Light-Light Twins Compared

From a surprisingly large field, the Cougar, Seminole and Duchess are top picks.

After one too many nights in the clag over the mountains or the Great Lakes in a single, youve finally decided its time for a twin.

Yes, operating costs will be more than twice that of a single of comparable speed and your new twin may not even haul the same load as that single.

However, you want a fighting chance when an engine quits at night, over water, with instrument weather below you. Sounds reasonable to us. But which twin to buy?

Three assumptions here: A $900,000 new Baron isn’t in your future; youre shopping used. Second, youre not after a cabin class cruiser to start but a light-light twin having fewer than 200 horsepower per side. we’ll treat larger twins and turbines in a future article.

Finally, we assume you know this but we’ll say it anyway: Have a thorough pre-purchase inspection done by your mechanic, not someone suggested by the seller. Weve seen too many buyers enticed into a good deal on a twin only to find it needed repairs beyond the value of the airplane.

These days, twin prices are so depressed that on some models, overhauling the engines will exceed half the hull value. Better to know that going in than find it out later. And when you finance the twin, set aside some money-25 percent of purchase price is a good figure-for repairs you’ll need (not improvements) during the first year of operation.

Because of space limitations, weve divided available twins along three lines; light-light, medium and cabin class. If the model youre interested in doesnt appear here, stay tuned. we’ll get to it later.

Piper Apache
The first of the light-light twins to reach the market, the Apache (PA-23-150) is known today as a good multi-engine trainer or time-builder. This twin deals with short runways well, has acceptable handling but abysmal single-engine performance. It also has a true Vmc that must be respected as more than one has rolled over and killed its occupants when the pilot let it get too slow on one engine.

The Apache emerged after Piper bought Stinson and used drawings acquired in the deal to build the Twin Stinson. That design-fixed-gear with a pair of 125 HP engines was, charitably, a flying argument for retroactive abortion. Piper rightly figured it could do better. It kept only the steel tube fuselage, covered the beast in aluminum, folded the gear and boosted the power to 150 HP per side.

The result was a chubby little airplane that could carry four in reasonable comfort, if slowly. When it appeared in 1954, 135 knots wasnt bad considering that the only other twins were the Cessna 310 that went much faster with 90 more HP per side and the cabin-class Aero Commander 520.

In 1957, the engines got an additional 10 horsepower (PA-23-160), which bumped gross weight 300 pounds but actually reduced single-engine rate of climb to a published 180 FPM, which we still consider optimistic. The Aztec debuted in 1960 and shredded Apache sales but the PA-23 survived through 1961.

Handling and Performance
The Apache shares the same airfoil with the J-3 Cub. Amazingly, an Apache can depart over a 50-foot obstacle in 1100 feet if everything is done precisely. However, Vx in that maneuver is so slow that if an engine fails, the airplane will roll, so you’ll either hit the obstacle upright or the ground inverted. A more realistic distance for obstruction clearance is 1500 feet, which still isn’t bad. The Apache is one of the few twins we would base at an airport having only 3000 feet of runway. Piper claimed the Apache would cruise at 150 to 160 knots; an absolute fantasy. At 65 to 70 percent power, it will bumble along at around 135 knots, burning about 15 GPH.

Single-engine performance may simply not exist on an Apache. Climb is a function of power available beyond that needed for level flight. Supposedly, the Apache has a single-engine service ceiling of 5300 feet on a standard day and will climb at 240 FPM at sea level (compared to the 180 HP Seminole with about the same useful load and 3800 feet and 212 FPM on one engine). The Apache has a Vmc that must be respected, unlike the more modern counter-rotating propeller twins. As a result, we consider it a superior trainer to others of its ilk. A pilot who has trained in an Apache has had an opportunity to actually experience what the airplane does as it approaches Vmc. Fortunately, the airplane also recovers we’ll when power on the good engine is reduced and the nose is lowered.

