Transition to Light Sport Airplanes (LSA) Part 3

Flight Environment

The stick and rudder skills required for LSAs are the same stick and rudder skills required for any airplane. This section outlines areas that are unique to LSA airplanes – most skills learned in a standard airworthiness type certificated airplane are transferrable to LSAs; however, since LSAs can vary significantly in performance, equipment and systems, and construction, pilots must seek competent flight instruction and refer to the airplane’s POH for detailed and specific information prior to flight.

Preflight


The preflight inspection of any airplane is critical to mitigating flight risks. A pilot transitioning into an LSA should allow adequate time to become familiar with the airplane prior to a first flight. First, the pilot and flight instructor should review the POH and cover the airplane’s limitations, systems, performance, weight and balance, normal procedures, emergency procedures, and handling requirements. [Figure 1]

Figure 1. Pilot’s Operating Handbook for a LSA

Inside of the Airplane


Transitioning pilots find an LSA very familiar when conducting a preflight inspection; however, some preflight differences are worth pointing out. For example, many LSAs do not have adjustable seats but rather adjustable rudder pedals. [Figure 2] Often, LSA seats are in a fixed position. There are varied methods that LSA manufacturers have implemented for rudder pedal position adjustment. Some manufacturers use a simple removable pin while others use a knob near the rudder pedals for position adjustment. Shorter pilots may find that the adjustment range may not be sufficient for certain heights and an appropriate seat cushion may be required to have the proper range of rudder pedal movement. In addition, seats in some LSAs are in a semi-reclined position. The first time a pilot sits in a semi-reclining seat, it may seem somewhat unusual. A pilot should take time to get comfortable.

Figure 2. Adjustment lever for the rudder pedal position

Another area that transitioning pilots require familiarity is with the flight and engine controls. These may vary significantly from airplane model to airplane model. Some LSA airplanes use conventional control stick while others use a yoke. One manufacturer has combined the two types of controls in what has been termed a “stoke.” While this control may seem unique, it provides a completely natural feel for flight control. [Figure 3] Regardless of the flight controls, a full range of motion check of the flight controls is required. This means full forward to full forward left to full aft left to full aft right and then full forward right. Verify that each control surface moves freely and smoothly. On some LSAs, aileron control geometry, in an attempt to minimize adverse yaw, moves ailerons in a highly differential manner; a pilot may see very little “down” aileron when compared to the “up” aileron. Pilots should always verify the direction of control surface movement.

Figure 3. Stoke flight control with conventional engine controls

Elevator trim on many LSAs is electrically actuated with no mechanical trim adjustment available. [Figure 4] Depending on the airplane, trim position indication may be displayed on the EFIS or an LED or mechanical indicator. On electric trim systems, as it is with any airplane, it is important to ensure that the trim position is correctly set prior to takeoff. Because trim positioning/indicting systems vary widely in LSA airplanes, pilots should fully understand not only how to position the trim, but also how to respond to a trim-run-away condition. Part of the preflight inspection should include actuating the trim switch in both nose-up and nose-down directions, verifying that the trim disconnect (if equipped) is properly functioning, ensure that the trim system circuit breaker can disconnect the trim motor from operating, and then properly setting the takeoff trim position.

Figure 4. Trim control

Depending on the engine manufacturer, the engine controls may be completely familiar to a transitioning pilot (throttle, mixture, and carburetor heat); however, some engines have no mixture control or carburetor heat. Instead, there could be a throttle, a choke control, and carburetor preheater. Regardless, a pilot must become familiar with the specific engine installed and its operation. A transitioning pilot also needs to become comfortable with difference between conventional engine control knobs and LSAs. In standard airworthiness airplanes, control knobs are reasonably standardized; however, LSAs may use controls that are much larger or smaller in size.

If the LSA is equipped with an EFIS, the manufacturer’s EFIS Pilot Guide should be available for reference. In addition, the airplane POH likely has specific EFIS preflight procedures that must be completed. These checks are to verify that all internal tests are passed, that no red “Xs” are displayed, and that appropriate annunciators are illuminated. Some systems have a “reversionary” mode where the information from one display can be sent to another display. For example, should the Primary Flight Display (PFD) fail, information can be routed to the Multi-Function Display (MFD). Not all LSA EFIS systems are equipped with a MFD or reversionary capability, so it is important for a transitioning pilot to understand the system and limitations.

