RE: A10 Warthog IMAA legal size from Wowplanes
 

I worked on the assembling the outboard flap panels. The construction is identical to the inboard flap panels. Next I can start on the two outmost aileron panles.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Hope you are all enjoying the build? I need to mention a couple of things at this stage.

I try to design my kits such that the novice builder can easily build them, or the expert builder can easily modify them. For example, this kit is designed with slotted flaps. It can be built for slotted flaps as shown in this build. Or if less complexity is desired desired, simply glue the flaps to the wing, fill with putty and sand the joint, and we have a flapless model. If a more complex Fowler Flap is desired, simply sand the hinge face to a Fowler profile, or add balsa and sand to create a Fowler hinge profile. In other words, this is not the only way to build my kits.

My design objective is to give you a "scale as can be" basic platform, and empower you with the freedom to suit your own skill and imagination. Trust me, you will not hurt my feelings if you don't follow my intructions to the book.

The second point is that a foam model looks kinda rough during the building stage. Be patient and don't get frustrated, when we get to the finish stage, it will look nothing like that.

RE: A10 Warthog IMAA legal size from Wowplanes
 

Continued with the build. I assembled the aileron wing panels next.

A side comment on the use of epoxy glue. Use is as sparingly as possible because it is one of the heaviest part of a foam model. I looked at the A & B part bottles I am using and each weighs 9oz. That's 18 oz (over a lb) of dead weight added if I end up using a whole bottle set. I waste a lot but still that's a lot for a 10 lb AUW plane!!

Now we can join the two outboard panels together with a samll fixed wing section between them as shown in the full sized picture.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Next I joined the two outboard wing panels together with a small fixed wing section in between.
BTW, I am not sure why the size of the pictures has changed. Must be something in the RCU server.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Now that we have the 3 wing panels, it is time to assemble the whole wing.

RE: A10 Warthog IMAA legal size from Wowplanes
 

I worked on assembling the whole wing today.

RE: A10 Warthog IMAA legal size from Wowplanes
 

I cleaned up the TE by temporarily taping all the control surface in their nuetral positions, and sanding in a straight line using a stick sand bar.

Then I worked on the Horner wing tips.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

from the silent lurking majority.......keep it coming!! Very impressive!

RE: A10 Warthog IMAA legal size from Wowplanes
 

I am glad the silent majority is enjoying this.
There is something therapeutic about whittling and sanding a block of balsa with 80 grit paper. I am enjoying it so much.

RE: A10 Warthog IMAA legal size from Wowplanes
 

Progress is a little slow because we have the grand kids visiting us and I get to teach them how to build a model. Man, the questions are driving me nuts.
Anyway, I was able to get the wing mount done today. At this point, we have a fuselage and a wing structure rough finished. I can now move on to the tail.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Looking great. More and more like a hog with every post.
Mike

RE: A10 Warthog IMAA legal size from Wowplanes
 

Mike, yes I can't contain my excitement as it takes shape.

Installation of the blind nut from inside the fuselage can be tricky. The attached picture provides a tip on how it was done.

RE: A10 Warthog IMAA legal size from Wowplanes
 

I started work on the tail, specifically the H. Stab

The H & V stab assembly is designed to be removable for transportation. If you don't want that, it may be glued permanently as is commonly done. The H. stab has a span just under 26" and has two V. Stabs at the tips. The airfoil is symetrical and quite thin, requiring some stiffening. Spars will help flex but not twist, so the only choice is to sheet the tail members with 1/32" balsa to keep it light. The sheeting method I prefer is very simple and effective. Unlike the fuselage we don't have to deal with compound curves so that makes life even simpler. If you prefer other methods of sheeting, by all means.

RE: A10 Warthog IMAA legal size from Wowplanes
 

Rest of the pictures.

RE: A10 Warthog IMAA legal size from Wowplanes
 

Since I am building this one for a removable tail, the tail assembly has to be self contained with servos as part of the assembly. The elevator servo, pushrod & control horn is mounted on the stab and concealed by the rear of the fuselage when the stab is mounted in place.

The H. Stab is eseentially done for now. Next we can work on the two V. Stabs.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Since this is a first build prototype, I expect to find problems, and I did find one so far.

I have overlooked to compensate for the thickness of the balsa added at the wing and tail saddle. That creates a mis-match at both ends of the foam fuselage aft section. The solution is pretty simple and will be fixed in the production version. As for my prototype, I will be working on a temporary fix - add a slice of foam to the tail section and eliminate the mis-match. The plastic end cone will take a mold re-cyle, so we will have to wait on that.

The pictures show the problem and the suggested fix. If you see anything I have missed, please point it out, I will apreciate it.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Will your fillet interfere with the elevator travel??

RE: A10 Warthog IMAA legal size from Wowplanes
 

Excellent point. I will have to keep that in mind as I do the temp fix, which is in progress as we speak.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

I think I have the problem fixed with a temp fix. No one will know except you, me, the lampost, and the rest of the world.
Of course this will be corrected in the production kit and you will not have to do this operation.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

While waiting for the foam putty to dry during the previous operation, I did make some small progress on the V. stabs

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

I continued with prepping the two V. Stabs.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Some more progress.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

I assembled the H & V stab and took care of a couple of details. I think we are done with the tail for now.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Well I changed my mind once again.

