02-6629. Airworthiness Directives; Rockwell Collins, Inc. ADC-85, ADC-85A, ADC-850D, and ADC-850F Air Data Computers

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); Reopening of the comment period.

SUMMARY:

This document proposes to revise an earlier proposed airworthiness directive (AD) that would apply to certain Rockwell Collins, Inc. (Rockwell) ADC-85, ADC-85A, ADC-850C, and ADC-850F air data computers that are installed on airplanes. The earlier NPRM would have required you to replace any affected air data computer (ADC) with one that has a reprogrammed and tested central processing unit (CPU) circuit card and circuit card assemblies. The earlier NPRM resulted from a flight test that showed that these ADCs could display an unwarranted ADC flag in response to the airplane's “Normal/Alternate Air” static source selection capability. Revised service information revealed the need to change the applicability of the affected ADC units that are installed on airplanes. In addition, evaluation of the public comments on the NPRM reveals the need to change the number and models of airplanes that could have the affected ADC units installed. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these additional actions.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before May 17, 2002.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-14-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays. You may also send comments electronically to the following address: [e-mail]. Comments sent electronically must contain “Docket No. 2000-CE-76-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII text.

You may get service information that applies to this proposed AD from Rockwell Collins, Business and Regional Systems, 400 Collins Road Northeast,Cedar Rapids, Iowa 52498; telephone: [phone]; facsimile: [phone]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Roger A. Souter, FAA, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Rm 100, Wichita, Kansas 67209; telephone: [phone]; facsimile: [phone]; e-mail address: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This Proposed AD?

The FAA invites comments on this proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date. We may amend this proposed rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of this proposed AD action and determining whether we need to take additional rulemaking action.

Are There Any Specific Portions of This Proposed AD I Should Pay Attention to?

The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of this proposed rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each contact we have with the public that concerns the substantive parts of this proposed AD.

How Can I Be Sure FAA Receives My Comment?

If you want FAA to acknowledge the receipt of your mailed comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2000-CE-14-AD.” We will date stamp and mail the postcard back to you.

Discussion

What Events Have Caused This Proposed AD?

The air data computer (ADC), as part of its monitoring process, tests for errant sensor behavior such as unreasonable jumps in altitude and unreasonably high vertical speed. When the ADC detects an errant sensor behavior, the ADC displays a flag for 5.5 seconds plus the time it takes for the sensor to settle within the limits for another 5.5-second period. This results in a minimum ADC flag display of 11 seconds.

Testing of certain Rockwell Collins ADCs reveals the ADC could display unwarranted flags on aircraft where you can select the “Normal/Alternate Air” static source. When there is a significant difference between normal and alternate/revisionary static air sources, you can exceed the ADC monitor thresholds and the ADC would display flags.

If the flight crew used the undesirable ADC flag displays to deselect the alternate static air source before the initial 11-second display period, a valid air source may have been deselected. Confusion could result when the previously unflagged normal static air source is reselected. This may also result in the ADC displaying a flag for the first 11 seconds. The affected ADCs include:

Unit	Part No.	Applicable to serial No.
ADC-85 (Incorporating Rockwell Collins Service Bulletin No. 58)	622-8051-002 622-8051-003	All units.
ADC-85A (Incorporating Rockwell Collins Service Bulletin No. 58)	822-0370-113 822-0370-123 822-0370-139 822-0370-404 822-0370-408	All units.
ADC-850D (Incorporating Rockwell Collins Service Bulletin No. 58)	822-0389-133	All up to and including 3DGW (except for 1P6D, 22RC-22RF, and 23WK-3DGP).
ADC-850F	822-1036-406 822-1036-418	All Units.

What Are the Consequences If the Condition Is Not Corrected?

If these situations were to occur while the flight crew were making critical flight decisions, this unwarranted ADC flag could distract the crew, and the lack of attention to the critical actions could result in an unsafe operating condition.

Is There Service Information That Applies to This Subject?

Rockwell has issued Service Bulletin No. 62 (ADC-85/85A/850C/850D/850E/850F-34-62), Revision 2, dated March 7, 2000, and Service Bulletin No. 62 (ADC-85/85A/850C/850F-34-62), dated October 25, 1999. Service Bulletin 62, Revision 2, reflects the addition of ADC-850D to the list of affected units and the removal of ADC-850C from the list of affected units.

What Are the Provisions of This Service Information?

These service bulletins contain procedures for replacing or reprogramming applicable parts or circuit card assemblies on central processing unit (CPU) circuit cards in the ADC and testing the modified ADC.

Has FAA Taken Any Action to This Point?

We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Rockwell Collins, Inc. (Rockwell) ADC-85, ADC-85A, ADC-850C, and ADC-850F air data computers that are installed on airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 2, 2000 (65 FR 58678). The NPRM proposed to require you to:

—Remove the ADC from the airplane;

—Replace or reprogram applicable parts or Circuit Card Assemblies on the CPU Circuit Card;

—Test the modified ADC; and

—Install the modified ADC in the airplane.

