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L45-1001 Build History

Lear 45-1001 Build History

Revised 22 December 2022

I’m DonnyRay, and this is the build history thread for my current airframe, L45-1001. This is the third Lear 45 sim I’ve built.   I selected airframe serial number -1001 for it to avoid any confusion with a real aircraft.

L45-1001 is not a typical hobby effort. It is built to actual scale, same as the real aircraft, uses as many real Honeywell Primus 1000 avionics as are practical, and implements many features not supported by FSX or P3D. It replicates the aileron and elevator disconnect systems with high fidelity. It has a 3-axis servo controlled autoflight system. It has a functional entry door. The airframe is designed to accept a motion base in the final phase of the project. It has as many other features of the real aircraft as I can fabricate and include in the airframe.

I mentioned that L45-1001 is my third Lear 45. I made many mistakes on the first one. The second one could not accommodate several features of the aircraft. L45-1001 is a clean sheet design and represents my effort to faithfully replicate the real aircraft. A great deal of the design information used on L45-1001 is from Bombardier Learjet factory publications. Many of my earlier mistakes were due to lack of adequate information. I’m working very hard to make this airframe faithful to the real aircraft by referring to factory documentation whenever possible.

L45-1001 does not use the Rollo shell system. It is intended to be an avionics integration test bed and will be equipped with a motion base. Thus it must be somewhat larger than the Rollo shell to accommodate the avionics bay in the nose and to provide a controlled center-of-gravity (CG) for the motion base. Features and techniques developed on L45-1001 are available to any Lear 45 builder and many of them will work with the Rollo shell system.

Someone may ask, “What’s the difference between a “regular” sim and an “avionics integration test bed”? In a word, flexibility. A test bed is constructed in a way that allows easy access to the device(s) or system(s) under test. This permits quick and easy changes, revisions, or other modifications that may be required as future features are implemented. For example, it’s possible to test a variety of I/O cards on L45-1001 by removing a remote box and installing another one which contains a different card. Because the system is modular in nature it’s also possible to fly it with different simulation engines (FSX, P3D, X-Plane, etc). It’s very easy to test software features in application suites such as Jet45. “Production” versions of items developed on L45-1001 can be replicated for regular sim construction once a preferred solution is identified and tested.

“Why go to that effort?” Since I constructed my first Lear 45 sim in 2003(?), many, many, hardware and software products have come to market, achieved popularity, and then disappeared. I’ve been “stuck” with some of those products. The cost and aggravation of replacing them prompted me to build this airframe in a way that makes it software and hardware agnostic. A primary objective is to allow for easy changes to hardware or software. Single source products always put the buyer at a disadvantage, but it’s possible to reduce the risk of using them if a project *plans* for replacing items that become obsolete or orphaned. The L45-1001 build design makes this possible.

This is a good time to review terminology. In these postings I’ll try to use the correct FAA, ATA, and aerospace industry words and references unless the result is unclear. When I use the word “aircraft” it always refers to a real, certificated, and flyable vehicle. Hangar45 builders will know that refers to the Learjet model 40/45 series. The word “sim” (short for simulator) refers to a replica of an aircraft. Regardless of the physical completeness of the airframe, a sim is never intended to leave the ground.

L45-1001 is presently under construction. Even though I work on it nearly every day it is substantially incomplete as of November 2018. Progress has mostly been a function of the effort required to faithfully replicate the aircraft. For example, the pedestals, MIP, and glareshield are all fabricated from aircraft alloy aluminum (2024T3 Alclad). The forward elevator disconnect clutch and related assemblies closely replicate the aircraft.

Building these parts using aircraft materials and techniques is necessary to faithfully replicate some of the functions of the aircraft. (Some things just can’t be done with wood.) Fabrication using aircraft alloy metal isn’t difficult and doesn’t require a lot of special tooling but it takes significant time. And patience! Sometimes I make a part and it works, but it’s hard to fabricate or requires hard-to-find components. That’s not a good solution for other builders so when that happens I’ll pull that part and start over with a different design. The process is slower, but I get a better result.

My Hangar45 postings related to the L45-1001 build history are loosely organized in accordance with the Airline Transport Association (ATA) standard numbering system. The ATA system provides standardization in the arrangement of all aircraft publications by use of a simple, uniform, numbering system. The numbering system is a three element dash number that provides a means for dividing material into Chapter, Section, Subject, and Pageblock. It also identifies the hardware that is the subject of the text.

