So maybe money isn’t a consideration. Youve done we’ll in the market, sold your business or been promoted to senior VP and that ratty old 210 youve been flying just isn’t getting it done.
And neither would a light-light twin of the sort we analyzed in the June issue. The next rung on the step-up ladder is the light non-cabin class twin, airplanes that are a bit more expensive to buy and operate than light-light twins but carry more and eke a few more knots.
These are big airplanes with performance and handling that are less tolerant of an incompetent pilot than the light-light twin. Before considering one, we encourage the prospective owner to keep two ideas in mind:
Never, ever buy one without a pre-purchase inspection that is so complete as to be signed off as an annual. The systems are complex and getting old and you need to know the score before owning the thing.
Second, plan on shelling out the money for semi-annual or annual recurrent training as a part of a commitment to keep your skills at a level commensurate with the challenge of flying twins. If you don’t, any perceived safety advantage will be elusive.
Cessna 336/337
In the early 1960s, Cessna took a bold step, designing a twin that would fit a market niche below the model 310 and which was to be so safe that a pilot could fly it with only a single-engine rating.
Thus was born the Cessna 336 Skymaster with a pair of push-pull Continental engines. The FAA demurred on the no-rating idea, but compromised by creating a multi-engine rating limited to centerline thrust.
The 336 lasted but one year, 1964, before the 337 with retractable landing gear replaced it. The line eventually expanded to include a turbocharged ship and finally a pressurized version with 225 HP at each end. A military variant, the O-2, saw wide use in Vietnam.
The 1965 337 Super Skymaster corrected a number of the problems by retracting the landing gear, changing the wing angle of incidence and bumping up cruise speeds about 15 knots. Useful load in early models leaves much to be desired so they should be thought of as four place airplanes, even though there are six seats.
While the 337 never sold in large numbers, they attracted a devoted following because of their unique capabilities and potential for a high level for safety. The P337 continues to attract the attention of those who want pressurization and good all around performance on a reasonable budget. (The P-model had such teething pains, however, that Cessna brought every one back to the factory for rework.)
Handling and Performance
The 337 will hop off short runways and with its solid low-speed handling, there are no worries about Vmc. The airplane is popular among those who do low-altitude observation for pipe and power line patrol, environmental monitoring and photography. The Skymasters controls are generally we’ll harmonized although the ailerons, while effective, are heavier than youd expect in an airplane of this size. Single-engine handling is dirt simple due to the in-line engine configuration.
Naturally, folks have scratched their heads for years trying to figure out why the accident rates for 337s werent lower than for other twins. All the pilot needs to do when one engine quits is to look at the EGT to tell which engine has exited the mortal coil, feather its propeller and fly on. Raising the landing gear, if down, is not necessary. Yet a number of accidents were reported in which the pilot claimed not to have noticed one engine had failed during takeoff. The FAA mandated a placard for the panel advising pilots to go to full power on the rear engine before bringing the power up on the front, thus assuring the impossible-to-see rear engine is actually running.
Our view, however, is that only the most absolutely incompetent dolt would fail to recognize if one engine were not running during takeoff. While the sound level doesnt change much, acceleration goes from impressive with both running to nearly non-existent with one engine dead. Similarly, the accident pattern-lots of VFR-into-IMC incidents-suggests that, like the Ercoupe, the Skymaster has attracted some pilots who don’t maintain skill levels.
Skymasters are neither fast nor efficient. The normally aspirated models post Twin Comanche speed on 50 more horsepower per engine, although the Skymaster has better handling and better performance on one engine. The T and P models will do 190 to 200 knots in the high teens.
Flight Deck and Cabin
The occupants sit upright in the Skymaster, enjoying good headroom and excellent visibility, better than any conventional twin. The pilot sits ahead of the wing so its easy to see up or down. The fifth and sixth seats are small, uncomfortable for adults and difficult to reach. If theyre occupied, there’s no baggage space at all; any gear must be carried on laps or under the seats.
A baggage pod is available for those who insist on filling the seats but it exacts about a five-knot speed penalty in cruise. With the engines attached to the fuselage, noise and vibration levels are uncomfortably high. Noise attenuating headsets may be a must.
Maintenance
One of the reasons Skymasters are so cheap to buy is because of their maintenance reputation. The airplanes arent easy for a mechanic to work on and the reality is that a Skymaster can be expensive to put right once an owner has let maintenance slip.
