key.aero flys the ubiquitous Piper Arrow, familiar to many private pilots.
I’ve always had a bit of a soft spot for the Piper PA-28R Cherokee Arrow III, as it was the first ‘complex’ type I was checked out on. Consequently, when the opportunity arose to take a ‘flight down memory lane’ at Sibson near Peterborough, how could I resist?
Although I have flown many different variants of the Cherokee tribe over the years, it had been a while since I last flew in one so the pre-flight inspection seemed a logical way to start re-acquainting myself with the type. As I always do, I turned on the master switch, made a note of the fuel gauges and then visually inspected the tanks. As I’d expected, the disparity between the gauges and the actual quantities was significant - the two leading edge tanks have a combined capacity of 291 litres, of which 272.5 litres are useable. Although the fuel gauges claimed we were half-full on each side, a look in the tanks suggested that the truth was nearer three-quarters empty! Bearing in mind that of the 72 litres left, more than 18 of them (i.e. a quarter of the remaining fuel) was officially deemed ‘unusable’, it was clear that my first stop would be the fuel pump! With the tanks filled to a genuine ‘half full’, I carried on with the pre-flight.
There is a good spread between the 130kts (IAS) max cruise speed and the 183kts Vne.The Arrow is powered by one of the great general aviation engines – the Lycoming IO-360. It has its 200 horses turned into thrust by a two-bladed constant-speed Hartzell propeller. Access to the engine is excellent, as the entire top half of the cowling can be removed very quickly. There is a small inspection hatch in the top through which the oil quantity can be checked. The undercarriage is retracted and extended hydraulically, with the nosewheel retracting backwards and the mainwheels inward, meaning the Arrow is blessed with a relatively wide-track undercarriage. All three wheels are suspended from oleo-pneumatic shock absorbers and the main wheels are fitted with Cleveland toe-operated hydraulic disc brakes. Generally speaking, the pre-flight inspection of an Arrow is pretty much the same as for any other aircraft in this class, although there is one interesting anomaly – a small probe mounted on the port side of the fuselage. This is the sensor for the ingenious automatic undercarriage extension system - basically, if the airspeed drops below 91kts with a low power setting, the undercarriage automatically lowers (as the probe is located in the propeller slipstream it can ‘sense’ the power setting).
Although early Arrows used a NACA 65 aerofoil on a constant-chord wing (known as a ‘Hershey Bar’ after the popular US chocolate snack) in the mid-1970s the wing was substantially redesigned. From the Arrow III onwards, the span was increased to 10.67 metres and it featured tapered outer panels. The tapered wing reduced drag, producing faster cruise speeds on the same horsepower. Although this proved to be a sound engineering decision, a less productive one was to replace the Frise ailerons fitted to early PA-28s with rather crude, piano-wire hinged flat plate ailerons. The flaps are of the slotted type, as fitted to most of the metal-clad Pipers, and have four positions; ‘Up’, 10°, 25° and 40°.
Another slightly unusual design feature is that pitch control is provided by an all-flying tail, or ‘stabilator’, instead of a fixed tailplane and elevator. Though common to the PA-28 series, it is somewhat curious for an aircraft in this class, and I’ve never really understood why Piper thought it a good idea. It is fitted with a surprisingly large anti-balance/ trim tab and is constructed (along with the ailerons, fin and flaps) from corrugated light alloy.
In common with many other Pipers, there is only the one door. Access to the generously-sized baggage area is via a good-sized hatch on the starboard side. Note that the wingroot walkway is sensibly sized.Access to the generously-sized baggage area is via a good-sized hatch on the starboard side. The baggage bay can carry up to 90kg and is accessible in flight. However, as with most other four-seaters, if you have 90kg of baggage and an adult male on each seat you will definitely not be able to fill the fuel tanks to their maximum capacity – more on this later. The rear seats can also be removed, which increases the baggage capacity. In common with many other Pipers, there is only the one door. Consequently, access to the cockpit is only possible from the starboard side. Although I understand the structural reasons behind this, from a marketing viewpoint I’ve often wondered if having only one door has lost any sales. On the plus side, the wing root walkway is sensibly sized, and there is a small step immediately behind the flap trailing edge. I also approved of the location of the external power socket, which is behind the wing.
