Chapter 9 - Part 2: Main landing gear overview

Part 2 - The main landing gear:



The main landing gear strut is purchased prefabricated; however, a LOT of work is still required prior to installation. The main strut is fabricated out of 'S' glass in a mold. After purchasing the main strut, it is then sanded dull and laid up with 8 plies of UND for torsional stiffness. The gear is then trimmed in order to install the axles, wheels and brakes. Everything is then jigged and glass tabs are made in order to install the main landing gear assembly onto the fuselage.

There are many different types of wheels (tube or tubeless, aluminum or magnesium) and different types of brakes (internal or external calipers, sizes, braking energy, etc.) to choose from. Do your homework and see what best suits your needs. There are plenty of pros and cons with every combination.

5 comments:

Steve Howlett said...

Great Build!
I have really enjoyed reading the entire blog a few times now.
I am curious, with all of the work that was necessary for the main gear, why did you not install a retractable system?

Ary Glantz said...

Thanks Steve for the positive comments!

To answer your question, installing a retractable system is probably more time consuming and more labor intensive than the per plans fixed-gear option. In my opinion, a retractable system is not worth the added complexity. I haven’t performed the calculations, but I’m pretty certain the benefit of a retract system is not as significant as one would think on an airplane that typically cruises at less than 180 knots. Sure one might save some drag – but you also have to consider the added weight of a retract system – and that added weight requires more lift from the wing which brings the drag back up to where you probably were. If the airplane were to cruise at higher speeds, then it becomes relevant – since drag is proportional to the square of velocity.

In addition, I don’t think it’s worth the risk of a gear-up landing. Many Long-EZ pilots have forgotten to extend the nose gear on landing – although that sounds terrible, it’s not as big of a deal as if you had your main landing gear up. That would require re-glassing the entire bottom surface, a new speed brake flap, probably a new prop and a complete engine overhaul – oh, and a new cowl.

Aviator said...

What is the main gear strut made of? Can the strut be made by the builder?

Davecove said...

Ary, how much does the main landing gear strut weigh and where did you get yours?

Dave

Ary Glantz said...

Hi Dave,

I purchased my main landing gear core from Feather Lite. They do not have a website - but have been in business for 30+ years. Talk to Larry @ 707-462-2939. I never weighed mine. It's sitting in storage for the time being so as not to clutter up valuable workspace in the garage. Next time I have access to it, I can weigh it - but it will include the axles, wheels and brakes. I'm sure Larry would be able to tell you how much the core itself weighs.