Advanced Ignition for the 21st Century — Installing the LASAR Electronic Ignition System — Part II
By Harry Fenton
An overview of the LASAR® electronic ignition system was provided in the May/June 2001 issue of AMT. This article, the second and last in the series, outlines a LASAR installation recently completed by Unison.
The subject aircraft of this installation, a Wag-Aero Sportsman, is an amateur built rendition of a Piper PA-14 Family Cruiser, somewhat of a four-place version of a Piper Cub. While not representative of your garden-variety aircraft, the basic LASAR installation techniques are the same for most other single engine aircraft listed on Unison’s LASAR STCs. The installation will require about 3-4 hours of shop time, while LASAR systems with extra features such as CHT interface and cockpit enunciator lights will require about 5 hours or so. Keep in mind, advance planning and preparation will ensure that the installation will be accomplished in a timely manner.
The T-300 SynchroLASAR® is the only special installation tool required, but there are a few other commonly available tools that certainly speed the installation along. A #8 screw extractor, 1/4-in. drill bit, and a rivnut tool capable of inserting 10-32 rivnuts will prove to be significant time savers.
Prior to the installation, obtain the latest copy of LASAR Service Letter SL1-96 and review it thoroughly to understand parts selection and the installation procedures. Once again, pre-planning is key and having all of the major LASAR components, circuit breaker, hardware, pressure tubing and other incidentals on hand at the time of installation will help to ensure a trouble-free installation experience.
The open area on the firewall of the Sportsman is tight, but a location for the controller is found on the lower right side (as referenced from the pilot’s perspective). Preferably, the controller should be mounted with its manifold pressure port and electrical connector pointing downward, left, or right to prevent the connector from becoming contaminated. Given the location of the exhaust, the controller will be mounted so that the connector faces right.
Allowing for adequate slack, but not so much that there would be excessive length to the low voltage control harness (LVCH – sometimes called an "LH" harness), the distance from the back of the controller LVCH connection to the back of the left and right magnetos is measured. Using the LVCH selection chart found in the SL1-96, the correct length and part number for the LVCH harness are identified. In this installation, the correct part number is LH1004-17. Also, for this installation, we had the advantage of already having the controller and magnetos before measuring the correct length of the LVCH. To determine the correct length of the LVCH before procuring any of the LASAR components, first determine the exact controller location and orientation on the firewall. Then measure from the planned location of the controller’s electrical connector to the rear housing of both the left and right conventional magnetos. Follow the remaining instructions and chart in SL1-96 to identify the appropriate LVCH part number.
Based on a review of SL1-96 and the pre-work just described, the components ordered for installation on the Sportsman and Lycoming O-320-E3D combination can be found in Table 1.
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