December 15, 20 10
U . S. Department of Transportation Docket Operations West Building Ground Floor, Room W12-140 1200 New Jersey Avenue , SE. Washington DC. 20590 

# Continental Airlines PMI 0111 ,'80x 4623 HQJOA Ho ',}fl TX 77210-4623 COI'1!mefllal :om

Subject Request for Exemption to Sections of 14 C FR Parts 121. and 121.344(f): Continental Airlines, Inc. would like to petition the Federal Aviation Administration for a time limited exemption of 18 months from December 6, 2010 to section 14 CFR part 121 , and 121 .344(f) to continue operation using a flight data recorder system that does not comply with those sampling requirements . Refe rence to the regulatory relief sought: Continental Airlines requests a time limited exemption to recording the flight data recorder parameter "All cockpit flight control input forces (control wheel , control column, rudder pedal).w for the rudder pedal input forces parameter as required by 14 CFR 121 .344 (f), to permit operation of some 737-824 and 737-924ER airplanes in FAR 121 service. 14 CFR Part 121.344 (f) states U(fJ For all turbine-engine-powered tr ansport category airplanes that are manufactured afterAugust 19, 2002.(1) The parameters listed in paragraph ( a) (1) through (88) ofthis section must be recorded within the ranges, accuracies, resolutions, and recording intervals specified in Appendix M ofthi s part- . 14 CFR Part 121 Appendix M (Note 18) states " For all aircraft manufactured on or after December 6, 2010, the seconds persampling intervalis 0.125. Each input must be recorded at this rate. Alternatelysampling (nputs (interleaving) to meet this sampling interval is prohibitedw • Extent of Relief This exemption, specifically, would allow for the continued domestic and international operations of the following Continental Airlines operated 8737-824 and 8737-924ER series aircraft (See Table 1) for 18 months from December 6, 2010 without a speCific 14 CFR. Part 121 .344 (f). and 121 Appendix (M) mandated Digital Fl ight Data Acquisition Unit (DFDAU) recorded parameter (See Table 2) :

A STAR ALLIANCE MEMBER .,. : :Continental Airlines - 737NG Exempti()(l Request Table 1 (Ai rcraft Applicable to th is Exemption) Make 

### f Model 

### Serial 

### # Line 

### # Registration 

### # Boeing 

### f 

### 737-924 3 1 655 3393 N38443 Boeing 

### f 

### 737-924 31643 3417 N36444 Boeing 

### f 

### 737-924 40000 3615 N73445 Boeing 

### f 737-824 31663 3464 N76528 Boeing 

### f 

### 737-824 31652 3490 N76529 Boeing 

### f 

### 737-824 39998 3521 N77530 Boeing 

### f 

### 737-824 39999 3549 N77531 Tabl e 2 (System Signals recording 7 samples in lieu of 8 by the DFDAU) 121 .344 (I) 

### Parameter# 88



### Reason for relief Appendix M 

### Requirement Input to DFDAU All Cockpit flight contr ol Rudder Pedal Input Forces Input forces (control wheel, control column, rudder pedal)

This exemption is necessitated by the Aircraft Manufacturer (B oeing) and the Digital Flight Data Acquisition Unit (D FDAU) syst em 

### I software supplier (Teledyne) need to develop, validate, and integrate the enhanced system software into the aircraft type design. This enhanced software will provide for the DFDAU recording of all regulatory required parameters and allow Continental Airlines time to install the software without significantly affecting flight operations. Backgro und Summary: A 737NG Flight Data Recorder System (FORS) anomaly was discovered during additional Boeing testing of the system. The FDRS configuration included a Teledyne Digital Flight Data Acquisition Unit (DFDAU) with the 737-7 data frame enabled. The data frame is a 512 words per second data frame that was certified in April 2010 

### to meet the latest FAA regu lations (§ 

### 121 .344 (f) 

### Appendix M), which are effective Dec 6,20 10. The following describes the anomaly and discusses Boeing's plan to correct the discrepancy. Discussion: After discovery of the Left Elevator Position parameter anomaly in October 2010, Boeing continued analysis of Flight Test data from a number of airplanes delivering with the Teledyne Controls DFDAU using the 737-7 data frame. Through that analysis, and confirmed by Teledyne, it was determined that the Rudder Pedal For ce parameter exhibits the same anomaly discussed in exemption approval 10172 

### dated December 9,2010. Per FAA regulations (§ 121.344 

### (I) Appendix M (parameter group 88), as of Dec 6 , 2010 

### the FDRS must record control wheel, control column and rudder pedal input forces at 8 samples per second. Page 2 of 5Continental Airlines - 737NG Exemption Request FOR data analysis showed that at times, 1 of the 8 samples of rudder pedal force data, in 