Control harmony is fair. The ailerons are heavier than the rudder and elevators. There’s a substantial pitch up with flap deployment so experienced Apache pilots either drop the flaps in increments in the pattern as speed decays rather than use nose up trim or extend them as the nose drops.

Elevator and rudder trim is via guess-again knobs on the ceiling. This is the only airplane weve encountered that requires nose-up trim after leveling for cruise when the power is reduced. Stalls are without vice and slow flight is solid.

Flight Deck
The gear and flap handle match the airline positioning of the day, gear handle on the copilots side of the cockpit, the reverse of the standard control positioning. There have been inadvertent gear retractions as a result, although the rate of such accidents doesnt seem excessive.

The power levers arent coded by shape. On early Apaches, all of them were painted black, although later versions were color-coded. Instrument location seems almost random, leading to some head turning when flying IFR and potential vertigo. Most Apaches have 36-gallon main fuel tanks and 18-gallon aux tanks.

Either engine can feed from any fuel tank. Standard airplanes had but one generator and one hydraulic pump. Some had only one vacuum pump. Dual vacuum pumps and dual alternators should be already installed on any airplane worth considering.

Apaches can be had for excitingly low prices. But, caution: The airplane is not only nearly half a century old but also quite complex. The flaps and landing gear are hydraulic and the extension speeds are slow, 87 KIAS for the flaps and 109 knots for the gear. Of course, those speeds have been ignored from time to time and the results show in the condition of the legs.

The 14-volt electrical system is not tolerant of age. Over the years, chafing wiring can drive an owner to distraction as switches suddenly turn on the wrong thing or lights dim, flicker and die.

The fuel is carried in bladder tanks, which must be watched for condition and replaced periodically. The hydraulic system can be troublesome if not kept up. Components have to be replaced periodically. Most owners plan on completely replacing all valves every five to 10 years, otherwise the landing gear can give fits.

Considering the forgoing, look on the bright side: The O-320 Lycomings engines have a good rep for solid service.

If youre offered an Apache thats been sitting in the weeds for a few years for a mere $3000, run away. It could bankrupt you. Expect to pay $35,000 to $40,000 for one youd be willing to fly away.

Beechcraft Travel Air
In the 1950s, Beech was building the massive, magnificent, Model 18 as Cessna, Aero Commander and Piper were happily discovering there was a significant market for twins with horizontally opposed, rather than round, engines.

After mature reflection, Beech started a general aviation trend by taking a successful single-engine airplane and splitting its power plant into two units. Thus, the Bonanza morphed into the Travel Air, albeit with tail surfaces from the T-34 Mentor, another successful Beech single. The handling was pure Beechcraft and even now, its the fastest of the light-light twins, slightly besting the Twin Comanche.

In 1958, the Model 95 begat the Travel Air line. Two years later, an optional fifth seat was added and gross weight went up 100 pounds. (We do not recommend using the fifth seat in any light-light twin.)

The 1961 model B95A boasted a stretched cabin, another 100 pound increase in gross weight and fuel-injected engines. The penultimate model appeared in 1966, the D95A, which, with half-inch valves, upped TBO to 2000 hours.

The last of the line, the 1968 E95, had a one-piece, more steeply raked windshield. Slightly more than 700 of the Model 95 series were built before it went gently into the night.

Handling, Performance
The physical handling of the Travel Air was the best of the 1950s and 1960s era light twins. Pilots are uniform in their praise for it. Vmc is for real and must be respected, as with the Apache and Twin Comanche. As a trainer, the Travel Air can turn out competent multi-engine pilots because its not overly docile. But the other side of that coin is that its not for the owner-pilot whos not willing to undergo recurrent training.

The safety record indicates no alarming faults, other than fuel mismanagement. Consistent with other twins, the most commonly seen mechanical problem is with the landing gear; both forgetting to put it down and improper maintenance.

