Piper PA-28RT Arrow IV Turbo

minutes to climb from sea level to its service ceiling of 16,000 feet. The Turbo Arrow IV that I flew for this report is a 1980 model owned by three business partners who lease it back to a fixed-base operator for rental. The airplane, N8242L, is really loaded with options, including a three-blade pro- peller, an Autocontrol IllB autopilot, electric pitch trim and a full King panel with a KNS-80 area navigation system, a KY-197 transceiver, a KX-170 nav/ com, a KR-86 automatic direction find- 32 • JANUARY 1961 er as well as a KMA-20 audio panel. Pilots familiar with the normally as- pirated Arrow will have little difficulty transitioning to the Turbo Arrow. Of prime importance is careful attention to power management. Valuable informa- tion on proper engine operation is available in a Continental manual for the TSIO-360-FB engine. The basic panel in the Turbo Arrow is similar to that of the Arrow, except for the presence of an overboost warn- ing light on the annunciator panel, a three-position auxiliary-fuel-pump rocker switch and a manifold-pressure- line drain valve. The overboost light will illuminate when manifold pressure exceeds 41 inches (redIine on the gauge). The top of the auxiliary-fuel- pump switch is labeled LO and can be depressed to suppress vapor pressure in the fuel lines, if the engine begins run- ning rough while idling or while oper- ating at high density altitudes. The HI setting on the bottom of the switch is guarded by a manually operated latch and should be used only if the engine- driven fuel pump fails. The manifold- pressure-line drain valve is located be- hind the bottom left-hand side of the panel, out of sight. It is depressed for about five seconds during runup at about 1,000 rpm to expell any moisture or any fuel that may have accumulated in the manifold pressure line as a result Soft velour seats and hard King avionics are some of the features offered as options. lURBOfRROW of overpriming the engine during the start. The drain valve is needed in the Turbo Arrow because any accumulated moisture or fuel could be forced up into the manifold pressure gauge when pressure within the line increases- above about 30 inches. At lower pres- sures, moisture and fuel are pulled back up into the engine. N8242L is equipped with the op- tional engine primer system, which is designed specifically to aid engine starts in cold weather. Set the mixture control to Full Rich and push the throt- tle and prop controls full forward. De- press the spring-loaded primer button on the panel for about two seconds, close the throttle and engage the start- er. I followed this procedure during engine starts in a variety of ambient temperatures; each time, the engine rumbled to life on cue. The main shaft of the turbocharger is lubricated by engine oil. Therefore, the engine should be operated at between 1,000 and 1,200 rpm until the engine oil warms up to at least 75° for the run- up. Continental advises that the oil temperature should be at least 100" be- fore beginning the takeoff roll. On takeoff, the throttle should· be advanced slowly and smoothly to allow the manifold pressure to stabilize while the turbocharger spins up. After about 30 inches is reached, the turbocharger spins up quickly to its 41-inch redline. I found that a takeoff setting of 38 inches provides ample power for take- off and a comfortable margin from the redline. Continental advises that the engine can tolerate a manifold pressure overshoot to 43 inches for less than 10 seconds. The company also warns that manifold pressure overshoots above these limits will damage the engine. The Turbo Arrow shows no inclina- tion to fly itself off the runway, but an assertive tug on the yoke will get the airplane airborne between 70 and 77 knots, depending on load. The airplane accelerates quickly to its best-rate-of- climb speed of 97 knots. After obsta- cles have been cleared, the power con- trols should be pulled back to 33 inches and 