Airtest – Socata Tobago

And even the aircraft tested here, Socata’s TB 1 O Tobago four/ five-seater single is not exactly a brand new aeroplane but one which has been in production for nine years but at least has survived the trials and tribulations which have very nearly wiped out the American industry.

Socata is the General Aviation arm of the giant French aerospace company, Aerospatiale, manufacturers of everything from space vehicles to major components of the Airbus and ATR42 transports plus the highly successful Ecureuil, Dauphin and Puma helicopters. Socata manufactures not only the ‘TB’ series of light aircraft (plus their predecessors, the famous Rallye family) but also components for most of Aerospatiale’s other products plus the Dassault Falcon range of corporate jets.

The TB or ‘Caribbean’ family consists of five members, the fixed undercarriage TB 9 Tampico with a 160hp Lycoming 0-320 four-cylinder engine, the TB 9CS with constant speed propeller, the TB 1 O Tobago with a 180hp Lycoming 0-360 four-cylinder powerplant, constant speed propeller and increased weights and the retractable undercarriage TB 20 and TB 21 Trinidads. The normally aspirated TB 20 Trinidad’s airframe differs only in detail from the fixed undercarriage models’ but is powered by a 250hp Lycoming 0-540 six-cylinder engine, while the TB 21 Trinidad TC is powered by a turbocharged version of the same powerplant. The Tampico and Tobago first entered production in 1979, the Trinidad followed in late 1981 and the Trinidad TC in 1985.

Since then some 800 of all models have been manufactured, fixed gear versions accounting for around two-thirds of the total.

Rather than simply fly the Tobago around the usual Sydney ‘test track’ – Bankstown training area – we decided to put the aircraft to work in a role which would be more appropriate and realistic for the day to day use of its potential purchasers, businessmen who fly themselves from point to point on company matters and private pilots who use their licences for touring purposes.

Sydney (Bankstown) to Port Macquarie on the NSW mid-north coast via the light aircraft lane, Singleton and Taree was the chosen route, a distance of 204 nautical miles. There were four persons on board and the aircraft (Aerospatiale Helicopters Australia’s demonstrator, VH-TOI) was fueled up to its maximum takeoff weight of 2,535Ib (1. 150kg).

AHA’s Commercial Manager, David Griffiths was in the right hand seat and he showed me around TOI before we departed. Externally, the Tobago is a stylish aircraft with a distinctive and modern shape, while its twin upward opening ‘gullwing’ doors afford ample access to the cabin from both sides.

A baggage compartment is situated behind the rear seats and is accessible from the outside by a small and awkwardly shaped door on the port side, the shape being a function of the aircraft’s structural design. Only smallish items of baggage will fit through the door, larger suitcases and so on requiring loading from the cabin over the top of the rear seats.

The cabin itself is considerably wider than anything else in the Tobago’s class and superbly furnished, having the atmosphere of a luxury car rather than a typical light aircraft.

The instrument panel is of modular design and is divided into three sections. The pilot’s section contains the flight and navigation instruments in its main section, while below it adjacent to the control column shaft are the fuel selector, parking brake control and ignition switch.

The centre part of the panel contains engine instruments (fuel pressure, oil pressure and oil temperature gauges) plus the fuel gauges at the top and the radios stacked vertically below. These engine and fuel gauges are of the vertical read-out type and to my eyes looked a little incongruous sitting up there among all the other circular dials. Nevertheless they were well-placed and easy to read, which is more important than how they fitted in with the rest of the decor!

VH-TOI is fitted with an enlarged Trinidad-style right-hand panel module and on that were the tachometer and manifold pressure gauges (both canted towards the pilot) plus optional cylinder head temperature and exhaust gas temperature gauges.

The centre console houses the switches (which activate a light on the pilot’s panel when turned on – a useful reminder), the electric flaps switch, the engine and propeller controls and the elevator trim wheel. No cockpit-controllable rudder trim is fitted, although a ground-adjustable trim tab is.

Being six feet four inches tall, I’m a good test of seating position in aircraft, cars and anything else which requires sitting down. I’d heard stories of insufficient head room for taller people in the Tobago and its cousins and was pleasantly surprised to find that, in fact, I had a couple of spare inches between my head arid the cabin roof. With the seat all the way back my long legs fitted as well as they do in any other aircraft, while I was able to achieve a comfortable ‘hands and arms’ position with little trouble. TOI was not fitted with a seat height adjustment, but I found I wouldn’t have needed it anyway.

Starting TOl’s carburetted Lycoming engine follows standard practice, and after the normal checks we taxied to Bankstown’s runway 29R. On the ground, the Tobago exhibited positive nosewheel steering and a small turning circle.

