Used Aircraft Guide: Tailwheel Maules

Rugged, reasonably priced STOL machines that carry a good load and can go almost anywhere—but watch the ground handling.

Still the only production four-seat or side-by-side, conventional gear airplanes being built in the U.S., Maules have been attracting owners who march to a slightly different beat for over 50 years. In general, the airplanes are easy and forgiving to fly when in the air, yet not so much on the ground—the runway loss of control accident rate is distressingly high. They’re simple to fix, good at going slow but capable of decent cruise speeds, although the published speeds for many in the line are considered humorously optimistic.

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Baggage and cabin access is spectacular with up to four doors. The useful load is okay, but don’t tell that to bush pilots who, according to legend, carry 1500 to 1800 pounds—about double the legal limit—and get away with it most of the time. There have been a number of Maule accidents in which the airplane either did not get off the ground in the runway available, hit obstructions shortly after liftoff or simply refused to climb, so they are not infinitely forgiving of overloading.

A good tailwheel checkout and recurrent training is a must in these short wheelbase airplanes, as our most recent accident sweep showed 58 percent of Maule accidents were groundloops or smacking into something after careening off the runway. On top of that, at least five percent were crashes that came about after getting back in the air on a go around following directional control issues on landing. The accidents were not limited to low-time tailwheel pilots—a Maule must be respected when the wheels are on or near the ground.

Model History
Inventor B.D. Maule started coming up with airplane designs when he was in the Army assigned to a dirigible base. He formed his first airplane company in 1941, but it didn’t last. The family business dates back to the 1950s, when Maule developed the basic design of the current series. A stubby-winged, round-ruddered fabric tailwheel machine with a welded steel tube truss fuselage and a metal spar wing, that bore striking similarity to the Piper Clipper/Pacer. It won an EAA prize at Rockford (before the EAA was at Oshkosh). Maule obtained FAA type certification in 1961, calling the airplane the Bee Dee M-4. It was powered by a 145-HP Continental O-300-A.

Mr. Maule has passed on, but his company hums along after decades spent tweaking the design to create new models that aren’t much different from each other except for their engine options (from that first fixed-pitch Continental to 160-, 180-, 210-, 235- and 260-HP Lycomings, a 210-HP Continental and a 220-HP Franklin) and landing gear choices (oleo struts or heavy-duty spring gear).

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On some models, there also have been constant-speed and fixed-pitch options and a choice between fuel injection or a carburetor. There’s a trigear model and was even a turboprop.

The airplanes evolved from the first M-4 Jetasen into the M-4 Rocket, which had a 210-HP Continental, into the heavier 2300-pound Strata Rocket with a 220-HP Franklin. In 1973, the Lunar Rocket replaced it with a return to the 210-HP Continental. The Astro Rocket, meanwhile, had joined the fleet in 1970 with a 180-HP Franklin. It lasted two years, but 180-HP versions reappeared as one of the M-5 variations in 1979, morphing, in 1985 into both the M-6-180 and MX-7-180, which had the M-7’s longer fuselage and wings and longer ailerons to maintain roll response. A 160-HP Lycoming version was offered from 1995 to 2004.

The M-5 first appeared in 1974 with either a Franklin 220 HP or Continental 210 HP as options. It had a larger tail area and the choice of 63-gallon tanks instead of 40. The demise of Franklin Engine Co. brought Continental’s 235-HP O-540 into the picture in 1977. Starting in 1998, a 260-HP version of the Lycoming O-540 was also offered.

The M-6 appeared in 1981 with structural changes that increased gross weight to 2500 pounds, including wings that were two feet longer than the M-5’s. It offered more flap settings, up from two positions (20 and 40 degrees) to four: 24, 40 and 48 degrees and minus 7 degrees for reduced drag in cruise.

M-5s were made until 1988; the last new M-6 was made in 1991. There was an M-8 briefly (1993). The most recent new model is the 235-HP M-9.

Market Scan
Maules are considered a bargain, even new. A long-of-tooth Cessna 180 can cost more than a newer Maule. The Bluebook puts a 1967 180 at $74,000; a 1977 M-5-235C is priced at about $39,000.

