The Parkzone BF-109 is an interesting product.  Like most scale warbird replicas, it does not have the most forgiving flight characteristics, and it has a couple of quirks.

I’ve flown mine about ten times now, and I would say that landing smoothly is the biggest challenge.  One tip I can immediately recommend is to pull BACK as soon as the main gear contacts and the wing has stopped flying.  If you don’t pull back, the tail likes to float and the model tips forward onto it’s nose.

I wanted to fly the BF-109 a few times before trying the flap option, and after dumping the 109 on it’s nose a few times this weekend (plus 2 good landings!) I was ready to give it a shot.

The gray tape that covers the aileron servo wires does not survive being peeled back gracefully.  Plan to get some new tape in a similar color before you start.  You will also need a servo Y adapter, a pair of sub micro servos (I used HXT-900) and the pushrods and stuff that came with your kit.  The manual says you need to buy the linkages for flaps, but everything I needed came in the box of my BNF example.

The first brain teaser is how to make the flaps work, considering that the Ar500 is only a 5ch reciever.

On a DX6i, the answer is to plug the Y harness into the ‘gear’ channel on the reciever.   Then go into the flap setup in the DX6i, and set the flaps to 100% down.  Most airplanes need some down elevator to prevent the model from ballooning up when you apply the flaps, but this particular model does not with 1/2″ of flap travel.  I set the correction value to 0, and it stays level, hands-off.

Next, you need to mix the flap channel with the gear channel.  I put this on Mix1, set it to active and 125% down.  Lastly, I reversed the gear channel from the ‘SETUP LIST’, ‘Reverse’ menu.

The mechanical part is pretty easy, too – Place your servos, route your Y harness, and mount the control horns as per page 14 of the manual.  I left my RX powered up so I knew the ailerons were centered as I set it up, and cut the flaps out as per the recommendations in the manual.

With the clevis connected to the third hole on the flaps, and the flap->gear mix set to 125%, I’m getting about 13mm of travel from the flaps when deployed, which is close to the PZ recommendation for half flaps.

My DX6i only has a 2-pos flap switch, and I decided to leave this at the more conservative setting until I have had a chance to fly the model.

Wrapping up the modification, I moved the clevis from the outer hole to the second from the bottom on the ailerons, and overdrove the aileron servos a little bit to get the PZ recommended 3/4″ (19mm) travel out of the ailerons.

This morning, the Winter storm that has been hitting Northern CA took a break, so I rushed out to the field.   I didn’t use the flaps for takeoff, but I flew around with them and did a bunch of approaches.  The flaps do slow the model considerably, and it takes out some of that low-speed wing tipping that everybody is noticing.  Again, there is no elevator correction required at 1/2″  flap travel, I wonder if it will be required when I dial the flaps up to 3/4″. 

It will be a few days before I figure it out, because in the gray skies I got disoriented and had a little mishap.  Thank God Horizon has spare parts in stock…

Please don’t take my numbers as Gospel, and I hope this article helps some folks wrap their head around the custom mix they need to do in the DX6i.

- Eli

**Update 10/26/09 – Crash repairs consisted of a new fuselage and wing

In this iteration, I put the clevis on the inner hole on the flaps and ailerons, and over-drove everything to 125%.  This yields 1″ of flap travel, and just over 1″ of aileron travel.  The aileron roll rate is quite manageable, and there is still no need to dial in an elevator correction with the flaps. 

My 109 on approach with flaps deployed

The flaps slow the model down, but the tip stalling is still there and you still need to land under power.  An experienced pilot friend of mine suggested that I cock each aileron up a few degrees to see if that tames the stalling a little, and I’ll be trying that this week.

Keep the shiny side up,

- Eli

A challenging wind coming from the north this morning caused contributed to a number of ugly crashes, including crashing my own T-28 while doing some inverted hooliganism. As always, I post my RC photos at Flickr.com.