Fuel level in any airplane should be checked both visually and via the fuel level instrument or sight gauges. In LSAs, fuel level quantities can be shown on a wide range of technologies. Some models may have conventional float activated indictors while other may have the fuel level display on the EFIS with low-fuel alarm capability. It is not uncommon for an LSA airplane to have advanced EFIS technology for attitude and navigation information but have a simple sight gauge for fuel level indication. Fuel tank selection can also vary from simple on/off valves to a left/right selector. Fuel starvation remains a leading factor in aircraft accidents, which should be a reminder that when transitioning into a new airplane, time spent understanding the fuel system is time well spent.

A popular safety feature of some LSAs is a ballistic parachute. [Figure 5] These devices have been shown to be well worth their cost in the remote case of a catastrophic failure or some other unsurvivable emergency. This system rockets a parachute into deployment and then the parachute slowly lowers the aircraft. The preflight inspections of these systems require a check of the mounts, safety pin and flag, and the activation handle and cable. Because most standard airworthiness type certificated airplanes do not have these systems installed, LSA training should cover the operation and limitations of the system.

Figure 5. A ballistic recovery parachute is a popular safety feature available on some LSA

Outside of the Airplane


Transitioning pilots should feel comfortable and in a familiar setting when preflighting the outside of an LSA. Some unique areas worthy of notation are presented below.

Propellers of LSAs may range from a conventional metal propeller to composite or wood. The preflight inspection is similar regardless of the type of propeller; however, if a transitioning pilot is principally familiar with metal propellers, time should be spent with the LSA flight instructor covering the type of propeller installed. Many LSA propellers are composite and have a ground adjustable pitch adjustment. As a result, there may be more areas to check with these types of propellers. For example, on ground adjustable propellers, ensure that the blades are tight against the hub by snugly twisting the blade at the root to verify that there is no rotation of the blade at the hub.

Many LSAs are equipped with engines that have a water cooling system. LSAs may be tightly cowled, which reduces drag, and with liquid-cooled engines, this minimizes the need for cylinder cooling inlets, which further reduces drag and improves performance. This does present a new system for a transitioning pilot to check. Preflighting this system requires that the radiator, coolant hoses, and expansion tank are checked for condition, freedom from leaks, and coolant level requirements. Most standard type certificated airplanes do not have coolant systems.

Split flaps may be used on some LSA designs. [Figure 6] These flaps hinge down from underneath the wing and inspecting these flaps require the pilot to crouch and twist low for inspection. A suitable handheld mirror can facilitate inspection without undue twisting and bending. In an attempt to keep complexity to a minimum, flap control is typically a handle that actuates the flaps. A pilot should verify that the flaps extend and retract smoothly.

Figure 6. Split flap

Before Start and Starting Engine


Once a pilot has completed the preflight inspection of the LSA, the pilot should properly seat themselves in the airplane ensuring that the rudder pedals can be exercised with full-range movement without over-reaching. Seat belts should be checked for proper position and security. The pilot must continue to use the POH for all required checklists. Starting newer generation LSA engines can be quite simple only requiring the pull of the choke and a twist of the ignition switch. If the LSA is equipped with a standard certificated engine, starting procedures are normal and routine. The canopy or doors of an LSA may have quite different latching mechanisms than standard airworthiness airplanes. Practice latching and unlatching the doors or canopy to ensure that understanding is complete. Having a gull-wing door or sliding canopy “pop” open in flight can become an emergency in seconds.

Taxi


Like standard certificated airplanes, LSAs may have a full-castoring or steerable nosewheel or, if conventional gear, a tailwheel. In order to taxi a full-castoring nosewheel equipped airplane, the use of differential brakes is required. This type of nosewheel can require practice to develop the skill necessary to keep the airplane on the centerline while minimizing brake application or damage to the tires. The balance is just enough taxi speed so that only light taps of brake pressure in the desired direction of turn or correction is required to make a turn or correction without carrying excessive taxi speed. If the speed is too slow, application of a brake can cause the aircraft to pivot to a stop, rather than an adjustment in direction, resulting in excessive brake and tire wear. If the speed is too fast, excessive brake wear is likely.

An LSA with conventional gear (tailwheel) should be initially transitioned into during no-wind conditions. The airplane, due to its light weight, requires the development of the proper flight control responses prior to operations in any substantial wind.

