Sunderland on Patrol - Part 1

[RobinK]

SUNDERLAND ON PATROL, NINETEEN FIFTYSOMETHING. PART 1

Flying Sunderland "boats" on maritime patrol seemed always to mean getting up at an unsociable hour. Perhaps because they cruised so leisurely, it was necessary to take off at the crack of dawn, or earlier, in order to be sure of doing anything very much before nightfall.

Having arisen however reluctantly, the immediate purpose is to satisfy the engrossing hunger that is a part of such small hours. A sympathetic system makes available a breakfast of monumental proportions at the Combined Mess.

Then to the squadron for briefing. Close-in, lights on the hard-standing reflect on the water in the pre-dawn stillness. Farther out, the water ripples in light airs coming down the channel. Ground crew are busy. Marine Section tenders fuss around the jetty, and ruffle the surface between shore and aircraft. The control launch is readying to put out.

In the operations room the navigators plot the patrol on their charts. The weather will be mostly broken cloud, some showers, wind on average 350 degrees at 15 knots, except for a front lying across the route about five hours out. They hunch over their computers - not the modern digital variety, but a device with a circular slide rule on one side and a wind-and-course triangulation gizmo on the other.

The flight engineers worry about fuel load and all-up weight; and the signallers about frequencies, Morse keys and code books. The pilots worry everybody including themselves, quiz the ground engineers, and eventually condescend to sign the maintenance release and the flight authorization.

It is not yet light as they go to the jetty, to the barge, and to the aircraft. The captain asks who has the flight rations - meaning what is in them? It will, after all, be a flight of more than twelve hours and he needs to savour the possibilities in advance.

The great white aircraft looms up in the half-light. “Watch it” calls the captain to the coxswain as the barge noses under the overhang of the wing, in his early morning irritation making an attempt to stamp his authority where it does not belong. The marine diesel bubbles briefly under power as the boat is brought to a halt with a scritch of rubber when the gunwale fender kisses the side of the aircraft. The mooring buoy streams out ahead, though the aircraft lies awkwardly askew under the competing influences of the tide and a now-rising breeze.

Aboard, the aircraft stinks. It has been tightly closed up overnight. It is redolent of salt water, mildew, verdigris, oil, fuel, sweat, old cooking and a primordial blend of liquids slopping in the bilges. Hatches quickly swing open to admit fresh air.

The navigators lug to their station on the upper deck their heavy bags of charts, logs, sextants, pencil boxes, protractors, dividers and other symbols of their art. The signallers and engineers repair variously to their stations and to other parts of the hull on their appointed pre-flight duties. One goes to the galley on the lower deck.

The Sunderland was always in two minds whether to be ship or aircraft. In New Zealand service as the Mark V, it was designed and built by a shipyard, Short Brothers and Harland of Belfast. Of semi-monocoque construciton it was a four-engined high-winged monoplane, so it was said. But it had a bridge, a wardroom, a galley, a keelson, chines, both a nautical and an aeronautical almanac (and nautical and aeronautical charts), a fog bell, an anchor and a leadline.

The galley was a grand misnomer for a cramped space where one cooked upon two Primus stoves on a bench with a sink. Hard beside was a ladder leading to the upper deck. This and the other compartments ran full across the width of the hull.

The galley had a sizeable hatch either side. Beneath each was a large container for the sea drogues. The aircraft had no sea rudder nor water brake. On the sea it was steered and the speed was controlled by a combination of asymmetric power from the engines, the air flaps, the ailerons, the air rudder, and the drogues which were launched by hand from the galley hatches. These were windsock-shaped canvas sleeves with a thin wire hawser cleated to a frame on the bulkhead. Once deployed, the force of the water flow usually meant they could not be recovered until the mooring was complete - and even then with difficulty in a strong-flowing tide. They had a spill rope attached to their tail so they might be collapsed again if need be, but it seldom worked reliably. It was better to assume that once deployed they stayed deployed, which normally meant the pilots had to call the one-shot moment with care.

Next forward of the galley was the wardroom; also a grander name than the compartment deserved. There was a bunk down each side and a fixed table with fold-down leaves in between. Naturally enough, even with the leaves propped open the surface remained out of reach of a diner of normal proportions seated on the bunks; and the height was as badly matched. To give a feeling of home, however, the table was finished in a tasteful light green. The deck was bare dural, though with worn remnants of green paint, strengthened underneath by stringers, their skeleton outline emphasised by depressions and bruises in the much-worked surface between. The walls were bare dural as well, being the thin outside skin of the aircraft. No padding, no lining, no gestures to livability; just the skin marked out by vertical constructional ribs and horizontal longerons, punctuated by tastefully rounded portholes. The wardroom became an action station on operations, for it housed the sonobuoy acoustic receiver.

Throughout the lower deck and beneath the decking, a bulkhead sealed each compartment from its neighbours. Above the decking, doorways between were fitted with swash doors extending the watertight isolation of compartment from compartment to about three feet above the deck. These could be opened but were normally dogged shut. To pass through one could open the swash doors after wrestling with the dogs or simply step over them, the latter for preference, though at some risk to the person, especially those shorter in stature. The lower deck panels had ring latches so they could be lifted to get at the bilges and dark spaces beneath, should the need arise.