The Continental engines have had difficulties with cracking crankcases and oil leaks, particularly in the rear engine. For years, the rear engines were believed to run hot. Owners who installed accurate gauges, usually six-probe CHTs and EGTs, discovered this wasnt true, however.
Windshield leaks are a common complaint. Take some time on a pre-buy to examine the area and look for evidence of water damage. The hydraulic gear is typical Cessna, which is to say complex, with several doors that have to open and shut during the cycle. Plan on aggressively maintaining the entire system.
The Skymaster generates intense opinions and pilots tend not to be lukewarm about the airplane. They either like it or hate it. Its neither efficient nor fast, but the only thing with better inflight visibility is a helicopter or a Partenavia Observer.
Piper PA-34 Series
Having turned one single, the Comanche, into a twin, Piper correctly figured they could do it again with the Cherokee Six/Lance. From the Six line sprung the PA-34 Seneca, with counter-rotating Continentals for power.
The slab-sided machine showed that, in aviation, a box is cheaper to build than an egg. But takes more power to urge through the air. The Seneca debuted at about the same price as the Twin Comanche C/R and both airplanes had similar speed. But the Seneca required a third more power to do so.
From the loading point of view, the box is easier to load and unload than the Twin Comanche and is far more comfortable. The market agreed, for the Seneca rapidly outsold the Twin Comanche during the one year (1972) the two co-existed.
The Seneca is one of those airplanes owners want to dislike but cant. The first several versions of the airplane were, well, ugly. With the softening of curves and a well-designed paint scheme on the Seneca V, Piper has managed to make the flat-sided fuselage look almost sleek.
Visibility is lousy, in our view, with dolphin-like engines completely blocking the pilots view in two directions. Handling is truck-like. There’s no panache to the airplane; yet it does what matters very well: It carries a decent load, at respectable speed and provides a comfortable, easy-to-access cabin for the occupants. Its an airplane clearly designed for passengers, not pilots.
Background
The Seneca I appeared in 1971 for the 1972 model year and, 29 years on, the Seneca V is still in production. The Seneca I had 200 HP normally aspirated Continentals and is best described as a barge. It had heavy, poorly harmonized controls with sluggish response in all axes, poor single-engine performance and less than stellar useful load.
The Seneca I had problems with vibration (some flung spinners in flight) and six airframe ADs in two years. Gross weight was bumped from 4000 to 4200 pounds but a zero fuel weight was introduced. It started at 4000 pounds and moved up as gross weight increased. Poor single-engine performance leads us to recommend avoiding the Seneca I.
The biggest change occurred with the Seneca II, with turbocharging standard. Sea level horsepower was still 200, however, 215 HP was available at 12,000 feet, improving single-engine climb and service ceiling. The Seneca II offered optional fuel of 124 gallons but also introduced another limitation: Maximum landing weight.
Because many pilots of general aviation airplanes don’t know or understand zero fuel and landing weight limitations, these numbers have been widely violated on the Seneca series. A prospective purchaser should not only review the weight and balance of the specific airplane to see if it will fit the desired mission with the weight limitations but also carefully examine the structure for damage from misuse.
Club seating was offered in the Seneca II. Few airplanes left the factory without it once it became an option and we think its far superior to the standard, all-seats-forward seating. Fortunately, the Seneca never succumbed to Pipers mania for T-tails and when the Seneca III debuted in 1981, it had a conventional tail and 220 horsepower per side. Gross, zero-fuel and max landing weights all went up. The Seneca IV had even more subtle changes, primarily aerodynamic refinements to the otherwise gigantic engine nacelles that improved cruise speeds. A different engine variant was introduced in 1997 and the name changed to the Seneca V. Its still in production with a standard price of $540,000.
Handling and Performance
With counter-rotating engines, single engine handling is above average for piston twins. The Seneca I has ponderous, poorly harmonized, generally inadequate controls. The Seneca II was a big improvement. Control gearing and effectiveness was continually improved with each model. However, the airplane will never be considered as pleasant to fly as a Baron or Cessna 310. Cruise speeds range from 160 knots in the Seneca I to 175 knots on the turbocharged models. Gear and flaps speeds are slow, 129 and 107 KIAS respectively, although partial flaps can be deployed at higher speeds. Over the years, these speeds have probably been exceeded so a pre-purchase inspection should include a close check of the gear and flap operating mechanisms.
