The home of everything related to Twin Navion and Camair aircraft
Should you consider buying a Twin Navion? Absolutely. As far as I'm concerned, they're the best bang for your buck when it comes to light twins. Don't let their "rarity"
scare you off. That's a label applied by people who don't know what they're talking about. 120 were converted in a factory, and they all use the same airframe as the single
Navion, meaning more than 3,000+ airframes to source parts from. The goal of TwinNavion.com was to dispel this myth and answer questions just like yours.
I've been asked this question before, and I thought I'd saved the response, but apparently not. I'll try to remember what I've said before, but forgive me if I send a follow
up message to fill in the blanks.
I believe you're probably considering NXXXX, a D-16A that's back up for sale. That airplane was previously owned by a doctor, and I believe it has been kept in pretty good
shape throughout its life. I haven't purchased that plane's records from the FAA yet, but there's a 50/50 chance you'll find some damage history. As a type, the Twin Navions
were either babied, or ridden hard. The ones that are left are usually the babied ones.
The first thing I try to tell people is that they have to understand a Twin Navion is not a Baron, and never will be. If you're looking for a fast plane, or something you'll
take up high, this is not the plane for you. If you want to add another 800 lbs on your Navion's gross weight and are willing to pay the extra fuel burn then you're in the
right market.
Flying:
I'm a low time pilot with only 300 hours total time. About 200 of those are in our Twin Navion, a D-16A. I literally went from flying in the flying school's Cessna 172s, to
the Twin. I had absolutely no problem with the transition. My problem was getting used to all the extra radios and instruments.
A single Navion will burn 12-18 gph based on the size of the engine installed. The Twins will burn 15-20 gph. If you're light and use lower power settings, you'll see the
bottom number. At gross weight, you'll be at the upper end. I've gotten it as high as 22 gph - don't ask. According to my father, who's flown way more planes than I, the
D-16A performs identical to a 260hp Navion (I've only flown a 225hp Navion).
Cruise is about 145 mph at 25-squared, and gross weight. Fuel burn at 20 gph. I've been trying to fly lighter to get the gph down, but I still do all my flight planning at
20 gph. Takeoff and landing performance is typical Navion - very good, better than a Bonanza. We used to take ours into the mountains and the grass strip at Banff (before the
government tried closing it). That required a one-way approach down the side of a mountain, at about 2,000fpm descent. You get that with gear and full flaps, fine pitch and
idling engines.
Navions are very stable in turbulence, and the Twins only more so, because of the higher wing loading. We've been in 45+ knot winds and had no troubles. My grandparents used
to deliver passengers to Lethbridge when the winds were too high for DC-3s to land. They simply landed the Navion right in front of the terminal. The big tail will cause
weather cocking, so watch for it and be prepared. Steering is done with the nose wheel and not differential brakes. This instills the Navion with a solid feel on the ground.
As far as twin airplanes go, the Twin Navion and Piepr Apache are as basic as you can get (I think the big tail makes the Twin Navion easier to fly than the Apache). The
engines are normally aspirated and carbureted. There's no anti-icing, no, cowl flaps, no fuel injection, no super chargers and no turbo chargers. All you have to worry about
is throttling back to keep the manifold pressure and keeping the propeller rpms under the red line. Out here in Alberta, I don't even have to worry about the MP. I'm too high.
My last flight, was the first time in two years I had to throttle back after takeoff, and that's because I was flying in Saskatchewan.
Single engine performance is quite unexciting. Because the plane has such a large vertical fin and rudder there's effectively no critical engine. You just overpower it.
Stalls are predictable and straight forward. There's a noticeable buffet before, the then the stall. The outer wing keeps flying, and you can maintain aileron effectiveness.
I had a chance to fly a Beech 18 and it was almost identical for numbers (except the engines). Not that everyone's flown a Beech. The ailerons are heavier than any Cessna or
Piper I've flown, and it gives the Navion a "big airplane" feel. Elevator is only slightly heavier than in other planes, but much less than an Aztec, and the rudder is
interconnected with the ailerons to help co-ordinate your turns. I flew an Ercoupe, which is the pinnacle of this system, and I thought the Navion had better co-ordination. I
really believe that if you killed yourself in a Navion, you did something to deserve it, and you would have been dead a lot quicker in something faster, or more high-tech.
Looking at the accident reports supports this. Most crashes were caused by fuel mismanagement, or flying into IFR conditions.
I talked with the chief designer at TEMCO about the work they'd done to upgrade the D-16 into the D-16A. The whole goal was to create a single engine service ceiling of 5,000
feet ASL. They started at 4,000 lbs and removed weight until they got there - at 3,600 lbs. Recently my father was doing his IFR check ride. They were easily at gross weight
out here in the foothills of the Rocky Mountains, at about 6,000 feet ASL. They pulled one engine back to zero thrust (simulated engine failure) at 13" MP. They then continued
to fly in simulated engine out conditions for another 45 minutes - without loosing altitude. Thinking about it later, my father discovered that they'd also been using the older
engine, approximately 500 SMOH. With 5,000 hours in 200+ aircraft types, it was something that really impressed him, and he still tells people about what his old girl can still
do.
