As any avionics technician can well attest, one of the major problems in avionics has been that equipment that performs flawlessly in the service bench often fails when reinstalled in the aircraft. This usually involves connector or wiring harness failures, a particularly difficult thing to service for the technician who is faced with working in hard-to-reach places, and expensive to the aircraft operator because the aircraft is tied up during this service. Stabilant 22 has become the product of choice for many organizations in the industry to mitigate these problems.

 

The use of computer chips and other integrated circuits has enabled avionic equipment manufacturers to introduce new features, while reducing the size of the equipment, power draw, and installations package count. Due to complexity, these improvements have not been totally problem free.

 

While some of the connector problems have been moved from the aircraft harness into the equipment itself, the complexity of the circuitry together with the very low current levels in the contacts resulted in increased connector-related service problems.

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Microprocessors in avionics have allowed implementation of many new features simply by updating the internal software. In the years before flash memories entered widespread use, replaceable (socketed) ROM/EPROM IC’s were used, making this type of system more prone to "crashing" because of socket contact problems. The older Loran-C receivers, for example required EPROM-based databases that would be updated periodically in order to accommodate new frequencies, or other airport or nav-aid information. Even in the 21st century, with GPS and satellite navigation taking over, Loran-C systems are maintained as a backup; some receivers were still on sale as of 2023.

 

In the environment of vibration and cyclic pressure/temperature changes, IC and memory module sockets, as with most aviation connectors, are much more prone to contaminant penetration than those in stationary installations.

 

Stabilant products have been used since the 1980’s to overcome these problems. The opportunity to increase contact reliability in this environment is a result of several factors. Vibrations cause small relative movements of components, degrading contact surfaces due to "stiction" effects and creeping corrosion or contaminant films. These compounding effects increase resistance and lead to contact failure. Even before an obvious failure occurs, these produce intermittent troubles, including microphonics - the introduction of spurious signals directly from the vibrations. Some corrosion byproducts can also cause rectification effects, which can alter waveforms, change critical timings, and make the equipment prone to RF interference.

 

Stabilant 22 replaces older contact lubricants. It does not suffer from varnishing due to catalytic cross-linking as would those with unsaturated oils. It provides a longer lasting solution, including chemical stability and a surfactant property that keeps existing contaminants from adhering to the contact surfaces. The electrically active properties of the product counter the rectification effects commonly produced by penetration corrosion films. And, of course, the Stabilant film surrounding the contact interface prevents external contaminants from entering the interstices of the contacts.

 

Stabilant 22 thus substantially improves the reliability of multiple (interdependent) package installations as well as improve the reliability of single package units. With the increasing costs of avionics service the savings can be considerable.

 

In instrument landing systems, Stabilant treatment has been proven to cure most connector related problems, especially where the operating environment is less than ideal. This is also true of VOR's, VORTAC's, NDB's and marine beacons. Often these navigational aids are located in remote, difficult-to-access places where a major part of the maintenance time is just getting to and from the site. Added to these costs is the work of verifying function and calibration of the repaired systems.

 

Many navigational aids are more likely to fail under severe weather conditions, which is often when they are needed most. When connections are less than perfect, the system more is more susceptible to RF interference and the electromagnetic pulse effects of lightning. We have even been told that some stations are applying Stabilant 22 to the pins as well as to the finger stock contacts used on transmitting tubes in order to reduce parasitics.

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With the increasing sophistication of the equipment, the power levels of the individual circuits have been substantially reduced, conserving energy, and minimizing heat dissipation requirements. This involves components operating at much lower current levels, and thin film contamination effects are proportionally more important in determining reliability of the connections.

 

The number of connections in most systems has also increased substantially. And while microprocessor control is now making it easier to perform self-checks on some of the new equipment, increasing connector pin counts have made the same equipment more sensitive to all types of connector problems. Stabilant 22 treatment mitigates the well known effect of increased complexity leading to increased failure rate.