Want an aircraft that can carry two adults and nearly 45kgs of bags for three hours and do aerobatics as well? The 40-year-old design that’s now known as the Super Decathlon from American Champion Aircraft is your best bet. By John Absolon.
When American Champion Aircraft (ACA) designed the Citabria back in 1964, they envisioned an aircraft that was easy to construct, maintain, and most of all fun to fly. Even the name conveyed this because it spelt ‘Airbatic’ backwards.
I can remember seeing the Champion Citabria when looking through the pages of either Janes Book of Aircraft or William Green’s Observers Book of Aircraft when I was learning to fly and then seeing one on the flight line at Archerfield and thinking that would be a fun machine. Then it was known as the Champion Model 7KCAB Citabria.
However, shortly after the introduction of the Citabria, Champion was bought by Bellanca. Bellanca continued to build the range of aircraft previously supplied by Champion, calling them the Bellanca (Champion) Citabria.
The airframe was built in four basic variants. The basic version 7ECA ‘Citabria Aurora’ had an 115hp Lycoming O-235-C1 engine and was first certified in 1964. Developments of the basic aircraft, models 7GCAA Adventure, 7GCBC Scout and 7KCAB were all powered by a 150hp Lycoming.
Bellanca acquired the assets of Champion in September 1970 and used the name Bellanca for both its own products and those of Champion. In October 1970, Bellanca certified the development of the original Model 7KCAB, the Model 8KCAB ‘Decathlon’. Bellanca continued production of these models until 1980 when they too ran into financial problems until eventually the company’s assets were liquidated in 1982.
These designs passed through a number of manufacturers in the 1980s until husband and wife, Jerry and Char Mehlhaff, purchased the rights, designs and certificates to the Bellanca range of the Model 8 Decathlon in 1988. Their marriage didn’t last but their business together did and today they still work side by side running American Champion Aircraft.
For some time, the parts and tooling had been stored in 16 shipping containers in Austin, Texas. They opened a company, American Champion Aircraft in Rochester, a sleepy mid-western town in Wisconsin, to manufacture replacement parts for the original Champion designs around the world. The motto of American Champion Aircraft is “Dedicated to preserving a classic”, and how true that is.
The Super Decathlon was designed principally as an aerobatics competition aircraft. However, these days with the development of more powerful and advanced aerodynamic designs in the same class, the Super Decathlon is used predominantly for aerobatics as well as tailwheel endorsement training.
The original design consisted of a welded chrome-molybdenum steel tube structure covered with fabric with the wings being made of aluminium ribs attached to two wooden spars also covered with fabric. American Champion Aircraft saw there was a requirement for an aircraft that was simple, less costly to build, economical to operate, reliable and easy to fly in today’s General Aviation scene that wasn’t being filled by the current manufacturers and began manufacturing new aircraft in 1990.
The latest incarnation of the Model 8KCAB from American Champion Aircraft, the ‘Super Decathlon’, was born. All aircraft are effectively individually hand-built in their factory in Rochester.
The Super Decathlon was derived from the Model 8KCAB with the major design change being the introduction of a symmetrical aerofoil that improved inverted/negative ‘g’ flight. Additionally, the Super Decathlon incorporated an aluminium spar arrangement compared to the original wooden spars.
Today over 5000 aircraft have been built since the first Citabria took to the air and currently there are around 30 model 8KCAB Decathlons, eight 7GCAA Adventures, 14 7GCBC Scouts and only one of the original 7KCAB Citabrias aircraft on the Australian Civil Register.
A number of these are operated by flying training organisations for exactly the role that they were put back into production for - basic aerobatic and tail wheel endorsement training - and still more are operated by private owners as a recreational aircraft.
The latest variant is now imported into Australia by Steve Maltby’s Australian Champion Aircraft at Archerfield Airport, Queensland. His first aircraft to be imported is equipped with the latest technology available for General Aviation today but still in the classic airframe, albeit with some modern improvements.
