Trike Performance and Flight Characteristics FAQ
1. How do trikes stall?
Stalling the wing of a trike is an easy, gentle, and forgiving maneuver. The wing’s “nose” is at a higher angle of attack than the wingtips. At high angles of attack the nose buffets first, loses lift, and naturally falls through while the tips in back keep flying. This factor results in a stall-resistant aircraft.
The high angles of attack has the nose section of the trike stall first allowing the nose to drop first, providing a stall resistant wing.
2. What about different speed trikes and what is their range?
Traditionally, trikes have flown in the slow-30-40 mph cruise and 25 mph stall-and medium-40-60 mph cruise and 30 mph stall-speed ranges. With newer wings and larger engines, trikes are now moving into the fast speed range, cruising at 70 to 90 mph. The wing’s size affects speed. A trike with a large 19-meter wing (200 square feet) will fly slowly. A 16-meter wing (170 square feet) gives you the medium speed range. And a small wing, 11 meters (115 square feet), provides the fast speeds range.
A trike carriage can be fitted with different wings, which means you can easily expand your flying options by having more than one size wing. Generally, the wing represents about 25 percent of the trike’s total cost, but smaller wings generally need more engine power. New trikes currently being tested have enclosed cockpits to keep the wind off you at higher speeds. We will see trikes evolve into higher speed machines considering creature comfort and fuel efficiency.
Speed is one part of the range equation. Endurance-how much time you have in the fuel tank-is the other. A trike cruising at 60 mph for three hours will travel roughly 180 miles-unless it’s flying into a head wind, which reduces the distance. Trikes are powered by two- or four-cycle engines. With the same fuel capacity, four-cycle engines give better range because they use significantly less fuel than the two-cycle engines.
Speed ranges for PPC, Trikes and airplanes.
3. How do trikes handle the wind, crosswinds, and turbulence?
Generally, an intermediate or advanced trike pilot can fly in a head wind that’s about two-thirds your stall speed and a crosswind of one-half your stall speed. Trikes and fixed-wing aircraft can taxi, take off, and land in comparable crosswind conditions.
The configuration and size of the wing affects crosswind capabilities for both types of aircraft. Higher-speed aircraft typically have greater crosswind capabilities because higher speeds mean less crab angle on approach. To land a trike in a crosswind, you line up on the runway centerline naturally crabbed into the wind and fly it crabbed to touchdown. As your back wheels touch, the nose wheel swings around straight down the runway.
Crosswind takeoffs are similar. When you lift off the runway, the wing naturally weathervanes into the wind set-ting up a crab angle for you to proceed directly down the centerline of the runway. Naturally, each pilot’s wind limits depend on his or her experience.
Cross wing takeoff
Cross wind landing
In turbulence, the wing moves more than the undercarriage resulting in less bumping around. Because the weight is under the wing, the undercarriage naturally wants to seek level flight. In moderate to severe turbulence you must hold onto the bar, which takes some muscle and can be fatiguing on long flights.
4. What is the performance of a trike – How fast do trikes climb and how high can they go?
Trikes have an advantage over airplanes-no tail-meaning they are not burdened by the weight, drag, and down-force associated with the tail structure. This gives trikes better climb rates and the ability to carry greater loads.
For example, with a small but efficient 50-hp engine, my medium-wing trike, one person, climbs 1,000 feet per minute at sea level, and (with oxygen) I’ve climbed to 17,000 feet. Fully loaded with two people, I climb at 500 fpm at sea level and can reach 11,000 feet.
Trike at 11,000 feet over Lake Tahoe
In this configuration of small engine, low drag, and medium wing, the trike stalls at 30 mph, flies hands-off at 45 mph, and has a maximum cruise of 65 mph. A large engine (100 hp) on a single-seat carriage with a smaller wing (12 meters) climbs at 60 mph and 2,000 fpm. Your speed, climb rate, and service ceiling depend on your configuration.
5. How do trikes perform with the engine shut off?
Trikes are efficient aircraft and glide nicely at about a 6-to-l glide ratio with the engine shut off. It is common practice to cut power and land on a spot.
Glide ratio for a trike is about 6 to 1. The higher you fly the more square miles you have for an emergency landing.
6. How easy is it to fly a trike?
First, it’s important to understand that a trike is trimmed to fly at a certain speed (we’ll use 45 mph, since it is where my trike is trimmed). In calm air you can let go of the controls and the trike will fly generally straight and seek the trim speed designed into the aircraft. Just as is in cars and airplanes, flying hands off requires slight corrections in direction.
For airplanes, flying requires 3 axis of control: 1 ailerons (roll); 2elevators (pitch); and 3 rudder (yaw)-controlled by a stick/yoke and rudder pedals. The trike has two axes-roll and pitch-that are controlled by a bar connected to the wing. The design of the trike’s swept wing, with a certain amount of twist and airfoil shape, provides automatic yaw control. In other words, trikes are comparatively easy to fly verses airplanes because you are only controlling two axes rather than three axes.
An easy touch on the controls is the key to learning to fly a trike. When you shift your weight to one side of the trike, it warps the wing by providing more twist on one side than the other. Similar to the Wright brothers’ “wing warping”, the increased twist generates less lift on that side, and more lift on the other side which produces roll.
Shifting the weight to the right creates more twist on the right side, and less twist in the left side thus rolling the trike to the right.
In the 1980s, when hang gliders evolved from crude delta wings to flying wings, the “floating crossbar” or “floating keel” (the keel is allowed to move side to side in relation to the frame) allowing greater wing warping or power steering. This floating cross bar became the industry standard control system. This simple wing warping is the key to the weight-shift wing efficiency and rapid roll response. To pitch the nose up you simply push on the bar, and you pull it toward you to pitch the nose down. Control is intuitive because you have hold of the wing, and it goes wherever you move it. The motions are similar to riding a bicycle or motorcycle.
7. What about transitioning from stick and rudder (airplane) or PPC to weight shift?
Airplane and trike controls are different, so airplane pilots will have to “unlearn” their stick and rudder skills when learning to fly a trike. Adding to the difference is the sitting in the open and the loss of the airplane’s “window” reference to the horizon.
Typically, airplane pilots feel disoriented for the first 20 minutes and must think about the necessary control inputs for the first hour or two. Normally, airplane pilots are comfortable flying trikes after about two hours in the air, and many have developed the proper “habits” and are ready to solo after five hours. These are general observations based only on my experience. Some pilots pick it up immediately, and others take a little longer. It is no big deal to learn to “fly the wing” rather than move and coordinate the controls.
Powered Parachute pilots have similar roll control, pull in the direction where you want to go, so the roll comes easier for the PPC. The added tasks are speed, slow flight, fast speed and stalls.
The number of axis control results in greater learning time. Airplane is three axis, Trike is two axis, and PPC is one axis.
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