Rohn Ck Pt Iditarod
Cessna 185-B Skywagon
Tri-Star Aviation an FAR 135 1992 to 2014
N2550Z is no longer with us. Great memories rebuilding and
flying around the US and Alaska
This page chronicles the restoration of an Alaskan
N2550Z Trade-a-Plane cover
photo Dec 2007
I'm a flying
project Paint me!
Wings off, time to go to work.
Going together, notice new windows
A work in progress Radios are installed
padded dash not in yet
Interior primed DuPont DP50
Wings and control surface
Painting screws and washers
Finish N-Number shadow blocked
Belly Pod installed
EDO 2960 floats
Cessna Aircraft first built
the 180 series in 1953's. In 1960 the Cessna-185 was born. It was almost
identical to the C-180 except for adding fuel injection to the continental
O-470 increasing the horsepower from 230 to 260. Through the years Cessna
added a many improvements to the C-185, most notably the addition of the
Continental IO-520 at 300hp. Production was ceased in 1980 with
thousands of C-185's being built.
First I must
preface, undertaking a project of this magnitude requires some resources. A
little extra cash and the necessary knowledge, skills and the FAA Airframe &
Power Plant (A&P) license. While not having an A&P license would not be a
limiting factor in restoring an aircraft, there are many skilled mechanics
who are not A&P certified. Anyone without an A&P license would need the
supervision of a licensed aircraft mechanic to ensure compliance with FAA
maintenance practices, (FAA Advisor Circular 43.13) and applicable FAA
regulations. Proper inspections and signoff of work preformed. Aircraft log
book record keeping is required ensure a restored aircraft maintains it's
airworthiness certificate and is of course safe to fly.
You also need
a working knowledge of the processes and chemicals you'll be working with,
most are highly flammable, toxic and even carcinogenic. You must take
extreme caution and use proper protection.
I've have my
A&P since 1978. Having owned, maintained and rebuilt 6 aircraft in the last
25 years I was confidently looking forward our newly acquired project, a
Diana and I
purchased this 185 with the intension of not only restoring but upgrading it
with many of the STC modifications developed over the last 40 years. Many
STC are designed to increase the utility and safety of these old workhorses.
This 185 has a factory float kit, has been operated on floats and wheel
skis. It also has a cal Center Leading edge cuff. We also had a time line
set. After the restoration we planned to fly it to Oshkosh for Airventure
2005! The race was on.
1. Restoration outline: This Cessna 185, at over 40 years
old has only 3700 hours. Not bad at all for it's age. However
with the original paint, 50% pealed off, leaking fuel bladders
and crazed windows it's in need of a lot of work. The big
question was corrosion. With most of the paint weathered off and
a life in mostly a dry environment there was very little and the
repainting prep would take care of it.
When the restoration is complete we want a late Cessna 185 paint
scheme. Bright colors for collision avoidance and top wing
surface painted other than white. Here in Alaska dark wings
absorb the sun even on sub-zero mornings, clearing frost.
Modifications: How deep are your pockets? You can spend
thousands tricking out a Cessna-185. We opted for the most
utility. All windows and windshield replaced. Heavy duty one
peace Cee Baileys, no more center strip on the windshield. Flush
patch several holes in belly from old antennas. New fuel
bladders. MLJ extended baggage. Floor level baggage extends 32"
aft. It's so low you have to install fairleads and lower the
control cables. In addition it requires moving the battery so we
also opted for the MLJ firewall battery. Installation uses the
Odyssey battery at 1/2 the weight of the old lead acid, immune
to cold, mounted on the firewall, with all the old wiring
removed. Two Cessna Skylights over the main fdw cabin added,
collision avoidance, great watching for traffic in a turn.
P-Ponk gear mod from Steve Knop. This Gear box mod is for skis.
Alaska SkyCraft cargo/fuel belly pod, an extra 29gal and 7cuft
of storage space. Continental IO-520-D engine, about the most
important upgrade. Operating on skis and floats in Alaska you
need the 300 horsepower the IO-520 provides. The engine upgrade
will include the McCauley Black Mac 3 blade prop. Considering
fuel prices these days I'll install GAMI Injectors and save 1 to
2 GPH. Electronics International UBG-16 engine analyzer with 6
point EGT/CHT. FP-5 fuel flow/used system. Tanis preheat system.
