The formula for high speed in airplanes is fairly simple. Nip away at the airframe drag as much as practical then stuff in the largest engine you can and hope you can find room for fuel to run the thing.
That sums up the Mooney M20M TLS, the fastest Mooney the factory ever turned out even if, arguably, its not the best. (We think the Ovation deserves that title.)
Nonetheless, the TLS is impressive. Surrounded with hype during its development, the TLS has a brutish 270-HP, turbocharged, intercooled Lycoming TIO-540- AF1A that gives it heroic climb rates, brisk cruises speed and a thirsty fuel flow to match, hardly the traditional stuff of Mooneys.
For anyone who has ever flown all of the Mooney models, the TLS is sometimes described as, well, rude. While the J-model perks along on its delicate four-cylinder Lyc, the TLS roars and rumbles and virtually leaps into the flight levels, leaving everything behind in a wake of unburned hydrocarbons. (Its not the most efficient ride in the world.)
Nonetheless, owners weve spoken to rave about the TLS. Says one: The TLS lacks the efficiency of the rest of the product line, but speed, rather than efficiency, is what this model is all about. We agree.
Model History
When the TLS was introduced in 1989, Mooney was in need of a hit. The ill-started Porsche-powered PFM had come out a year before but the market timing was bad and the airplane-although an innovative departure with its single-lever power control-was a sales flop. But the PFM pioneered the long-body fuselage which ultimately morphed into the Ovation and TLS.
Mooney hit pay dirt with the TLS, as at least some buyers gravitated towards ultimate performance and away from the traditional Mooney efficiency. The following year, Mooney killed the 252TSE, allowing the TLS to reign supreme as the companys flagship high-altitude performer.
Few changes have occurred in the decade since its introduction. Oxygen and speed brakes, formerly options, were made standard on 1996 models and in 1997 the name was changed to TLS Bravo, coinciding with a modification to the engine oil system which reduced valve wear and upper end overheating problems.
To date, about 310 have been built. As the Used Aircraft Guide is being prepared, Mooney is once again emerging from bankruptcy. Base price on a new Bravo-everyone still calls it the TLS-is $399,000, having been reduced for competitive reasons when the company was sold to its new owners.
Compared to the short-body Mooneys, the TLS is obviously different. The rear seat and aft bulkhead have been moved back to provide more interior space but preserve basically the same baggage area. Also, the panel was redesigned and is noticeably higher than in the older Mooneys.
This allows more stuff to be shoehorned into the panel but it cramps the already stingy outside view. There’s more knee room under the panel, too. The organization of the panel is improved, with engine instruments moved from the right side to in front of the pilot.
The six-cylinder Lycoming is balanced by a slight increase in elevator area and a second battery located in the tail cone. The engine cowl, which has large, un- Mooney-like air intakes-including a big NACA duct to supply air to the intercooler, is lighter than the 252s. The cowl flaps are electrically operated and infinitely adjustable, which is a plus, since its sometimes necessary to have them open in cruise to keep engine temps in line.
The landing/taxi lights are mounted in the wing leading edge, as in the Ovation. This is a plus on two counts: the lamps don’t get creamed by the Lycs vibration and they do an altogether better job of illuminating the runway.
Systems
In addition to dual batteries, the considerable electrical demand is supplied by dual, 70-amp alternators. Available equipment includes a mechanically driven standby vacuum pump, with a dedicated switch on the panel to turn it on.
On one TLS we recently flew suffered a vacuum pump failure and the standby also failed, a not uncommon occurrence, were told.
Another first on the TLS is rudder trim.
Actually, its an electrically actuated, bungee-controlled rudder bias system, not an anti-servo tab. While maintaining yaw trim on smaller-engined Mooneys is not a chore, when you have to drag an airplane into the flight levels for 20 to 30 minutes, your right leg gets rubbery on the rudder. The trim helps.
The basic airplane comes complete with a 115-cubic-foot oxygen system and speed brakes. Later models are also equipped with TKS de-icing and early models that don’t have it can be retrofitted. As a premium model, the TLS was usually delivered loaded with avionics. Earlier ones have Bendix/King KLN88 lorans-since supplanted by KLN90B IFR GPS-and full Bendix/King panels.
Some even have Bendix/King electronic horizontal situation indicators (EHSI) as an option, something found only in jets and turboprops when the TLS first rolled out. New TLSs have the Garmin 530/430 package and many earlier models have been retrofitted.
Handling
Quite a few pilots have shied away from Mooneys because of their handling characteristics and the fact that spot-on speed control is more important than in many other singles. While thats true, its also true that both the TLS and Ovation are much easier to land than the short-body Mooneys.