I don't like leaving bare balsa covered parts lying around for long in our humid climate here. So I am going all the way with the tail and get it Liquid Sheeted, I know some of you have been patiently waiting to see LS applied, and this will give us all a nice break from the monotony of building one part after another.

First I fill all the voids in the balsa with a filler & build small fillets at the joints. We can use any suitable filler, but I like using a 1:1 mix of Durham's Water Putty and Lightweight Spackle. It's water based, goes on well, and sands even better. Then I apply a coat of ordinary house latex primer to seal the wood and filler and isolate them from the LS, that will go on next. Allow primer to dry overnight in a dry area. No misture must be present in the surface when LS is applied, this is important. A dowel rod threaded through the cable hole make a nice jig.

So here we go.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

I started the LSll after lunch and here is the result. The parts are drying dis-assembled right now. After cure I can re-assemble and post more pictures.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

The tail is long cured and I re-assembled it with tape for picture taking. It will sit for a few of days before I will work on it further. LS will continue to harden for 3 or 4 days, then I will sand & prime it.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

The retracts arrived. The mains were the wrong kind nad have to be exchanged. But the nose was OK so I was able to resume getting the fuselage done.

The A10 has a complicated door system. Two panels behind the struct that come down with it, and a flap door over the wheel. This is way too complicated for my expertise level, so I went for a simpler approah. When I see the more gifted do the doors, I shall be watching and learning.

Here is the CAD drawing for the retract. I can't seen to get the lines darker for some reason. Any help will be appreciated. I am using AutoCad

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

I worked on the gatling gun and the nose cone this afternoon. Here are some pictures of the real gun and the one that I was able to do.

Following is some background on this famous gun.

The General Electric GAU-8/A Avenger is a 30 mm, hydraulically-driven seven-barrel Gatling-type rotary cannon that is mounted on the A-10 Thunderbolt II. It is among the largest, heaviest and most powerful aircraft cannons in the United States military. Designed specifically for the anti-tank role, the Avenger delivers very powerful rounds at a high rate of fire.

The gun is placed slightly off center in the nose of the plane with the front landing gear positioned to the right of the center line.

A very important innovation in the design of the GAU-8/A shells is the use of aluminum alloy cases in place of the traditional steel or brass. This alone adds 30% to ammunition capacity for a given weight. The shells also have plastic driving bands to improve barrel life. They are imposing to examine and handle, measuring 11.4 inches (290 mm) in length and weighing 1.53 pounds (0.69 kg) or more.

The Avenger's rate of fire was originally selectable, 2,100 rounds per minute (rpm) in the low setting, or 4,200 rpm in the high setting. Later this was changed to a fixed rate of 3,900 rpm. In practice, the cannon is limited to one and two-second bursts to avoid overheating and conserve ammunition; barrel life is also a factor, since the USAF has specified a minimum life of at least 20,000 rounds for each set of barrels. There is no technical limitation on the duration the gun may be continuously fired, and a pilot could potentially expend the entire ammunition load in a single burst with no damage or ill effects to the weapons system itself. However, this constant rate of fire would shorten the barrel life considerably and require added barrel inspections and result in shorter intervals between replacement.

The A-10 engines were initially susceptible to flameout when subjected to gases generated in the firing of the gun. When the GAU-8 is being fired, the smoke from the gun can make the engines stop, and this did occur during initial flight testing. Gun exhaust is essentially oxygen-free, and is certainly capable of causing flame-outs of gas turbines. The A-10 engines have a self sustaining combustion section. When the gun is fired the igniters come on to ensure no flame out occurs.

The recoil force of the GAU-8/A[14] is 10,000 pounds-force (45 kN), which is slightly more than the output of one of the A-10's two TF34 engines (9,065 lbf / 40.3 kN each). While this recoil force is significant, in practice cannon fire only slows the aircraft a few miles per hour.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Mo pics

RE: A10 Warthog IMAA legal size from Wowplanes
 

Cockpit & Canopy

The cockpit and parts of the flight-control system are protected by 1,200 lb (540 kg) titanium armor, referred to as a "bathtub". The armor has been tested to withstand strikes from 23 mm cannon fire and some strikes from 57 mm rounds. It is made up of titanium plates with thicknesses from 0.5 to 1.5 inches (13 to 38 mm) determined by a study of likely trajectories and deflection angles. This protection comes at a cost, though; the armor itself weighs almost 6% of the entire aircraft's empty weight. To protect the pilot from the fragmentation likely to be created from impact of a shell, any interior surface of the tub that is directly exposed to the pilot is covered by a multi-layer nylon spall shield. The front windscreen and canopy are resistant to small arms fire.The cockpit has a large bulletproof bubble canopy, which gives good all-round vision.