Takeoff and Climb


Takeoff and climb performance of LSA can be spirited as it typically has a high horsepower to weight ratio and accelerates quickly. Due to design requirement for low stall speeds, LSAs typically have low rotation and climb speeds with impressive climb rates. Like other airplanes, the pilot should be flying the published speeds as given the airplane’s POH. Stick (yoke or stoke) forces tend to be light, which may lead a transitioning pilot to initially over-control as a result of flight control deflections being greater than required. The key is to relax, have reasonable patience, and input only appropriate flight control pressures needed to get the required response. If a transitioning pilot is inducing excessive control inputs, they should minimize flight control pressures, set attitudes based on outside references, and allow the airplane to settle.

During climbs, visibility over the nose may be difficult in some LSAs. As always, it is important to properly clear the airspace for traffic and other hazards. Occasionally lowering the airplane’s nose to get a good look out toward the horizon is important for managing flight safety. Shallow banked turns in both directions of 10° to 20° also allow for clearing. Trim should be used to relieve climb flight control pressures that are generally light. Because flight control pressures tend to be light, it is easy to get in the habit of flying with an LSA airplane out of trim. This is to be avoided. Trim off any flight control pressures. This allows the pilot to focus as much time as possible looking outside.

Cruise


After leveling off at cruise altitude, the airplane should be allowed to accelerate to cruise speed, reduce power to cruise rpm, adjust pitch, and then trim off any flight control pressures. [Figure 7] The first time a transitioning pilot sees cruise rpm setting of 4,800 rpm (or as recommended), they may have a sense that the engine is turning too fast; however, remember that the engine has gear-reduction drive and the propeller is turning much slower. If the LSA is equipped with a standard aircraft engine, rpms are in a range that the transitioning pilot is immediately comfortable. The pilot should refer to the Cruise Checklist to ensure that the airplane is properly configured.

Figure 7. EFIS indication of level cruise flight

In slower cruise flight, stick forces are likely to be light; therefore, correction to pitch and roll attitudes should be made with light pressures. Excessive pressures result in the pilot inducing excessive correction causing a chasing effect. Only enough pressure needed to correct a deviation is required. This is best accomplished with fingertip pressures only and not with a wrapped palm of the hand. Stick forces can change dramatically as airspeed changes; for example, what could be considered light control pressures at 80 knots may become quite stiff at 100 knots. A CFI-S or CFI-A experienced in the LSA airplane is able to demonstrate this effect. This effect is dependent on the specific model of LSA and any significance or relevance varies from manufacturer to manufacturer.

LSA maneuvers such as steep turns, slow flight, and stalls are typically conventional. These maneuvers should be practiced as part of a good transition training program. Steep turns in LSA airplanes tend to be quite easy to perform precisely. With light flight control pressures, stick mounted trim (if installed), and highly differential ailerons (if part of the airplane’s design), makes the performance of the maneuver simpler than heavier airplanes. Basic aerodynamics applies to any airplane and factors, such as over-banking tendency, are still prevalent and must be compensated.

Slow flight in LSAs is accomplished at slower airspeeds than standard airworthiness airplanes since stall speeds tend to be well below the 45-knot limit. The first time practicing slow flight demonstrates the unique capability of LSAs. Power off stalls are typically of no particular significance as simply unloading the wing and the application of power immediately puts the airplane back flying. However, a pilot should understand that control pressures tend to be light so an aggressive forward movement of the elevator is generally not required. In addition, proper application of rudder to compensate for propeller forces is required, and retraction of any flap should be completed prior to reaching VFE, which comes very quickly if full power and nose down pitch attitude are maintained. Power on stalls can result in a very high nose-up attitude unless the airplane is adequately slowed down prior to the maneuver. In addition, some manufacturers limit pitch attitudes to 30° during power on stalls. If aggressive pitch attitudes are coupled with uncoordinated rudder inputs, spin entry is likely to be quick and aggressive.

Depending on the LSA design, especially those airplanes which use control tubes rather than wires and pulleys, flight in turbulence may couple motion to the stick rather distinctively. If a transitioning pilot’s flight experience is only with airplanes that have control cables and pulleys, the first flight in turbulence may be disconcerting; however, once the pilot becomes familiar with the control sensations induced by the turbulence, it only becomes another sign for the pilot to feel the airplane.

Approach and Landing


Approach and landing in an LSA is routine and comfortable. Speeds in the pattern tend to be in the 60-knot range, which makes for reasonable airspeeds to assess landing conditions. Flap limit airspeeds tend to be lower in LSAs than standard airworthiness airplanes so managing airspeed is important. Light control forces require smooth application of control pressures without over-controlling. Pitch and power are the same in an LSA as in a standard airworthiness airplane.

