Flight Test: Cessna 172 amphibian
- Credit: Archant
Flying or fishing, operating from land or water, an amphibian conversion makes the C172 into a flexible, fun machine
Words: Nick Bloom; Photos: Keith Wilson
If you haven’t tried landing on water, you’re missing out on one of aviation’s great experiences. One moment you’re in a flying machine, the next, it’s a boat, waves lapping against the floats... and a whole new set of rules apply.
“Don’t let the revs get over 1,200,” says Hamish, my companion, “Or you’ll damage the prop. You’ll be amazed how much wear and tear water can inflict”. We lower the water rudders (you need them to taxi) and the breeze is treating us as a sail, pushing us – in water, there’s nothing to stop it.
Before climbing aboard, I couldn’t help notice an oar clipped to one of the floats. And Hamish ships a fishing rod and kettle on trips, “In case I want to do a bit of fishing, or make tea.” It’s real Ratty and Mole stuff, not your ordinary aviating at all.
I’m having this delightful, if slightly disorientating, experience with Scotia Seaplanes, one of only two companies offering floatplane instruction in the UK. The other is Clipper Seaplanes at Rochester, run by Pete Kynsey and Anna Walker.
Scotia Seaplanes is operated from Prestwick Flight Centre in Ayrshire, on the west coast of Scotland. Their Cessna 172 is a 1969 FR172F Reims Rocket Floatplane, adapted by substituting Wipline 2350-A floats for the EDO 2440b ‘straight floats’ fitted by the factory (the number is the weight each float displaces in pounds). Each float has a castoring front wheel and a mainwheel behind the aircraft’s C of G.
The mainwheels have independent brakes for steering. All four wheels must be retracted for landing on water. The water rudders must only be lowered for taxying on water and raised at all other times (including ‘sailing’).
The aircraft has 5,500 hours, originally used as a floatplane in Finland, but it has also seen service dropping parachutists. The engine is comparatively new, with just 800 hours.
We strap on life jackets. I’m to take the left seat, which I reach after an easy climb up steps on the float and its supporting struts. The cabin seems quite high when I sit in it ? the height of the aircraft is about twelve feet. I adjust seat and straps and Hamish climbs in. Starting the 210hp six-cylinder Continental IO-360-DB is much as you would expect for a fuel-injected engine ? prime with fuel pump and throttle, then crank with the starter.
With headsets, all I hear is a low rumble and I suspect sitting high up makes it seem as though we are moving more slowly than we actually are. I taxi the Cessna across to the runway, while Hamish advises a low power setting, fifteen inches manifold pressure/1,500rpm. Steering with four wheels and differential brakes is no problem at all and the aircraft has a considerably tighter turning circle than a standard C172.
Pre-takeoff checks are pretty much as usual for a retractable, including cycling the constant-speed prop and setting the flaps to around fifteen degrees (“Four elephants,” says Hamish, depressing the switch for four seconds) and the manually-operated elevator trim to takeoff setting. Both trim and flap settings are best confirmed in this aircraft by looking at trim tab and flaps, which involves a lot of squirming.
There are (in addition to lights on the panel, blue for water, green for land) manual indicators on both floats for the undercarriage ? more squirming.
Beginning the take off, it seems strange running down the runway on four wheels. Hamish directs me to unload the front wheels with a lot of pulled yoke at first, relaxing the yoke as we gather speed. Once we get moving, the correct pitch attitude is shallow. The big engine and 76-inch prop make themselves felt and I need quite a lot of right rudder, especially when altering attitude. The takeoff run is probably around 250 metres. A gentle pull gets us off and we climb away at Hamish’s requested 85mph with me turning the trim wheel to get the yoke comfortable.
Initial climb rate is about 800fpm, the bigger engine more than offsetting the weight and drag of the floats. I raise the wheels and set trim, propeller pitch and throttle for fast cruise: 25inches, 2,500rpm,115mph. (Economy cruise is 21inches, 2,500rpm, 105mph, consuming 36lph.)
The Cessna feels big and heavy at first, but that’s probably because I’ve been flying much lighter aircraft. I feel a little robbed of view, sitting behind an instrument panel with a windscreen above it. Sensible Hamish suggests some steep turns at 1,500 feet, “For you to get the feel of the aircraft”.
Once I get accustomed to how hard you have to pull and push, I realise the 172 is actually quite a manoeuverable beast, and the view, especially through the side windows at a good bank angle, is pretty good.
