Flight Test: Piper's Classic Cruiser - The Comanche
PUBLISHED: 11:26 30 March 2017 | UPDATED: 11:26 30 March 2017
The elegant Piper Comanche still impresses today, especially after a splendid refurbishment. Words by Dave Unwin. Photos Keith Wilson
Filthy, forlorn and with flat tyres, the PA-24 at the back of the hangar was certainly a sorry sight. Keith and I regarded it in stunned silence. “That can’t be it!” he said. “Well if it is, I’m not flying it!” I retorted. Retracing our steps, we both practically sighed with relief when we spotted what looked like a brand-new Comanche gleaming in the sunshine outside the Dukeries Aviation hangar at Netherthorpe airfield. “That’s more like it,” we chorused!
The Comanche occupies its own particular place in aviation history, as it was the first all-metal aircraft built by possibly the greatest-ever manufacturer of fabric-covered aircraft; Piper. Although a steady stream of aircraft had flowed from Piper’s Lock Haven, Pennsylvania plant over the preceding twenty years, by 1957 the various versions of Cubs, Cruisers and Clippers were beginning to look more than a little dated.
This was the start of the Space Age: Russia had a satellite in orbit, nuclear-powered submarines and jet airliners were being tested, and even cars (such as the Chevrolet Bel Air and Ford Thunderbird) looked futuristic. Of more interest to Piper Aircraft dealers, Beechcraft’s V-35 Bonanza had been selling strongly for ten years and they had nothing even remotely like it. If they were to stay in business, Piper clearly needed to update its product line and offer something a little more sophisticated than the ‘rag ’n’ tube’ taildraggers the company had become synonymous with.
Luckily, the previous year Howard ‘Pug’ Piper had assembled a team of engineers to design a ‘Bonanza-beater’ and had begun work on an all-metal, retractable undercarriage four-seater that would make the best use of recent advances in drag reduction, such as laminar-flow aerofoils and stabilators. This project became the PA-24.
The prototype first flew in 1956, and the first production aircraft the following year. Christened Comanche, this fine-looking flying machine is arguably the most aesthetically pleasing of all Piper’s products, and was an almost immediate success. I say almost immediate because early models only had 180hp engines and were a little gutless.
However, upon the prompt introduction of a 250hp version the following year, the Comanche really took off (both literally and figuratively). Competitively priced at around $21,000, (some $8,000 less than a similarly equipped Bonanza) sales soared, and by 1963 Piper had sold almost 4,000.
The sixties were probably the golden age of GA (particularly in America), and by 1964 there were no fewer than eight different versions of the Comanche available. It remained in production for almost fifteen years and Piper eventually sold 4,857, powered by 180, 250, 260 or 400hp engines. The most popular version (and also the subject of this flight test) is the 250hp variant, with this particular 1963 example owned by Dukeries Aviation’s Mark Bonsall. Dukeries are Comanche experts, and as this is Mark’s personal aircraft you might expect it to be a little bit special−and it is.
Recently refurbished to a very high standard, it really is in quite remarkable condition. As you approach a Comanche two things are immediately apparent: it’s a very handsome aircraft, and it sits rather close to the ground. This PA-24-250 is powered by one of my favourite engines, the Lycoming IO-540. As delivered from the factory, its 250 horses were turned into thrust by a two-bladed, constant-speed propeller, but N61970 has been extensively refurbished and now features a modern three-blade Hartzell Scimitar and a fuel-injected engine.
Access to the engine is excellent, as both sides of the top half of the cowling hinge open and can also be removed very quickly. There is a small inspection hatch in the top through which the oil quantity can be checked. The fuel is carried in the wings in rubber bladders. The standard arrangement is two tanks with a combined capacity of 227 litres; N61970 also has the optional auxiliary pair, each carrying up to 56 litres.
While the main undercarriage legs are quite short−giving the aircraft its low squat−the nosewheel is relatively large (it’s actually the same size as the 600x6 main wheels). As a consequence, the Comanche does have a bit of a reputation for ‘wheelbarrowing’ - lifting off prematurely and landing nosewheel-first if not handled correctly.