Crosswinds and gusty conditions can represent hazards for all airplanes; however, the lighter weights of LSA airplanes should place an emphasis in this area. Control application does not change for crosswind technique in an LSA. Manufacturers’ place a maximum demonstrated crosswind speed in the POH and, until sufficient practice and experience is gained in the airplane, a transitioning pilot should have personal minimums that do not approach the manufacturer’s demonstrated crosswind speed. The LSA’s light weight, slow landing speeds, and light control forces can result in a pilot inducing rapid control deflections that exceed the requirements to compensate for the crosswind. However, prompt and positive control inputs are necessary in strong winds. In addition, strong gusty crosswind conditions may exceed the airplane’s control capability resulting in loss of control during the landing.

Emergencies


LSAs can be advanced airplanes in regard to its engines, airframes, and instrumentation. This environment requires that a transitioning pilot thoroughly understand and be able to effectively respond to emergency requirements. While LSA are designed to be simple, a strong respect for system knowledge is required.

The airplane’s POH describes the appropriate responses to the various emergency situations that may be encountered. [Figure 8] Consider a few examples; the EFIS is displaying a “red X” across the airspeed tape, electric trim runaway, or control system failure. The pilot must be able to respond to immediate actions items from memory and locate emergency procedures quickly. In the example of trim runaway, the pilot needs to quickly assess the trim runaway condition, locate and depress the trim disconnect (if installed), or pull the trim power circuit breaker. Then depending on control forces required to maintain pitch attitude, the pilot may need to make a no-flap landing due to the flap pitching moments. Another example is failure of the EFIS. If the EFIS “blanks” out and POH recovery procedures do not reset the EFIS, an LSA pilot may have to be prepared to land without airspeed, altitude, or vertical speed information. An effective training program covers emergencies procedures.

Figure 8. Example of a POH Emergency Procedures section

Post-Flight


After the airplane has been shut-down, tied-down, and secured, the pilot should conduct a complete post-flight inspection. Any squawks or discrepancies should be noted and reported to maintenance. Transitioning pilots should insist on a training debriefing where critique and planning for the next lesson takes place. Documentation of the pilot’s progress should be noted on the student’s records.

Key Points

Many LSA’s have airframe designs that are conducive to high drag which, when combined with their low mass, results in low inertia. When attempting a crosswind landing in a high drag LSA, a rapid reduction in airspeed prior to touchdown may result in a loss of rudder and/or aileron control, which may push the aircraft off of the runway heading. This is because as the air slows across the control surfaces, the LSA’s controls become ineffective. To avoid loss of control, maintain airspeed during the approach to keep the air moving over the control surfaces until the aircraft is on the ground.

LSAs with an open cockpit, easy build characteristics, low cost, and simplicity of operation and maintenance tend to be less aerodynamic and, therefore, incur more drag. The powerplant in these aircraft usually provide excess power and exhibit desirable performance. However, when power is reduced, it may be necessary to lower the nose of the aircraft to a fairly low pitch attitude in order to maintain airspeed, especially during landings and engine failure.

If the pilot makes a power off approach to landing, the approach angle will be high and the landing flare will need to be close to the ground with minimum float. This is because the aircraft will lose airspeed quickly in the flare and will not float like a more efficiently designed aircraft. Too low of an airspeed during the landing flare may lead to insufficient energy to arrest the decent which may result in a hard landing. Maintaining power during the approach will result in a reduced angle of attack and will extend the landing flare allowing more time to make adjustments to the aircraft during the landing. Always remember that rapid power reductions require an equally rapid reduction in pitch attitude to maintain airspeed.

In the event of an engine failure in an LSA, quickly transition to the required nose-down flight attitude in order to maintain airspeed. For example, if the aircraft has a power-off glide angle of 30 degrees below the horizon, position the aircraft to a nose-down 30-degree attitude as quickly as possible. The higher the pitch attitude is when the engine failure occurs, the quicker the aircraft will lose airspeed and the more likely the aircraft is to stall. Should a stall occur, decrease the aircraft’s pitch attitude rapidly in order to increase airspeed to allow for a recovery. Stalls that occur at low altitudes are especially dangerous because the closer to the ground the stall occurs, the less time there is to recover. For this reason, when climbing at a low altitude, excessive pitch attitude is discouraged.

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