VH-SIS has a bright white fuselage with blue and yellow stripes in a combination star burst paint scheme - a most appropriate scheme for an aerobatic aircraft. (Who’s ever seen an aerobatic aircraft that hasn’t had an ‘out there, look at me’ paint scheme?.) One notable Super Decathlon owner overseas is Top Gear’s quirky presenter James May; his is red all over and registered appropriately G-OCOK, his favourite reply in the popular TV motoring show.
In the cockpit
Steve selected a JP Instruments EDM 930 Electronic Engine Data Management System that incorporates rpm, manifold pressure, oil indications, CHT and fuel quantity together on a colour analogue/digital display, an Aspen Avionics EFD1000 Primary Flight Display (PFD) with combination AI and compass, and a Garmin GPS with integrated colour LCD map display to equip SIS.
Attitude Indicator - how reliable will this be in an aerobatic aircraft? Well, actually quite reliable. During our flight test it did topple momentarily after some prolonged vertical manoeuvres, with a red warning message appearing across the display, but after a very short period of straight and level flight it re-erected itself and the attitude information was valid again.
Of course there is the obligatory G meter for aerobatics, ASI and altimeter, these being the only round dial instruments. The ASI, which is calibrated in miles per hour and knots, and altimeter are arranged in the classic ‘T’ arrangement on either side of the centrally mounted PFD. I found the ASI display a little confusing initially as the prominent outside scale is in mph with knots being displayed on the inner smaller diameter scale. I found the MFD tape display more accurate and easier to use as it is calibrated in knots only.
These are of course really only standbys, as their functions are displayed as tape style displays on the upper part of the PFD display on either side of the attitude indicator. However they do serve one other purpose - these are the performance instruments that are visible from the rear seat with a bit of a stretch sideways.
Being used to modern EFIS systems and having previously tested aircraft and systems such as the Collins Proline 21 system in the King Air 200GT, the Garmin 1000 system in the Diamond DA40, and the Perspective (Garmin 1000) of the Cirrus SR22, there was no problem interpreting the Aspen system. But this is the sort of aircraft you fly looking out the big windows. The EFIS is handy when touring the aircraft.
The remainder of the panel layout consists of a transponder and VHF comm stacked with the Garmin GPS on the right hand side. A digital OAT indicator was also located on the left side of the panel above the EDM 930. There was still room on the panel for two other round instruments that use a standard 57 or 80mm cut-out. The possibilities for these spaces could be the use for backup VHF radios like those made by Becker (eg. AR4201) that use minimal panel space and power.
On the lower left part of the instrument panel are the prop rpm and mixture knobs along with the fuel boost pump switch and starter button. The park brake push/pull knob is located under the right side of the panel. The throttle and alternate air source controls are situated on the left side wall above the pitch trim and fuel selector.
The back seat controls consist of a centrally located stick control column, throttle and rudder pedals. These are located on either side of the front seat. Both sets of rudder pedals are equipped with toe brakes.
Located above the left-hand side window is the main switch panel with the master switch, magneto switches and all lighting and electronics master switches. No key required. Although it is above and slightly behind the head of the front seat pilot, it is easily seen and reached with a slight lean rearward and turn to the left.
Importantly, it can be reached by the back seat occupant without the need of duplicating these functions with a separate switch panel, and combine this with the wide mounting of the ASI and altimeter on either side of the PFD, these front seat instruments are visible from the back seat as well, assuming the front seat pilot is not too big across the shoulders.
The cabin also incorporates a ‘sun roof’ - a section of clear canopy over the front seat that improves visibility during aerobatics. This clear panel is handy for visibility in the direction of the turn when the high mounted wing would otherwise obstruct the view. Both seats are equipped with a five-point seat harness.
Weight watcher
Power in the Super Decathlon is provided by a fuel injected Lycoming AEIO-360-H1B, developing 180hp and coupled to an optional MT composite MTV-15-B-C-/C188-34 constant speed propeller. This prop incorporates a wooden spar supporting a composite structure with a titanium leading edge.
As part of the design it will also resist the tendency to overspeed during the varying speed ranges during aerobatics. This is a 15lb weight saving over the standard Hartzell metal prop. There is also an optional three-bladed version of the MT propeller.
