Maule 6

Maule 6The Maule M-5 Lunar Rocket is well known for its STOL capabilities. Now Belford D. Maule has answered operators’ requests for “more wing” by certificating the M-6 Super Rocket. With two feet four inches added to the wingspan, the M-6 gives even more impressive performance (stall speed lowered 10.5 knots, for instance), claims Maule. And the M-6 offers more unusual features in an already unusual design.

The aircraft is strangely nice looking, neither a show-stopper nor an ugly duckling, though it comes closer to the latter. The nose seems to thin for the boxy rear fuselage and the large tail surface. The gear struts also are wide and utilitarian looking. But it is performance, not looks, that counts in the backwoods.

The 235-hp version is the star performer, and most of the aircraft leave the factory with the large engine, said Dan Spader Sr., aircraft sales manager and chief test pilot. That is the model I flew for this report.

With its low power and wing loadings (9.79 lb/hp and 13.2 lb/sq ft) and light weight (1,400 pounds empty; 2,300 maximum takeoff and landing), the aircraft can leap off from incredibly short fields. The claimed length for the M-6, taking off or landing over a 50-foot obstacle, is 500 feet.

The aircraft is constructed of one-piece welded 4130 steel tubing, covered with Razorback fiberglass coated with butyrate. The wings are all metal with fiberglass tips. Flaps and ailerons are also metal.

The wing on the M-6 has been lengthened from 30 feet 10 inches to 33 feet two inches. Each flap in now 10 feet long, and the ailerons have been moved farther outboard. The flaps have three down positions: 20, 40, and 45 degrees. A bungee system automatically brings the flaps down to 50 degrees as speed slows to 48 knots on approach. If you do not want full flaps, you can leave the handle at 40 degrees. If you need to go around, applying power brings the flaps up to the 45-degree position (you will have to take over with the rest).

Spader said that the flaps also could be used as speed brakes for a fast descent. He noted that there are no restrictions against slipping with full flaps either.

The added lift from the longer wing naturally produced a disadvantage – loss of cruise speed. Maule ingeniously solved this problem by adding negative flap. Lower the flap handle beyond the neutral position, and you get seven degrees flaps up. The flaps tilt up at only a slight angle; but when the negative position is cranked in the air, the airspeed indicator gains a not-so-slight five knots (varies with altitude).

The use of negative flap was so unusual, the FAA did not know what to make of it; but Maule tested it under many different loads, and the configuration proved structurally sound. “There were no adverse effects,” said Spader, “and there are no restrictions on the use of negative flaps. You can even land with negative flaps.”

For my introduction to the M-6, Spader and I taxied the bright red and white aircraft out of the line of Maules ready for delivery and trundled down the ramp. A few hundred feet down the ramp, Spader turned the aircraft back toward the rows of aircraft for our runup. He pulled back one notch of flaps and shoved the throttle forward. Before I could yell, “Watch out for your inventory,” we were off the ramp. The tailwheel hit the pavement and we bounced into the air, climbing out well above the rows of Maules at 61 knots, best angle of climb

Spader said the takeoff distance has been measured at 45 feet; landing roll, 100. (Don’t count on performance like this, of course, with a pilot of average skills and any sort of load.) With the certification of the M-6, Maule produced a full set of performance charts, something it had never had before.

When I made my first takeoff – on Spence’s Runway 32, not the ramp – the little Maule was off practically before I had shoved the throttle all the way in. If you want real short-field performance, hold the brakes as you push the throttle in, with one notch of flaps cranked in already, and pull in 40 degrees as you rotate. The M-6 pops right off the runway from practically a dead stop.

Landings were equally impressive. The M-6 floated in so slowly on final (at 44 to 48 knots, the flaps extending the full 50 degrees as we glided down) that I could have counted all the rows of cabbage stretched out in the field below us. “Drives tower operators wild,” said Spader, as we hung over the threshold. Landings were surprisingly easy, despite my being rusty in tailwheel touchdowns.

