X-Fly Su-27 Flanker Update

[Mike Freeman]

I've been flying the Su-27 reviewed in the Sept '22 issue quite a bit since I sent the review in and thought I'd update everyone on a few mods and a confession!

First up, here are a few more flying shots that were taken too late to be considered by Kevin for inclusion in the article.  The photos included in the review were taken with the recommended CG which turned out to be waaaaay too far forward.  Clubmate Pete Searle was on the sticks whilst I was photographing and he had a terrible time with the nose digging in whilst banking and was reluctant to fly too low for the camera.

Once the CG was moved back the Su-27 became a joy to fly and on a subsequent meet up with my brother, Al (who lives in Derbyshire) we got some more flying shots which are included here.  We were flying "Mach Loop" style fly pasts up from the valley below our flying field. Great fun it was too!!  Al also took a short video clip of a hand launch which shows how easy the Su-27 is to hand launch.  

[Mike Freeman]

And now, the confession...

The following paragraph was originally in the article but subsequently removed to save space.  I told Kevin I'd 'fess up once the article had been published so, here goes...

 

"Sadly the maiden flight ended in disaster! Club mate Pete was on the sticks whilst I was on the camera and after a rather long 40 metre roll out the Su-27 hit a small bump and was safely away. All was well until Pete moved the ailerons… “The ailerons are reversed”, he shouted and the Su-27 ploughed in, snapping the nose off at the back of the cockpit. The nose wheel and one of the mains was also ripped out. Pete had no chance! From the nose wheel back there were just a few scuff marks and wrinkles. This is one strong model!! I was sure I’d checked the throws and directions several times whilst setting up and I can’t believe I had been so stupid! Thankfully the model was quickly repaired (with just 12g added weight) and soon back on the patch… with the aileron directions correct this time!!"

 

To this day I don't know how I missed this fundamental error but seconds after this photo....... it all became too clear!!

 

The next photo shows the resulting damage which, considering the speed she ploughed in, isn't really that bad!! 

 

I glued the nose back on with UHU POR glue and pulled it up tight with a former and strings working like tent guy ropes to hold the nose in line.  I fitted the canopy to make sure everything was aligned properly.  I also glued in some 1/64" ply doublers to strengthen the joint.  Finally I got some match pot paints mixed at B&Q which match pretty well!!  The flying shots in the review are the repaired model!!

[Mike Freeman]

The nosecone is quite vulnerable on this model and I must have repaired the original 3 or 4 times before I remembered an article I wrote in the May 2002 issue of Q&EFI (can I mention that here? 😬) where I made an EPP spinner covered in a balloon.  I did the same thing on my Su-27 and the result works fine so far and is a few grams lighter too.  I need to find a slightly darker balloon but this will do for now.

The following photos should give you the idea, reply to this post if you need any further info.

 

 

 

 

 

 

 

 

 

[Paul De Tourtoulon]

Ailerons reversed, isn't their a topic on that ?.🤐

[Paul Johnson]

On 11/09/2022 at 14:06, Mike Freeman said:

I've been flying the Su-27 reviewed in the Sept '22 issue quite a bit since I sent the review in and thought I'd update everyone on a few mods and a confession!

First up, here are a few more flying shots that were taken too late to be considered by Kevin for inclusion in the article.  The photos included in the review were taken with the recommended CG which turned out to be waaaaay too far forward.  Clubmate Pete Searle was on the sticks whilst I was photographing and he had a terrible time with the nose digging in whilst banking and was reluctant to fly too low for the camera.

Once the CG was moved back the Su-27 became a joy to fly and on a subsequent meet up with my brother, Al (who lives in Derbyshire) we got some more flying shots which are included here.  We were flying "Mach Loop" style fly pasts up from the valley below our flying field. Great fun it was too!!  Al also took a short video clip of a hand launch which shows how easy the Su-27 is to hand launch.  

Hi Mike, know this thread is 2022. I just put my SU27 together, you mentioned the C of G was too far forward, what C of G datum did you use ? Also, what control surface movements did you use - sorry for all the questions. 

Paul 

[Mike Freeman]

Hi Paul,

Sorry for the very late reply, I've been away.

I ended up moving the CG 15mm behind X-Fly's recommendation! As spec'd I found the model almost impossible to fly!! I know manufacturers quote "safe" CG's but this was way too far forward!!

I found the take off run extremely long, even with the better CG so I upped the elevator throw by 2mm and linked it to a flight phase to help get the model off the ground. Once airborne the recommended throws were ok for me.

In the end I took the u/c off, whipped the nose wheel servo out and now hand launch it.  It looks so much better without the gear dangling down!!

 

Good luck

Mike 

Edited September 5, 2023 by Mike Freeman
Spelling mistake