Advertising
  • News
  • FLIGHT TEST: Seabird Aviation Seeker - No place to hide

FLIGHT TEST: Seabird Aviation Seeker - No place to hide

Landing at night on a dark desert highway, with no lights other than those of a car illuminating the threshold, is not everyday flying. But routine flying is not what Seabird Aviation Jordan’s (SAJ) SB7L-360A Seeker is designed for, and Flight International is here to evaluate this unusual aircraft’s ability’s as a reconnaissance and surveillance platform.

The war in Iraq has shown the vulnerability of platoons to ambushes and convoys to roadside bombs. Helicopters can provide airborne support, but payload and time on station can be limited. Unmanned air vehicles, meanwhile, can lack the human eye’s ability to scan a wide area while still detecting the subtle changes of pattern or behaviour that can warn of an impending attack.

SEEKER SPECS

The idea of using rugged, slow short-take off and landing (STOL) aircraft for convoy protection and forward reconnaissance is not new: think of the German Storch or British Auster of Word War II.

Old school

But as aircraft have become more complex, the idea of the airborne equivalent of a Land Rover or Hummer – rugged and simple, with STOL capabilility and good low speed handling, good endurance and payload, and excellent field of view – appears to have been lost.

Seeker

The Seeker is such an aircraft, and two have been supplied to Iraqi forces for pipeline and powerline inspection and protection. The aircraft were supplied by SAJ, presently based at Amman’s Marka airport, but moving within months to a purpose-built facility at Queen Alia airport to start series production of the Seeker. Gilles Latour, SAJ deputy chief executive and de facto operational manager, has assembled a team of Jordanian designers and engineers, many of whom are European trained, with the intention of using the Seeker as the catalyst from which an independent Jordanian aerospace industry can grow.

The Seeker was designed by Seabird Aviation Australia, which still holds design authority. But SAJ has negotiated the rights to all development including supplemental type certification. In the near future, SAJ plans to obtain the complete commercial rights to the aircraft including design authority. The aircraft is certificated to US Part 23 rules and SAJ is close to obtaining European and South African approval.

The Seeker’s design is a function of its role. The forward fuselage is helicopter-like, the massive amount of Perspex providing an outstanding view forward, down and to the side. Instruments and switches are clustered in a central helicopter-style console. Downward view for ground reconnaissance dictates a high wing and, in combination with the unobstructed forward fuselage, a pusher propeller. The high-set engine means a large propeller can be used without ground clearance being an issue. The low tailboom follows naturally from the pusher propeller and means the aircraft is best suited to a tailwheel, which adds to its simplicity and ruggedness when operated from unpaved surfaces.

Rugged performer

The forward fuselage is a tubular-steel “cage” and its manufacture is presently subcontracted to India. The rest of the airframe and wing is conventional aluminium, but some fuselage and engine fairings are glassfibre. SAJ is planning to move all production to Jordan and produce panels and fairings from composites. The engine is a Lycoming O-360, derated to 168hp (125kW), using mogas (unleaded automotive gasoline) or avgas and driving a fixed two-blade propeller. SAJ is changing to a Hoffman propeller for all new production aircraft, which adds around 10kt (18km/h) to the cruise speed at the same rpm.

The basic operating weight with mission equipment fitted is 605kg (1,330lb) with a maximum take-off weight of 925kg from unpaved surfaces and 975kg from paved surfaces. Useable fuel capacity is 180litres (47USgal) in two wing tanks, giving a typical endurance of over 7h on station at low level and 70-80kt or a range of around 700km at a cruise speed of 100kt. The top speed is quoted as 133kt indicated. Sea-level ISA take-off run is 270m and landing run 200m The airframe has a limit of +3.8g and -1.5g.

The Seeker has side-by-side seating for two people, with a large equipment area behind. Rudder pedals are fixed, and the seats move. Wheel brakes are simple hydraulic-actuated discs on the main wheels operated by toe pads on top of the rudder pedals. Steering is by differential main wheel braking. A ground parking brake is fitted. Electrics are DC only and the battery charged by an engine-driven alternator.

Simple flaps are mechanically operated by a lever between the seats that has three positions; flap 0 for cruise; flap 1 for take off, approach, normal landing and slow manoeuvre flying; and flap 2 for short landing. Flight controls are conventional rod and cable to aileron, elevator and rudder. The elevator can be trimmed mechanically in flight using moving trim tabs. The aircraft can be flown in limited instrument meteorological conditions with the panel provided.