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The Bluebook shows an average retail price for the earliest M-4 of $15,000. Prices range up to $32,000 for a 1973 M-4-220C. The first M-5s run from around $34,000 with the first Lycoming O-540 variant about $39,000. Prices rise for various models through the mid 1980s ranging from just above $50,000 to $60,000 with the O-540 variants the priciest. The first 180-HP models (1979-1981 M-5s) fetch $36,000 to $38,000; later versions run in the $40,000 plus range up to around $46,000 for the last year of the M-5, 1987. A 180-HP, 2010 model M-7 is valued at $145,000.

235-HP M-7s run from $55,000 average retail for the oldest (1982) to $170,000 for a 2010 model, according to the Bluebook.

Performance 
More than once, B.D. Maule took off from inside his company’s hangar in an M-4, breaking ground before getting to the door and transitioning into a steep climb once outside. We are aware that others have repeated the demonstration. His successful marketing message was that this baby gets off the gravel bar and climbs away over the ridgeline like a rocket.

The Maule wing does love to fly and the higher-powered models can leave the ground in somewhere around 250 feet when light (a couple of hundred feet more for the 160- and 180-HP models). At Vx with 20 degrees of flaps, they climb away at a pitch that will make a Cherokee pilot blanch. The combination of high power loading (plenty of horsepower for the weight hauled) and low wing loading (lots of wing area for the weight) do the trick.

Maule has long marketed a 250-300 foot ground roll, and then qualified it by saying it was at reduced weights. We do not know how much the weight has to be to reduced to get that performance. Maules are, in our opinion, STOL airplanes with very good takeoff performance—so we feel the company should be honest in its advertising and give the ground roll at gross weight, rather than some arbitrary, reduced weight.

The company’s odd approach to publishing performance information extends to cruise numbers, especially in its earlier models. Customer comments to us consistently said that they were nowhere near reality. As one owner said, “My M-5-220C couldn’t reach book cruise numbers in a vertical dive with the clutch in.”

Some years back, Aviation Consumer loaded up a Piper Dakota and an M-5-235C to compare them. In cruise, with both engines firewalled, the monocoque-hulled Dakota was 5 MPH faster despite book numbers that showed it to be slower. It also climbed better, again despite book numbers that would have given the steel-tubed Maule the edge.

Readers report leaving the ground in the 235-HP version within 500 feet and climbing out at better than 1000 FPM every time. As for a 180-HP model, the Bluebook’s specs give an M-5 a 900-FPM climb.

In our chart on page 25, we provided published cruise speeds—they should be taken with a large grain of salt. For example, the Franklin-powered M-4-220C has a published cruise speed of 152 knots—reality is closer to 120-125 knots.

Reader reported cruise speeds are all over the place, from 140 to 165 MPH (a lot of Maules have airspeed indicators marked in MPH) for the 235-HP versions. One reason, in part, is that earlier models had highly variable airspeed indications because static ports were affected by small differences in the cowling caused by manufacturing variations and wear. The ports were in the aft part of the cowling, and an ice pick was the tool of choice for adjusting them by creating a lip on one side of the hole or the other to eliminate high or low readings.

Readers say 120 to 125 knots and a 12- to 13-GPH burn at cruise are typical for the 235-HP Maule at 65 percent power. That would be about 10 knots slower than a 182Q burning about the same amount of fuel. A 210-HP M-5 owner said 120 MPH at 60 percent was standard.

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While the two rear doors and removable rear seat option make it easy to throw a lot of big stuff in the back, some well-equipped Maules can be left with a useful load down around 800 pounds. The legend is that the airplane easily outperforms its book load limits. However, takeoff accidents involving failure to break ground on the available runway, impact with obstacles after takeoff and failure to climb after takeoff indicate that the airplanes will not carry everything you can put in the doors.

The low wing loading translates into low stall speeds on the Maule (33 knots for an M-5 with 40 degrees of flaps, 30 knots on an M-6 or M-7 with 48 degrees) and low takeoff and approach speeds.

That means a crosswind will be that much more of a factor than it is in a faster airplane. A slideslip to prevent drift and firm, quick rudder inputs to keep the nose straight are vital to avoiding groundloops. Owners reported that the light wing loading makes the airplanes susceptible to gusts and recommended not trying to land in a crosswind above the demonstrated number.

