Aerospatiale TB-20

The Trinidad isn't the fastest retractable on the block but it excels in comfort and load carrying capability.

The French have always done things a little differently. Sometimes a lot differently, as is evident in the Aerospatiale line of piston singles.

While European manufacturers have not proven a powerhouse of GA manufacturing, Aerospatiale has achieved an enduring if not overwhelming presence with its single-engine trainers and cruisers.

The TB-20 Trinidad, especially, looks trim and sleek with a sports-car like interior one aviation writer once described as a Cherokee done over by Club Med. These airplanes also have gull-wing doors, lots of class and, coming soon, the option of diesel powerplants.

Sales of the TB-20 have been lukewarm in the U.S., with ups and downs since the model was introduced at the Paris airshow in 1977. There are some 270 TB-20/21 registered in the U.S.

Significantly, however, as U.S. manufacturers were shutting down their plants in reaction to weak market conditions, Socata kept at it, delivering a steady trickle of airplanes to what it sees as a world market.

Model History
The Trinidad is the top of the line of a small family (five) of single-engine aircraft developed and built by Socata in Tarbes, France. Socata is the general aviation division of the government-owned aerospace conglomerate, Aerospatiale.

The so-called Caribbean line of aircraft includes the TB-9 Tampico and -10 Tobago, fixed-gear singles of 160 and 180 HP and the 250-HP, retractable-gear TB-20 Trinidad and -21-TC turbocharged Trinidad. In this regard, the French have largely duplicated the American marketing strategy of a model for every price and usage strata.

The models share a common fuselage, wing and empennage, which has obvious advantages in production economies, something U.S. airframers haven’t always done.

In practice, this means that a batch of fuselages and flying surfaces can be built and kept on the shelf until orders need to be filled. It also means that for the Caribbean series, no distinction is drawn between the airframes: The two variants co-exist within the same run of serial numbers.

To date, the total worldwide TB-20/21 population tops out at about 730 airframes worldwide. After its promo appearance at the Paris Air Show in 1977, the TB-20 was awarded French type certification in December 1981. The first Trinidad arrived in the U.S. during the summer of 1983, with FAA type approval the following year. The turbocharged TB-21 gained FAA certification in March of 1986.

Acceptance of these models can best be described as mixed. The French had been in the U.S. before with the Rallye and had not done well with it in a market that still supported volume sales.

After a couple of failed efforts to introduce the TB line, Socata established its own operation just outside of Dallas, Texas. Aerospatiale General Aviation (AGA) shared facilities with Aerospatiale Helicopter Corp. in Grand Prairie. This facility was phased out in favor of a single distrbutor in Florida and as of this writing, Socata has a corporate presence at North Perry Airport in Pembroke Pines, Florida. (954-893-1400.)

TB-20 models built between 1977 and 2000 are so-called “Generation One” aircraft and most of those already in the field are of this vintage. In early 2000, Socata introduced the “Generation Two” or GT line, with upgrades to the original aircraft design.

The GTs have essentially the same airframe, controls and powerplant as the originals but they have a modified carbon-fiber based cockpit roof which increases headroom and cabin volume, thus addressing complaints from taller pilots. Other minor changes have been introduced. In 1990, starting with serial number 950, maximum landing weight was increased to 3086 pounds. Unfortunately, structural modifications were made to the landing gear attach points and they are not retrofittable to earlier models.

At the same time, the electrical system was changed from 14 to 28 volts. A change to a higher-speed starter motor followed. To its credit, the detail and systems changes Aerospatiale/ Socata has made to the design are almost completely the result of customer experience. Also to its credit, according to reader feedback, the company has been responsive to customer requests for assistance, although one former owner who contacted us complained of weak parts support.

The relatively simple, monocoque fuselage has a comparatively low parts count compared to like aircraft. According to the company, it takes about 600 man hours to construct a Trinidad.

This is lower than, for instance, the hours required to build a Mooney or Bonanza airframe. Most of the cabin is fabricated from reinforced glass fiber which sits on top of the load-bearing structure, the fuselage tub.

Flight controls are actuated by push rods rather than the more typical cables, which gives a positive – albeit a bit heavy – control feel similar to Mooney models. Since much of the wing trailing edge is occupied by the flaps, the ailerons are short span. It’s a simple, yet sleek design.

A prominent distinction is the vertical stabilizer, which is located forward of the horizontal, all-flying tail or stabilator. Both control surfaces have trim tabs. Pitch trim is via an anti-servo tab.