Flight Deck, Maintenance
Instrument positioning leaves much to be desired. The throttles are between the prop and mixture levers, which requires a bit of an adjustment. But those who have accommodated this report that its no big deal.

Elbow and legroom are satisfactory although headroom is tight. The seating position is somewhat erect and leads to comments that its less fatiguing than the more reclined seating positions.

Corrosion is a significant consideration on the magnesium control surfaces of the Travel Air. They should be inspected carefully. Owners report that having a mechanic who knows the control surfaces makes the difference between work thats merely expensive and ruinous remediation.

The bladder fuel tanks seem to last for about 10 years before needing replacement; check that on pre-buy. Keeping the door latched in flight is a significant consideration so the latching mechanism should be checked regularly. There’s an AD for cracks in the forward wing spar carry-through structure. We also recommend keeping track of the five-year overhaul on the Hartzell props, no small expense if needed. The American Bonanza Society has classes and support directed specifically to the Travel Air. We recommend joining even before buying a Travel Air as the organization has a great deal of information available for the prospective purchaser that might preclude latching onto a dog.

Cruise speed makes the Travel Air very attractive in the older light-light twin set, but the anemic single-engine performance calls for a second and maybe a third consideration before buying. We like it as a trainer, but as an owner-flown twin, we can only suggest the purchase of one over a Seminole, Duchess or Cougar if its in absolutely excellent condition.

Twin Comanche
Although the purchase prices have been climbing, the Twin Comanche is the closest thing there is to an economical light twin. It started life as an Apache replacement, using the same 160 HP Lycomings, although they are fuel injected in the Comanche.

Burning about 14 GPH, the Twin Comanche cruises in at 155 to 160 knots. The series proved to be a big hit, some 2150 were built between 1963 and 1972 when Tropical Storm Agnes wiped out the jigs at Pipers Lock Haven plant.

The Twin Comanche is one of those airplanes- like the Cessna Cardinal-that got an undeserved bad reputation from the start. The Twin Comanche black star was for stall-spin accidents, usually following Vmc demonstrations in training.

It hit the training market as the FAA published a widely misinterpreted directive regarding Vmc demonstrations for the multi-engine rating. Instructors and examiners were insisting that Vmc demos be done as low as 500 feet AGL, with predictable fatal results.

An AD boosted Vmc 10 knots to 72 knots and common sense began to prevail on altitudes for the demonstrations. The most recent sweep of NTSB reports on the airplane showed the stall-spin accident is rare.

The PA-30 entered the market in 1963. In 1970 it evolved into the PA-39, with counter-rotating engines. The PA-39 is a much sought after light-light twin with a significant price jump occurring on the used market from the PA-30, which was itself, a most satisfactory airplane for the time. Turbocharging became optional in 1966, allowing high altitude cruise speeds to nudge 190 knots. Most Twin Comanches had four seats, although later ones sported six. The aft two filled the baggage compartment and were appropriate only for the very small. The airplane should best be thought of as comfortable for four.

Depending on the various fuel quantities available over the years, including tip tanks, some Twin Comanches can carry three people for more than 1000 miles at decent speeds.

Handling, Performance
In cruise flight, the Twin Comanche is generally a pleasant flying airplane. Its a pain in the whatsis to land consistently thanks to the laminar flow wings hard-edged stall. Good speed control is essential on final and will generally lead to a landing thats acceptable if not a greaser.

Raising the flaps just before touchdown seems to help, but there are more than a few practitioners of this arcane art who have hit the gear switch instead. The attitude of the airplane on the ground means that on takeoff, unless you replace the nosewheel with a smaller diameter version, the airplane can get airborne below Vmc. Attempting to hold it to a sensible Vmc plus 5 knots results in wheelbarrowing. Those who have installed a smaller diameter nosewheel report that this (mostly) solves the problem.