The additional weight and longer airframe make it childs play to get a greaser every time. Although you can provoke the TLS into the famous Mooney crow hop, it takes effort to do it. And if it gets out of control, the landing gear and prop will take a hit. Speed control at touchdown is critical. The TLS will do nicely at 75 knots over the fence; 90 knots is too fast.
Pilots with Mooney experience will adjust to the TLS quickly, although there are more things to attend to, such as the rudder trim, the cowl flaps and, above all, engine management. Power settings are made easier by the variable density wastegate controller on the turbocharger.
Mooney provides a simplified power-setting chart etched into the pilot-side visor but, nonetheless, the engine does require some fiddling and fussing. But not nearly as much as the 231, which lacks a proper wastegate.
Rotation at takeoff and getting the attitude right for landing are a bit easier. CG is a bit further aft and the elevator is a tad more powerful. If youre primarily a Beech, Cessna or Piper pilot, you’ll find the Mooney has some idiosyncrasies.
One is seating position. The seat level is low, almost putting the pilots butt on the floor. Seat height and angle are adjustable but compared to say, a Cessna 210 or V-tail, you’ll feel like a tank driver in a hatch.
The Mooney wont tolerate hard, fast touchdown on three wheels or slight nose low. It has no oleo struts, just hard rubber donuts in the gear legs and these can be unyielding, to put it generously. And watch the turn radius; the Mooney is somewhat limited compared to other models.
Some pilots new to the long body Mooneys experience a tendency to over-rotate on takeoff, which causes a momentary pitch bobble. Watch for it and you wont have a problem with it.
In-flight manners are good. The controls-particularly ailerons-feel a bit heavy, mainly due to control friction. The rudder is the lightest of the three axes. Control actuation is via push-pull tubes rather than cables and properly rigged Mooneys have good, precise handling. They handle turbulence we’ll but there is some tail wagging.
Precise Flight speed brakes are standard on the TLS and most owners weve heard from seem to think theyre must-have equipment. The speed boards simplify power management and allow higher power setting during rapid descents.
They don’t have much effect at low speeds but you can deploy them at any speed up to Vne and theyll slow the airplane in a hurry. don’t throw them out in ice, however. They may ice up and fail to retract.
In earlier Mooneys, both gear and flap extension speeds were painfully low, which is one reason you see speed brakes on 201s. Flap extension speed is still low on the TLS (110 KIAS) but gear extension speed has been increased to 140 KIAS. There’s still a Vlo for retraction at 106 knots, however. Once the gear is out, maximum speed is 165 knots.
As with earlier Mooneys, there’s a pitch trim change with flaps; you’ll have to trim nose-up to trim off the pressure. The lower the indicated airspeed, the less obvious the trim change. However, transition from power off or low-power approach with full flaps to a go-around or missed approach produces an immediate pitch up that requires attention-getting elevator effort to correct. No sweat, as long as youre ready for it.
Performance
There’s no other way to say it than this: the TLS just goes like hell. Flat out, its a 220-knot airplane in the flight levels, if youre willing to pay the fuel bill.
The engine isn’t highly stressed at the 270-HP rating since variants of the TIO-540 crank out up to 350 HP. TBO is set at a respectable (for turbos) 2000 hours. To feed the thirsty engine, fuel capacity has been increased to 96 gallons, 89 gallons or 534 pounds of which is usable.
Best angle (Vx is 80 KIAS) produces a high 703 feet/NM climb gradient but no forward visibility. Best rate (Vy is 105) results in an impressive 1230 FPM, also making visibility in front next to nil. Thats at gross weight, by the way. At light weights, the airplane will do 1500 FPM, initially. A more sedate cruise climb speed from 120 to 140 KIAS should be used. The latter still produces a healthy 800 FPM, with good forward visibility.
Flight planning decisions are critical in the TLS because it really does carry enough fuel to match its prodigious fuel flow. (It needs 120 gallons.) You can storm along at FL250 truing 223 knots-in the speed range of many turboprops.
Burning 20.5 GPH, you can do this for about three hours. That doesnt provide much range, even if most people consider that a reasonable human endurance. Its fine for show-off time or to bag the bragging rights at the bar. (…I passed that King Air like he was standing still.)
Some owners do, in fact, fly the airplanes flat out, reasoning that speed is the need, not fuel economy. However, setting power for best economy rather than best power costs only two or three knots at most altitudes and power settings in exchange for two or three gallons less fuel consumption. Compromising on lower power settings, particularly where winds are in your favor, can extend endurance to as much as six hours, plus reserve. Not bad for an airplane still tooling along at 200 knots or so.
