[Federal Register Volume 65, Number 191 (Monday, October 2, 2000)]
[Proposed Rules]
[Pages 58678-58680]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-25153]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-CE-14-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new 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 proposed AD would require you to replace 
any air data computer (ADC) with one that has reprogrammed and tested 
central processing unit (CPU) circuit card and circuit card assemblies. 
The proposed AD is the result of a flight test that showed that these 
ADC's could display an unwarranted ADC flag in response to the 
airplane's ``Normal/Alternate Air'' static source selection capability. 
The actions specified by the proposed AD are intended to prevent the 
ADC from displaying an unwarranted ADC flag when switching static air 
sources. This could cause the flight crew to deselect a valid alternate 
static air source during the time the unwarranted ADC flag is displayed 
and possibly result in the display of misleading information during 
critical operating situations.

DATES: The Federal Aviation Administration (FAA) must receive any 
comments on this proposed rule by November 6, 2000.

ADDRESSES: Send comments in triplicate 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 inspect comments 
at this location between 8 a.m. and 4 p.m., Monday through Friday, 
except holidays.
    You may get the service information referenced in the proposed AD 
from Rockwell Collins, Business and Regional Systems, 400 Collins Road 
Northeast, Cedar Rapids, Iowa 52498. You may read 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: (316) 946-4134; facsimile: (316) 946-4407. E-mail 
address: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    How do I comment on this AD? We invite your comments on the 
proposed rule. You may send whatever written data, views, or arguments 
you choose. You need to include the rule's docket number and send your 
comments in triplicate to the address specified under the caption 
ADDRESSES. We will consider all comments received by the closing date 
specified above, before acting on the proposed rule. We may change the 
proposals contained in this notice because of the comments received.
    Are there any specific portions of the AD I should pay attention 
to? The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule that 
might call for a need to change the proposed rule. You may read all 
comments we receive. We will file a report in the Rules Docket that 
summarizes each FAA contact with the public that concerns the 
substantive parts of this proposal.
    The FAA is reviewing the writing style we currently use in 
regulatory documents, in response to the Presidential memorandum of 
June 1, 1998. That memorandum requires federal agencies to communicate 
more clearly with the public. We are interested in your comments on the 
ease of understanding this document, and any other suggestions you 
might have to improve the clarity of FAA communications that affect 
you. You can get more information about the Presidential memorandum and 
the plain language initiative at http://www.faa.gov/language/.
    How can I be sure FAA receives my comment? If you want us to 
acknowledge the receipt of your 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 ADC's 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.

[[Page 58679]]

    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 ADC's include:

----------------------------------------------------------------------------------------------------------------
                                                                                          Production installed
                  Unit                        Part No.       Applicable to serial No.          serial No.
----------------------------------------------------------------------------------------------------------------
ADC-85.................................  622-8051-002, 622- All units................  None.
                                                  8051-003
ADC-85A................................  822-0370-113, 822- All units................  None.
                                            0370-123, 822-
                                            0370-139, 822-
                                            0370-404, 822-
                                                  0370-408
ADC-850C...............................  822-0374-121, 822- 1FWH and below, except     1B16 through 1P6C, 1LT6
                                            0374-135, 822-   1B16 through 1P6C.         and above.
                                            0374-407, 822-
                                                  0374-410
ADC-850F...............................  822-1036-406, 822- All Units................  None.
                                                  1036-418
----------------------------------------------------------------------------------------------------------------

    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.

Relevant Service Information

    What service information applies to this subject? Rockwell has 
issued Service Bulletin No. 62 (ADC-85/85A/850C/850F-34-62), dated 
October 25, 1999.
    What are the provisions of this service bulletin? The service 
bulletin contains procedures for replacing or reprogramming applicable 
parts or Circuit Card Assemblies on CPU Circuit Cards in the ADC and 
testing the modified ADC.

The FAA's Determination and an Explanation of the Provisions of the 
Proposed AD

    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 referenced in this document exists or could 
develop on airplanes equipped with either a Rockwell ADC-85, ADC-85A, 
ADC-850C, or ADC-850F ADC's;

--Any airplane with one of these ADC units should have the actions 
specified in the above service bulletin incorporated; and
--The FAA should take AD action to correct this unsafe condition.

    What does this proposed AD require? This proposed AD would 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.

