The Perfect Plane: Part Two: Our 170B Project is Complete

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After two years of additional work to get her flying again, my better-than-new 170B now has over 70 hours of flight time.

April 2014-

In the first half of this two-part series ("The Perfect Plane," May 2013), I introduced this project. My goal was to take a 1955 Cessna 170B with low time and no damage history to a new place in terms of its features and trim.
The plane was recovered from near-abandonment on a ramp at a rural Pennsylvania airport. It was brought back to the Midwest with the intention of parting it out—until it was discovered this plane was ugly as sin on the outside, but pure as an angel on the inside.

The project began with the complete disassembly, cleaning, inspection and zinc chromating of the fuselage. All flying and control surfaces had the skins removed to allow for full inspection, cleaning and chromating.

My longtime friends and masterful technicians Kris and Phil installed the 180 hp engine, a Sportsman STOL kit from Stene Aviation and added skylights, a baggage door, float kit, extended baggage, V-brace and modern brakes.
As the plane was reassembled, all of the control cables, pulleys and bearings, plus the fluid and electrical lines and the fasteners, were replaced with new. The seats were stripped of their antique steel spring suspensions and replaced with lightweight and more comfortable materials. A larger and more modern panel with completely new wiring, circuit protection and instrumentation was installed.
Part one of my story ended with about two years of additional work to be done to get her flying again. I'm happy to report that we were successful. This article describes the completion of the work and my first few flights in this aircraft.

Install, remove, repeat...
As the big parts of the plane received the cleaning-primer-and-paint routine, it began to get exciting... then the work to install, wire and test all the radios, avionics and plumbing began. This takes much longer than you would expect, so be patient with your shops.

I cannot tell you how many times this panel was installed and removed during this process—each time a part is added, you need to check fit and function and verify no interference with other parts of the plane.
Then we were able to insulate behind the panel, the cabin side of the firewall and install the new control cables to the panel.

Next we punched holes in the firewall for the fluid, electrical, tach, primer, pressure and control cables. (Yes, this is scary... you measure three times and hope to cut once!) Then it was time to route cables, checking again for interference and binding. The same process was repeated for primer, oil, fuel and manifold pressure lines.

About this time, we fired up the panel while in the plane and performed a pitot, static and function checkout of the radio, transponder, encoder, intercom and panel lights. It all worked perfectly!

Connections, replacements and updates
The avionics tech turned the plane back over to my command to complete the connections for heat controls, governor, carb heat, mixture and throttle.
We replaced all the fluid lines firewall forward with new, and the gascolator was replaced with a modern aluminum-style one.

The old wet cell battery was replaced with a gel cell battery and stainless battery box from F. Atlee Dodge. We installed power and ground cables from Bogert.
The engine-side EGT, CHT, fuel pressure, oil pressure and oil temp sensors that feed data to the Grand Rapids Technologies' engine/flight data collection system were installed, and we were careful to keep these completely separate from the direct-reading "steam" gauges required of the TCDS.

Moving the fuselage—
and a twisted elevator cable
Now it was time to move the plane from the avionics shop to my shop. We padded and wrapped the entire fuselage and loaded it onto a flatbed car hauler in order to drive the 50 miles to my home field. I found that I enjoyed the project even more once I was only four miles from home with heat, good lighting and all my tools at hand to complete the assembly.

The flaps and ailerons were sent out to be re-skinned while the paint shop finished adding the color coats to the cowl and other small parts. My goal was to hold off on mounting the wings as long as possible because it's much easier to move around the plane without them.
Since the plane is equipped with Federal AWB hydraulic wheel skis, we installed new hydraulic lines beneath the floor that terminated next to the brake line exit at the gear leg. The placement of the taps is critical in order to allow the rear seat to be installed without interfering with the hand pump that mounts just behind the fuel selector/flap tunnel.

Before closing up the rear part of the fuselage, we made one more check to adjust elevator, rudder and trim for proper tension, function and limits. We found the elevator cable run had a twist, and that required a trip to the rear of the plane to fix. Using a digital camera sure made it easy to spot the trouble and get it corrected.

New windows, seals and seatbelts
The window frames were cleaned, primed and painted next. New plexiglass was installed and the window hinges were riveted to the doors. Door and window seals that use modern soft rubber make the cabin draft-free and quiet. We got ours from Aircraft Door Seals.