Climbing out to altitude was not as dramatic as the landings and takeoffs, but the M-6 managed to maintain a healthy 1,000 fpm climb through 9,000 feet. We were lightly loaded and the day was not too warm – the outside air temperature was 40ºF by the time we reached 11,000 feet. Leveling off for cruise at 11,000 the aircraft was indicating 117 knots. 65% power gave us 112 knots indicated; and 60% power, 104 knots. Small tires and speed fairings can add three to five knots to cruise speed, compared with the performance with large tires, said one Maule owner.

On the opposite end of the scale, power off, we stalled well below the 35-knot indication. With power on, there was a definite buffet on the rudder pedals, which Spader said is caused by the slipstream over the elevator, as the aircraft stalls at just less than 45 knots. Control response was good and the stall was gentle.

Maules truly are specialized aircraft, and they obviously appeal to those who have need of a utilitarian airplane. With the M-6 you can take off or the back country and land on a short strip. You can load up through those cavernous doors with bales of hay, a full day’s catch or whatever 500 pound load needs hauling out and take off from an appropriately small strip. Or, if you want, you can use it simply to amaze the folks at the airport when you bounce it off the tailwheel before you roll past the first runway light.

See the original article:
Maule M-6

Mary F. Silitch, AOPA Pilot, July 1982

The aircraft is a four-place, high-wing, single-engine airplane, equipped with conventional landing gear.
This airplane is certificated in the normal category. See the airplane’s P.O.H. for approved maneuvers. The airplane is approved for day and night VFR/IFR operations when properly equipped and certificated.

The airplane is powered by a horizontally opposed, four cylinder, direct drive, normally aspirated, air cooled, carburetor equipped engine. The engine is a Lycoming Model O-360-C1F and is rated at 180 horsepower.

Two 21.5 gallon main fuel tanks, mounted in the inboard end of the wings, have front and rear outlets. The fuel lines running from these tanks terminate at the fuel selector valve on the left side kick panel. The fuel selector valve has four positions: LEFT, RIGHT, BOTH, and OFF. The fuel then runs through the firewall to the fuel gascolator. Fuel runs from the gascolator to the electric fuel boost pump, to the engine driven fuel pump, and then to the carburetor. If installed, two auxiliary wing tip fuel tanks, 11.5 gallon capacity, are mounted from the outboard wing bay. They are fuel transfer tanks and simply supply fuel to the main tank through a small vibrator pump.

The electrical system is a 14 volt, 50 amp, direct current, single wire circuit using the airplane structure as a ground return to the battery. The lead plate type storage battery is rated at 12 volts.

  Maule M-6-180
Super Rocket
Maule M-6-235
Super Rocket
Engine:    
Model Lyc. O-360-C1F Lyc. O-540-J1A5D or
Lyc. IO-540-W1A5
No. Cylinders 4 6
Displacement 361 cu. in. 541.5 cu. in.
HP 180 235
Carbureted Or Fuel Injected Carbureted Carbureted or Fuel Injected
Fixed Pitch/ Constant Speed Propeller Constant Speed Constant Speed
     
Fuel:    
Fuel Capacity Standard Tanks: 43 gallons
Auxiliary Tanks: 33 gallons
Standard Tanks: 43 gallons
Auxiliary Tanks: 26, 30 or 42 gallons
Min. Octane Fuel 100 100
Avg. Fuel Burn at 75% power in standard conditions per hour Unknown Unknown
     
Weights and Capacities:    
Takeoff/Landing Weight Normal Category 2,500 lbs. 2,500 lbs.
Takeoff/Landing Weight Utility Category  N/A N/A
Standard Empty Weight 1,385 lbs. 1,450 lbs.
Max. Useful Load Normal Category 1,115 lbs. 1,050 lbs.
Max. Useful Load Utility Category N/A N/A
Baggage Capacity 250 lbs. 250 lbs.
Oil Capacity 8 quarts O-540: 12 quarts
IO-540: 8 quarts
     
Performance    
Do Not Exceed Speed 156 Knots 156 Knots
Max. Structural Cruising Speed 126 Knots 126 Knots
Stall Speed Clean Unknown Unknown
Stall Speed Landing Configuration Unknown Unknown
Climb Best Rate Unknown 1250 FPM
Wing Loading 15.1 lbs./sq. ft. 15.1 lbs./sq. ft.
Power Loading 13.9 lbs./hp 10.6 lbs./hp
Service Ceiling Unknown Unknown