Cost Impact

    How many airplanes does this proposed AD impact? We estimate the 
proposed AD would affect 245 airplanes in the U.S. registry.
    What is the cost impact of the proposed action for the affected 
airplanes on the U.S. Register? We estimate that it would take about 1 
workhour per airplane to remove the ADC. We estimate that it would take 
about 1 workhour to install the ADC in the airplane.
    We estimate that it would take about 1 workhour per airplane to do 
the proposed installation and reprogramming and about 3 workhours per 
airplane to do the proposed testing at an average labor rate of $60 an 
hour. Parts to do this action cost up to $680. Based on the figures 
presented above, we estimate the total cost impact of the proposed 
action on U.S. operators is $254,800, or $1,040 per airplane.
    For units that are still under warranty, Rockwell will provide the 
parts and labor at no charge.

Regulatory Impact

    Does this proposed AD impact relations between Federal and State 
governments? The proposed regulations would not have substantial direct 
effects 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. It is 
determined that this proposed rule would not have federalism 
implications under Executive Order 13132.
    Does 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 Department of 
Transportation Regulatory Policies and Procedures (44 FR 11034, 
February 26, 1979); and (3) if put into effect 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. We have placed a copy of the draft regulatory 
evaluation prepared for this action in the Rules Docket. You may get a 
copy of it 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 (FAA) 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.


Sec. 39.13  [Amended]

    2. FAA amends Section 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? The following 
Rockwell Collins air data computers (ADC) that are installed in, but 
not limited to the airplanes that are listed below:
    (1) Affected ADC's:

[[Page 58680]]



----------------------------------------------------------------------------------------------------------------
                                                                                          Production installed
                  Unit                        Part No.       Applicable to serial No.          serial No.
----------------------------------------------------------------------------------------------------------------
ADC-85.................................  622-8051-002, 622- All Units................  None.
                                                  8051-003
ADC-85A................................  822-0370-113, 822- All Units................  None.
                                            0370-123, 822-
                                            0370-139, 822-
                                            0370-404, 822-
                                                  0370-408
ADC-850C...............................  822-0374-121, 822- 1FWH and below, except     1B16 through 1P6C, 1LT6
                                            0374-135, 822-   1B16 through 1P6C.         and above.
                                            0374-407, 822-
                                                  0374-410
ADC-850F...............................  822-1036-406, 822- All Units................  None.
                                                  1036-418
----------------------------------------------------------------------------------------------------------------

    (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 King 250, 350, and
                                             1900, 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 on the U.S. Register that uses one of the above 
referenced Rockwell 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 must I do to address this problem? To address this 
problem, you must accomplish the following actions:

------------------------------------------------------------------------
             Actions               Compliance times       Procedures
------------------------------------------------------------------------
(1) Remove any affected ADC from  Within 1 year       Do these actions
 the airplane.                     after the           in accordance
                                   effective date of   with Rockwell
                                   this AD.            Collins Service
                                                       Bulletin No. 62
                                                       (ADC-85/85A/850C/
                                                       850F-34-62),
                                                       dated October 25,
                                                       1999, the
                                                       applicable
                                                       Collins Computer
                                                       Component
                                                       Maintenance
                                                       Manual, and
                                                       Collins Avionics
                                                       Standard Shop
                                                       Practices
                                                       Instruction
                                                       Manual.
(2) As applicable, replace or
 reprogram parts or Circuit Card
 assemblies on Central
 Processing Unit Circuit Cards.
(3) Test the ADC................
(4) Install the modified ADC in
 the airplane.
(5) Do not install on any         As of the           Use the procedures
 airplane one of the affected      effective date of   in the referenced
 ADC's unless the modification     this AD.            service
 and test required by paragraphs                       information.
 (d)(2) and (d)(3) of this AD
 are accomplished.
------------------------------------------------------------------------

    (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, 
1801 Airport Road, Rm 100, Wichita, Kansas 67209, 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: This AD applies to each airplane with a Rockwell air data 
computer 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. You should include in the request 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? You can contact Roger A. Souter, 
FAA, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, 
Rm 100, Wichita, Kansas 67209; telephone: (316) 946-4134; facsimile: 
(316) 946-4407, E-mail: [email protected].
    (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 obtain copies of the documents referenced in this AD from 
Rockwell Collins, Business and Regional Systems, 400 Collins Road 
Northeast, Cedar Rapids, Iowa 52498; or may read this document at 
FAA, Central Region, Office of the Regional Counsel, 901 Locust, 
Room 506, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on September 26, 2000.
Michael K. Dahl,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-25153 Filed 9-29-00; 8:45 am]
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