Another issue is getting enough drag to allow a steep descent over obstacles without building up speed. The post-1981 Maules with the greater range of flap settings address this concern—but watch the flare. As with any airplane approaching the runway steeply, slowly and with a lot of drag, timing will be critical and power will probably be necessary to prevent a pancake or hard landing.

Maules are considered to have lots of control power but not too much stability—a moose-chasing pilot’s dream. Some have been annoyed, however, by a tab on the rudder that automatically deflects to counteract yaw when aileron is applied. The problem is it works well at only one speed, maybe around 90 knots. At slower speeds, you’ll still need to apply rudder to keep turns coordinated.

At higher speeds, too much rudder is applied automatically, which makes for “proverse yaw” or, to put it simply, a skid. “I have owned two Maules so far,” one owner wrote in reply to a chat-room request for comments. “There is not much to complain about. The only thing I would change is to get rid of that tab on the rudder. It is there for those who don’t know how to fly coordinated and is a pain in a crosswind.”

The problem is an apparent reduction in rudder power at slow speeds just when you need rudder power, say for a slipped landing.

Cabin and Comfort
Access to the two front seats is normally awkward, as can be expected in any airplane that sits at a tilt. The Maule’s nose pokes lower in profile than many other tailwheel airplanes, however, so pilots can taxi it without S-turns to see ahead. Access to the rear seats (for up to three people in some models) and the baggage area is exceptional with big doors on each side.

The pilot sits behind the wing, so lateral visibility on turns is poor. Plexiglas doors and a skylight are a factory option that give spectacular visibility down and straight up and received raves from readers. Maules are noisy, especially those with bigger engines. Heating is from a standard exhaust muff, but the back seats in older models, especially, get cold in winter.

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Maintenance 
Maules are considered sturdy and reliable with few maintenance issues. The factory in Georgia is friendly and responsive. It buys and sells used Maules, so parts are readily available. No Maule is an orphan.

Corrosion in wing lift struts prompted a 1995 AD requiring biennial inspections and treatment or replacement, if necessary. Many owners have opted for replacement. Crimping on control cable sleeves, problems with an aileron control pulley, fuel line corrosion and the rudder trim tab control were among the subjects of other ADs.

Cracking paint on the fuselage fabric has been a complaint. So have cracking mufflers. Some tailwheels began breaking after gross weight went to 2500 pounds in 1981, a problem corrected on later models with beefier gear.

Fabric has to be inspected and eventually replaced. It’s not always easy to find a shop that still does it. The factory will, but one owner told us of looking for some alternative to a $27,000 price tag.

Consistent service difficulties and short life spans were reported for the mufflers and exhaust stacks.

Mods, Owner Group
Vortex generators to reduce stall speed even further are a common mod to make Maules even better in the STOL department, available from Micro AeroDynamics, Inc. (www.microaero.com or 800-677-2370). Otherwise, the factory (www.mauleairinc.com or 229-985-2045) offers lots of options, from full swing-up windows, glass doors, window and skylight, three-blade prop for the 235- and 260-HP models, straight and amphibious floats, skis, IFR packages, autopilots and engine analyzers.

The website www.maulepilots.org bills itself as non-profit and unconnected to any commercial operation. A regular in its chat room is “Jeremy the Maule Guru,” former bush pilot and now long-time dealer Jeremy Ainsworth, whose own strictly commercial website is www.maules.com.

Owner Feedback
We bought a new, 2002 M-7-235C with a 235-HP Lycoming O-540 in 2003 and have since put 1600 hours on it. We love it! As they say, there are faster airplanes, there are airplanes that carry more and there are airplanes that cost less, however, nothing matches this well-rounded “Renaissance airplane” in doing so much, so well.

After looking at the type of flying I do, I decided on a tailwheel, high wing with at least two doors. I felt having a tailwheel and low stall speed would minimize forced landing risk. I read all the airplane ownership books I could get my hands on, including the UAG compilation, and narrowed it down to the Pitts S2C, Aviat Husky, American Champion series and the Maule. The Maule had the best combination of features, plus side-by-side seating—important to my wife and me as we are both pilots and share the duties.