The aircraft evaluated was JY-SEE, the first Seeker ever produced, and now over 14 years old with more than 2,000h on the airframe. It was equipped with a forward-looking infrared (FLIR) sensor under the starboard front fuselage and a monitor that swivelled to be viewed by the flight observer in the right-hand seat or, if required, by the pilot in the left hand seat. SAJ is installing a Wescam MX12/15 FLIR in production aircraft, which will be able to display aircraft and target GPS positions on the observer’s screen and downlink this information, via a steerable antenna, to ground stations up to 100km (62 miles) from the aircraft. The cockpit was NVG compatible.

Development plans

SAJ chief designer Tariq Barakat says plans for further development include a pilot/observer “man-based” (rather than cabin) cooling system for desert conditions; 20g crashworthy seats; cabin armour using advanced materials more resilient than Kevlar to protect against small arms fire; and a lightweight flare dispenser for defence against manportable surface to air missiles.

The Seeker carried no offensive weapons, but there is provision for two underwing hardpoints. SAJ is looking at the possibility of fitting a ballistic recovery parachute and there is space for a lightweight dinghy to be carried in the rear of cabin. The seat adjustment would allow the crew to wear lightweight sports-type back parachutes and lifejackets if required. SAJ will also explore the possibility of fitting amphibian floats.

My safety pilot, SAJ head of flight operations Capt Muwafaq Al-Khalayleh, briefed me on our route: a 7,500ft VFR transit south from Marka, letting down to low level in the Wadi Rum area close to Aqaba. Cockpit entry was simply achieved by standing on the main wheel, sitting backwards into the seat, swivelling forward and bringing the inner leg over the central control column.

Two-piece doors

Cabin doors are in two pieces, with a lower bottom-hinged sill section and a larger top-hinged upper section. Either or both upper doors can be removed before flight, but cannot be opened in flight.

Pre-flight checks were simple to accomplish, much like in a Cessna 150, and the engine started using a key in the small overhead panel (for the full military version this will be changed to an integral switch). The engine controls are carburettor air, throttle and mixture well separated and differentiated and floor-mounted in a central location.

The aircraft was ready to taxi within 60s of strapping in. Immediately we were moving, I added some power and turned the aircraft through 360° around the inner, locked, main wheel without problem, proving the Seeker could turn around on a single-track road less than 14ft (4.2m) wide. Taxiing was straightforward and precise using dabs of differential brake and it was easy to see obstacles given the outstanding field of view forward.

Weather at Marka was 25°C (77°F), wind 100/10 and pressure 1023. Even at these low temperatures (in desert terms) there was extensive low-level turbulence from thermal activity. All-up weight at take-off was 900kg. Flap 1 was used, with the tailwheel lifting off at 40kt and the aircraft at 65kt. No adverse ground effects were noted during the take-off roll. Climb away was at 80kt, which gave approximately 700ft/min rate of climb. Flaps were raised at 80kt in the climb with little pitch change noted. Capt Al-Khalayleh says the Seeker has been demonstrated at 50°C in Iraq.

The transit allowed me to assess some basics. The aircraft was levelled at around 7,000ft, 2,400rpm and 100kt indicated. The seats were comfortable, internal vibration and noise moderate and not fatiguing and would be even better if full flying helmets are worn by the crew.

Cabin ventilation was adequate with an outside air temperature around 15°C and both cockpit and cabin door vents open, but I could see the value of a cooling system after waiting 30min on the ground ready for take-off at Marka. The shoulder seat belts were fixed to the rear bulkhead, but production Seekers are fitted with inertia belts that will improve the ability of the crew to move around and look out.

The aircraft displayed strong positive static stability, both in control force and displacement, when accelerating or decelerating from a trim speed of 100kt. The short-period response to pitch input was less than 1s and the long period (phugoid) around 15s. Lateral and directional stability were also positive to rudder input, but sideslip angles generated were limited by a small geared fin under the front lefthand fuselage. Present crosswind limit is quoted as 12kt but Capt Al-Khalayleh says he has demonstrated landing the aircraft in 38kt of crosswind.

Maximum roll rate was about 30°/s in response to a full aileron input. A wind-up turn at 100kt showed around +3.5G could be achieved with a linear stick-force/G gradient, no irregularities and no hint of any accelerated wing stall. No G meter was fitted, but SAJ says it will be standard on production versions. Spiral stability was neutral to slightly positive and any Dutch roll tendencies were immediately damped. I believe the aircraft could benefit from a simple two-axis autopilot, electric pitch trim and a shorter control column to set the pilot’s top handgrip lower. SAJ says all these modifications are to be incorporated

Straight unaccelerated stalls were assessed at 3,000ft at flap settings 0, 1 and 2. These gave stall speeds of 60kt, 55kt and 50kt respectively. Stall characteristics were docile, with moderate airframe pre-stall buffet accompanied by a stall horn and bright red warning light on the instrument console followed by a gentle nose drop to about 15° below the horizon. The stall horn/light was an enhancing feature because in turbulence the pre-stall buffet may not be so easy to recognise, especially if the pilot was looking outside at low level when manoeuvring hard.