The rudder trim tab is an additional surface appended to the rudder that looks like an afterthought. The main landing gear is a trailing link design that favors pilots who occasionally botch landings; it soaks up the bumps well.

For power, the TB-20 uses the Lycoming IO-540-C4D5D version rated at a conservative 250 HP. The turbocharged TB-21TC combines the AB1AD version of the same powerplant, also rated at 250 HP, with a variable wastegate-controller Garrett AiResearch turbocharger.

Recommended TBO for both is 2000 hours, which is a plus. Also a plus is that none of these engines was affected by the massive recall of 300 HP and over Lycomings in the fall of 2002.

But that doesn’t mean TB-20 owners have an easy time of it. As with any large engine, overhaul costs are relatively high. In a phenomenon unique in recent experience, there’s actually good news about the cost of operating the turbocharged engine.

When we covered the Trinidad some years ago, our sources quoted an average overhaul cost for the turbocharged engine of a whopping $30,000. To quote one facility manager we talked to, “…it is a very expensive engine to overhaul, and we don’t see many of them.” Since then, average cost for overhaul of the turbo engine actually dropped, to about $23,000, due in large part to intense competition in the cylinder field. As of early 2003, overhaul costs have again inched up, hovering around the $29,000 mark. The normally aspirated variant costs about $20,000 to overhaul, variable with cylinder choice.

Cabin Comfort, Loading
Another feature that distinguishes the TB series is the top-hinged, gull-wing cabin doors. These make access to any seat quite simple, with a minimum of fumbling and clambering. The cockpit/cabin is modern looking and is well organized.

It’s 50 inches wide, the most expansive in its class. In fact, it’s one inch wider than the Piper PA-32 family of cabin-class singles. The Trinidad can accommodate up to five people. There are individual bucket seats up front.

Up to three passengers can be carried on the rear bench seat when the optional center lap belts are installed, although the pax will have to be small. The airplane is quite comfortable for four, although tall individuals have noted tight headroom, particularly in the rear. The newer GT models address this. The seats include an adjustable lumbar support.

To go with its notable spaciousness and comfort, the Trinidad can carry a comparatively hefty pay-load. It’s almost a full-tanks and full-seats airplane, which is unusual for singles and light twins. It also has a generous CG range to permit loading flexibility.

At an average equipped weight of 1990 pounds, payload with full fuel (86.2 gallons usable/517.2 pounds) is 589 pounds. That works out to 3 1/2 170-pounders.

To put things in perspective, its full-fuel payload exceeds that of any other four-place single and even beats the A36 and B36TC Bonanzas. Among singles, only the Cessna 210 surpasses the TB-20’s payload capability, but with less comfort, at least with regard to seat design.

Visibility from all seats is first rate. The windshield and side windows wrap up into the roof line and the windshield extends down alongside the panel, meaning that the pilot can actually see down and forward a bit. That’s unusual in low-wing airplanes and is a nice benefit.

Further, the seating position is high and the window sills are low, rather like modern fighter aircraft. Ergonomically, the cockpit is well organized. The panel is a modular arrangement with the right-side gauges mounted at an angle to face the pilot squarely. The center console has a trim wheel cleverly placed directly under the pilot’s hand when it’s on the throttle; trim adjustments during final approach are very easy.

Models built before 1987 have the fuel selector mounted to the left of and just below the pilot’s yoke, an arrangement that was the subject of an AD .

The three panel modules can be released quickly and tilted back for maintenance access to the instruments and avionics, making for easier repairs. Additional access panels are provided in the glareshield. The interior is well thought out, in our view, providing a lot of pockets and crannies for manuals, charts and odd pieces of gear. The biggest drawback is the relatively small, odd-shaped baggage door. It’s hinged at the bottom and when fully opened, it projects quite a ways.

Care must be taken when loading the baggage bay. Access to the baggage bay for bulkier items than can fit through the door can be gained from inside the cabin. The rear seat back can be folded down or removed, which opens up a spacious area behind the two forward seats.

Flying It
There’s nothing peculiar about operating the TB-20. From pre- to post-flight, the airplane is quite conventional; anyone stepping up from a Piper or Cessna will have no trouble with it.

There are some quirks: Inspection of the engine compartment is difficult because a number of fasteners must be unscrewed. Then, the one-piece cowl has to be put in a safe place while the inspection is performed so that a gust doesn’t send it sailing down the ramp.

Many owners probably won’t bother frequently enough to catch the odd deteriorating hose, loose connection or nesting bird before such oversights become a problem. (Mooneys suffer a similar shortcoming.)

