Source: https://www.federalregister.gov/documents/2006/11/15/E6-19227/airworthiness-directives-boeing-model-737-airplanes
Timestamp: 2017-11-24 15:02:30
Document Index: 206136739

Matched Legal Cases: ['art 1', 'art 2', 'art 1', 'art 2', 'art 1', 'art 2', '§\u200939', 'art 2', 'art 2', 'art 2', 'art 1', 'art 1', 'art 1']

We must receive comments on this proposed AD by January 2, 2007.
71 FR 66474
66474-66480 (7 pages)
E6-19227
For Certain Airplanes: Tests, Suspension of Certain Master Minimum Equipment Item, Replacements, Inspection, and Corrective Actions
https://www.federalregister.gov/d/E6-19227 https://www.federalregister.gov/d/E6-19227
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Boeing Model 737 airplanes. The existing AD currently requires installation of a new rudder control system and changes to the adjacent systems to accommodate that new rudder control system. For certain airplanes, this proposed AD would add, among other actions, repetitive tests of the force fight monitor of the main rudder power control unit (PCU), repetitive tests of the standby hydraulic actuation system, and corrective action; as applicable. For those airplanes, this proposed AD also would add, among other actions, replacement of both input control rods of the main rudder PCU and the input control rod of the standby rudder PCU with new input control rods, as applicable, which would end the repetitive tests. For certain other airplanes, this proposed AD would add installation of an enhanced rudder control system in accordance with new service information. This proposed AD results from a report of a fractured rod end on an input control rod of the main rudder PCU. We are proposing this AD to prevent failure of one of the two input control rods of main rudder PCU, which, under certain conditions, could result in reduced controllability of the airplane; and to prevent failure of any combination of two input control rods of the main rudder PCU and/or standby rudder PCU, which could result in loss of control of the airplane. We are also proposing this AD to prevent an uncommanded rudder hardover event and consequent loss of control of the airplane due to inherent failure modes, including single-jam modes, and certain latent failures or jams combined with a second failure or jam.
Start Printed Page 66475
We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “Docket No. FAA-2006-26323; Directorate Identifier 2006-NM-150-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.
On October 30, 2002, we issued AD 2002-20-07 R1, amendment 39-12940 (67 FR 67518, November 6, 2002), for all Boeing Model 737 airplanes. That AD requires installation of a new rudder control system and changes to the adjacent systems to accommodate that new rudder control system. That AD resulted from FAA determinations that the existing system design architecture is unsafe. We issued that AD to prevent an uncommanded rudder hardover event and consequent loss of control of the airplane due to inherent failure modes, including single-jam modes, and certain latent failures or jams combined with a second failure or jam.
Since the issuance of AD 2002-20-07 R1, we have received a report of a fractured rod end on one of the two input control rods of the main rudder power control unit (PCU) on a Model 737-800 series airplane. This condition was discovered during heavy maintenance. The rod end had not separated from the input control rod and was retained by the sealant used during the assembly of the input control rod. The condition was discovered because the aft rod end of the lower input control rod appeared loose. If the rod end does not separate from the input control rod, there is no indication of fracture and it will not likely be detected during normal flight operation.
If a rod end separates from an input control rod of the main rudder PCU, the input to the A and B sides of the main rudder PCU (the main rudder PCU is a dual tandem actuator) will not match. This condition will cause a force fight between the A and B sides in the main rudder PCU, which will activate the force fight monitor, activate the standby hydraulic system, and illuminate the STBY RUD ON light on the P5-3 panel. Dispatch is not allowed with the STBY RUD ON light illuminated.
The incident airplane had been modified to comply with the requirements of AD 2002-20-07 R1. We previously approved the service bulletins in the table titled “Previously Approved Service Bulletins” as an alternative method of compliance (AMOC) for the requirements of AD 2002-20-07 R1. These service bulletins include procedures to replace both input control rods of the main rudder PCU and the input control rod of the standby rudder PCU (for certain airplanes) with new input control rod(s) having part number (P/N) 251A3495-1, which, we have since determined, had an improper heat treatment during manufacture.
Previously Approved Service Bulletins
737-100, -200, and -200C series airplanes 737-27-1252, Revision 2, dated December 9, 2004; Revision 1, dated September 25, 2003; and Original Issue, dated June 26, 2003.
737-300, -400, and -500 series airplanes 737-27-1255, Revision 2, dated July 22, 2004; Revision 1, dated June 26, 2003; and Original Issue, dated May 1, 2003.
