Well, just one week after observing Larry’s T-28 crash, I’ve had one of my own.
*Larry did not crash due to pilot error. It looks like his E-flite 40A ESC failed/overheated, and the damage we observed was a logical progession from there.

My crash was due to pilot error. I was practicing some stuff I’ve been doing in Realflight all week, and while I can report immense progress with inverted flight, the rest of my suite had some issues.

I was in command, I had a plan, and I was having a good time.  I was practicing knife-edge flight with the T-28, and Larry was photographing the results.

I had done a few good passes, and in a North->South pass I rolled left.  For some reason I cannot explain, I failed to apply reverse rudder, and sticked the rudder left instead of right.  Not so good.

I entered the manuever at ~40 feet, and if I had come in even 10 ft higher, I would have been OK.  I was grandstanding for Larry’s camera, plain and simple, and the result was predictable.

 Humorous detail:  Nearly everybody who observed this crash saw the canopy leave the aircraft in a way that would resemble a scale ejection.

Trojan Man lives, but only sort of.

I am pleased that the wing survived with minimal damage.  No electronics were damaged in the crash, and I didn’t even break the prop!  

I was really close to pulling this out when I contacted terra firma, so i did not hit at the traditional ‘lawn dart’ angle of attack.

Phew.  I guess I had this coming for a while, considering the experimental nature of the project and the level of comfort I have with the bird.

New, improved T-28 to be developed this week.

- Eli

UPDATE – Well so far I have flown the Pulse, T-28, RV-9, Diamante, and Blade MCX with this radio and love it. Eli showed me the basics of setup and I’ve been able to slowly explore some of the features.  I like the rolling selector for navigation along with the large LCD display. It will be awhile before I use more than 7 channels and require complex mixing, in the meantime I’m just using the basics such as D/R and expo, dual ailerons, and a couple simple mixes. I have not really played with the PC data transfer much although I have been able to backup model definitions. So far so good!

So today is my b-day and yesterday my gift to myself arrived from Todd over at www.toddsmodels.com – a JR X9303 radio + goodies!

Following the JR naming convention this is a (9) channel, (30) model memory, (3) type TX – air / heli and sailplane. This is effectively the XP9303 w/integrated Spektrum 2.4GHz DSM/DSM2 technology. It’s been on the market since approx. late ‘07 if I recall correctly and is regarded as a highly flexible radio. It came bundled with a JR R921 receiver.

I also picked up the USB interface & PC software, you’re able to backup model definitions and theoretically fully configure a model via the GUI then commit it to the radio. Naturally I had to get a neckstrap and the dual TX case from JR as well – the same one Eli uses.

I’ve unpacked it and charged the TX battery overnight, and hope to start playing with it this afternoon. More to come!

Zeke was the one that came up with this, I believe that some of the info came from wattflyer.com. 

Shopping list.  All the power train stuff comes from Hobbycity.

Motor: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=3886

It can never hurt to have a spare shaft: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6488

ESC: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=2165

Battery – Any good 3s 2100 or 2200MAh capable of 20C will do – these are inexpensive and good: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6306

Servos: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=662

Prop (contraversial): http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8097

Four channel reciever of your choice.  I used a JR RS6UL.

Stick of 10mm balsa, and longer motor mount bolts.  I did not measure them (!) but as I recall they were about 2.75″ and there is plenty of room for length back there.  Sorry for not documenting this better.

Depending on if you are upgrading an existing T28 or building one from scratch, you may or may not need airplane parts.   I got mine here.

http://www.redrockethobbies.com/Parkzone_T_28_Trojan_Parts_Listing_s/496.htm

You may want to get 24″ of 3mm CF rod to reinforce the wing.  I did this, Zeke did not and they both fly fine.

Lastly, do not forget to download a copy of the manual, if you do not have it:

http://www.mirafiori.com/~isaac/rc/PKZT28TrojanManualHiResFinal.pdf

On to the build!  In all truth, mounting the motor and modding the cowl is the only real work to this.   Cut the 10mm balsa into four pieces, and drill a small hole in the center of them.  These are going to space out the new motor, but still allow you to use the stock motor mount.  I like this system vs. fabbing up a new mount, because the factory thrust angle is maintained, and you also get the benefit of parkzone’s engineered parts.  In an accident, the motor mount is designed to shear, and hopefuly prevent the motor or the firewall from taking the hit.   You may also consider just cutting the balsa into 2 pieces, and letting them span the mount as you can sort of see in this pic: http://isaac509.smugmug.com/gallery/7306689_7XNyX#469920027_tyLZf

The motor is only going to line up with the factory mount on 2 holes.  We were a little nervous about this, but decided to install it nice and tight, with blue thread locker.  This has not been a problem, but it’s a good idea to check them before each flying session. The more enterprising may want to solve this problem.

 Next, it’s time to employ your Dremel, and relieve the cowl so that the bell of the motor will fit. 

The rest of this stuff is pretty routine.  If you want a more rigid wing, I recommend pulling out the fiberglass spar and reinforcing with CF.  This can be accomplished with flat or round stock, your choice.

Also, it’s important to look at the area where the wing bolts to the fuselage.  My fuse started to get a little loose after 5-6 flights, and I see stock T28’s with some miles on them that seem to need some help there.  I like to use cloth first aid tape and a little bit of 15 minute epoxy like a poor man’s fiberglassing treatment, it seemed to work great.  Lastly, it’s sometimes nice to line the wing saddle with foam tape just to keep the wing cushioned and stable.

The rest of the assembly is routine.  Put a piece of first aid tape over the battery holder area, as the fuse likes to split there.  The ESC will fit right into the stock pocket, and gets a little bit of cooling air there.

We ran this up with the three bladed prop and saw 452watts WOT.   Flight times on a 2200 are about 5-6 minutes with the thing rammed to the firewall the whole time.

Let’s talk about the prop contraversy for a sec.  Just about everyone will tell you that you wil get better efficiency and more speed if you take the three blader off and go with a different prop.  I understand this… and I don’t care.  This airplane looks cool with this prop on, the combination is very rewarding in flight and the sound of the three bladed prop seals the deal for me.  I would love to hear comments and or success stories regarding this. 

So, in summery, you can build a complete ship at a very inexpensive price that will quickly be one of your favorites.  The Parkzone T-28 is a winner due to sweet, forgiving flying characteristics, scale looks, speed and durability.

This modification does not compromise any of the good qualities, but it does make the thing a lot faster.  Some of the guys down at the field have Power 10 motors on the T-28’s and we are flying rings around them. 

Complete gallery here:

http://isaac509.smugmug.com/gallery/7306689_7XNyX#469910197_US9Sq

Enjoy!

- Eli

Off we go.  Many of you are already on the rcflyers mailing list I have been maintaining for some time.

I plan to start writing about my experiences as I go, and if you have the time and the inclination, I encourage you to do the same.  Zeke and I have been discussing this for a long time, and new I’m hoping to bring it to fruition.

Thanks for dropping by!

- Eli