A huge, military-influenced four-seater with comfort, fine handling and what has to be the world’s fastest-extending undercarriage. Words Dave Unwin, photos Keith Wilson
Three satisfyingly positive clicks on the elevator trim wheel and the ASI’s needle seems painted onto the dial’s glass face. It almost feels as if the Navion is on rails as it slides down the slope towards the waiting runway. This really is a fine-handling flying machine!
The test aircraft, N3864 is, to give it its correct designation, a ‘NAvion’ B, built by Ryan in 1951, and owned by Mick Manders and Cavendish Aviation’s Steve Allen. I meet it on a beautiful September morning at Cavendish’s Earls Colne base and my initial impression is that, for a four-seat single, it’s enormous. At 2.6m to the top of the tall fin, it towers over similar types.
If you like your aircraft to have ‘ramp presence’ you’ll love a Navion! ‘November six four’ was completely rebuilt by renowned restorer Gordon Spooner several years ago, and for a 67-year old aeroplane it is in fantastic condition?and an excellent advert for Cavendish’s Aerocoat process (a nano coating developed by Cavendish?see TB-10 flight test, Pilot October 2016 for a full description). It really does look great.
The Navion was the first foray into the civilian market by North American Aviation (hence the NA in NAvion) and it is immediately apparent some military thinking has been carried across. Basically, this thing was built to a specification, not a price.
For example, the large welded steel strut in front of the port wing root carries a step covered with diamond pattern deck plate that wouldn’t look out of place in the cab of the Flying Scotsman! Another nice touch is that the landing and taxi lights mounted in the bottom half of the cowling have ‘eyelids’. (As delivered from the factory in 1951, the landing and taxi lights were on the undercarriage legs and the nosebowl a very different shape.)
Another ‘Mil.Spec’ feature that I like (being an aviator of the old school) is that the cowling hinges open good and wide on both sides of the engine and is held up by rigid stays. There is an increasing tendency for modern aircraft to be quite tightly cowled and only offer barely adequate access to the oil dipstick.
Well, call me a bluff old traditionalist but I quite like to have a good poke around before flight, and have pulled enough bird’s nests out of engine bays to justify my caution! And as we’ve got the cowlings open, this is a convenient point to mention the engine. The original 260hp Lycoming has been replaced with a 285hp Continental IO-520 air-cooled flat-six turning a three-blade constant-speed McCauley propeller.
Unusually, it isn’t suspended from a conventional welded steel-tube engine mount. Instead, the mount is made as part of the lower fuselage.
Fuel is carried in a single 150 litre tank and a pair of ‘Tuna’-type tip tanks which can carry an extra 75 litres each. On N64 these are an aftermarket item produced by J L Osborne Inc and were not standard equipment. Some late-model Navions had 128 litre tip tanks and were called ‘Rangemasters’: with 406 litres of fuel available it’s not hard to see why!
The wing has approximately seven degrees of dihedral and is unusual in that?being of monococque construction?it doesn’t have a main spar. Instead the thick wing skins are carried by a plethora of ribs and stringers, while the main undercarriage legs are located on stub spars.
The wing uses two rather old-fashioned aerofoil sections (they join approximately 1.2m outboard of the wing root) and therefore is quite thick, with large stall strips in front of the main undercarriage legs. The big hydraulically-actuated flaps are infinitely variable between 0 and 40 degrees, and there’s a ground adjustable trim tab in the starboard aileron.
In common with the rest of the aircraft, the short wheelbase, wide-track undercarriage is sturdy and well made. Interestingly, as NAA were big on furnace brazing, the undercarriage (and several other components) were originally constructed using this technique.
However, once all the NAA-produced parts had been used up, later models were welded, not brazed. Along with the B model’s stronger, welded undercarriage the tip tanks’ Supplemental Type Certificate allowed an increase in the original max all-up weight from 1,294kg to 1,409.