737-600, -700, -700C, -800, and -900 series airplanes 737-27-1253, Revision 2, dated October 7, 2004; Revision 1, dated March 27, 2003; and Original Issue, dated January 2, 2003.
Failure of one of the two input control rods of the main rudder PCU under certain conditions, if not corrected, could result in reduced controllability of the airplane. Failure of any combination of two input control rods of the main rudder PCU and/or standby rudder PCU, if not corrected, could result in loss of control of the airplane. Start Printed Page 66476
We have reviewed the service bulletins in the table titled “Service Bulletins for Repetitive Tests and Other Actions.” The service bulletins specify an initial compliance time for doing the initial test of the standby system of within 60 days after the date of the service bulletin, and a repetitive interval of 500 flight hours. The service bulletins also specify an initial compliance time for doing the initial test of the force fight monitor of within 90 days or 6,000 flight hours after the date of the service bulletin, depending on the airplane configuration, and a repetitive interval of 6,000 flight hours. For airplanes identified as Groups 1 and 2, Configuration 2, in Boeing Alert Service Bulletin 737-27A1281, dated June 14, 2006; and airplanes identified as Group 1, Configuration 2, in Boeing Alert Service Bulletin 737-27A1280, dated May 25, 2006; no work is necessary in accordance with these service bulletins. The improperly heat-treated control rods were not installed on those airplanes.
Service Bulletins for Repetitive Tests and Other Actions
Describes procedures for doing—
737-600, -700, -700C, -800 and -900 series airplanes 737-27A1280, dated May 25, 2005 The “Rudder Main Power Control Unit Force Fight Monitor Test,” the “Operational Test of the Standby Hydraulic Actuation System,” and applicable corrective action if necessary.
737-100, -200, -200C, -300, -400, and -500 series airplanes 737-27A1281, dated June 14, 2006 The “Rudder Main Power Control Unit Force Fight Test,” the “Standby Rudder Actuator Shutoff Valve Test,” and applicable corrective action if necessary.
We also have reviewed the service bulletins in the table titled, “Service Bulletins for Installation of an RSEP and Replacement of Input control rods.” Boeing uses the acronym RSEP for the “Rudder System Enhancement Program.” \
Service Bulletins for Installation of an RSEP and Replacement of Input Control Rods
Which ends the repetitive tests specified in Boeing Service Bulletin—
737-100, -200, and -200C series airplanes Service Bulletin 737-27-1252, Revision 3, dated May 12, 2006 Installing an RSEP (Part 1), and replacing both input control rods of the main rudder PCU with new input control rods (Part 2) 737-27A1281, dated June 14, 2006.
737-300, -400, and -500 series airplanes Service Bulletin 737-27-1255, Revision 3, dated May 10, 2006 Installing an RSEP (Part 1), and replacing both input control rods of the main rudder PCU with new input control rods (Part 2) 737-27A1281, dated June 14, 2006.
737-600, -700, -700C, -800, and -900 series airplanes Service Bulletin 737-27-1253, Revision 3, dated May 12, 2006 Installing an RSEP (Part 1); and replacing both input control rods of the main rudder PCU with new input control rods, inspecting the control rod of the standby rudder PCU to determine if part number (P/N) 251A3495-1 is installed, and doing corrective action if necessary (Part 2) (i.e., replacing any improperly heat-treated input control rod with a new input control rod) 737-27A1280, dated May 25, 2005.
Alert Service Bulletin 737-27A1279, dated June 20, 2006 Replacing both input control rods of the main rudder PCU and the input control rod of the standby rudder PCU with new input control rod(s) 737-27A1280, dated May 25, 2005.
Boeing Alert Service Bulletins 737-27-1252, 737-27-1253, and 737-27-1255, all Revision 3, also specify prior or concurrent accomplishment of the actions described in the table titled, “Prior/Concurrent Service Information.”
Prior/Concurrent Service Information
Prior to or concurrently with the actions in Boeing Alert Service Bulletin—
Do this action—
737-27-1252, Revision 3, dated May 12, 2006 Remove the rudder position sensor of the automatic flight control system Boeing Service Bulletin 737-22-1042, Revision 1, dated April 5, 1985.
Replace the rudder feel and centering assembly with a new all-mechanical unit Boeing Service Bulletin 737-27-1026, dated January 15, 1971.
Install the rudder pressure reducer and yaw damper coupler Boeing Service Bulletin 737-27A1206, Revision 3, dated December 14, 2000.