Aft of the galley was the bomb room. This contained marvels of expedient engineering. In a flying boat, breaching the planing hull to provide such as bomb or torpedo doors is a design challenge. Here, the designers had chosen not to tackle the challenge head-on, but to avoid it. The weapons were carried wholly inside the hull. Bomb racks were mounted along the lower line of the wing two decks up. To load or reload in flight there was a winch, hand operated by chain, to lift the ordnance from the floor to hook up to the racks.

So far so good. There remained the problem of getting the racks outside and clear of the airframe so the weapons could be dropped. The design engineer had provided an ingenious system in which, one supposes, as each problem was solved another arose to be solved in its own way. Sequential engineering.

The racks ran out on rails beneath the wings, powered by electric winch (or if that failed, by a crank wound by hand). When the racks were retracted inside, flexible strips were drawn over the rails set into the under-surface of the wing so the airflow would remain undisturbed by the discontinuity.

But with the racks inside and needing to get outside, the fuselage walls were in the way. Very well; put a door each side. These were not ordinary doors, however. They could not be hinged outward for reasons of slipstream, nor inward for reasons of space. So they slid vertically in a frame, from high up under the wing root where the bomb racks were poised on their rails.

It was necessary to seal around these doors, otherwise the spray would come in during takeoff and landing. Therefore the mounting frames were designed to move bodily inward to break the seals, whereupon the doors could drop vertically downwards along guides in the frames. The release latch to effect this was operated electrically from the cockpit, with a local manual release for emergencies. The tensioners that sprung the frames clear, breaking the seal and giving the doors room to drop, were none other than stout rubber bungees - and the doors were similarly cushioned as they fell to the limit of their travel. The original bungee jump - eat your heart out A.J. Hackett!

Aft again was another compartment with bunks, graciously called the after crew compartment. From there the floor sloped up toward the tail and the rear gun turret, with a chute nearby for dropping flares and smoke markers. This, too, had an example of thoughtful engineering design, practical though looking slightly home-made. Should a flare become jammed in the chute and burn, the results might be serious. The safety device was a broomstick, conveniently clipped to the wall, which one could use to persuade the errant flare to depart.

Nearby there was another monument to the nature of this beast. On the starboard side near the rear external door there was a box. In it was an array of rubber stoppers in various sizes with which to plug leaks in the planing hull. Likewise it housed a number of heavy coir mats. And there were generous wads of ordinary plasticine for the same purpose (but not in bright kindergarten colours, only regulation dingy grey-green).

Turning and moving forward again there was a step to the upper level via a hinged bridge between fixed platforms on each side. These were the waist gunner's positions. Wide hatches opened to enable a hefty point-five Browning machine gun to be mounted on a pintle each side, the barrel sticking out into the airflow. It was a free-firing weapon; if the gunner forgot to screw in the safety stop he was quite likely to shoot up the wing float in the heat of the moment. It did happen.

Moving on forward we mount up a ramp and through the central box wing structure to a tiny door at the back of the crew deck. On this ramp, to the right, was a significant device. The Sunderland in RNZAF service was equipped with the ASV Mark 6C maritime radar. But with gun turrets at the nose and tail of the fuselage, and the planing hull underneath, there was no place for the antennae but the wingtips. A radome blister was therefore attached under each. That presented a further difficulty. The radar had to look down to the sea, but from each wingtip the hang of the fuselage blocked out a goodly part of the sweep. The solution was a hefty waveguide switch which transferred the radar energy from one wing to the other at the appropriate moment each scan. With the radar running it did this with a noisy clack-clack, at least loud enough to be audible above the roar of the engines, unattenuated by the thin aircraft skin.

Moving forward again (and being careful not to fall through the open hatch into the galley below) there was the engineer's desk on the right and, stepped just forward of the front wing spar, the signaller's desk on the left. The engineer faced aft watching his panel with the engine health gauges and all of the fuel gauges and supply cocks. The signaller faced forward, presiding over an array of heavy black boxes by Marconi, with mysterious dials and knobs and, under the covers, tuning devices curiously named pecking motors. Fixed to the desk was a Morse key. Though the aircraft used HF voice modes extensively, Morse procedures were a prominent and necessary part of communications. Some signaller aficionados disdained the supplied key, and fixed their own personal "bug" in its place. This was a clever semi-automated two-way switch operated between forefinger and thumb. When the lever was moved one way a weighted spring trembler produced a stream of dots, whilst for a dash the lever was moved the other way. It provided for greater Morse speed, though in turbulent conditions it could be more difficult to use without stammer than the standard key.

Above and centre was the astrodome. In the air this was a good lookout point besides being the mount for the navigational sextant. On the water the hatch and dome could be removed for egress to the top of the fuselage and the wings. At the rear edge of the hatchway was the engine starting panel, complete with priming pumps, selectors and starting booster controls. However, unless one was an eight-foot giant one could not see out of the dome or the hatch from the flight deck. There was provided, therefore, a stowable platform to stand on.