The cockpit layout is generally good but it takes some getting used to. For example, the instruments have vertical temperature and pressure gauges, not analog dials.

Getting airborne is nothing unusual. Normal takeoffs call for 10 degrees of flap. The standard flap control is an electric switch that permits settings anywhere from up to full-down (40 degrees) to any increment in between. It must be monitored during operation to get the right setting.

Many Trinidads are fitted with the optional pre-select switch, which offers flaps retracted, 10 and 40 degrees. In maximum performance takeoffs, and climbing at best angle, the forward view is filled with cowling. You’ll need to S-turn a little to get a full view of what’s ahead. Rate of climb at Vy of 95 KIAS is 1250 FPM. Critical speeds are Vne, 187 KIAS; Va (ma-neuvering) 129 KIAS; Vlo (gear operating) 129 KIAS; and Vfe (max flap extended) 103 KIAS.

The airplane is not blisteringly fast for having such a large engine nor is it as slick in the descent as even some older Mooneys. Nonetheless, descent takes some planning, due to relatively low Vlo and Vfe. One option is to lower the gear at the top of descent and use the wheels as speed brakes.

The Trinidad’s control response is good, with the highest noticeable effort in roll. The ailerons aren’t large and under airload, the push rods may pick up some operating friction. This won’t be objectionable to anyone stepping into a Trinidad from a Cessna but a Bonanza pilot will notice.

Pitch and yaw control effort is lower. So it’s more an issue of balance, or control harmony, than hard work. The good trade-off is that the airplane, thanks also in part to its comparatively high wing loading, handles turbulence well. It also displays good manners in the clouds, with no tendency toward pitch twitchiness or wing fall off.

Slow flight handling is good, too. While the stall speeds are marginally higher than with other singles, the stall is mild. The typical result is more of a high rate of sink rather than a pronounced break.

The flight controls are fully functional right through the stall. Intentionally cross-controlling near the stall or even in it produces sink rather than a snap.

Pitch change with initial flap extension is minimal. It’s more pronounced when full flaps are selected, particularly at the higher end of the allowable speed range. Saving full flaps until the landing is assured means adjusting trim or accepting high pitch forces down to the flare, at which point the up trim has to be put back in.

Full flaps generate a lot of drag, which means either accepting a steeper approach (good for obstacle clearance) or a partial-power approach. Low-speed technique is rewarded with satisfyingly short landing performance. In this respect, the TB-20 shows a bit of the Rallye heritage. Landings, except for the most highly botched and abusive, can be done repeatedly with grace.

Lightly loaded, with just the pilot, it takes more attention, because CG is forward. But its manners (and willingness to forgive) are very good.

It’s axiomatic in airplanes that you never get something for nothing. In the Trinidad, this translates to modest cruise performance, thanks partly to that wide cabin. According to factory figures, 75 percent power at 8000 feet nets a true airspeed of 159 knots. Endurance with 45-minute reserve is 5.65 hours.

At the same altitude, 65 percent generates 149 knots and a bladder-busting 6.4 hours endurance. The turbocharged version doesn’t perform quite as well at lower altitudes, which is typical of most turbo models.

The crossover point comes at about 12,000 feet. At its maximum operating altitude of 25,000 feet, 75 percent power generates a true airspeed of 187 knots and endurance of 4.5 hours; 65 percent power produces 169 knots and 6.2 hours. In the real world, say owners, the airplanes are a bit slower than the POH values.

Maintenance, ADs
Owners report no characteristic maintenanace bugaboos and we get mixed opinions on parts support. Parts are generally expensive, however.

Most of the changes made to the TBs are reflected in service bulletins and airworthiness directives. About a dozen ADs had been issued on the TB-20 and -21 by early 2003. Most of these are blanket ADs affecting many different aircraft: paper induction air filters, Bendix ignition switches, Bendix magneto impulse couplings, Hartzell propellers and Airborne vacuum pumps. Several blanket ADs cover various aspects of Lycoming engines (91-14-22, calling for inspection of the crank and associated parts for corrosion following a prop strike or at overhaul). An AD issued in 1990 requires a one-time inspection of oil coolers on all TB series airplanes for cracks and what the text merely calls “distortions.” If anything is amiss, the oil cooler must be replaced. The AD on the fuel system mentioned earlier was issued to deal with a few instances of fuel starvation.

