DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 [58 FR 31647  NO. 106  06/04/93]

[Docket No. 93-ANE-16; Amendment 39-8584; AD 93-11-11]

Airworthiness Directives; AC, Textron Lycoming, and Rajay/Rotomaster-modified Diaphragm Fuel Pumps

AGENCY:  Federal Aviation Administration, DOT. 

ACTION:  Final rule, request for comments.

SUMMARY:  This amendment adopts a new airworthiness directive (AD) that is applicable to AC, Textron Lycoming, and Rajay/Rotomaster-modified diaphragm fuel pumps.  This action supersedes priority letter AD 93-05-21 that currently requires removal and replacement, prior to further flight, of all high pressure diaphragm fuel pumps overhauled by Aero Accessories Inc. (AAI) between June 18, 1991, and November 24, 1992; and removal and replacement, prior to further flight, of all low pressure diaphragm fuel pumps overhauled by AAI between November 1, 1991, and August 20, 1992.  This action clarifies that all affected high pressure diaphragm fuel pumps must be replaced, regardless of compliance with priority letter AD 92-20-07.  This amendment is prompted by the need to clear up a possible misinterpretation that affected high pressure diaphragm fuel pumps that have complied with priority letter AD 92-20-07 need not be replaced.  The actions specified by this AD are intended to prevent disruption of fuel flow to the engine, which can result in a loss of engine power.

DATES:  Effective June 21, 1993.
	Comments for inclusion in the Rules Docket must be received on or before August 3, 1993.

ADDRESSES:  Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Assistant Chief Counsel, Attention:  Rules Docket No. 93-ANE-16, 12 New England Executive Park, Burlington, MA 01803-5299.

FOR FURTHER INFORMATION CONTACT:  Jerry Robinette, Aerospace Engineer, Propulsion Branch, Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate, 1669 Phoenix Parkway, Suite 210C, Atlanta, GA 30349; telephone (404) 991-3810; fax (404) 991-3606. 