For example, ATA Chapter 24 covers Electrical Power, ATA Chapter 27 is for Flight Controls, and so on. The numbering scheme applies to all related publications including maintenance manuals, parts guides, wiring manuals, etc. So if you know that the information you’re looking for is in chapter 53, “Fuselage” you’ll know it’s always under that chapter regardless of the type of manual in which it appears. The ATA standard specifies 116 Chapters and includes subjects specific to flight simulators. For further information on this standard refer to ATA iSpec 2200 “ATA Standard Numbering System”.

I recommend that readers of this build history check this post for the most current information. Use this post sort of like a table of contents. As I post material it will be listed here along with a link to the posting. Instead of searching around on Hangar45 for an item of interest, look here first for information specific to L45-1001. I’ll update this post as I add more material. Look at the END of this post for material that has been posted including revisions and updates to existing posts.

I’ll try to post material on a regular basis. Taking photos and writing posts takes time away from fabrication but I’ll work out some schedule that minimizes impact on my own build progress. I’ll include some lessons I learned (“Don’t make THIS mistake, or THAT error, but here’s a better solution”.) Most of my posts will be documentation of the build but I’ll explain in text details that I believe will assist others who may wish to duplicate some of these features. If you have questions I encourage you to ask them. We’ll all learn something.





L45-1001 Build History Introduction (this post), rev 16 Dec 2022

L45-1001 ATA Standard Numbering System, rev 14 Nov 2018:  HERE

L45-1001 ATA-53, “Fuselage”, rev 19 Nov 2018.  Airframe construction.  HERE

L45-1001 Structural Integrity Testing, rev 23 Nov 2018.  Is your airframe durable?  HERE

L45-1001 ATA-31, “Indicating/Recording Systems”, section -10, “Instrument & Control Panels”, rev 27 Nov 2018.  Forward and center pedestals.  HERE

L45-1001 Aircraft Aluminum Fabrication Tips rev 28 Nov 2018.  HERE

L45-1001 ATA-31, “Indicating/Recording Systems”, section -10, “Instrument & Control Panels”, rev 5 Dec 2019.  HERE

L45-1001 ATA 27-10, Ailerons, rev 15 Dec 2019.  HERE

L45-1001 ATA 27-30, Elevators, rev 17 Dec 2019.  Yes, there are two.  HERE

L45-1001 ATA 27-20 Rudder Control System rev 22 Dec 2022.  HERE


L45-1001 Flight Control System rigging.

L45-1001 ATA 27-50 Flap control

L45-1001 ATA 27-60 Spoiler control

L45-1001 ATA 22-10 Autopilot

And more as I can find time to write them…….

Thanks DonnyRay for sharing your incredible work!

I have had the pleasure of meeting DonnyRay on three occasions over the years and have seen L45-1001 up close and personal as recently as just a week ago!  DonnyRay is taking the Lear45 sim to a whole new level of functionality and it has me thinking of how I can implement some of the things he has mastered in my own sim.  Like DonnyRay, I am currently working on my second version of my Lear45 and after seeing L45-1001, I am already making plans to build a third version several years into the future.  If you have been in this hobby for any length of time, you will soon realize that the project is never finished.  There is always something to improve on or add.

As I said before, I have seen this Master Piece in person and without spoiling what's to come, all I will say is every Lear45 hobby enthusiast will be awestruck with what you see and read in future post by DonnyRay!

WARNING: Beware of brain firestorms from all the sparks of new ideas you guys are getting ready to see!

December 22, 2022

Hello Learjet 45 builders:

Please allow me to apologize for being away from Hangar45 and non-responsive to your queries.  2019-2022 has not been kind to my family.  We lost both of my aunts, my Mom, Ms. Debbi lost her Mom, and then in 2022 Debbi and I lost the battle with metastatic breast cancer.  We were married for 51 years.  She was the best thing that ever happened to me.

L45-1001 is helping me work through the grief and try to recover from the loss of Debbi.  There is no recovery, of course, but I am trying to do the best I can and keep moving forward.  It's HARD.

Ms. Debbi was fascinated by all the moving parts in the rudder pedal system in L45-1001.  I think this was due in part to the fact that she could SEE "how the clock works" rather than having to visualize some abstract thing like software.  Or "electricity".   I promised her I would complete the rudder control system and get it posted.  I have done that this week.

Thank you for your patience.  I will work on more postings as quickly as I am able to complete things which I hope you find helpful in your builds.  Your comments are always welcome.


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