Ed Anderson
Joined: 10 Jan 2006
Posts: 475
|
 Posted: Wed Mar 05, 2008 2:57 pm Post subject: The Risks: was : Subaru down |
 |
|
| Quote: |
I agree that people installing alternate engines or propellers need
to have a realistic understanding of the increased risks they are
undertaking. But, if they really do understand those risks, it is a
bit presumpstious of us to try to tell them to install a Lycoming
instead. After all, the accident rate during the flight test phase
on RVs is quite a bit higher than the first 40 hours that a new owner
does in his Cessna. If we are really concerned about risk, why
aren't we all flying Cessnas?
|
> Kevin Horton
Well put, Kevin
I have flown my rotary powered RV-6A for 10 years now. There is no question that there is an added element of risk when you are performing your own Design, Research and Development and Testing rather than relying on a company who has spent $$$$ on same.
I go back far enough when I can remember when the GA crowd considered anybody building/flying an experimental a bit crazy. Now the alternate engine guys are considered crazy by many of the experimental aircraft crowd - so I guess that makes us a subset of the crazies {:>).
Building "experimental" aircraft is nowhere near the risk it used to be thanks to a number of well proven designs to choose from. Lets face it - most experimentals flying now are really assembled kit-planes including mine. However, experimental engines have been part of experimental aircraft going back to the Ford powered pietenpol and beyond. Given the increasing cost of certified engines it is not surprising that some probably set on the alternative engine track thinking they are going to save a bunch of money - you can install a safe alternative engine for less than a new Lycoming, however, if you consider a rebuilt Lycoming (for example) then the price differential can narrow considerably.
In all seriousness, rolling your own engine installation requires knowledge, understanding and execution in a number of different areas where anything less than getting it correct can be "rewarded" with that dreaded dead silence after take off. My personal opinion is that there are two classes of folks who are currently installing alternative engines. Those who "roll their own" and those who purchased FWF kits. Most (but not all) who attempt to "roll their own" quickly realize the magnitude of the task required to design, conduct FEMA, fabricate, install and successfully test and operate all the required subsystems either buckled down to the task OR realize the task is beyond their knowledge, experience and skill level and go to other options.
One option is to purchase a FWF kit - nothing wrong with that in itself - but, one must realize that no alternative engine provider that I am aware of has the decades of information that a certified engine manufacture does to make their design safer over time. So if you recognize that as an individual that you perhaps do not have the knowledge and skills to tackle a "roll you own", then the question is "Do you have the knowledge to adequately assess the FWF alternative engine kit you are considering?" Even then you still have to install the package successfully.
We all know that even given the 1000 of installations of Lycomings in RVs that there are still an unfortunate few who encounter that dreaded period of silence - it does not take much of a mistake or error for that to happen. It is much easier for that mistake to happen with an non-standard installation of an alternative engine - where yours is likely the first such installation. Some people have attempted to alleviate there lack of knowledge by "copying" another successful installation of an alternative engine - one thing we have found out is that unless it is an exact duplication in every aspect - its a completely different system and may have failure modes induced with each and every change made that differ from the "successful" installation. .
I have had numerous discussion over the past 10 years with individuals about the advisability of putting an alternative engine in their project. I normally attempt to discourage such attempts. Even with my successful 10 years of flying behind a rotary, there were times, particularly in the early days, when I wondered why in the h---- I didn't just stick a Lycoming in the bird.
I tell folks that if you really like to experiment, are something of a GearHead and can put up with repeated frustration and problem solving then an alternative engine might be your cup of tea. However, if what you are really interested in is flying - then do yourself a favor and install a Lycoming (or equivalent) and go enjoy flying.
But, if you are going to go down the alternative road, do yourself a favor and sign on to the email list of your favorite candidate engine (these list are out there), lurk, ask questions and listen to get an idea of what you are considering chewing off. Its very easy to make a claim - check into any such claims, ask tough questions - its your butt you'll be risking. Remember what you mom told you "if it sounds too good to be true......"
Just my opinion of course
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson(at)carolina.rr.com (eanderson(at)carolina.rr.com)
http://www.andersonee.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda/index.html
[quote][b]
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
_________________
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com |
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
