Citation Spring 2002

• Pulse Light Modifications
• Freon Air Conditioner Upgrades
• Fuel Panel Installation
• Lead Acid Battery Installation for 550s & 560s

Pulse Light Modifications

— Joe Austin

Precise flight has developed a control box which can be hooked into the tail logo lights and will then cycle in sequence with landing and recognition lights. It is a sixchannel unit, model number 2401. This box can also take input from the TCAS controller; this allows the unit to operate the pulse light system when a TCAS advisory is displayed, with the intent of making your aircraft more visible during the advisory.

The new control box is the same size as the original, so structural modification to the airframe is not required. Wiring changes are made using wiring prints available through Precise Flight and approved under a 337 document.

One of the benefits of the pulse light system has always been the “soft start” that it gives to the bulb when commanded to illuminate. This “soft start” function helps extend the life of the bulb.

Pulse light switches may need to be added or changed to a different style on the instrument panel if you do not already have the system installed in your aircraft.

For more info, contact Dennis VanStrien in BTL at 800.525.2376 or Tim Klenke in LNK at 800.475.2611.

Freon Air Conditioner Upgrades

— Joe Austin

In other Duncan Intelligence publications, there have been articles about Freon Air Conditioning R12 to R134 system upgrades from Fort Worth Airworks. These upgrades have been very successful. One of the options offered when purchasing a new system was electric solenoid in the evaporator drain lines that exit out the belly. The solenoids close after takeoff to prevent excessive pressurization leaks.

Fort Worth Airworks has come up with a better solution to the problem. The new part is an inline check valve that closes with pressurization, but still allows a very small amount of air leakage to allow for continuous drainage. The relays, timer, and solenoids can be eliminated with the installation of this new part. The check valves will fit on any of the evaporators including the other STC air-conditioning evaporator installations.

Give us a call for more information on these check valves, contact Joe Austin at 800.525.2376 or Ed Johnson at 800.228.4277.

Fuel Panel Installation

— Joe Austin

When installing fuel access panels, make sure that you follow the torque values and lubricant listed in the manual. The manual states that a light coat of petroleum jelly on the seal is all that is needed. The brand name “Fuel lube” is not approved as a lubricant for the seal. Excessive lubricant of any type on the panel seal can “insulate” the panel and will not have proper electrical bonding when installed.

For more information, contact Joe Austin at 800.525.2376 or Ed Johnson at 800.228.4277.

Lead Acid Battery Installation for 550s & 560s

— Joe Austin

Cessna has released bulletins that give instruction on installing the lead acid battery in your plane. In the past, this procedure was done under an STC. There are pros and cons for having either the Ni-Cad or the lead acid battery installed in the plane. Only you can decide which battery (and associated maintenance) you want to have in your plane. The bulletins are SB550-24-38 and SB560-24-39.

For more information, contact Joe Austin at 800.525.2376 or Ed Johnson at 800.228.4277.

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