Flight Impressions – Pilatus PC-9 & CT-4A

The author flew in aircraft A23-039 in Roulettes livery, callsign Alladin 404, the command pilot was Wg Cdr Frank Atkins, formerly an F-111 aerobatic display pilot and currently assigned to the staff of Training Command HQ at Point Cook. Preparation for the flight involved helmet and G-suit fitting, the latter a most interesting procedure which typically takes a quarter of an hour, during which time a life suppor t fitter will undo all of the laces in the suit, and adjust the waist, thighs and calves for a suitable fit.

Preflight checks for aircrew also include a series of checks on the Martin Baker MK AU11A ejection seat, which requires the removal and stowage of a range of pins. Once the crew is seated, the seat heights must be adjusted with the servo switch on the RHS of the seat, the G-suit hose must be connected to its high pressure air feed to the left of the seat, and the oxygen hose and intercom lead must be plugged in.

The cockpit layout is much like that of a modern fighter, but is simpler due to the absence of a HUD and offensive, defensive and weapon control panels and displays. The Power Control Lever (PCL) is situated to the left, with a rocker switch for rudder trim on the lower front of the handle, while the fighter style control stick is conventionally located with pitch/roll trim via a standard ‘coolie hat’ switch at the top. The pedals are large, comfortable and well positioned.

The gear select and indicators are situated at the junction of the left console and control panel, the console also mounts the three position flap selector, trim system controls, anti-ice, emergency fuel controls and a breaker panel. The right console is occupied with electrical system controls, lighting controls, attitude/heading reference system (AHRS), environmental control system, engine starter and oxygen regulator controls, with another breaker panel to the aft of the console.

The engine instruments are to the upper right of the instrument panel, with analog displays for engine torque, turbine inlet temperature, RPM, supplemented by displays for oil temperature/ pressure and fuel contents. In addition, digital readouts of fuel remaining, fuel used and fuel flow are displayed, together with hydraulic accumulator pressure. The centre of the panel is occupied by the two Multi Function Displays of the Bendix EFIS. The upper MFD displays the ADI (Attitude & Direction Indicator), with AoA ladder and roll angle symbology, compass heading and ILS glideslope when selected, while the lower is a HSI (Horizontal Situation Indicator) display which provides a DG rosette, ADF, VOR and Tacan displays in its various modes. A standby conventional ADI (AH) is situated to the left of the panel.

Basic flight instrument displays are conventional, with an altimeter to the right of the MFDs, and a VSI beneath it, and an ASI to the left, beneath which is a conventional ADF display. The G-meter is conveniently to the left of the ASI. The lower part of the panel left to right mounts a conventional clock, emergency gear release handle, comm1, comm2, EFIS controls, a Nav/ Tacan, ADF and transponder display, the parking brake and to the lower right, a master warning telltale panel.

The bubble canopy is side hinged and provides outstanding visibility from both seats, more typical for a fighter than a trainer. The absence of windshield framing provides excellent forward visibility to either side and the elevation of the seats further enhances the effect.

The flight took place from RAAF Laverton early in the afternoon, with 2/8 cloud at about 2,500 and light wind providing close to optimal conditions for a mixed aerobatic and circuits session. After strapping in and shutting the canopy, Frank started the aircraft, carried out the required checks and radio calls and taxied to the holding point for RW 23, prior to taxi the seats were armed by removing the master arm T pin, which each crewmember stows in a receptacle on the canopy frame. I was given a brief on the ejection procedure in the event of an engine failure during takeoff, after which we lined up and I was given the aircraft for takeoff. Power control lever (PCL) to 40psi torque, the aircraft accelerated very rapidly, at which point I was told to advance the PCL through the gate to max power. I was late with my bootful of right rudder, drifted off the centreline but subsequently corrected and rotated the aircraft gently at 80 KIAS. At climb attitude the aircraft accelerated very quickly to 130 KIAS, with gear up I climbed out tracking over Werribee to R314C/D310 over the peninsula to the South. The aircraft climbs very rapidly and requires very little stick force to maintain proper attitude, little pitch trim was required but considerable rudder trim was needed with any change in PCL setting. We levelled off at 6,000ft and very shortly arrived over our objective.