Interav Alternator conversion. AWI heavy exhaust system with
large muffler for extra heat and extended stack. The AWI exhaust
system is a welded heavy gauge stack with only one sleeved
section thus getting rid of all the leaking clamps the old
exhaust uses. Replaced all engine controls for smooth engine
It's never Finished
I planned the restoration in 5 phases.
1. Outline; What will it look like
and what modifications
do we want.
3. Stripping and Cleaning.
4. Repair and modifications.
5. Prep and Paint.
7. IO-520 upgrade.
8. EDO 2960 Floats, recondition.
Interior: Removed the all the old original junk and add;
ICom Intercom with CD played plug, ICom digital transceiver, KX170B with ILS, KX-76A
encoding transponder and Gramin 296 GPS. Install
sound/foam in cabin, new supple headliner, fiberglass side
panels, recovered seats in leather and padded dash with LED lighting.
Always first, remove the battery, don't need any hot wires
I took extra care in removing wings and all controls surfaces. Tagging cables and
wiring. Catalog any damage needing later repair, listing and measuring all AN
hardware. I find a lot easier when ordering new hardware for final assembly.
Built wing and fuselage stands. Remove fuel bladders, all windows, windshield,
battery, old wiring, interior and avionics with excess wiring.
and Cleaning: About the toughest part of the whole restoration process.
Working with chemical aircraft stripper is very hazardous and requires a lot of
preparation and care. Invariably when working with stripper you get It on your
skin, it's best naturalized with water. In the time it takes to pick up a wet
rag and wipe off a drop of stripper from your skin the top layer of skin comes
off, you have a light chemical burn with fresh skin exposed, it's painful.
Imagine if you got a splatter in the eye! It
took 20 gallons of stripper for this project! I only strip outdoors, the fumes are very
strong and toxic. You just can't get enough ventilation to use this stuff indoors.
My proved method
is to lay down poly sheeting. After stripping it's rolled up and disposed of,
removing all expended stripper and stripped paint. Stripper is best used on cool
60'f overcast days, less likely to dry out and become ineffective. Gear-up,
elbow length acid gloves, rubber apron and goggles. Apply liberally let stand
for 10 to 20 minutes, work into old paint with stiff brush or Scotch-Brite. As
stripper becomes less effective scrape off with plastic scraper and re-apply. The
old paint comes off in millimeters and by layers, it's a long process. Stripping
everything took 3 days. After stripping each major piece I roll up and
dispose of drop sheeting.
with hot water, high pressure washer. I use a Kracher gas powered 4500psi unit.
Pressure wash scrub and pressure wash. Every bit of old stripper residue must
be removed. Any stripper left, especially in seems will cause future corrosion
under the new paint.
4. Repair and
Modification: As any mechanic knows, this is when the fun starts. Having the
aircraft stripped cleaned and ready, the money spent and parts in hand, here we
go. Guided by the manufacture installation instructions and FAA AC43.13
bladders and completed some minor repairs on the wing tip fiberglass and set
aside till painting. Riveted fabricated flush patches in several old antenna
holes. Installed Transponder and GPS antenna. Fabricated template for Skylight,
riveted Cessna formers and installed two tinted widows overhead. Mount, install
and wire new avionics and engine instruments systems. Install clear side windows
and Cee Bailey windshield.
and Cory Houston installed the MLJ extended baggage, control cable fairleads in
belly and vinyl rear cover, P-Ponk blocks in Landing Gear, Atlee Dodge Fuel
Caps, BAS Shoulder Harness, BAS Tail Pull Handle, Alaska Bush Wheels, True Lock
Axel Retention System and firewall mounted battery mount,
solenoid and wiring
The Belly Pod
installation and IO-520 engine and prop upgrade will be accomplished after
painting. Belly Pod delivery delayed and can't afford the engine and prop till
next year. O-well can't have it all right away!
5. Prep and
Paint: Next to cleaning, painting prep is about the most important step. If
it's not done right the paint won't last and the restoration will look like crap
in a year. I use all DuPont products, Alumi-Prep, Alodine and DP50 primer. DP50
is a super etching primer great adhesion and easy to use.
