Air Tractor AT502b 1/3 scale
 

A little bit background... The last few years I went to Sweden with my friend Roger (see http://rc-cropduster.com) for holiday. We then stay on a small airstrip in a little cabin of our friend Nils Bertil Peterson. (Yes, I know that for US being on a small deserted airstrip is not that special, but trust me, in a crowded Europe, and especially in overcrowded Netherlands, it's absolute rare to have this option...[8D] )

Last year, we got to talk (discuss, daydream, you get my drift...) about Air Tractor building. After all, to my knowledge to date there are only the kits from Duane Habets in Montana and Hollis Calvert in Mississippi and the small electric from David Blum. Well, a result of those talks was a project that started last September, and was kept in secrecy from Roger and me. And even a surprize visit about 6 weeks ago did not reveil anything (mind you, it's 700 miles north, that's a long drive for someone in a country of only 230 miles long...).

But during our vacation early June, the official rollout and presentation took place (yes, with music, fireworks, slowly opening hangar doors, the works...;) ) And here the result of the project to date. Many thing need to be fixed and finished, but the intention is clear. :D

Type: Air Tractor AT502b
Scale: 1/3
Span: 5.28 m (208" )
Weight: 28 Kg (62 Lbs)
MTOW: 45 Kg (99 Lbs)
Engine: gasoline boxer 160 cc (9.76 ci) 18 HP
Prop: 32x10 wood 2 blade

It is build up from bleu foam and plywood, covered with brown paper and glue. At this moment still a 3 channel (yep, no ailerons :eek: ) but that will be fixed. If you like I can load more detail construction photo's. First flight is scheduled later this year, hopefully in August/September.
A fully working spraysystem is being planned also.

RE: Air Tractor AT502b 1/3 scale
 

CRIKEY! That thing is huge! How many acres an hour can it spray? :) Duane is going to have a heart attack when he sees that, Ben!

RE: Air Tractor AT502b 1/3 scale
 

OMG!! [X(]:D[sm=thumbup.gif]

Details from build 1
 

So, lets start to tell some more of the buiolding process. As I mentioned, it was kept in secrecy. Therefor Nils had a complete complete communication and parameter security system. If you are to belief him, including infrared, satelite, and most likey a direct uplink with NSA, KGB, and what have you... :D

But, serious, here some of the 3D views they used to scribble down the sizes.

The main wing spar, with build in dihedral.

Nils cutting of the wing tip with the home build foam cutter

RE: Details from build 2
 

The wing is cut from 10 cm (4" ) blue foam. This is the thickest that was easy obtainable, and would dictate the thickness of the wing. As you can see, the part are hollow.

The leading edges are glued to the main spar.

The rear parts of the wing is being glued to the main spar. The plywood main spar is a tilted U shape, so the leading edge is into the spar, the rear is agianst the spar.

Nils showing a finished wing.

Details from build 3
 

Here Nils is finishing the traing edge, cutting a nice edge.

Also the dihedral is being cut, so it will fit the fusalage properly.

The main spar is finished with heavy mat, normally used for tile wall corners.

The wing (and the rest of the plane) is being covered with brown paper. Yes, this is your house and garden variety of the brown packing paper you use to post packages... It is glued on with a standard white glue. After drying it gives a fairly strong finish. It might not beat glass and epoxy, it dents easier, but it is still light and especially cheap.

Details from build 4
 

Finishing the wing, covering with white glue and packing paper. One of the objectives (next to the shear size [8D] ) was to build from cheap, at the DIY shop obtainable materials as much as posible. Nils, and especially his friend Micke have years of experience building planes with these materials. It is fast, simple, and fairly durable, but definately a working concept, even on bigger scale.

The first batch of formers for the fusalage.

First construction of the main box, basicly the hopper area , where the wing and gear will be attached.

Hopper Area taking form. The thick plywood blocks will support the gear.

Details from build 5
 

The box has a double bottom, basicly an extra box, for additional strength. Also additional plywood to support the gear to the box construction.

The second bottom is in place in the box

The box (hopper area) takes shape. The other formers are kept in place by round wood. Again, this round wood and plywood is straight from the DIY.

Fusalage construction.

RE: Air Tractor AT502b 1/3 scale
 

That is really cool! Packing paper, that cracks me up

Details from build 6
 

Hmmm, a little blending in the background, but the fusalage is getting it's distintive shape.

Fuselage seen from the rear. Clearly visible the round wood to support the formers.

Detail of the nose (engine) section. The heavy plywood firewall is in place. The nose section can be removed completely from the hopper area, since another requirement of this plane is that it can be transport in a standard issued Mitsubishi Galant hatchback. That means that the fuselage will be in 3 parts, motor, mid section (hopper/cockpit and rear fuselage) and the tail section. These sections are bolted together.

