My History With Flight Simulators

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I'm absolutely impressed with the level of detail provided with the Prepar3D / 737 NGX.  In my opinion seeing something that simulates the  interaction of the electrical, hydraulic, computer, and control inputs- is something I feel we don't see enough of.   And yes, I've been flying the Level-D 767 since it first came out as Pilot in Command, which in my opinion deserves an award for the being the first product to push the genre in this direction.

This diatribe will begin with my experience on a real-life simulator, and then end with some comparisons to the PMDG 737 NSX at the end.  If you get bored, my sincere apologies just quit reading and move on.

My first simulator was Bruce Artwick's subLogic Flight Simulator II on the Commodore 64, so hey, I've been around the block.  I think I've owned every major flight simulator between 1983 and now and have built countless rigs to support them.  I don't know how many hours I have in simulators, and frankly I don't know if the true value would horrify me or not. 

Although I read a lot of forums, I'm mostly a lurker but since this is one of my first times to create a thread from scratch I'll try to make it count.

After college (Bachelor of Science in Computer Science) my first job was as an instructor at a technical college teaching COBOL/FORTRAN/RPGII/C programming to kids working on their Associates Degree.

Since dad had retired from the Air Force at Barksdale AFB, I was quite familiar with base - it was within walking distance of our house.

As for the KC-10 Singer-Link system, I knew of the existence of this simulator at Barksdale Air Force Base because of a friend I had met in an advanced college calculus class.  After we got to know one another one day I asked him, "So what's your major?".  And he replied that he didn't have one, and wasn't pursuing a degree.  This intrigued me, that someone would take such a difficult course out of the blue...

He explained he was a contract programmer on the Singer-Link simulator at Barksdale AFB and needed to better understand the wake turbulence experienced by a KC-10 as it was being refueled by a KC-135.  He explained the bow wave effects and how he was getting a handle on the math as he had to code this in Assembly Language and the systems they were using were already at 90% capacity from a CPU perspective.  I was impressed.

So a couple of years later it occurred to me that I might be able to leverage my position as an instructor to get a tour of their KC-10 Full Motion Singer-Link Simulator on the base.   A couple of calls later and it was all worked out - the base was delighted to have us- my employer (the Dean of the school) was blown away that I arranged this - a real win/win and my entire class was going to get a tour.

We got to operate the boom and refuel a B-52 below us; we got to play around in the procedures trainer, and of course we got a look at the data center used to run it all.

It was amazing - it took a basement of computers each the size of refrigerators to run this simulation- each major computer only worked on one small part of the sim- and fed the results into the next computer for further processing.  It was millions of dollars in equipment that could probably be handled now by a couple of decked out modern PCs with decent video cards.

While in the basement the pilot showed us printouts of the real pilots upstairs performing engine-out approaches.  He pointed to one green-bar printout and said, "This reflects an engine out approach where the back wheels weren't quite on the pavement upon touchdown.  It's a bit difficult because in a long plane like KC-10 the cockpit is well ahead of the rear wheels".

Well, no problem.  Or so I thought.

Later, when my class was standing near the scaffolding waiting, the Air Force pilots exited the simulator just as one of my smarty-pants students exclaimed, "Set it down in the dirt, huh?"   The look those two pilots shot back could have stopped the hearts of most small animals.  It was lethal!

When it was time to actually take a ride, only a couple of people could go since the cockpit could only hold a couple of folks at a time - everyone has to be strapped into seats since a sudden bump of the controls could send someone crashing into some very expensive equipment and toggle switches.

The Lt. Col. leading the tour had been eye-balling the girls in my class and when he asked who wanted to fly in the pilot's seat, everyone bashfully averted their eyes downward.  He kept looking at the girls to see if one would change their mind, but me- my arm was straight up into the air and after an awkward moment I could tell he was a little bummed that none of the girls volunteered!  With what was a heavy heart for him he said to me, "OK, come on." 

Using my entire class was a sneaky way to get into that simulator and fly it....and I pulled this entire trick twice during my time teaching there, exactly one year.  Both times I got to sit in the pilot's seat and fly the thing through some very specific maneuvers (fortunately the tour wasn't led by the same officer both times).