Best taken in
stages, fuselage, wings then controls surfaces. Once again you gear up to
protect from chemical exposure. Alumi-Prep is applied then scrubbed with medium
Scotch-Brite to remove oxidized aluminum, dirt and oils. Clean with lots of
water to remove all cleaner. Alodine is then scrubbed on with Scotch-Brite. This
helps to inhibit corrosion propagation under paint. Rinse again with water. From
now till final painting I'm careful to handle parts only when wearing clean gloves.
Any oils from your hands will contaminate surface. I let dry overnight, tack-cloth then prime
I'm careful to
cover and keep cleaned primed wings, fuselage, controls, ect.
Paint: I used
DuPont Imron paint, it's extremely durable. 4775 White, 7455 Burnt Orange and
7502 Brown. We liked the combination of colors and the Orange we felt not only
looked good but was bright enough to help with visibility and collision
My weapon of
choice for shooting Imron is an HVLP. They deliver paint with warm high volume
air and produce very little overspray. It's a very easy system to master. Imron
is also a very toxic paint and my environment of choice is a full hood fresh air
respirator system. This brings fresh air from outside and is a must for any
painting. I hang a curtin of poly-sheeting around my painting area to keep all
overspray out of my shop area, using an exhaust fan at one end and a plywood
panel in the door opening at the other end with filters installed to reduce dust.
In stages, wings
first. I set up parts to be painted, mix paint, tack-cloth wipe, gear up in
tyvek suite, turn everything on and paint! I like to work the trap corners and
hard angles till covered.
Then I shoot a thin transparent coat in one direction,
a second thin coat in the other direction and after about 10 minutes a final
You can see when the paint fills, the texture is uniform and there is
a finish sheen. It's a find line and takes a practiced eye, if you cross it
you'll get sags and runs. Sags are bad, a whole layer of paint slides and I
don't have a good fix.
Runs can be fixed. I use a strip of masking tape, be
quick. While the paint is flowing apply tape and remove run, re-shoot a light
coat and hopefully you will have a seamless repair. I shot everything that was
being painted white first, including a cardboard box covered with all the
exterior screws and washers I would need.
The wings 1st coat
Three color finished wing
Laying out the
color pattern with fine-line tape took a full day. We took a lot of time to get
it looking uniform and straight. After masking all areas not taking color from
getting overspray I shoot another coat of white on the areas taking color. This
is a really easy and fool proof way to seal the fine-line tape and it totally
prevents the other colors from bleeding in to the white. Shooting the color is
as easy as it gets. I pull the fine-line tape while the last coat is setting up.
You have to be really careful, it's easy to screw up the wet paint but if your
successful the line edges soften and I think it produces a better finished edge.
After 3 days, 2
1/2 gallons of primer 3 1/2 white, 2 orange and 2 quarts of brown it was
finished, my best paint project yet. No sag, two small runs and only two edge
bleeds and I "didn't" kick the paint pot over once.
easy. We went with Mylar peal and stick, white with brown shadow block, a great
finish from Wes at Warning light of Alaska
One week before we were to depart for Oshkosh we hung the wings and began the
final assembly. Horizontal and vertical stab and all control surfaces mounted.
Assembled with all new AN hardware. Cables adjusted, rigged, tensioned and all fairings
installed. There are a lot of little thinks and attention to detail is
important, a missed wire or bad connection and something won't work right. This
is where tagging everything during dissemblely pays off. Fuel and electrical connected, no leaks upon fueling,
Upholstery from Merrill Field Airport installed the headliner. With the
skylights there were some tricky angles. Interior panels were an easy fit and
few odd and ends and interior complete.
fueled and successfully test flew on a Tuesday, no problems at all. Thursday
Diana and I loaded up our camping gear and headed across Canada and the Midwest
for Oshkosh and Air Venture trek 2005.
Modifications (Alaska Sky Pod): The Belly Pod from Alaska SkyCrafters was
delayed for a few months but finely arrived. These pods are a jell-coat
fiberglass construction and form fitted to the contour of the Cessna 180/185
belly. Installation was very straight forward. The pod is mounted to the
aircraft belly using AN-Rivnuts and structural machine screws. It takes some
time centering the pod on the belly and marking the access holes for the fuel
and electric and making sure mounting hole location do not interfere with
aircraft ribs ect. After drilling all holes and ensuring a perfect fit, I
removed the Pod and painted Imron 4775 White, same used for and main aircraft
color. Thus it was mounted freshly painted and not dinged up from installation.