Moving forward, the navigator was on the right and the tactical navigation table on the left. The latter had a ground position indicator, a machine which projected a crossed arrow onto a chart from above, purporting to represent the aircraft's position during ASW manoeuvres. It was intended for short-range tactical use only, being an analogue device of bell cranks and pulleys which was reliable for all of a minute or so after it was set up.

On the right was the radar tent, just behind the co-pilot's seat. It had black curtains all round, which had to be closed in daylight if the operator was to make much of the screen. It was also a nice place for a kip.

Forward yet again to the pilots' seats; or the "bridge", since this was a boat. Instruments on the panel, throttles and other engine controls in between the seats, flying trims overhead, and switches placed at random all around. Between the seats and just aft of the throttle pedestal, another opening led below to the bow compartment.

On the deck to the left of the captain's seat was the standby P-type magnetic compass; and near it the bomb door and rack actuation switch. If sufficiently ham-footed it was possible to kick this switch into action with the left heel, to the sudden consternation of others, especially those in or near the bomb room.

To the right of the co-pilot's seat was the bomb sight controller. This was yet another wondrous example of analogue ingenuity. The bomb sight itself was mounted forward in the bow compartment, looking though a thick transparency just below the front gun turret. It was an angle rate device. From the ballistics of the store to be dropped and the height and speed of the drop, one could calculate how far before the target to make the release.

Working out that point in space was one thing, but to know when one had arrived at it was quite another. The bomb sight had a transparent barrel on the surface of which were etched fine black lines in a gentle spiral. The axis of the barrel was aligned fore-and-aft. When the barrel rotated the lines could be seen against the background, but because of the rotating spiral they appeared to be moving steadily rearward. Now, as anyone knows who has watched roadside poles from a moving car, when the pole is well ahead and the angle of sight is oblique, the pole appears to be moving slowly. It picks up "speed" as it approaches until it zips past and is history.

The same principle applied with the bomb sight. If the moving graticule was adjusted according to the calculated conditions of height and speed over the ground, there would be a point at which its apparent speed and the speed of passage of the target as viewed through it would coincide. That would be the release point, and the co-pilot wound in the parameters to set the graticule speed for the bomb aimer. Great in theory; somewhat more problematical in reality.

The engine controls too were unusual. Wires and pulleys were not for the throttle levers or the propeller pitch controls in the Sunderland. They worked by hydraulic action known as the exactor system, whereby there was a pipe full of fluid connecting each throttle or pitch actuator in the pedestal with the relevant receptor on each engine. Movement of a small piston at the cockpit end caused a corresponding movement by a similar piston at the other end. Very clever; but in the case of the throttles, unless one had arms the length of the average gorilla's, one could not move the cockpit levers to full power and have the seat shoulder harness done up at the same time. Man-machine interfacing was not at its best in the Sunderland.

So we move from the bridge down the steps to the bow. Here one had to bend double, but in this compartment there were many purposeful things. A hand-held fog bell, an anchor, the anchor winch - and an axe, allegedly there to cut through the anchor chain in an emergency. How it might be swung effectively in the confined space was never explained; and those who had tried found also that its blade was no match for the steel of the chain. It simply bounced off, not without risk to the shins of its wielder as it did so.

There was also a bollard for mooring. It was stowable, under the front turret. The turret itself was retractable, by hand winch mounted in the roof. Wound back, this enabled the bowman to mount the bollard and to stand in the bow to catch the buoy or release from it.

Just aft of the bow compartment, on the starboard side and down a step, was the toilet. This had a header tank which was filled with sea water. In the air the contents of the bowl were simply discharged overboard by hand pump, raw into the environment without benefit of millepore filters or other treatment. Needless to say there were rules about where it was used, and certainly not until the machine was in airborne motion as it were. Furthermore, once airborne there was no means of re-charging the tank with water, so careful economy was the rule of the day.


PART 2 NEXT

[RobinK]

SUNDERLAND ON PATROL, NINETEEN FIFTYSOMETHING. PART 2

Let us return to our crew whom we had left beginning their pre-flight checks.

The specialist aircrews go to their specialist tasks and the captain to lordly consideration of the horizon, leaving the co-pilot to do the rest. He begins in the bow, checking security and the readiness of the equipment and the state of the bilges. He should not forget to charge the toilet header tank, for he would get no thanks later in the day if he neglects that task. He also checks under the floorboards to ensure the spare drogue is safely stowed, and that there is no excess water slopping around in the bilges. Finally he checks the hand-operated portable bilge pump (this item could be critical, but mainly because the power pump driven by the auxiliary power unit in the starboard wing root was notoriously unreliable. It was susceptible to the induction of muck, of which there was usually plenty in the bilges. As it clogged up in a matter of minutes it lost its suck. The hand-operated pump was efficient, but had been designed with the working stroke on the pull not the push, which presented its own set of problems when trying to use it bent double in the bow compartment in particular).

Then aft through the wardroom to the galley, checking the swash doors are properly dogged on the way. All equipment in place and secure - the second signaller is unlimbering the rations. The copilot looks out under each wing. This is not, as some say, to prove he can count up to two, but rather to look for telltale engine oil or fuel leak stains; or inspection panels left open.