Fuel tanks are situated in the leading edges of both wings and hold a capacity of 40 US gallons (151 litres), which easily gives an endurance of three hours plus reserves at economical cruise speeds.
The fuselage is the same proven steel tube construction of early model Decathlons. SIS has been optioned with ACA’s Coastal Corrosion Protection that uses an oil coating on the inside of the tubing to prevent the formation of corrosion from the inside.
The same option includes the use of stainless steel wire in the vertical and horizontal tailplane bracing and control lines. The landing gear on the Super Decathlon is now the standard aluminium faired legs that incorporates the brake lines internally, which has led to a further 13lbs weight saving plus reduced the drag associated with having an external brake line.
The fuselage is constructed as it has been since the beginning, from steel tubing, and the whole structure is covered with modern synthetic Dacron fabric. Being a tailwheel configuration, the tailwheel is steerable through the rudder pedals, but when a tight turn is required a dab of brake coupled with a slight increase in power - making sure you keep that stick back - and the tailwheel comes out of its detent and swivels easily. With a slight aircraft movement forward and with the rudder central, the tailwheel will caster and then relock into its detent.
With a capacity of 100lbs, or 10.4 cu ft, a baggage compartment with a restraining net is located in the rear of the cabin behind the back seat.
The wing construction consists of aluminium ribs attached now to two aluminium spars instead of the original wooden construction. Unlike the other Champion models, the Decathlon has virtually no dihedral, which improves aerobatic manoeuvring.
Situated in the leading edge of each wing root is the 40 US gallons or 151 litres of fuel. Both tanks are coupled together and sealed with a screw cap and are selected either ON or OFF. There are no flaps and the whole wing and control surfaces are covered in synthetic fabric.
All controls are cable operated and the ailerons are balanced with aerodynamic spades that reduce the loads when applying large deflections. The maximum speed for full deflection of flight controls is 93kts IAS. The empennage is made of fairly basic structures, unlike the aerofoil shapes of conventional light aircraft. The tail fin and horizontal tailplane surfaces are essentially flat plate surfaces that are fabric covered.
With the weight savings from the modern avionics, optional prop, new aluminium landing gear and modern electronic instrumentation, this is an aircraft that can go almost anywhere easily, efficiently and safely.
Entry into the Super Decathlon is via a single jettisonable side door on the right side only. The jettison handle is located on the right side of the forward cockpit. The front seat is adjustable but only with a selection of two positions, forward or back, while the rudder pedals are not adjustable. With the seat in the rearmost position, there was ample room for my 189cm frame. The cabin is quite wide and full aileron deflection meant the stick wasn’t impeded by my legs.
The door is secured closed by not only the door catch but by two simple turn latches fore and aft of the door frame. The left side window can also be opened and easily allows ventilation on the ground. Additionally, there are two air vents in the fuselage sides forward of the front seat pilot providing more than adequate air flow through the cabin.
Just visible forward under the instrument panel above and the rudder pedals is the back of the inverted flight fuel tank that holds two minutes of fuel for inverted flight.
Flying the Super Decathlon
My test flight began by meeting Tom Christopher, the CFI of Sunland Aviation at Archerfield. After a walk round the shiny new Super Decathlon looking at the new features of this 30-year-old proven design, I slid into the front seat after adjusting it rearward. The first impression was of a spacious cockpit with ample room for my long legs and a great view over the nose compared to the first tailwheel aerobatic aircraft I had flown, the Winjeel.
Starting the Lycoming was straight forward and no surprises or extra procedures required. While the Decathlon is a little forgiving, the main thing to remember is to keep the stick back - we don’t want any unforeseen nose overs that could damage the prop, let alone be a little embarrassing.
After releasing the park brake, minimal power increase was required to taxi the aircraft forward, a quick check of the brakes to acquaint myself with their feel and their effectiveness and we were on our way. As I had to turn a little over 90º to align with the taxiway, I first applied full rudder and found that with a little application of asymmetric brake and a small power increase, the left turn was no problem.
