Discussion
We have received a report of 18 instances of failed forward water drain/supply valves on Gulfstream Model GIV-X, GV, and GV-SP series airplanes. Investigation by the airplane manufacturer revealed that the water drain/supply valves can be damaged by attempted operation when they are frozen. We also received a report of seven instances of ice striking the wing-to-body fairings and engine nose cowls of several airplanes. Leakage from failed water drain/supply valves can allow the build-up of ice on the airplane, which could separate and strike the airplane structure aft of the failed valves; become ingested by a propulsion engine; or become a hazard to persons or property on the ground.
Relevant Service Information
We have reviewed the Gulfstream airplane flight manual (AFM) supplements and alert customer bulletins, including the Joint Aviation Authority (JAA) Gulfstream AFM revisions. We have identified these documents in the following tables.
The Gulfstream AFM supplements describe procedures for revising the Normal Procedures section of the AFMs of the affected airplanes to specify a functional check of forward water drain/supply valves, and corrective actions if necessary. Corrective actions include purging, deactivating, and securing the galley and lavatory sinks, or the entire water system, as applicable, and placarding those systems "Inoperative'' or "Do Not Use.'' The AFM supplements are identified as follows:
Gulfstream AFM Supplements
Airplane Model
AFM Supplement
Date
G350-2007-01
April 12, 2007
GIV-X
G450-2007-02
April 12, 2007
GV
GV-2007-04
April 12, 2007
G500-2007-03
April 12, 2007
GV-SP
G550-2007-05
April 12, 2007
The alert customer bulletins identified in the following table describe procedures for doing repetitive functional checks of the forward water drain/supply valves for leakage; inspecting to determine whether the water supply valve has part number(P/N) 4E4151-1 or the water drain valve has P/N 4E4151-3; and replacing any water supply valve having P/N 4E4151-1 with a new, improved valve having P/N 4E4491- 1, or any water drain valve having P/N 4E4151-3 with a new, improved valve having P/N 4E4493-1. The alert customer bulletins also specify reporting compliance to the manufacturer.
Gulfstream Alert Customer Bulletins
Airplane Model
Alert Customer Bulletin
Date
G350 Number 5
April 11, 2007
GIV-X
G450 Number 5
April 11, 2007
GV
GV Number 26
April 11, 2007
G500 Number 7
April 11, 2007
GV-SP
G550 Number 7
April 11, 2007
The information contained in the JAA AFM revisions identified in the following table is considered acceptable by the European Aviation Safety Agency (EASA) for airplanes operated under and in accordance with the JAA and EASA regulations, supervision, and oversight:
JAA Gulfstream AFM Revisions
Airplane Model
JAA AFM Revisions
Date
JAA-G350-2007-01
May 21, 2007
GIV-XJAA- G450-2007-01
May 21, 2007
GV
JAA-GV-2007-02
May 21, 2007
JAA-G500-2007-03
May 21, 2007
GV-SP
JAA-G550-2007-03
May 21, 2007
FAA's Determination and Requirements of This AD
The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design. For this reason, we are issuing this AD to prevent leakage from failed water drain/supply valves allowing the build-up of ice on the airplane, which could separate and strike the airplane structure aft of the failed valves; become ingested by a propulsion engine; or become a hazard to persons or property on the ground. This AD requires accomplishing the actions specified in the service information described previously, except as discussed under "Differences Between the AD and Service Information.''
Differences Between the AD and Service Information
The alert customer bulletins do not describe procedures to be followed if the part number of a water drain/supply valve ismissing or cannot be determined. However, this AD requires replacing any such valve with a new, improved valve having P/N 4E4491-1 or P/N 4E4493-1, as applicable.
Although the Accomplishment Instructions of the referenced alert customer bulletins describe procedures for submitting reports of compliance with the service bulletin, this AD does not require those actions.
Interim Action
We consider this AD interim action. We are currently considering requiring the optional terminating action (replacing the water drain/ supply valves) provided in this AD, which will terminate the required repetitive functional checks. However, the planned compliance time for the terminating action would allow enough time to provide notice and opportunity for prior public comment on the merits of the valve replacement.
Clarification of Terminology
This AD provides procedures for repetitive functional checks for proper operation of the forward water drain/supply valves, and corrective actions if necessary. We have determined that these functional checks and corrective actions may be properly performed by the cockpit flightcrew because the checks and actions do not require tools, precision measuring equipment, training, or pilot logbook endorsements, or the use of or reference to technical data.
FAA's Determination of the Effective Date
Since an unsafe condition exists that requires the immediate adoption of this AD, we have found that notice and opportunity for public comment before issuing this AD are impracticable, and that good cause exists to make this AD effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include "Docket No. FAA-2007- 28373; Directorate Identifier 2007-NM-110-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.
Examining the Docket
You may examine the AD docket on the Internet at http://dms.dot.gov , or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647- 5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
Regulatory Findings
We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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.
For the reasons discussed above, I certify that the regulation:
1. Is not a "significant regulatory action'' under Executive Order 12866;
2. Is not a "significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities underthe criteria of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):