My initial impression was very favourable, as the aircraft has very light and responsive controls yet is extremely stable and consequently feels very predictable. Rolling out of turns, it has no detectable undershoot or overshoot, this perception was further reinforced throughout the flight. We commenced the handling demonstration with a power off stall. PCL toidle and increasing backstick, the aircraft feels very stable until just prior to the onset of the stall, where there is a decrease in the effectiveness of the controls. The stall occurs clean at 75 KIAS and is evident from slight buffet. Stall recovery is conventional, with sufficient forward stick to unstall the wing while the PCL is advanced to full power. Beware those late with rudder, when the PT6 bites, it bites, the acceleration is very rapid and again generous right pedal is required until the rudder is trimmed. The rudder trim on the PCL is well located and comfortable to use, although my personal opinion is that gearing it a bit faster wouldn’t hurt The next step involved basic aerobatic manoeuvres and steep turns. Basic manoeuvres are entered at 200kt level, combination manoeuvres require a slightly higher entry speed of 250kt. The aileron roll is very easy, the aircraft attaining its full roll rate very quickly with very little stickforce required and no alternating rudder input. The nose sits on the horizon and recovery to level flight is achieved cleanly with no perceptible undershoot or overshoot. The low moment of inertia in the roll axis and effective aileron yield a very high instantaneous roll rate, with the high sustained rate and superb control damping providing for a neat and fast roll with very little practice.

The loop is also flown very easily, with very slight stick force required to maintain 4g in the first phase of the manoeuvre. Directional control through the pullup and over the top is excellent with very little aileron required to maintain wings level. Throughout the manoeuvre the aircraft feels stable and smooth. The pitch response throughout is sufficiently sensitive to provide for a very precise manoeuvre with a minimum of stick force.

Similarly, the stall turn benefits from the superb handling of the aircraft, with slight forward stick and generous aileron over the top, the aircraft is well behaved through the central phase of the manoeuvre and requires little opposite rudder to arrest the yaw rate into the nose down attitude. The nose down attitude is held shortly for the engine to stabilise, while it belches blue smoke from its exhausts, and recovery from the dive is easy and smooth.

The PC-9 is a superb aerobatic platform and will perform well with far less effort than is required to cleanly manoeuvre typical GA aerobatic trainers. The responsiveness andexcellent control damping allow precise control of the aircraft with little control force and the superb visibility provides for easy orientation throughout the manoeuvre. There is really no excuse for poor aerobatic flying in the PC-9.

The PC-9 enters a steep turn smoothly and again only slight back stick is required to hold the nose rock steady on the horizon, while maintaining a constant turn rate, again recovery is smooth with no observable overshoot or undershoot.

At this point in the flight I found that the G-suit was getting the better of me, being accustomed to 3. 5-49 without a suit I found that getting crushed at 1. 5g or so and thereafter made me very uncomfortable. Bonedomes, G-suits, overalls and Mae Wests (correctly the Secumar life preserving vest) take some getting used to (a note of warning to those GA pilots seeking a fast jet career!). I discovered much to my surprise that I overheated very quickly and hit the limit of my manoeuvre endurance for the day at afraction of what I am accustomedto. As a result I wimped out and decided, to the disappointment of my command pilot, to forgo thespin, roll off the top and halfCubanI had intended to do. Disconnecting the G-suit made a real difference, so I continued on with some turns before returning to Laverton for circuits.

The PC-9 is a sheer pleasure to fly, be it aerobatics or simply general handling. The controls are light, responsive and perfectly damped, but retain a measure of the firmness which is preferred in military trainers. Even beginners will find that the aircraft inspires confidence very quickly and always feels very predictable and stable.