Taxiing in a straight line took a little getting used to, with minor wanders across the taxiway centreline in the wind. The tailwheel steering felt a little heavier than what I was expecting initially from such a light aircraft but with practice I suspect I would get used to it.
As the run-up bay was full, we proceeded to Archerfield’s runway 28L and planned to do a run up on the taxiway closer to the runway holding point. As we approached the holding point, we found a C172 right behind us intending to do the same thing so we rolled a little past the runway entry point on the parallel taxiway and held to do our run-ups. This would then require a very tight turn of nearly 160º to get back to the holding point. After the runup and completion of the pre-take off actions, this turn was easily accomplished with use of the differential brake and a little power and the turn was completed within the boundaries of the narrow sealed taxiway. Try doing that in a C172! It virtually pivoted on one wheel.
Having not flown a taildragger for close to 30 years, not counting a C180, gliders and self-launching gliders, I could honestly say that I was a little apprehensive considering a crosswind from the left in excess of 10kts. Archerfield’s into wind grass runway was out of service following the recent wet weather.
In the event, it wasn’t a problem. I found the Super Decathlon easy to maintain direction control and although I had to use a little more forward pressure than I expected to raise the tail with nose attitude being a little lower than expected with such great visibility, all went according to plan and a smooth lift-off occurred at 65kts with a smooth transition into the climb at 90kts and 25 in/2600rpm for a cruise climb out to the training area. Best rate climb could have been flown at 75kts but I also wanted not to waste any time in getting out to the area considering the climb rate is quite impressive anyway.
Cruise out to the area was settled at a transit altitude of 3000ft, with the power reduced to 24/2400. This gave an indicated cruise speed of 115kts and without any leaning of the mixture a fuel flow of 12.5US gal/hr. At 5000ft and 55 per cent cruise power, American Champion quotes the fuel flow as 7.6gal/hr and 9.6gal/hr at 75 per cent cruise or 128kts TAS.
After climbing to just under 4000ft, I had a look at the stall characteristics. It’s always good to have a look and feel of the handling of an aircraft close to its minimum limits, especially if it’s a type you haven’t flown before and when you are going to manoeuvre it around closer to its limits anyway. You don’t want any nasty surprises.
The straight and level clean stall was carried out with a little buffet noticeable starting around 52kts IAS and full stall at 45kts IAS. I say clean; because there is no other configuration - remember there aren’t any flaps on this one.
If you held it in the stall, the aircraft tried to drop its nose and unstall itself but with quite a bit of altitude loss. Another stall was carried out and with more aggressive power application and forward stick recovery occurred after minimal height loss.
Bring on the aerobatics
After a couple of clearing wing overs, I tried a few more aerobatic manoeuvres. Loops were commenced at 24 inches and 2500rpm, 120kts IAS and with a smooth but positive application of around 3.5g, checking to hold wings level through the pull, a slight murmur from the stall warning horn over the top, but no buffet, and then with increasing airspeed and g on the recovery back to regain the entry altitude.
Rolls are recommended to be entered at 112kts, snap rolls at 78kts, and hammerheads at 120kts. As we had a couple of lose items in the cockpit that Tom was securing in the back seat, I didn’t explore as much of the negative g regime that I would have liked to. But needless to say, the handling was docile and I can only suspect that sustained inverted flying would be also.
The roll rate, although positive and significantly faster than normal light aircraft, wasn’t quite as fast as I expected from an aircraft with such large ailerons. The control forces were certainly lighter than expected.
I found the rudder forces to be quite light in comparison and I had a few yaw oscillations until I got a feel for it thoroughly. A bit of lazy feet, having flown jet transports with integral yaw dampers, doesn’t help. I experienced a slight problem with the pitch trim slowly inching forward causing a gradual out of trim situation and an increase in back pressure required to hold the nose up. Tom told me that this was caused by the newness of the aircraft and a slight maintenance friction adjustment would fix that.
Throughout the manoeuvres the visibility with a high wing didn’t seem be that big of an issue, even considering that my eyeline was just below the under-surface of the wing. The roll rate, although not as fast as some higher performance two-seat aerobatic aircraft like Extras, was still significantly higher than most other light aircraft, meaning you could easily drop a wing to move the bit of offending airframe out of the way or look through the overhead canopy between the wing roots for a clear view over the wing in the direction of turn or over the side through the great side windows. The only obstruction here is the double struts supporting the wing.