Install provisional wires for rudder system enhancement Boeing Service Bulletin 737-27-1246, Revision 1, dated February 21, 2002.
Replace the P5-3 panel with a new panel Boeing Service Bulletin 737-27-1263, Revision 1, dated September 25, 2003.
Start Printed Page 66477
Replace the input lever for the auxiliary rudder power control package with a new input lever Smiths Aerospace Service Bulletin 1150-27-05A, dated August 28, 2003.
737-27-1253, Revision 3, dated May 12, 2006 Install provisional wires for rudder system enhancement Boeing Service Bulletin 737-27-1247, Revision 1, dated July 25, 2002.
Replace the P5-3 panel with a new panel Boeing Service Bulletin 737-27-1262, dated December 19, 2002.
Relocate the wire bundle routing in the vertical stabilizer Boeing Alert Service Bulletin 737-27A1239, dated January 11, 2001.
737-27-1255, Revision 3, dated May 10, 2006 Install provisional wires for rudder system enhancement Boeing Service Bulletin 737-27-1246, Revision 1, dated February 21, 2002.
Replace the P5-3 panel with a new panel Boeing Service Bulletin 737-27-1265, Revision 1, dated April 3, 2003.
Install a new yaw damper coupler Boeing Service Bulletin 737-27A1206, Revision 3, dated December 14, 2000.
Inspect and rework the trailing edge beam on the vertical fin Boeing Service Bulletin 737-55-1052, Revision 1, dated August 5, 2004.
We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 2002-20-07 R1 and would retain the requirements of the existing AD. This proposed AD would also require accomplishing the actions specified in the applicable service information described previously. For certain airplanes, this proposed AD also would require suspending a certain Master Minimum Equipment Item, until the improperly heat-treated input control rods are replaced.
This proposed AD would retain all requirements of AD 2002-20-07 R1. Since AD 2002-20-07 R1 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:
Requirement in AD 2002-20-07 R1
paragraph (b) paragraph (b) (with new title).
There are about 6,412 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 1,678 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD. The average labor rate is $80 per work hour.
Installation of rudder control system (required by AD 2002-20-07 R1, and retained in this NPRM) 700 $140,000 $196,000 $328,888,000.
Repetitive tests, per test cycle (new action proposed by this NPRM) 2 None $160, per test cycle Up to $268,480 depending on the configuration of the airplanes.
Replacement of the input control rods (new action proposed by this NPRM) (ends repetitive tests) 5 to 7 The manufacturer states that it will supply required parts to the operators at no cost $400 to $560 Up to $939,680, depending the configuration of the airplanes.
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 Start Printed Page 66478that is likely to exist or develop on products identified in this rulemaking action.
2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-12940 (67 FR 67518, November 6, 2002) and adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2006-26323; Directorate Identifier 2006-NM-150-AD.
(c) This AD applies to all Boeing Model 737-100, -200, -200C, -300, -400, -500, -600, -700,-700C, -800 and -900 series airplanes, certificated in any category.
(d) This AD results from a report of a fractured rod end on an input control rod of the main rudder power control unit (PCU). We are issuing this AD to prevent failure of one of the two input control rods of the main rudder PCU, which, under certain conditions, could result in reduced controllability of the airplane; and to prevent failure of any combination of two input control rods of the main rudder PCU and/or standby rudder PCU, which could result in loss of control of the airplane. We are also issuing this AD to prevent an uncommanded rudder hardover event and consequent loss of control of the airplane due to inherent failure modes, including single-jam modes, and certain latent failures or jams combined with a second failure or jam.
(1) Install a new rudder control system that includes new components such as an aft torque tube, hydraulic actuators, and associated input control rods, and additional wiring throughout the airplane to support failure annunciation of the rudder control system in the flight deck. The system also must incorporate two separate inputs, each with an override mechanism, to two separate servo valves on the main rudder PCU; and an input to the standby PCU that also will include an override mechanism.
(g) For airplanes on which the actions required by paragraph (f) of this AD have been done before the effective date of this AD: Do the actions in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, as applicable.
(1) At the applicable times listed in paragraph 1.E., “Compliance,” of the applicable service bulletin specified in Table 2 of this AD; except, where the service bulletin specifies a compliance time from the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD: Do the tests specified in Table 2 of this AD, until the installation required by paragraph (g)(3) of this AD has been done in accordance with the applicable service bulletin in Table 3 of this AD. Do all applicable corrective actions specified in Table 2 of this AD before further flight.
