LASAR Flight Manual Supplement

SCOPE:  This supplement must be attached to the FAA Approved Airplane Flight Manual when the LASAR® System is installed. The information contained herein supplements or supersedes information of the basic Airplane Flight Manual only in those areas listed. For limitations, procedures, and performance data not contained in this supplement, consult the basic Airplane Flight Manual.

FLIGHT MANUAL SUPPLEMENT APPLICABILITY

This Flight Manual Supplement is applicable to aircraft equipped with Unison's LASAR® system.

2. GENERAL

LASAR® is the integration of microelectronics with traditional magnetos to provide controllable ignition for optimizing engine performance, while providing dual mechanical backup ignition for redundancy and safety.

The LASAR® system provides ignition in either an automatic or default/backup mode. Operating procedures of the airplane in either the automatic or default/backup mode are identical to an airplane with a conventional magneto ignition system as described in the original flight manual.

Some airframe installations include an enunciator light mounted in the cockpit which becomes illuminated when the LASAR® system is operating in the default/backup mode or when the controller is receiving input power while the engine is not running.

Automatic Mode:

When operating in the automatic mode, the LASAR® system senses engine manifold pressure, crankshaft speed, and other engine parameters, then selects the optimum ignition timing angle and spark energy from a three dimensional map programmed into the system software. The LASAR® system operates in the automatic mode when the cockpit ignition switch is in the "BOTH" position, the system is receiving adequate electrical power and internal system diagnostics determine that the system is fully functional. During automatic mode operation with the engine running, the cockpit enunciator light (if equipped) will not be illuminated. Starting the engine on the ground requires the LASAR® ignition system to be operating in the automatic mode.

Automatic timing advance from the LASAR® system may cause cylinder head temperatures (CHTs) to increase as fuel is burned more efficiently within the combustion chamber. Incremental CHT rise due to ignition timing advance from a non-CHT controlled LASAR® system is typically 20°F. To accommodate LASAR® system installations on airframes with marginal engine cooling or on airframes where engine cooling characteristics have not been determined, LASAR® systems are offered with CHT control circuitry that incrementally reduces the timing advance angle as CHTs approach a preset maximum limit, thereby reducing CHT rise due to advanced ignition timing. If ignition timing advance is reduced by the CHT control feature, engine performance improvements resulting from optimized ignition timing will be reduced. In extreme situations where the engine continually operates at maximum cylinder head temperatures, LASAR® will command the same ignition timing as provided by conventional magnetos, resulting in comparable engine performance.

Two different limits (climb and cruise) are used to control CHT rise due to ignition timing advance. These limits vary between installations and are preprogrammed into the LASAR® controller software. During engine operation, the LASAR® system initially selects the climb limit whenever power is first applied to the controller. The climb limit remains selected until a 15 minute timer expires. The 15 minute timer begins to count when CHT exceeds the cruise limit for the first time. Once the 15 minute timer expires, the cruise CHT limit remains selected, including subsequent climbs.

Default/Backup Mode:

When operating in the default/backup mode the LASAR® system provides traditional magneto ignition. The LASAR® system automatically switches to the default/backup mode when the system receives inadequate electrical power, or internal system diagnostics detects a hardware or software fault. The system may be manually switched to default/backup operation by turning the ignition switch to the "LEFT" or "RIGHT" position. Engine performance in the default/backup mode is identical to engine performance with traditional magnetos. During default/ backup mode operation the LASAR® controller provides a ground return path for the cockpit enunciator light (if equipped) which becomes illuminated provided the light is receiving adequate input power. To restart the engine in-flight with the LASAR® ignition system operating in the default/backup mode, windmill the engine above 500 rpm.

Preflight Magneto Check Logic:

A preflight magneto check initiates comprehensive hardware and software tests of the LASAR® system, including default/ backup magneto operation. When the ignition switch is turned from the "BOTH" position to the "LEFT" or "RIGHT" position, the system automatically switches the selected magneto to default/backup operation and if equipped, the cockpit enunciator light becomes illuminated. When the ignition switch is returned to the "BOTH" position, the system remains in default/backup operation for approximately 20 seconds to facilitate engine RPM drop comparison. After the ignition switch has been in the "BOTH" position for more than 20 seconds, the system automatically switches to automatic mode operation and the cockpit enunciator light, if equipped will turn off. Proper functioning of the cockpit enunciator light should be confirmed each time a preflight magneto check is performed. Preflight magneto check PASS/FAIL criteria is identical to that of conventional magneto ignition systems.

Mixture Leaning:

Increased combustion efficiencies from the LASAR® system may result in higher cylinder head temperatures (CHT). Follow the mixture leaning procedures contained in the original flight manual to maintain CHT below the maximum limit.

3. LIMITATIONS

A. Engine Limits

The LASAR® system is for use with engines using 100 LL Avgas only.

B. PropellerNo Change
C. Power Plant InstrumentsNo Change
D. Ground HandlingCAUTION

THE LASAR® SYSTEM IS ARMED AND READY TO FIRE AT ENGINE TDC WHEN THE IGNITION SWITCH IS IN THE "BOTH" OR "START" POSITION AND THE MASTER SWITCH IS "ON." FORWARD OR REVERSE MOVEMENT OF THE PROPELLER MAY TRIGGER AN IGNITION EVENT. DO NOT MOVE PROPELLER BY HAND WHEN THE IGNITION SWITCH IS IN THE "BOTH" OR "START" POSITION AND THE MASTER SWITCH IS "ON."

4. PROCEDURES

Operating procedures for aircraft equipped with a LASAR® system are identical to the operating procedures of the same aircraft with a conventional magneto ignition system as described in the original flight manual.

Illumination of the cockpit enunciator light (if equipped) with the ignition switch in the both position with the engine running indicates that the LASAR® system has automatically switched to default/backup operation and that the LASAR® system requires service prior to the next flight. If the cockpit enunciator light does not illuminate properly during a preflight magneto check, service the LASAR® system or the enunciator light and input power circuit prior to the next flight.

5. EMERGENCY PROCEDURES

No Change

6. PERFORMANCE

The performance of the airplane when equipped with a LASAR® system can be equal to or better than the performance listed in the original flight manual.

CAUTION:NEVER FACTOR IN ANY IMPROVEMENT RESULTING FROM A LASAR® SYSTEM IN FLIGHT PLANNING, AS THESE IMPROVEMENTS WILL VARY FROM FLIGHT TO FLIGHT DEPENDING ON THE FLIGHT PROFILE AND MIXTURE LEANING PROCEDURE.