Fuselage is really getting shape...

Details from build 7
 

The engine comartment bolted to the hopper box.

The fuselage is covered with 2 cm (5/8" ) foam. This was not present, so thicker plates were cut to thickness.

(bottom two) Fuselage is being covered.

Details from build 8
 

The hopper tank is cut in shape. This is later converted to a large cover that can be removed to acces the hopper area (not only a large real hopper tank is planned, also the bolds for the nose/engine comartment are here.

The cover is build up from loose parts, which when gleud will be a large cover.

The top rear of the fuselage is being cut. this is massive foam.

Setup of blocks for the canopy turtle deck.

Details from build 9
 

Start of the canopy building. This was a difficult part. It has been build twice. The first try did not give the desired result, the shape was to skinny. It took days of work, that then was discarded. The second try was very succesfull, but it is truly a difficult shape to hit. And a wrong cockpit on a plane like this (like the upper deck of a Boeing 747) can easily ruin the whole plane.

Canopy in rough shape. Not sure if this picture is from first or second cockpit.

Building the window frame.

The cockpit in the rough...

Details from build 10
 

Nils grinding and shaping away on the cockpit. Doesn't he look serious? (rare moment....[8D] )

Detailing the cockpit roof. As a true sculpter, the whole plane is in a block of foam, you just grind of the parts that don't fit the plane...:D

Detail of the dashboard. Most likely the rear of a scale hopper tank and pedals will be build here.

Extra plywood to support the firewall and the start of the top of the motor compartment. This is buyild same as the hopper cover, and can be fully taken of to acces the rear o f th engine, the fuel tank and throtle servo and the bolds that will attch the complete nose to the center fuselage.

Details from build 11
 

Building up the nose cover.

Cutting the top of the nose cover.

Also the bottom of the nose section is covered with foam, cut to shape.

The final nose section. The top was later cut to a seperate, removable cover.

Details from build 12
 

The elevator are strengthened and connected with carbon rods. The elevators are made removable for the tail section to be transportable.

Cutting of the tail.

The finished tail, rudder not yet cut out.

The tail is being assembled. The rudder is cut out. the rudder has thin plywood strenthening. Also the elevators are being mounted.
Also notice that the fuselagetail section is build up in plywood. This is also bolted to the main fuselage, for transport reasons. Note the detailed opening for the tailwheel frame.

and now...
 

Now, of course the project needs finishing. These foto's are the build until June 5, 2004. Keep in mind that the original idea started on mid September 2003. Then the team of three, Nils, Micke and Lasse spend many hours building, after at first almost even more hours that Nils and Micke spend on the phone discussing the 'how' of the project.
I think it is an impressive work so far, done in record speed. I do know that the week prior to the roll out on Saturday June 5th, Nils did not really sleep much. Having a dayjob (night shift actually, that week...[8D]) and also claiming to have lost a productive weekend when I did my surprise investigating visit about 4 weeks earlier (and going home knowing exactly the same as when I arrived, really nothing...:eek:), meant that a lot needed done the first week of June. The tail cutting started on the Wednesday that week, and the plane was painted yellow the morning of the rollout, when Nils came out of nightshift at 06.00. Talk about dedication...

During the week we had many talks on what should be build in, and how to build planes with all these foam options. Next to the flying, a very pleasnt way to spend a holiday.

Plan is tyo get the plane finished for flight in the next few month. That means that it should fly sometime in August/September this year.

RE: Air Tractor AT502b 1/3 scale
 

That's awesome! Congratulations on your efforts! Be sure to let us know how it flies...

RE: Air Tractor AT502b 1/3 scale
 

Way to go guys!! Great looking project and one I can really relate to;)

Will be watching for more pics on the build..............:):D:)

Later
Gregg

RE: Air Tractor AT502b 1/3 scale
 

Awesome airplane, very nice build threat.
I hope she'll fly ok. Make sure you keep sending pics.;)

Good luck.

RE: Air Tractor AT502b 1/3 scale
 

No new pics at this moment, but the guys at Hornlanda have started work on the plane again. Scheduled maiden flight in May/June, when we get up there again.
Two rumors from the (at this moment cold) north, they are working on another highly secret project, ready for rollout in May/June, and they might do some experimenting with foam cut electric Air Tractors. More to come...[8D]

RE: Air Tractor AT502b 1/3 scale
 

If it ever makes it to kit form, I WANT ONE! I've got a few hours in the AT-402, and a bunch of hours in the 600 Ag Cat, so this one really interests me!:D

RE: Air Tractor AT502b 1/3 scale
 

that is sweet!

RE: Air Tractor AT502b 1/3 scale
 

oopoooos

RE: Air Tractor AT502b 1/3 scale
 

Duane Habets kits the AT-502 92"