Flight Deck
Instrument placement is adequate, in keeping with the Cherokee line. We don’t understand why Piper didnt combine tachometer needles in one gauge, as it did with the manifold pressure gauge. Otherwise, controls are reasonably we’ll placed.
For cost purposes, the wastegates for the turbos are fixed. That means the pilot has to manually set the manifold pressure during the takeoff roll, something that takes a little skill and fiddling to avoid overboosting, especially on takeoffs. Owners have advised us that the Merlyn automatic waste gates are worthwhile for reducing the problems associated with fixed waste gates.
The Seneca series has one of the most comfortable cabins of any twin, at least in terms of space if not the seats themselves. The cabin is wide, allowing sprawl room when only four are aboard.
And since the center of gravity range is quite adequate for a six-place airplane, helped by a nose baggage area, C of G is no problem. Cabin access is through one door on the right side for the front seats and through a gigantic set of doors on the aft, left side of the fuselage for the rear occupants and baggage area.
Many owners needing only four seats remove the center row of seats to provide a limo-like cabin with extraordinary room. (Later Senecas offer a beverage center in lieu of one center row seat.)
Maintenance
The Seneca has more than a fair share of ADs, most being one-time items. Some repetitive ones worth noting include 100-hour inspections of the stabilator fittings on original models; 100-hour inspection of the induction airbox on Seneca Is; 25-hour inspections on the exhaust systems of certain models; inspection or replacement of Rajay turbo housings, to name a few.
Overall the Seneca did benefit from Pipers efforts to make it mechanic-friendly. Its easier to work on than most twins and parts prices are reasonable.
While we recognize that not many people take advantage of the capabilities of turbocharged airplanes, those who do run the Seneca at altitude report that the pressurized mags don’t always work correctly. The resulting cross firing can be hard on the engine.
Overall, we would describe the Seneca as workmanlike. The Seneca I has enough shortcomings in handling, repetitive ADs and performance that we cant recommend one. If you are willing to handle the throttles with care and don’t mind stolid handling, a Seneca II through V can be satisfactory and quite affordable.
Piper Aztec
Once Piper stretched, upped the power and tweaked the control system of the Apache to create the Aztec, the designers turned a mediocre machine into a good airplane. An Aztec may be confused with Snoopy in front of his supper dish but it carries a decent load at a reasonable speed, while having respectable handling in all flight regimes.
In 1960, Piper upped the power of the Apache to 250 HP per side, stretched the fuselage slightly, added a stabilator and called it the Aztec. It was the right thing to do, as the Apache wasnt bad and more power made it darn good, even if it was still a steel-tube framework airplane. In 1962, the Aztec B introduced a six-place cabin, nose baggage compartment, optional fuel injection and optional AiResearch turbochargers. The 1964 Model C raised gross weight to 5200 pounds. In 1966, the TBO went from 1200 to 2000 hours, a benefit that could be retrofitted to earlier engines by installation of half-inch exhaust valves. Changes to subsequent models were relatively subtle, although the E had another fuselage stretch and the F introduced a one-piece windshield, optional tip-tanks and a different stabilator.
The airplane has developed a reputation for an ability to carry a sizable load, but the 4400-pound zero-fuel weight must be respected. The bulbous fuselage is roomy; it just doesnt slip easily through the air. Blazing speed isn’t an Aztec attribute.
Handling, Performance
The Aztec belies its ponderous appearance with pleasant handling. Roll is more than adequate and harmonized nicely with the effective rudder. Overall, handling is forgiving with single-engine work not as much of a yawner as the Seminole, but less hard-edged than the Baron or Cessna 310.
The Aztec will handle shorter runways than the 310 or Baron because approach speeds sag as low 73 knots and it leaves the ground on takeoff at 72 knots, with a 68-knot Vmc. A noticeable anomaly to what is normally pleasant handling is the airplanes behavior in turbulence.
Its lousy, in our view, with a roll-yaw coupling thats quite disconcerting to a pilot new to the airplane. The solution is for the pilot to either lock the rudder pedals or apply rudder against the yawing motion. Its easy to time the corrections. Nevertheless, an Aztec in anything more than light turbulence isn’t much fun.