2,450 rpm for a cruise climb speed of 104 knots. The ground roll for a normal takeoff is about 1,110 feet. Short-field takeoffs require finesse. The backup gear-extension system must be overridden manually since, in addition to its primary function of au- tomatically extending the gear below an airspeed of about 103 knots, the system also will prevent the gear from being raised below about 78 knots. The system is overridden by pulling a switch located forward of the elevator trim-control wheel between the front seats. With 25 degrees of flap, the air- craft is accelerated to a rotation speed of between 53 and 64 knots. When the gear is retracted, the aircraft is acceler- ated to its best-angle-of-climb speed, 79 knots, until obstacles are cleared. Piper says the Turbo Arrow requires a horizontal distance of 1,620 feet to clear a 50-foot obstacle on takeoff. The oil temperature gauge and the cylinder-head temperature gauge (stan- dard equipment on the Turbo Arrow) should be monitored closely while climbing to prevent overheating. The Turbo Arrow has no cowl flaps, and proper engine temperatures can be maintained only by adjusting mixture and airspeed during the climb. Piper says a full-rich mixture should be used during both takeoff and cruise climb. During an evaluation flight with just myself (150 pounds) and a full 72-gal- Ion usable fuel load aboard on a stan- dard day, the Turbo Arrow averaged 1,200 fpm during takeoff climb, 800 fpm at a 104-knot cruise climb through 12,000 feet and about 500 fpm through 17,500 feet. With the mixture leaned to 100 de- grees rich of peak exhaust gas tempera- ture, the airplane provided a true air- speed of 178 knots at 75 percent power at a density altitude of 16,500 feet, 160 knots at 65 percent power and 150 knots at 55 percent power. At 10,500 feet, the true airspeeds were 160, 148 and 135 knots, respectively. I used a portable Scott oxygen sys- tem during evaluation flights at high altitudes and found it is easy to use but limited in capacity; plus, it takes up a lot of room in the rear seats. This year, Piper is offering the built-in system - used in the Turbo Seminole twin as an option. The 48.3-cubic-foot-capacity bottle is located in the tailcone and provides 8.5 hours of oxygen for one AOPA PILOT' 33 person at 20,000 feet, 4.2 hours for two people, 2.8 hours for three and 2.1 hours for four people. The optional, built-in oxygen system costs $2,265 and for weight and balance must be accompanied by the optional three-blade propeller ($1,005). It is in- teresting to note that the external noise level of the aircraft with the three-blade prop is 72.8 decibels, almost 3.4 dB higher than the noise level for the two- blade prop. However, while the noise amplitude is higher with the three- blade prop, it is of a different frequen- cy and provides more comfortable per- ceived sound levels in the cabin. A close watch on the oil and the cyl- inder-head temperature gauges also must be kept during descent to avoid supercooling the engine. I found that setting the engine controls for 20 inches and 2,400 rpm, with gear down, provides descent rates of between 1,400 and 2,000 fpm at an indicated airspeed of about 135 knots, well be- low the maximum structural cruise speed (Vno) of 152 knots. The oil and the cylinder head temperatures stayed well within their green arcs at these power settings. For less hasty descents, 24 inches and 2,400 rpm with gear up and airspeed just below the yellow arc will deliver about 1,000 fpm. The Turbo Arrow is a pleasure to fly in stable air. The controls are light and well-balanced. Once trimmed in a steep turn, the Turbo Arrow maintains attitude nearly hands-off. However, in turbulence, the airplane tends to wal- low quite a bit. This seems to be char- acteristic of all members of the short- coupled Cherokee series of aircraft. The Turbo Arrow III that I flew also 34 • JANUARY 1981 The turbocharged engine requires stricf aHenfion fo mixture control and airspeed in climb. 