Deserving of Respect and Praise: Cessna's 421C

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Deserving of Respect and Praise: Cessna's 421C Photo: DanSar Aviation

December 2015

Throughout this year I have written articles for Cessna Flyer, and members who are familiar with my writing know that I do not focus on the “how high, how fast and how far” data; that information is easily obtained from many internet sources. Instead, I try to answer questions.

I’ve shared my knowledge and experiences with the Cessna 340A, 414/414A Chancellor and the 425 Conquest I. (Refer to “‘Big Airplane’ Safety: A Cessna 340/340A buyer’s guide” in our March 2015 issue; “Bigger, Faster, Better: The Cessna 425 Conquest I” in June; and “Less Gets More: The Cessna 414A Chancellor” in August. —Ed.)

I am now pleased to present information on the Cessna 421C Golden Eagle. I’ll focus on the standard 421C manufactured from 1976 to 1985, and where appropriate, I will mention the 1967–1975 421A/B and the 421C with RAM engine conversions.

Not a single 421C was made in 1983, and only a few were produced in 1984 and 1985. Yet altogether, 863 of the 421C models were built. This number has been reduced to approximately 500 by original and subsequent exporting, insurance-totaled aircraft and other actions.


Comparing a 421C with other Cessnas
I am often asked to compare the tiptank 421B or 414A Chancellor with the 421C.

The 421B tiptank twin Cessna has fuel carried in the mains (tips), auxiliary fuel cells in the wings and optional nacelle tanks. Fuel capacity varies. The landing gear is the standard electromechanical system that is on all tiptank twin Cessnas.

Though I challenge the belief that the 421B model’s fuel system is complicated (and an operational and maintenance problem), I will acknowledge that the 421C model’s wet wing fuel system can be considered an improvement.

The wet wing design of the 421C allowed for the landing gear system to be hydraulic with fast gear operating and extended speeds, plus a simpler emergency extension system.

The simplest way to compare a 414A with a 421C is through useful load/payload. Chancellors typically have a useful load (fuel/people/baggage) of 1,750 to 1,950 pounds.

The 414A’s main tanks (the wings are the fuel cans) hold 202 gallons of useful fuel or 1,212 pounds. Therefore, with a typical useful load of 1,850 pounds, you would have a payload (people and baggage) of 638 pounds. Not great—but many flights do not require 202 gallons of fuel.

By comparison, the 421C model will often have a useful load of 2,000 to 2,300 pounds. With only the main tanks (wings) filled (206 gallons/1,236 pounds), there will often be a payload of 1,000 to 1,200 pounds.


Fuel system
The 421C’s fuel system could not be easier to understand and operate. Each engine gets it fuel from the main tank (wing) on the respective same side.

There is a crossfeed capability which allows an engine to obtain fuel from the opposite main tank (wing), as well as an off position. The fuel selectors positioned on the floor between the cockpit seats are placarded with the straightforward “Main,” “Crossfeed” and “Off.”

To provide the range and endurance that many buyers desired, Cessna offered optional nacelle tanks. One or two 28-gallon nacelle tanks could be ordered from the factory. These rubber cells are positioned in a cavity just aft of the engine firewall.

On the majority of 421Cs, a single left-side nacelle tank is installed to allow for a storage area that accommodates 40 pounds.

Often you’ll hear this 28-gallon nacelle tank referred to as a “wing locker tank,” but the term “nacelle tank” is more accurate, because 18.5-gallon aftermarket tanks are also available for installation in the 40-pound storage area. To distinguish between the types, the smaller aftermarket tanks should be referred to as “wing locker tanks” and the factory-installed 28-gallon tanks as “nacelle tanks.”


From 1976 through 1985, one important choice was required of the person specifying a 421C: order an aircraft with factory-installed air (as most were), and only the single 28-gallon left side nacelle tank was possible.

The Cessna factory air conditioner is positioned in the cavity where a 28-gallon right side nacelle tank would be installed. This option created a total usable fuel capacity of 234 gallons (206 gallons in the mains and one 28-gallon nacelle tank).

Some aircraft were spec’d with both nacelle tanks; this meant no factory air-conditioning was possible. Aircraft that were ordered with two nacelle tanks and no air-conditioning might have been going to Cessna dealers, or perhaps a buyer in the northern United States or a northern European location.

Aircraft with two nacelle tanks are referred as having “double nacelle tanks” or “dual wing locker tanks.” These units have a total usable fuel capacity of 262 gallons (206 gallons in the mains and two 28-gallon nacelle tanks).

