Document ID: FAA-2008-0340-0003
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Avidyne Corporation Primary Flight Displays (Part Numbers 700-00006-000, -001, -002, -003, and -100)
Posted Date: 2008-04-14T04:00Z

[Federal Register: April 14, 2008 (Volume 73, Number 72)]
[Rules and Regulations]               
[Page 19963-19967]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14ap08-3]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0340; Directorate Identifier 2008-CE-020-AD; 
Amendment 39-15468; AD 2008-06-28 R1]
RIN 2120-AA64

 
Airworthiness Directives; Avidyne Corporation Primary Flight 
Displays (Part Numbers 700-00006-000, -001, -002, -003, and -100)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) to 
revise AD 2008-06-28, which applies to certain Avidyne Corporation 
(Avidyne) Primary Flight Displays (PFDs) (Part Numbers (P/Ns) 700-
00006-000, -001, -002, -003, and -100) that are installed on airplanes. 
AD 2008-06-28 currently requires you to do a check of the maintenance 
records and inspection of the PFD (if necessary) to determine if an 
affected serial number PFD is installed. If an affected serial number 
PFD is installed, this AD requires you to incorporate information that 
limits operation when certain conditions for the PFD or backup 
instruments exist. Since we issued AD 2008-06-28, we have learned that 
there is an incorrect serial number (SN) listed in AD 2008-06-28. 
Consequently, this AD retains the actions of AD 2008-06-28 and corrects 
the incorrect serial number. We are issuing this AD to prevent certain 
conditions from existing when PFDs display incorrect attitude, 
altitude, and airspeed information. This could result in airspeed/
altitude mismanagement or spatial disorientation of the pilot with 
consequent loss of airplane control, inadequate traffic separation, or 
controlled flight into terrain.

DATES: This AD becomes effective on April 10, 2008 (the effective date 
of AD 2008-06-28).
    We must receive any comments on this AD by June 13, 2008.

ADDRESSES: Use one of the following addresses to comment on this AD.
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    To get the service information identified in this AD, contact 
Avidyne Corporation, 55 Old Bedford Road, Lincoln, MA 01773; telephone: 
(781) 402-7400; fax: (781) 402-7599.
    To view the comments to this AD, go to http://www.regulations.gov. 
The docket number is FAA-2008-0340; Directorate Identifier 2008-CE-020-
AD.

FOR FURTHER INFORMATION CONTACT: Solomon Hecht, Aerospace Engineer, 
Boston Aircraft Certification Office, 12 New England Executive Park, 
Burlington, MA 01803; telephone: (781) 238-7159; fax: (781) 238-7170.

SUPPLEMENTARY INFORMATION: 

Discussion

    Several field reports of PFDs displaying incorrect altitude and 
airspeed information caused us to issue AD 2008-06-28, Amendment 39-
15440 (73 FR 15862, March 26, 2008). AD 2008-06-28 currently requires a 
check of the maintenance records and an inspection of the PFD (if 
necessary) to determine if an affected serial number PFD is installed. 
If an affected serial number PFD is installed, this AD requires you to 
incorporate information that limits operation when certain conditions 
for the PFD or backup instruments exist.
    We received several field reports of PFDs displaying incorrect 
altitude and airspeed information. These occurrences included incorrect 
display of information at system startup, including one or more of the 
following:
     Altitude significantly in error when compared to field 
elevation with local barometric correction setting entered on PFD.
     Altitude significantly in error when compared to backup 
altimeter with identical barometric correction settings.
     Non-zero airspeed (inconsistent with high winds or 
propwash from a nearby airplane) indicated at system startup.
     Altitude or airspeed indications that vary noticeably 
after startup under static conditions.
     Erroneous airspeed indications in combination with 
erroneous attitude indications.
     A steady or intermittent ``red X'' in place of the 
airspeed indicator, altimeter, vertical speed indicator, or attitude 
indicator.
    The conditions described above occur because of a manufacturing 
process defect on a certain batch of PFD serial numbers during 
incorporation of a design improvement on the air data unit assembly. 
The root cause of this manufacturing process defect is still being 
analyzed.
    Since we issued AD 2008-06-28, we have learned that PFD SN 0030197 
is incorrectly listed in AD 2008-06-28. The correct SN is 20030197.
    This condition, if not corrected, could result in airspeed/altitude 
mismanagement or spatial disorientation of the pilot and consequent 
loss of airplane control, inadequate traffic separation, or controlled 
flight into terrain.