The undercarriage is actuated by an unusual combination of hydraulics and powerful compression springs. During extension, these coil springs force the undercarriage down very quickly, aided by the hydraulic system. On the retraction cycle, just before the hydraulics raise the undercarriage completely, the linkage goes over-centre and the spring action is reversed to add a bit of ‘up’ pressure, helping the mainwheels retract inwards into the wings and the steerable nosewheel aft into the fuselage.
Check out these other flight tests:
The latter connects to the rudder when the undercarriage locks down. None of the wheels is covered when retracted (in fact the nosewheel is slightly proud); small doors cover the main undercarriage legs.
Aft of the port wing root is a very large door to an equally big baggage bay behind the rear seats. Accessible in flight, it can carry almost 82kg but, in a rare design flaw, you cannot latch the door open with its stay when the canopy is fully back.
I was intrigued to spot a couple of sandbags in the baggage bay; as Steve typically only flies it with two POB, these are a simple way to keep the centre of gravity from moving too far forward. One further fascinating feature is the small aft-facing ducts in the wing roots to extract cabin air.
The Navion is sometimes referred to as the ‘poor man’s Mustang’, and the wings, fin and tailplane do look rather P-51-ish, particularly as the mildly swept-back fin has a dorsal fillet in front of it, while the tip tanks are strongly reminiscent of the Cavalier F-51D.
According to NAA’s brochure ‘the fact that the NAvion looks like a Mustang is incidental to its design. There was no studied attempt to make the new plane resemble a Mustang. The configuration and aerodynamic qualities of the tailgroup and wings, which make it resemble a Mustang, proved beyond a shadow of doubt during long military service that they were the best from the standpoint performance and handling qualities’.
However, NAA may have been a bit disingenuous here, as the sales brochure also claims that ‘but for the fact that the NAvion was designed for the flying public, it is a military airplane’ and that ‘pilots used to flying military airplanes may find the NAvion a closer counterpart to the fine airplanes produced for the armed services than any other personal airplane on the market’.
There’s nothing like a little brand loyalty, and there were a lot of B-25, P-51 and T-6 pilots out there – although, as it would transpire, not necessarily in the market for an aeroplane.
The tailplane is also of monococque construction and carries a mass-balanced two-piece elevator with big, cable-operated trim tabs in both sides. The rudder trim tab is only ground adjustable, and I was slightly surprised by this, but Steve assured me it was adequate.
Getting in is, in my experience of this class of aircraft, unique. Having climbed up onto the port wingroot walkway (which is so high that you would not want to fall off) you slide the giant canopy aft, step onto the floor between the front and back seats, then walk to the front. All well and good, unless it’s raining!
The cabin is luxurious, with lots of room and comfortable leather seats. It very much reminded me of a luxury American car from the ’fifties. Even the lever in the roof which operates the fresh air scoop is beautifully made. All very interesting, but not as interesting as the pilot’s seat. This is as sumptuous as the passenger seats and offers a good range of adjustment both longitudinally and vertically.
There are only brakes on the P1’s side (originally the aircraft just had a lever that applied braking to both wheels simultaneously) and, despite the ‘Ryan’ data plate beneath the fin, the P2’s rudder pedals are embossed with NAA’s logo. The comfortable control yoke is?by modern standards?bereft of buttons.
Although the panel is primarily analogue, it is so large and well-designed that it offers a very uncluttered look. The primary flight instruments are located directly in front of the pilot in the classic ‘sacred six’ layout, with the usual engine gauges on the right and the avionics in the middle.
There’s a separate fuel gauge and L/R selector switch for the tip tanks, while the rest of the electrics are controlled by a row of robust toggle switches. The fuses (and some spares) are carried in a neat fold-out panel.
An interesting feature is the large hydraulic pressure gauge which is quite prominently located right in the centre of the panel. The hydraulics are like the ‘power-push’ system fitted to the T-6 Harvard, but are different in that they must be turned off manually. It is important to do this as the system runs at 1,175psi, and if you forget you’ll knacker the seals.
It is controlled by one of several large silver plungers that sprout from the panel; the other, identical plungers operate the park brake, cowl flap and emergency hydraulic valve, the emergency hydraulic hand pump being sited beneath the panel. The fuel selector is mounted on the floor.