Enroute back to the Laverton circuit Frank demonstrated the various modes of the EFIS. The MFDs are full colour CRT units which are well readable even in bright sunlight with the dark helmet visor down. The HSI provides a graphical representation of the 360 degree rosette overlaid with the ADF needle, the VOR or Tacan modes provide a very readable central deviation indicator together with the bearing display. In addition, the Tacan mode supports a plan position display rendering of the aircraft relative to the beacon and its pattern of radials. For precision instrument flight (IF), the standard 360 degree displays can be switched to an enlarged sector display, which expands the forward 45 degree sector across the whole HSI, vastly improving the resolution of the rosette. The upper MFD is used as an AH with a supplementary compass scale and also provides glideslope bars if selected. DME/Tacan selection provides a readout of absolute velocity to station, which is an accurate groundspeed when heading to/ from the station. The PC-9’s smooth and precise handling characteristics make for an excellent IF training platform, this is further enhanced by the highly capable EFIS. The RAAF’s student pilots will have an unfair advantage over their civilian counterparts in IF training with this level of capability. Entering the circuit, the PCL was set to about 18psi for 130 KIAS, with the gear lowered at mid downwind. With the gear down the aircraft decelerates rapidly and a slight nose down pitching moment is experienced. Advancing the PCL to 21psi or so and a slight application of elevator trim appears to be adequate and the aircraft is very easy to hold exactly at the 1,000ft altitude. The precise handling characteristics are in no way degradedevenat this low speed, in a dirty configuration. Weflew several circuits, one of which was a go-around due to my inexperience in flying RAAF circuits, ie I rolled out on final past the centreline. The go around is conventional, with application of full power and the gear retracted once a climb configuration is established. The RAAF’s training videotapes emphasise the several seconds of lag in engine response following PCL movement, at low psi settings, but I did not find this to be a serious deficiency in handling as typically underpowered civilian trainers takethat amount of time to get moving, even if the engine responds instantaneously. PCL setting for base is about 10psi and will need to be adjusted for the circuit, the aircraft’s speed is allowed to slowly wash off on base down to 95 KIAS on finals. The PC-9 is comfortable on finals and the visibility is superb, even over the long nose. The aircraft flares nicely at about 85-90 KIAS and will smoothly sink, without a tendency to balloon as one comes to expect with an aircraft with a sensitive elevator. Due the absence of any significant crosswind there was no opportunity to see how the aircraft sideslips wing down on short final, but given its docile handling this would be unlikely to present any unwelcome surprises.

On landing once off the runway, the seats are secured with the masterpin, the canopy is left closed until shutdown. Needless to say the G-suit went off very quickly, once out of the aircraft. My RayBans were evenly coated with a foggy film of sweat. The PC-9 is clearly a superlative training aircraft, with excellent handling characteristics and impressive performance. It is however a handful initially for an inexperienced aviator and will without any doubt sort the men from the boys in thefirst 20 hours of the syllabus. Beyond that point, the PC-9 will bring out the best in any student, and offers much growth before the student hits the aircraft’s inherent limitations. Future tactical pilots will benefit considera. ,ply from early exposure to fighter like handling and performance, and the aircraft will certainly facilitate selection of suitable candidates for follow on fast jet conversion. And I envy them very, very much.

The Parrot – Flying the CT-4A

The CT-4 has faithfully served the RAAF as a basic trainer since the early seventies, turning out a generation of pilots. Affectionately known as the Parrot, the CT-4 has all of the attributes which make a good basic trainer, it is docile, predictable and a

pleasure to fly. Australian Aviation had the opportunity recently to fly this aircraft, soon to be phased out of the RAAF’s inventory, and found the Parrot to be well deserving of its reputation. The CT-4 is a derivative of the Victa Airtourer, and was customised for the military basic training role by structural stengthening, the use of a hinged bubble canopy and the fitting of military style stick/pedal/throttle controls. In comparison with civilian basic trainers such as the Piper PA-28 family, the CT-4 while of similar fixed tricycle configuration, has a smaller wing with a higher loading, a much more powerful engine, vastly superior visibility and is of course is fully aerobatic. This translates into an aircraft which in the author’s author’sopinion, is a far better basic training platform due to not only boasting a better performance envelope, but is also much easier to handle in the circuit and is far more tolerant of mishandling in unusual attitudes. The aircraft flown was A19-61 and the author flew with Flt Lt Chris Abbot, a RAAF QFI with 1 FTS at Point Cook in Victoria. The weather conditions on the day were optimal, CAVOK with light and variable winds, which allowed for some basic aerobatics in addition to handling familiarisation and circuit work. The first impression is of an aircraft which is solidly built, all metal and very structurally robust. Ground preflighting is standard for a small piston, with checks on control surfaces, prop, engineand fuel. Access is over either wing, and the flaps are sufficiently solid to stand upon on marked areas, unlike its civilian counterparts. The cockpit is spacious by any standard, with large and comfortably adjustable pedals, centrally mounted control sticks and dual throttle, pitch and mixture controls on consoles on the left hand position to either of the two side-byside seats. The pleasant surprise upon strapping in is the superb all round visibility conferred by the large bubble canopy and single piece bubble windshield. The canopy is latched via a central handle to the windshield frame and can be left cracked open for taxiing, well worth doing in consideration of the glasshouse heating experienced in sunny conditions. The RAAF fly the Parrot in standard overalls, wearing flotation vests, helmets and optionally backpack parachutes, this somewhat complicates the strapping in procedure as one has additional straps to worry about and an additional shoulder harness lock to engage. By all 11′. !eans an interesting experience for us jeans/T-shirVheadset aviators. The cockpit layout is quite conventional, the notable difference being in the use of electric trim throughout, with a panel mounted rudder trim and control stick mounted aileron/pitch trim. The powerplant is a flat six Continental IO-360-H rated at 210hp, with a button operated starter and rotary switch for magneto selection.