The prototype featured a trailing link undercarriage but legend has it that Bill Piper deemed this arrangement to be ‘too expensive’, and went for a straight oleo (oil-damped pneumatic spring) legs instead. Although quite short, the undercarriage is relatively wide-track. It is retracted and extended electrically using pushrods, the nosewheel retracting backwards and the main wheels inwards. Cleveland hydraulic disc brakes were standard.
The wing uses a NACA 64 aerofoil, which is an early laminar-flow section. The wing features 5° of dihedral and 2° of incidence, and is mildly swept forward. The flaps are of the same slotted type fitted to most of the metal-clad Pipers, and have four positions: ‘Up’, 10°, 18° and 40°. Early Comanches used a ‘Johnson Bar’ for flap selection but by 1963 operation was electric. Pitch control is provided by an all-flying tail−aka a stabilator−instead of a fixed tailplane and elevator.
Although also common to the PA-28 series, it is somewhat unusual for an aircraft in this class and I’ve never really understood why Piper thought it a good idea. It is fitted with mass-balances and a surprisingly large anti-servo tab, while the elegantly swept back fin carries a relatively broad-chord rudder which is also fitted with dual mass-balances.
Access to the generously-sized baggage area−which can carry up to 90kg−is via a good-sized hatch on the starboard side. It is not accessible in flight, but there is a small parcel shelf behind the rear seats. However, as with most other four-seaters, if you have lots 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.
In the later PA-24-260C model the rear seats can also be removed, which greatly increases the total baggage area. Piper even offered an optional third row of (very small) seats with the 260C, but I’ve never seen a Comanche with this arrangement.
In common with many other Pipers, there is only 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 only having the one door lost any sales to Cessna (although of course the Bonanza has the same arrangement).
On the plus side, the wing-root walkway is sensibly sized, and as the trailing edge is so close to the ground no step is required. In fact, with full flap selected the flap trailing edges are very close to the ground, and it’s very obvious that ground effect could be an issue.
The cabin is quite airy−there are two windows down each side of the fuselage−and the windscreen is also quite large. As part of the refurb, the interior trim and seats have been re-covered and look very smart.
Having adjusted the seat, which offers a fair amount of movement longitudinally, I strap myself in and begin to familiarise myself with the cockpit. The straps are the typical American arrangement of lap strap and separate shoulder strap−I don’t like them.
The control yokes and rudder pedals are big, beefy units that wouldn’t look out of place in a much larger aircraft, while the instrument panel and control layout are classic 1960s Americana, and consequently have some features that are perfectly satisfactory−and others that aren’t. For example, I prefer a proper engine control quadrant and the flight instruments arranged in the classic ‘sacred six’ layout, directly in front of the pilot.
Well, the Comanche’s power controls are plungers in a non-standard arrangement (mixture on the left, throttle central and prop control right), and the flight instruments are also laid out in a non-standard pattern! Owners of older Cherokees may note that the Comanche’s mixture control is in exactly the same place as their Cherokee’s carb heat plunger−this has probably given a few pilots a thrill over the years.
The undercarriage selector is logically placed and the flap lever, fuel valve and parking brake are all easy to see and reach. The parking brake initially doubled as the brake lever, but toe brakes became standard from 1961. On the downside, some of the switches are hidden by the pilot’s control yoke, the elevator trim winder and pitch trim indicator are in the roof, and the flap selector and rudder trim wheel are to the right of the engine controls−and a bit of a stretch.
A telescopic lever between the seats, topped with a large red knob, operates the emergency undercarriage system. The engine instrumentation is all on the right side of the panel and consists of a tachometer and manifold pressure gauge, a large fuel flow meter and a block of several small oblong dials, as used in many other Piper aircraft. There’s only one fuel gauge; to see the quantity in any given tank simply press the appropriate button around the fuel valve. It’s interesting to compare the Comanche’s ergonomics with a modern aircraft. For example, there’s a stall annunciator light (these day stall systems are primarily audible) and only two lights for the undercarriage (up or locked).
Finally, the large rotary fuel selector has five positions (including Off) but no detents or safety catch. Consequently ‘Off’ can be selected inadvertently. One old-fashioned feature that certainly did meet with my approval is that the pilot has a direct vision panel.
Taxying out to Runway 24
The injected engine starts easily and, with instructor Nick Riddin in the other seat, I taxi out to Runway 24. Nosewheel steering is via rods that are linked to the rudder pedals and these, combined with the toe brakes, make the Comanche a very simple aircraft to taxi. The field of view over, and either side of the nose is fine, but the ride is a little ‘twitchy’ longitudinally−probably because the wheelbase is quite short.