Pre-takeoff checks revealed nothing amiss, and following clearance and setting of takeoff flap we were away. Despite the aircraft being at maximum weight and that morning being very warm at ISA+ 15, acceleration was brisk. There was little swing due to torque effect and in fact I found myself anticipating a swing which wasn’t there, necessitating a quick correction.

Lift-off was achieved at 67 KIAS following a very gentle amount of back pressure on the stick, the extremely aft-mounted all-flying horizontal tail surfaces providing powerful authority. Initial climb was about 780 feet per minute, again despite the weight and heat and the fact that in order to achieve better visibility over the nose in the climb our indicated airspeed was a few knots above the best rate speed of 73 KIAS.

This figure was substantially better than the published rate, and in fact ‘beating the book’ became a feature of the flight, Dave Griffiths explaining that the published numbers are those achievable by an aircraft several years old, Socata preferring to err on the side of conservatism. As TOI was less than 50 hours old when I flew it, Dave was not surprised to find the book figures were beaten as easily as they were. He had prepared the flight plan for this trip and had assumed 135 KTAS in his calculations, some nine knots faster than the published figure for the conditions. Owners of older, well used Tobagos have confirmed the conservative book figures, some reporting that it has taken a lot of years and flying hours to degrade the aircraft’s performance to those in the book.

My impressions of the Tobago’s handling qualities were quickly established, the overall feeling being one of greater responsiveness than other aircraft in its class, with everything harmonised nicely.

Our flight track took us over the Hawkesbury with a gradual increase in altitude to 7000ft as remaining outside controlled airspace conditions permitted. Our cruise climbs were at 100 KIAS below 5000ft and 95 KIAS between there and 7000ft.

Settling into the cruise at that height and navigating via the Singleton, Taree and Port Macquarie NDBs, there was time to relax a little and enjoy the flight and the aircraft. We were cruising at full throttle (which gave us 22 inches manifold pressure) and 2400rpm, a setting that gave us Dave’s predicted TAS of 135 knots or 250km/h. Less than an hour and a half after departing Bankstown, it was time to prepare for a landing at Port Macquarie’s uncontrolled aerodrome. Unfortunately for me, it all got a bit busy in the circuit as I hadn’t descended at a great enough rate and found myself much too high as the aircraft was turned onto base leg. Some more height had to be lost quickly at a speed close to the Vno of 128 KIAS, which meant that finals were also a bit too hot at first.

Thanks to some expert instruction from Dave, the situation was retrieved and by the time we were halfway down finals the Tobago was at the correct height and sitting on 75 KIAS with flaps down and everything under control. As one of those who likes to have his circuit ‘in the groove’ by early downwind, do the checks and then have that few seconds of free time to get his brain fully into gear before turning base, I was feeling the pressure a bit on this occasion, but the Tobago was well up to handling whatever incompetence I threw at it!

We touched down exactly 94 minutes after lifting off from Bankstown, giving us an average speed over the ground of 127. 5 knots or 236km/h. Our fuel burn worked out to average 8. 65 imp gal (39. 3 litres) per hour, allowing an endurance of nearly 4. 5 hours with full tanks and VFR reserves at the power setting we used.

A potential customer for the aircraft flew it home to Sydney, allowing me to sample the back seat comfort. This time my head was just brushing the ceiling, but I found myself with ample legroom, which for someone my height is an enormous advantage. The cabin is a massive 50 inches (1. 28m) wide across the rear seats, which completely removes the ‘sitting on each other’s lap’ feeling of many light aircraft. The cabin noise level was no better or worse than similar aircraft, a moderately raised voice being required for conversation at the high power settings used.

There is no question that the Tobago is a capable, comfortable and pleasant to fly touring aeroplane. Its interior is by far the best in its class, and its flying characteristics inspire confidence. Of course, its external appearance is a matter of personal taste, but to my eyes it would be very difficult to describe the Tobago as anything but an attractive aeroplane.

Aerospatiale Helicopters Australia is the local distributor of the type and they can offer full spares and maintenance support Australia-wide. Also, they are in a position to offer a financial package custom-made to a purchaser’s requirements through heir associated finance company, an important consideration in these days of needing to keep a close eye on the taxation situation.

VH-TOI is available for around $140,000 equipped with a King KX155 Nav/Com with Kl203 VOR/LOC indicator, King KT76A transponder, King KR87 ADF, audio, Narco ELT, rigid antennae, front seat intercom, gyros, strobe, cabin fire extinguisher, external power plug, electric clock, dual toe brakes, a central armrest on the rear bench seat, rear seat forced ventilation and de luxe furnishings.