Handling qualities deteriorate slightly as speed approaches the stall due to loss of control effectiveness. While not unacceptable, we put the overall handling of the Twin Comanche at the bottom of the list.

Flight Deck
Early Twin Comanches carried forward the Piper predilection for installing gauges in vertigo-inducing locations. In 1968, the standard T-panel arrived, a substantial improvement. The fuel selector and gauging systems require review and understanding, particularly on the airplanes with tip tanks; more than one pilot has come to grief due to fuel mismanagement with a full tank available. The wastegate for the turbochargers is not automatic. A separate set of knobs control the turbos after the pilot sets the throttles. It adds to the workload significantly and should be part of an extensive checkout for those who make a purchase.

The Twinkies structure has attracted more than its share of ADs. This is an airplane that requires careful assessment before purchase. And it has its share of oddities. The landing gear uses bungees to assist retraction and these must be replaced every 500 hours. The geardown light indicator wires fold with the gear and thus chafe and wear out. They should be inspected and potentially replaced at each annual.

The most common problem noted with the Twin Comanche is landing with gear up. A significant number of such events were due to failure to properly maintain the gear and, surprisingly, to widespread owner ignorance about how the emergency extension system works. Some said they tried to pump the gear down. They lied. The manual extension system isn’t hydraulic.

The pre-flight fuel draining process has definite shortcomings and has brought down a few airplanes. The drains are operated from inside the cockpit, so fuel cant be sampled without help. There’s an AD on the fuel strainers requiring inspection and replacement. The drains are known to collect water and debris and corrode, potentially allowing water into the engines.

The Twin Comanche remains one of the better buys available in the light-light twin department. Theyre getting long in the tooth, however, and some parts may be a problem.

Our view is that the PA-39, with counter-rotating engines that did away with the critical engine, is the best of the bunch. The good ones are worth the purchase price.

Piper Seminole
The clich applies this time; the third try for Piper was the charm. Piper did its best job with the Seminole. While we don’t feel its as good a trainer as the Apache or Twin Comanche, the Seminole is the best of Pipers light-light twins for the owner or renter.

Reports from owners of the turbocharged versions are particularly positive as these overcome the anemic single-engine service ceiling of the normally aspirated airplanes. Its also the only T-tailed piston Piper that doesnt get poor reviews for handling in pitch on takeoff and landing.

As it did with the Comanche and Lance, Piper made a twin out of the fuselage of a successful single, the Arrow IV. The choice of 180 HP Lycomings as opposed to lower power was wise, particularly in light of the stellar reputation of the O-360s.

The Seminole appeared in the late 1970s and 464 were sold before Pipers financial difficulties slowed production to a crawl. Yet it remains in production today, as the only new light-light twin.

B<>Handling, Performance
In our opinion, the Seminole is not a good multi-engine trainer; its simply too easy to fly. The engines are counter rotating so there’s no critical engine and handling is docile, with good control harmony, better even than most of the Cherokee series.

Vmc is a pokey 56 knots with gross weight stall (clean) at 57 knots. The airplane wont stall and roll over unless the pilot is remarkably dense. The airplane doesnt react violently nor swerve viciously when an engine folds. All good stuff for a rental fleet or owner-flown ship; not good to step-up to a Cessna 310 or a Baron, in our view.

We heard from one very happy owner who runs a turbo Seminole because his normal flying is over mountains. He stays at least 400 pounds under gross weight to be able to fly on one engine anywhere along his route. Even at gross, the drift down characteristic will either give a decent radius to search for an airport or will allow flying to an area where the terrain is lower and single-engine level flight is possible.

Flight Deck
Four people inside a Seminole will be reasonably comfortable and while we would prefer a second cabin door, entry and exit is standard Cherokee; adequate, but not easy. A full fuel load allows 700 pounds in the cabin; comfortable for three and baggage.

Instrument layout is good other than the manifold pressure and tach locations, which are on opposite sides of the power quadrant and down low, a poor location for keeping ones head outside while setting power.

