FEATHER FLETCHING – PART 1
Feathers are one of the wonders of Creation. They are constructed of a protein substance called keratin – a hard and very durable material. Feathers are a near-perfect adaptation for flight because they are lightweight, strong, aerodynamically shaped, and have an intricate structure of barbs and hooks (see Figure 1).
Figure 1 The structure of flight feathers
The proximal portion of the shaft (i.e. closer to the body), the quill, is hollow whereas the distal end (furthest from the body), is solid. The shaft bears two rows of branches, or barbs, which in turn support two rows of smaller, numerous barbules which cannot be observed with the naked eye but are clearly visible under a microscope. The barbules on the side of the barb towards the tip of the feather bear hooklets or barbicels, which form bridges with ridges on the adjacent proximal barbules. The barbules interlock tightly onto one another like a zip with the help of these hooklets and could be compared to Velcro. The vane is thus lightweight and pliable, but also extremely strong and resilient. If the hooklets come apart for any reason, the bird can easily restore the feathers to their original form by either shaking itself or by straightening its feathers out with its beak. Feathers also insulate the bird from heat and cold. Anyone who has slept under a goose down duvet or in a down sleeping bag will confirm how snug and warm they are even in icy cold weather. Feathers also have the ability to repel water.
The physical and structural properties of feathers – especially the wing and tail feathers of large birds such as eagles and turkeys – flexibility, inherent strength, light weight and rapid distortion recovery, make them excellent for arrow fletching, a fact discovered thousands of years ago. Although modern technology has provided us with strong, durable plastic fletching as an alternative to feathers there are those who would claim for reasons described below that feather fletching is superior.
I believe that arrows should be more than functional. Each arrow can be a work of art, with the fletching contributing significantly to the visual appeal of an arrow. The main function of a fletch is of course to stabilize the arrow in flight and to keep it on track towards the target. However, a highly colourful fletch is not only appealing to the appreciative eye but also provides a visual cue for the eye to follow during flight which can assist in seeing where an arrow hits and to find arrows that have ended up in the bush or grass (Figure 2). Flu-flu fletching is designed to slow an arrow down fairly quickly when shooting at aerial targets such as flying game birds (Figure 3).
Figure 2 Fletching should be more than just functional
Figure 3 Flu-flu arrow
Figure 4 Arrow velocity: feathers versus plastic (Mullaney & Holt)
Figure 5 Retained velocity downrange: feathers versus plastic (Mullaney & Holt)
Figure 6 Fletch recovery time for feathers
FEATHERS VERSUS PLASTIC FLETCHES
Let’s now compare the qualities and properties of feather and plastic fletching.
Feathers are faster
There are a number of reasons why feathers are faster than plastic vanes.
Feathers are much lighter than plastic vanes, as much as seven times lighter. This means less mass to accelerate and less energy wasted.
Feathers produce less friction as they come into contact with the arrow rest or other parts of the bow. Less friction equates to greater arrow velocity.
Feathers “steer” arrows better than plastic fletches. This produces less yawing and fishtailing of the arrow, which reduces drag. Drag has a significant effect on slowing down an arrow, so if there is less drag there will be more speed.
In independent tests feather-fletched arrows compared to identical shafts fletched with plastic vanes showed, on average, a velocity gain of about 5 fps (Figure 4). Tests conducted by bow experts Dave Holt and Norm Mullaney have also consistently shown that feather-fletched arrows maintain velocity better than plastic-fletched arrows at most “normal” hunting ranges (Figure 5). They concluded that, at normal hunting ranges, feather-fletched arrows travel faster, drop less and arrive sooner at the target than plastic fletched arrows.
Feathers are more effective guidance systems
Here again a number of factors come into play, causing feathers to steer arrows more effectively. The result is less fishtailing and yawing.
The surface of feathers is rougher than that of smooth plastic. This, for want of a better word, “grips” the airflow more effectively and quickly corrects any yawing or pitching tendencies (fishtailing/porpoising), resulting in rapid realignment.
The lighter weight improves stability. The more weight attached to the rear end of a shaft (i.e. heavier plastic vanes) the greater is the tendency of the shaft to want to “swap ends”.
When a feather-fletched arrow crosses the arrow rest (especially older type “shoot-through” rests) or makes contact with any part of the bow, feathers “collapse” or fold out of the way and then immediately recover back to their normal position once the obstacle has been passed. Even when severe contact is made with an arrow rest feathers recover within around 0.0047 seconds and after having travelled only 16 inches or 40.6 cm (Figure 6).This is also a big advantage if the fletch should contact a twig or leaf on its way to the target animal, i.e. brush deflection.
Plastic-fletched shafts “bounce” when the fletching encounters an obstacle, causing a significant deviation of the rear end of the shaft. This “swing” is aggravated by the plastic surface of the vane having less “grip” on the airflow. While the shaft is yawing or pitching it is being steered by aerodynamic forces off its original path and the arrow is no longer going where it was originally aimed. A feather-fletched arrow can be nocked incorrectly with the cock vane making contact with the riser and it will still fly straight. A plastic-fletched arrow will deviate significantly off course if the cock vane made contact with the riser. Plastic fletching also has a much slower recovery when it is distorted. The distorted shape will exert a longer negative effect on the shaft flight than occurs in the quick recovery of feathers. Plastic vanes are thus “sluggish” in correcting arrow flight.
Feather-fletched arrows are more forgiving.
When the advantages mentioned above are combined, the result is that the arrow fletched with feathers will tolerate and be more accommodating of a wide range of bow and shaft variables as well as shooting form. Arrow rests, bow draw weight, release aids, shaft spines, small lapses in shooting form and so on all become much less critical. Feather fletching to a greater degree than plastic fletching, while not eliminating, will help offset and compensate for bow, shooting form and shaft variables and result in more “forgiving” arrows. Some hunters shoot feather-fletched arrows directly “off the shelf” without a rest.
Feather-fletched arrows are less adversely affected by extreme temperatures.
Feathers are not affected by ultraviolet rays. Plastic hardens and becomes brittle over time when subjected to the sun’s rays.
Feathers are ecologically more acceptable because they are biodegradable. Plastic takes a long time in nature to break down.
The one BIG plus for plastic fletches is cost. They are significantly cheaper and more easily obtainable than feather fletching. Plastic fletches work acceptably well, but when it comes to the small matters there are many who say that feathers have the edge.
Two more disadvantages of feathers are that they are not as durable as plastic fletches and they are susceptible to some insects that can feed on and damage them.
In Part 2 we will look at making your own feather fletches.