### a given second, could be stale (a previous sample) . The anomalous rudder pedal forces data is usually present only once every 5 seconds (i.e . once every 5 seconds there are only 7 valid samples and one invalid sample in a one second acquisition period (Sub frame) . It is possible to deduce a corrected rudder pedal force sample from linear interpolation between correct rudder pedal force samples around the anomaly. In summary, this anomaly can be addressed in ground processing of the data . The root cause of this anomaly is found in a DFOAU software acquisition timing error. Periodically, in a given parameter acquisition cycle , the DFDAU is requesting the acquisition of more parameter data than it has time to complete in that acquisition cycle . Because parameter acquisition does not have time to complete, the previous valid sample recorded one second earlier is used in the recording rather than the desired current sample. The DFOAU software is software loadable and Teledyne has informed Boeing that this anomaly can be fixed with a minor software revision resulting in new software part numbers . Plan to Correct Anomaly: Boeing has verbally notified the FAA and is in the process of filing a revised "Report of Noncompliance with Part 25 Airworthiness Regulations" with the FAA stating that the anomaly does not represent a safety issue for continued operation Boeing has a signed contract in-work with Teledyne and plans to certify the new DFOAU software in approximately 5-6 months . The date of certification is contingent on what is found during testing , which may cause the schedule to move either left or the right. In any case , Boeing is actively working to accelerate the certification of corrected software. Public Interest The granting of this exemption would be in the public interest by allowing Continental Airlines to continue providing service to domestic and international destinations utilizing the B737-824 and B737-924ER series aircraft listed in Table 1 . Failure to grant this exemption would require Continental Airlines to cancel flights and disrupt schedules causing significant financial loss as well as impose inconvenience and potential lost-time cost to the traveling public. Affect on the Level of Safety The fact that the Digital Flight Data Recorder (OFOR) system is recording 7 samples per second in lieu of the 8 samples per second of the Rudder Pedal Force Parameter does not have an adverse affect on the normal or irregular operation of the aircraft. It is possible to deduce corrected Rudder Pedal Force using linear interpolation between correct rudder pedal force samples around the anomaly. In summary , this anomaly can be addressed in ground processing of the data . The manufacturer of the aircraft (Boeing )

Page 3 of 5Continental Ail1ioes - 737NG Exemption Request has reviewed this exemption and has determined ''the issue is not considered to be a risk to current and future operation ofthe airpfane. " Summary for the Federal Register Continental Airlines requests relief from the requirement for publication of the summary in the Federal Register due to delaying the action on the petition would adversely affect operations and the traveling public. This petition for exemption has been filed as soon as the need for a petition was discovered . If a summary for the Federal Register is required for this request, Continental Airlines provides the following : Continental Airlines is requesting an exemption from 14 CFR Part 121.344(0 to allow for the continued operation of 8737-824 and B737-924ER series aircraft in domestic and international revenue service without the installed Digital Flight Data Acquisition Unit (DFDAU) recording all 8 samples of the rudder input forces data. This exemption shall allow the Aircraft Manufacturer (Boeing) and the DFDAU System Software Provider (Teledyne) time to develop, validate, and certify the software to correct the DFDAU anomaly and allow Continental Airlines time to install the software with minimal interruption to flight schedu ling.

Additional Information 80eing has verbally notified the FAA and is in the process of filing a "Report of Noncompliance with Part 25 Airworthiness Regulations" with the FAA stating that the anomaly does not represent a safety issue for continued operation. Continental Airlines requests this petition for Exemption be expedited due to the requirements of 14 CFR Part 121 Appendix M (Note 18) are due December 6,2010.
Use of the Exemption outside the United States Continental Airlines would like to utilize the privileges of this exemption outside the United States. The primary scheduled operations for this model aircraft in Continental Airlines fleet includes international operations primarily in Canada , Mexico, Central America and the Caribbean Islands . Your consideration of the foregoing and timely approval of this request is appreciated. If you have any questions regarding this request, please feel free to contact this office.

Page 4 of 5Contillental Airlines - 737NG Exemption ReQuest

Rodney Luetzen Sr. Director Re liability and Quality Assurance On behalf of: Continental Airlines, Inc. Air Carrier Certificate CALA 014A 1600 Smith Street Houston, Texas 77002 Phone:713-324-9244 Fax: 7t3-324-169t Email : rodney.luetzen@coai r.com
cc: Federal Aviation Administration CALA Certificate Management Offi ce 2625 Bay Area Blvd. Suite 400 Houston , Texas 77058 The Boeing Company Brian Predmore - AC and Electrical Systems Group brian.k.predmore@boeing .com Ron Lockhart - OPERATIONAL SFTY & REGULATORY ronald .i.lockhart2@boeing .com Paul Sesny - OPERATIONAL SFTY & REGULATORY PauIASesny@boeing .com

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