I learned that airplanes are like tents—sure, you can put two guys in a two-seat airplane, but you can’t do it with bags and 3.5 hours of gas. In the Maule you can (or three adults and a bit of baggage). Useful load for ours is 761 pounds, so the fifth seat in the back isn’t practical.

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With 235 HP, the airplane is ridiculously overpowered, at least until you get to density altitudes above 10,000 feet. If you are not going to the high country or wanting to climb up high quickly, the 180-HP versions will save you some gas money and give you more useful load.

We’ve taken ours all up and down the East Coast, across the Midwest, to Idaho, Colorado and California and still love every minute.

The observer doors—clear from top to bottom of the door sill on both front doors and the middle door (right side) can be retrofitted. The “picture window” on the left side of the fuselage and the skylight have to be built in at the factory. What a view! The only way to get a better view is to fly open cockpit.

Likes: Fun; inexpensive compared to a twin or retract; manual flaps; solid cross-country and IFR flyer. The tailwheel makes me a better pilot. It has great visibility and is quiet outside with a three-blade prop. Oversize tires mean landing on grass, gravel or up to six inches of snow is a snap. Everybody likes to see a Maule show up. B.D. Maule was a genius, and the family has steadily improved the product over the years without overextending the company.

Gripes: Loud inside (need ANR headsets); easy to overfuel because it’s hard to see the fuel level as the tank nears full; crosswind capability; mufflers and exhaust stacks—have replaced several. The ones repaired by aftermarket shops such as AWI lasted much longer than the ones I got from the factory. When the flap notch bracket got bent, I found that the Maule factory doesn’t keep everything in stock—however, they are still in business and recently they’ve seemed more responsive. At six feet tall, I’m glad I’m not taller when it comes to fitting in the airplane.

Tricks we’ve learned: Maximize hot air flow to the front seats by cracking open the front fresh air cabin vent; pick your fuel stops by price, but if there is more than a 12-knot crosswind, go elsewhere and don’t worry about fuel price. Install an oil quick drain; when the Maule tailwheel starts to shimmy, replace it with an ABI tailwheel.

Andy and Sandy Travnic
Via email

I purchased a Maule MXT-7-180 about two years ago and really like it. It has been difficult to get “good” information regarding maintenance and operation of the aircraft. The Maule factory provides very little information other than basic checklists. The only chart or graph information seems to be the weight and balance data. In the military and other civilian aircraft I’ve flown over the years, there have been charts and graphs for just about everything—not with the Maule.

I found the airplane a bit challenging to land given the large wing surface and its susceptibility to gusts. For night landings, the landing light provides minimal illumination—I replaced it with an LED.

Insurance has been about $1000 per year, and the annual a similar amount prior to additional maintenance that might be required. Fuel flow normally runs about 12-13 GPH at 5000 feet. The fuel quantity indicators are fun to watch during flight as they bounce around in any sort of turbulence.

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Having said all that, the Maule is a great plane. It certainly lives up to its name “Star Rocket,” as it takes off in STOL type distances, 300 feet or so, and having 73 gallons of usable fuel gives a lot of flexibility.

Rich Green
Via email

Maule has an extensive STC list that allows for a seemingly endless combination of fuselages, wings and powerplants, which can be seen on the mauleairinc.com website.

Two shops specialize in maintaining and refurbishing Maule aircraft: Ray Maule (www.mauleflight.com) and former Maule employee, David Wright (www.wrightaircrafttechnology.com). Both do excellent work—you couldn’t ask for more knowledgeable folks.

Oh, and the published cruise speeds for Maules must be a figment of someone’s imagination. My M-5-220C couldn’t reach book cruise numbers straight down with the clutch in.

Gary Miedema
Via email

My wife and I bought “Serenity” in November of 1999. She is a 1985 Maule M5-235 with 360 hours total since new. At the time, I had 250 hours in airplanes (10 hours tailwheel) and 30,000 hours in aviation magazines. I wanted near-182 performance and got it: 120 knots, four people, full fuel (60 gallons with long-range tanks), decent useful load and decent range (13 GPH). We also got that fourth baggage door that will let you easily load folded bikes or a footlocker. And because of that tailwheel, I only paid $55,000.

