Source: https://www.federalregister.gov/documents/2005/12/12/05-23771/airworthiness-directives-shadin-adc-2000-air-data-computers
Timestamp: 2017-08-23 05:39:37
Document Index: 612745701

Matched Legal Cases: ['art 39', 'art 39', 'art 135', 'art 135', 'art 135', 'art 51']

73355-73358 (4 pages)
Amendment 39-14401
AD 2005-25-08
Comment Issue No. 1: AD Should Apply to Only Airplanes Operating Under IFR
Comment Issue No. 2: Remove All Affected ADCs Until Upgraded
https://www.federalregister.gov/d/05-23771 https://www.federalregister.gov/d/05-23771
The FAA adopts a new airworthiness directive (AD) for certain Shadin ADC-2000 air data computers (ADC) installed on airplanes. This AD requires you to replace affected ADC-2000 units with a modified unit. This AD results from reports that certain ADC-2000 units display incorrect altitude information on the Electronic Flight Information System (EFIS) to the pilot. We are issuing this AD to prevent ADC-2000 units, part numbers (P/Ns) 962830A-1-S-8, 962830A-2-S-8, and 962830A-3-S-8, 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.
To get the service information identified in this AD, contact Shadin, 6831 Oxford Street, St. Louis Park, Minnesota 55426-4412; telephone: (800) 388-2849 or (952) 927-6500; facsimile: (952) 924-1111; e-mail: http://www.shadin.com.
To view the AD docket, go to the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001 or on the Internet at http://dms.dot.gov. The docket number is FAA-2005-21787; Directorate Identifier 2005-CE-34-AD.
What events have caused this AD? We received reports that the pressure altitude output of certain Shadin ADC-2000 air data computers (ADC) drift outside Technical Standard Order (TSO) tolerance.
The maximum altitude error allowed by TSO-C106 and TSO-C44a is 25 feet at ground level. Shadin ADC-2000 units, P/Ns 962830A-1-S-8, 962830A-2-S-8, and 962830A-3-S-8, configurations B, C, and D have shown errors from 100 to 8,000 feet from the correct altitude.
We 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.
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 Shadin ADC-2000 air data computers (ADC) installed on airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 17, 2005 (70 FR 48333). The NPRM proposed to require you to replace affected ADC-2000 units with a modified unit.
Was the public invited to comment? We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment: Start Printed Page 73356
What is the commenter's concern? The commenter is concerned that 14 CFR 43.7 does not allow part 135 operators to do the preflight check required in paragraph (e)(1) of the proposed AD. This would require a maintenance mechanic to be hired to do the preflight check before each flight.
The commenter requests that airplanes flown under part 135 VFR operations be excluded from complying with the AD by changing the Compliance column from “before each flight” to “before each IFR flight.”
What is FAA's response to the concern? We do not agree with the commenter. Under 14 CFR 43.7, paragraph (e), part 135 operators are allowed to return an airplane to service.
To avoid confusion, which could result in unnecessarily grounding some of the affected airplanes, we are removing the reference to 14 CFR 43.7 from the Procedures column in paragraph (e)(1) of the proposed AD.
What is the commenter's concern? The commenter states that the ADC provides input into the Terrain Awareness and Warning System (TAWS).
To prevent the possibility of incorrect ADC data being input into the TAWS, the commenter wants FAA to require removal of all affected ADCs until they are upgraded.
What is FAA's response to the concern? We do not agree with the commenter. The Shadin ADC altitude error has occurred over a long period of time. We do not have justification to require removing the affected ADCs before further flight.
We use compliance times such as this when we have identified an urgent safety of flight situation. We believe that 25 hours TIS will give the owners or operators of the affected airplanes enough time to have the actions required by this AD done without compromising the safety of the airplanes.
The altimetry system checks provided as an interim solution to the actions required in paragraph (e)(2) is a normal aircraft preflight check.
Where can I go to view the docket information? You may view the AD docket that contains information relating to this subject in person at the DMS Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone 1-800-647-5227) 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.
How many airplanes does this AD impact? We estimate that this AD affects 457 airplanes in the U.S. registry.
2 work hours X $65 per hour = $130 Not applicable $130 $130 X 457 = $59,410.
We prepared a summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “Docket No. FAA-2005-21787; Start Printed Page 73357Directorate Identifier 2005-CE-34-AD” in your request.
2005-25-08 SHADIN: Amendment 39-14401; Docket No. FAA-2005-21787; Directorate Identifier 2005-CE-34-AD.
Alliance Aircraft Group, LLC H-250
B-N Group Ltd BN2A
Bombardier Inc DHC-3, DHC-6
Cessna Aircraft Company 172, 180, 180E, 185, 206, 206E, 206F, 206G 208, 210L, 310
deHavilland Inc DHC-2
The New Piper Aircraft, Inc PA-28-180, PA-28-181, PA-31-350, PA-32-300, PA-32-301, PA-32R-300, PA-34-200T
(1) To ensure the air data computer (ADC) and the Electronic Flight Information System (EFIS) altimetry accuracy, do the normal preflight check. If the altitudes, altimeter, and elevation differ by more than 75 feet, do not fly the airplane in Instrument Meterological Conditions (IMC)/Instrument Flight Rules (IFR) Within the next 25 hours time-in-service (TIS) after January 23, 2006 (the effective date of this AD) and thereafter before each flight until the ADC is upgraded as specified in paragraph (e)(2) of this AD Follow the Interim Procedures contained in Shadin Service Bulletin SB28-05-002, Rev C, dated June 29, 2005. The owner/operator holding at least a private pilot certificate may do the check specified in paragraph (e)(1) of this AD. Make an entry into the aircraft records showing compliance with this portion of the AD following section 43.9 of the Federal Aviation Regulations (14 CFR 43.9).
(2) Return all Shadin ADC-2000s, part numbers 962830A-1-S-8, 962830A-2-S-8, 962830A-3-S-8, Configurations B, C, and D, to the Shadin Repair Facility for upgrade. Contact the Shadin Technical Support department for a Return Merchandise Authorization (RMA) number. Until the ADC-2000 is modified, returned, and reinstalled, only fly the airplane if equipment requirements for that airplane are still met Within the next 15 months after January 23, 2006 (the effective date of this AD) Follow Shadin Service Bulletin SB28-05-002, Rev C, dated June 29, 2005.
(3) Do not install any Shadin ADC-2000, part number 962830A-1-S-8, 962830A-2-S-8, or 962830A-3-S-8, Configurations B, C, and D, unless it has been upgraded as specified in paragraph (e)(2) of this AD As of January 23, 2006 (the effective date of this AD) Not applicable.
(g) You must do the actions required by this AD following the instructions in Shadin Service Bulletin SB28-05-002, Rev C, dated June 29, 2005. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get a copy of this service information, contact Shadin, 6831 Oxford Street, St. Louis Park, Minnesota 55426-4412; telephone: (800) 388-2849 or (952) 927-6500; facsimile: (952) 924-1111; e-mail: http://www.shadin.com. To review copies of this service information, go to the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html or call (202) 741-6030. To view the AD docket, go to the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Start Printed Page 73358Nassif Building, Room PL-401, Washington, DC 20590-001 or on the Internet at http://dms.dot.gov. The docket number is FAA-2005-21787; Directorate Identifier 2005-CE-34-AD.
[FR Doc. 05-23771 Filed 12-9-05; 8:45 am]