P210,Cessna’s High Flying Single

At least one authoritative US aviation magazine has already dubbed the Pressurised Centurion Plane of the Year – and it’s a safe bet the plaudits won’t stop there.

The price in Australia is higher than some twins now marketed in this country. The aircraft evaluated in this test was marked at $110,000A, on the Australian register with a number of options fitted.

For that money the buyer can expect an aircraft embodying ample power, comfort, speed and flexibility. And he gets it in the P 210, perhaps the heaviest and most powerful single in the Western world’s inventory.

When Cessna implemented their design philosophy, the basic 210 air-frame was retained. However, to accommodate the 3. 35psi cabin differential under pressurisation, the windows were trimmed down, a complex locking system built into the only door (left side), a mandatory right-side escape hatch was fitted, and a pressure vessel plus rear bulkhead was installed.

The total weight penalty amounted to about 200Ib, enough muscle to hold in about 1. 5 tonnes of internal pressure. Maximum gross on take-off escalated to 4000Ib in beefing up the P Centurion.

What emerged from the Wichita plant was the last word in sophisticated singles – retractable gear, turbo- charged and massive 310hp Teledyne- Continental TS-10-520-P engine, pressurised from the turbo’s compressor stage, really comfortable and typical 210 series seating for medium- long hauls, and retaining all the enviable Cessna-engineered flexibility of operation.

Cessna went in hard on their advertising. They called the new beast, as mentioned earlier, the most efficient high-altitude aircraft ever designed.

The justification for this statement was spelt out; with one engine, the Pressurised 210 can operate at 23,000ft whilst maintaining a 12,000ft cabin atmosphere. At 20,000ft it operates at 226 mph for 938 miles (statute) carrying more than 1670Ib – all at 77 sea miles per gallon (US).

This says Cessna, represents the highest efficiency rating of any pressurised aircraft being built.

Apart from sealing the airframe to hold pressure from within, Wichita has quietened the 210 design down to an admirably tolerable decibel level inside the cabin. Even the windscreen has come in for additional depth.

With a TBO of 1500 hours, the Pressurised Centurion is obviously not every man’s choice when it comes to budgeting. But as a long-term invest­ment, it will pay handsome dividends, being way ahead of its time in many respects and able to virtually choose what weather it flies in.

Rex Aviation, Australia’s Cessna dis­ tributor, provided a new P 210 for evaluation; it still bore its US registra­tion of N7587P. With the aircraft for the test came Rex’s Frank Bonnor.

A walk around the test aircraft brought to light the points already noted, plus extra rows of rivers which seemed to enhance the P 210’s almost man-of-war solidity and indestructibili­ty.

On rivets; it appears Cessnas will always – unless some future engineer­ ing process accompanied by inexpen­sive is evolved – sport those lines of rivets.

Tests have already shown an insignifi­cant increase in speed on a “smooth­ skin” Cessna wind-tunnel model, bear­ ing out the claim that smooth-skinning a Cessna is really an ineffective and non-cost/efficient exercise.

Standard construction, apart from the pressure vessel, was apparent in the test aircraft, with the usual Frise-type ailerons, single-slot flaps, typical hard­ to-hoId in ground configuration elevator down-spring, and aileron­ rudder interconnect.

Notes from the manual before start­ up showed some interesting figures: Max weight for take-off 4000Ib lan­ding, 3800Ib.

The fuel-Teledyne Con­tinental six-cylinder engine can hold 310hp at 38in for five minutes without engine damage, maximum continuous being given as 285hp at 37/2600, driving a massive 80in McCauley triblader.

Vne is listed at 200kts IAS, Vno 167kts IAS, Va at 4000Ib is given at 130kts IAS.

Flap operation to 10 degrees can be initiated at 150 IAS, and 30 degrees can be lowered at 115kts IAS. Vol is 140kts IAS, with gear extension possible at a handsome 200kts IAS thanks to the P 210’s spindly legs. The aircraft is stress­ +3. 8G and -1. 52G.

The test aircraft, with three p.o. b. and an estimated 55 galls US of fuel in the 90 galls US tanks, was well below max take-off weight. About 874Ib was calculated as the margin.

The panel on board N7587P was, in Cessna’s words, human-engineered. The only snag in an otherwise eminent­ ly easy-scan pattern was the placement of power and rpm gauges to the right of a central comm-nav/comm and auto­ pilot bank which gave rise to slight parallax error during the evaluation sortie.

Visibility and seating got high marks in the test aircraft. As in other Cessna 210 variants, back-seat passengers have ample room to stretch out. Their baggage is stowed in an unpressurised after compartment taking up to 200Ib.

Start drill is standard procedure for a fuel-injected motor full rich, high rpm set, throttle fully closed initially, aux. fuel pump on and advance throttle to register between 50-60 lbs/hr fuel flow.

Throttle back smartly to IDLE and aux. pump off.

Ignition on, and advance throttle un­ til the engine fires.

Ground ride and handling is remarkable for its lack of surprises, and even during the run-up, it was patently ob­vious that this is a quiet aircraft.

The right trim was wound on before take-off and after the run-up, to help ab­sorb some of the 310hp engine’s torque application to the prop. The P 210 manual recommends 10 degrees of flap for normal take-off, pre-selected on the standard Cessna flap toggle.