Table 2.—Repetitive Tests
(i) 737-100, -200, and -200C series airplanes Group 1, Configuration 1 in the service bulletin The “Rudder Main Power Control Unit Force Fight Test,” the “Standby Rudder Actuator Shutoff Valve Test,” and any applicable corrective action Boeing Alert Service Bulletin 737-27A1281, dated June 14, 2006.
(ii) 737-300, -400, and -500 series airplanes Group 2, Configuration 1 in the service bulletin The “Rudder Main Power Control Unit Force Fight Test,” the “Standby Rudder Actuator Shutoff Valve Test,” and any applicable corrective action Boeing Alert Service Bulletin 737-27A1281, dated June 14, 2006.
(iii) 737-600, -700, -700C, -800, and -900 series airplanes Group 1, Configuration 1 and Group 2, Configurations 1 and 2 in the service bulletin The “Rudder Main Power Control Unit Force Fight Monitor Test,” the “Operational Test of the Standby Hydraulic Actuation System,” and any applicable corrective action Boeing Alert Service Bulletin 737-27A1280, dated May 25, 2005.
(2) As of the effective date of this AD, do not use the Master Minimum Equipment Item 27-21, “STBY RUD ON light,” until the actions required by paragraph (g)(3) of this AD are done.
(3) Within 24 months after the effective date of this AD, do the replacement(s) and inspection, as applicable, specified in Table 3 of this AD. Do all applicable corrective actions specified in Table 3 of this AD before further flight. Doing the applicable action(s) ends the requirements of paragraphs (g)(1) and (g)(2) of this AD.
Table 3.—Replacement of Input Control Rods, Inspection, and Corrective Action, as Applicable
(i) 737-100, -200, and -200C series airplanes Groups 1 through 9, Configuration 3 in the service bulletin Replace both input control rods of the main rudder PCU with new input control rods Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 737-27-1252, Revision 3, dated May 12, 2006.
(ii) 737-300, -400, and -500 series airplanes Groups 1 through 19, Configuration 3 in the service bulletin Replace both input control rods of the main rudder PCU with new input control rods Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 737-27-1255, Revision 3, dated May 10, 2006.
(iii) 737-600, -700, -700C, -800, and -900 series airplanes Groups 1 through 20, Configuration 3 in the service bulletin Replace both input control rods of the main rudder PCU with new input control rods, inspect the input control rod of the standby rudder PCU to determine if part number (P/N) 251A3495-1 is installed, and any corrective action Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 737-27-1253, Revision 3, dated May 12, 2006.
(iv) 737-600, -700, -700C, -800, and -900 series airplanes Group 1 in the service bulletin Replace both input control rods of the main rudder PCU and the input control rod of the standby rudder PCU with a new input control rod(s) The Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1279, dated June 20, 2006.
(h) For airplanes on which the actions required by paragraph (f) of this AD have not been done before the effective date of this AD: As of the effective date of this AD, use the applicable service bulletin specified in Table 4 of this AD to do the actions required by paragraph (f) of this AD at the time specified in that paragraph.
Table 4.—Service Bulletins for Installation of New Rudder Control System
(1) 737-100, -200, and -200C series airplanes Groups 1 through 9, Configurations 1 and 2 in the service bulletin Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 737-27-1252, Revision 3, dated May 12, 2006.
(2) 737-300, -400, and -500 series airplanes Groups 1 through 19, Configurations 1 and 2 in the service bulletin Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 737-27-1255, Revision 3, dated May 10, 2006.
(3) 737-600, -700, -700C, -800, and -900 series airplanes Groups 1 through 20, Configurations 1 and 2 in the service bulletin Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 737-27-1253, Revision 3, dated May 12, 2006.
(i) Before or concurrently with the requirements of paragraph (h) of this AD, do the actions in Table 5 of this AD. Start Printed Page 66480
Table 5.—Before/Concurrent Requirements
(iv) Install provisional wires for rudder system enhancement Boeing Service Bulletin 737-27-1246, Revision 1, dated February 21, 2002.
(vi) Replace the input lever for the auxiliary rudder power control package with a new input lever Smiths Aerospace Service Bulletin 1150-27-05A, dated August 28, 2003.
(2) Paragraph (h)(2) of this AD (i) Install provisional wires for rudder system enhancement Boeing Service Bulletin 737-27-1246, Revision 1, dated February 21, 2002.
(v) Replace the input lever for the auxiliary rudder power control package with a new input lever Smiths Aerospace Service Bulletin 1150-27-05A, dated August 28, 2003.
[FR Doc. E6-19227 Filed 11-14-06; 8:45 am]