SUPPLEMENTARY INFORMATION:  On September 14, 1992, the Federal Aviation Administration (FAA) issued priority letter AD 92-20-07, to require removal and replacement, prior to further flight, of all diaphragm fuel pumps manufactured by AC or Textron Lycoming, and modified by Rajay/Rotomaster that were overhauled by Aero Accessories, Inc. (AAI) between November 1, 1991, and August 20, 1992.  That priority letter AD was prompted by a report of an aircraft accident caused by an obstructed high pressure diaphragm fuel pump.  Certain AC, Textron Lycoming, and Rajay/Rotomaster-modified diaphragm fuel pumps overhauled by AAI between November 1, 1991, and August 20, 1992, may contain a rubber washer manufactured from an improperly cured material.  The material can absorb fuel and expand, causing the washer to dislodge from its position and block off the outlet valve of the pump.  The FAA's investigation revealed three additional high pressure diaphragm fuel pumps with the washer dislodged.  That condition, if not corrected, can result in disruption of fuel flow to the engine, which can result in a loss of engine power.
	Since the issuance of priority letter AD 92-20-07, the FAA has received a report of an obstructed high pressure diaphragm fuel pump that resulted in a total loss of engine power due to fuel starvation.  This engine failure resulted in a power-off emergency forced landing.  The high pressure diaphragm fuel pump's outlet valve was blocked by a rubber washer that had been replaced in accordance with priority letter AD 92-20-07.  The FAA's further investigation has revealed that all rubber washers installed by AAI during overhaul between June 18, 1991, and November 24, 1992, are susceptible to fuel absorption and subsequent expansion.  On November 25, 1992, AAI began manufacturing washers composed of a rubber impregnated fabric that is more durable.
	Priority letter AD 92-20-07 required replacement of rubber washers manufactured from an improperly cured material with serviceable rubber washers.  However, the FAA has received no reports prior to or subsequent to the issuance of priority letter AD 92-20-07 of dislodged rubber washers on low pressure diaphragm fuel pumps.  The FAA has determined that these low pressure diaphragm fuel pumps do not create enough force to dislodge properly cured rubber washers.  Therefore, there is no need to replace properly cured rubber washers with rubber impregnated fabric washers on low pressure diaphragm fuel pumps.  No further action is required for low pressure diaphragm fuel pumps if the requirements of priority letter AD 92-20-07 have been previously accomplished.
	High pressure diaphragm fuel pumps, however, create sufficient force to dislodge the replacement rubber washers required by priority letter AD 92-20-07.  Therefore, priority letter AD 93-05-21, issued on March 17, 1993, superseded priority letter AD 92-20-07 to require removal and replacement, prior to further flight, of all affected high pressure diaphragm fuel pumps, regardless of compliance with priority letter AD 92-20-07.
	Since the issuance of priority letter AD 93-05-21, the FAA has determined that there is a need to clear up a possible misinterpretation that affected high pressure diaphragm fuel pumps that have complied with priority letter AD 92-20-07 need not be replaced.  This amendment clarifies that all affected high pressure diaphragm fuel pumps, regardless of compliance with priority letter AD 92-20-07, must be replaced prior to further flight.  No further action is required for all affected low pressure diaphragm fuel pumps that are in compliance with priority letter AD 92-20-07.
	In addition, low pressure diaphragm fuel pump serial number 91K125 was inadvertently repeated in the Applicability paragraph of priority letter AD 93-05-21.  The second reference to this serial number has been removed.
	Since the unsafe condition described is likely to exist or develop on other fuel pumps of the same type design, this AD supersedes priority letter AD 93-05-21 to prevent disruption of fuel flow to the engine, which can result in a loss of engine power.  The AD requires removal and replacement,prior to further flight, of all high pressure diaphragm fuel pumps overhauled by AAI between June 18, 1991, and November 24, 1992, regardless of compliance with priority letter AD 92-20-07; and removal and replacement, prior to further flight, of all low pressure diaphragm fuel pumps overhauled by AAI between November 1, 1991, and August 20, 1992, unless the requirements of priority letter AD 92-20-07 have been previously accomplished.
	Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited
	Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule.  Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire.  Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES."  All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received.  Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
	Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule.  All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons.  A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
	Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made:  "Comments to Docket Number 93-ANE-16."  The postcard will be date stamped and returned to the commenter.
	The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.  Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
	The FAA has determined that this regulation is an emergency regulation and that it is not considered to be major under Executive Order 12291.  It is impracticable for the agency to follow the procedures of Order 12291 with respect to this rule since the rule must be issued immediately to correct an unsafe condition in aircraft.  It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).  If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket.  A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39

	Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment 

	Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES

	1.  The authority citation for part 39 continues to read as follows:

	Authority:  49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

§39.13 - [AMENDED]

	2.  Section 39.13 is amended by adding the following new airworthiness directive:

93-11-11  AC, TEXTRON LYCOMING, AND RAJAY/ROTOMASTER:  Amendment 39-8584.  Docket 93-ANE-16.

	Applicability:  AC, Textron Lycoming, and Rajay/Rotomaster-modified high pressure diaphragm fuel pumps, overhauled by Aero Accessories Inc. (AAI) between June 18, 1991, and November 24, 1992; AC model 41234, having AAI serial numbers (S/Ns) 91F006 through 92E050 and 92E052 through 92K008; AC model 40296, having AAI S/Ns 92B002 through 92I155; AC model 41812, having AAI S/N 91L142; Textron Lycoming model LW15473, having AAI S/Ns 91K049 through 92I151; Rajay/Rotomaster-modified model R00253-501, having AAI S/Ns 92D136 through 92J016; Rajay/Rotomaster modified model R00253-502, having AAI S/Ns 92D120 through 92H075; and Rajay/Rotomaster-modified model 103586-01, having AAI S/N 92J024; installed on but not limited to Textron Lycoming IO-320, LIO-320, IO-360, LIO-360, O-540-L3C5D, IO-540, TIO-540, and LTIO-540 piston engines; installed on but not limited to piston engine powered aircraft manufactured by Beechcraft, Bellanca, Cessna, Mooney, Piper, and Rockwell Commander (Models 112 and 114) aircraft; and
	AC, Textron Lycoming, and Rajay/Rotomaster-modified low pressure diaphragm fuel pumps, overhauled by AAI between November 1, 1991, and August 20, 1992; AC model numbers 40174, 40295, 40595, 41270, 41271, 41272, 41452, 41617, 75246, 75247; Textron Lycoming model numbers LW14282, LW15399, LW15472, LW16335, LW16775, LW16947; and Rajay/Rotomaster-modified models 103396-01, RJ4033, and R00253-2; having AAI S/Ns 91K073 through 91K125, all S/Ns beginning with prefixes 91L, 92A, 92B, 92C, 92D, 92E, 92F, 92G, and 92H001 through 92H146; installed on but not limited to Textron Lycoming model O-235, O-290, O-320, O-360, LO-360, LTO-360, and O-540 piston engines; installed on but not limited to piston engine powered aircraft manufactured by Beechcraft, Bellanca, Cessna, Mooney, and Piper.