However, many 421Cs may have the 262-gallon, two-nacelle-tank system—and still have air-conditioning. These aircraft are equipped with the popular JB/Keith Electric Air-Conditioner. (Air Comm Corp. now owns Keith Environmental systems. —Ed.) The air-conditioning components are in the lower left side of the nose base, opposite the heater which is in the lower right side of the nose.


Landing gear
When the 421C was introduced in 1976, the new wet wing fuel system allowed the landing gear system to be converted to a hydraulic system.

This redesign eliminated the inner gear door—a door that had to open and close with the retraction and extension of the gear—and the landing speed considerations that went along with it.

Cessna 421s with an inner gear door require the aircraft to slow down to 140 kias before extending the gear, because indicated airspeeds over 140 kias can damage the inner gear door. If the door gets bent/twisted, the gear may not properly retract or extend.

With the inner gear door eliminated on a 421C, the gear can be extended (VLO) at 176 kias, which is also flaps-15 degrees speed; and be flown at 176 kias (VLE). It’s a significant tool which allows for high-speed descents.

Another feature of the hydraulic system is the fast operating time. With both engines operating, the gear will retract in 4.5 seconds. In the event of a single-engine emergency, a fast cleanup is critical.

An additional plus of this hydraulic system is the 2,000-pound nitrogen bottle which blows the gear down in the event the gear will not extend. Blowing the gear down on final beats cranking the gear down any day.

Even with all of the benefits of the hydraulic gear, beginning in 1980 the gear design for the 421C was changed to a trailing-link style system. The 1980 trailing link units have a basic premium of $80,000 over a 1979 unit.

The 421Cs with the trailing link gear tend to sit more level, and the first step up is greater.

The 1976–1979 421Cs with non-trailing link gear (but still a hydraulic system) tend to sit a little tail-low. This creates a smaller step up for the first step on the airstair door, which can be a plus for Part 135 air taxi operations or anyone having older passengers.

An often-unknown fact is that 421Cs with the trailing link gear cannot have RAM winglets.


Airframe modifications
There are five popular airframe modifications for Cessna 421C aircraft.

Vortex generators (VGs) are little “con artists” that fool the aileron and rudder into acting as if they were going faster. This creates additional aileron authority (roll control) and additional rudder authority (yaw control). In the event of a single-engine emergency, VGs can allow the pilot to have more control in combating the aircraft’s tendency to roll and yaw.

In addition, VGs aid in reducing takeoff and landing distances. They are not a STOL system, but having the ability to safely take off and approach at slower speeds results in reduced takeoff and landing distances, and saves on brakes and tire wear. Several companies offer VGs for twin Cessnas; cost is typically around $3,000.

Winglets may be installed on the 421C’s straight wet wing and this mod aids rate of climb and offers some speed benefits, too. A 421C with winglets is referred to as a 421CW. Most 421CWs were modified in the 1990s/early 2000s. Winglets are expensive to install and few owners or purchasers add them today.

Aft fuselage strakes are one reason why fewer aircraft are getting winglets in 2015. The aft fuselage strakes (fins) that go under the tail are an excellent modification for the price. For approximately $15,000 installed and painted, the aircraft will gain six to nine knots in cruise and have improved yaw control and a better ride in turbulence.

Another mod is the addition of hub caps which aid in cleanup of the airflow around the retracted gear. Depending on the style, a pair of covers can run between $1,500 and $2,000.

Finally, spoilers (speed brakes) are a valuable plus for any twin Cessna. Spoilers can be used to control speed and descent without a huge power reduction, and they have no speed restrictions as do the flaps and landing gear. Spoilers are hydraulically activated and cost approximately $15,000 installed.


Factory kit for FIKI-certified 421Cs
It is rare to find a 421C that is not FIKI certified. This optional factory kit consists of outer and inner wing boots, plus the horizontal and vertical stabilizers are booted.

For 421Cs with winglets, the extra leading edge wing area may be booted by using the boots for a 414A Chancellor. (This action is not required for it to remain a Known Ice aircraft, though.)

In addition, each propeller blade has a heated anti-icing boot which prevents ice accumulation on the propellers. The fuselage has an ice protection plate which takes the hits from ice thrown by the propeller, thus protecting the aircraft’s skin.

The pilot’s windshield is heated, too. Early 421Cs had a heated plastic windshield while later models have a heated glass windshield. Aircraft with plastic pilot’s windshields get a deduction during an evaluation.