I mentioned the weight experiments, because with the two baggage compartments, four seats and five fuel tanks, its easy to overload the D-16A. As long as you take off in the
fore/aft limits of the C of G envelope, you'll be okay. All of the fuel tanks are on the C of G, so as fuel burns, it descends straight down, into the legal envelope. I try
not to exceed this, but I have been above it. The worst I've heard of was an 800 lb overload. It used up a lot of runway and struggled for a long time before it burnt off
about 400 lbs of gas. Then it started to pick up and behave. We typically keep the main tank full and run with 15 to 20 gallons in the nacelle tanks to give flexibility. We
only put fuel in tips if we're going to burn it off right away.
Landing gear and flaps are hydraulically actuated. This can scare people away, but that's only because they're used to electrics. I've only had one problem with the system in
11 years. I was practicing emergency gear drops at the time and that's when the pump decided that it wanted to die. No big deal. We flew back home with the gear down, taking
about 45 minutes to do so, and did a flapless landing. Had the gear been up, I would have flown home and simply dropped the gear using the emergency release, which pulls the
uplock hooks. I could have pumped them up or dropped the flaps using the emergency hydraulic pump, but I didn't bother.
Maintenance:
Once again, the plane's simplicity becomes a great strength.
The engines behave just like any other Lycoming engine (although I'll make some comments later).
The airframe is bullet proof. Navions were overbuilt and as a result they keep on going when their contemporaries are getting tired. You'll have a hard time finding a 1955
Apache that isn't worn out, but the Navions just keep on trucking along. Just don't forget they are 60 year old machines and have a really good pre-inspection done. We do
preventative, on-going maintenance on our plane. The annual usually only takes one day and that's mostly because our AME likes doing pressure tests on the cylinders. We
typically keep a couple thousand dollars for those problems that creep up throughout the year, and another couple for one or two specific tasks. In that way we've installed a
new windshield, rebuilt the nose gear, and removed, stripped, inspected and repainted the ailerons and flaps. Main gear are probably the next ones we'll tackle, but its hard
without a hangar.
Twin Navions have their own type certificate, so we're not immediately connected with ADs against the single Navions. Recently there was a huge battle over the Navion's fuel
selector. Many argued it wasn't warranted. No D-16, D-16A or Camair is affected by this AD. Off the top of my head, there are no structural ADs against the type. There was
an AD against the propellers a couple years ago. Make sure this has been done before you buy. It was against the Hartzell blade clamps and affected tens of thousands of light
planes.
Maintenance of the Navion is simple and straight forward. Maintain per the single Navion manuals, except for the Twin's supplements. Airframe parts are available for almost
everything, except the fluted aileron and flap skins. I've seen photographs of one Navion with a traditional built-up flap with flat skins, but I hope the owners of the Navion
type certificate decide to start producing new skins soon.
The Lycoming O-340-A1A engines are the only down fall of the D-16A. They're an odd-ball, built in low numbers before the O-360 started. That's not to say they're bad. No. It
does mean that you should keep your eyes and ears open for parts though. In the last ten years, we've picked up three spare engines. One from an STC'd Cessna 170 that the
owner was changing to an O-360, and two from an STC'd Apache that was being parted out. In both cases the owners asked our local engine shop if they knew anyone interested, and
they passed the word to us. I won't tell you what we paid, but all three were less than an overhaul. Many people are scared away because they think its impossible to get
parts. Its not impossible, you just need forward thinking.
Back in 1975, when my father was rebuilding our plane, he wanted to upgrade to O-360s. At the time, Transport Canada allowed you a 5% hp increase without paperwork. 5% of 170hp
is 8.5hp. A 180hp O-360 was 1.5hp too much, and Transport Canada wouldn't allow it. He tried arguing it but Transport Canada wouldn't budge.
Canada:
At the moment there are only two Twin Navions and one Camair in Canada. Ours is the only one flying regularly. C-FKLB and C-FDEC were in Southern Ontario for decades.
Twin Navions aren't in the Nav Canada "big book of airplanes" so we used to get all sorts of pointless clearances when flying into Calgary International. Occasionally this
resulted in 737s getting hold short orders incase we couldn't land in 2,500 feet. We tried several times to add the Twin Navion to the book, but no one knows how to do so.
Another Nav Canada quirk is flight planning. We're now NA16s in the computer, but for a while it seemed like we were getting different designators every time we took off.
Watch your landing fees too. D-16As weigh 3,600 lbs. Camairs are 3,930 or 4,323 lbs. Depending on who's looking at the book when they're billing your landing fees, you could
get a bill you'll have to argue. Medicine Hat was doing this to us for about a year.
General:
Navions in general, have been extensively modified throughout the last 60 years. And since most are American, watch the number of repairs and modifications done on FAA 337
forms. Canada doesn't accept these and you'll have to get them covered, usually via Canadian LSTC.
We whole heartedly recommend membership in the American Navion Society (Navioneers), as they have an extensive parts and maintenance network. Most of the maintenance tips for
the singles transfer directly over to the twins. You used to be able to order all their technical articles as a package.
Because Twin Navions are only four seaters, you won't run into the insurance and landing fee problems that can come with six seat Barons, Senecas, Aztecs, 310s, etc. Also,
consider that turbo chargers, super chargers, and bigger engines used on those planes will bump you to the 25-30 gph range, and add thousands to your overhaul and maintenance
costs.