Sunday, 26 May 2013 23:25
The Perfect Plane: Our Better-Than-New Cessna 170B FeaturedWritten by John Nielsen
When you begin the search for the aircraft model that will best fit your most common mission profile, you define and prioritize the wants and needs that will fit into a defined budget.
You evaluate necessary compromises, and debate between two-place or four-place; speed; cargo capacity; VFR or IFR. Will the airplane be used on unimproved strips or paved runways? Then come the costs to acquire, operate, maintain and insure your choice.
The Light Sport category of new aircraft gives a pilot several possibilities, but most are small two-place aircraft and still run well in excess of $100,000. When one looks into purchasing a new Normal Standard category aircraft, they quickly discover that requires an even larger investment.
The Perfect Plane
Like most pilots, I learned to fly in a Cessna 152 then transitioned to an old 172 line rental plane. The first plane I owned was a 1947 Cessna 140 with an 85 hp engine. It worked perfectly for getting out and enjoying the freedom of flight with a very small cost to operate.
When my daughter began to accompany us, I sold the 140 and bought a 1948 Cessna 170. Everybody in the family loved this plane. The high wings and low panel allowed for great visibility. It had a huge cabin and could carry nearly 1,000 pounds into the air with ease.
When our daughter left for college, I thought it might be a perfect time to take my wife on some long cross-country trips for sightseeing and visiting friends scattered around the country. The C170 could carry all the baggage we wanted to bring, but it was slow enough that diverting for weather meant changing plans for lodging and fuel.
I sold the 170 and purchased a Vans RV-6. At 186 mph TAS, the RV-6 was fast enough that a deviation for weather only added a few minutes to a trip leg and never resulted in revisions to fuel or lodging. You could easily go 1,000 miles a day on 55 gallons of fuel.
In my RV-6, I could make a solo trip from Minneapolis down through New Mexico and up to Sacramento, Calif. in only 12 hours of flight time. The downside to this plane was the much smaller cabin and reduced visibility. After a few trips together, it was clear we wanted visibility and space more than speed.
Time to change planes again. If only a 170 could be a bit faster and have a modern panel like my RV-6…
It can! There are over a hundred STCs that apply to the C170 which will allow a pilot/owner to customize it to their exact mission profile.
I wanted a four-place plane with large cargo area that I could use to transport the guitars and amps I often bring along to fly-ins and camping fly-outs. My wife loved the visibility of the 170 because of the low panel and high wings. The doors are large and even removable for large loads. The seats are also removable for accommodating bulky cargo, and the load capacity and short-field performance is spectacular.
A project between friends
A friend of mine since childhood has a wonderful habit of buying planes and old cars, and he enjoys rebuilding them. He is a masterful technician who is as comfortable with a rivet gun and sheet metal brake as the rest of us are with a television remote control. His impeccable work quality is recognized by the local FSDO and he has successfully adapted many modern features into old planes by way of field approvals.
Kris purchased a 1955 Cessna 170B a few years back with the intention of making it like-new with lots of mods you would want if you were designing the plane today. The plane was clean, with no damage history and had recently had a Sportsman STOL kit installed to the wings. He’d already purchased a 65-hour TTSN Lycoming O-360 engine and the STC to install it.
I asked Kris if I could buy this project and assist with the restoration. He agreed as he already owned several planes and liked the idea that the aircraft would stay local and with someone he knew.
The basic starting aircraft
We began our project with an undamaged 1955 Cessna 170B. The B model was deliberately selected because it has the best wing design of the three 170 versions.
It has the largest ailerons and big Fowler-style flaps that are adjusted quickly and easily with a convenient single lever between the seats. The B also re-routes control cables to the subfloor, making a clean useful load area.
And because it was certified under Civil Air Regulations (CAR) Part 3, it is much easier to get modifications done and approved.
The stock engine is a six-cylinder Continental O-300 with 145 hp. There are several STCs that provide for the upgrade of the engine to the four-cylinder Lycoming 360 series that makes between 180 and 210 hp. We chose Del-Aire’s STC. The weight of the two engines is about the same, and the extra power is a real bonus.
We took that Lycoming O-360-A2D with only 65 TTSN and replaced the “shower of spark” mags with new Bendix dual impulse coupling mags. This allows for hand-starts even with zero battery voltage.
The starter motor and alternator were changed to B&C, and an MT compact propeller governor was installed to save weight. A spin-on oil filter adapter was also added along with a Brackett air filter.
The intake and exhaust ports were polished to aid in airflow. The exhaust system uses header pipes with no restrictions to the heat muff collector and large diameter outlet.
The engine was dressed up by adding a bit of bling. The paint we used is Lycoming Grey with a bit of hardener added for shine. The baffles were painted black before installation. Push rod tubes, rocker covers and intake risers were chrome plated. Copper lines and brass fittings all received a good polish before installation.
A 79-inch MT Composite three-blade constant-speed propeller from Flight Resource was selected to harness the engine horsepower and turn it into thrust. The MT prop is lighter than the fixed-pitch prop and allows the pilot to use the full power of the engine at takeoff and set for low rpm for economy cruise.