The Aztec is not fast. Figure on 160 to 165 knots for cruise at 65 percent power. Barons and 310s walk away from the Aztec. Gear and flap speeds also leave much to be desired. The gear can come down at 127 knots while full flaps are limited to 106 knots. Quarter flaps can be dropped at 136 knots. There’s substantial pitch change with flap extension. Experienced pilots avoid jolting their passengers by using small flap deflection in lieu of nose-up trim as they decelerate, or drop the flaps while rolling into the turn to base or final. (Careful with the flaps; the indicator system is terrible.)
On landing, hold the wheel full aft and retract the flaps if you want to use the brakes, otherwise the wing stays on the job and the tires slide. Controls are effective and the Aztec will happily handle strong crosswinds, particularly if the pilot is comfortable using differential power.
Flight Deck
Once the standard T-panel emerged in 1968, the Aztec had a nice instrument layout. Before that, it was a hodge-podge. In any case, its big enough to hold most of the toys an owner could want. Still, the practice of using two tachometers instead of one with two needles infuriates owners tight on panel space.
The gear and flaps are hydraulic with most Aztecs having a lone hydraulic pump on the left engine. Later models had an auxiliary pump on the right engine, which moves a prospective airplane into the nice-to-have category. Otherwise, a left engine failure means the gear has to be manually pumped up. There are trim controls for the rudder and elevators, but not the ailerons. Some owners note that if they experience a rolling tendency in the airplane, it just means a gear door hasnt quite closed correctly. There are times the lack of aileron trim is frustrating. The fuselage baggage area cannot be reached in flight, a notable shortcoming.
Maintenance
The hydraulic system needs preventive maintenance. Valves gum up over time. We recommend changing most of the hydraulic system valves, a few at a time, over a 10-year period. For a chubby airplane, the Aztec is not the easiest to work on. It takes one person eight hours to remove and replace both engine cowlings.
Most Aztecs left the factory with aluminum battery cables. Switching to copper is a wise investment, especially in colder climates. One user reported eating five starters because of low voltage to the starter due to line loss in the aluminum cables.
We like the docile handling of this porcine airplane and imagine that low-time multi-engine pilots will get comfortable in it quickly. The lack of speed in cruise will irritate some, but the tradeoff is spacious cabin room.
Baron 55/58 Series
The Baron line evolved from the outstanding Bonanza series via the Travel Air, and split quickly to become two noticeably different airplanes, the 55 and 58. While the handling is similar and many systems are shared, there are differences. Due to space considerations, weve combined the two.
The original Model 55 delivered in 1961 as a four-seat twin with 260 HP Continental IO-470L engines, competing directly with the Cessna 310. In 1962 it became the A55, with a 10-inch longer fuselage and two additional (nearly unusable) seats in the back. In 1964, the nose was lengthened 7 inches, gross weight went to 5000 pounds the B55 Baron was born. The B55 continued in production with evolutionary changes through 1983 when the Model 55 line was discontinued.
Interestingly, the B55 continued in production when the C model was introduced and its own sub line evolved. Entering the market in 1966, the C 55 had 285 HP Continental IO-520-C engines and a fuselage a foot longer than the B. Gross weight was 5300 pounds. The big-engine Barons, as these were known, are discernable from the other 55s by air scoops on the top of the cowlings.
In the 1970 model year, the 55 got a 10-inch stretch, creating the 58. Its double rear doors soon became standard, as did club seating. The design proved so successful that a turbocharged version, the 58T, and pressurized version, 58P, were added in 1976. The turbocharged airplane didnt last long, as buyers opted for the pressurized model.
The 58 appeared with 285 HP engines and has continually been upgraded and changed. The 58P lasted through 1986; the 58 is still being manufactured and is a good seller for Raytheon/Beechcraft.
In later models, the power quadrant was lowered and the throttles were moved to the left of the prop controls while the landing gear handle was swapped with the flap handle to match other general aviation twins.
Naturally, a few experienced Baron pilots had a little difficulty with the transition, but overall it meant less confusion for those flying varying types of airplanes. The control wheels sprouted directly from the panel rather than being on a heavy bar that obscured the view of the lower instrument panel.
Handling, Performance
The 55 series is renowned for good speed, an honest 190 knots at 75 percent power, 180 knots at about 65 percent. It has light controls and in still air, control response is delightful. In turbulence, it can be challenging. An autopilot yaw damper is high on the must-have list.
Single-engine handling is good. However, the airplane does yaw rapidly on engine loss, requiring good technique to keep the thing under control. The Baron is not to be trifled with; recurrent training is a must.