Note that the operating plunger doesn’t turn on the hydraulic pump (it runs continuously). When the plunger is pulled, the system builds up pressure by restricting the return flow (a bit like a temporary pressure relief valve). Push the plunger back in and the system free-flows. It is good practice to leave the hydraulics ‘on’ all the time the aircraft is on the ground.
This keeps positive ‘down’ pressure in the system and guards against the undercarriage accidentally retracting after hitting a bump or rough ground.
Vernier plungers are used for all the power controls, with the undercarriage selector, flap switch, pitch trim wheel and indicator all to the throttle’s left. The undercarriage and flap selectors are a little too close together by modern ergonomic standards, but they are very different shapes and the undercarriage selector also incorporates a safety catch.
A couple more flight tests:
Growls into life instantly
The big Continental growls into life instantly, and just a hint of power nudges us out of our parking space. This is a fine machine to taxi, with smooth, progressive brakes and positive nosewheel steering, and as you sit so high up the field of view is excellent.
Pre-takeoff checks are standard: the pitch trim indicator is on the panel next to the serrated trim wheel, while a line painted on the port flap shows when 20° (takeoff flap) is set.
With the main tank half full, empty tip tanks and no baggage, we are some 200kg below the 1,409kg maximum all-up weight. The ambient conditions are better than ISA as, although Earls Colne is 227ft AMSL, it is a cool, crisp morning, with only a slight crosswind.
Even though I bring the power in deliberately slowly the acceleration is excellent, with only small inputs of right rudder required to track the centreline, and as the needle of the ASI sweeps rapidly through sixty knots, a hint of back pressure lifts the nosewheel off the runway, followed swiftly by the main wheels after about 200 metres. A quick dab on the toe brakes stops the still-spinning wheels, then I fumble with the safety catch and pull the undercarriage selector out slightly, then up.
The undercarriage retracts very quickly, and with speed building nicely I stow the flaps, push the hydraulics plunger back in and set off after the C182 camera ship. Best rate of climb is eighty knots, but even climbing at 100 for improved visibility still has the VSI indicating around 1,200 feet per minute.
It’s a glorious morning for flying. The last of the mist is still burning off and the air is completely calm as we head out over the River Blackwater. Vernier throttles and close formation work don’t really mix, but the air is so smooth and the handling so precise that we soon get a fine set of pictures in the can.
Photographer Keith wants some shots of the undercarriage cycling, so I close up and ask Steve to lower the wheels. The powerful spring/hydraulic system seems to practically shoot the wheels down. There are very definite ‘thumps’ through the airframe as the legs lock into place and later, when we are back on the ground, Keith confirms he’s never seen an undercarriage extend so fast.
Photoshoot complete, I fly parallel with the coastline and examine the control and stability more closely. I always like to start my exploration of a new type’s handling with a couple of steep 360 degree turns in both directions, and the combination of excellent visibility and simply superb handling make these manoeuvres a joy to perform.
In fact, the handling is so precise that I manage to hit our wake on only the second attempt. The big, wraparound windscreen provides an excellent field of view and, as Steve had predicted, I do not notice the absence of rudder trim. Particularly worthy of comment is the elevator trim; it’s geared just about right, and I love the nice positive ‘clicks’ as its serrated wheel is adjusted. This really is one of the best pitch trimmers I’ve ever handled.
Harmony of control is outstanding, with relatively light, authoritative ailerons, a well-damped, slightly heavier elevator, and a rudder that is powerful without being too heavy. I suppose the people at NAA had plenty of time to get the stability and control right, and it shows. In many ways the ride is more reminiscent of flying a light twin. I’m slightly surprised at how little rudder is needed even when turning quite tightly, and wonder if perhaps there is some kind of spring-interconnect system between the rudder and ailerons. (I subsequently learned that there is.)
An examination of the stick-free stability reveals it to be positively stable directionally, just barely neutral laterally and positive longitudinally, with the aircraft returning to its trimmed speed from a ten-knot displacement at 120 after only two long-wavelength, low-amplitude phugoids.
