VAF Forums

VAF Forums (
-   RV General Discussion/News (
-   -   Another RV8 First Flight (

Chris Engler 05-29-2018 08:39 PM

Another RV8 First Flight
After 5 1/2 years the airplane and I had a near perfect first flight yesterday! Winds were calm, some rain showers had passed through and the afternoon high temps had cooled to mid 70s. After some marathon sessions at the hanger these past few weeks tweaking, checking, rechecking, by around 6:30 PM yesterday, I had that strange "there's nothing left to do" feeling so I called the camera crew (aka my wife), pushed it out of the hanger, and did the pre-flight.

Started the engine, taxied to the end of the runway, completed the mag check and takeoff checklist. With everything in the green, took the active and advanced the throttle. The airplane tracked perfectly and with about 60 mph indicated, nudged the stick back and it was airborne! The thing that surprised me the most was how solid everything need for trim on either axis and just locked on the heading. Got to about 5000 feet in very little time and throttled back to check response at slow cruise - all good. Then slowed down to low 60s with flaps to check slow speed handling....again, completely straight and predictable. After 20 minutes or so, went back to the airport to set up an approach. Bounced a bit on the first landing (the typical pulled power to idle early and flared a bit too soon) but a blip of throttle settled it in. What amazing airplanes these are!

Went back out today and flew to a couple of local airports and filled the tanks....a couple hours in and feeling very comfortable.

One of the things I was concerned with during the build was cooling. The engine is an XP 400 but between the large oil cooler using the RV10 firewall mount and tight fitting baffles, the highest temps I've seen on climb out is around 190 (ambient temps around 80 today).

Of course some thanks are in order....first to this great community for providing the massive knowledge base to help with those head scratching moments. I don't have any active builders nearby but help was always only a post or search feature away. Not sure if a day has gone by during the build that I wasn't logged on at some point. Next, a big Thank You to Bryan and Showplanes. I used his fastback conversion and cowl and have been delighted with both products. More than that, I've lost track of the number of times we chatted over the past 5 years (even RV8 questions not related to his products). Whenever I'd call I get hear the same steady and calming voice offering years of wisdom from one of the great builders....never rushed and happy to send pics to help explain his answers.

Lastly and most importantly a BIG Thanks to my wife! Regardless of all of our lots in life, building and airplane is a big commitment in terms of both time and money and I was very fortunate to have complete support in both regards.

If the weather cooperates, hoping to get the 40 flown off in time to see some of you and Oshkosh this year! :):)

I'll see if I can get some pics posted soon...and change my signature from "Under Construction" to "Completed"!

Mike S 05-29-2018 08:41 PM

Chris, big congrats on the new fledgling:D

Show Planes makes some nice stuff.

Now we need photos...........

Chris Engler 05-29-2018 09:13 PM

Thanks Mike....and now for the pics...

xblueh2o 05-30-2018 05:55 PM

Always good to see another fastback. I have not had much chance to work on mine the last few months.
The cockpit shot. Was that taken pre first flight? I notice some missing hardware on the rollover protection.

AAflyer 05-30-2018 07:44 PM

Now, THAT looks FAST!!!:eek:

carlrai 05-31-2018 04:51 AM

Great Job!
Well done Chris, especially like the fastback. Nice clean panel too.
Grew up down the road (Rte 12) from you in Norwich.
Currently flying a 9A and buttoning up the wings on an 8.

Curious if you have any build photos posted, specifically the fastback mod.

David-aviator 05-31-2018 09:56 AM

Congrats on first flight and welcome to very special club of those who have built and flown an RV, especially the RV-8. :)

Chris Engler 05-31-2018 09:05 PM

Good eye on the missing screws Sam....that pic was taken a few days before the first flight. Took the pic below today showing the top attach screws in the rollover bar mount and they were one of the last things I did....the middle screws in back are a bit of a pain to get in!

Bruce....yes, still creeping up on top speed numbers....was seeing 192 TAS at 11,000 feet yesterday with the prop and mixture set for economy cruise (9 gph or so). I was only getting 2550 rpm at the fine pitch setting so adjusted the govenor today to get to 2700...low overcast in upstate NY so haven't tried yet but will be anxious to get numbers at 8000 with all the levers forward (other than fuel flow:eek:)!

Thanks Carl....our kids all went to Greene HS so spent many an evening in Norwich for varsity football and basketball games. I flew into Norwich airport with the 8 Tuesday evening while I was out sight was the typical quiet night there.

I don't have a build site but took a few pics today of some of the fastback features. The things I like best are:

1. Great access to the avionics area behind the panel but removing the cover.

2. The completely unobstructed view out the canopy (no bar in front).

3. The larger rear baggage area compliments of the raised turtle deck

Here's a pic of the panel with everything on....still learning the finer points of all the capabilities.

David - yes, I've always loved the 8 and glad to be in such fine company!

DanH 06-01-2018 06:21 AM

Congratulations Chris!

Couple notes...

Long time ago, a very qualified fellow was kind enough to share FEA models of the rollbar. The assumption made for analysis is that the aircraft might still have some forward velocity after a flip, sliding tail-first in the original direction of travel, which would tend to bend the rollbar hoop forward toward the pilot. The models showed what we might expect. A plain hoop added to the stock Vans mid-cockpit crossmember was very weak. A braced hoop was better, but not optimum. The best solution was two hoops, added at the base plates. 'Nuff said.

Max speed will be down on the deck where you can develop all the 400's HP.

Next flight, note that it's easy to bump the yellow canopy release knob with an elbow, or perhaps catch it with a sleeve. If that lever goes forward in flight, the canopy is gone. After bumping it enough times to scare myself, I added a secondary blocking device so the lever cannot be moved forward accidentally.

Watch the rearmost rivet in the piano hinge. I found it necessary to replace it with a screw and nut.

Question for you; does the Showplanes cowl offer some space above the forward corner of the #1 and (in particular) the #2 angle valve cylinder heads? It's very tight with a stock cowl.

Chris Engler 06-01-2018 08:25 PM

Thanks for the advice Dan. We met at the Virginia fly in last year and I took numerous pics of your airplane for inspiration and motivation...just what I needed down the home stretch! I'm sure that long cantilevered hoop would result in some high loads on the attach points so I'll give some thought to reinforcement.

I did manage to fly today after tweaking the governor and was up to 2650 so need just a bit more travel to get to 2700....hopefully this weekend. I'm new to the world of CS props so still getting the hang of that but seems great to have that extra dimension of control over engine operation. I was surprised to see how much effect altitude had on limiting manifold pressure.

My canopy lever is still a bit stiff but will likely loosen up with some hours so will have to watch that closely.

Regarding the clearance with the SP cowl, it depends in part on how "short" the cowl is cut. I likely went a bit overboard trying to keep mine short with the intent of limiting the length of the prop extension and thus my #2 cylinder flange clearance is tight. So much so that I had to move the baffle on that side to the inside edge of the flange rather than the outside. It seems to work fine but if I pushed the cowl forward another inch or so, it would provide better clearance. I ended up with a 2 1/4 inch extension and my spinner-cowl gap 3/16th.


All times are GMT -6. The time now is 07:13 PM.