To the bomb room. Here he checks that the bomb doors are properly closed but the releases are engaged and cocked. He tests the manual overrides, re-cocks the mechanisms and then checks that the motive bungees are properly in place. He also checks out the bomb racks, not forgetting the safety pins if there is any live ordnance aboard.

Aft through the crew compartment to the sloping deck up to the tail, checking the after door and the leak stoppers nearby. Here he does lift the floorboards to check the bilges punctiliously. The problem is not that the hull is prone to leak from the sea at this point any more than anywhere else. The aircraft is waterproof underneath for obvious reasons. Less attention was paid to waterproofing it from above, however. (This could have consequences when flying in freezing conditions in rain. The flight deck could flood and the flood turn to ice, as sometimes happened in the winter during regular air bridge sorties from Wellington to the Chatham Islands at the behest of Norman Kirk, then Member for Lyttelton.)

The particular concern with the rear compartment is that it is well aft of the centre of gravity. Rainwater does tend to collect here. Any water in the after bilge will slosh further aft during takeoff and, at one kilogram per litre, could upset the balance of the aircraft beyond the authority of the flying controls to counter. It is not a good time to discover this under full power as the aircraft rears nose skyward to lift onto the “step” during the takeoff run in an attempt to get airborne well before the physics of airflow say it is time.

Then back to the tail in increasingly cramped space. Control runs free and clear, emergency broomstick in place, rear turret aligned fore-and-aft and locked. (Momentarily our co-pilot reflects with satisfaction that he did not swallow the story, as some had done, that the manufacturer finished the build of the aircraft by popping in a special last rivet in the tail, in a place which could only be seen by craning over the edge of the turret from a precarious and undignified position. The Legend of the Golden Rivet had taken in many less sceptical souls. It had resulted in much unkind hilarity on the part of the perpetrators, and inelegant embarrassment on the part of their victim, when the latter got caught surreptitiously prospecting for gold.)

The copilot again moves forward, up over the gun platforms onto the deck with the wave guide switch, checking hatches and equipment. He manoeuvres through the small door onto the flight deck and advances to the lookout hatchway. He climbs up and out.

The surface is damp with morning dew, and greasy with a residue sheen of oil, fuel and seagull shit. Overhead are the wires of the HF aerials strung from the "goalposts" just behind the hatch to the extremities of the airframe. The copilot must now walk the wings to check bits and pieces, and he knows what it must have been like to walk the plank. But that is the easy part. He must also walk the length of the top of the fuselage, which is not too bad though the footing narrows toward the rear. The difficult bit is negotiating the vertical fin to get onto the horizontal tailplane. There is neither hand hold nor foot hold. The surfaces are smooth, and slippery.

The geometry requires that to get around the leading edge of the fin he must lean outward slightly, contrary to his instincts some twelve feet or so above the moving ripple on the water, and step onto a sloping curved part of the fuselage before lifting the other foot around the fin and planting it on the upper surface of the stabilizer. Having inspected the elevator, he must then detach his attention from the balancing references around him and throw his head back to look up at the tall rudder towering high above. Finally he must retrace his steps and repeat the procedure on the other side of the fin and the other stabilizer.

For these high-wire activities the canny co-pilot never failed to keep an eye on the jokers who might lurk among an otherwise trustworthy crew. The Sunderland's wing floats were designed so that only one touched the water at once, while the other hung clear. Factors such as fuel loading - the fuel was in tanks in the wings - and wind direction defined which of the two was in the water, and the aircraft leaned over that way when at rest. But the weight of a man on a wing could turn the balance the other way, and the aircraft would roll to dip the opposite float. The actual angular change was only a few degrees, but when precariously balanced on one foot in mid-step around the fin, those few degrees were a lot if the change came unexpectedly. The sport of trying to cause the copilot to fall off the tail by rocking the aircraft in this way was frowned upon by officialdom, but was one of those things impossible to stamp out.

The pre-flight complete, the chant of the pre-starting checklist begins, with challenges and responses from throughout the aircraft on intercom. Hatches secure, fuel tanks selected, bowman ready, throttle and pitch exactors primed, vicinity clear. By this time the bowman has retrieved the mooring strop from the eyebolt on the keelson under the nose, looped a painter from the bollard through the upper cage of the buoy and taken a turn back around the bollard. Clear and ready.

Start the outer engines first, normally beginning with Number One on the port side, then Number Four. The Pratt and Whitney R1830-90D Twin Wasps turn over, cough and splutter into life. Their idling speed is set much lower than in the case of land-plane installations. This runs against the grain of conventional airmanship, because aero engines are fine tools which prefer operating under load.

One is taught to avoid idling piston engines unnecessarily on the ground at other than the minimum rpm defined by their maker, which is usually at a throttle setting above the minimum stop. But even at the reduced engine idle speed in a Sunderland the propellers bite well enough to run the aircraft up against the buoy and tension the mooring. Consequently the engines can be hard to start, because the throttles cannot be cracked too far open for fear of a sudden burst of power ripping the aircraft from its moorings, or even the moorings from the sea floor. Hence the elaboration of the spark boost and priming pump controls in the lookout panel. And at the unusually low idling speed, sometimes the engines simply die as the spark plugs oil up. Naturally enough this tends to happen when they are most needed; it is one of the rules of aviation, written by Sod as his Law.