We installed BAS inertia reel harnesses and test-fit all the seats in the plane. This was the first time I was able to sit on the actual seats inside the cabin with the panel fired up and see it all come to life...what a great feeling!
The cowling, flaps and ailerons had come back from the paint shop, so we finished testing and securing sensor wires around the engine, and double-checked and marked with Torque Seal all connections in the engine compartment.

Then we mounted the lower cowl. It fit, and all the colors aligned! Same with the top cowl and doors! So we took it all off and riveted the inspection door hinges. We also added Teflon tape to prevent chafing of the paint where the inspection doors contact the fuselage.

Attaching the wings, control cables, flaps and lights
With five or six good, talented and patient friends, we moved the wings into place. We proceeded to test-fit, adjust and repeat until each wing fit securely into place. The spar attachments lined up nicely; no contact with the new one-piece plexiglass windshield from Great Lakes Aero Products.

We set the rear washout adjust blocks into the center position to begin with, and it turned out that was perfect—no further adjustment was needed upon test flight.
New stainless steel control cables were installed, along with new pulleys. (One gets very patient at feeding washers and nuts into blind areas with a magnet and dental pick during this phase of the project!)

There is a good reason that aluminum rather than steel retainer pins (i.e., cotter keys) are used with the cable/pulley systems: they are often placed in areas where it would not be possible to remove them unless they are soft enough to be grabbed and pulled out with long, thin picks. Their function is simply to retain the cable (in the event of it becoming slack) within the operational groove of the pulley.

As I mentioned earlier, checking cable runs to look for overlaps and/or rubbing can be made easier through the use of a small digital camera. Back in the old days, we had to do the best we could using lights and mirrors—but nowadays you can just stick a digital camera (or cell phone) in the hole, point it in the general direction you want to inspect, take your photo, and examine the image by zooming in where needed.

We used an eight-foot-long section of 1/8-inch aluminum tubing to guide many of the cables through the wing ribs.
The aileron bell cranks, cables and pulleys were installed. The ailerons were mounted and everything was adjusted until they operated in both directions evenly and to specified up and down angles.

The flap operation bell cranks, cables and pulleys were installed and set to initial factory settings. Since this aircraft was introduced in the mid-1950s, the flaps have seen improvements in design that prevent the track/guide wear issue common on these Cessnas. We installed the latest flap roller upgrade kit by McFarlane, and installed the flaps and made adjustments. Then we installed trim fairings around the wings.

Next we moved to the left wing and installed the landing/taxi lights, pitot, stall warning and all associated wiring into the cabin. It took a lot of time and patience to adjust the interior wing root fairings that have the air vents in them because of the change in wing shape with the leading edge cuff installed.

Fuel and vent lines, fuel system checks
We connected the fuel and vent lines, added some fuel to each tank to check for debris, flow and leaks... yup, we had to redo the top gasket of the fuel selector valve. The fuel flow sensor requires calibration, so it provided an opportunity to run a lot of fuel through the system. We also installed new fuel tank caps.

The mechanical fuel level tank gauges were not functioning, so the tanks were drained and new floats and gaskets installed. Be very mindful of proper ventilation, residual fuel vapors and sparks from tools whenever you're working around fuel tanks.

Necessary approvals, STCs and other paperwork
The request for a Field Approval on the three-blade MT composite prop was approved, so we mounted the new prop and made the final fit of the flywheel and alternator belt. By the time you read this, my company, Flight-Resource, LLC, expects to have its STC amended to install this three-blade prop to 360-powered C170, 172 and 175 aircraft.

We rented digital calibrated scales and determined new empty weight for the 170B was 1,405 pounds—only 70 pounds more than the last weight and balance report done some 30 years ago.

We also collected and reviewed the rest of the paperwork. In all, the changes, new parts, and replacements required over two dozen 337 forms to document the installations. My A&P/IA and I did a very thorough inspection, and he approved the plane to return to service.

Test flight and temperature checks
It was just one week before EAA AirVenture 2014 and I wanted to be there to park with the C170 group. The plane was filled with fuel, and following a careful preflight check (with notes of key measurements to be monitored), the engine was started for the first time.
It ran great!

The prop was cycled several times to purge air and verify operation while the plane taxied to the end of the runway. Oil temp and CHT were good for takeoff.

With full power applied, she was off the ground faster than I expected. I continued to run at high power in a shallow climb, circling the field, to about 3,000 feet AGL. Then I began to check and record temps. Oil pressure and oil temperature came down and became stable after about 50 minutes.

I slowly reduced power and landed—and we all celebrated with a beer and high-fives.