During our manoeuvres, and only after some prolonged vertical exploits did we get any problem from the Aspen EFIS. This was a ‘cross check attitude’ warning across the top of the AI. Because the Aspen PFD ADHRS uses a combination of accelerometers and rate gyros to sense attitude and direction, only a short time of steady wings level flight was required before the warning message was extinguished.
After what seemed like only a short time, we headed back to Archerfield. After checking the ATIS we were cleared to join a left base onto runway 28L. The crosswind had increased slightly from the left and was now up to around 13kts; the maximum demonstrated crosswind limit on the Super Decathlon is 17kts.
Making sure that we were clear of traffic, we were cleared early in the approach to land. Establishing a standard approach path early was my main goal, because without the benefit of increasing drag with flaps, the only alternative was back to basics and a bit of a sideslip if we became too high or fast with the power already at idle. But a normal slope was achieved and with the pitch full fine and little power a normal approach was maintained.
Decreasing the approach speed to achieve 60kts crossing the threshold felt a little slow compared to my usual mount. With a bit of crab on, in the three-point attitude at 60kts we crossed the threshold, selecting idle, a beep from the stall warning, a slight application of right rudder, and the left wing just dropped a little and we were on with a bit of a bump. If I could have just flared a little lower and held it a bit longer into the stall warning horn was the verdict from Tom.
The Super Decathlon is best landed in this way rather than a two-point wheeler landing. Hey, but after nearly 30 years since my last taildragger landing, I felt quite pleased. This just goes to show that the Super Decathlon is quite forgiving and safe to fly.
Versatility in spades
The economics of this aircraft start with the purchase price. Here is an aircraft that starts out valued at US$150,000 and add the few options that Steve has applied to VH-SIS and you get a two-seat aerobatic and touring aircraft for under US$170K. Compare this to other initial entry two-seat aerobatic aircraft, admittedly that are of composite construction and with a little more advanced handling, like the Extra 200L and you will be paying over EURO230,000.
The versatility of this aircraft is its ability to carry two adults and be manoeuvred in basic aerobatics. And yet if you feel the need to travel somewhere for a social fly-in at a remote airfield or that camping weekend up the country, you can load full fuel and 100lbs of bags and it handles the task very well while affording the owner a great view along the way. Not too many other light aircraft can do this.
Specifications
Powerplant: Lycoming AEIO-360-H1B
Horsepower @ rpm: 180hp @ 2700rpm
TBO (Acrobatics): 1400hrs
Wing Span: 32ft
Length: 22.9ft
Height: 7.7ft
Wing area: 169.1sq ft
Wing loading: 10.64lb/sq ft
Power loading (Acrobatics): 10 lbs/hp
Cabin length: 8ft 10in
Cabin width: 2ft 6in
Cabin height: 3ft 11in
Empty weight: 1340lb
Maximum gross weight (Acrobatic Category): 1800lbs
Maximum gross weight (Normal Category): 1950lbs
Useful load (Normal Category): 610lbs
Payload with full fuel: 376lbs
Fuel capacity: 40 US Gal
Baggage capacity: 100lbs 10.4 cu ft
Acrobatic limit loading: +6, -5g
Performance
Maximum inverted level flight: 2mins
Take-off distance ground roll: 495ft
Take-off distance over 50’: 904ft
Maximum crosswind: 17kts
Rate of climb @ SL: 1280fpm
Maximum level speed @ SL: 155mph
Cruise speed @ 75% power: 147mph/3.4 hours
Fuel consumption: 9.5gph @ 5000ft
Cruise speed @ 55% power: 128mph/4.4 hours
Fuel consumption: 7.6gph @ 5000ft
Service ceiling: 15,800ft
Landing distance over 50’: 1051ft
Landing distance, ground roll: 425ft
My thanks to Steve Maltby of Australian Champion Aircraft and Tom Christopher for their assistance with this flight test.
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