Home: Products & Solutions: Fault Prevention

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• Electrical fault conditions
• Extended dry-operation
• Mechanical interference / degradation

UFI Installed with Relay Adapter Module

Due to its low cost, light weight and high reliability, the UFI is quickly becoming the solution of choice for operators seeking compliance with center tank SFAR 88 mandates. UFI was approved for installation on B737-300 aircraft per STC# ST01844LA.  

In cooperation with our airline partners, TDG is currently developing and certifying UFI installation kits for the remaining Boeing fleets - providing our customers an elegant alternative to expensive and cumbersome aircraft modification solutions.   UFI installations can be accomplished during normal overnight visits (737-300 installation is plug-and-play, installing in a matter of minutes). These certification efforts are aimed specifically at eliminating the minimum fuel restrictions of ADs 2002-24-51 and 2001-15-08.

Those operators that do not have the maintenance resources to rapidly implement UFI on their aircraft are encouraged to contact American Airlines Maintenance Services (www.mroaa.com). American Airlines engineering and maintenance personnel have been extensively involved in the certification of UFI technology and are uniquely positioned to ensure that installation efforts are efficient and fully compliant with the STC.

Electrical Fault Protection

The UFI reliably detects line-to-ground and line-to-line faults in the boost pump wire harness or pump motor windings.  It will also detect intermittent opens in the wire harness, connectors or pump motor.

Extended Pump Dry-Operation

Making use of the unique current / voltage signature generated when a synchronous motor is no longer doing work, the UFI can detect when the fuel boost pump inlet is uncovered and the pump is no longer moving fuel.  Based upon regulatory guidance, the UFI will allow this condition to persist uninterrupted for fifteen (15) seconds before removing power from the boost pump.  

Mechanical Interference

Because the UFI is independently monitoring current and voltage on each phase, it can also identify the increased current draw that is associated with mechanical interference or wear conditions within the pump motor.  For example, progressive bearing failure within the pump will demand increased levels of current in order to maintain normal operation, especially during pump start-up.  Similarly, mechanical interference due to impeller/housing contact or impeller FOD ingestion is detectable by the UFI.

REFER TO FAA ADVISORY CIRCULAR AC 25.981-1B FOR DISCUSSION OF IDENTIFIED UNSAFE CONDITIONS WITH RESPECT TO AIRCRAFT FUEL BOOST PUMP SYSTEMS ( SEE DOWNLOADS PAGE).

Downloadable Database

The UFI utilizes a non-volatile database to record pump operational parameters and fault information for use by maintenance personnel in troubleshooting fault conditions or accomplishing preventative maintenance.  Information such as maximum startup currents, historical average current / voltage on each phase and specific fault data could be invaluable to maintenance or reliability personnel.  The UFI hooks directly to a laptop computer and provides the relevant information in an easy-to-use data retrieval format that may be saved to a PC or printed for future reference.

Click here to be taken to the TDG Aerospace Downloads page, where additional information and technical specifications can be found in our published UFI literature.