	Compliance:  Required prior to further flight, unless accomplished previously.

	To prevent disruption of fuel flow to the engine, which can result in a loss of engine power, accomplish the following:
   (a)	Remove from service affected low pressure diaphragm fuel pumps and replace with a serviceable pump.
   (b)	For the purposes of paragraph (a) of this AD, a serviceable low pressure diaphragm fuel pump is either an AC, Textron Lycoming, or Rajay/Rotomaster-modified pump that has never been overhauled by AAI, or has an "S" stamped on the flange above the inlet port of the fuel pump to indicate previous compliance with priority letter AD 92-20-07.
   (c)	No further action is required for all affected low pressure diaphragm fuel pumps that have complied previously with priority letter AD 92-20-07.

NOTES:
   1.	The model number is located on the edge of the mounting flange.
   2.	The S/N is located on the "housing backbone" between the mounting flange and the round spring housing.
   3.	For further information, see Aero Accessories, Inc. Mandatory Service Bulletin No. 001, dated August 21, 1992.  Copies of this service bulletin may be obtained from Aero Accessories, Inc., 1240 Springwood Church Road, Gibsonville, NC 27249, telephone (919) 449-5054.

   (d)	Remove from service affected high pressure diaphragm fuel pumps and replace with a serviceable pump.
   (e)	For the purposes of paragraph (d) of this AD, a serviceable high pressure diaphragm fuel pump is either an AC, Textron Lycoming, or Rajay/Rotomaster-modified pump that has never been overhauled by AAI, or has an "S2" stamped on the flange above the inlet port of the fuel pump to indicate previous compliance with priority letter AD 93-05-21.
   (f)	All affected high pressure diaphragm fuel pumps must be replaced, regardless of compliance with priority letter AD 92-20-07.

NOTES:
   1.	The model number is located on the edge of the mounting flange.
   2.	The serial number is located on the "housing backbone" between the mounting flange and the round spring housing.
   3.	For further information, see Aero Accessories, Inc. Mandatory Service Bulletin No. 002, dated February 25, 1993.  Copies of this service bulletin may be obtained from Aero Accessories, Inc., 1240 Springwood Church Road, Gibsonville, NC 27249, telephone (919) 449-5054.

   (g)	An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Atlanta Aircraft Certification Office.  The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta Aircraft Certification Office.

	NOTE:  Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Atlanta Aircraft Certification Office.

   (h)	This amendment supersedes priority letter AD 93-05-21, issued March 17, 1993.
   (i)	This amendment becomes effective on June 21, 1993.

FOR FURTHER INFORMATION CONTACT:  Jerry Robinette, Aerospace Engineer, Propulsion Branch, Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate, 1669 Phoenix Parkway, Suite 210C, Atlanta, GA 30349; telephone (404) 991-3810; fax (404) 991-3606.

Manufacturer’s Service Information: See Appliance Index for PDF copies of the SBs.
Aero Accessories, Inc. Mandatory Service Bulletin No. 001
Aero Accessories, Inc. Mandatory Service Bulletin No. 002

Copies of this service bulletin may be obtained from Aero Accessories, Inc., 
1240 Springwood Church Road, Gibsonville, NC 27249, telephone (919) 449-5054.