What to look for in an already-built -8

Hi all,

While I've spent the last few months deeply researching RV-4's, it's recently become possible to buy an RV-8 instead. So now I'm looking at already-built RV-8's.

I'm wondering if there are any specific items to look out for in a Pre-Buy inspection. In the -4, there were the firewall weldments for example - be sure they are the newer solid version, etc.

Are there any things in the -8 I need to be aware of other than SB's?

Thanks!

Buying an RV-8, things to look for.

Things I look for:

Plans built. I?ve seen RV-8?s that have been seriously modified. One had the front baggage door screwed down and it wasn?t the standard double walled door. Just one flimsy piece of sheet metal. In order to access it you had to remove the screws. When you did you would find the interior of the baggage compartment was also modified. Sheet metal was completely missing in places it shouldn?t have been missing. If the build quality is like that, I move on.

Quick builds. I?ve seen some really great slow build wings and fuselage. Don?t rule out a slow build. Look closely for trim tabs and look at the rivets. If it good, it?s good.

Leaking fuel tanks. Some leak, some don?t. Look closely at where it leaks and determine why. Sometime the pro-seal is not mixed thoroughly or in the correct ratios and it doesn?t fully setup. In other cases, the pro-seal squeezed out or there was an insufficient amount to begin with. Nevertheless, make an assessment and decide if it can be fixed and at what cost. There is some really great info on VAF on how to make those repairs and you can find some really good qualified folks who can do it for you at a reasonable cost.

Gear towers: Look closely. Some I?ve seen were significantly modified. One appeared to have been changed from a tricycle gear RV-8A to a RV8 TD. The gear towers did not sit right inside the fuselage. There were gaps and oblong holes. Pass.

Aerobatic weight 1550 lbs. vs 1600 lbs. This mattered to me. As I understand it the earlier RV-8 had a wing that designed to allow for an aerobatic weight of 1550 lbs. Then later VANS created a dash one ( - 1) wing which allowed 1600 lbs. aerobic weight. I want the RV8 with the - 1 wing. Now if I can only lose 50 lbs., then I could take an instructor up with me to teach me spin recovery, upset recovery and some beginner aerobatic maneuvers.

Canopy: A Show planes tip over canopy done like Dan Horton?s, Tom Power?s or others on this site would be the ultimate. However, can?t find one of those for sale so I have to settle for a slider. Look the slider over very carefully for fit and finish. I?ve seen some really substandard ones that do not properly mate to the fuselage when closed and have all kinds of Band-Aids on them to make them work. In my case, I?m buying an already built RV because I don?t want to build, I want to fly. So buy one with a quality built canopy and you?ll be much happier. If the seller is far away, have them send high quality photographs of the canopy all around. No cracks in the canopy either.

Prop: I want a Hartzell Blended Airfoil prop with a B Hub. Other hubs may cost you more in inspections. Don?t want to start a war. This is what I want. I?m willing to pay extra for it. Catto would also be a great choice as would others.

Battery: With a CS prop the battery may need to be in the back. Look at the weight and balance. Odyssey. No lithium.

Weight: Lighter is better. I need to lose some more.

Paint: Some are good, some are bad. Look closely. How was it prepped? Then there?s wrap. I?ve seen wrap over bare aluminum. The tanks leaked and you could see the bulging blisters under the wrap. I personally want good quality paint or no paint at all.

Engine: Parallel valve Lycoming, Titan, Superior? IO-360 counterweighted crank, low hours, good oil analysis, and good compressions. I learned on a fuel injected plane. I want fuel injection. As for ignition, conventional slick mags or Bendix are just fine for now. As long as they get inspected, repaired or replaced as need then you should be good. Check the AD and SB. Someday, maybe P-Mags. Since new as opposed to since major overhaul. I prefer since new but would consider a rebuild by a reputable shop.

Gottchas: Watch out for planes that have had the wing spars drilled to accommodate a retractable gear modification then were put back together with conventional gear. Really.