The cabin is quite airy, as there are three windows down each side of the fuselage. As the main spar runs under the rear seats the floor is flat, which is obviously better for carrying cargo (after you have first removed the rear seats, of course). Having adjusted the seat, which offers a fair amount of movement both vertically and longitudinally, I strapped myself in and began to re-familiarise myself with the cockpit. The straps are the typical American arrangement of lap strap and separate shoulder strap - I don’t like them, as I suspect they would only be of limited use in an accident. The instrument panel and control layout is typical PA28, and consequently has some features that are perfectly satisfactory, and others that clearly aren’t. For example, I like having a proper engine control quadrant and the flight instruments are arranged in the classic ‘sacred six’ layout, directly in front of the pilot. The undercarriage selector is logically placed and the parking brake, flap lever and fuel valve are all easy to see and reach. On the ‘down’ side, the rudder trim is a bit of a stretch and the circuit breakers are slightly hidden by the P2’s control yoke. Probably the worst feature, though, is the engine instrumentation - apart from the tachometer and combined manifold pressure/fuel flow gauge, this consists of a row of several small oblong dials, as used in many other Piper aircraft. In my opinion, they really aren’t satisfactory, being not only small and poorly-located but also not particularly accurate. The annunciator lights are better placed; there is a big red ‘Gear Unsafe’ light directly in front of the pilot, three small lights for ‘Alt’, ’Vac’ and ‘Oil’, the traditional ‘three greens’ for the undercarriage, plus an amber ‘Auto Extension Off’ and a red ‘starter warning’.
The instrument panel and control layout is typical PA-28.The majority of the avionics are stacked centrally, with the ADF and transponder in front of the P2. The throttle, prop and mixture levers are directly beneath a small row of rocker switches which control the electrics. The rudder trimmer is below the engine controls, with the parking brake just to the left. A friction lock is on the right side of the quadrant, with the ‘alternate air’ lever just to the right. A centre console between the seats carries the elevator trim wheel, emergency undercarriage extension selector and the large, mechanical flap lever (commonly referred to in the States as a ‘Johnson Bar’). On the cockpit wall near the pilot’s left ankle is the large rotary fuel selector, which features three positions: Left, Right and Off. A good safety feature is that a small button has to be pressed before ‘Off’ can be selected.
The engine started easily and I was soon taxiing out. Nosewheel steering is via springs linked to the rudder pedals, and these, combined with the toe brakes, make the Arrow a very simple aircraft to taxi. Visibility over, and either side of, the nose is fine, and the ride quality good – the latter courtesy of the oleo-pneumatic shock absorbers.
Having changed tanks to ensure that both were feeding correctly, I then completed the engine run-up and pre take-off checks. A neat design feature is that the various recommended cruise power settings are printed on the back of the P1’s sun visor. However, I think that Piper missed a trick here, as they would’ve been better on the P2’s visor, while the P1’s could have carried the take-off and landing checklists. Instead, these are below the rectangular engine gauges, and are not all that easy to read. As for flap and trim settings, Piper recommends using 25° of flap for short-field operations, which seems like a lot to me. Pitch trim should be ‘Neutral’, and can be adjusted either electrically by the switch on the yoke (currently ‘inop’) or manually by the wheel between the seats. Rudder trim needs just a little bit of ‘right’ dialled in. It works by altering the tension of bungees attached to the rudder pedals.
The Arrow is powered by one of the great GA engines – it has its 200 horses turned into thrust by a twobladed constant-speed Hartzell prop.All checks complete, I rolled out onto the runway and smoothly opened the throttle. Ambient conditions were an Outside Air Temperature of 22°C and a light south-easterly wind, while with two Persons On Board, no baggage and half fuel I would estimate that we were probably around 235kg below the Maximum All-Up Weight. Consequently the acceleration was quite respectable, and there was absolutely no problem keeping straight. I held just a little bit of back-pressure to keep the weight off the nosewheel, and as the needle of the Air Speed Indicator (ASI) swept past 65kts, I gently eased the control yoke back and let the Arrow fly itself off, an operation which required just over half of Sibson’s 551m runway 15. Once the undercarriage and flaps were retracted and the aircraft trimmed for 90kts, the Vertical Speed Indicator showed around a healthy 1,200ft/min. The handbook recommends a cruise-climb speed of 104kts, with the power set to ’25 squared’ (25ins MP and 2,500rpm) so I adjusted throttle and prop before re-setting the trims. Once level at 3,000ft, a further power reduction to the recommended economy cruise setting of 22ins MP and 2,400 rpm (55%) saw the ASI settle on 120kts Indicated Air Speed (IAS). This gave us a True Air Speed of 127kts for a fuel flow of around 34lit/hr – which isn’t bad for a 1970s four-seater, although it’s also nothing special these days. Speaking of it being a four-seater, in the interests of accuracy it should be pointed out that although its optimum range with maximum fuel is nearly 1,000nm, the bald truth is that it just isn’t possible to fill the tanks and the seats, even with no baggage. To be fair, the same can be said of most aircraft in this class.