On the take-off run’s initial stage, the test aircraft tended to wander left despite the rudder trim application. This was easily corrected with slight braking until the rudder became effective.

Rotate speed came up remarkably quickly in an exhilarating acceleration to 60 knots IAS. The nose wheel was eased off gently prior to Vr, on the manual’s recommendation.

During the take-off run the 38/2700 readings were monitored and power was brought back slightly to avoid over­ boost.

Book distance to wheels off was 1300ft but this was bettered handsomely in view of the test aircraft’s weight.

Initial climb registered over 1100fpm – ISA climb rate is 930fpm at max gross. Gear and flaps in and up, a steady climb of 1100fpm showed at 100kts IAS in an outside air temperature at 18C Set­tings at that stage were recorded at 32/2500, fuel flow 14. 5 US galls/hr.

(Manual figures are given as normal climb 80-90kts IAS, en route climb 110- 120kts IAS at 33/2500, maximum perfor­ mance climb being shown as 100kts IAS with 37/2600).

The 32/2500 setting was left on dur­ ing a long, raking climb to Flight Level 200. Pressurisation was dialled in during the climb and atmospheric changes in­ side the cabin were smooth enough to be unnoticed in both front and rear seats.

The pressurisation is controlled via a simple dial low on the panel’s left.

In flight, the Pressurised 210’s general feel is solid and competently reassur­ ing, giving the impression that one is piloting a far bigger aircraft. Basic manoeuvres produced perfectly har­ monised control responses.

Readings at 10,000ft included a 900fpm climb rate with settings of 33/2500, fuel flow 14 US gph. The outside air temperature was logged at +7C, above the ideal temperature.

No diminution of climb rate was noticed en route to Flight Level 200. At that height, settings were maintained at 33/2500 and the test aircraft trimmed into a fast 145 knots IAS.

Outside air temperature was -20C, and temperature compensation resulted in a TAS of 199 knots.

Descent above the standard rate produced more surprises; leaving set­ tings at 33/2500 and setting up a 2000fpm descent, indicated air speed slipped into the yellow arc at 183kts IAS – with an average -10C correction, this worked out to a TAS of 252 knots (291mph).

The air smooth, rate 1 turns were negotiated without undue strain on the air­ frame, wings or control surfaces.

At thicker atmosphere and lower speeds, stalls produced a nodding sink rate without a definite break at 48kts IAS, in dirty condition. Ailerons were operative through the stall.

Circuit work in the P 210 is usual Cessna flexibility. The test aircraft was brought downwind with 10 degrees of flap out and undercarriage down, the base leg brought out 10 more degrees of flap without significant pitch changes, and finals were made with speed coming down from 65kts IAS on short finals.

Power was reduced during a gentle flare, resulting in a satisfying touch.

Rex Aviation says the P 210 can be fitted with a Bendix RDR-160 weather­ scanning radar, to complete the above­ weather capability. A VDU is fitted on the panel, in this mode, the scanner is mounted in a 24Ib wingtip pod.

It goes without saying that the Pressurised Centurion is not every man’s financial cup of tea, the main hurdle being utilisation in the private role.

The aircraft is priced higher than some twins on the Australian market but returns value and capability far above that offered by these twins.

(An advertisement in the Australian media, inserted by Rex Aviation after this test was flown, offered a new P 210 at a much lower price than originally quoted. This could mean the aircraft is too highly-priced in its present bracket).

Data Box

Cessna Pressurised Centurion; six­ place high-altitude single-engine pressurised corporate, charter or private aircraft, retractable under­ carriage high wing type.

Aircraft evaluated supplied by Rex Aviation, Bankstown, NSW, phone 70 0661. Price of aircraft tested $110,000 at time of evaluation, with options fitted and on Australian register.

Specifications: Ramp weight 4016Ib. Max take-off weight 4000Ib. Standard empty, 2345Ib. Max useful load, 1671lb.

Engine:

Teledyne Continental TS10- 520-P turbocharged fuel injected six­ cylinder, 310bhp, 36. 5in at 2700rpm. TBO 1500 hours. Three-blade McCauley 80in propeller, constant speed.

28 volt electrical system, 60 amp alter­nator.

Cabin height 48. 7in. Width 44. 3in. Length 152in. Aft cabin volume 18. 3 cubic ft, max weight 200Ib. Wing area 175 sq ft. Wing loading 22. 9lb/sq ft. Power loading 12. 9Ib/hp.

Usable fuel (standard) 89 galls US.

Performance: Max speed at 17,000ft (ISA) 206 knots. Max cruise 200kts. Sam­ ple settings include 80 per cent power at 5000ft, 171 knots TAS, 9. 2nm per US gallons; at 10,000ft, 180kts with 9. 7nmpg; at 20,000ft, 196 knots at 10. 4nmpg.

At 75 per cent power, 5000ft, 162 knots at 10. 4nmpg; at 10,000ft, 176 knots at 11. 3nmpg; at 20,000ft, 183 knots at 11. 8nmpg.

Service ceiling 23,000ft. Pressure differential 3. 35psi (12,100ft cabin at 23,000ft). Sea level r. o. c. 930fpm. Stall speed, gear and flaps down 58 knots.

Take-off run at sea level ISA con­ditions, 1300ft. Over 50ft obstacle 2160ft. Landing roll 765ft. Over 50ft obstacle 1500ft.

Range at mid-cruise weight 925nm with standard fuel.