Official Freewing 80mm A-4E/F Skyhawk Thread

[crxmanpat]

Some nice looking Scooters there boys, and congrats on the maidens!

[seaviper]

Started working on the tail

I painted the rudder then cut and applied the white part of the Callie Graphics vinyl. I had to make up a couple of custom pieces on each side of the rudder as the original graphic did not entirely fit. But this is the only way I could figure to do those white spaces.

[EDFjetpilot]

Finally got my maiden in this last week, then put another 18 flights on it during the Fall Jet Classic. I too dialed down the ailerons to about 6mm of throw.

I flew with the Roaring Top 5000/70Cs and 6250/35Cs. The 5000s (770g) were 35mm from the front foam stop of the battery tray. The 6250s (803g) were in line with the front edge of the forward battery strap cut out.

With calm wind and half flaps, I could turn base, cut the throttle and glide it in power off. With a little wind, I carried about 10% throttle to touchdown.

Good 4 minute flight with the RT 5000s, and 5 minutes on the 6250...using 60-75% throttle with a few WOT passes and climb outs.

Sean

[RCjetdude]

Started working on the tail

I painted the rudder then cut and applied the white part of the Callie Graphics vinyl. I had to make up a couple of custom pieces on each side of the rudder as the original graphic did not entirely fit. But this is the only way I could figure to do those white spaces.

It turned out great! Good job. :Cool:

[dahawk]

Edf ,
For the 6250, was that mark at the front of the strap to achieve the recommended 195 cg ?

[RCjetdude]

Finally got my maiden in this last week, then put another 18 flights on it during the Fall Jet Classic. I too dialed down the ailerons to about 6mm of throw.

I flew with the Roaring Top 5000/70Cs and 6250/35Cs. The 5000s (770g) were 35mm from the front foam stop of the battery tray. The 6250s (803g) were in line with the front edge of the forward battery strap cut out.

With calm wind and half flaps, I could turn base, cut the throttle and glide it in power off. With a little wind, I carried about 10% throttle to touchdown.

Good 4 minute flight with the RT 5000s, and 5 minutes on the 6250...using 60-75% throttle with a few WOT passes and climb outs.

Sean

Dag I love me some Blue Angels A-4's. Got an ARF+ on the way to make mine. Where is your CG at? Are you at the 195mm with gear up as defined in the addendum? I maidened mine today and I felt like it was too tail heavy. Fairly pitch sensitive even with the elevator throw turned down. Upon lift off it shot almost straight up and I immediately pushed the nose down. It responded and levelled out but was a handful to get back on the ground. I think I am going to move my CG forward a little bit and try again.

[dahawk]

RC,

Your incident is almost exactly what I saw happen to my buddy's A4 today. He's a very good jet pilot. Fly's turbines mainly.

Take off roll on grass was looking real good. Rotated at about 150 ft. Then went straight up and stalled as he was trying to get the nose down. First thought was that he had it and it would level her off and power out of the stall. She turned on her own back towards us still with low air speed. He managed to raise the gear before she went in. Way tail heavy.

Damage not bad . Departed fuse at a seam near starboard intake. Easy glue job. Refueling probe speared into the ground. Nothing bent out of shape.

We had checked Cg on the table. He was using a RT 5000 70C. Was balanced at 195.

Still scratching our heads.

Hawk

[EDFjetpilot]

Regarding my CG, I'll have to measure and get back with you guys once I return home from the FJC. I literally didn't measure it and placed my RT 5000/70C an inch back from where guys said they were placing their Admiral 5000s for my maiden (having used Admirals in the past in other planes, I determined the RTs needed to go about an inch to the rear to get the same CG). When I initially finger balanced at the 195 point, my 5000s were way back on the battery tray and that didn't make sense based on other's flight reports. Thus, I thought the 195 would be tail heavy. So I started with my inch reference and pushed it back from there figuring better to be nose heavy than tail heavy.