You would have to accomplish the proposed actions in accordance with Rockwell Service Bulletin No. 62 (ADC-85/85A/850C/850F-34-62), dated October 25, 1999.

Was the Public Invited To Comment?

The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:

Comment Issue No. 1: Remove Dassault Aviation Model F2000 From the Applicable Airplane Model List

What Is the Commenter's Concern?

A commenter states that, even though fitted with the subject ADC, the Dassault Aviation Model F2000 airplane is not designed with the ability to use alternate static sources.

What Is FAA's Response to the Concern?

We concur that the airplane is not designed with the ability to use alternate static sources. Therefore, we are removing the Dassault Aviation Model F2000 from the applicable airplane model list.

Comment Issue No. 2: Modify the Estimate of the Number of Airplanes Affected on the U.S. Registry

What Is the Commenter's Concern?

A commenter states that more aircraft are affected than the 245 listed in the NPRM. The commenter notes that the ADC is installed in additional aircraft and is installed on at least 329 airplanes.

What Is FAA's Response to the Concern?

The number of airplanes affected by this AD could exceed 245. We have no way of determining the exact number that have the affected ADCs installed. Our best estimate in the NPRM was 245 airplanes. Further research indicates that at least 329 airplanes could have the ADC installed. Therefore, we will change the cost impact to represent an estimate of 329 airplanes instead of 245 airplanes.

Comment Issue No. 3: Modify the List of Applicable Raytheon Airplanes

What Is the Commenter's Concern?

A commenter states that the list of affected airplanes is incorrect for Raytheon airplane models. The list incorrectly identifies two of the Raytheon airplane models as 250 and 350. The commenter states that these are marketing designators and not part of FAA's model identity. For the ADC-85/ADC-85A units, the commenter states that the correct models are Raytheon B200, B300, and 1900D, and that the Model C90A airplanes should be added to the list.

What Is FAA's Response to the Concern?

We concur with these comments and are changing this proposed rule accordingly.

Comment Issue No. 4: Add a Placard for Temporary Information Regarding the Unsafe Condition

What Is the Commenter's Concern?

A commenter states that the pilot should have some kind of indication of the problem if the actions specified in the service bulletin are not yet incorporated on the airplane (e.g., during the 12 calendar month time before mandatory compliance). This commenter suggests that FAA should require the operators to install a placard until the modification is incorporated.

What Is FAA's Response to the Concern?

The FAA does not concur. We evaluated the nature of the unsafe condition against the time proposed for compliance when preparing the NPRM. Rockwell Collins did issue Operator Bulletin 99-7, dated August 1999, which provides information on such a placard. Although it is a good idea to incorporate the actions of this operator bulletin, we have determined that the modification as proposed, including the compliance time, addresses the unsafe condition.

We will include a note in the proposed AD recommending compliance with Rockwell Collins Operator Bulletin 99-7, dated August 1999.

Comment Issue No. 5: Recommend the Effective Date of the AD to Accommodate Production Aircraft

What Is the Commenter's Concern?

A commenter recommends that FAA establish the effective date of the AD to accommodate incorporation of the AD into production aircraft. The commenter suggests May 1, 2001, or later, as the effective date of the AD.

What Is FAA's Response to the Concern?

The FAA will take this into consideration when establishing the effective date.

Comment Issue No. 6: Make Reference to a Later Service Bulletin for a More Complete List of Affected Units

What Is the Commenter's Concern?

A commenter states that Rockwell Collins Service Bulletin No. 62 (ADC-85/85A/850C/850D/850E/850F-34-62), Revision 2, dated March 7, 2000, contains a more complete list of affected units. The commenter recommends the incorporation of this service bulletin into the AD.

What Is FAA's Response to the Concern?

The FAA concurs that Revision 2 of the service bulletin contains a more complete list of affected ADC units. Revision 2 reflects the removal of ADC-850C from the affected list and adds ADC-850D to the affected list. However, Service Bulletin No. 62, dated October 25, 1999, is acceptable for ADC-85/85A/850F units. Service Bulletin No. 62, Revision 2, dated March 7, 2000, is acceptable for ADC-85/85A/850D/850F units. We will incorporate this bulletin into the proposed AD and change the proposed AD applicability accordingly.

The FAA's Determination

What Has FAA Decided?

After examining the circumstances and reviewing all available information related to the incidents described above, we have determined that:

—The unsafe condition exists or could develop on airplanes equipped with all ADC units identified in the E. Compliance section of Rockwell Collins Service Bulletin No. 62, Revision 2, dated March 7, 2000.

—The NPRM should be expanded to include these additional units; and

—AD action should be taken in order to correct this unsafe condition.

The Supplemental NPRM

How Will the Changes to the NPRM Impact the Public?