Pre-Buy: Spend the money. Get a qualified RV guy/gal with an A&P. Be there when it?s done if you can. Look over every page of the logs. Does it look like there were omissions? Lack of info. If your financing the pre-buy and logs are very important to the lender and the need to be carefully scrutinized by the buyer to determine the history of the engine and airframe. No damage history.

Supply and demand: Simple economics. The demand is higher than the supply right now. Expect to pay more. That said, some RV8?s are apparently overpriced. Just look at Barnstormers and you will see some very nice planes that have been listed above $100K for months. The ones that are priced right get snatched up quick. Be ready.

Performance: Does it make the Vans numbers? If not why?

Good luck,
Charlie

Hi Charlie,

Thanks for all that good info.

On your last point you are right..those that are priced right get taken fast...long before I can arrange a pre-buy.

There was one RV-4 that looked really good to me - when I called the next morning, someone had already put money down on it.

Used RVs

Great list from Charlie.

Three additional things I found in my search for a flying RV-8:

Many are not owned by the original builder. Get contact information and talk with the builder. Many second owners are not particularly knowledgeable.

Some are coming up to the 500 hour mag servicing. Most have not had this done. Take into account the down time and expense.

Get a look BEHIND the instrument panel. This can tell you a lot about the builder's attention to detail.

Jim
N444JT (RV-4)
N37PK (new arrival RV-8)
Both purchased flying

Some random tests to get you going, and at least sound like you know what you are doing

Ensure Flaps are motored all the way up... Now rattle each flap and see how much movement you get in each flap - should be equal i.e. as Flap Motor "stalls" at full up, it is holding both flaps against the fairings, not just one.

Move to one wingtip, and align Aileron outboard end with wingtip: view down Trailing Edge and check how "in-line" and straight the Wingtip - Aileron - Flap are.

Leave Ailerons in that position, and look down other wing, do likewise.

Will give you a quick assessment of how much effort went into the building and setting up of the wing and surfaces. Some "errors" in this are just re-rigging, but most would require "surgery".

Poor alignment might not mean "no buy" but definitely a bargaining point

Ditto on Flight Test, look closely at how balanced aircraft is in roll and yaw at a variety of airspeeds. Difficult if an aileron trim is fitted (ideally you would fly with it & springs disconnected) - but at least ensure Aileron Trim does not need altering across the speed range. Yaw/Rudder will require standard high/low speed pressure, but should be "in balance" at a typical cruise / mid-speed.

On Flight test, prior Takeoff set trim visually to "in-line" (Dual) ~1/2" TE down (Solo) with nil baggage. If Electric pull CB. Takeoff and at 80-90K release stick pressure - is aircraft in trim? If significantly out of trim I would suggest you have a rigging issue, or unusually forward/aft basic CG.

Elevators: as above, clamp one elevator horn to HS and ensure other elevator horn is exactly in line with HS.

Wheel Spats (Pants!): on level ground, measure distance from aft edge to ground to ensure equal.

Andy,

Thanks. Great points to consider. This is now on my to do list.

Charlie

Jim,

My list was actually generated from notes taken from conversations with you and others on this site.

Thank you so very much for the education everyone. This is an awesome site.

Saville,

Some of the best advise I got and really needed was to be patient in my search (Jim thank you) to find and buy an 8. The right plane will come around at the right price. I will keep my eyes peeled and forward to you any viable leads.

Chkaharyer99 said:

Jim,

Saville,

Some of the best advise I got and really needed was to be patient in my search (Jim thank you) to find and buy an 8. The right plane will come around at the right price. I will keep my eyes peeled and forward to you any viable leads.

Click to expand...

Chka,

Thanks and yes it is an awesome site. I'm looking for a middle machine not high end.

As I wrote in the Classifieds my "Must Haves" are:

180hp
C/S prop
Fuel Injection
(either IO-360 or after market systems like Airflow Performance, Bendix,
etc. No Ellison TB)
Day/Night VFR
All SB's must be complied with.

I would prefer one with an Artificial Horizon or a Dynon D-10A.

I do not need megaloads of high end avionics. So while it's not a low end machine (e.g. 160 hp), it's a low-to middle.

Many thanks!