[Federal Register Volume 69, Number 9 (Wednesday, January 14, 2004)]
[Rules and Regulations]
[Pages 2059-2062]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-474]



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  Federal Register / Vol. 69, No. 9 / Wednesday, January 14, 2004 / 
Rules and Regulations  

[[Page 2059]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-CE-16-AD; Amendment 39-13427; AD 2004-01-13]
RIN 2120-AA64


Airworthiness Directives; Raytheon Aircraft Company Model 1900, 
1900C, and 1900D Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA supersedes Airworthiness Directive (AD) 97-22-16, 
which applies to certain Raytheon Model 1900, 1900C, and 1900D 
airplanes. AD 97-22-16 currently requires you to replace the bearings 
on the vent blower assemblies with improved design bearings and install 
a thermal protection device for the vent blowers. That AD resulted from 
reports of vent blower assembly bearings seizing and locking the blower 
motor on several of the affected airplanes. This AD retains the actions 
required in AD 97-22-16 for certain vent blower assemblies and requires 
you to incorporate further product improvement modifications on all 
affected vent blower assemblies. This AD is the result of reports that 
vent blower assemblies modified in accordance with AD 97-22-16 are 
still malfunctioning. We are issuing this AD to prevent smoke from 
entering the cockpit and cabin due to the current configuration of vent 
blower assemblies, which could result in the pilot becoming 
incapacitated or impairing her/his judgment. Such a condition could 
lead to the pilot not being able to make critical flight safety 
decisions and result in loss of control of the airplane.

DATES: This AD becomes effective on February 19, 2004.
    As of February 19, 2004, the Director of the Federal Register 
approved the incorporation by reference of certain publications listed 
in the regulation.

ADDRESSES: You may get the service information identified in this AD 
from Raytheon Aircraft Company, 9709 E. Central, Wichita, Kansas 67201-
0085; telephone: (800) 429-5372 or (316) 676-3140.
    You may view the AD docket at FAA, Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 2003-CE-16-AD, 901 
Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. 
to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Dan Withers, Aerospace Engineer, 
Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Wichita, 
Kansas 67209; telephone: (316) 946-4196; facsimile: (316) 946-4107.

SUPPLEMENTARY INFORMATION:

Discussion

    What events have caused this AD? Reports of the vent blower 
assembly bearings seizing and locking the blower motor on several 
Raytheon Model 1900, 1900C, and 1900D airplanes caused us to issue AD 
97-22-16, Amendment 39-10187 (62 FR 58894, October 31, 1997. AD 97-22-
16 currently requires the following on certain Raytheon Model 1900, 
1900C, and 1900D airplanes:

--Incorporating a modification to replace the bearings in the vent 
blower assemblies with improved design bearings (Electromech 
Technologies Kit No. EM630-201-1 or EM630-201-2 (as appropriate for the 
blower serial number)); and
--Installing a thermal protection for the vent blowers (Electromech 
Technologies Kit No. EM630-201-1 or EM630-201-2 or Advanced Industries 
Kit No. BC80A905 (as appropriate for the blower serial number)).

    What has happened since AD 97-22-16 to initiate this action? The 
FAA has received reports that vent blower assemblies modified in 
accordance with AD 97-22-16 are still malfunctioning.
    What is the potential impact if FAA took no action? If not 
corrected, smoke could enter the cockpit and cabin, which could result 
in the pilot becoming incapacitated or impairing her/his judgment. This 
condition could lead to the pilot not being able to make critical 
flight safety decisions and result in loss of control of the airplane.
    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 Raytheon Model 1900, 1900C, 
and 1900D airplanes. This proposal was published in the Federal 
Register as a notice of proposed rulemaking (NPRM) on June 4, 2003 (68 
FR 33420). The NPRM proposed to supersede AD 97-22-16 with a new AD 
that would retain the actions required in AD 97-22-16 for certain vent 
blower assemblies and require you to incorporate further product 
improvement modifications for all affected vent blower assemblies.