In the original design, fuel lines run from the tanks forward and up to the panel-mounted fuel selector. Two conditions could occur: Fuel could drain to the low point, causing the fuel pump to cavitate. The original Dukes fuel boost pump is lubricated by fuel. Dry lines resulted in its failure. Or, vapor lock could occur, blocking normal fuel flow. The fix for the original system is to replace the boost pump with a wet-or-dry Weldon pump and to install a check valve in the line to preclude draining.

In 1987 and later models, the fuel selector has been relocated to the center console. Also, it has been modified so that it’s not necessary to pass through “off” when changing tanks.

Three ADs have been issued on the horizontal tail; two of them require repetitive inspections. One requires replacement of the elevator trim tab control attachment. The second requires repetitive (every 100 hours) inspection of the stabilator actuator rod end assembly and attach fittings. Another repetitive AD affects the ailerons. The skin and balance weight attach rivets must be inspected every 100 hours. Substantial cracking requires aileron replacement.

An improved part eliminates the inspection requirement. The most recent AD?2002-20-04?requires installation of an exhaust extension to prevent carbon monoxide incursion into the cockpit.

Owner Comments
I have owned a 1989 Trinidad since 1992. Overall, we’ve been extremely happy. It’s fun to fly, has good speed and great comfort and the visibility and useful load are excellent.

Here’s the good:

• Stable in flight, push-rods on controls give a sturdier, more solid feeling than cables

• Speed: between 158 and 162 KIAS at 75 percent power, 80 percent of the time at 6000 to 8000 feet. Combined with the usable fuel, this can give a good range. I made Wilmington, Delaware to West Palm Beach, Florida non-stop both ways last month with 45 minutes reserve.

• The cabin is roomy enough for two guys to share the front seats and rarely bump. Visibility is great in all but climbs under 100 knots. Cruise climb at roughly 115 knots gives good forward visibility.

• Useful load is great. We have 1135 pounds. With full fuel, that’s 617 pounds of payload. Each year, four full-sized guys fly up to Penn State for a football game and despite our weights of more than 800 pounds, we can make the one-hour flight with well over an hour fuel reserve by trading the usable fuel for passengers.

• As long as the heaviest passengers are kept in the front seats, it’s virtually impossible to get out of CG balance. Fuel burn goes almost right down the middle of the CG.

• Parts have never been an issue. Virtually everything we’ve needed has been in the U.S. and once something was overnighted – with customs it took two nights – from France.

• The user group is superb with quick answers for most issues. Often, a search of the maintenance section has immediately answered maintenance questions, no small issue since most FBOs don’t have a lot of experience with these airplanes.

• Since the panel was designed for modern IFR flight, it’s very well laid out, with right side instruments canted to the pilot.

And the bad:

• With all the glass, it can get very hot in the summer. Taxiing with the door propped open is essential.

• The headspace can be limited if you’re tall – the front seats must be reclined a bit, which is a natural orientation during flight, due to the deck angle. You will occasionally hit the roof liner if you move around a lot. I understand later versions improved upon this (ours was serial number 916). I’m 6-foot-1-inch and my partner is three inches taller. We have adapted easily.

• Vno is low at 151 knots and this can be a problem when low unless you don’t mind going into the yellow arc a lot. Departing Wilmington to the north, we’re always kept at 4000 feet until passing Pottstown, due to Philly arrivals. I often have to back off from 75 percent power to keep under Vno if turbulent.

• The steps are poorly made and seem to break often. We’ve now broken both over 10 years and will not replace them as many owners apparently do.

• Since there aren’t a zillion of these airplanes, there are relatively few mods available. But some important ones are available, such as three – bladed props, TKS, and of course, the diesel conversion, which is in the works.

In sum, a great compromise of speed, comfort, range and useful load. I’d be happy to continue flying this type for a long time.

-Andrew Doorey
Wilmington, Delaware

I own a 1986 Trinidad that I purchased used in 1993, with a total engine and airframe time of 1094 hours. It now has 2060 hours and is in the shop while its engine is being overhauled by Firewall Forward.

I use my Trinidad for a mix of business (70 percent) and pleasure (30 percent) and currently average about 100 hours of flying per year. I count myself as a very satisfied owner, having flown the airplane as far west as Arizona, as far north as Vermont, as far east as Nantucket and south to the out-islands of the Bahamas.

My flights have included hard IFR to minimums and very wet, turbulent weather. The longest single leg has been five hours from Fort Pierce, Florida to Nashville, Tennessee. With 86 gallons of usable fuel, the airplane will outlast my personal comfort limits.