Having changed tanks to ensure both mains are feeding correctly, we complete the engine run-up and pre-takeoff checks. (Usefully, the takeoff and landing checklists are printed on the panel.) Piper recommends using 18° of flap (the second notch) for short-field operations, which seems like a lot to me. Pitch trim should be neutral, with just a little bit of right rudder trim dialled in; it works by altering the tension of springs attached to the rudder pedals.
All checks complete, I roll out onto the runway and open the throttle up to 2,575rpm. Ambient conditions are an OAT of 18°C and a light south-westerly wind while, with two on board, no baggage and half fuel we are probably around 350kg below maximum weight. Consequently the acceleration is excellent, and almost immediately I can sense the weight transferring from the wheels to the wings. Because the type has a reputation for wheelbarrowing, I add just a little bit of back-pressure to keep the weight off the nosewheel.
The Comanche hits a bump and sort of waffles into the air in ground effect, however the engine is pulling like a train and within seconds the needle of the ASI sweeps past 80kt and I ease the control yoke back, having used about two-thirds of the 500m grass Runway 24, which has a slight upslope.
With the undercarriage and flaps retracted, I pitch and trim for 90kt and the VSI soon shows a very healthy 1,500fpm. At 1,000ft I pull the power back to ‘25 squared’ (25in manifold pressure and 2,500rpm) and trim for the cruise-climb speed of 120kt.
Once level at 3,000ft, I make a further power reduction to the recommended economy cruise setting of 22in mp and 2,400rpm (55%). Initially, the speed is a little disappointing, so Nick recommends climbing above our target altitude, and then accelerating in a shallow dive, before levelling out.
This works well, and even after we’ve been straight and level for at least a minute, the ASI needle continues to creep around the dial, before eventually settling on 142kt. This gives us a TAS of 150kt for a fuel flow of around 40 lit/hr−pretty impressive for a four-seater designed in the 1950s (and, incidentally, better than the Arrow which replaced it!)
Speaking of it being a four-seater, in the interests of accuracy it should be pointed out that, although the Comanche’s optimum range with maximum fuel is over 1,100nm, it obviously isn’t possible to fill the tanks and the seats−even with no baggage. To be fair, the same can be said of practically all aircraft in this class, and it is irrefutable that the optional tanks make the Comanche is an incredibly versatile tourer.
An examination of the general handling characteristics, along with a qualitative assessment of the stability and control, reveals again that−as often happens in aviation−things have gone backward. The PA-24’s handling is much nicer than any of the later PA-28 variants, with crisp, assertive ailerons, an effective stabilator and powerful rudder. Furthermore, all the primary controls are nicely weighted and well harmonised, with low breakout forces. Basically, it’s a nice aircraft to fly.
The aeroplane is quite clean aerodynamically, and if you do let the nose dip below the horizon it accelerates quickly. Even with our forward C of G the longitudinal stability is just barely positive, while laterally it is neutral, and directionally it’s positive.
The ride quality is more like that of a light twin, courtesy of the relatively high wing-loading and, when compared to its contemporaries, the field of view is adequate−although it is certainly not up to the standard of some modern aircraft. Slowing down for an examination of its slow flight and stall characteristics reveals the Comanche to be essentially viceless.
Another trait that 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 pretty innocuous, with good buffet and little tendency to drop a wing. Indeed, with full flap and a bit of power, the aircraft was stalling at around fifty knots, which is pretty respectable for an aircraft in this class.
Back in the circuit at Netherthorpe
I reduce speed to 100kt, lower the undercarriage and then drop the first stage of flap. The undercarriage can be extended at up to 130kt (making it useful as an emergency airbrake), while the limiting flap speed for full flap is 108kt. Both flap and undercarriage selections produce only small changes in pitch, which are easily trimmed out.
As the wheels lock into place there’s subtle pitch down and a definite braking effect. Once trimmed, the aircraft is nicely speed-stable; a facet I appreciate as, with an available landing distance of around 400m, Netherthorpe is not overly long. I lower the rest of the flap as required, although in order to keep the noise down I delay pushing the prop lever fully forward until short final.