The aircraft taxis comfortably and with the exception of more extensive RAAF checklists, getting through the runups, pre-akeoffs and to the holding point is no different from any other small piston with a constant speed prop.

On takeoff the extra horsepower is quite noticable and for those accustomed to the C172 and PA-28, it will be quite refreshing. The aircraft is rotated at 60kt and requires little rudder to maintain a precise track down the centreline. The first impression of the controls is of smoothness, the CT-4 exhibiting the pleasant firmness which is typical for the military trainer.

We climbed out at 90kt toward the training area to the SouthWest of Point Cook, the aircraft maintaining a steady climb rate of about 600fpm at 26 inches. At 2,500ft we levelled off to carry out some gentle turns followed by somesteep turns. Control response is quite precise, with very little overshoot in all three a xes and rolling out from turns, very little opposite control input is required to arrest the turn. Slight backstick is required in a steep turn to maintain the correct attitude, and the aircraft feels very comfortable throughout the manoeuvre.

I put the aircraft through a series of small pitch, roll and yaw control inputs and the aircraft attains the commanded rate quickly and smoothly, and similarly upon centralising the control, smoothly recovers attitude without the typical underdamped response of most civilian trainers.

At this point, we commenced some basic aerobatic manoeuvres, Chris initially demonstrating the manoeuvre, then setting up for a repeat of the manoeuvre and handing the aircraft over. Standard aerobatic power is 2600/26 inches and entry speeds are 130kt for rolling and 150kt for vertical manoeuvres.

The elevator is suprisingly sensitive in the loop, and little backpressure is needed to maintain the required 3. 5g. The smoothness of the controls is again apparent, and the aircraft will fly a very nice loop with little control force required to maintain the appropriate load factor through the various phases of the manouvre. The CT-4 rolls nicely and recovers cleanly, the low moment of inertia due to the small wing is a distinct benefit in comparison with civilian trainers such as the Decathlon. The stall turn is also flown very easily, with just a little forward stick required to maintain the plane of the turn, with full rudder and opposite aileron. Entering the latter phase of the stall turn, little opposite rudder is required to arrest the yaw rateinto the nose down attitude.

The overall impression is of an aircraft which is very pleasant to aerobat and requiring little effort to manoeuvre well, any reasonably experienced aerobatic pilot will find it both easy and comfortable to handle. The controls are sufficiently sensitive to provide for precise handling through the manouvre, without the poor damping which is characteristic of some civilian aerobatic trainers.

Having completed this phase of theflight, we returned to Point Cook for somecircuits, The CT-4 handlesnicely in the circuit and little effort is required to maintain track and attitude on final. The aircraft sinks gently in the flare, with no observable tendency to balloon or float as is typical with lightly loaded aircraft. Application of power during thetouch and go results in very quick acceleration to flying speed and little backpressure is required in spite of the trim set for finals. The CT-4 is an easy aircraft to land and again little practice will be required to fly precise circuits.

We carried out several circuits before the final full stop, the RAAF oval circuit requiring some getting used to (RAAF circuits differ from the civilian rectangular circuit, in that the crosswind and base legs are collapsed into continuous turns from upwind to downwind, and downwind to final respectively).

The Parrot’ is the nicest basic trainer the author has had the pleasureto fly, and is well worth the consideration of enthusiasts seeking an aerobatic side-by-side seated tourer. With the 1 F TS aircraft due for disposal upon the introduction of the new RAAF training scheme (refer p. 22 Oct 91 AA), the CT-4 will hopefully become available to the private pilot.

The Parrot will no doubt be missed by many RAAF pilots but hopefully its eventual emergence in the civilian training market will allow others to enjoy this pleasant little aeroplane.

Acknowledgements: Special thanks to Wg Cdr Frank Atkins and Sqn Ldr Greg Smith of HQ Training Command for their extensive assistance in the preparation of this series of articles