Comments

    Was the public invited to comment? We provided the public the 
opportunity to participate in the development of this AD. The following 
presents the comments received on the proposal and FAA's response to 
each comment:

Comment Issue: The Proposed AD Does Not Solve the Problem of Smoke in 
the Cockpit/Cabin

    What is the commenter's concern? The commenter states that the 
proposed AD focuses on the vent blower low speed resistors and does not 
consider the motor as a source of smoke. Since the cooling air for the 
motor is drawn through the motor by the blower intake and then is 
exhausted into the cabin, any motor failure that generates smoke and 
fumes is blown directly into the cabin.
    The following summarizes the commenter's concerns:

--The insulation on the lead-wire can hang up on the brush holder if 
the brush lead-wire is pushed down to clear the metal brush inspection 
cover. The installation instructions provided with Modification Kit 
BC80A-901-3, which incorporates the replacement brushes with the lead-
wire insulation, do not clarify where the lead-wires should be formed;
--When a brush lead-wire gets hung up on the brush holder (caused by 
improper lead-wire forming), there is little to no force from the 
spring to hold the brush against the

[[Page 2060]]

commutator. Lack of force to hold the brush against the commutator can 
cause arcing between the brush and commutator surface, which produces 
tremendous heat and accelerated brush wear. This will ultimately lead 
to excess heat that will cause the grease to boil out of the bearings 
and result in bearing failure;
--The hard anodized coating on the metal brush inspection cover 
provided with Modification Kit No. 630-203-1 is a poor insulator and is 
easily scratched during assembly and disassembly. Once scratched, the 
coating offers no insulation, which creates the possibility for a short 
circuit to the brush shunt; and
--The low speed power resistors are considered undersized for the 
application.

    The commenter recommends the following:

--Installing thermal fuse(s) on the motor to interrupt the current in 
the event of the motor overheating;
--Controlling how the brush lead-wires are formed to prevent shorting 
to metal inspection screen or any other adjacent conductor; and
--Increasing the power rating of the low speed resistors to improve the 
safety margin.

    The commenter requests these changes based on personal repair 
history as well as analysis of the design.

    What is FAA's response to the concern? We do not agree. Although 
the commenter raises many pertinent concerns, we consider the requested 
changes a product improvement or a way to increase the reliability of 
the motor.
    The proposed AD is intended to address smoke in the cabin/cockpit 
that is specifically caused by the vent blower assembly. Investigation 
by Raytheon engineering concluded that all incidents involving smoke in 
the cockpit/cabin were caused by overheating of the vent blower low 
speed resistors while operating the blower on low speed.
    AD 97-22-16 required incorporating the applicable modification kit 
as specified in Raytheon Service Bulletin No. 2721, Issued: January, 
1997. Raytheon Service Bulletin No. 2721 added a 216[deg]C thermal 
cutout to the resistor assembly to interrupt power to the resistors and 
prevent overheating.
    Further field experience revealed that the 216[deg]C cutout may not 
open soon enough to prevent overheating in all instances. As a result, 
Raytheon issued Mandatory Service Bulletin SB 21-3448, Issued: October, 
2002, to decrease the thermal cutout set point to 152[deg]C. New tests 
verified that this value cutout to the resistor assembly provides 
adequate protection against resistor overheating while avoiding 
nuisance trips during normal operation.
    The addition of an insulating sleeve over the brush lead-wires and 
hard anodizing of the brush inspection cover required by Raytheon 
Mandatory Service Bulletin SB 21-3448, Issued: October, 2002, was done 
to offer an additional measure of protection. The additions are not 
meant to substitute proper brush lead-wire routing.
    The thermal cutout on the resistors and the aircraft's blower 
circuit current limiter are the primary methods of protection. If a 
brush lead-wire was shorted to the housing and the vent blower was 
operated in the low speed mode, the increased current flow would cause 
the resistor temperature to increase until the thermal cutout opens and 
interrupts power to the resistors. If a brush lead-wire was shorted to 
the housing and the vent blower was operated in the high speed mode, 
the increased current flow would cause the aircraft's current limiter 
to open and interrupt power.
    A brush lead-wire could possibly get hung up with or without the 
sleeving. If the brush lead-wire gets hung up, this would result in 
arcing between the brush and commutator resulting in increased heat and 
accelerated brush wear until the blower no longer continues to operate. 
At this time, the manufacturer has not received any field reports of 
smoke related to ``hung brushes.''
    The power dissipation in the low speed circuit does appear to be 
above the rated value for the resistors. However, this does not account 
for the large amount of cooling airflow that passes over the area to 
which the resistors are mounted. Service history shows that the 
resistor rating is adequate under normal operations. If the resistors 
start to overheat because of vent blower failure, then the thermal 
cutout will open and interrupt power to the resistor assembly.
    Since none of the recommendations specifically address an unsafe 
condition, we have determined that we are not changing the final rule 
AD based on these comments.

Conclusion

    What is FAA's final determination on this issue? We have carefully 
reviewed the available data and determined that air safety and the 
public interest require adopting the AD as proposed except for minor 
editorial corrections. We have determined that these minor corrections:

--Are consistent with the intent that was proposed in the NPRM for 
correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already 
proposed in the NPRM.