For those that have never experienced this, I'll explain a few things that made this experience incredible.

For one, they even had the runway cracks programmed in- you felt the bumps as you crossed them.  They had Barksdale and the entire cities around it represented.  It wasn't the same level of detail we're accustomed to, but the frame rate was rock solid and smooth.

When you take off, you're pressed back into the seat as the place accelerates.  When viewed from outside the simulator you can see that what is actually happening is that the entire enclosed cockpit is tilting backward.  Inside, you don't notice this because the computer is drawing the out of the window view that is compatible with rolling flat down the runway.  In addition as the plane picks up speed you've got the usual vibration occurring - incredibly realistic.   Bumps, cracks, sounds, visual, and of course all of the real cockpit controls, switches and instruments (all analog at the time!) was incredible.

Likewise, when coming to a stop, you feel the straps of the belts pulling at you- it actually feels like a strong deceleration but in this case the entire simulator is on hydraulic struts which are now tilting the entire cockpit downward.

Visually they normally set the simulator to dusk conditions - which they deemed the most realistic looking.  They even had the car headlights on some roads that were around Barksdale.   It wasn't as detailed as what we have in today's PC simulators, but it actually looked very good.  We (I) did a refueling over the grand canyon, purposefully broke the nose wheel off during a hard landing, and an on-purpose mid-air with the KC-135 we had been refueling from.

When we were taking on fuel from the KC-135 just above us, I was very surprised at how hard the Lt. Col. was struggling to hold our position, both mentally and physically.  I had assumed the flight controls were like power steering in a car.   When he said, "You've got the controls son" I could not believe the amount of effort required to hold our position - the updates required were constant with control wheel movements around 4-6 inches once to twice a second.  It was hard work - these guys must develop strong arms.

Watching you-tube videos of B-52s refueling they don't seem to struggle as hard to hold their position as we did- but dad says they had 2 modes in the B-52 for the controls and one was for refueling.  

I couldn't stay connected (the green "connect" light on the overhead goes out) and we eventually floated down and away to the right, when I heard the dreaded, "I've go the controls son."  That is when he pulled us up, hard and to the left, purposefully colliding with the underside of the KC-135.  

All at once it seemed there were lights on every switch in the cockpit and of course there were alarms and bells too- we nosed over hard, going into a dive.   About 4 seconds later everything stopped and the interior lights came on- he said at that point the computer had considered us dead and had stopped the simulation.

Another interesting fact - I asked him if anyone had attempted inverted flight or crazy maneuvers in the sim - and he said that going into a dive to pick up speed and then pulling up into a climb and then trying to go upside down to loop, was very bad because the computer at the top of the climb would have the hydraulics holding the simulator at full tilt back, but the moment you passed the 90 degree mark the computer would instantly command the hydraulics to put the simulator into a fully deflected downward position and the abruptness of the change was quite severe and not good for any of the equipment.  Same with trying a roll - these were forbidden because of the stress it put on the components when the computer tried to "snap" the cockpit (which must have weighed thousands of pounds) into an all new attitude.

After teaching I sent off a resume hoping to get on to the Rockwell International Simulation Team for the brand new B1-B at Dyess AFB in Texas but they never responded and I ended up in the Financial Side of Software Engineering.  I wanted in that B1-B simulator cockpit bad!

Since then, Barksdale AFB in Bossier City Louisiana is still home of the 8th Air Force 2nd Bomb Wing with approximately 44 B52s, but sadly the KC-10s have all been reassigned and it is doubtful that the simulator complex I visited exists there anymore.

Ever since that experience, I've been craving something that had the level of depth, and I've found it in the PMDG 737 NGX.  This plane has kept me quite busy, reading the manuals and learning the nuisances of its operation.  When I saw how big the manuals were (dashing my hopes of using the office printer to print them out unless I stayed late so as to not interfere with legit prints!) I didn't know whether to be elated or overwhelmed.   Turns out I'm still both.  And, I'm still determined to stay late one day this month and print this stuff out (in color!) and put it into sets of 3 ring binders.