A 421C FIKI aircraft will have dual 100 amp alternators, and the pitot tubes, static ports, stall vanes and fuel vents are heated. An ice detection light shines on the wing boots.


The 421C is powered by Continental GTSIO-520-L or -N engines. The -L version is on 1976 through 1980 models, and the -N is installed on 1981 and newer aircraft. Both engines provide 375 hp and have a 1,600-hour TBO.

I stress to you that regardless of whether the engines are factory-new or rebuilt engines, RAM-overhauled engines or field-overhauled, the horsepower is always 375. No mod or conversion changes the horsepower or TBO on a 421C’s engines.

Owners and prospective buyers should understand, though, that in FAA Part 91 operations, TBO is only a suggestion. (The same is true of propeller TBOs.) The goal of every 421C operation should be achieving TBO and beyond.

If at an annual inspection a cylinder or two has a low compression reading, adding a serviceable cylinder or two can be wise. Often there is no need to overhaul or exchange an engine or replace all cylinders. I recommend that the owner/operator have an attitude of stretch and stretch.


The propellers on 421Cs are wide-chord 90-inch diameter three-blade heated McCauley or Hartzell propellers. Various models, depending on RAM engine conversion and STCs, may be on the aircraft.

Most pilots’ and passengers’ ears are accustomed to propellers that spin at 2,400 to 2,500 rpm. The large propellers on the 421C turn at only 1,800 to 1,900 rpm. These large, slow-turning props provide the required thrust along with a very quiet cabin and cockpit.

A few 421Cs may be equipped with the four-blade MT composite propellers. Four-blade propellers will add quietness, but are expensive.


Most 421Cs are set up with seven seats: two cockpit; four cabin/club; and the seventh seat is the potty. Though legal, I know of no one that uses the potty seat. It is small and faces inboard.

Some cabins have an eighth seat, but the majority of the time this seat is stored in a hangar. When installed, it takes up valuable baggage space.

Two executive tables, the aft cabin potty and an aft refreshment center are typical cabin features in 421Cs. A few aircraft will have a forward refreshment center positioned behind the pilot’s seat.


Paint and interior
It is fair to say that a quality paint job will cost $25,000 to $35,000 and take six to eight weeks or more to complete.

Delays usually have one of two causes. Often, the shop just took on too much work—and it’s difficult to lose business by stating up front it will be three months before they can start and three to four months in the shop. Other times, the excuse will be (and it’s sometimes true) that problems such as hail damage were discovered and had to be repaired.

Interior redos offer a wide range of selections and options. Costs can range from $20,000 to $35,000 for a quality full-interior project.

If you are planning a new interior, my advice is to have a detailed contract addressing materials, woodwork, electronics and all personalized actions spelled out. Damaged or missing items must be listed; photograph the problem areas. In addition, note any “change” procedures, which can affect cost and schedule.

Many paint shops will farm out interior work. The aircraft’s interior components often go to an off-site interior shop and therefore, the paint shop’s control of the interior work is minimal. Thorough research, questioning and inspections are well worth an aircraft owner’s time and investment.

Finally, remove all aircraft logbooks/records, POH and equipment manuals along with the airworthiness certificate and registration. No paint or upholstery shop needs these items to do their work. Unfortunately, the loss of documents and equipment is common and can lead to heartache—plus, none of these items can be held hostage if there is a dispute.


Maintenance is the subject of many articles, and my advice on this is simple. Your local A&P may be a nice guy who is working hard to make a living. His rates are low. It is easy to get scheduled in and the completion is quick. He is on the field or nearby.

I’d caution you to consider that convenience can be costly. Confirm with your mechanic how many twin Cessnas and 421Cs are worked on regularly. How many annual inspections on these models are completed annually?

To keep a 35- to 40-year-old 421B/C in excellent condition requires certain maintenance be performed by an experienced specialist—much like the medical specialist that you’d insist sees your child, or the legal specialist you’d hire for a serious legal matter.

I regularly see the costly results of convenience. Well-meaning and hardworking local mechanics who only see a couple of local twin Cessnas and perhaps only one 421C a year simply do not have the day-to-day experience to keep this great airplane in superb condition.


First, the Roman numeral (a II or III) seen in twin Cessna ads, on specification lists, and/or on an aircraft exterior is often misunderstood. Do not get these confused with the Roman numerals used to identify a RAM engine conversion (such as RAM IV, VI or VII).