Hawk...I think I know who you're talking about. And based on the pic he sent me on his battery placement to reach 195, it was about an inch and a half further back than where my RTs are placed. He's now thinking the CG should be 180.

Again, let me get a good measurement and get back to you guys.

Sean

[roys001]

I got the Scoter put together with decals from Callie and got it to the field yesterday. I was lucky enough to have xplaneguy at the field. He was kind enough to help out with the maiden. It flew great. Wonderful airplane. Files very nice at half throttle and of course full throttle is amazing (IMHO).
Needed a few clicks of up and a couple of right but other than that it was great. I got 3 flights on the plane. Of course the fist landing was the best.
One note I would like to add. The design of the full size bird has has an inherent weakness. Slow tight turns are NOT your friend. You MUST respect that this plane likes power through the turns.
I really like this airplane. I'm using factory specs for surface movement with the exception of the ailerons. For now I have them dialed back set to 50/75/100 for low, medium, and high rate. I'm flying with 50. The CG is set to the new numbers provided earlier in the blog. I may play with that a bit after I get some more time on the bird.

[seaviper]

rcjetdude...what battery are you flying? If it's the new Admiral 6s 5000 (the longer lighter one, not the brick), then just push it up to the circuit board in the front. It will fly like a dream.

[RCjetdude]

rcjetdude...what battery are you flying? If it's the new Admiral 6s 5000 (the longer lighter one, not the brick), then just push it up to the circuit board in the front. It will fly like a dream.

RT 5800 35C and my board, receiver and an A3L are all mounted under the battery tray. The front of the battery was about 1/4" from the foam lip. Plus, when I balance a low wing bird, I balance it upside down and I did it with the gear down. No disrespect to anyone but with the gear all going forward and up I do not want the CG any further back than 195 and that would be when the gear are down. I did notice it was a little less pitch sensitive with the gear up.

[seaviper]

Yeah i dont know where they got the "gear up" idea. Anyway my board and rx are all up front and my batt is up against the fwd bulkhead.

I had the same thing happen to me on the t45. Moved the batt back 5mm and she was a handful.

[Kloverzero]

While this is not the best takeoff I have ever done, here is a video of my A-4 from the weekend flying from our grass field in Florence SC. The grass is very thick and luscious at this time of the year, yet the A-4 handles it just fine. This was my second flight on the plane. After this flight, I put some zip ties on the nose strut oleo to defeat the piston, and keep a positive AOA on takeoff roll. It worked even better this way in the grass, but unfortunately, I did not get any video of the two subsequent flights (which had MUCH smoother takeoffs!!!!)

https://www.youtube.com/watch?v=IsYVcoVRO40&t=70s

[dahawk]

Great vid and nice flying. Really shows the flight envelope.

Hawk

[The RC Geek]

Well, it was a bittersweet weekend at the field on saturday. I had noted in my initial write up about the airplane pitching up with the flaps down near stall speed. Well, I decided to move the CG forward and see what that did and it completely got rid of that pitch up tendency and the airplane lands absolutely perfectly now! I had originally CG'd the airplane at the 195mm mark but am now forward of that. For reference, I'm using a roaring top 35c 6s 5800 pack that's pushed all the way forward to the servo board in the nose. So, just a heads up if you are experiencing anything like that. I didn't notice any other differences in flight by moving the CG forward, just the improved landing characteristics.

I say bittersweet because on the 4th flight of the day with the A-4 I unknowingly put an already flown pack into the airplane (DOH!). About a minute in, the fan quit and I was low and on the downwind and went down in the bush. The airplane survived quite well actually with only a few creases around the airframe mostly, but it decimated the nose gear retract. I've already ordered the replacement parts I need to get her back in the air so, I should have the airplane going again soon. Though, I'll go through and do all the painting and mods I had planned while I'm getting it all back together. Thankfully there was minimal damage it's mostly all cosmetic damage having a few creases in the fuselage and a couple small dings in the wing. She'll be better than new when I'm done! ;)

Before all that happened, I had done a few cockpit upgrades last week and so wanted to share a few pics.. I replaced the pilot with one of my Castle 5 (1/10 scale) busts (available from jethangar.com) and then did a little treatment to the seat with some spare parts I had from my Jet Hangar A-7 stash. Last thing I did was to add a card stock hood over the instrument panel. No more popcorn here! The stock seat is too far forward and just way too small in the stock tub, so I actually moved it back about 1/4+" which helped get it to look more correct. That along with the addition of the ESCAPAC II head rest really improved the looks of the cockpit area.


