Flying the Fokker C.IV

A Phoenix rises from the ashes

Two things occur to me every time I approach the C.IV for a flight. One is the size of the aircraft; the other is what it represents. To me, it epitomizes aviation in the 1920s. It is a personal time machine capable of transporting me to the Golden Age of aviation.

After you've checked the fuel, oil and coolant levels, only a few other items need to be attended to during the preflight. The landing-- gear shock cords should be checked to ensure that they have not jumped over the steel discs that retain them; this would prevent the axle from floating from side to side. The axle is completely free-floating and is not attached to the airframe in any way other than the wrapped shock cords. Each side of the axle is suspended within a steel ring that is a part of the landing-gear legs and is wrapped with 50 feet of 5/8-inch shock cord. Surprisingly, this system works very well.

The cowl consists of two clamshells on the top with two sides and a lower cowl shell. All cowl panels are secured with brass piano hinges with rods that are removed from the hinge halves to separate the panels. This system makes for a very clean and attractive cowl but does not lend itself well to engine inspection, as reinserting the long hinge pin after removing the cowl for a closer inspection is a tedious, sometimes frustrating task.

The engine has dual ignition but accomplishes this in an unusual manner: it has four, six-cylinder magnetos, each of which fires one set of plugs in one six-cylinder bank. The fuel/air mixture is provided via four carburetors located fore and aft between the cylinder banks: each services three cylinders. On top of each bank of cylinders is a large, bronze housing in which the overhead cam rides. The rocker arms protrude from each side of the housing-- outboard for exhaust and inboard for intake. The camshaft and rockers are pressure lubricated, but the valve stems require external lubrication between flights. The exhaust valves are easy to reach, but the intakes require a bit of maneuvering to lubricate with the cowl in place. Fortunately, much of the engine can be visually inspected with the aid of a flashlight without removing the cowl.

There are no flying wires to be inspected between the wings because one of Tony Fokker's design hallmarks was cantilevered wings that required no external bracing wires. The propeller was custom-built to our specifications by Sensenich Propellers and should be carefully checked prior to each flight. The ground clearance in the level attitude is less than eight inches; therefore, the propeller is subject to damage from runway debris. The propeller is 10 feet in diameter and is too high to be thoroughly inspected in the horizontal position; for a close inspection, it must be rotated with the blade down.

It's no easy task to enter the cockpit; it's a bit like climbing a stepladder with awkward rungs. There are three steps, and your foot position must be switched on the last step unless you wish to fly the aircraft facing aft. The cockpit is very roomy, and when you sit in it, you get a good impression of the aircraft's size. A great deal of airplane is in front of you-about 12 feet. The nose does not angle down, which makes forward visibility on the ground impossible. The cockpit has a unique way of accommodating pilots of different sizes: the seat is fixed, but the rudder bar has hat-shaped extensions that flip down so shorter pilots can put their feet on it to actuate the rudder bar.

The starting procedure is straightforward. As the engine is primed-using the primer from a Stearman located in the cockpit-- the propeller is pulled through about 10 blades. About 10 strokes of the primer are usually sufficient. After the engine is pulled through and primed, a door in the right side of the cowl is opened and the starting crank is removed from its retaining clips on the firewall. It is then inserted into its socket and turned counterclockwise while the engagement lever is held until the crank engages. Once the crank is engaged, it is removed, the door is closed and the crank is reinserted through a hole in the door. At this time, the magneto switches are turned on, and when an individual turns the crank, the pilot engages the button for the battery booster, which delivers a hot spark. The engine usually fires within the first blade.

A few changes have been made to the ignition system from the original. Two of the four Watford C.6 magnetos have been replaced with modern Bendix magnetos. In its original configuration, when the engagement lever for the starter crank was engaged, a series of linkages retarded the timing on two of the Watford mags. Once the engine fired, the engagement lever automatically disengaged and returned the timing to its advanced position. The original system also featured a crank magneto for the booster as opposed to the battery system currently used.

The engine warmup takes about five minutes. Water temperature comes up within two minutes, but the oil temperature takes a little longer.