FAA's Determination and Requirements of This AD

    We are issuing this AD because we evaluated all the information and 
determined the unsafe condition described previously is likely to exist 
or develop on other products of the same type design. This AD revises 
AD 2008-06-28 by retaining the actions of AD 2008-06-28 and correcting 
the incorrect serial number.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this

[[Page 19964]]

AD, we determined that notice and opportunity for public comment before 
issuing this AD are impracticable, and that good cause exists for 
making this amendment effective in fewer than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and an opportunity for 
public comment. We invite you to send any written relevant data, views, 
or arguments regarding this AD. Send your comments to an address listed 
under the ADDRESSES section. Include the docket number ``FAA-2008-0340; 
Directorate Identifier 2008-CE-020-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD. We will consider 
all comments received by the closing date and may amend the AD in light 
of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive concerning this AD.

Authority for This Rulemaking

    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 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD will 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.
    For the reasons discussed above, I certify that this AD:
    (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) 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 prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket that contains the AD, the regulatory 
evaluation, any comments received, and other information on the 
Internet at http://www.regulations.gov; or in person at the Docket 
Management Facility between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Office (telephone (800) 647-5527) 
is located at the street address stated in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by removing Airworthiness Directive (AD) 
2008-06-28, Amendment 39-15440 (73 FR 15862, March 26, 2008), and by 
adding a new AD to read as follows:

2008-06-28 R1 Avidyne Corporation: Amendment 39-15468; Docket No. 
FAA-2008-0340; Directorate Identifier 2008-CE-020-AD.

Effective Date

    (a) This AD becomes effective on April 10, 2008 (The effective 
date of AD 2008-06-28).

Affected ADs

    (b) This AD revises AD 2008-06-28; Amendment 39-15440.

Applicability

    (b) None.

Applicability

    (c) This AD applies to Avidyne Corporation (Avidyne) Primary 
Flight Displays (PFDs) (Part Numbers (P/Ns) 700-00006-000, 700-
00006-001, 700-00006-002, 700-00006-003, and 700-00006-100) that are 
installed on, but not limited to the following airplanes that are 
certificated in any category:
    (1) Adam Aircraft Model A500;
    (2) Cessna Aircraft Company Model 441 (STEC Alliant Supplemental 
Type Certificate (STC) No. SA09547AC-D incorporated);
    (3) Cessna Aircraft Company Models LC42-550FG and LC41-550FG 
(Columbia Aircraft Manufacturing and The Lancair Company previously 
held the type certificate for these airplanes);
    (4) Cirrus Design Corporation Models SR20 and SR22;
    (5) Diamond Aircraft Industries GmbH Model DA 40;
    (6) Hawker Beechcraft Corporation Model E90 (STEC Alliant STC 
No. SA09545AC-D incorporated);
    (7) Hawker Beechcraft Corporation Model 200 series (STEC Alliant 
STC No. SA09543AC-D incorporated); and
    (8) Piper Aircraft, Inc. Models PA-28-161, PA-28-181, PA-28R-
201, PA-32R-301 (HP), PA-32R-301T, PA-32-301FT, PA-32-301XTC, PA-34-
220T, PA-44-180, PA-46-350P, PA-46R-350T, and PA-46-500TP.

Unsafe Condition

    (d) This AD is the result of our learning that there is an 
incorrect serial number (SN) listed in AD 2008-06-28, which is 
corrected in this AD. We are issuing this AD to prevent certain 
conditions from existing when PFDs display incorrect attitude, 
altitude, and airspeed information. This could result in airspeed/
altitude mismanagement or spatial disorientation of the pilot with 
consequent loss of airplane control, inadequate traffic separation, 
or controlled flight into terrain.

Compliance

    (e) To address this problem, you must do the following, unless 
already done:

[[Page 19965]]