An examination of the general handling characteristics, along with a qualitative assessment of the stability and control, revealed no unpleasant surprises. As I recalled from flying other PA28 variants, the ailerons are quite bland, although the lateral control is better than a Cessna 172’s. The Arrow has positive stability both laterally and longitudinally, although from a control viewpoint it is quite heavy in pitch. Directional stability is also positive and the rudder quite authoritative, although a bit on the heavy side. As mentioned earlier, operating the rudder trim requires a bit of a stretch, and this soon began to irritate me. Harmony of control was acceptable, although the breakout forces are on the high side. Engine response is good, and I definitely prefer having a proper throttle quadrant. It’s true that a plunger-type throttle does free up panel space, but personally, I’ll always prefer a quadrant. When compared to its contemporaries the visibility is adequate, although it is certainly not up to the standard of some modern aircraft.
Once level at 3,000ft, a further power reduction to the recommended economy cruise setting of 22ins MP and 2,400rpm (55%) saw the ASI settle on 120kts IAS. This gave us a TAS of 127kts for a fuel flow of around 34lit/hr.Slowing down for an examination of its slow flight and stall characteristics revealed the Arrow to be essentially vice-less. Another trait it shares with most of its contemporaries is that it has clearly been conceived and designed with the average pilot in mind, and the stall is a perfect example of this. Whether power on or off, flaps up or down, and with the undercarriage either retracted or extended, the stall is always pretty innocuous. The stall warning starts bleating well before the critical alpha is reached; there is plenty of buffet and the aircraft consistently broke straight ahead with no tendency to drop a wing. Indeed, with full flap and a bit of power, it was stalling at around 50kts, which I thought pretty respectable for an aircraft in this class. Another example of the Arrow having been designed for ‘Joe Average’ is that there is a good spread between the 130kts IAS max cruise speed and the 183kts ‘Velocity never exceed’.
A good formation flight will often reveal an aircraft’s handling inadequacies, and so it was with the Arrow. Our camera-ship pilot flew as accurately as ever, yet despite the air being beautifully smooth, it was quite hard work putting the aircraft exactly where our photographer wanted it. This should not be construed as a criticism of the type – after all, Mr Piper did not design it for formation work, he designed it as a tourer. And like any aircraft, the Arrow can only be fairly appraised when it is being operated in the role for which it was designed. Okay, the handling is far from perfect, but the same can be said of nearly all its contemporaries.
The POH recommends a cruise-climb speed of 104kts, with the power set to 25ins MP and 2,500rpm.Back in the circuit at Sibson, I reduced speed to 100kts, lowered the undercarriage and then dropped the first stage of flap. The undercarriage can extended at up to 130kts (making it useful as an emergency airbrake), although it must be retracted below 109kts. The flap limiting speed is 108kts. Both flap and undercarriage selection produced small changes in pitch, which were easily trimmed out. Once trimmed, the aircraft is nicely speed-stable. I lowered the rest of the flap as required, although in order to keep the noise down I delayed pushing the prop lever fully forward until short final. Seventy knots felt about right, and each landing was broadly the same – reasonably smooth and in the touchdown zone. My co-pilot certainly seemed happy enough, and as he’s expects a high standard of flying, I was equally happy. To be fair though, the landings probably said as much about the Arrow as they did about my own personal abilities – it really is an honest aeroplane and quite easy to fly.
The Arrow was designed for touring, and can only be fairly judged in this role. It has the ability to carry a fairly useful load over an equally reasonable range, although (and as mentioned earlier) it cannot do both simultaneously. However, it can easily fly two couples, plus some baggage, about 500nm, with at least 45 minutes reserve. I would say that was more than acceptable.
Extracted from an article first published in Today's Pilot magazine October 2006
Filed Under General Aviation Features.
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