First down was Eli with his Parkzone BF-109G. While making a downwind to crosswind transition, the plane stalled and never quite recovered. Up, down, left, up, down, spin, invert, crash! Thankfully his beautiful bird was mostly spared and came out with a tweaked cowl, broke prop, gear and a few scrapes and scuff. I hadn’t pulled out the camera yet at this point, so click here to see his sleek BF-109G from a few days prior.

My turn! First mistake was that I uttered the dreaded phrase, “Just one more flight.” I tried to cover up the damage but it was too late and the only option was destroy my Parkzone T-28. I had no choice. So up I went up and attempted to pull out from an inverted dive while flying downwind. That didn’t work so well and I didn’t have the airspeed to give me sufficient control authority to pull out while remaining inverted. I hit the ground pretty fast but at a shallow impact angle (this seems to be my preferred angle when crashing BTW!). I saw my tail feathers snap off, but it looked pretty good from where I was standing. Damage was limited to the vertical stabilizer, rudder, cowl, canopy and prop. She will fly again!

Next up, er, down was Chris with his 100 Mph+ nitro sport ship. Dear god, Chris knows how to fly this bird like nobody’s business. However, even the king of A-51 can make a mistakes and today it seemed from the start that he enjoyed flirting to the point of disaster.

He had a few close calls early on:

But later on the fun ended when he tried pulling at, well, I don’t know what he was doing:

I still love flying in the wind you weenies!

- Randy

This Spring, I decided to dress up my T-28 with a lighting kit. I had experimented with the inexpensive Lumifly system you can get at Hobbycity, on other airplanes, but it was very inexpensive and didn’t look very scale.

I tripped on Electrotek RC purely by accident.  I was up in Chico visiting family and was looking for a hobby store.  It turns out that these folks are based in Chico, and specialize in electronics for RC airplanes.  They have a few core products that are designed for gasser ships that need to monitor their reciever packs/etc/etc, and they also have a complete line of lighting kits.

If you are able to do so, I highly recommend you talk to these folks on the phone the first time you order.  Bob was more than happy to talk to me about what I was working on and build me a custom lighting kit with extensions that were just the right length. 

I ordered 2 kits, one for a park flyer (the kit you see on this T-28) that is based on their ‘micro sunbrite’ line, and another kit that I have not used yet, which has much larger LED’s and was designed for a 2M sailplane.

Since I bought all this stuff last Spring, Electrotek has started a seperate line of products designed for foam parkflyers.  I think the new product is cool, but I will note that the stock location on a T-28 for the ramping beacon is at the front of the rudder where I put it, and not at the top of the rudder.

I took a video of my T-28 after installation, apologies for poor quality:

T-28 Navigation lights by Electrotek RC from Eli Caul on Vimeo.

I’m planning to add a set of landing lights in the wings someday, on a reciever controlled switch I got from Turnigy. 

Geeky, scale details like lighting just makes the sport more fun for me

- Eli

I’ve been using the FlycamOne a little bit over the last few weeks.  I’m still not very happy with it, but it does a passable job.

I cannot wait for the next generation of these cameras to become affordable!

Here is a video taken from my Ultra 25 – I did some nice low passes.
I particularly enjoy the touch-and-go at 4:20, after which I roll right into inverted.  I guess I was feeling confident that day!

Area 51 flight, with my favorite airplane. from Eli Caul on Vimeo.

 *Full Screen, full-fat .wmv of the Ultra 25 Video here.

This next video had me nervous - It’s the first time I have tried to mount the camera to my brushless Parkzone Stryker, and this bird has been clocked at 84mph!

Let’s suffice it to say that I was very thorough in mounting the camera, this time around.  Check out the loooow pass at ~1:40, I was literally about 2 feet off the deck.
*I think next time, I need to mount the camera on the underside of the airplane and learn how to land inverted

Flight of the Stryker from Eli Caul on Vimeo.

*Full Screen, full-fat .wmv of the Stryker Video here.

I’m hoping to shoot some new videos at other locations soon – keep an eye on this space.

Happy Flying,

- Eli