With the two engines ticking over the mooring is slipped before the inners are started. This sometimes requires smart work in confined roadsteads. Asymmetric power applied to the inners will help turn the aircraft but the turning moment is not great and the power needed also accelerates the aircraft forward. The outers have a greater turning moment, and so can induce a turn without so much power and forward impulse. Unless careful, in all of this it may be necessary to stretch yet another land-plane rule by running engines up to highish power as soon as they fire, well before they are warmed up, simply in order to get the water turn going, or to control it.

The aircraft now noses out into the channel as the mooring crew tidies away the ropes and other equipment, and extends the front turret into place. In known waters the leadline is not needed, though the crew has passed interminable examinations involving arcane calls such as "by the mark five" or "by the deep six", not to mention the meaning of a piece of leather with a hole in it. They also need to know the difference between under way and making way on the water; what one, two or three blasts on a siren may mean; how to recognise a port-hand marker from a starboard-hand marker; and who has the right of way when a flying boat and a yacht are on converging courses.

Another thing one cannot do in a flying boat is run up the engines to test whilst tethered to the buoy. The mooring gear wouldn't stand it. Since there are no brakes once slipped from the buoy, it must be done on the move. Nor can it be done one engine at a time, because the aircraft would simply pirouette and probably break off a float. But it cannot be done all four at a time either, because the machine would get airborne. So it is done two at a time, symmetrically. Moreover, because it is not a short procedure much of the available takeoff run will be consumed in the process. This requires some forethought. If, for example, one were to run up a pair of engines heading downwind, and the other pair into wind, one would then be at the wrong end of the seaway for takeoff. So there is a lot of manoeuvring to be done between slipping the buoy and the takeoff and, though it might look aimless to the observer, it all has a purpose.

Our crew accomplishes all this, and is ready for takeoff. The trims are set - elevator two-and-a-half divisions nose up, rudder one-and-a-half divisions right. Mixtures full rich. Pitch controls full fine. Fuel tanks "twos and fives selected"; this from the engineer. Flaps one-third.

Off we go, steering with asymmetric throttle initially; there is no other way. The seat shoulder harness is necessarily discarded, for the reason mentioned above. As speed is gathered the rudder begins to gain effect, and the throttles can be advanced in unison to flat chat. Both hands on the yoke; the copilot now holding the throttles. The downside wing can be picked up (and better be, lest the float digs in). The nose comes up sharply initially and spray breaks over the front, but it lowers again as the hull lurches up onto the "step" and planes along with sharply reduced water drag. The spray plume is now left behind but is still spectacular.

Folklore has it that seaplanes sometimes fail to get up on the step. The writer experienced this only once in over 2,500 flying hours in Sunderlands. It was in Manila Bay, in the middle of the night, with a significant cross wind from the right, hot as hell, and laden with technical crew and their duty-free goodies after a long SEATO exercise based in Singapore. We started the run, and laboured on and on with the nose locked high, well short of reaching the planing step. The engines did their best, but it was a lost cause. We closed the throttles as the end of the seaway loomed up, to find that the control launch had kept handy pace with us throughout the run. We taxied back to try again. This time we took advantage of the width of the marked seaway and angled across it more into the wind. We were also fractionally lighter by the amount of the fuel we had burned in the first attempt. We got airborne, just, and then had an interminable time clawing for altitude.

No doubt this could be taken to add to the legend that "boats" sometimes refused to climb up onto the step. But I have to disappoint those who might see an ineffable mystery in it. The problem in our case was much more ordinary and certainly more explainable than dancing to Neptune's cranky moods. It was a matter of power. Without brakes or wheeled contact with a firm runway to help keep the beast from careening off the marked seaway, we had not been able to get enough way on to give rudder control to hold the direction against the wind. Unable to advance the left outer throttle in the crosswind, we were trying to beat the air into submission using only three-quarters of the available power. The air won. (As an aside, the P & W Twin Wasps each delivered about 1,200 horsepower flat out; 4,800 hp in all for the four. For the sake of perspective, each of the Allison turbine engines in the C130 Hercules delivers about as much as the four Twin Wasps combined.)

There is another legend, to the effect that once on the step some conditions of calm water could cause the hull to stick to the water – capricious Neptune again. This never happened to me, nor to any others I knew, in a Sunderland. Takeoff runs might be longer in glassy calm conditions, but only because there was no wind, not because the hull sucked.

While we are about straightening the record, there is this. Flying boats and their smaller cousins seaplanes do not provide limitless opportunities of using the most available landing surfaces in the world. They are, in fact, very limited in that regard. They need sheltered water. They need boats and barges to tend them. There could be no such thing as a convenient terminal air bridge for passengers to board them. And husbanding them and their engines against the corrosive ravages of salt water on high-technology alloyed metals is a costly business.

But their biggest enemy is the nature of the surface they are designed to operate from. The sea moves, sometimes in big waves and swells. The problem is that water is incompressible. If one hits water hard in the wrong attitude it is not the water that gives, it's what hits it, as anyone who has belly-flopped off the high board will know.