Insurance was about $2300 the first year until I proved I could land, then back to $1400 per year (but now it has crept up to $2200 in spite of no problems). It really is easy to land. Just stay nervous and pay attention.

I put 300 hours on it the first two years flying for business. I collected a little ice twice climbing out Mountain City, Tennessee, but climb rate remained good. One VFR day, I cruised briefly at 14,500 feet and Serenity was still climbing at 500 FPM when I leveled out. With just me and full fuel, I always get off in 500 feet and climb at 1000 feet per minute. That fat wing loves to fly. The Lycoming O-540 has been great. I replaced one vacuum pump, brakes and master cylinder, engine gap seals and magnetos. Annuals have been very reasonable.

The only problem has been cracking paint on the fabric, which I touch up (not hangared until recently).

ADs have been minimal. I reswagged the cables and sprang for new sealed wing struts rather than endure the expense of the punch test. After hundreds of my landings, the tailwheel came off during a landing on a grass strip. I ordered a new horn, reassembled, rebolted, no more problems.

The cabin is tight but comfortable. I’m six feet and fit fine with a headset, but obesity is not allowed. Both front windows open and ventilation in flight is great. I added the quick-release backseat for rapid loading of bike or camping supplies.

Steve Preas
Conyers, Georgia

I purchased the M-5-235C because I lived in Flagstaff at 7000 feet, where the summer temperatures often produce density altitudes of over 10,000 feet. I was not disappointed with its performance.

The M-5 would comfortably cruise at 125 knots at 2150 RPM and 21 inches and burned 12 GPH. With auxiliary tanks full (63 gallons in my plane), I planned for four hours with one-hour reserve. For a small person (five feet, six inches), comfort is moderate. The seats are a bit too upright for me and more padding was necessary. With a full-sized passenger, elbow room is cramped.

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Visibility is good for a high-wing. The cockpit is noisy. Headsets and intercom are required. For Midwestern winter flying, the heater was only fair.

My plane had the “up gross” kit installed, increasing the gross weight from 2300 to 2500 pounds. My useful load was about 950 pounds. One could fill four seats with 170 pounders (and carry a few charts) if you just filled the main tanks (40 gallons). With full fuel, it is comfortable with two adults, two children and baggage.

The plane lived the first part of its life in Louisiana and consequently had some trouble with corrosion in the cabin area that was repaired. Though the Maule was always hangared at home, it was unfortunately stuck out in a severe hailstorm in Colorado. It cost $10,000 to recover the wings and repaint the tail surfaces and fuselage. The repair was covered by insurance, but it was difficult to find anyone interested in repairing a fabric airplane locally. If I were to do it again, I would return it to the factory. Maules like mine did not have the best paint. While the rest of the plane held up well, the paint did not. Annuals ran anywhere from a low of $1200 to up to $3000 (complying with the one-time strut AD and Hartzell prop AD). Insurance ran $1800 to $2500 for $1 million.

David A Shields
Sioux Falls, SD

In 1999, I bought a Maule 7-235 brand new from the factory. It has been a great airplane and it has taught me more about flying than I have learned from instructors.

The Maule Company certainly is right in all it touts about this being an incredible load-carrying STOL aircraft in tailwheel configuration, but you must first learn how to handle it. I recommend Maule instruction from someone who has 500 hours of bush experience.

This plane can easily lift 1800 pounds of people, fuel and baggage and has a climb rate of 400 FPM on a standard day. The problem is lack of room and the FAA certification only allows 870 pounds. At the FAA max weight on a standard day, you could easily expect 1200 FPM. If you fly this five-seat Maule loaded like a Super Cub—two people and half fuel, expect 2000 FPM from a good pilot on a standard day. I emphasize pilot training is everything on this airplane.

I have the spring gear and it is super heavy duty, as is the tailwheel. This machine is rugged, easy to maintain and repair. Parts are readily available and a lot are marked NAPA auto parts from the factory.

In 2002, I put the Maule on Wip 3000 floats and easily lost 25 knots of cruise. I lost only 100 pounds of certified carrying weight. This plane truly lacks the power as an amphibian. When temperatures reach 95 degrees F, this airplane is useless. The Wip 3000 is just too big for the 235-HP Maule.

Matthew J. Clemente
Troy, New York