The weather is spectacularly grim and we have to pick where we cross several ridges with care, because the cloud comes right down to the ground in places. We are heading for Loch Doon, where once the castle of Robert Bruce, Earl of Carrick, stood. When a dam was constructed to enlarge the loch, the castle ruins were dismantled and re-assembled on the hill, to one side.
Hamish points out abandoned open-cast coal mines, and as we near the Loch, the remains of what was once a massive Royal Flying Corps training base, including floatplane training in adapted SE5a ‘scouts’ and a rail track for training rear-seat gunners to shoot at moving targets. One remnant of the RFC days is a narrow ribbon of concrete running from the nearby road all the way down to the water and which ? providing the water level is right ? can be used as a ramp to run the C172 from water to land and vice versa.
As we ait for cameraman Keith Wilson, I’m to practice water landings and takeoffs. Hamish introduces me to the art of determining wind direction over water. From there being glassy water on one side, I make a lucky guess that side might be upwind. (Other indicators are wave direction and blown ‘white water’.)
Positioning the C172 for an approach is similar to operating at some farm strips or forced landing practice, in that there is no established circuit to worry about, but as you descend you do need to be constantly aware of the terrain, which is hilly around the loch. Hamish runs me through mnemonics, the familiar BUMPFF, PFARTS (R=water rudders; A=suitability of landing area) and WOODS (W=wind direction and strength; D=water depth). But basically I trim out for a 75mph approach with flap set, propeller pitch fully fine, mixture in, and make utterly sure we have four blue lights (plus visual indication) for wheels up and the lever between the seats up and back, for water rudders retracted.
Landing calls for a steady descent, first flaring at ten feet and then holding off just before the floats would otherwise contact the water. You then haul the yoke all the way back, which takes a fairly strong pull. The contact between floats and water feels somewhat gentle today, when the water is a little choppy ? but not much, and the water slows us fairly rapidly and then we settle.
Hamish says the floats are probably around two feet into the water. After lowering the water rudders, he has me steering around and I can see they work well, producing a respectable turning circle, although even today’s fairly light wind makes the circle noticeably egg-shaped as we drift in a crosswind. You need to be patient and keep revs low.
After making our stately way downwind, keeping that vulnerable propeller clear of the water, I turn into wind and commence takeoff. First, the pretakeoff checks, which include raising the water rudders, setting fifteen degrees of flap and setting elevator trim. Takeoff commences, like most things on the water, with full back yoke. With a large area of float submerged, full throttle gets us moving sluggishly at first, and there’s a lot of spray down there. (None of it reaches the cabin.)
Hamish says something about first pitch-up and second pitch-up, but it all feels to me like we’re accelerating, the nose rears up (so I’m steering with peripheral vision, just like a landing taildragger), and still very much in the water. After a few seconds of this, he instructs me to relax the pull to get us ‘on the step’. This is equivalent to raising the tail in a taildragger, putting the fuselage roughly parallel to the water.
The aeroplane rises in a noticeable fashion and the drag from the water lessens, but is still considerable. Nonetheless, we are definitely gathering speed. Hamish gets me to power back and alter the pitch angle both ways to demonstrate that there is a ‘sweet spot’ where the ride is just a little smoother. Then at full power again, he suggests banking might now lift one float. I twist the yoke, and sure enough the drag from below lessens and first one, then the other float separates and we are fully airborne.
This sensation of tilting to one side is pleasant and a little like balancing on a tea trolley ? a thought that will strike me again in this aeroplane. At various stages during the water takeoff I have to give medium to full right rudder to counteract spiral airflow and torque from the front end, otherwise there is a risk of the water equivalent of a groundloop.
I can see a strong crosswind from the left might overpower the rudder ? wind awareness is the key to floatplane flying. Keith and his Scotia instructor pilot Stewart haven’t arrived yet, so we’ve time for me to make several more takeoffs, circuits and landings.
Hamish points out various landmarks and I gradually get to know Loch Doon better. As is the way of these things, each landing gets a bit smoother and each takeoff, shorter. I have the feeling that it’s really not that difficult, providing you don’t encounter challenging conditions. One in particular is so-called glassy water, because without any waves you can’t see the surface. It’s vital in floatplanes not to hit the water at all nose-down.
Keith and Stewart arrive and Hamish takes over control. We water-taxi towards the ramp, slow down and at the last minute he gives high power, pulling the yoke back all the way. The nose rears up and before the aircraft has time to gather speed the front wheels mount the concrete, followed by the rear wheels. Now we’re on the hard, safely out of the water. The ramp is only a couple of feet wider than the C172’s wheels, so this is some trick.