Hooking up the fuel couldn't have been easier. Some installations require
cutting the fuel supply line. The 185 however has a belly fuel drain with AN-T fitting,
this was simply replaced with a AN-Star fitting and the supplied line to the
SkyPod fuel tank was attached to this fitting. Fuel is transferred to the right
wing tank when it's capacity allows, with a DC pump. A 10amp CB was installed
and wired with an operating switch and pump On light on the dash. A gallon of
fuel in the pod and some adjustments and a check for leaks and the Fuel/Cargo
Pod was installed. This extra fuel has extended the endurance range to 8 hours
in some cases. It's long time without a Lav on board.
impressed with the quality of these pods, ease of installation and the utility
they add. Other then painting it's an easy 8 hours. Alaska
offers two options, all cargo or Cargo/Fuel, (29 gallons).
modification: It's great being on the home stretch of this restoration
project. During the year and a half Diana and I have been at this, the 185 has been
flyable all but 4 months and this is the last one. We choose the end of October,
there isn't much good flying till after the 1st of the year when lakes and
rivers are frozen solid and the days start getting longer.
180/185's all my aviation career and seeing the developments, epically the last
10 years, I knew the way we would go in upgrading our 185 from the IO-470 to the
Teledyne Continental Motors IO-520.
We choose the
Kenmore Air STC for mounting the Continental IO-520D and the P-Ponk STC for
hanging the McCauley 3 blade BlackMac prop and polished spinner. The engine will include
the Continental oil filter adapter, New AWI exhaust with seaplane muffler
extension, 6 point EGT/CHT engine analyzer, Quantity/flow fuel analyzer, Interav
Alternator conversion and Tanis preheat system.
There are many
options out there for engine vendors. I spent several months keeping an eye out
for IO-520 deals. It paid off, found a IO-520 from an aircraft mishap, ran out
of gas and engine was stopped on landing but it was short of the runway which
totaled the aircraft. Very low time engine with ECI cylinders.
On engine stand ready to go
First flight, new engine
Removed the old
IO-470 and prop. I'll sell these and recoup some of my cost. Removed throttle,
prop mixture and cowl flap cables and reinstalled new veneer controls. Firewall cleaned,
and silicone some minor holes. Set up wiring, new hoses and new AN hardware as
Atlee Dodge Aircraft repaired, reconditioned and powder coated the old engine mount for use with the
IO-520. With the engine on a flange stand, installed the engine mounted with new
Lord mounts and built the engine exterior; Baffling, ignition, new AWI exhaust, EGT&
CHT probes, Reiff preheat, Gami injectors, fuel flow and the new electronics. It takes time and planning to
install, route and clamp wires and lines so as not to chaff or interfere and to
comply with the installation requirements. Even then they'll be some changes
after we hang the engine.
It took hours to
remove the IO-470 but it took 2 days to install and rig the IO-520.
8. EDO 2960
Floats: This last phase began in May
2006. Diana and I had planned a month to recondition the EDO floats we picked up
last winter. However they were in such bad shape, taking more time then I
expected, we didn't finish till August. Too late for this summers float season.
EDO 2960 before
Ready to strip
Rigged and ready to float
Alaska Skycraft Fuel/Cargo pod
My approach was the same as with the airframe,
dissemble, strip, repair, reassemble and paint. With the EDO aluminum
compartments and structure held together with steel hardware living for years in
a marine environment, it was no easy task. Most bolts especially the main ones
were corroded so bad penetrating oil was not enough to fee them, requiring
drilling the bolt itself. Floats were then stripped and the compartments cleaned
and pressure washed, removing years of silicone and whatever else was used to
seal them. Repaired and replace old patches as needed. Sealing the cleaned
compartments I use Randolph fuel tank sealer. I hang each float at it's balance
point, pore in some sealer then use a reversed vacuum cleaner and rock the float
coating the seams while air pressure forces the sealer into any gaps. works
great. After the sealer dries I reapply the air pressure and use soapy water on
the outside to check for any leaks. Sealing again as necessary This system works
great for getting a good tight float. Re-assembling with new AN hardware I coat
all the bolts with fuel lube. Fuel Lube is a pain to work with, sticky and hard
to clean, only MEK removes it but it's impervious to fuel or water and it
doesn't dry. Really helps with preventing future corrosion. After alidone it's
prime with DP-50 and Imron white and a little trim paint, done.
