Airworthiness Directives; Raytheon Aircraft Company Model 1900D Airplane (Formerly Known as Beech Aircraft Corporation Model 1900D Airplane)

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-68-AD]

RIN 2120-AA64

Airworthiness Directives; Raytheon Aircraft Company Model 1900D

Airplane (Formerly Known as Beech Aircraft Corporation Model 1900D

Airplane)

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 Raytheon Aircraft Company (Raytheon) Models

1900D airplanes (formerly known as Beech Aircraft Corporation Models

1900D airplanes). The proposed action would require inspecting and

repairing the radio switching panel relay printed circuit board (PCB)

and the nose avionics wire harnesses, and replacing the existing A017

component PCB with a new A017 component PCB that has internal

overcurrent protection fuses. Several reported incidents of lost pilot/

co-pilot intercom ability, VHF communication ability, and public

address system ability while in flight prompted the proposed action.

The actions specified by the proposed AD are intended to prevent the

loss of the pilot and co-pilot intercom, VHF communications, and

passenger address system, which could result in loss of all

communication during critical phases of flight.

DATES: Comments must be received on or before March 14, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Central Region, Office of the Regional Counsel,

Attention: Rules Docket No. 97-CE-68-AD, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106. Comments may be inspected at this location

between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

Service information that applies to the proposed AD may be obtained

from Raytheon Aircraft Company, P. O. Box 85, Wichita, Kansas 67201-

0085; telephone (800) 625-7043. This information also may be examined

at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Harvey Nero, Aerospace Engineer,

Wichita Aircraft Certification Office, Room 100, 1801 Airport Rd.,

Wichita,

[[Page 3279]]

Kansas 67209; telephone (316) 946-4137; facsimile (316) 946-4407.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications should identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed rule. All

comments submitted will be available, both before and after the closing

date for comments, in the Rules Docket for examination by interested

persons. A report that summarizes each FAA-public contact concerned

with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket No. 97-CE-68-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Central Region, Office of the Regional Counsel, Attention:

Rules Docket No. 97-CE-68-AD, Room 1558, 601 E. 12th Street, Kansas

City, Missouri 64106.

Discussion

The FAA has received several incident reports in which an in-flight

overcurrent condition occurred in the avionics/communications equipment

resulting in a loss of certain Raytheon Model 1900D airplanes' pilot

and co-pilot intercom, VHF communication, and passenger address

systems. Investigation of these incidents found that one of the

avionics wire harnesses had become chafed by rubbing against the PCB

rack in the forward avionics bay. Investigators also found overcurrent

conditions opening PCB traces in Collins CTL-22 communication control

heads.

These events are occurring because the manufacturer made a change

in the configuration design and installation of the avionics/

communication equipment and the wire harnesses on the Model 1900D

airplanes. The new configuration reduced the space between the

equipment and made the proper installation of the wire harnesses a more

critical issue. Also, the communication control heads are not

internally protected by fuses to prevent a short circuit on any of the

distribution circuits from affecting the entire communication system.

This design makes it possible for an electrical short in the radio

switching panel relay PCB's or in the avionics harnesses to create an

overcurrent condition in the CTL-22 communication control heads.

This condition could cause the pilot and co-pilot circuit breaker

to open, resulting in the pilot and co-pilot intercom system, VHF

communications, and the passenger address system not operating,

resulting in the loss of communication during critical phases of

flight.

Relevant Service Information

Raytheon has issued service bulletin (SB) No. 2643, dated August,

1996, which specifies procedures for:

inspecting the electrical connectors, the radio switching

panel, and this panel's relay PCB's for moisture and corrosion;

if moisture is found, cleaning and drying the components;

if corrosion is found, either cleaning or replacing the

component, depending on the severity;

if moisture or corrosion is found, locating and

eliminating the source;

inspecting the nose avionics wire harnesses for proper

installation, and if any wire harness is not installed properly,

securing it with cable ties; and

removing the A017 component PCB, part number (P/N) 101-

342536-1, and replacing it with a new A017 component PCB, P/N 101-

342536-5 (or an approved FAA-equivalent part number).

The FAA's Determination

After examining the circumstances and reviewing all available

information related to the incidents described above including the

referenced service information above, the FAA has determined that AD

action should be taken to prevent the loss of the pilot and co-pilot

intercom, VHF communications, and passenger address system during

critical flight, which could result in loss of all communication during

critical phases of flight.