The composite blades tame and absorb the notoriously strong firing pulses of the 360 series engine, and the prop has stainless steel leading edges for unlimited life and durability. It provides the highest static thrust of any propeller available for this engine.
A Sportsman STOL kit had already been added to the wings. This mod elongates and droops the leading edges of the wings a bit which results in a lower stall speed and improved low-speed handling without the penalty in cruise speed.
Gap seals are then added to both the flaps and ailerons to further control airflow and reduce drag. The wingtips are changed to a molded Horton style that also aids lift by controlling air moving out and away from the wing.
The wings, flaps, ailerons and tail section interiors were all washed and painted with zinc chromate before installation.
Landing gear, wheels and brakes
The stock gear Cessna installed on the 1955 C170B is nearly perfect. It is a bit stiffer than earlier years and has a nice-looking shape. We installed a gearbox reinforcement kit from P Ponk as well.
The plane will be equipped with Federal AWB hydraulic wheel skis, so the stub axles and brackets were fitted at this time. New Cleveland wheels with dual cylinder brakes were installed that allow for the use of tires up to 32 inches to be stopped with ease. Of course, all brake lines are new and the master brake cylinders were rebuilt as well. It will be fitted with 8.00 tires to begin with.
The goal is to make this a strong, lightweight four-place plane that can carry over 1,000 pounds of fuel, cargo and passengers with ease and comfort. With the advent of active noise-canceling headsets, the need for heavy soundproofing has been eliminated.
The entire interior of this plane was stripped, zinc chromated and painted. No interior trim panels will be used. The seats were stripped of their old, heavy springs and wool padding and replaced with Ceconite bases covered with modern aircraft padding and fabrics by Sport Aircraft Seats of Wasilla, Alaska. New seat rails and seat belt systems are used, too.
Skylights were installed as in the Cessna 120 and 140 models. A baggage door from a Cessna 172 was installed along with the extended baggage STC from Selkirk Aviation. New control cables, bearings and pulleys were installed throughout. A BAS retractable tail pull handle will make our 170 easy to move around.
Because the plane will be operated on skis and the possibility of floats, a float kit from a Cessna 180 was used. This kit uses larger reinforcing doublers spreading any stress over a larger area.
A V-brace by F.Atlee Dodge will strengthen the forward cabin door frame areas.
New fuel lines were bent and installed with new AN fittings. Cowl steps and grab handles on each side will make it easy to get up to the fuel tanks or windshield without a ladder.
All the windows were replaced with new. The steel side window frames were replaced with aluminum frames from a C180—that saved 12 pounds. The hand pump and hydraulic lines for the skis will be installed between the seats.
A new panel will be cut, and only the basic instruments required by the Type Certificate will be reinstalled. The engine STC adds the need for manifold pressure and fuel pressure gauges.
A Garmin 496 in an AirGizmos mount provides GPS navigation. An electronic flight instrument system from Grand Rapids Technologies provides the means to monitor every aspect of the engine operation, fuel burn and power being produced.
The EFIS display also takes GPS data from the Garmin along with pitot and static air data and feeds from a remote magnetometer and built-in AHRS to provide a full function backup guidance and flight direction system. It even includes AOA functionality.
All original wiring was removed and will be replaced with modern Teflon coated wires. Fuses will be replaced with Klixon breaker-switches.
Wingtip strobes from Whelen Engineering will be installed to help to be seen. Interior cabin lighting will be combination of dimmable self-lit, post lamps and a light strip under the eyebrow of the panel.
A new 720-channel digital radio and King Mode C transponder is to be installed in the center so it is easy to operate from either side; ADS-B “In” will be installed at this time. A PS Engineering four-place stereo intercom with multiple aux (music) inputs makes communication and entertainment in the cabin perfect. The ELT will be changed to a new 460 MHz version.
The exterior will be finished with a full coat of DuPont Imron white, then a bit of contrasting color will be added. The entire interior is painted with a light gray U.S. military enamel. These paints cover with one coat and are both extremely durable and easy to clean.
When you look at available C170B airframes for sale for about $10,000, then add an engine, parts and labor to completely strip and rebuild the entire plane with all the options that you would want, you will end up spending between $65,000 and $125,000.
You will then have a like-new plane with a new engine, new prop, new panel, new wiring and new seats for less than half the cost of a new two-place Husky or C172. And the load capacity will be over 1,000 pounds with incredible short-field performance—and cruise speeds better than the Husky and about the same as the brand-new 172 models.
In other words, you’ll have a “better than new” airplane… for about half the price of new!
Part two will feature pictures and flight test data from the finished project.
Author’s Note: I would like to give special recognition to Daniel Maccarone of Sport Aircraft Seating for his talent in designing and fabricating seat coverings for this plane and Tom Bauer of Top Flight Avionics in Cumberland, Wis. for his detail skills in the form of the panel work and wiring.
|Del-Aire Conversions||(559) 784-9440|
|Grand Rapids Technologies||Grtavionics.com|
|Sport Aircraft Seats||SportAircraftSeats.com|
|Sportsman STOL from Stene Aviation||Steneaviation.com|
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