Slowing down to explore the stall proves very interesting?for such a big machine the stalling speeds are really low. Flaps up, it quits flying at about 65kt, while a full flap stall occurs at around an impressively low 45kt.
There isn’t a stall warner fitted but there’s plenty of buffet either flaps up or down which gets increasingly insistent as the alpha increases. It’s interesting to note that the ailerons remain effective even when the wing is stalled, while the aeroplane also has a tendency to roll itself ‘wings level’. Even a departure stall is a complete non-event.
The stall with flaps and undercarriage down gives me the chance to examine the undercarriage extension time more closely and it really is very quick. You power up the hydraulics, check the pressure, select ‘undercarriage down’ and almost instantly feel very definite ‘thumps’ through the airframe as the legs lock into place. I’ve never seen ‘three greens’ light up so quickly! Retracting or extending the undercarriage only produces very subtle changes in pitch trim, but there’s a big change with full flap.
Accelerating out of the final stall I select flaps and undercarriage ‘up’, climb swiftly to 4,000 feet and set the aircraft up with Steve’s recommended cruise power setting of 21 inches of manifold pressure and 2,300rpm. The ASI eventually settles on 123kt for a TAS of 131 while burning around 45 lph. It will go faster but burns a lot more fuel in the process. A TAS of 150 at 6,000ft will consume nearer 60 lph.
Heading back to Earls Colne in a gentle cruise descent with the big motor rumbling quietly and the Navion lazily loping along as solid as a rock, I suddenly realise what the Navion reminds me of – the 1978 Lincoln Continental I drove while living in California.
Back in the circuit, the Navion is very speed-stable and the best way to fly it in such smooth conditions is just to hold the control yoke gently between thumb and forefinger and practically fly it on the trimmer. As mentioned earlier there’s no flap position indicator so, having powered up the hydraulics and checked the pressure gauge, I look over my left shoulder for the line painted on the flap. With practice, I’d probably just count “one potato, two potato” or do it purely by feel.
About seventy knots on final feels right, bleeding back to sixty over the fence while carrying a little power. My experiments at altitude had convinced me that, with full flap selected, a suggestion of power all the way into the flare was the way to go, as full flap creates a lot of drag.
On the first approach all looked good, but I’d forgotten just how high up the pilot’s seat is when compared to similar types such as the Bonanza or Comanche. Consequently, I was just starting to feel for the ground when the ground felt for me. It wasn’t bad but it wasn’t good either, as the wheels met the ground slightly earlier than intended.
Full power, rotate, positive rate, gear up. This time I remember the safety catch and have the flaps and wheels stowed and the hydraulics off as if I’d been flying Navions for years. This may sound odd, but you know how with some types you sense that, although an aircraft is not yet your servant, you’re not quite its master? Well, it seemed to me that N64 wanted to be my friend. It’s very well mannered.
Confidence fully up, as we pass abeam the threshold I engage the hydraulics, lower the undercarriage – thump, thump, thump – and then drop a bit of flap. This time I wait a little longer before selecting full flap, then slowly draw the throttle almost all the way back, pause and then add just a pinch of power. I’m rewarded with a real ‘squeaker’, and still make the first turn off with minimal braking, even though there’s practically no wind.
I really liked the Navion. It’s a solid, steady performer, that can carry a good load a short distance or a smaller load a long way. It’s clearly from a time when gas was 25 cents a US gallon, and it’s irrefutable than many aircraft do more on less. Yet it has tremendous charm, good handling, is very comfortable and of course has immense ramp presence.
And if you can afford the fuel, one significant advantage is that with up to 300 litres to play with you don’t have to stop so often to refuel, so a long trip can actually be quicker overall. Yes, it’s not as fast as the Cirrus SR22 or Cessna TTx (both of which I’ve tested recently for Pilot) but it’s certainly as comfortable. It’s also a bit of a bargain. A new SR22 or TTx costs serious money, and the difference between a new G6 or TTx and a restored Navion would buy a lot of avgas!
As we walked away Steve confided that “the Navion is the only aircraft my wife likes flying in” – and that pretty well sums it up.
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