Hamish has brought a spray can of fluorescent paint to mark the water line. “When the level drops it can expose the lip of the concrete ? I found out the hard way,” he says. “This way I’ll be able to tell if it’s safe to run onto land.” He has had plenty of practice landing here, and loves to take family, colleagues and his many flying friends on land, brew up tea and enjoy the stillness and scenery before getting back on the water and flying out.
Turning the Cessna around by hand is easier than expected, even on the narrow concrete. It’s time to get moving, because it’s just started to drizzle and low cloud is approaching. Hamish takes the controls for some touch-and-goes as near as possible to where Keith is standing – the Cessna is in the hands of a master.
Hamish’s grandfather was a clerk in the RFC, and his father ? who remembers watching Tiger Moths at Prestwick in the 1930s ? was a RAF Navigator in World War II. “I take his ‘wings’ with me when I fly,” says Hamish, who is something of a romantic. He wanted to be an RAF pilot, but failed the eyesight test. He eventually joined the RAF as an ATCO, leaving six years later as a Flight Lieutenant. Today he works for ATS as an Area Controller. Hamish learned to fly in three weeks at Inverness, “When the end of a ten-year relationship had me taking stock of my life. I realised now was the time to do what I’d always wanted, and learn to fly”. He then bought a share in a PA-28 based at Glasgow.
Each time we fly or taxi past the ramp, he talks about a submerged boulder he can see. Objects just under the water are an obvious hazard for floatplanes. (Hamish once saw what he at first took to be tree branches, but which turned out to be swimming stags.)
Hamish announces he’s going to make one landing between the boulder and the ramp, which sounds daring, but then he changes his mind and stays with clear water. “Do you want to make the final takeoff?” he asks. Gaining confidence now, I set takeoff flap and run through the pre-takeoff checks, then open the throttle, holding the yoke fully back. The engine roars, the nose rears up and we gather speed, ploughing through the water. Hamish says, “Now onto the step,” and I ease forwards then push the yoke gently and feel the aircraft begin to accelerate... and yaw left.
Immediately I push the right rudder pedal all the way over, but we’re still yawing. The shore is on the left, and to the left and on our bows is that submerged boulder. I realise there are two options: to close the throttle and rely on the water to stop us in time, or ? I am not sure if this is possible ? to lower the water rudders.
Meanwhile I’m still pushing, because as we continue to accelerate the rudder should bite. Hamish pushes on right rudder too, and whether that gives us a touch more rudder, or it’s the increased airflow, the curve changes from left to right and we surge past that submerged boulder. A few seconds later we’re safely in the air.
In cruise the Cessna on floats is, if anything, even smoother and more stable than the Cessna without them. At 25 inches manifold pressure/2,500rpm/ 115mph, the consumption is 40 lit/hr. The view, after all that steep banking over hostile (i.e. hilly with tall pine trees) terrain, seems perfectly adequate, while to begin with I found it somewhat restrictive.
This would be a good aeroplane for long distance trips ? with a fuel capacity of 197 litres, the endurance is at least four hours and thirty minutes. And there is plenty of luggage capacity in the locker behind the seats. You do have to watch the C of G position, and with the rear seats empty and nothing in the luggage locker, Hamish pumps water as ballast into a compartment at the back of both floats. The load total is critical, and the aircraft cannot carry four adults, but it can manage three with half tanks, or two adults and two children.
Hamish has flown the C172 amphibian to the Lofoten Islands in Northern Norway (within the Arctic Circle), a thirteen-hour journey in five legs, and recently flew to Lake Wolfgang, Austria.
We arrive back at Prestwick and he warns against the usual Cessna approach and landing technique, because this aircraft needs to touch down on all four wheels together, or the rear wheels only slightly ahead of the front ones. “It’s actually the same technique as for landing on glassy water,” he says. So after lowering flap and wheels, I’m to establish a descent of 200fpm, which means around fifteen inches manifold pressure and 1,500rpm, adjusting power in the early stages to establish the right descent gradient to arrive near the start of the runway.
This flying-on approach feels a little unnatural in its closing stages to this taildragger pilot, and I have to resist the temptation to flare. I probably do lift the nose slightly just before we touch down, which is all to the good, because we arrive smoothly on what feels like four wheels together. That landing a tea trolley feeling, again.