As we’re quite light, 70kt over the fence feels about right, and as the aircraft enters ground effect you can definitely feel it. Mindful of the relatively large nosewheel I take care to hold off fully, and after a brief float the Comanche settles nicely onto the main wheels. It’s a perfectly acceptable landing (and the next two are even better) but I can sense that the Comanche would be quite intolerant of poor technique.
Unlike a Cruiser or Clipper (the sort of aircraft a potential Comanche purchaser might’ve traded up from back in the day), it will not accept being ten or even five knots fast at the threshold. A protracted float is guaranteed as that laminar-flow wing enters ground effect, and any attempt to force the aircraft onto the ground may well cause it to wheelbarrow.
This is an aeroplane for pilots, not drivers. An hour later and Nick and I are aloft in the Comanche again, and easing into formation with a Cessna 172 carrying Keith and Phoenix Flying School CFI Mick Lee. I’ve written before that formation flight often shows another side to an aircraft’s character, and so it was with the Comanche.
Despite the air being fairly smooth it was quite hard work putting the aircraft exactly where Keith wanted it, and I regret sitting in the left seat as the field of view isn’t great when in echelon port. However, this should not be construed as a criticism of the type−after all Pug Piper did not design it for formation work, he designed it as a tourer.
As with any aircraft, the Comanche can only be fairly appraised when it is being operated in the role for which it was designed, and even by 21st Century standards, it is a very good tourer indeed. It has the ability to carry a fairly useful load over an equally reasonable range, and can easily fly two couples plus some baggage about 500nm, plus IFR reserve. Alternatively, it can carry two people over 1,100nm, putting most of Western Europe within un-refuelled range.
In conclusion, the Comanche 250 is a remarkable aeroplane and, when measured by the standards of the time, its performance and comfort must have been amazing to a pilot converting from a Tri-Pacer or Vagabond. Even by 2017 standards it’s a pretty impressive machine, so why isn’t it in production today, particularly when the Bonanza still is?
The Lock Haven plant was badly flooded in June 1972, when the Susquehana River burst its banks in the wake of Hurricane Agnes. But although this disaster is often cited as the reason for Piper ceasing production of both the Comanche and PA-30 Twin Comanche (as all the tooling was destroyed), it’s generally accepted that the company was already planning to stop building both types even before the flood.
Basically, the Comanche was expensive to build, having a relatively high parts count and also being labour-intensive (rivets on a laminar-flow wing require quality workmanship), particularly when compared to the aircraft that replaced it: the PA-28R Cherokee Arrow and PA-32R Cherokee Lance.
Furthermore, being cheaper than the Bonanza proved to be not only a blessing but a curse as well, as the Comanche inevitably became known as ‘the poor man’s Bonanza’. Finally, the Comanche was never quite as fast as the Bonanza, primarily because the Beechcraft had a 285hp Continental. Piper favoured Lycoming engines and Lycoming didn’t make one that powerful!
The Comanche was used for many record-breaking flights. In 1959 Max Conrad flew his PA-24-180 from Casablanca to Los Angeles, in an incredible flight of 7,668 miles. It took over 58 hours, and at takeoff weighed almost double the approved MAUW of 2,268kg as it carried 1,968 litres of fuel! Five years later Henry Ohye flew a 250hp version across the Pacific from America to Japan, and in 1966 Britain’s Sheila Scott flew her 260-B model Myth Too solo (in the accepted use of that word, other female aviators may note) around the world, in a flight of almost 30,000 miles, setting many records in the process. A Comanche-400 fitted with a Garret turboprop engine also set an altitude class record of over 41,000ft in 1968.
SPEC:Piper PA-24-250 Comanche
Wing Area: 16.53 sq m
Weights and Loadings:
Empty weight: 766kg
Max AUW: 1,315kg
Useful load: 549kg
Wing loading: 79.6kg/sq m
Power loading: 7.06kg/kW
Fuel capacity: 39 lit
Baggage capacity: 90kg
Cruise (TAS): 157kt
Climb rate: 1,350fpm
Service ceiling: 20,000ft
Engine: Lycoming IO-540- air-cooled flat six, producing 250hp (186kW), driving a Hartzell Scimitar three-blade constant-speed propeller
Manufacturer: Piper Aircraft Co.