History of the CV1J4 Gyro Instrument Protection Kits CV1J4-C  (Cessna Kit) CV1J4-P  (Piper Kit) CV-700 Pneumatic Test Kit

 

 

 

History of the CV1J4

The CV1J4 “Clear View” Inline air filter was created in reply to comments from aircraft owners concerning the expensive practice of changing the old 1J4-6 and 1J4-7 metal can filters based on time requirements rather than necessity.

The CV1J4 “Clear View Filter is
FAA approved on a
“ Change Only As Needed”
Basis.

A very important second reason for the “Clear View” Filter development was the need for monitoring air pump deterioration in an effort to reduce or eliminate air pump failures during instrument flight conditions.

It is a well-known fact that the two most common reasons for air pump failure is old age and high system pressure (sometimes called “pump, back pressure”).

As an air pump accumulates operating hours, increased internal wear of the pump bore, along with the carbon rotor and vanes will occur. As the wear on these components increases the carbon dust discharged from the air pump also increases. If this warning sign is not noticed, or is ignored, air pump failure will occur be it on the flight line or at 10,000 feet.

The pressure produced by the air pump to provide adequate gyro instrument and/or aircraft de-icing operation is not normally monitored by a pressure gage in the instrument panel. With the system regulator maintaining the OEM recommended 4.7 to 5.2” hg (2.35 to 2.6 psi) any malfunction in the system that would cause an overload on the air pump will never be noticed. More pressure on the pump equals more internal wear, equals more carbon dust discharge.

With the CV1J4 “Clear View” Inline Filter installed
any increase in carbon dust being exhausted from the air pump
is clearly visible at every pre-flight or post-flight inspection.

The CV1J4 “Clear View” Filter is provided with a visual scale for comparison of internal contamination. When installed in a properly operating system the CV1J4 filter will last the life of the air pump and in fact is;

“Guaranteed For The Life Of The Air Pump”.

FAA-PMA Approved
For Installation On The Following Aircraft

Beechcraft:

Gulfstream: GA-7

Mooney: M20J, M20K and M20M

Piper: PA-31, PA-31P, PA-31-300,
PA-31-325, PA-31-350, PA-31P-350,
PA-31T2, and PA-34-200T

Twin Commander : 700

Standard equipment on all Mooney Aircraft since 1995:

Model M20M (Bravo)
Model M20R (Ovation)
Model M20S (Eagle)

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Gyro Instrument Protection Kits

While the original intent of the CV1J4 "Clear View" Inline filter was to replace the old style metal can 1J4-6 and 1J4-7 filters in pressure pneumatic systems, new applications appeared right around the corner.

It was known for some time that air pump failure in a "vacuum" instrument gyro system would eventually cause the failure or inaccurate operation of the aircraft's gyro instruments.  The many instrument repair stations throughout the country that overhaul or replace gyro instruments contaminated with carbon dust can support this as a certainty. 

During flight, positive pressure is created in the engine compartment via the ram air entering the front cowl.  Normal operation of the air pump creates a constant vacuum in the system lines in each gyro instrument.  With constant rotation of the pump rotor any carbon dust produced from normal (or abnormal) wear is exhausted into the engine compartment.  

Air Flow During Normal Operation

When pump failure occurs during engine operation the pump coupling separates to prevent damage to the internal parts of your engine.  Just prior to the rotor binding and coupling separation however, it is not uncommon for the rotor and vanes to fragment into small pieces creating large amounts of carbon dust. 

With a vacuum still present in the gyro instruments and connecting lines, along with the positive pressure in the engine compartment, this carbon dust can be moved backward, past the vacuum regulator and into both gyro instruments. (Ref Fig. 2)

Air Flow Caused By Air Pump Failure

In the early 90's, Mooney Aircraft Corporation began installing a filter between the air pump and vacuum regulator to prevent gyro instrument failure caused by carbon contamination and eliminate high replacement costs for the aircraft owner. 

Gyro Instrument Protection

Figure 3

The CV1J4 "Clear View Filter has been provided for gyro instrument protection on all Mooney Aircraft since October, 1995.

Air pump failures are expensive, not to mention the time and expense involved with possible gyro instrument replacement down the road.  Installation of an inline filter in vacuum gyro systems is a practical idea overlooked (or ignored) by most aircraft manufactures.

Gyro protection for Cessna and Piper single engine aircraft has just been made easier with installation of the CV1J4-C and CV1J4-P kits.  For a complete list of aircraft FAA-PMA approved for CV1J4 gyro protection, click on your model aircraft below.

CESSNA                         PIPER

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Cessna

If your aircraft is not listed above, contact Aerotech Components, Inc. for additional information.

Each Gyro Protection Kit is provided with clear installation instructions, photos, log book entry data and a copy of  FAA STC  # SA475CH.

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Piper

If your aircraft is not listed above, contact Aerotech Components, Inc. for additional information.

Each Gyro Protection Kit is provided with clear installation instructions, photos, log book entry data and a copy of  FAA STC # SA559CH.

Cv-700 Pnuematic Test kit

Air Pump Failures Don’t just Happen…..

They Are Caused….

By Mis-Adjusted Regulators And Defective Pneumatic Systems!

The “Clear View” CV-700 Pneumatic Test Kit provides the proper tools and information for testing aircraft gyro instrument and de-icing systems from a shop air supply. The dangerous situation of testing aircraft systems with a running engine and spinning prop has been eliminated.

Are you failing air pumps faster than popcorn pops in a hot skillet?

“Vacuum” and “Pressure” pneumatic systems can be checked for proper operation in less time than it takes to remove the engine cowling. Test the system, locate the problem and replace bad components before installing the next air pump!

The 70 page CV-700 “Clear View” Test Manual contains step-by-step instructions for testing aircraft gyro instrument, de-icing and autopilot systems. Additional diagrams of vacuum and pressure valves, regulators and de-ice control valves are provided with construction, operation and troubleshooting details never before available to the aircraft mechanic.

The “Clear View” CV-700 Pneumatic Test Kit costs less than the price of a new air pump and is a great investment for the FBO servicing twin engine aircraft or the flying club maintaining a fleet of single engine trainers.

Running the aircraft engine to check gyro instrument “pressure” or “vacuum” only confirms the needle on the gage hasn’t fallen off….

Testing the aircraft system with the “Clear View” CV-700 Pneumatic Test Kit will identify system malfunctions that lead to in-flight premature air pump failures.

CV-700 Pneumatic Test Kit Additional Features

Rugged reinforced aluminum carrying case with additional tool carrying capabilities. (Includes shoulder strap)

Two year free warranty on all components.

One year free customer assistance with all aircraft pneumatic system troubleshooting.

One year free update on all manual revisions and additions.

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