Silverhawk fittings

[LettersFromFlyoverCountry]

Originally Posted by C-GRVT

This question of Bob's is directly connected to the very valuable recent Van's comment on safety and related thread. We all have to get the firewall forward stuff right!

That's one of the things that has concerned me greatly is how LITTLE information there is about firewall forward material easily catalogued and organized (I miss you, Tony Bingelis). I mean, sure, if you spend months patrolling all the various spots and you happen to catch the correct thead, you can get a shred of it and then add it to all the other little shreds. A checklist of tasks for engine installations, for example, would really be a step in the right direction.

Remember when we first drilled HS410 and HS414 way back when we started these things. Remember how careful we were? That's the same attitude we need to bring to firewall forward.

I don't know one O-ring from the other. I obviously don't know one fuel servo fitting from the other and you can repeat this infamiliarity from one component to the next in the engine compartment. The problem isn't that I don't know how to get that information; the problem is I don't know what I don't know.

This is a pretty important part of the overall project and I appreciate Van's safety letters, but the fact is at this part of the project, Van's kinda says "you're on your own. Good luck." I can certainly see why; there are too many varying installations to be able to do anything but leave it to the builder to figureo out.

The information that Don has provided here, it seems to me, is invaluable, and it concerns me that the way a typical builder would learn it is a total crapshoot of luck and serendipity. Which is a bit of a shame because this is wayyyy more important than primer. (g)

[C-GRVT]

I don't criticize Van's for not providing a paint by number or step by step for firewall forward. Even if he did it would not address important "gotchas" that relate to workmanship and technique.
I am now working firewall forward and fuel system plumbing (IO-360, vertical induction, AirFlow pump, Lightspeed ignition).
Are the hoses properly supported, how close can they be to an exhaust, what sealant if any should I use for an oil line, for a fuel line, how does that o-ring fitting get tightened? (thanks Don, now I know (except for how tight the lock nut should be), and it does makes sense.
When I make an aluminum fuel line with a Parker Rolo-Flair, what do I look for to make sure that the flare is done properly and won't crack or break after it is installed? Is that short aluminum line that I see some people have installed from a fuselage bulkhead or wing root gascolator to the tank at risk of cracking as a result of wing/fuselage flex? Or is that a silly concern.
This building thing is by definition in part for education - I get that and it is part of the appeal - but the consequences of getting any of this wrong contribute directly to the statistics we are trying to improve upon.
Reducing accidents from construction errors should be low hanging fruit. Unlike changing attitudes about, for example, flying single engine at night where reasonable people may reasonably disagree about what constitutes an acceptable risk, I am sure that nobody thinks flawed workmanship in a flight critical system is acceptable.
I am not an A&P mechanic but I am building a plane and want to do it right.
I will have inspections, but not everything can be easily inspected. I know I would benefit from a resource (a book, series of articles, whatever) that addresses the things every builder comes across. I think the safety stats would too.
Bill Brooks
Ottawa, Canada,
RV-6A finishing

[Lars]

Since I stepped in this one with my first post, here's some information to augment Don's last reply.

The Parker O-ring Handbook is the Bible of seal engineering information, except unlike the Bible, they used to be hard to get. Mine is 25 years old; I had to beg for it and I don't let it out of my office. Except like so many handbooks, now it's available online.

It's pretty obscure for the non-technical user, and even for the more technically minded, there's a lot there. Still, it decodes the numbering systems that specify o-rings, and that can be helpful.

Here's a photo of the AN833 fitting that came off the outlet port of my fuel servo. You can see the groove Don mentioned, and the o-ring and nut. Note that in this case the o-ring is riding on the threads. That's how the fitting came off my servo. Not good. That would probably have leaked. The o-ring is supposed to be in the groove.



Expanding on the posts about lack of FWF knowledge... My gripe related to this topic is that, despite 25+ years of experience with hydraulic fittings, o-rings and seal design (but not in aviation) I'd never heard of using what I considered bulkhead or union fittings for o-ring seal applications. And if you buy one of those fittings from Aircraft Spruce or other sites frequented by homebuilders, they don't come with the correct o-ring, nor is there any reference to it. And I still wouldn't have known if I hadn't responded to this thread, leading to Don Rivera's timely reply.

I'm lucky that my combo of engineering experience and lifelong hobbies of auto and motorcycle wrenching have had given me some cross over to aviation, but obviously there are still big (and potentially dangerous) holes in my knowledge. Trying to get this done with no technical background must be really intimidating.

[C-GRVT]

Lars,
thanks for the reference - I don't mind the learning, it is not knowing whether I have it right and am not missing something. I consider myself fairly mechanically adept (restored old British cars, rebuilt engines etc..) but aircraft have their own technologies and systems, and of course failure is more than pulling off to the side.
Bob, I apologize for the massive thread drift!
Bill Brooks
Ottawa, Canada
RV-6A finishing
(Hartzell installed for first time)

[LettersFromFlyoverCountry]

This was an unbelievably helpful thread. Thanks to everyone who contributed. A cold bucket of water and a ton of education.