1URBOAmOW wallowed in rough air. In the Turbo Arrow III and IV, this is quite uncom- fortable, especially at lower altitudes where even low power settings tend to send the airspeed indicators close to or into their yellow arcs. This year, the Turbo Arrow IV, as well as all other aircraft in Piper's 28 and 32 series, will come with a yoke- mounted transponder ident button as standard equipment. New options, in addition to the built-in oxygen system, include a CG plotter, a digital clock, Century 21 and 41 autopilots and a wider assortment of King, Bendix and Collins avionics systems. The aircraft's list price has been raised from last year's $55,730 to $64,520 this year. Airworthiness directives have been issued by the Federal Aviation Admin- istration regarding the fuel and the oil lines in the Turbo Arrow and on its fuel-tank vent system. After a rash of service difficulty reports of broken nose-gear downlock assemblies, Piper incorporated a strengthened hook into the assembly in 1977. There also were a number of reports of crankshaft fail- ures in the engines of Turbo Arrows and Senecas. In 1977, Continental beefed up the crankshaft, and Piper and Continental both agree that this has licked the problem. Continental said that a good service history for the TSIO-360-FB engine was what prompted it last year to raise the TBO from 1,400 to 1,800 hours. The Turbo Arrow offers a good bal- ance of performance, mission flexibility and economy of operation. During a recent round-trip flight between Fred- erick, Maryland, and Indianapolis- when strong winds and low ceilings prompted me to keep the airplane be- low 9,000 feet-the Turbo Arrow IV provided true airspeeds between 150 and 165 knots at 75-percent power and burned an average of about 13.5 gph. Overall, the Turbo Arrow is a very- appealing aircraft. Good performance and low maintenance costs make the airplane an excellent choice for person- al travel and business flying. 0 740 nm 770 nm 20,000 ft 12,000 ft 645 ft 1,555 ft PIPER PA-28RT-20lT TURBO ARROW IV Basic price $55,730 (1980) Price as tested $94,000 Specifications Engine Teledyne Continental TSIO-360-FB 200 hp @ 2,575 rpm (sea level to 12,000 ft) Recommended TBO 1,800 hr Propeller Hartzell, constant speed, 2-blade (std), 3-blade (opt, as tested) 76 in Wingspan 35 ft 5 in Length 27 ft 4 in Height 8 ft 3 in Wing area 170 sq ft Wing loading 17.06 Ib/sq ft Power loading 14.5lb/hp Passengers and crew 4 Cabin length 8 ft 1 in Cabin width 3 ft 3 in Cabin height 4 ft 1 in Empty weight 1,6901b Empty weight (as tested) 1,8811b Useful load (basic aircraft) 1,210 Ib Useful load (as tested) 1,0191b Payload wi full fuel (basic aircraft) 7781b Payload wi full fuel (as tested) 5871b Gross weight 2,9001b Fuel capacity (std) 77 gal (72 usable) Oil capacity 8 qt Baggage capacity 200 Ib (26 cu ft) Performance Takeoff distance (ground roll) 1,110 ft Takeoff over 50 ft 1,620 ft Rate of climb (gross weight) 940 fpm Max level speed (14,000 ft) 178 kt Cruise speed (75% power, 10,000 ft) 154 kt (75% power,20,000 ft) 170 kt Cruise speed (65% power, 10,000 ft) 146 kt (65% power,20,000 ft) 166 kt Cruisespeed(55% power, 10,000 ft) 136 kt (55% power,20,000 ft) 156 kt Range @ 75% cruise (wi 45-min reserve) 10,000 ft 660 nm (wi 45-min reserve) 18,000 ft 695 nm Range @ 65 % cruise (wi 45-min reserve) 10,000 ft 685 nm (wi 45-min reserve) 20,000 ft 720 nm Range @ 55% cruise (wi 45-min reserve) 10,000 ft (wi 45-min reserve) 20,000 ft Max operating altitude Critical altitude Landing distance (ground roll) Landing over 50 ft Limiting and Recommended Airspeeds Indicated airspeed, not calibrated Vsi (Stall clean) Vso (Stall in landing configuration) Vne (Never-exceed) Vno (Max structural cruise) Va (Design maneuvering) 2,9001b 1,893 Ib Vfe (Max nap extended) Vie (Max landing gear extended) Vlo (Max landing gear operating) Vx (Best angle of climb) Vy (Best rate of climb) Based on manu{acfurer 's figures 66kt 61 kt 193 kt 152 kt 124 kt 96 kt 108kt 133 kt 111 kt 79kt 97kt