Landing a flying boat in high seas has obvious risks. But taking it off in such conditions can present a greater peril. Riding the swells at rest may be possible, if disconcerting. But at some point in a takeoff run the aircraft will crest a swell and be thrown off the top at less than flying speed under full engine power. One thing is then inevitable. Unable to fly, the machine will hit the face of the next swell, or the next after that. Then other things will happen. If the speed is not high enough to permit some kind of aerodynamic control, the aircraft will likely hit the water in a skewed attitude and break up or roll over on impact. Or, if directional and lateral control is maintained and the aircraft hits straight on, it will either dig the nose in and drive under, or be thrown off again to repeat the process in a porpoising action until that result - or the alternative wing-down cartwheel - is finally achieved. Neptune will feed; or if not he then the sharks, and feeding passengers to the sharks would not be an image in the interests of the airline business.

PART 3 NEXT

[RobinK]

SUNDERLAND ON PATROL, NINETEEN FIFTYSOMETHING. PART 3

Our Sunderland has finally lifted off from its base into its other element. After some minutes it reaches the assigned cruising altitude, usually no more than 5,000 feet, and settles down into level flight. The crew sets economical cruising power, mixture auto lean. This can result in another contradiction between theory and practice. The most economical speed in an aircraft is, among other things, a function of all-up weight. At higher weights the best speed is higher than at lower weights. In slow-flying low-altitude petrol-engined propeller aircraft, the relative change as fuel is burned can be quite significant. In some cases, however, of which the Sunderland was one, the maximum power available in the economy range could not reach the best airspeed at the higher weights. There was no trade-off; moving the mixture levers to richer settings in order to apply higher power to maintain the best speed simply used disproportionately more fuel. Sunderland crews were therefore inured to the indignity of wallowing through the air at the speed of a stately airborne galleon - about 112 knots - in lean engine settings at the beginning of a sortie when the best speed was unachievably in excess of 130 knots. At some point in the flight, usually hours out, the best speed would have reduced as the weight reduced, and at the same time the fixed power setting would be able to drive the lighter aircraft slightly faster. At this point of happy coincidence the power could finally be reduced.

The crew proceeds, looking forward to that moment. The flight is routine. The ocean is large. Most crew members fight off boredom, except for the second signaller slaving in the galley, for whom the opportunity of boredom would be a relief.

The ennui is punctuated from time to time by radar contacts which have to be investigated - ships, yachts, floating debris, changes in the surface texture of the sea - until the radar goes "down". Quite outside the rules, the radar man - a signaller - figures he can fix it. There is a blown resistor, he thinks. (The ASV Mark 6C radar was an adaptation of the H2S bombing system developed by the RAF during the Second World War to enable navigation and blind bombing over Germany. It was an agglomeration of thermionic valves, switches and resistors. No transistors nor integrated circuit boards - indeed, our crew is operating at a time when one of the things coveted as a purchase on overseas trips was an ordinary transistor radio, then a modern marvel. Before mass production, however, the price was still considerable and seldom within the range of the parsimonious duty-free allowances of the day.)

Our signaller elbows the galley man aside, and with spoons heated in the flame of the Primus stoves manages to unsolder the offending resistor and replace it. It works.

But how to mollify the holder of the inventory of spoons for their ruin in the process? Easy. One of the advantages of flying boats was the marvellous means they provided for inventory adjustment: "... it slipped from my grasp, Sir, and went into the tide ..." To give the proposition some kind of veracity the event was usually underlined at the time by a comment like "...*#@%, Captain, I just dropped the spanner ..." as the aircraft taxied up the channel to its moorings. Far be it from the writer to imply that there were dishonest aircrew who acquired private toolkits by this means, for it was not the case. Nonetheless, things did get lost. And if all of the tales are to be believed, there is a carpet of tools, cutlery and other paraphernalia bearing the Government arrow to be found on the floor of the harbour bases at Hobsonville and at Laucala Bay in Suva.

With the radar back in operation the patrol continues. The navigator wants to "shoot the sun" with his sextant. This could induce an argument. One of the problems with astro-navigation with a hand-held sextant is the stability of the platform. Because of this the aeronautical sextant shoots the heavenly body repetitively over a period of about two minutes, and averages the shots. The precision will depend upon how accurately the aircraft is held straight and level for the duration of the shot. Some pilots were convinced they could do this better than the autopilot - and in a Sunderland it could well have been true - but most navigators were convinced they could not. Hence the argument. And hence the recriminations when the shot failed to reduce to a useful answer.

There were other occasional tensions among crew categories. Another means available to navigators to navigate was to measure the wind regularly in order to calculate its effects on the path of the aircraft over the sea. The methods were generally only available at low altitudes. Today such techniques are irrelevant by virtue of inertial or other high-technology navigation systems; but then we all relied upon hand-cranked methods and the sweat of flesh-and-blood navigators.

Several options were available. The simplest was to apply a navigating eye to the drift sight, with its graticule of parallel lines which could be aligned to track the whitecaps below to read off the angle of drift on the bezel. Another was to throw out a smoke float and track it from the rear turret to obtain the angle of drift. A third was the three-course wind. This involved flying accurately on course for a period, then on a sixty degree diverging course for a similar period, and finally on a sixty degree converging course. The drift effects would be averaged and an accurate wind calculated. The problem was that it disturbed the even tenor of the flight. Boredom can breed laziness, and pilots resented the chore. If the radar man called a contact during the evolution, causing it to be disrupted, the signallers would also go down in the black books of the navigator.