Changes to 14 CFR Part 39--Effect on the AD

    How does the revision to 14 CFR part 39 affect this AD? On July 10, 
2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, 
July 22, 2002), which governs the 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 does this AD impact? We estimate that this AD 
affects 300 airplanes in the U.S. registry.
    What is the cost impact of this AD on owners/operators of the 
affected airplanes? We estimate the following costs to accomplish the 
modification:

----------------------------------------------------------------------------------------------------------------
                                                                       Total cost per      Total cost on U.S.
               Labor cost                          Parts cost             airplane             operators
----------------------------------------------------------------------------------------------------------------
3 workhours x $60 per hour = $180.......  $415 (for both the forward             $595     $595 x 300 = $178,500.
                                           and aft ventilation blower
                                           assemblies).
----------------------------------------------------------------------------------------------------------------

Regulatory Findings

    Will this AD impact various entities? We have 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.

[[Page 2061]]

    Will this AD involve a significant rule or regulatory action? 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 the 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 summary of the costs to comply with this AD 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 
``AD Docket No. 2003-CE-16-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends part 39 of the Federal 
Aviation Regulations (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. FAA amends Sec.  39.13 by removing Airworthiness Directive (AD) 97-
22-16, Amendment 39-10187 (62 FR 58894, October 31, 1997), and by 
adding a new AD to read as follows:

2004-01-13 Raytheon Aircraft Company: Amendment 39-13427; Docket No. 
2003-CE-16-AD; Supersedes AD 97-22-16, Amendment 39-10187.

When Does This AD Become Effective?

    (a) This AD becomes effective on February 19, 2004.

What Other ADs Are Affected by This Action?

    (b) This AD supersedes AD 97-22-16, Amendment 39-10187 (62 FR 
58894, October 31, 1997).

What Airplanes Are Affected by This AD?

    (c) This AD affects the following airplane models and serial 
numbers that are:
    (1) certificated in any category; and
    (2) equipped with vent blower assembly, part number 114-380028-
1, 114-380028-3, 114-380028-5, or 114-380028-7.

------------------------------------------------------------------------
                 Model                           Serial numbers
------------------------------------------------------------------------
1900..................................  UA-3.
1900C.................................  UB-1 through UB-74 and UC-1
                                         through UC-174.
1900 (C-12J)..........................  UD-1 through UD-6.
1900D.................................  UE-1 through UE-427.
------------------------------------------------------------------------

What Is the Unsafe Condition Presented in This AD?

    (d) This AD is the result of reports that vent blower assemblies 
modified in accordance with AD 97-22-16 are still malfunctioning. 
The actions specified in this AD are intended to prevent smoke from 
entering the cockpit and cabin due to the current configuration of 
vent blower assemblies, which could result in the pilot becoming 
incapacitated or impairing his/her judgment. This condition could 
lead to the pilot not being able to make critical flight safety 
decisions and result in loss of control of the airplane.

What Must I Do To Address This Problem?

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

------------------------------------------------------------------------
             Actions                  Compliance          Procedures
------------------------------------------------------------------------
(1) Check the maintenance         Within the next     Follow Raytheon
 records to determine if a part    800 hours time-in-  Aircraft
 number (P/N) 114-380028-1, 114-   service (TIS)       Mandatory Service
 380028-3, 114-380028-5, or 114-   after February      Bulletin SB 21-
 380028-7 ventilation blower       19, 2004 (the       3448, Issued:
 assembly is installed.            effective date of   October, 2002.
                                   this AD), unless    The owner/
                                   already done.       operator holding
                                                       at least a
                                                       private pilot
                                                       certificate as
                                                       authorized by
                                                       section 43.7 of
                                                       the Federal
                                                       Aviation
                                                       Regulations (14
                                                       CFR 43.7) may
                                                       perform this
                                                       check.
(2) If, by checking the           Prior to further    The owner/operator
 maintenance records, the owner/   flight after the    holding at least
 operator can definitely show      maintenance         a private pilot
 that a P/N 114-380028-1, 114-     records check       certificate as
 380028-3, 114-380028-5, or 114-   required in         authorized by
 380028-7 ventilation blower       paragraph (e)(1)    section 43.7 of
 assembly is not installed, no     of this AD.         the Federal
 further action is required by                         Aviation
 this AD. Make an entry into the                       Regulations (14
 aircraft records showing                              CFR 43.7) may
 compliance with this portion of                       make this entry.
 the AD in accordance with
 section 43.9 of the Federal
 Aviation Regulations (14 CFR
 43.9).
(3) If, by checking the           Do all              Following Raytheon
 maintenance records, the owner/   modifications       Aircraft
 operator can definitely show      prior to further    Mandatory Service
 that a P/N 114-380028-1, 114-     flight after the    Bulletin SB 21-
 380028-3, 114-380028-5, or 114-   maintenance         3448, Issued:
 380028-7 ventilation blower       records check       October, 2002,
 assembly is installed, do the     required in         and Raytheon
 following for each P/N:.          paragraph (e)(1)    Service Bulletin
                                   unless already      No. 2721, Issued:
                                   done.               January, 1997.
(i) P/N 114-380028-1: modify
 following Raytheon Service
 Bulletin No. 2721, Issued:
 January, 1997, prior to
 incorporating Electromechanic
 Technologies Modification Kit
 No. P/N 630-203-01 and changing
 the P/N to 114-380028-11.
(ii) P/N 114-380028-3:
 incorporate Advanced Industries
 Modification Kit No. P/N BC80A-
 901-3 and change the P/N to 114-
 380028-9.
(iii) P/N 114-380028-5 with a
 serial number (S/N) of 2162 or
 above or with a S/N of 2162
 with an ``A'' suffix: no
 modification is required.
 Change the P/N to 114-380028-11
 and make an entry into the
 aircraft records that shows
 compliance with this portion of
 the AD in accordance with
 section 43.9 of the Federal
 Aviation Regulations (14 CFR
 43.9).

