able to restart the engines on your 15 mile trip to the ground. I had at least one test flight end up in the South China Sea after trying to manually tighten the radius of a long turn!

This exact flight profile is possible using our SR-71. Jay, our flight model guy worked day and night perfecting the flight model using data and performance charts from the SR-71 pilots manual. The flight model even includes the better fuel economy provided by the engines at speeds of Mach 3.

Not only does the flight model very closely match real life performance we also built in some fuel management and the Centre of Gravity can be critical if not monitored during the flight - handling problems will begin if the fuel is too far forward or aft which in turn could lead to flameouts as mentioned earlier and degradation of performance. Aside from the SR-71A model, the SR-71B trainer variant has it's own unique flight model taking into account the affect of the ventral fins under the engine nacelles.

The FSX version has a first for FSX an aerial refueling facility (IN FREEFLIGHT) - you can now refuel from any AI aircraft using a built in pop-up panel with a handy (but not realistic) radar to locate your tanker. Once in close formation behind your chosen tanker the aircraft will take on fuel at various user definable rates and if your fuel is low enough can take anything up to a minute to top off the tanks. Of course any plane that takes on fuel needs to be able to dump fuel - we have a 3 minute emergency fuel dump and associated effects.

Aside from the above, there's a crew ladder, start carts under the engines, engine covers and a truly awesome set of sounds. Also there is an RSO station where you can use the SR-71 to photograph (take a screenshot) of your next waypoint provided you are within a set parameter (mentioned in the manual). Once armed the aircraft will take screenshots of the waypoint as viewed through the camera window and place them on your hard drive!

Jeff: What were the hurdles you had to surmount in creating the SR-71?

David: There were many hurdles during it's development - while Jay was getting his head down studying the performance charts, I spent many evenings and weekends trying to understand many of the complex systems on the SR-71 in an attempt to incorporate as many features as possible. In order to model things, it's best to understand how they work, and appreciate how they should be flown.

General public perception of these aircraft is that they're highly manoeuvrable rocket ships, we didn't want to build something that cheated physics, we wanted from the outset an aircraft that would represent the real world performance to a high degree. An aircraft that would inspire curiosity from the young and not so young alike. In order to answer some of their questions and to provide a guide on how you're supposed to fly the aircraft we produced a 50 page 'Operations Manual' which contains a brief history of the aircraft with photographs, full performance data, climb and descent schedules, CG positions and a full description of the various knobs and switches in the 2D panel and VC.

One customer described the aircraft as the first he'd flown in flight simulator that required him to read the manual after 5 minutes of flight! The G limit is 2.5 positive G, and only -0.2 negative G. This means that it has more or less the same limits as the C-5 Galaxy! It also has a maximum indicated airspeed of only 460 knots - the same as a P-51 Mustang!

The SR-71 in real life leaked fuel since the fuel tanks only sealed once the temperature of the skin increased during the Mach 3 cruise, and the aircraft often met a tanker after take-off not because the fuel leaks so much, it's because take-off is much safer and causes less wear to the main gear tyres. Heavy weight take-offs were performed sometimes at Palmdale since the availability of tankers in the area was a factor. I could go on for hours; it was a real labour of love for all of us involved with the project. Once it was finished, it left a big hole that I now fill with flying it instead of testing it!!

Jeff: Thank, you David, for providing us a look into your work with the AlphaSim team!

Now, I would like to end my review with the promise of a "triple treat"! Originally, my intention was to put this review alongside two other SR-71 related products: the Beale Air Force Base scenery by AlphaSim (the last official "home base" of the Blackbird on continental American soil), and the Lockheed SR-71 Pilot's Flight Operating Instructions, which is the de-classified flight manual for the Blackbird recently published by periscopefilm.com.

Instead, I will feature these two items in their own upcoming AVSIM product reviews. Anyone interested in the SR-71 program should watch out in the near future for these upcoming articles: Beale AFB by AlphaSim and the Pilot's Manual for the SR-71 by Periscopefilms.com.



What I Like About The SR-71

● Challenging, by-the-numbers supersonic flight profile!● Thunderous sound set● Ability to refuel in mid-air in Free Flight● Ability to take reconnaissance photos● Accurate-looking Virtual Cockpit● Excellent and informative manual

What I Don't Like About The SR-71

● Problems I had with textures● Frame rates can be low● 2D cockpit gauges small and blurry

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