Explanation of the Provisions of the Proposed AD

Since an unsafe condition has been identified that is likely to

exist or develop in other Raytheon Model 1900D airplanes of the same

type design, the proposed AD would require: (1) Inspecting the radio

switching panel and nose avionics wire harnesses for moisture and

corrosion; (2) removing the corrosion; (3) locating and correcting the

source of the moisture that is causing the corrosion; (4) repairing or

replacing the corroded part; and, (5) replacing the A017 component PCB

with a new A017 component PCB that has internal overcurrent protection

fuses. Accomplishment of the proposed AD would be in accordance with

Raytheon Service Bulletin (SB) No. 2643, dated August, 1996.

Cost Impact

The FAA estimates that 160 airplanes in the U.S. registry would be

affected by the proposed AD, that it would take approximately 4

workhours per airplane to accomplish the proposed action, and that the

average labor rate is approximately $60 an hour. Parts cost

approximately $370 per airplane. Based on these figures, the total cost

impact of the proposed AD on U.S. operators is estimated to be $97,600

or $610 per airplane.

Raytheon has informed the FAA that they have shipped approximately

127 A017 component PCB's to the owners/operators of the affected

airplanes. With this information in mind, the FAA would presume that

127 of the airplanes have already accomplished the proposed action,

thereby reducing the total cost impact of the proposed AD on U.S.

operators by $77,470 from $97,600 to $20,130.

Regulatory Impact

The regulations proposed herein 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. Therefore, in

accordance with Executive Order 12612, it is determined that this

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this 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

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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, pursuant to 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive

(AD) to read as follows:

Raytheon Aircraft Company: Docket No. 97-CE-68-AD.

Applicability: Model 1900D airplanes (serial numbers UE-1

through UE-160), certificated in any category.

Note 1: This AD applies to each airplane identified in the

preceding applicability provision, 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 the unsafe condition has not been

eliminated, the request should include specific proposed actions to

address it.

Compliance: Required within the next 1,000 hours time-in-service

(TIS) after the effective date of this AD, unless already

accomplished.

To prevent the loss of the pilot and co-pilot intercom, VHF

communications, and passenger address system, which could result in

loss of all communication during critical phases of flight,

accomplish the following:

(a) Inspect the electrical connectors, the radio switching panel

and its relay printed circuit boards (PCB's) for moisture and

corrosion in accordance with the Accomplishment Instructions in

Raytheon Service Bulletin (SB) No. 2643, dated August, 1996.

(1) If moisture is found, prior to further flight, clean and dry

the component in accordance with the Accomplishment Instructions in

Raytheon Service Bulletin (SB) No. 2643, dated August, 1996.

(2) If corrosion is found, prior to further flight, either clean

or replace the component, depending on the severity, in accordance

with the Accomplishment Instructions in Raytheon Service Bulletin

(SB) No. 2643, dated August, 1996.

(3) If moisture or corrosion is found, prior to further flight,

locate and eliminate the source (i.e., crack, hole, leak) in

accordance with the Accomplishment Instructions in Raytheon Service

Bulletin (SB) No. 2643, dated August, 1996.

(b) Inspect the nose avionics wire harnesses for proper

installation, and if any wire harness is not installed properly,

prior to further flight, secure it with cable ties in accordance

with the Accomplishment Instructions in Raytheon Service Bulletin

(SB) No. 2643, dated August, 1996.

(c) Remove the A017 component PCB, part number (P/N) 101-342536-

1, and replace the PCB with a new A017 component PCB (P/N 101-

342536-5 or an FAA-approved equivalent part number) in accordance

with the Accomplishment Instructions in Raytheon Service Bulletin

(SB) No. 2643, dated August, 1996.

(d) Special flight permits may be issued in accordance with

Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to a location where the

requirements of this AD can be accomplished.

(e) An alternative method of compliance or adjustment of the

compliance time that provides an equivalent level of safety may be

approved by the Manager, Wichita Aircraft Certification Office, Room

100, 1801 Airport Rd., Wichita, Kansas 67209. The request shall be

forwarded through an appropriate FAA Maintenance Inspector, who may

add comments and then send it to the Manager, Wichita Aircraft

Certification Office.

Note 2: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Wichita Aircraft Certification Office.

(f) All persons affected by this directive may obtain copies of

the document referred to herein upon request to Raytheon Aircraft

Company, P.O. Box 85, Wichita, Kansas 67201-0085; or may examine

this document at the FAA, Central Region, Office of the Regional

Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on January 14, 1998.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.

[FR Doc. 98-1461 Filed 1-21-98; 8:45 am]

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