These were not the only sources of sometime testiness. Boundaries of responsibility were to be jealously protected. The geometry of the flight deck was such that the navigator sat in line with the propellers. If their RPMs were not properly synchronised there developed an annoying asynchronous beat. The distraction was more marked where the navigator sat than where the pilots sat. The Sunderland had no modern concession such as an engine speed interlock which kept matters in synch. It was done by hand, using minute adjustments to the pitch levers whilst looking through the plane of the inner propeller to the outer, and arranging that the strobing shadow of the one as seen through the other was stationary. That was fine for each of the pairs of the engines per wing, but it could not be used to match the pairs one to the other. Hence there tended to be a lot of fiddling with the pitch levers, which were low and aft on the pedestal between the pilots. Surreptitious navigator hands have been known to creep forward to add to the fiddling.

The remedy to contain this gross breach of demarcation was also known. The pilot, should he wish to do so, could resort to waiting for the intrusion. He could then casually allow his hand to drop between the seats. The touch of hands was usually enough to make the point. In particularly persistent cases the cure could be given sharp emphasis if the hand of the pilot held a lighted cigarette; "I'm terribly sorry, navigator, did I burn you? I didn't know you were there!"

Navigators also had their gripes about pilots. Some pilots never fathomed the navigational arts, and mistrusted them from a position of ignorance. Some had themselves been navigators now "re-treaded" as pilots, and mistrusted other navigators from a position of knowledge. Whatever, navigators resented having pilots lean across the navigation table poring over the charts and calculations in detail and asking why this, why that? Some navigators not only resented it, but were driven to fury by it. Again there was a range of remedy, starting with studied ignore and graduating up through a polite request to desist, to a direct demand to bugger off. But by far the most drastic remedy known to the writer - by unverified repute only, for he was not involved – is said to have occurred during a tense flight at night in bad weather. The pilot had got out of his seat and had persisted in craning over the navigator, watching him closely. The pilot's hand was spread palm-down on the plotting table. With a movement so fast to deceive the eye in the dark, the hand was pinned to the table by the points of the navigator's dividers. Whether this story was true or not scarcely mattered. For young pilots to whom it was told the message was clear - do not mess with the navigator.

Another interlude giving meaning to life is mealtime. The signaller has been slaving away at the Primuses (or should that be Primi? Let's settle for “the signaller is slaving away at the Primus and has the other one going as well”).

There is a kind of inversion of the law of diminishing returns in using such primitive equipment. It is surprising how much it concentrates attention on producing basic quality, as distinct from producing mere fripperies in the hope of disguising poor quality by dressing it up. So it was with the cuisine aboard Sunderlands. Delicious, nutricious and generous, its quality transcended the nature of the equipment used to produce it.

Even where embellishments above the basics were available, the result did not always rise to the sum of the parts. Graham Kerr (pronounced "Care"), later to achieve fame as the Galloping Gourmet with his own TV cook show, was at one time the Air Force's catering officer. He showed often enough that the primitive equipment was no barrier to producing cordon-bleu class meals. He never quite understood, however, that at three o'clock in the morning on a black night over the Pacific Ocean, crews preferred steak, eggs and chips over his culinary artistry.

As the sortie approaches its end the activity rate rises. From the wild free wastes of the ocean, the aircraft noses back toward civilisation. The crew is tired, but digs down to find concentration. There are air traffic rules and even air traffic; and there are chores to be done. Finally, at some point it will be necessary to bring this thing back safely to the surface.

It is getting dark. The flarepath is laid out, but it is not the double line of bright lights of a land runway. The control launch has laid a single line of small buoys, each with a pathetically dim battery-powered light on the top. There are only five or so of them, spread out over the length of the seaway, with an additional one at each end displaced to show the opening and closing gates. Everywhere else there is blackness - there is nothing as black as the sea in the dark.

How does one alight in such conditions? During the day the routine is much as for landplanes - an approach at the right speeds and angle, followed by a judged round-out and settling onto the water. At night - or in smooth water conditions in daylight - the surface cannot be seen reliably. One therefore sets up a rate of descent on the instruments - about 200 to 300 feet per minute - and aims just past the opening gate, and waits. The aircraft flops on, lurches, not infrequently leaves the water again, and finally runs true on the surface. One does not close the throttles at the first touch, however, but waits for the second. If in obedience to the rules of Isaac Newton the machine has lifted clear of the water at the first touch unbeknown to the pilot, it might not take kindly to the return if unpowered. So the engine power is left on just in case, and on the second lurch is cut back.

On this occasion the captain has given the copilot a challenge. He called "engine failure" on the port outer as the aircraft approached the base, and cut that engine dead. The copilot feathered the propeller and cleaned up for an asymmetric approach. He is obliged to use rudder to counter the yaw, and aileron to hold up the wing - both of these demands requiring not a little strength, for the Sunderland had no refinements such as power assisted controls.