The II or III package was simply an equipment package offered by Cessna on new twins.
Few (if any) aircraft today are a true 421C II or 421C III, as most of the avionics have been removed, changed and/or modernized. It is truly rare I see an aircraft that in 2015 has not had any avionics and/or equipment changes from its manufacture, and if so, its value will be dramatically reduced.

In addition, the model year of a twin Cessna is not based on when the FAA issued an Airworthiness Certificate. The manufacturer established a block of serial numbers that are designated as being a model year.

For example, 1979 421Cs have a serial number range of 421C-0601 to 421C-0715. These units are 1979 421Cs. However, the late 1979s, such as serial number 421C-0702, might have been manufactured in October 1978.

As it goes out the door, Cessna was authorized to issue an Airworthiness Certificate on behalf of the FAA. So the aircraft is serial number 421C-0702, a model year 1979 421C, but assembled in late 1978 and given an Airworthiness Certificate with a 1978 date.

Pilots, owners, buyers and bankers will say it’s a 1978. Wrong! It is a 1979 Cessna 421C.

Just look in your local newspaper. I suspect your reading this article in December 2015. Automobile dealers now have vehicles in stock that are 2016 models. A 2016 Lexus, coming from Japan, was assembled in the summer of 2015.

Finally, the number-one statement I hear on the hundreds of calls I receive is, “Jerry, just one more question.” It’s okay, I am good with it.


What about costs?
Ready? A proper buyer’s pre-purchase inspection will cost $3,000 to $5,000.

If the aircraft is subsequently purchased, the pre-buy will often roll into an annual inspection. That is, the pre-buy inspection can count as the inspection phase of an annual, and the pre-buy cost is credited toward the annual.

A 421C buyer should budget $15,000 to $20,000 for a quality annual inspection. The flat rate from a twin Cessna specialist—which is just the inspection phase (no repairs)—will be $3,000 to $5,000.

When I hear that the cost of the last annual inspection was $4,500, I get a bad feeling. When aircraft go to a pre-buy performed by a skilled specialist—which is a buyer’s right to have—often the true costs of convenience are presented.


Proper training is as critical as a comprehensive pre-purchase inspection and quality ongoing maintenance. When I hear a customer say, “I have a friend who flies a King Air” or “I’ve got an airline buddy that use to fly twin Cessnas who will check me out,” I get concerned.

I’m concerned because poor procedures and techniques may be presented during this type of training which may compromise the aircraft’s capabilities. Worse yet is a buyer’s loyalty to a local flight instructor who is both excited and unqualified to teach the systems.

I encourage simulator training, but I am also a regular witness to new owners who have attended a simulator school course and are now instrument proficient, but really do not have a grasp of systems.

The nature of the sim school syllabus and training schedule does not allow for a three-hour cross-country where fuel management and descent management can be demonstrated. My recommendation is to go to sim school and also fly with an instructor experienced in the aircraft type.


Owners’ associations
Membership in three or four owner’s groups is beneficial. The monthly or bimonthly magazines each offers are worth the dues/subscription fees. If you can afford the aircraft, you can afford a few hundred dollars annually for ownership support.

Attendance at owners’ group seminars is also smart. Hear the latest real-world twin Cessna news, speak with other pilots and develop a network of your own resources for support.


A GA benchmark
It is a mouthful: Piston-Powered, Pressurized, Cabin-Class Twin. But the 421C deserves all the respect and praise that is possible.

Regardless if the aircraft will be a firm’s first aircraft and flown by a pro pilot, or the common step up from a smaller twin or high performance single flown by an owner/pilot, the 421C Golden Eagle is a General Aviation benchmark.

Aircraft are best judged by how well they strike a balance, not by one single exceptional feature. The 421C offers good speed, a spacious and quiet cockpit and cabin, lots of external baggage space, excellent manufacturer support, numerous qualified maintenance facilities, quality training firms and a proven record of four decades.

It’s earned its name: Golden Eagle.

On countless post-sale delivery flights, while cruising at a flight level with a quiet 8,000-foot cabin, seeing the avionics and equipment doing their thing, I have asked a new owner, “Are you pleased?”

Every time, I’ve seen a smile. And often I hear a one-word reply.


 Jerry Temple founded Jerry Temple Aviation (JTA) in 1995. JTA provides pilots with hands-on service from the research stage to delivery and checkout. Before founding JTA, Temple worked for 20 years in several positions in the Cessna Aircraft system, including at the Cessna factory as well as in distributor and retail sales. Send questions or comments to .

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