APEM — the letters in the company’s name originally stood for Aquatic Pollution and Environmental Management — was founded in 1987. Over the past two years, growth has approached a staggering fifty per cent per annum, the company now employing 140 people spread across seven sites in Manchester, Oxford, Dorset, Cambridge, Edinburgh, Chester and Cardiff. It owns five aircraft and nine boats, has a fleet of thirteen survey vehicles and operates several accredited laboratories.

From the early days, water quality and fisheries surveys were APEM’s stock-in trade and the typical modus operandi was for a pair of surveyors to walk the banks of a river, taking measurements and notes as they went. The aviation connection began in 2001 when APEM, working with the Eden River Trust, undertook an aerial habitat survey. The advantages of aerial mapping were obvious, but so were the costs of hiring an aeroplane and working with companies more used to straightforward photography and mapping. “We found that most firms were either not interested in working with us to develop new specialised aerial photography based monitoring techniques or, more commonly, the quality of the final outputs was just not good enough for the purposes we intended,” company founder and present-day MD Dr Keith Hendry says in the company history posted to mark APEM’s 25th anniversary. “After several failed attempts at chartering aircraft… we decided to do the APEM thing. We bought our own aircraft and employed a full-time professional pilot so that we could control the process from start to finish. This maximised the quality of data generated and above all ensured the safety of our staff.”

There is, of course, a lot more to surveying a river than simply flying over and taking pictures. Hawarden-based remote sensing specialist Dave Cambell says, “Anyone can go and take images — but the trick is analysing them”. APEM’s first aircraft, a Cessna 172, was fitted with a 17mp Trak’Air digital survey camera that could, from normal operating altitude, resolve objects down to 3cm in diameter:enough to distinguish types of gravel suitable for salmon spawning. This covered, quite literally, part of the picture but more information was needed if the aerial survey was to be of more use.

APEM engaged an academic from Durham University to develop what became the company’s Fluvial Information System. Vital to this is the technique for measuring depth, which is based on red channel attenuation — the way that red light is blocked by water. “With FIS, we are able to cover fifty to sixty kilometres of river a day and get the job done with much the same total cost as a walk-over survey that typically covers four kilometres a day and obviously takes much longer to complete.”

The company branched out into offshore bird surveys when interest in alternative energy sources, in the form of wind farms, took off in 2008-2009. Government regulations stipulate a two-year baseline survey before construction, and monitoring during construction and operation, amounting to a total period of five years.

“Prior to APEM’s involvement, it used to be done in one of two ways,” says Dave. “Either they used a boat as a bird counting platform — and it had to be a big one, to give sufficient elevation — or they put a couple of ornithologists, kitted out with binoculars, in the back of an aeroplane.”

Pause for a moment and think of the effect of being bumped around for hours on end in the back of an aircraft while trying to identify and count tiny specks on the surface as everything speeds by at 120 knots. Good reason to throw up all over the place and fair excuse for the count being pretty approximate, wouldn’t you say? The boat-based survey might have been a little more precise, but the cost alone of providing a large enough craft ran into the tens of thousands. “Direct observation from the aeroplane was cheaper, but the survey had to be flown at 250ft to allow the birds to be identified,” adds Dave. “As wind turbines are taller than this, the technique is no use post-construction.”

Digital cameras had now progressed to the point that 2/3cm resolution was possible from an aircraft flying at the 1,000 to 1,300ft minimum altitude required to clear the typical offshore turbine installation. This allowed seabird species to be identified in post-flight analysis of the imagery, as well as precise counts. No surprise then that APEM’s aerial digital imaging technique has won one contract after another.

Based alongside Airbus

The remote sensing part of the business relocated from Liverpool to Airbus-operated Hawarden Airport near Chester at the beginning of 2011. This move provided APEM with a hangar dedicated to its survey aircraft and an office block to house both the operations and technical staff, and some of the remote sensing consultants and analysts.

Rather as a botanist counts species within a sample area defined by a frame, APEM’s survey cameras record images from a small percentage of the total survey area, which is crossed repeatedly in a series of ‘transects’ 0.5km apart. This calls for some very precise hand-flying (autopilots just cannot deliver the required precision) over periods of up to five hours. Some of the survey areas off the coast of Scotland are up 120 miles offshore, so there may be hours of transit time involved in getting to and from the survey area.

The company continues to operate the Islander it bought in 2010, its big, boxy cabin accommodating the largest survey cameras and associated data capture equipment. More recent additions to the fleet are three P68s, the Observer model offering a helicopter view at the expense of solar heating making the cabin rather warm in sunny weather. Having sold the original C172, APEM recently bought a replacement, using it for general transport, training and the odd bit of low-cost inland survey work.

While the fleet is relatively small, flight operations are carried out on a highly professional basis, as Pilot was able to see during a visit in August. Due to the nature of the work, safety is given high priority. An operational review has just been completed and it is apparent that there is a ‘no compromise’ approach, going all the way to the top of the company, and a willingness to spend money on the latest and best equipment.

Currently, four full-time pilots and three part-timers carry out all the flying duties — but this will change when, under new Chief Pilot Tom Carville’s guidance, APEM’s cadet training scheme is launched. “We have 100 prospective candidates, among them some of our camera operators. I’d like to be able to offer some career progression to those who want to do it, and have the necessary ability.”

Tom comes from an executive aviation background and is working on longer term plans to extend APEM’s aviation activity in that direction. Some of the foundations are already in place — “Our AOC is written around jet operations,” he says.

It is all too rare today to find a company making a decent profit from aerial work. Given APEM’s success in the environment business, the professionalism that extends throughout its varied activities and its remarkable ‘can-do’ ethos, it seems to be set to make quite an impact in the worlds of professional flight training and executive aviation.

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