The engine went through about three quarts of oil before consumption stabilized. I've found that there is zero oil consumption when the engine is filled to seven quarts on the stick. If it's filled to eight, it will drop to seven in a short time and stay there—so I will keep it at seven quarts.

I run a semi-synthetic oil with CamGuard added. (For more information about CamGuard, take a look at "Engine Preservation" by Steve Ells on pages 36-41 in this issue. —Ed.)

The first oil and filter sample came back from the lab "normal" in all tests for a new break-in engine.
Last summer, I flew the plane to Oshkosh and parked with the C170 type club. Great fun! On the way back, I made a precautionary landing in a field when my fuel pressure began to drop into the red.

It turned out that a collection of spider webs and bug debris had clogged the filter in the gascolator. Easy to fix in the field and move on. When I got home, we flushed the tanks and lines and cleaned all the filters; I've had no issues since then.

First impressions
I have about 70 hours of flight time on her now. In September 2014, I took a five-day trip covering nearly 2,700 miles from Wisconsin to Wyoming and Montana, and back. The trip allowed me to spend a lot of time exploring various power and rpm configurations to determine the fuel flows and speeds that my Better-Than-New 170B is happiest with.

The gauge I love the most in this aircraft is the flight data computer—the fuel flow/remaining fuel functions in particular. It's so comforting to know exactly how much fuel you have at any time and be able to know precisely how much will remain when you land at a given waypoint or destination. Using this system, I was able to determine "best range" settings for power, prop and mixture.

Because this is a carbureted engine, it runs rough at lean of peak settings, so I operate in cruise at 50 degrees rich of peak. It seems at nearly all power settings, rpm, OAT and altitudes—temperature on the hottest cylinder (number three) turns out to be about 1,400 once leaned out and settled in.

MT propellers love to operate at low rpms. I cannot describe in words how pleasant it is to cruise around at 1,900 rpm and 22 inches manifold absolute pressure (MAP)—it's so quiet and smooth!
For my trip out west, I found happiness at 2,000 rpm, 23 inches MAP, density altitude 6,000 feet, fuel burn at 7.8 gph and TAS at 116 mph. Bump it up to 24 inches and 2,300 rpm and I'll get 126 mph TAS at 8.7 gph.

The takeoff and landing ability of this plane is nothing short of spectacular. I operate from a grass strip at 1,000 feet MSL, and it's easy to get the wheels off the ground in as little as 200 feet using those big flaps to jump it in the air, then easing them back off with the nose down until climbing speed is made to clear any obstacles.

The 170B flies very slow; with full flaps and power, you can get it to stall just under 40 mph IAS. Stalls are rather a mush than a break. When flown at max gross weight, there is very little change in performance compared to flying with the O-300 in front.

The interior trim has been
completed—we went with simple and
lightweight. I would not have installed the front-side kick panels except
they have the integrated heat ducts needed to move some heat to the rear
of the plane.

A local upholsterer made a blanket to keep in engine preheat, and the control wheels and grab handles are finally covered in black leather.

We've also completed the installation of the hand pump and the wheel skis. The system works wonderfully—you can use the skis or wheels interchangeably. Though I didn't get a chance last winter, this will be a great plane to take ice fishing on remote lakes.

I plan to keep the plane in this configuration and bring it to Oshkosh again this summer. Many visitors there never get a chance to see a ski plane up close...

Better than new at any price
Yes, I have invested an enormous amount of money into this plane to make it new. My justification is simple: a new Husky, Scout or Maule can claim more than $200,000 of your money; a new Cessna 172 is north of that.

I wanted a four-place, aluminum plane with conventional gear, digital panel, hydraulic wheel skis and a useful load of nearly 1,000 pounds that can fly all day long on eight gph in and out of short, unimproved strips with visibility nearly unmatched.
Come to think of it... there's no such plane produced today at any price!

John Nielsen is a 2,500-hour private pilot with 2,300 of those hours in tailwheel aircraft. He is one of the owners of Flight Resource (, which holds STCs to install the high performance MT composite propeller to hundreds of models of aircraft from Piper Cubs to jet prop commuter airlines. Send questions or comments to .

Aircraft Door Seals, LLC

Aircraft Spruce & Specialty Co.

B.A.S., Inc.

The Bogert Group

F.Atlee Dodge Aircraft Services, LLC

Flight Resource, LLC

Grand Rapids Technologies, Inc.

Great Lakes Aero Products, Inc.

McFarlane Aviation, Inc.

Mtn View Aviation
(The Door Steward)


Stene Aviation