Incidentally, 200fpm is only about three feet a second, so if I did touch down at that rate of descent, I can see the air in the tyres impacting the concrete (or the give of the water in a glassy-water landing) easily absorbing the shock.
The next day, we fly in the air-to-air photoshoot with Keith in a camera plane, another Cessna 172. At Hamish’s suggestion I bring a fat cushion to sit on. Now I’m nearer to looking through a windscreen rather than up at one. We spend longer than usual in formation, because there are so many wonderful backgrounds against which to photograph this iconic amphibian.
Eventually, Keith announces himself satisfied and we fly back to Prestwick, where I’m to make my final landing. The runway in use has a significant crosswind. Hamish says “Good”, it will enable him to show me how to land a amphibian in one. “It’s the same technique on land as on water,” he says. “On water, though, if you do land with sideways drift, you risk digging in a float and even turning turtle.”
For this reason, my preferred technique in a crosswind of crabbing, then kicking straight at the last moment is out. I must oppose the crosswind by sideslipping. It’s a while since I’ve used the sideslipping method, I wonder how I’ll get on. My aim is to set up the same slow descent as before, but first I bank the aircraft into the crosswind, feeding in more and more bank until we are no longer drifting sideways.
At the same time, I am applying sufficient rudder to keep the nose lined up with the runway. With elevator set to maintain 80mph, the crossed controls increase drag and therefore the descent rate, which to begin with is 500fpm, not 200fpm as specified by Hamish. I get that sorted out by feeding in a little more power and manage to get back to 200fpm before we approach the runway. Having got everything stabilised, the landing is astonishingly smooth. We touch down on both left wheels together. Just as though this were a tea trolley, it’s stable on two aligned wheels.
So whereas in a three-wheel configuration (nosewheel or tailwheel) there’d be a squeak of rubber, in this arrival there is none. The two right wheels then gently lower and we’re utterly stable again. In no time at all we’ve taxied in, shut down and I’m climbing back down from the float to terra firma.
So how did Hamish come to operate an amphibian? “I had always thought that the Scottish landscape would be perfect for a floatplane. Then I saw an ad for shares for sale in G-DRAM, which at that time had floats, but no wheels. I met the owner and discussed it, but there was no instruction available. But, visiting a friend in Canada, I realised I could learn there, so I did. I got the UK rating in 2004 with Caledonian Seaplanes.”
And the conversion of G-DRAM to an amphibian? “I’d been thinking about the maintenance, infrastructure and other implications of only being able to operate from water. By chance I read an article on amphibious floats for 172s and with the support of trusted friends I contacted G-DRAM’s owner, Tim Crumpton, and put it to him. He agreed, we reconstituted the group and I agreed to do the STC work and financed the changeover.
“We took on two additional owners. There were complications, and when we did finally get the floats approved and fitted and all the flight testing done and the approval came through; disaster! An un-forecast gale snapped a tie-down rope and the aircraft blew over, with just one hour flown. So we lost even more time while repairs were made. The first flight was in 2006. In the two years after the repairs I was doing most of the flying, so I bought out the others and became sole owner. I got my class rating instructor’s qualification in 2008.”
And the situation today? “I’m a private owner, but also MD and owner of Scotia Seaplanes Ltd (a CAA-registered facility) which can hire the aircraft out for instruction towards a class rating.
“We charge £30 for instruction and £270 wet for the aircraft. At present, the only solo hire is to my two co-instructors, Stewart Houston and Nick Sibley. We are looking into air experience flights and trial lessons, but are busy enough without them at present as we all have full-time jobs. The aircraft flies 100-150 hours a year, about half of which is instruction. My goal has only ever been to break even, and we are not quite there yet.”
One student, whom Keith and I met on our first evening in ‘The Smoking Goat’ in Ayr, is Pauline Gallagher, who has suffered from birth with Cerebral Palsy. She is a keen promoter of Flying for the Disabled and Aerobility. Pauline has flown a hundred hours dual, five in G-DRAM, which she dearly loves and twenty minutes solo. Pauline, a beautiful, charming lady, works for British Telecom in cybercrime prevention. Hamish is keen to publicise G-DRAM and may seek a distillery or brewery to sponsor it and repaint it in their colour scheme.
Hamish has recently obtained a DA on the aircraft and is to feature it in the forthcoming Scottish Airshow. To help promote the aircraft and attract children to flying, a children’s book has been produced: Wee Dram and Captain Ham with stories by Garry Burns and illustrations by Ken Letham.
Would you like a turn in G-DRAM?
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