Hey all,

The flight performance of my Aerobird has been getting worse and worse since my last big crash, which broke the tail and broke the circuit board loose. I replaced the tail with the x-pack tail (same as the orginal one) and got the control board back in the right position (verified by the perfect alignment of the x-pot with the hole in the fuselage.

The plane is EXTREMELY unstable in the air. It needs full tail adjustment and substantial down elevator trim to avoid stalling under full power climbs. It also tries to bank to the right, requiring full right trim to make the plane fly straight. But the worst part is that the plane is EXTRAORDINARILY unstable in the air. I'll be flying along on windless days at half throttle (straight and level, with constant airspeed) and the plane will just suddenly tip 60 degrees off to one side. I have NO idea what is causing this but it is making flying the aerobird extremely frustrating and futile. Before this happened, I could land the plane pretty much wherever I wanted. Now... it's hard as heck not to crash. I can't fly any kind of predictable pattern in the air because I spend all my time fighting the plane just to keep it aloft. It isn't much fun at all.

My first suspicion was that there is something wrong with the control board, so I pulled it out tonight. It looks fine. The servos appear to be undamaged and have full range of travel. My second suspicion was that the tail boom was misaligned (maybe came loose in a crash?) To my eyes, it's perfectly seated. I can't move it at all by pulling it or twisting it, and I'm afraid that if I try any harder, I will break it.

Ideas? Thoughts? I've already purchased a transmitter and will be getting a Dandy sport soon. I've thought about buying a replacement fuselage for the Aerobird, but I hate to do that when I could put the money into a slow stick.

Thanks,
Matt

Your problems sound like the same thing I experencied with my aerobird. The first thing I would say is to make sure that tail boom is not at a angle not only to the side but also pointing down but it sounds like you already checked that. After my first aerobird took one to many crashes its flight characistics were the same as yours and I was forced to buy a new fuselage whitch runs under $50 and it flew fine. Sorry I don't have a better answer.

Cale

Oh well, guess it doesn't matter anymore because I broke one of the servos tonight accidentally.

I might get a new fuse and give the aerobird to my dad. I will be getting a Dandy Sport in the near future, so I guess I'll just have to go without flying for a little while.

Matt

You can still diagnose the problem if you want. Do a range check. Grab a friend, or your dad. One of you takes the fuselage, and the other takes the radio. With the antenna down, walk away from each other. The guy with the radio works the sticks as if he were flying, and the guy with the plane watches it for random twitchiness. As soon as the plane starts to twitch, stop walking. You should be quite a ways away from each other, at least 50 feet.

I suspect that you may have damaged the control board in that crash, and the plane is not responding properly to your commands at range.

If you get a new fuse, search RCU for a thread A tip for all firebird/Aerobird series pilots. Do another search for Aerobird tips or just Aerobird. This is a great plane, after you do some mods and strengthen some of the main areas that could cause problems if you crash like the control board mounts, motor mount, and tail boom. Hope this helps and good luck.

-John

Thanks everyone. I will most likely get a new fuse and give the rebuilt Aerobird to my dad.

I did reinforce the tail boom and motor mount areas with zip ties -- a practice that probably kept them from breaking loose in that crash. I didn't see any tips for reinforcing the control board, though.

Matt

Here are some pics

Just cut a hole on the fuse where there is the hole on the board braces. Drill another hole above that and just zip tie it together. You can put on in on the back too. Only do it on that one side because the components are in the way on the other.

-John

Since the problem started when you changed the tail, I would be suspiceous of the tail not being properly alligned.

Check the manual for stalling and porpoising. The angle of the tail, not the control surfaces but the tail itself, is critical to the plane flying properly.

I would guess the front is down too far, or the back is up too high. The orange screws will have to be turned.

In theory if you loosen the front screw and tighten the back one, it raises the front of the tail and lowers the back. You do that, then try a flight.

Before you do that though, you must get your tail surfaces back to proper allignment - even with the fixed part of the tail.

If the front of the tail won't stay "up" you may need to slip in a think piece of cardboard or something. That is what I had to do.

RTFM

Here are my tips on dealing with a plane that won't fly straight, but I think when you put the new tail on you did not properly trim it.

I have an Aerobird with over 100 flights. I have taught several people to fly
their Aerobirds. Here is the procedure I tell people to follow to get the
plane to fly straight.

If you are having problems because of a bad crash, so let me just offer this
as a starting point.

Unless you have removed the white foam that sits between the battery and the
electronics, ignore Center of Gravity issues for the moment. Do all of your
flight testing with the 6 cell battery. The 7 cell makes it nose heavy and
will change the way it flies. When I am trying to fix a "bird" plane, I use
the 6 cell only.

1) With your transmitter on and all trims centered, and your battery connected
in the plane, but with the motor off, look at the control surfaces on the tail
from the back. Are the movable parts exactly even with the fixed parts? If
not then you are going into a turn the moment you launch assuming the motor is
straight and the tail is straight. More on that later.

Normally, these surfaces have to be perfectly aligned.

2) The boom between the pod an the tail - is it solidly anchored or can you
move it around inside the plane. If it moves, it has broken lose. This must be
fixed. It will either sag causing the nose to go down or it is twisted causing
the plane to turn right or left.

3) Check the tail, especially by the rigid plastic near the boom. Are there
any creases? I had a problem with my Aerobird that caused it to turn to the
right so badly that it crashed because it would go into a spiral. I tried
everything. Turned out there was a crease in the tail that caused the tail to
flex under pressure. On launch, this could take you into the ground.

4) It is possible for the tail to shift from a severe nose crash. There are
trim instructions in the owner's manual. AFTER you have checked the other
items and
fixed or found them to be OK, try trimming the tail for more up or down force.


Other points to be aware of:

When the motor is running, more air moves across the tail so that you get a
faster response for turns. The slower the motor is running, the slower the
plane will respond. When gliding, response can be very soft.

Make sure you are launching into the wind - directly into the wind, or the
plane will be turned by the wind when you launch. Same for landing.

If this doesn't help, I invite you to post photos. These are what I would
want to see:

view from nose to tail - level with the top of the plane - to check alignments
view from tail to nose - same reason

Remove the wing, lay the plane on a table with the tail hanging off the end.
Place a ruler under the body extending to the tail. I want to see if the boom
is straight

surface alignment - make sure your trims are centered, the radio is on and the
battery is plugged in.

view from the tail at tail height - full left command
view from the tail at tail height - full right

If this is an Aerobird:

same - full up
same - full down

Good luck and I hope this helps.

Here's a quick and easy free way to enhance the stability of the Aerobird extreme's V-tail..

Poke or melt a small hole with a paperclip in very top back corners of the v-tail..
then, get thin nylon string or fishing line and tie the two together..tight enough to keep
the two tails at almost 90 degree angle. I crashed mine 3 times..and the v-tail suffered
damage and the 2 fins bent over the small cheap plastic support at the base. This tip keeps the fins
rigid and a lot more stable from forces during flight! TRY IT EVEN IF ITS NOT BROKEN.. MUCH MORE RESPONSIVE =)