On the approach he sets the flaps. The Sunderland's Fowler flaps were enormous, and the full extension was used only for "sailing" the aircraft on the water. The normal settings were one-third extension for takeoff and two-thirds extension for landing. A lack of design refinement showed here too, however. The flap actuator was electrical, controlled by a switch on the instrument panel. It was not simply a matter of demanding a flap setting and getting it; the pilot had to operate the switch to cause the flaps to run out, then to cancel the switch when they reached the desired position.

Our copilot goes for one-third flap at the appropriate moment, and remembers to stop the travel at one third. Later in the approach he goes for the two-thirds setting but is distracted by the need to maintain rate of descent and direction with the heavy controls and the engine out. The extra drag requires extra power on the three working engines. More rudder, more aileron. It is becoming a bit of a struggle, and the copilot complains. The captain remarks without sympathy that he will find out why in a minute, as the aircraft approaches touchdown. It splashes on, hard, and bounces. The second bounce is almost as hard, and the copilot delays throttle closure until the third contact. By that time he realises his mistake - the flap has run out to full, and acted like a sail as intended. The aircraft is down safely, but he can do nothing to soften the remark of the captain that he is a bloody fool, because it is true.

The captain chooses to emphasise his point by calling on intercom "Practice broken float, broken float, starboard, starboard - GO!" The lookout undogs the astro hatch and launches himself through, trailing a rope which is ready to hand and attached at its inner end to a structural fixture. Other crew members drop everything and follow. The lookout races to the tip of the starboard wing; the rest come after him, using the rope to steady their progress. The idea is that if the port float (in this case) was broken the crew would get out there in time to weigh the other wing down and prevent the aircraft turning turtle.

With the crew recovered inboard again, the aircraft taxies in past the lead lights and channel markers. The lookout uses the Aldis lamp from the hatch to find the mooring buoy. The tide is running full rip, the wind is in the opposite direction, the channel is narrow. Do we approach into wind and down tide, or into tide and downwind? A vexing compromise; on the one hand the directional control will be easier but the speed of the waterborne approach will be high, and on the other hand directional control will be more difficult downwind, but the rate of approach will be gentler into the tide. It is a familiar conundrum, often argued about but seldom soluble by rote. The pilot opts for down tide, into wind, with the flaps properly used at full extension this time.

The aircraft is controllable direction-wise, but is being carried fast by the tide. The water drogues are no use; indeed to deploy them would only add to the speed problem. The bowman catches the cage of the buoy with the painter, and loops it to the bollard. Wisely, the pilot does not yet cut the engines just in case. The aircraft carries forward in the tide, the mooring tensions and the rope slips off the bollard with a twang. Go around.

This time the approach is downwind, into tide. The drogues are deployed. The flaps are retracted; no point in adding their effect to the tailwind. The air rudder and the ailerons can still help hold direction, but are used in the reverse sense with the wind behind. The approach is more sedate, though less stable, and is successful.

The engines dead, the copilot reflects while the crew tidies to shipshape. Airmanship is a matter of alertness and informed choices. Though it is impossible to be right all of the time - and on this mooring his judgement is not in question - the consequences of wrong choices can be serious. The trick is to minimise them by good procedure and teamwork. For example, he knew that the bowman would not have looped the rope too securely over the bollard on the first approach, and would have stood clear and allowed it to slip when it became obvious the strain was higher than it should be. Too secure and the line might simply have snapped, but there had been cases where it did not and the bollard was ripped out of its mountings. Equally there had been cases where a bowman was hurt by flailing rope ends, or had had his leg caught and broken between rope and aircraft as the assembly tensioned. And he - the pilot - on this occasion had allowed for the possibility of the unexpected and had positioned himself for it by not shutting down the engines when the buoy was initially hooked.

Apart from the mistake with the flaps on approach it had all had gone well, done by well-trained people who knew their business, and what the air and the sea could do to them if they dropped their guard. The banter, the rivalries, the tautness between the aircrew professions faded to nothing in the face of the need for teamwork when all would sink or swim together - and indeed, they reinforced it. Operating a Sunderland was not easy, but it was fun, and rewarding.

Our crew now ashore and on their way home has had a working day of about fifteen hours, twelve of them airborne. Today, people think little of flying from Auckland to Los Angeles in less than that time. Forty years ago, however, our Sunderland would not have made that distance - indeed, departing from Hobsonville on that route and with only twelve hours' fuel it would have fallen into the sea off Samoa. Times change.


END

[Dave Homewood]

Simply fantastic. Thanks so much for taking the time to write this Robin. It really draws the reader into the world of the Sunderland. Brillliant.

[turboNZ]

Superb writing !!!

Loved reading about how the Sunderland was operated.

Thanks very much !

[flyjoe180]

Great stuff, the Sunderland sure sounds like it was a hard machine to operate and maintain! There must be thousands of tool pieces on the Waitemeta Harbour sea bed.

[lesterpk]

Great read. I was fortunate enough to have a look around inside the MOTAT Sunderland one day when I was there. A crew of us from the air force researched and applied the markings to it after the MOTAT people last gave it a coat of paint. About 1996 if my memory is any good.
Roomy as inside, it seemed to go on forever.