Federal Register: August 17, 2005 (Volume 70, Number 158)
DOCID: FR Doc 05-16267
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
CFR Citation: 14 CFR Part 39
Docket ID: [Docket No. FAA-2005-21787; Directorate Identifier 2005-CE-34-AD]
RIN ID: RIN 2120-AA64
NOTICE: PROPOSED RULES
ACTION: Airworthiness directives:
DOCUMENT ACTION: Notice of proposed rulemaking (NPRM).
SUBJECT CATEGORY:
Airworthiness Directives; Shadin ADC-2000 Air Data Computers
DATES: We must receive any comments on this proposed AD by October 11, 2005.
DOCUMENT SUMMARY:
The FAA proposes to adopt a new airworthiness directive (AD) for certain Shadin ADC2000 air data computers (ADC) installed on airplanes. This proposed AD would require you to replace affected ADC 2000 units with a modified unit. This proposed AD results from reports that certain ADC2000 units display incorrect altitude information on the Electronic Flight Information System (EFIS) to the pilot. We are issuing this proposed AD to prevent ADC2000 units, part numbers (P/Ns) 962830A1S8, 962830A2S8, and 962830A3S8, configurations B, C, and D, from displaying incorrect altitude information. This could cause the flight crew to react to this incorrect flight information and possibly result in an unsafe operating condition.
SUMMARY:
Shadin,
SUPPLEMENTAL INFORMATION
Comments Invited
How do I comment on this proposed AD? We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include the docket number, ``FAA200521787; Directorate Identifier 2005CE34AD'' at the beginning of your comments. 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 proposed rulemaking. Using the search function of our docket Web site, anyone can find and read the comments received into 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.). This is docket number FAA200521787; Directorate Identifier 2005CE 34AD. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 1947778) or you may visit http://dms.dot.gov.
Are there any specific portions of this proposed AD I should pay attention to? We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.
Docket Information
Where can I go to view the docket information? You may view the AD docket that contains the proposal, any comments received, and any final disposition in person at the DMS Docket Offices between 9 a.m. and 5 p.m. (eastern standard time), Monday through Friday, except Federal holidays. The Docket Office (telephone 18006475227) is located on the plaza level of the Department of Transportation NASSIF Building at the street address stated in ADDRESSES. You may also view the AD docket on the Internet at http://dms.dot.gov. The comments will be available in the AD docket shortly after the DMS receives them.
Discussion
What events have caused this proposed AD? We have received reports that the pressure altitude output of certain Shadin ADC2000 air data computers (ADC) drift outside Technical Standard Order (TSO) tolerance.
Shadin ADC2000 units, part numbers (P/Ns) 962830A1S8, 962830A 2S8, and 962830A3S8, configurations B, C, and D (labeled with TSO C106 and TSOC44a), provide altitude information that is displayed on the Electronic Flight Information System (EFIS) to the pilot. The ADC/ EFIS combination is used to display primary altitude information to the pilot.
The maximum altitude error allowed by TSOC106 and TSOC44a is 25 feet at ground level. Shadin ADC2000 units, P/Ns 962830A1S8, 962830A2S8, and 962830A3S8, configurations B, C, and D, have shown errors from 100 to 8,000 feet from the correct altitude.
The errors are caused by the ADC2000 altitude measurement system. A pressure transducer in the ADC measures the altitude from the airplane static pressure system. The pressure transducer converts static pressure to an electrical signal.
We have determined that the electrical output from the pressure transducer in the affected ADCs changes over time resulting in the display of misleading altitude information to the pilot.
What is the potential impact if FAA took no action? If this situation occurs while the flight crew is making critical flight decisions, the display of incorrect altitude information could cause the flight crew to react to this incorrect flight information and possibly result in an unsafe operating condition.
Is there service information that applies to this subject? Shadin has issued Service Bulletin SB2805002, Rev C, dated June 29, 2005.
What are the provisions of this service information? The service bulletin includes procedures for doing preflight checks to ensure ADC/ EFIS altimetry accuracy and specifies having ADC2000, P/Ns 962830A1 S8, 962830A2S8, and 962830A3S8, configurations B, C, and D, upgraded to new P/Ns 962831A1S8, 962831A2S8, and 962831A3S8. FAA's Determination and Requirements of this Proposed AD
What has FAA decided? We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on these ADCs that are installed on type design airplanes.
What would this proposed AD require? This proposed AD would require you to incorporate the actions in the previouslyreferenced service bulletin.
How does the revision to 14 CFR part 39 affect this proposed AD? On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 457 units installed on airplanes in the U.S. registry.
What would be the cost impact of this proposed AD on owners/
operators of the affected airplanes? We estimate the following costs to do this proposed modification:
[[Page 48335]]
Total cost
Labor cost Parts cost per unit
2 work hours x $65 per hour = Not applicable.......... $130. $130.
Shadin will reimburse the owner/operators for labor to remove and replace the ADC and shipping costs to Shadin Repair Facility to the extent specified in the service bulletin.
Authority for This Rulemaking
What authority does FAA have for issuing this rulemaking action? 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 AD. Regulatory Findings
Would this proposed AD impact various entities? We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.
Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed
FOR FURTHER INFORMATION CONTACT
Jeffrey Kuen, Aerospace Engineer, Chicago Aircraft Certification Office (ACO), FAA, 2300 East Devon Avenue, Room 107, Des Plaines, Illinois 60018; telephone: (847) 294 7125; facsimile: (847) 2947834; email address: jeffrey.kuen@faa.gov.