since 1940

Fluctuating fuel flow in Continental fuel injected aircraft engine

Continental Fuel Injected engines

Fuel discharging from leaking engine driven fuel pump seal. Reference Continental Service Bulletin CSB 01-1. To  quote from CSB 01-01 "Failure to comply with this service bulletin may result in a reduction in or loss of engine power.

Fluctuating fuel flow in Lycoming carbureted engine

Inspect your fuel pump for potential failure

SPECIAL AIRWORTHINESS INFORMATION BULLETIN

 

 

 

Aircraft Certification Service
Washington, DC
U.S. Department of Transportation
Federal Aviation Administration

 

 

No. NE-01-22

 

 

May 11, 2001

Introduction

This Special Airworthiness Information Bulletin (SAIB) alerts you an owner or operator of Textron Lycoming Division, AVCO Corporation (Textron Lycoming) O-235; O-290; O-340; (L)O and IO-320, -360, -540; AIO-320, -360; AEIO-320, -360, -540; HIO-360; and TO-360 series reciprocating engines, with fuel pumps, Part Number (P/N) LW-15472, P/N LW-15473, or P/N LW-16335 installed, and that has one of the manufacturing date codes listed below as scribed on the edge of the pump mounting flange. See Figure 1.

These reciprocating engines are installed on but not limited to Aerospatiale, American Champion, Bellanca, Cessna, The New Piper Aircraft Company, Beech, Maule, Mooney, and Schweizer 269 series aircraft.

Background

Textron Lycoming has reported three events of high pressure fuel pump failures in their Production Test Cell. As of now, there have been no reported failures in the field and no way to predict when a failure may occur. The FAA is still investigating and if the situation changes, we may issue an Airworthiness Directive. These fuel pumps were either purchased as replacements or shipped from Textron Lycoming and installed on new, rebuilt and overhauled engines between September 18, 2000 and February 8, 2001 inclusive. The FAA recommends that you also check replacement fuel pumps received after February 8, 2001 whether they are installed or not.

Textron Lycoming issued their Service Bulletin (SB) No. 548 determining that several lots of diaphragm-type fuel pumps may have a potential for an internal failure. When an internal failure occurs, the check valve seat separates from its shaft due to an inadequate or improper assembly crimp. This allows the liberated parts to move within the housing and may cause a blockage of fuel flow. This failure may not be evident on the exterior of the pump, but it may result in a decrease or loss of fuel flow and a corresponding decrease or loss of power. Textron Lycoming estimates that approximately 1,252 fuel pumps were manufactured between September 18, 2000 and February 18, 2001 with a potential to fail, but they can not predict if or when the failure may occur.

Recommendations

To prevent a failure of the Textron Lycoming fuel pump, P/N LW-15472, LW-15473, or LW-16335, we highly recommend you inspect your engines for the applicable fuel pumps as shown in Figure 1 below and replace it as described in Textron Lycoming Service Bulletin (SB) No. 548. We recommend you should also check your maintenance records for affected replacement fuel pumps received after February 8, 2001.
· Textron Lycoming engine that has a diaphragm-type fuel pump, Lycoming P/N LW-15472,
LW-15473, or LW-16335 installed, with one of the following date codes in the 6 th through
9 th digit locations scribed on the pump:

3900 4000 4100 4200 4300 4400
4500 4600 4700 4800 4900 5000
5100 5200 0101 0201 0301 0401

Example: 163354800 should be inspected and replaced as specified in Textron Lycoming Service Bulletin 548

· If the letter “A” is marked as a suffix to the date code, the pump has been repaired by the pump manufacturer and replacement is not necessary.
Figure 1

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