              Table 1.--Actions, Compliance, and Procedures
------------------------------------------------------------------------
             Actions                  Compliance          Procedures
------------------------------------------------------------------------
(1) Do a logbook check of         Within 15 days      The owner/operator
 maintenance records to            after April 10,     holding at least
 determine if any PFD (P/Ns 700-   2008 (the           a private pilot
 00006-000, 700-00006-001, 700-    effective date of   certificate as
 00006-002, 700-00006-003, or      AD 2008-06-28).     authorized by
 700-00006-100) with any                               section 43.7 of
 affected serial number listed                         the Federal
 in TABLE 2--Serial Numbers of                         Aviation
 Affected PFDs is installed.                           Regulations (14
(i) If, as a result of this                            CFR 43.7) may do
 check, you find any PFD                               the logbook
 installed with an affected                            check. Make an
 serial number, do the action                          entry into the
 required by paragraph (e)(3)(i)                       aircraft logbook
 or (e)(3)(ii) of this AD.                             showing
                                                       compliance with
                                                       this portion of
                                                       the AD in
                                                       accordance with
                                                       section 43.9 of
                                                       the Federal
                                                       Aviation
                                                       Regulations (14
                                                       CFR 43.9).
   (ii) If, as a result of this
    check, you cannot positively
    identify the serial number
    of the PFD, do the
    inspection required in
    paragraph (e)(2) of this AD
   (iii) If, as a result of this
    check, you positively
    identify that the PFD
    installed does not have a
    serial number affected by
    this AD, then no further
    action is required
(2) If you find, as a result of   Within 15 days      Not Applicable.
 the check required by paragraph   after April 10,
 (e)(1) of this AD you cannot      2008 (the
 positively identify the serial    effective date of
 number of the PFD, inspect any    AD 2008-06-28).
 PFD (P/Ns 700-00006-000, 700-
 00006-001, 700-00006-002, 700-
 00006-003, or 700-00006-100)
 for any affected serial number
 listed in TABLE 2--Serial
 Numbers of Affected PFDs. You
 may do the requirement of
 paragraph (e)(3) of this AD
 instead of this inspection
(3) If you find, as a result of   Within 15 days      The owner/operator
 the check required by paragraph   after April 10,     holding at least
 (e)(1) of this AD or the          2008 (the           a private pilot
 inspection required by            effective date of   certificate as
 paragraph (e)(2) of this AD,      AD 2008-06-28).     authorized by
 any PFD installed with an                             section 43.7 of
 affected serial number, do                            the Federal
 whichever of the following                            Aviation
 applies.                                              Regulations (14
(i) For airplanes with an                              CFR 43.7) may
 airplane flight manual (AFM),                         insert the
 pilot's operating handbook                            information into
 (POH), or airplane flight                             the AFM, POH,
 manual supplement (AFMS),                             AFMS, or
 incorporate the language in the                       maintenance
 Appendix of this AD into the                          records as
 Limitations section..                                 required in
(ii) For airplanes without an                          paragraph
 AFM, POH, or AFMS, do the                             (e)(3)(i) or
 following:.                                           (e)(3)(ii)(A) of
(A) Incorporate the language in                        this AD and/or
 the Appendix of this AD into                          fabricate the
 your aircraft records; and.                           placard required
(B) Fabricate a placard (using                         in paragraph
 at least \1/8\-inch letters)                          (e)(3)(ii)(B) of
 with the following words and                          this AD. Make an
 install the placard on the                            entry into the
 instrument panel within the                           aircraft records
 pilot's clear view: ``AD 2008-                        showing
 06-28 R1 CONTAINS LIMITATIONS                         compliance with
 REGARDING AVIDYNE PRIMARY                             these portions of
 FLIGHT DISPLAYS (PFD) AND                             the AD in
 REQUIRED INCORPORATION OF THESE                       accordance with
 LIMITATIONS INTO THE AIRCRAFT                         section 43.9 of
 RECORDS. YOU MUST FOLLOW THESE                        the Federal
 LIMITATIONS.''.                                       Aviation
                                                       Regulations (14
                                                       CFR 43.9).
(4) Do not install any PFD (P/Ns  As of April 10,     Not Applicable.
 700-00006-000, 700-00006-001,     2008 (the
 700-00006-002, 700-00006-003,     effective date of
 or 700-00006-100) with any        AD 2008-06-28).
 affected serial number listed
 in TABLE 2--Serial Numbers of
 Affected PFDs.
------------------------------------------------------------------------

    Note 1: If you have an AFM, POH, or AFMS, you may fabricate and 
install a placard as described in paragraph (e)(3)(ii) of this AD in 
addition to, but not instead of, the Limitations section requirement 
of paragraph (e)(3)(i) of this AD.

    Note 2: Avidyne Service Alert No. SA-08-001, dated February 12, 
2008, pertains to the subject matter of this AD. The service 
information cautions that all pilots should be vigilant in 
conducting proper preflight and in-flight checks of instrument 
accuracy.