The cockpit is equipped with a head-up display, which is used for targeting and weapon aiming, a Have-Quick secure radio communications system, inertial navigation and a tactical air navigation (TACAN) system.The pilot is equipped with night-vision goggles and also the infrared imaging display of the Maverick AGM-65.

Lockheed Martin has begun delivery of 21 USAF A-10 aircraft with the embedded global positioning system / inertial navigation system (EGI), which pinpoints the exact location of the aircraft. The aircraft are also to be fitted with BAE Systems terrain profile matching systems (TERPROM).

Proof of the durability of the A-10 was shown when then-Captain Kim Campbell, USAF, flying a ground support mission over Baghdad during the 2003 invasion of Iraq on 7 April, suffered extensive flak damage to her A-10. Enemy fire damaged one of the A-10's engines and crippled its hydraulic system, forcing the back-up mechanical system to operate the aircraft's stabilizer and flight controls. Despite this, Campbell managed to fly it for an hour and landed it safely at the air base in manual reversion mode.

That's the real McCoy. As for the kit, we have several options.

1. A cockpit interior option will be available as shown in the picture below. Requires assembly and painting. The pilot is built in so we don't need a separate pilot figure in this case. The pilot's head is separate and a small servo can be hidden in his chest to make his head turn. If you want to go all the way, the rear half can be cut and built to open with another small servo.

2. The kit comes with a plain canopy and a simpler cockpit can be built with just framing and a off-the-shelf pilot figure.

3. The canopy and cockpit is right on top of the battery hatch cover. That means we can have all of the above by building several hatches.

As for this build I will go with option 2 to save time. I shall do a separate build for the cockpit interior because I need a manual for that too. But that would be after the maiden. Maybe I will do a third cockpit with just a camera in there for VR goggle flying.

I have searched unsuccesfully, far and wide, for a nice modern jet pilot figure about 1/10th scale. If you know of a source, please let me know asap. I will be needing it soon.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Whoops forgot the pics.

RE: A10 Warthog IMAA legal size from Wowplanes
 

Do you have a target date for the release?
Mike

RE: A10 Warthog IMAA legal size from Wowplanes
 

Mike
I am shooting for Aug 1 + or - a few days.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

Thanks can't wait for the flight test reports.
Mike

RE: A10 Warthog IMAA legal size from Wowplanes
 

Next we do the canopy. I am going with the basic plain Jane version for now. Will replace with the cockpit interior version after the maiden.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

While waiting for the battery hatch cover/ canopy floor to cure before painting, I started on building the last remaining assembly - the Powerplant. It is getting late so I will finish it tomorrow.

There are several reasons for the unusual location of the A-10's General Electric TF34-GE-100 turbofan engines. First, the A-10 was expected to fly from forward air bases, often with semi-prepared substandard runways that presented a high risk of foreign object damage to the engines. The height of the engines lowers the chance that sand or stones will enter the inlet. This also allows engines to remain running, allowing for shorter servicing and rearming turn-around times by ground crew. Servicing and rearming are further helped by having wings closer to the ground than would be possible if the engines were wing-mounted. The position also reduces the infrared signature further, which is already low due to the engines' 6:1 bypass ratio. Because of their high position, the engines are angled upward nine degrees to bring the combined thrust line closer to the aerodynamic center of the aircraft. This avoids trimming measures to counteract a nose-down pitching moment if the engines were parallel to the fuselage. The heavy engines require strong supports, so their pylons are connected to the airframe by four bolts.

The A-10's fuel system components are protected in multiple ways. All four fuel tanks are near the center of the aircraft, reducing the likelihood that they will be hit or separated from the engines. The tanks are separate from the fuselage; thus, projectiles would need to penetrate the skin before reaching the tank. The refueling system is purged after use so that all fuel in the aircraft is protected. All fuel transfer lines self-seal if they are compromised. Most of the fuel system components are inside the tanks so that if a leak were to occur from the component the fuel would not be lost. If a tank does get damaged, check valves ensure that fuel does not flow into the compromised tank. Most importantly, reticulated polyurethane foam lines both the inner and outer sides of the fuel tanks, retaining debris and restricting fuel spillage in the event of damage. The other source of possible combustion, the engines, are shielded from the fuel system and the rest of the airframe by firewalls and fire extinguishing equipment. Even in the event of all four main tanks being holed and all contents lost, sufficient fuel is carried in two self-sealing sump tanks to allow flight for 230 miles (370 km).

RE: A10 Warthog IMAA legal size from Wowplanes
 

Resumed work on the Power Plant. The engine pods are designed to have a hinged service hatch just like the real A10 for access to the motors and fans.

Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

The battery hatch cover had cured, so I went back & finished the canopy.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

I took a day off yesterday and returned to finishing he power plant this afternoon. While the glue is curing, I thought I should post these pictures.
The assembly of the power plant requires some patience but is not at all complex.
Fahim

RE: A10 Warthog IMAA legal size from Wowplanes
 

More pictures. The next job is to mount the power plant onto the fuselage.