It is a very stable airplane and will cruise at 160 knots (75 percent at 15 GPH) although I typically fly at 150 knots (65 percent at 13.5 GPH). With full fuel, the airplane can carry 640 pounds of passengers and luggage.

The center console and doors for both pilot and copilot make for a very comfortable ride, with windows that provide remarkable visibility when compared to other low-wing aircraft in which I have flown.

Even at 17 years old, my TB-20 still draws an admiring crowd on the ramp because its appearance is so different from other aircraft.

The airplane came with an approach-capable autopilot and a Shadin fuel flow computer. Since purchasing the airplane, I have added a Stormscope WX-950, an Bendix/King KLN 90A IFR GPS, a three-blade propeller (no noticeable change in performance, but more ground clearance when parking in grass), new carpet and sheepskin seats sewn in as an integral part of the upholstery.

I keep it hangared at Nashville International and use a large shop on the field – Stevens Aviation – for maintenance.

Plans for future upgrades include an electric standby vacuum pump to be installed along with the overhauled engine and an HSI.

Expenses for the airplane include insurance at about $2000 annually, thorough annual inspections that average $4000 each year and other miscellaneous maintenance costs of $2000 annually. I don’t skimp on maintenance, preferring to catch problems before they occur.

My shop tells me that the service manuals are comprehensive if occasionally hard to understand, rivaling what they see for a Beech King Air in the amount of detailed procedures that are spelled out.

Only twice have I needed a part that required shipment from France, and generally the support from Socata in Florida has been excellent.

I have made one emergency landing in this airplane. It was the result of a fuel line connector that separated shortly after takeoff, thereby stopping the engine. It ended without incident on the taxiway of a parallel runway that was closed for repairs.

My only beef with the airplane concerns the fuel gauges. They are practically useless, in my view. Replacement sending units from Socata weren’t any better, so my shop reinstalled the originals.

I rely on full tanks at the start of a trip and my Shadin fuel computer for accurate fuel management. I understand that Socata is about to come out with a kit that provides a low-fuel warning in the cockpit. It’s about time.

I wish they would re-engineer an entirely new fuel gauge system for those of us loyal to our older airplanes that have 14-volt electrical systems.

If I were in the market for a new airplane, I’d buy another Trinidad, although I still think the window lines of the new model look odd.

-Mac Moore
Franklin, Tennessee

I purchased a 1984 Trinidad in 1995 and sold it three years later. Thankfully, the airplane sold for a good price, due to the incredible efforts of my mechanic.

First, the bad news; the parts were expensive, beyond even Beechcraft prices.

The exhaust pipes came to $2000. The landing gear actuating stays – which should be replaced via a service bulletin – were $900 per gear leg, plus about seven hours of labor. Even a simple airbox was a cool $1100. And these prices are five years old.

Ordering parts from the factory was always a chore. After one year of getting the wrong parts, my purchase orders would have a long, verbal description of the part, along with the part number. The parts manual was horrific. I own three other airplanes and this was one of the most difficult to maintain.

At one point, I was sent three bad parking brake valves. Not only was it the most expensive valve of its type, it took three tries to get one that worked. It’s built with ungainly rivets. The tie down rings were paper thin. The elevator bracket was made of thin metal.

Even though I got a very good pre-buy inspection, there were many items that I could not anticipate, such as the four vacuum pumps, the HSI gyro and a useless intercom, in my estimation.

Now for the good news: this airplane is extremely stable in IFR and it’s simple to fly. This was my first complex airplane purchase and it took about two hours to get up to speed.

When you use full flaps, the airplane pitches down for a full view of the runway. Only the most incompetent pilot couldn’t handle this airplane. The interior is cavernous and is the best thing about the type. I could carry four adults from Teterboro to Block Island in under an hour in complete comfort, or three people could go to Fort Lauderdale non-stop.

It’s slow, when you consider it has an IO-540. I used to file at 157 knots TAS. But you don’t feel like a sardine after a long flight. On long legs, I let the engine loaf at 65 percent power. At 7000 feet this is 2300 RPM and 20.7 inches MP, with fuel consumption at 14 GPH. At 75 percent power, the de-rated engine is still loafing.

While not as supple as a Bonanza on the flight controls, it’s stable in turbulence. The airplane refuses to do anything bizarre.

So it’s a mixed bag with Socata: great personal comfort but nightmarish prices for parts. Pick your poison!

-Jim Kafadar
Linden, New Jersey

Also With This Article
Click here to view “Socata TB-20 Trinidad Resale Values.”
Click here to view “Accident Record: No Apparent Bad Habits.”