Chris

[seaviper]

Chris sorry to hear about the A-4. I'm guessing the battery is toast? Nice job on the cockpit. I may order some of those pilots from you guys. I just HATE painting them.

[The RC Geek]

Chris sorry to hear about the A-4. I'm guessing the battery is toast? Nice job on the cockpit. I may order some of those pilots from you guys. I just HATE painting them.

The battery should be fine, but I'll keep an eye on it. I immediately put it into storage once I got back to the pit area. It was showing a little over 3.3v/cell.

[dahawk]

Regarding my CG, I'll have to measure and get back with you guys once I return home from the FJC. I literally didn't measure it and placed my RT 5000/70C an inch back from where guys said they were placing their Admiral 5000s for my maiden (having used Admirals in the past in other planes, I determined the RTs needed to go about an inch to the rear to get the same CG). When I initially finger balanced at the 195 point, my 5000s were way back

Hawk...I think I know who you're talking about. And based on the pic he sent me on his battery placement to reach 195, it was about an inch and a half further back than where my RTs are placed. He's now thinking the CG should be 180.

Again, let me get a good measurement and get back to you guys.

Sean

Yep, name withheld to protect the innocent- lol

[seaviper]

Mission ready! Still have a bunch of detailing to do. But for now she looks better than plain ole haze gray.

[roys001]

Well, it was a bittersweet weekend at the field on saturday. I had noted in my initial write up about the airplane pitching up with the flaps down near stall speed. Well, I decided to move the CG forward and see what that did and it completely got rid of that pitch up tendency and the airplane lands absolutely perfectly now! I had originally CG'd the airplane at the 195mm mark but am now forward of that. For reference, I'm using a roaring top 35c 6s 5800 pack that's pushed all the way forward to the servo board in the nose. So, just a heads up if you are experiencing anything like that. I didn't notice any other differences in flight by moving the CG forward, just the improved landing characteristics.

I say bittersweet because on the 4th flight of the day with the A-4 I unknowingly put an already flown pack into the airplane (DOH!). About a minute in, the fan quit and I was low and on the downwind and went down in the bush. The airplane survived quite well actually with only a few creases around the airframe mostly, but it decimated the nose gear retract. I've already ordered the replacement parts I need to get her back in the air so, I should have the airplane going again soon. Though, I'll go through and do all the painting and mods I had planned while I'm getting it all back together. Thankfully there was minimal damage it's mostly all cosmetic damage having a few creases in the fuselage and a couple small dings in the wing. She'll be better than new when I'm done! ;)

Before all that happened, I had done a few cockpit upgrades last week and so wanted to share a few pics.. I replaced the pilot with one of my Castle 5 (1/10 scale) busts (available from jethangar.com) and then did a little treatment to the seat with some spare parts I had from my Jet Hangar A-7 stash. Last thing I did was to add a card stock hood over the instrument panel. No more popcorn here! The stock seat is too far forward and just way too small in the stock tub, so I actually moved it back about 1/4+" which helped get it to look more correct. That along with the addition of the ESCAPAC II head rest really improved the looks of the cockpit area.


Chris

Interesting RC Geek. I balance the plane from the point where you slide in the guns. When I put down the flaps, the nose pitched down a lot more than the suggested up elevator/flab mix suggested. Based on your experience I wonder if I should move the CG back a bit and see if it eliminates the nose pitch. Thoughts?