[[Page 19966]]

       Table 2.--Serial Numbers of Affected PFDs AD 2008-06-28 R1
------------------------------------------------------------------------

-------------------------------------------------------------------------
D1023, D1031, D1037, D1069, D1075, D1080, D1084, D1090, D1101, D1102,
 D1106, D1112, D1115, D1136, D1138, D1141, D1144, D1158, D1170, D1172,
 D1174, D1178, D1188, D1197, D1199, D1212, D1234, D1240, D1249, D1253,
 D1254, D1256, D1259, D1260, D1262, D1270, D1272, D1277, D1283, D1288,
 D1313, D1319, D1327, D1351, D1364, D1380, D1387, D1391, D1396, D1405,
 D1412, D1428, D1433, D1434, D1435, F0006, F0011, F0021, F0030, F0031,
 F0032, F0035, 20002067, 20003147, 20003296, 20003316, 20004297,
 20005316, 20005487, 20008167, 20008227, 20008255, 20009297, 20009476,
 20010177, 20010255, 20011396, 20011456, 20012337, 20012506, 20013406,
 20014027, 20014227, 20015357, 20017286, 20018317, 20018425, 20018486,
 20019067, 20019297, 20020297, 20021067, 20021197, 20022177, 20022207,
 20022217, 20022286, 20022287, 20022296, 20023197, 20023377, 20024196,
 20024217, 20024297, 20024397, 20024407, 20024425, 20025067, 20025177,
 20025217, 20025317, 20026067, 20026197, 20026207, 20026265, 20026377,
 20026407, 20026506, 20027177, 20027226, 20027317, 20027377, 20028177,
 20028337, 20029177, 20029197, 20029246, 20029265, 20029506, 20030197,
 20030237, 20031207, 20031217, 20031406, 20031407, 20031516, 20032067,
 20032265, 20032337, 20032516, 20033337, 20034207, 20034327, 20035177,
 20036197, 20036237, 20036397, 20037265, 20037285, 20038127, 20038197,
 20038337, 20039177, 20040127, 20040177, 20040197, 20040265, 20040317,
 20041177, 20042197, 20042265, 20042317, 20042337, 20043197, 20043215,
 20043237, 20043247, 20044226, 20044237, 20044285, 20045215, 20045265,
 20045437, 20046215, 20047127, 20047147, 20047197, 20048197, 20048215,
 20048247, 20049147, 20049357, 20050147, 20050287, 20050346, 20050434,
 20051215, 20052215, 20053247, 20053257, 20053357, 20054247, 20054257,
 20054357, 20055087, 20056247, 20056257, 20057237, 20057346, 20058346,
 20061087, 20061247, 20062087, 20062247, 20063087, 20064087, 20064147,
 20064226, 20064337, 20066147, 20067087, 20068147, 20068337, 20069087,
 20071237, 20072087, 20073087, 20073346, 20073506, 20074207, 20075087,
 20075147, 20075207, 20076217, 20076257, 20077087, 20077506, 20078087,
 20078217, 20078257, 20078346, 20078496, 20084257, 20085396, 20087257,
 20089257, 20089346, 20090346, 20092297, 20093247, 20094107, 20094416,
 20097137, 20098037, 20099107, 20099346, 20099416, 20101416, 20102417,
 20103396, 20104246, 20106224, 20111224, 20112224, 20114416, 20115346,
 20116346, 20118416, 20123416, 20124456, 20126416, 20129346, 20135337,
 20139336, 20140336, 20142037, 20142296, 20146037, 20147336, 20153037,
 20158097, 20161097, 20164097, 20165097, 20166097, 20170097, 20170175,
 20172175, 20177175, 20202257, 20204175, 20209246, 20214175, 20216265,
 20217175, 20224175, 20224265, 20229265, 20232175, 20233175, 20236175,
 20236265, 20241175, 20243265, 20265355, 20272355, 20273355, 20278355,
 20281355, 20302384, 20308384, 20314384, 20317384, 20320305, 20321376,
 20330376, 20330384, 20343384, 20347305, 20348305, 20350305, 20356305,
 20359305, 20378475, 20380225, 20381225, 20382475, 20388225, 20402174,
 20403174, 20438345, 20440345, 20447425, 20452315, 20458315, 20462315,
 20467315, 20540094, 20550094, 20576445, 20580445, 20581445, 20582525,
 20584525, 20591525, 20595065, 20599065, 20605065, 20615116, 20618065,
 20638116, 20656284, 20732074, 20735176, 20739176, 20755493, 20814015,
 20815015, 20974365, 20978365, 20978434, 20986365, 20990434, 20998365,
 21002365, 21056395, 21060395, 21063184, 21063395, 21067184, 21070184,
 21075395, 21191045, 21200045, 21219045, 21294414, 21311414, 21315414,
 21324414, 21325414, 21330414, 21334414, 21340414, 21491056, 21493056,
 21596354, 21603435, 21604435, 21606435, 21608435, 21610435, 21614435,
 21646086, 21668086, 21812514, 21823514, 21826514, 21836304, 21839304,
 21852304, 22310186, 22378026, 22380026, 22398294, 22401294, 22405085,
 22412385, 22418026, 22418385, 22419026, 22470524, 22471524, 22472524,
 22479524, 22483524, 22486524, 22523204, 22525264, 22531204, 22559135,
 22568135, 22572135, 22578135, 22579135, 22586135, 22602135, 22603135,
 22608135, 22642493, 22647493, 22682076, 22908334, 22921334, 22961354,
 23166495, 23169495, 23173495, 23175495, 23182495, 23371455, 23378455,
 23443264, 23445264, 23448264, 23581244, 23602244, 23737136, 23738136,
 24021335, 24029335, 24231144, 24238144, 24248144, 24381324, 24478515,
 24735144, 24746144, 24750144, 24772085, 24773085, 24865155, 24867155,
 24870155, 24990084, 24991084, 24993084, 24996084, 25023034, 25027034,
 25522465, 25525465, 25530465, 25532465, 25538465, 25600465, 25618106,
 26287114, 26528095, 26547095, 26553095, 26569464, 26571095, 26572095,
 26584095, 26588464, 26592464, 27865034, 28478495, 28519495, 29019044,
 29023044, 29029044, 29031044, 29032044, 29512216, 29514216, and
 29522216.
------------------------------------------------------------------------