At FL 200, maximum cruise power of 2400 RPM/34 inches MP and 17.6 GPH results in 204 KTAS. Cutting power and reducing fuel flow to 16.6 GPH still gives 202 knots. At below-oxygen altitudes, the TLS can still churn out impressive speeds: for instance, 195 KTAS at 12,000 feet, according to some owners.
What many owners most want is more gas; another 30 or 40 gallons would be perfect. The TLS certainly has the power to carry it, but alas, Mooney hasnt figured out a way-or at least offered a way-to stuff it into the wings.
Payload, Comfort
There’s no doubt that the long-body fuselage is more comfortable for passengers and crew than the shorter J/K series airplanes. And Mooney has made better use of that cabin space, too. Rear-seat leg room is better and the illusion of space created by the new, larger windows, helps. It also improves pilot visibility to the rear.
Baggage space is adequate at just under 21 cubic feet and the baggage compartment is longer than on the short-body airplanes. Maximum structural load is 130 pounds.
Seats in the TLS are three-way adjustable, and the front seats include an adjustable (inflatable) lumbar support. A nice touch is the way the rear seat backs fold down to provide a cargo compartment in back. The rear seat cushions can be yanked out to allow this.
Payload, as mentioned earlier, is adequate, even with full fuel. The TLS is not the load hauler that airplanes like the 210 or Bonanza are, but its in the ball park: full fuel and two people and some peanuts or two big and one or two small people with full fuel. Owners who didnt equip their TLS with maximum avionics can probably enjoy a four-person with full fuel payload.
When first introduced, the TLS had gross weight of 3200 pounds, later raised to 3368 pounds, with typical empty weights in 2000 to 2100-pound range. Although there’s no zero-fuel limit, the TLS does have a max landing weight of 3200 pounds.
Cabin heating and ventilation are excellent, the best of any of the Mooneys. As with earlier models, to get decent heat output, the cowl flaps have to be closed. The cabin is appointed with nice touches, such as reading lights and oxygen ports on the overhead panel.
Engine, Maintenance
In the summer of 2002, Lycoming announced a major recall of crankshafts, a development well-detailed elsewhere in this issue. Nonetheless, the under 300-HP versions of the 540 series engines used in the TLS have had good service history.
Early on, the TLS engine had problems with premature valve guide wear. Lycoming and Mooney fixed this by running oil lines into the head to pressure lubricate the exhaust valve, converting the engine into a TIO-540-AF1B from a AF1A. The shorthand for this, the Bravo mod, stuck and Mooney adopted it as the model name.
The Bravo mod was introduced in 1996 and many earlier TLSs with the older head design have been converted. But not all have. When shopping for a used airplane, the first thing to check is whether the wet head Bravo mod has been done.
This is not a cheap engine to overhaul. If done right, budget about $30,000 for the job, to include new cylinders. If you treat the engine with respect, and it treats you well, that works out to $15 per flying hour just for the engine reserve. Add in fuel and general maintenance and TLS hourly operating costs are easily in the $90 range.
Some owners have complained that the Lycoming has an unpleasant, rough vibration signature and it does. Its not nearly as smooth as the IO-550 Continental used in the Ovation. An improved engine mount-which appeared in 1990-helps some but the big Lycomings are more like cement mixers than watches. Check to see that the early used model youre interested in has the improved mount.
One owner complained about hot starts. This problem frequently-not always-is the result of operator technique. Some engines are particularly prone to this if they are quickly shut down, then a relight is attempted before the powerplant cools completely. Fuel vaporizes in the lines and must be purged. The Continental technique of drowning the engine in boost pressure wont work on the Lycoming.
On the subject of starts, especially in cold weather, note that battery condition is important. If there’s not enough voltage, an engine start with battery should not even be attempted. Find an APU. On the other hand, the airplane does have two batteries so if one is weak, the other may still crank the engine sufficient for a start. There’s a manual battery selection switch and Mooney recommends alternating use of each battery between flights.
Owners also complain about oil on the belly, noting that the engine spews out more oil than the air/oil separator can handle. Engine oil capacity is 10 quarts but it will happily run on eight or nine. Put in the full 10 and you’ll be cleaning it off the belly after the first hour of flight.
Two owners reported recurring problems with landing gear retraction. One noted: Fortunately, the problem was getting the gear up rather than…down. It happened three times to this owner. The limit switch was replaced each time.
The other owner said it occurred three times. Retraction tests did not uncover the problem until the third event. It was traced to a faulty micro switch.
We surmise that Mooney must have had a bad batch of limit switches because this problem hasnt cropped up recently and we cant see any reason it should be limited to the TLS.