Further, we have yet to understand why Piper continues to waste panel space by providing two tachometers rather than one gauge with two needles, as is done with manifold pressure.

The reason the Seminole is popular as a trainer is because its not expensive to operate and is easy to maintain. Piper did its homework on accessibility, even including a nosecone thats hinged for ease in reaching the systems that live up front.

The engines require inspections of the oil filters every 50 hours-something we recommend in any airplane-and the use of TCP oil additive due to tappet and cam spalling. Increasing tappet size at overhaul eliminates the problem and should have been done on any airplane considered for purchase.

While the addition of turbochargers drives maintenance costs up, blowers on the Seminole don’t seem to generate grumbles from owners. While we strongly recommend watching exhaust systems on any turbocharged airplane carefully, the Seminole seems to escape serious worries.

The AD list is reasonably short. The standard directive on Janitrol heaters applies and can be made less onerous by putting a Hobbs meter on the heater switch. AD79-09-07-the 500-hour Bendix magneto inspection-also applies. The safety record for the Seminole is outstanding. There simply arent many accidents. Consistent with many twins, most accidents involve the landing gear, either brain fade behind the control wheel or gear collapse.

Beechcraft Duchess
Beech did a nice job on this twin. It carries a reasonable load, handles we’ll and the T-tail is not for decoration, as the airplane originally had a conventional tail which proved unsatisfactory during flight test.

Performance is consistent with other twins of the class, although single-engine service ceiling is a bit higher. Owners and renters like the airplane, even though it cannot be operated as cheaply as the Seminole because of Beech part prices.

The Duchess arrived in 1978, about the same time as the Cougar and just a year prior to the Seminole. Beech used the general plan form of the Sierra fuselage and hung two engines, as it had done with the Bonanza/Travel Air earlier.

While the Sierra was woefully slow, the Duchess is every bit as fast as its direct competitor, the Seminole, with an even more comfortable cabin and two entry doors. The general aviation collapse claimed the Duchess as a victim after only five model years and 437 airplanes.

Handling, Performance
On the ground, the soft gear has lead some pilots to embarrassment when they have caught prop tips on less than perfect taxiways or hit other airplanes with a wingtip. The ramp rash accident rate is higher than we expected.

Otherwise the airplane is virtually without vice. Handling is typical Beechcraft, historically a synonym for delightful, although, in common with Beech singles, it does wag its tail in turbulence.

Single-engine handling is similarly easy. Beech opted for counter-rotating engines to do away with the critical engine. It also provided trim tabs for all three axes, making extended flight on one engine a breeze. Cruise is realistically about 150 to 155 knots. Yes, some singles will pass you and you’ll look at a Lance for a long time before you leave it behind. But on those nights in the clag or over water, you’ll be more comfortable than the occupants of any single.

Flight Deck
The Duchess is one comfortable airplane. Its wider than a Baron, has better headroom than almost any twin except the Skymaster and has two doors for the cabin. The panel layout is excellent.

Beech went with the conventional general aviation control configuration for the power quadrant, gear and flaps, which helps transition to other models. Still, this didnt stop pilots from landing gear up with some frequency or retracting the gear on the ground.

The Duchess matches other twins in that the preponderance of its accidents are tied to the landing gear. Simple failure to extend it, retracting it on the ground or improper maintenance of the gear were the root causes.

There are a number of one-time ADs but only one repetitive one without a cure: Its a 100-hour dye-penetrant inspection of the main gear A-frames. If youre buying, insist that all one-time ADs be completed.

Among general areas to watch are chafing of heater ducting on hydraulic and brake lines leading to fluid loss. The place to check is under the copilots seat. Engine mounts should be checked for cracking.

On a pre-buy, look hard for history of a gear-related accident as an estimated 20 percent of all Duchess aircraft have been involved in such an event. Beech part prices continue to lead to owner complaints, but if you can afford a twin in the first place, this may be tolerable.