Alternative Methods of Compliance (AMOCs)

    (f) The Manager, Boston Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
ATTN: Solomon Hecht, Aerospace Engineer, Boston ACO, 12 New England 
Executive Park, Burlington, MA 01803; telephone: (781) 238-7159; 
fax: (781) 238-7170. Before using any approved AMOC on any airplane 
to which the AMOC applies, notify your appropriate principal 
inspector (PI) in the FAA Flight Standards District Office (FSDO), 
or lacking a PI, your local FSDO.

Additional Information

    (g) For the service alert referenced in this AD, contact Avidyne 
Corporation, 55 Old Bedford Road, Lincoln, MA 01773; telephone: 
(781) 402-7400; fax: (781) 402-7599.

Appendix to AD 2008-06-28 R1 Limitations Regarding Avidyne Primary 
Flight Displays (PFDs)

    Before conducting flight operations, pilots must review and be 
familiar with the Crosscheck Monitor section of the Avidyne Primary 
Flight Display Pilot's Guide and all limitations contained in the 
airplane flight manual, pilot's operating handbook, or aircraft 
operating handbook.
    As a normal practice, all pilots should be vigilant in 
conducting proper preflight and in-flight checks of instrument 
accuracy, including:
     Preflight check of the accuracy of both the primary and 
backup altimeter against known airfield elevation and against each 
other.
     Verification of airspeed indications consistent with 
prevailing conditions at startup, during taxi, and prior to takeoff.
     ``Airspeed alive'' check and reasonable indications 
during takeoff roll.
     Maintenance of current altimeter setting in both 
primary and backup altimeters.
     Cross-check of primary and backup altimeters at each 
change of altimeter setting and prior to entering instrument 
meteorological conditions (IMC).
     Cross-check of primary and backup altimeters and 
validation against other available data, such as glideslope 
intercept altitude, prior to conducting any instrument approach.
     Periodic cross-checks of primary and backup airspeed 
indicators, preferably in combination with altimeter cross-checks.
    For flight operations under instrument flight rules (IFR) or in 
conditions in which visual reference to the horizon cannot be 
reliably maintained (that is IMC, night operations, flight 
operations over water, in haze or smoke) and the pilot has reasons 
to suspect that any source (PFD or back-up instruments) of attitude, 
airspeed, or altitude is not functioning properly, flight under IFR 
or in these conditions must not be initiated (when condition is 
determined on the

[[Page 19967]]

ground) and further flight under IFR or in these conditions is 
prohibited until equipment is serviced and functioning properly.
    Operation of aircraft not equipped with operating backup (or 
standby) attitude, altimeter, and airspeed indicators that are 
located where they are readily visible to the pilot is prohibited.
    Pilots must frequently scan and cross-check flight instruments 
to make sure the information depicted on the PFD correlates and 
agrees with the information depicted on the backup instruments.

    Issued in Kansas City, Missouri, on April 4, 2008.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-7802 Filed 4-11-08; 8:45 am]

BILLING CODE 4910-13-P