[Don at Airflow]

Well, we do offer a Fuel Injection 101 class twice a year. In this 2-day session we cover all the intricacies of fuel injection systems, and their installation. These types of issues are covered in the class. But hey, I guess everyone knows this stuff because we canceled the spring class. No one signed up. Next class is the first weekend in November 4-6.

Any takers???

Don

[Ironflight]

Originally Posted by Don at Airflow

Well, we do offer a Fuel Injection 101 class twice a year. In this 2-day session we cover all the intricacies of fuel injection systems, and their installation. These types of issues are covered in the class. But hey, I guess everyone knows this stuff because we canceled the spring class. No one signed up. Next class is the first weekend in November 4-6.

Any takers???

Don

Hey Don - how about updating your profile (and/or signature) to show your location? Anytime I see something that might be interesting (to see, do, or buy) on the forums, I check to see if it is something within a reasonable distance. If others are as lazy as I am, they might not take the effort to do a search to find the link to your company or where you are. That might affect how many people sign up for the class. I'd love to see something like this - I find fuel injection training manuals to be hard to follow.

Paul

[Lars]

Originally Posted by Don at Airflow

Well, we do offer a Fuel Injection 101 class twice a year. In this 2-day session we cover all the intricacies of fuel injection systems, and their installation. These types of issues are covered in the class. But hey, I guess everyone knows this stuff because we canceled the spring class. No one signed up. Next class is the first weekend in November 4-6.

Any takers???

Don

I would love to attend- from the description on your website it sounds like a great course. Time and especially distance is the problem for me, at least right now while I'm building (siphoning off all excess time and money). Eventually though I hope to make a point of it.

[LettersFromFlyoverCountry]

Originally Posted by Don at Airflow

But hey, I guess everyone knows this stuff because we canceled the spring class. No one signed up. Next class is the first weekend in November 4-6.

Any takers???

Don

Sarcasm aside, I don't think you're understanding the view of the non-expert builder who's working like crazy to try to pull information from a million different places in order to keep from burning alive in an airplane thousands of feet above the ground.

I'm sorry nobody showed up but I can assure you it has nothing to do with with everyone knowing this stuff. My guess is they didn't know about it. Obviously they do now.

It's an underreported and unacknowledged fact of airplane building that the builder has to work VERY hard to gain all of the knowledge that's required to properly build an airplane. It's not in the best interest of the kitmakers to tell you this up front.

But, as I said earlier, if you don't know what you don't know, it's mighty hard to know what to do about it.

I know people pooh-pooh the idea of some sort of checklist of major things people need to know, especially firewall forward. I get it. It's a "real airplane builders don't use checklists" mentality. But people either want these things to stop crashing, or they don't. And it would be a great first step if the best and brightest RV builders in the business could put their heads together and come up with a page on a Web site -- this one perhaps? -- that says: "These are the steps you need to follow in this process and here's a link that has all the information you need on this particular component."

I mean, just look at this thread -- O-rings and the importance of using the right one. Multiply that by 100 different potential causes of problems and the challenge is obvious.

It would be a great step toward improving the safety of homebuilt airplanes.

[Don at Airflow]

Bob, there is no place for sarcasm here. This is ?deadly? serious stuff. I understand what you mean, but it is kind of like me diving into the workstation here at my desk cause it doesn?t work or putting ?signature? to show my location. What does that mean? I don?t have a clue about how computers or programming work and don?t really want to know, just that it works when I turn it on. But even though I don?t care to work on electronics (why do you thing we build mechanical fuel injection systems) I am forced to learn how to program a SDS fuel injection and ignition system on a Rotax. With my limited knowledge of automotive computers, this is a large task. Just figuring out how to get into the program is a dilemma; there are 86 pages of stuff to read. For a computer savvy dude or a 14 year old it?s probably cake, for me it?s a pain. I?m not even going to try getting into the EFIS to add some new parameters like MAP (it?s a turbo charged engine and there wasn?t any MAP read out. Stuck a 2 ?? MAP gauge in the panel, problem solved). Man I love the mechanical stuff.

But in any case as I said before there are many people who frequent this forum who have specific knowledge of certain subjects. If you don?t know, ASK. It?s probably a lot easier than trying to sift through the chaff to find the correct answer on the Internet or going to the library. I guess I?m still back in the 60?s. When my Dad and I started building our Starduster Too there was a set of drawings to build the structure and then it was pretty much your own doing. Systems especially. But back then most people that built homebuilt airplanes already had a background in aircraft and many were A & P?s (A&E then). As far as information goes for fuel systems we have compiled a 180+ page manual for our fuel injection system installations. You can purchase one if you like or you get the manual free if you purchase one of your fuel injection systems. I see you have chosen a Precision fuel injection system, so you best source of information pertaining to Precision fuel injection systems and their installation is Precision themselves. Here is their phone number. 360-651-8282.



Don
We are at KSPA