Cessna’s Ferrari

In Australia, the 310 has found a place as a very practical aircraft. An estimated 75 per cent of sales over the years have been made to charter operators, according to Australian distributors Rex Aviation.

And keen interest has already been shown in the Cessna 310 R II, the 310 with most options fitted into the asking price.

Used as a six-place long-range executive/personnel transport, the machine makes a strong point in fuel-efficient operation and an economy which can work out to a satisfyingly low $64. 37 total cost per hour (800 hrs/yr utilisation, March 1979 figures).

With a maximum useful load topping 2188Ibs (baggage allowance is 950lbs stowed in nose and two wing lockers, with cabin stowage taking in-flight needs) the 310 has a lot going for it.

With a wide range of fuel options available, the aircraft can span up to 1511nm.

Wichita has gone in hard for in-cabin comfort with the 310 R II, listing options including air-conditioning, stereo e1ghHrack tape player and individual headsets, thermos carrier, oxygen systems, a total “flood” cabin fire extinguishing system, and folding tables.

Despite all this cosmetic embroidery for the passengers, the 310 R II remains a pilot’s aircraft . . .

Just how much was proved during AADR’s evaluation of the 310 R II – VH-RUR, provided for test by Rex Aviation.

Frank Bonnor of Rex Aviation rode right-hand seat to ensure nothing normally unbendable was bent during the checkout.

The copy supplied turned out at $165,000 at the time of flight. Among its recent accomplishments had been a 1050nm mission between Alice Springs and Bankstown, non-stop against a 25-knot headwind. The test aircraft sported a dorsal fin – all types from the P variant onwards have been so fitted. Other innovations include the well-designed waist-high baggage door in the fuselage now being made standard fitting, and the burying of the No. 2 VHF aerial in the vertical stabiliser top.

Fuel management is complex but common, an assortment of fuel tanks in wings, wing lockers and wingtips transferring in most cases by electric pumps.

In repose, the Cessna 310 R 11 sits like the thoroughbred it undoubtedly is. Its lines and stance even at rest can set racing the pulse of even a partisan opposition supporter.

Fail-safe construction makes the 310 series a tough bird, blessed with good looks; with a semi-monocoque fuselage, conventional aluminium wing, horizontal and vertical stabilisers, the wing itself boasts two main spars attaching to the main carry-through spars.

Aileron linkage is a marriage of push-pull rods, bellcranks and cable.

The finish in the test aircraft was first class, externally and within the cabin.

In the lefthand seat, the panel is topped by a high brow itself topping a low coaming, making visibility a joy. The usual Cessna all-round vis. is apparent in this model, and cabin appointments have already been part-listed in this article.

The panel – euphemistically dubbed the Mission Control Center in Wichita’s publicity blurbs – is, as one would expect, both extensive and comprehensive.

In brief, the three main sections are (I to r): Flight instruments; nav/com, transponder, ADF and optional weather radar, engine management systems gauges, – many of them digital readouts.

Under the main arrays sit a host of standard/optional instruments including a 400B autopilot which does everything bar the washing-up.

A short list of standard-fitting avionics lists 300 Nav/Com with VOR/ILS; 300 Nav/Com with VOR/Loc; 300 ADF; 400 Transponder; 400B Autopilot; 400 Marker Beacon; 400 Glideslope; basic avionics kit; audio system; avionics cooling, and antennae. A bank of switches and circuit breakers line the lefthand side of the forward cockpit section – about the only place to put them if you discount the overhead.

Pilot comfort is generously catered for in the seating department, with the optional pilot and co-pilot seats with full articulation plus adjustable pneumatic lumbar support for long hauls or back-prone pilots.

Passenger comfort is both adequate and comfortable; a check during the sortie with a back-seat driver proved this claim, checking comfort, legroom, noise levels and visibility/ ventilation.

Working out weights for distance before startup, it became obvius that the question of fuel versus payload would occur in some flights. Sensible mixes of both items should satisfy all but the most inflexible operator/owner.

Full fuel is listed at 20:3 gaols US usable, stowed in wingtip mains (100), in-wing auxiliaries (63) and wing lockers (40).

With about 100 gallons US on board for the test flight, the total weight for this evaluation was about 1040 under the carded gross take-off weight of 5500lbs.

Start drill for each of the Teledyne Continental I0-520-M engines is standard fuel-injection patter, getting each of the six-cylinder motors into action. Each engine is rated at 285hp at 2700rpm, driving a tri-blade McCauley constant-speed 6ft 4. 5in props.

Basically, engine start entails prop clear, mag on, press starter button, prime switch ON, aux. fuel pump on LOW to purge vapour from the system, and throttle set to 800- 1000rpm after firing.

Engines grumbling away surprisingly quietly – as befits such a prestige best-avionics master switch was energised before roll.

Ground ride is smooth, with no suggestion of waddle or shimmy and brakes checking out true and progressive.

Visibility is typical Cessna.

Control accessibility in the 310 is pilot-orientated, no obvious snags in control or instrument placement being observed.

Ground manoeuvring presents no problem, thanks to a 48ft 8. 5in turning radius. is relatively simple for such a sophisticated-looking twin apart from cockpit checks, the mechanical drill basically entails runup to 1700rpm, checking vacuum at between 4. 75 and 5. 25 in Hg, and mags. Prop feathering drill looks for cycling back to 1200rpm.

Outside air temperature registered +12C as clearance from Bankstown was obtained, and 15 degrees of the flap on the three-position pre-select detent was selected (Flap positions are 0, 15 and 35).

Initial runup is made against brakes in the take-off phase.