Exceptional view

In short, the flying characteristics were much like any other conventional light two-seat aircraft with this sort of construction, but benefiting uniquely now from exceptional field of view, cabin size and ruggedness.

I was then able to evaluate the Seeker in two mission scenarios:

Low level/close-in for visual reconnaissance of moving vehicles, people and roadside objects, typically flown at 30ft and 30m stand-off distance from the object.

Medium level/stand-off for wide angle visual and sensor surveillance of vehicles or buildings, typically flown at 3,000ft and 3, 000 m stand-off distance to remain outside small arms fire.

The low level/close-in scenario was flown at 80-85kt and flap 1. Aircraft speed in relation to typical vehicle speed (of about 45kt) meant that moving road/rail targets were tracked in series of circles or clover leaf reversals. Wires were a constant danger since most followed the roads and many minor masts were lattice type with supporting side wires. But the outstanding field of view meant that spotting and avoiding wires was straightforward. The Seeker felt stable and able to sustain around 2.5-3g in a level turn without losing speed. I would have preferred higher roll rates to cope with rapid reversals for observer positioning or bank corrections when turning hard in turbulent conditions close to the ground, but this was aggressive flying at low level. It was immediately apparent that the Seeker needs upper cabin windows above the pilot/observer’s head to be able to look directly into a highly banked turn and production variants have this fitted.

Cars and camel trains were overflown at close enough proximity to read vehicle licence plates and clearly see what people were carrying. Roadsides could be reconnoitred for suspicious articles at 10-20ft and areas to the sides out to 100-200m swept visually and easily by climbing quickly to around 100ft. My opinion was that the Seeker could be flown aggressively at low level and, except for hover, do anything a helicopter could do in a close-in surveillance role and still remain safe.

Specialised job

The medium-level/stand-off scenario was flown at 70-75kt and flap 1, and various ground targets were selected using the FLIR/TV and tracked by the observer. Tracking is a specialised job for the observer given the disorientation the pilot could experience if he viewed the FLIR image as the sensor ball was unlocked from its stowed position and slewed quickly. Buildings could be auto-locked and there was no unlock in 360° of azimuth and up to around 50° of bank (the FLIR ball is biased to the observer’s side of the fuselage).

I felt a digital moving map/tactical situation display showing aircraft position and that of the ground force or convoy being protected would enhance the sensor information. SAJ is planning a complete upgrade of the Seeker’s cockpit and central console to hold a large moving map. Convoy vehicles would carry lightweight transmitters that broadcast GPS position. This could be converted into a range/bearing from the aircraft or plotted on to a moving map.

Unfortunately, SAJ could not get permission from the Royal Jordanian Armed Forces for the release of two sets of night vision goggles (NVGs). My night evaluation therefore consisted of roller and full stop landings on an unlit minor runway (roughly 15m wide) on a military training range in a desert area east of Amman. There was no moon, no natural light, and no runway centre or side reflectors, just darkness apart from the aircraft’s own taxi and landing lights and the headlights of a car positioned to define the threshold and general orientation of the runway. Landings were made both over the car and from the other direction over the opposite (but completely unlit) threshold. It was cheek-clenching, World War II Lysander stuff, but I did it, which means with the aid of NVGs and better ground illumination, others can in an operational environment.

Right stuff

The Seeker seems to be an aircraft with the right capabilities, in the right place, at the right time, and at the right price. Its ruggedness and fitness for function are, in my opinion after this short assessment, unquestioned. This conclusion is supported by a US Department of Defence team that evaluated the Seeker in the reconnaissance/surveillance role just two months earlier and reported it performed “flawlessly”, says Latour.

The price of the basic Seeker is $250,000. Fully equipped with the latest FLIR, video downlink, military upgrades and survivability enhancements the price is around $900,000. This compares with a helicopter probably costing three times as much. The Seeker also civilian applications including photographic platform, environmental survey, game spotting, mapping, tourism, police and customs patrol. Latour has assembled a qualified and determined team that knows what is required to upgrade an already capable and rugged aircraft. Through the Seeker, SAJ has the potential to create a Jordanian aerospace industry.

PETER COLLINS / MARKA, JORDAN

Related Content
Advertising
Advertising