Proposing that the NPRM apply to certain ADC-850D air data computers that are installed on airplanes presents actions that go beyond the scope of what was already proposed. Therefore, we are issuing a supplemental NPRM and reopening the comment period to allow the public additional time to comment on the proposed AD.

What Are the Provisions of the Supplemental NPRM?

This proposed AD would require you to replace any affected ADC with one that has a reprogrammed and tested CPU circuit card and circuit card assemblies

Cost Impact

How Many Airplanes Would This Proposed AD Impact?

We estimate that this proposed AD affects more than 329 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 accomplish the proposed removal, installation, reprogramming, and testing of the ADC in each airplane:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
6 workhours × $60 per hour = $360	$680	$1040	$342,160

For units that are still under warranty, Rockwell will provide the parts and labor at no charge.

Regulatory Impact

Would This Proposed AD Impact Various Entities?

The regulations proposed herein 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. Therefore, it is determined that this proposed rule would not have federalism implications under Executive Order 13132.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

For the reasons discussed above, I certify that this proposed action (1) Is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action has been placed in the Rules Docket. A copy of it may be obtained by contacting 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

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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.

§ 39.13

[Amended]

2. FAA amends § 39.13 by adding a new airworthiness directive (AD) to read as follows:

Rockwell Collins, Inc.: Docket No. 2000-CE-14-AD.

(a) What airplanes are affected by this AD? This AD affects the following Rockwell Collins air data computers (ADC) that are installed in, but not limited to the airplanes that are listed below:

(1) Affected ADCs:

Unit	Collins part No. (CPN)	Applicable to serial No.
ADC-85 (Incorporating Rockwell Collins Service Bulletin No. 58)	622-8051-002 622-8051-003	All units.
ADC-85A (Incorporating Rockwell Collins Service Bulletin No. 58)	822-0370-113 822-0370-123 822-0370-139 822-0370-404 822-0370-408	All units.
ADC-850D (Incorporating Rockwell Collins Service Bulletin No. 58)	822-0389-133	All up to and including 3DGW (except for 1P6D, 22RC-22RF, and 23WK-3DGP).
ADC-850F	822-1036-406 822-1036-418	All units.

(2) List of airplanes where the affected ADC could be installed. This is not a comprehensive list and airplanes not on this list that have the ADC installed through field approval or other methods are still affected by this AD:

Unit	Airplane model
ADC-85/ADC-85A	Astra AIA. Chinese Y7 and Y8. Czech LET-610. DC-8. Falcon 20F. Piaggio P-180. Raytheon B200, B300, C90A and 1900D. Saab 340.
ADC-850D	Lear 60.
ADC-850F	Falcon 20, 50, and 50EX.

(b) Who must comply with this AD? Anyone who wishes to operate any airplane that uses one of the above referenced Rockwell Collins air data computers must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to prevent an unwarranted display of the ADC flag when switching static air sources. This could cause the flight crew to react to this incorrect flight information and possibly result in an unsafe operating condition.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

Actions	Compliance	Procedures
(1) Perform the following, unless already accomplished:
(i) Remove any affected ADC from the airplanes
(ii) As applicable, replace or reprogram parts or circuit card assemblies on central processing unit (CPU) circuit cards
(iii) Test the ADC
(iv) Install the modified ADC in the airplanes	Within the next 12 calendar months after the effective date of this AD	In accordance with Rockwell Collins Service Bulletin No. 62 (ADC-85/85A/850C/850D/850E/850F-34-62), Revision 2, dated March 7, 2000, or Service Bulletin No. 62, dated October 25, 1999, as applicable, the applicable Collins Computer Component Maintenance Manual, and Collins Avionics Standard Shop Practices Instruction Manual.
(2) Do not install on any airplane one of the affected ADCs unless the modification and test required by paragraphs (d)(ii) and (d)(iii) of this AD are accomplished	As of the effective date of this AD	In accordance with Rockwell Collins Service Bulletin No. 62 (ADC-85/85A/850C/850D/850E/850F-34-62), Revision 2, dated March 7, 2000, or Service Bulletin No. 62, dated October 25, 1999, as applicable.

Note 1:

Rockwell Collins Operator Bulletin 99-7, dated August 1999, contains information about an operational placard to install until accomplishment of the actions of this AD. While not necessary to address the unsafe condition in this AD, FAA highly recommends that you incorporate this placard.

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:

(1) Your alternative method of compliance provides an equivalent level of safety; and

(2) The Manager, Wichita Aircraft Certification Office (ACO), approves your alternative. Send your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO.

Note 2:

This AD applies to each airplane identified in paragraph (a) of this AD, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Roger A. Souter, FAA, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; facsimile: [phone], e-mail: [e-mail].

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) How do I get copies of the documents referenced in this AD? You may get copies of the documents referenced in this AD from Rockwell Collins, Business and Regional Systems, 400 Collins Road Northeast, Cedar Rapids, Iowa 52498. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on March 12, 2002.

Dorenda D. Baker,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.