Brakes off, the 310 R II leapt forward, needing a trim and a surprisingly small amount of right rudder to track the centreline.

Rotation was initiated at 75kts IAS, with wheels off at 80 _ kts IAS. Take-off run (ISA conditions) is given as 1335ft, but this was bettered handsomely with the weight on board. Full throttle and 2700rpm got the test aircraft through Vmca of 80kts in a blink.

Initial climb speed after positive climb was established and wheels up selected (the gear was raised and tucked away m a 10-second cycle) registered at 85kts, and settled on 100 IAS with 1500 showing on the VSI in a leisurely climb, flaps up.

Settings were then adjusted to the 25125 pattern.

The Cessna 310 R ll’s low noise level became even more apparent as cruise settings of 24/24 were adjusted, giving about 67 per cent power on the way up to 4000ft. True airspeed was a satisfying 165kts.

A short session of general handling gave the lie to critics’ assertions that the clean wing showed shortcomings at low speed; although listed stall speed, flaps up and power off, is given at 78kts IAS, it was possible to make respectable turns at 75kts IAS in this sortie without being assailed by either judder, buffet or a cacophony of warning hooters, bells or other red lights.

Control response in the aircraft is crisp with precise amounts of input/output being possible. Cessna claim that controllability in the 310 R II is among the best in its class especially in single-engine performance. ‘ Stalls in clean and dirty conditions produce a reluctance to break and a fair sink rate. At this time Wichita’s undercarriage warning system came into its owl . . .

The undercard warning horn blasts off with intermittent sound if either throttle is retarded below 12 in Hg with gear up or 1f flaps are lowered more than 15 degrees with gear up – or in any position but down and locked.

(Emergency gear lowering is by hand crank, incidentally. ) A short session with the 400B autopilot preceded single-engine performance evaluation.

Suffice it to say _that the 400B is very much an all-singing, all-dancing, giving altitude lock, heading acquisition and another facility. A bell and visual warnings denote malfunction.

Entering a single-engine flight phase (in non-emergency conditions) means etching the Vmca of 80kts IAS in one’s mind, and recalling clean and dirty stall speeds of a standard condition on 78 and 70kts IAS respectively. The basic drill is, according to the manual and this flight, identify; throttle closed; mixture to idle Cut-Off; prop feathered; aux fuel pump OFF; mag. OFF; prop synchrophaser OFF (if fitted)· alternator OFF, internal cowl flap closed. With about 75 per cent set up on the “live” engine, IAS around the 100kts mark, it was possible to make turns into and away from the “dead” engine, with even a steep turn only just kicking the ball out of its normal home.

Climb? Cessna claims 319fpm at 7500ft. The test aircraft was 3500ft under that and registered a relatively approximate figure without strain or pain.

In continued flight, trimming about five degrees of the bank into the operative motor makes asymmetric flight a non workload. Wichita recommends paring the electrical load down to minimum needed during this phase.

Back to cruise configuration; the 310 R ll’s cruise performance flexibility can be gauged by the following: At 7500ft with a cold -20C showing and using the EGT for optimum economy, 64. 4 per cent (2300122) should show you 176kts IAS with fuel consumption of 163Ibs. hr.

At 10,000ft, 2400/18 (54. 4 per cent) should give you 167kts IAS with a consumption of 141Ibs/hr. A landing and take-off at Camden confirmed the ease with which the 310R II can be flown in other configurations.

Circuit entry and circuit work speeds were attained with minimum fuss, coming back to 2100/20. 5 for starters.

Fifteen degrees of flap were hung out, with noticeable pitch change. Trimming for undercarriage lowering, final approach was made with 2000/14 on and above minimum approach speed of 93kts IAS.

Heavy elevator forces were apparent on finals, making more trimming essential for any sort of accurate placement.

Trim was eventually pulled back almost to maximum travel.

Speed eroded through Vmca of 80kts IAS to about 75 before the touch. Flare is gentle – in this case float was longer than usual (pilot trouble, no fault of the aircraft).

With braking, the test aircraft was halted in significantly less than the booked 640ft condition figure.

Backtracking for take-off, figures to remember were recounted: Accelerate-stop distance, standard day, nil wind at 5500I6s, 92kts to zero, 3645ft. 1 Standard-condition manual recommendations for takeoff include raising nose-wheel at 83kts IAS, liftoff at 92kts IAS.

Back in the Bankstown circuit, a short-field landing was demonstrated by Frank Bonnor. His figures included a 110kts IAS turn to finals, settings of 14/2000, speed back to 80 on short finals, full flap hung out early and 75 on the clock just before touch.

His distance mark? about 400ft, with braking.

Briefly summing up; the Cessna 310 R II is indeed a tractable _aircraft with long legs – depending on the payload/fuel mix, ideal for charter, corporate transport or even private work.

Flown within its normal limitations it shows none of the vices so often recounted by some pilots who often delight in listing their “almost dead” episodes at the expense of a perfectly good machine’s name.

Finally, some figures with which to round off details already given in this test report.

Va, 148kts IAS. Vfe (15 degrees) 158kts IAS, 30 degrees 139kts. Vie 138kts. Vlo 138kts. Vmca 80kts. Single-engine rate of climb speed (Vy) 107kts. Vne 227kts. Vno 183kts.

Significant speeds are marked in coloured arcs on the ASI.

Cessna’s manual recommends switching auxiliary fuel pumps on at heights above 12,000ft to minimise vapour formation, and lists general cruise settings at between 2100 and 2500rpm, with 15 to 24. 5 in Hg.