• Welcome aboard HomebuiltAirplanes.com, your destination for connecting with a thriving community of more than 10,000 active members, all passionate about home-built aviation. Dive into our comprehensive repository of knowledge, exchange technical insights, arrange get-togethers, and trade aircrafts/parts with like-minded enthusiasts. Unearth a wide-ranging collection of general and kit plane aviation subjects, enriched with engaging imagery, in-depth technical manuals, and rare archives.

    For a nominal fee of $99.99/year or $12.99/month, you can immerse yourself in this dynamic community and unparalleled treasure-trove of aviation knowledge.

    Embark on your journey now!

    Click Here to Become a Premium Member and Experience Homebuilt Airplanes to the Fullest!

Taking a Spam Can and Making it Crashworthy

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

JayKoit

Well-Known Member
Joined
Jan 17, 2013
Messages
116
Location
Los Angeles, CA
I've finally finished reading the "Crashworthiness" and "Design for Crashworthiness" threads and have to say that was the most informative collection of posts I've read in a long time. Gave me a lot to think about regarding how safe to an airplane can theoretically be, how safe it possibly can be, and how unsafe many of the kits out there really are.

Before I get to the topic, I wanted to thank SVSU Steve, GESchwartz, Topaz, Dana, Vigilant1, wsimpso1, Orion, Autoreply, JimCovington, Aircar -- and everyone else who contributed to the crashworthy threads on this site. You've undoubtedly helped me to consider things I never thought about that will make my plane (once it's built) a safer airplane than it otherwise would have been.

I have been considering an all aluminum semi-monocoque plane for my first build for quite a while now (the Savannah VG, a Zenith 701 variant). I want to build this plane because it's a simple build -- every part is pre-drilled (with full size holes) and pre cut & formed, real world build times of 250-300 hours, multiple FWF kits with cheap engine options, and I can build the plane complete w/basic VFR for just over 30K.

However, after having read all that I've read, i realize that the plane's material & structure are not the most crash friendly. So, my costs will not stop there, because now I want to implement some additional safety features/mods to make my plane more crashworthy. I'd love to get some feedback from you guys about my ideas, and whether or not you think it will make my plane a safer plane. Understand that chewing up some useful load is not a concern for me, as this will be primarily a solo flying time-building plane for me. FYI the basic plane has a 600 lb useful load, and I'm a 165 lb pilot, so I have some room to work with.

Here's the list of mods/additions (and their links):

- Center "Y" stick so there's no impalation risk
- Second Chantz air propelled (not rocket) airframe parachute - Second Chantz Home
- four point airbag harnesses - LA MOUETTE - Ailes delta et ULM - Vol libre - Vol moteur
- Rubberized crash resistant fuel tanks - Manufatti Elastomerici Rinforzati - Merin S.r.l.
- 3-6" confor foam energy absorbing seat cushions - The seat pans might absorb a little too -- see link below
**for reference pictures to the seat pans here's a link to a build log for the Savannah: Build Log Page 6 just click the thumbnails to enlarge.

- And finally, the biggest task in the build: I'd like to replace all the aluminum angle/longerons inside the fuselage from the firewall to behind the seats (the whole forward lower fuselage, mainly) with similar sized chromoly 4130 angle or square, so i have a chromoly cage around me. . If you check out the build log link i listed above, you'll notice that the Savannah already has an upper frame of chromoly tube, I would just want to complete the cage by replacing those aluminum angles with chromoly, then maybe add a couple reinforcements that would connect the firewall attach points/engine mount attach points on the fuselage side to the chromoly cage, . In a sentence, create a chromoly cage without a major redesign -- just use chromoly where the aluminum stiffeners/supports already were. Would that work in helping the fuselage be less collapsible in the event of a crash?

It's also worth mentioning this plane is slow. Cruise is 85-90 mph, stall is ~35 mph. So I'm not sure what my impact speed would be in the event of a stall/spin, but with such a lightweight & dirty airframe probably slower than most -- so with all of these things implemented do I have a pretty decent crashworthy spam can?

Would love some feedback. Thanks!
 
Back
Top