Grumman Cougar
The Cougar appeared at about the same time as the Duchess and Seminole. It had roughly the same performance on 20 fewer horses per side. It was built for only two years, 1978 and 1979 with about 115 completed. We hear persistent rumors that the model will enter production again but we’ll believe it when we see it.

Grumman American entered the light-light twin fray head-to-head with Beech and Piper. Characteristically, Grumman approached the process using smaller engines and used aerodynamics and a smaller cabin to obtain the same performance of the Beech and Piper airplanes. Unfortunately, the general aviation collapse of the 1980s stopped Grumman dead, so Cougars were never a major player.

Thats too bad, as Cougar owners rave about their airplanes. A Cougar is rarely seen on the market and when one is offered, it usually goes quickly.

With only about 100 in existence, there arent enough to make any objective observations about accident rates or fleet wide maintenance problems.

Handling, Performance
The Cougar doesnt have the counter-rotating engines found in the Duchess or Seminole; however, its single-engine handling is nearly as docile. Owners and instructors report that its easy to handle on one engine but all note that whether it will go up, hold altitude or descend is dependent on weight and temperature.

Everyone we spoke to was complimentary of the handling of the airplane in all flight conditions, particularly in comparison to older light-light twins such as the Twin Comanche.

The Flight Deck
The panel is we’ll laid out and we especially like the fuel selector, with the pointer positioned on the fuel tank desired, or to the off position. It doesnt get any simpler.

The cabin is more than adequate in terms of hip and legroom, although tall pilots are a little short on headroom. The rear seats are comfortable, however, theyre stepped down slightly from the front, limiting forward visibility.

The wings bonded structure is strong and durable and the de-bonding that affected some singles happened on model years before the Cougar came out. Owners tell us the Cougar is a simple airplane. They say they replace tires and brakes and overhaul engines. The electro-hydraulic landing gear has a power pack similar to the Piper Arrow has a good service history.

The engines are carbureted and have a reputation for being nearly as bulletproof as the 180 HP Lycomings. The only problem noted by owners was with fuel leaking past the seals on the primer and causing hydraulic lock in the cylinders on starting, leading to bent rods. There’s a fix for the primer that we recommend be installed on any airplane you consider buying.

There is no combustion heater in the Cougar so you don’t have to light a fire in the airplane to stay warm. Heat is provided from muffs on the engines, as with single-engine airplanes. One owner who runs a Cougar and a Mooney 231 said that maintenance between the two airplanes is annually within $100 of each other.

Performance is outstanding on the available power if the pilot understands that single-engine climb is terrible. Maintenance is dirt simple. We feel this is probably the best of the light-light twins for owner-flown operations, its efficiency and handling putting it just a bit ahead of the Beech Duchess.

Recognizing that the single determining safety variable for owner-flown twins is recency of training, we like the Piper Seminole, Beech Duchess and Grumman Cougar in that order for pure ease of operation and safety.

For the same reasons, we don’t like them as trainers; theyre too easy to handle and don’t reflect the real world of fearsome Vmc issues and critical engine considerations.

Based on our review of these six light-light twins, the newer ones are just plain better when crashworthiness, ease of maintenance and flight deck layout is considered. We feel the best is the Grumman Cougar, followed closely by the Beech Duchess and Piper Seminole.

Rounding out the list we prefer the Twin Comanche, Beech Travel Air and finally the Apache. Nice airplanes in their heyday, but antiquated systems make them less desirable in the real world.

Also With This Article
Click here to view charts for Price Comparisons, Cruise Speeds and Payload.
Click here to view Hard Specs.
Click here to view “What Single-Engine Performance?”
Click here to view “Safety Margin? Perhaps Not Much.”

by Rick Durden

Rick Durden is an aviation attorney and frequent contributor to Aviation Consumer. Hes a partner in an Aztec.