Being a Software Engineer since 1988, I view the MSFS/Prepar3D/PMDG737 as a state of the art piece of software engineering - when I read some of the posts related to nit picking it makes me hope that the authors of this product don't take it personally.  The complexity of this product and the fact that it runs at anything other than slide-show speeds is truly amazing.  (I tried programming just a simple graphics attitude indicator on an Amiga 2000 using Manx Aztec C, and it ran darn slow!)

We finally have a working model of a wonderfully complex machine that we can experiment with on our very own PCs, a realistic simulation that rivals and in many ways surpasses the multimillion dollar Singer-Link system I had the rare privilege to fly in 1989.

I'm impressed with how far we've come.  As someone whose first simulator had 4 colors and a FPS of 2 and ran in 64K of RAM, it's a good time to be alive.

Thanks for reading,

Mark Trainer


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Mark, I throughly enjoyed reading your article! I am a bit puzzled though why you chose to use this editorial feedback forum to post it in. It seems to me that it would be more appropriate in the Hangar Chat forum so I'm going to move it where it may be seen by a much wider audience.

Thanks for sharing your very interesting anecdotes!

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Hello Mark

That was extremely interesting and informative.

Your valuable knowledge and experience shows in every line you wrote and the way you evaluate where we at on the simulation evolutionary scale.


I agree. We are well served by advanced electronics and computation power beyond our wisdom to appreciate appropriately. This is a golden age.

Your evaluation and historical perspective is appreciated.


Thank you for taking the time to put all this into print and trusting us with it.

Kindest regards,

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I loved reading this. Seeing as my history is way shorter in sims. However, I also only fly and live for 24 years, it is a great read! 




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An excellent read, Mark. I too have experienced home flight sims from the early days - one of my college teachers showed us the flight sim on his Apple II. I had a ZX Spectrum 48k back in the day. When I finally got a PC, I was blown away by subLogic's Flight Assignment ATP - navigating an airliner down the airways shown on the paper maps included, using VOR radials and DME.

I then progressed to a heck of a lot of virtual aviating with FS98 - numerous add-ons are collecting dust on a shelf now.

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We both started with Flightsim for the C64.  I was able to get the default Piper to cruise at over 200kts by putting negative values for the flap settings, covered quite a bit of ground that way!  I then graduated to FS for the Atari ST, which improved fps quite a bit.  Also was a Flight Assignment ATP fan, I hacked it to change the colors of the cities by opening it up in debug and looking for values for the texture colors, which I guessed based on the hex code the sim would probably use for the colors.  I also had Flight Unlimited 2 installed, my first sim that had photoreal scenery of the SF Bay Area.  A lot of sims since then, culminating with P3dv4 and XP11 today.


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I remember Flight Unlimited 2 - had that also!  I still have it packed away in a big box full of obsolete software.

Having purchased nearly every sim on the market from 1983 until current, I probably spent the most time in FS9 - AKA Flight Simulator 2004 - I flew it even after FSX came out, because of the inconsistent frame rate of FSX - it would run smooth but then stutter with a long frame about once a second.  That alone was an immersion killer.  Then, as PCs became ever faster, FS9 began to run like a dream - nothing like taking the Level D 767 in for a landing with a solid 60 frames per second.  Thus, I stuck w/ FS9 and frankly never really spent much time in FSX- went from FS9 right into LM Prepar3D V3. 

At first, I was a little disappointed with Prepar3d, at a glance the major upgrades I was expecting just weren't there.   Once I accepted that this sim needed add-ons such as PMDG aircraft, ORBX Scenery, REX4 w/ Soft Clouds, a decent camera system, and Active Sky, it all began to shine.  I had expected though that these would be incorporated into the sim by Lockheed but they seem content to continue providing a base-sim only and let 3rd parties do the rest.  It has its pros and cons but since my posts tend to go long I won't go into them here.

Glad you folks enjoyed the original article, I wrote it about 6 months ago and just didn't know if it was something worth posting but now I am glad that I did.


Mark Trainer



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