This Cessna 185 has a factory float kit and had
previously been on EDO floats so all the interior blocks were in place. May 2007
we married aircraft to floats. Hoisting, removing main gear, tail wheel and
capping brake lines. Installing main gear float stubs and rear blocks then
bolting the floats in place, attaching and tightening cross brace wires and
rigging water rudder and retract cables. Floated May 28, 2007.
Dynon EFIS D10A: To say it's never done is
an understatement. With the older flight instruments I decided to upgrade to one
instruments has all. The Dynon EFIS D10A instrument has Pitot Attitude, Density
Altitude, Pitot Airspeed, True Airspeed, Mag Heading, Vertical Speed, Turn &
Bank, Slip indicator and OAT all in one unit and it fits in the standard 3 1/2
instrument hole. Installation is simple, I repositioned the Attitude indicator
to an empty hole in the instrument panel and installed the Dynon in it's place.
The Dynon has a Laser Ring Gyro and only requires 12 or 24VDC which I connected
to a 2amp CB. I split the Pitot and Static lines, installed plastic compression
T's and connected to the Dynon for Pitot-Static input. Additional accessories
installed in the left outer wing were the temperature sensor and Mag Heading
Sensor. Dynon uses Temperature in connection with Pitot-Static to resolve and
display Density Altitude and True Airspeed. The Mag Heading Sensor stabilizes
the heading indication to Magnetic.
The Dynon unit is not TSO or STC approved and requires a FAA Form 337 for field approval by the
FAA. The FAA also has engineering guidelines for the installation of EFIS units
(Electronic Flight Instrument Systems) The FAA requires all required Flight
Instruments not be removed from the aircraft and placard "VFR ONLY". I have
found the Dynon very accurate and a great tool. When you consider the errors
these older flight instruments develop and the cost for overhaul or new
instruments the Dynon is an economical option.
If your installing an EFIS system in your aircraft here are links to the
documents the FAA requires. EFIS
Flight Manual Supplement and FAA form 337 back
page language. Format is MS Word.
Regardless of an Oil Change, Annual Inspection
or Restoration the FAA requires a record of all work preformed and return to
STC's, FAA form 337's and
LogBook entries: Here is a comprehensive list of the STC and field
approvals I used.
Most of the
modifications were installed under FAA Supplemental Type Data Certificate,
commonly known as STC. These are issued from FAA engineering to the
manufacturing vendor after meeting stringent design, engineering and testing
requirements. Each STC has it's own set of instructions or procedures. Sometimes
various options are available to comply with these instructions. FAA Advisory
Circular 43.13 has additional guidelines and practices which must also be
consulted and complied with. Modifications not covered under an STC were installed under a
Field Approval by the FAA, a onetime installation verified and approved by a
Cee Baileys Windshield CEE Baileys STC SA5451NM
BAS shoulder harness SA2067NM
BAS Tail Pull Handel SA3813NM
P-Ponk Gear Mod, PPonk Aviation STC SA2918NM
McCauley 3 Blade Black Mac Propeller, P-Ponk
Aviation STC SA00413WI
Alaska SkyPod, Alaska SkyCrafters STC
FP-5, Electronics International STC SA00068SE
UBG-16, Electronics International STC SA0068SE
IO-520D conversion, Kenmore Air. STC SA525NW
GAMIjectors, General Aircraft Modification Inc.
Folding removable Jump Seats SA 02008 AK
AWI Exhaust, Aerospace Welding Inc. New Exhaust
InterAV Alternator Conversion, Interav STC
MLJ Extended Baggage, Field Approval FAA form 337
MLJ Firewall mounted battery, Field Approval FAA
Reiff Turbo Preheat Systems
Snyder Wheel Skis, Dick Snyder STC
AirStreak Tundra Tires, AirStreak STC
True Lock Axle Locks SA00780SE
Cabin Skylights, Cessna OEM installation FAA form
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