[[Page 2062]]

 
(iv) P/N 114-380028-5 with a S/N
 prior to 2162 without an ``A''
 suffix: incorporate
 Electromechanic Technologies
 Modification Kit No. P/N 630-
 203-01 and change the P/N to
 114-380028-11.
(v) P/N 114-380028-7:
 incorporate Advanced Industries
 Modification Kit No. P/N BC80A-
 901-3 and change the P/N to 114-
 380028-9.
(4) If the owner/operator cannot  Inspect within the  Follow Raytheon
 definitely show that a P/N 114-   next 800 hours      Aircraft
 380028-1, 114-380028-3, 114-      TIS after           Mandatory Service
 380028-5, or 114-380028-7         February 19, 2004   Bulletin SB 21-
 ventilation blower assembly is    (the effective      3448, Issued:
 installed through the             date of this AD).   October, 2002,
 maintenance records check, an     Do all              and Raytheon
 appropriately-rated mechanic      modifications       Service Bulletin
 must do an inspection to          prior to further    No. 2721, Issued:
 determine the P/N of the          flight.             January, 1997.
 installed ventilation blower
 assembly and do the applicable
 modification required in
 paragraphs (e)(3)(i),
 (e)(3)(ii), (e)(3)(iii),
 (e)(3)(iv), and (e)(3)(v) of
 this AD.
(5) Do not install any P/N 114-   As of February 19,  Follow Raytheon
 380028-1, 114-380028-3, 114-      2004 (the           Aircraft
 380028-5, or 114-380028-7         effective date of   Mandatory Service
 ventilation blower assembly,      this AD).           Bulletin SB 21-
 unless it has been modified as                        3448, Issued:
 specified in paragraphs                               October, 2002,
 (e)(3)(i), (e)(3)(ii),                                and Raytheon
 (e)(3)(iii), (e)(3)(iv), and                          Service Bulletin
 (e)(3)(v) of this AD.                                 No. 2721, Issued:
                                                       January, 1997.
------------------------------------------------------------------------

May I Request an Alternative Method of Compliance?

    (f) You may request a different method of compliance or a 
different compliance time for this AD by following the procedures in 
14 CFR 39.13.
    (1) Send your request to the Manager, Wichita Aircraft 
Certification Office (ACO), FAA. For information on any already 
approved alternative methods of compliance, contact Dan Withers, 
Aerospace Engineer, Wichita Aircraft Certification Office, FAA, 1801 
Airport Road, Wichita, Kansas 67209; telephone: (316) 946-4196; 
facsimile: (316) 946-4107.
    (2) Alternative methods of compliance approved in accordance 
with AD 97-22-16, which is superseded by this AD, are not approved 
as alternative methods of compliance with this AD.

Does This AD Incorporate Any Material by Reference?

    (g) You must do the actions required by this AD following the 
instructions in Raytheon Aircraft Mandatory Service Bulletin SB 21-
3448, Issued: October, 2002, and Raytheon Aircraft Mandatory Service 
Bulletin No. 2721, Issued: January, 1997. 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. You may get a copy from Raytheon Aircraft Company, 9709 E. 
Central, Wichita, Kansas 67201-0085; telephone: (800) 429-5372 or 
(316) 676-3140. You may review copies at FAA, Central Region, Office 
of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 
64106; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

    Issued in Kansas City, Missouri, on January 2, 2004.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-474 Filed 1-13-04; 8:45 am]
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