Airworthiness Directives; Boeing Model 757 Series Airplanes Equipped With Rolls Royce RB211-535C Engines

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-143-AD; Amendment 39-8954; AD 94-14-02]

Airworthiness Directives; Boeing Model 757 Series Airplanes

Equipped With Rolls Royce RB211-535C Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain Boeing Model 757 series airplanes, that requires

tests of the thrust reverser system, and repair, if necessary;

installation of a modification that would terminate those tests; and

repetitive operational checks of that installation, and repair, if

necessary. This amendment is prompted by results of a safety review,

which revealed that in-flight deployment of a thrust reverser could

result in a significant reduction in the controllability of the

airplane. The actions specified by this AD are intended to prevent

deployment of a thrust reverser in flight and subsequent reduced

controllability of the airplane.

DATES: Effective August 1, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of August 1, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,

Washington 98124-2207; and Rolls-Royce plc, P.O. Box 31, Derby DE24

8BJ, England, ATTN: Technical Publications Department. This information

may be examined at the Federal Aviation Administration (FAA), Transport

Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,

Washington; or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jeffrey Duven, Aerospace Engineer,

Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,

Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056; telephone (206) 227-2688; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to certain Boeing Model 757 series

airplanes was published in the Federal Register on October 4, 1993 (58

FR 51589). That action proposed to require tests of the thrust reverser

system, and repair, if necessary; installation of a modification that

would terminate those tests; and repetitive operational checks of that

installation, and repair, if necessary. -

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter supports the proposed rule. -

Boeing requests that specific references to page numbers and

revision dates of the Boeing 757 Airplane Maintenance Manual (AMM) be

eliminated from the proposed rule, and that the proposal be amended to

include copies of the required test procedures so that reference to the

AMM would not be necessary. -

Boeing explains that the AMM's are customized for each operator to

reflect all of the equipment in that operator's fleet. Therefore, the

number of pages for any given procedure is variable, depending on the

number of different equipment configurations documented in an

operator's AMM. Boeing also indicates that AMM procedures are revised

periodically for non-technical reasons. Boeing adds that changes to the

structure of the procedures are necessary to accommodate an upgrade of

the publishing system that is currently under way, which, in addition

to repagination, will necessitate the issuance of revised AMM pages. -

Boeing states that the effect of specifying AMM page numbers and

revision dates in the AD is that operators may be unable to use the

procedure contained in the AMM to perform certain tests required by the

AD. Each operator would be required to maintain an obsolete version of

the procedure, or to request FAA approval of an alternative method of

compliance with the AD that would allow the use of the current version

of the AMM.

The FAA concurs partially. In light of the information submitted by

the commenter, the FAA finds that specific AMM page numbers and dates

should not be specified in the final rule. Therefore, such references

have been removed from paragraphs (a)(1) and (a)(2) of the final rule.

However, for those paragraphs, the FAA does not agree that copies of

the specific procedures should be included in the final rule.

Therefore, paragraphs (a)(1) and (a)(2) of the final rule have been

revised to cite only the appropriate section and task title specified

in the AMM for accomplishment of the tests required by those

paragraphs.

The FAA's objective in proposing periodic operational checks of the

sync-lock device, as specified in paragraph (c) of this AD, is to

ensure the integrity of the locking function. However, subsequent to

the issuance of the proposal and the receipt of Boeing's comments to

the proposal, Boeing has submitted to the FAA separate procedures for

accomplishment of the operational check of the sync-lock integrity.

These procedures have been defined in paragraph (c) of the final rule;

therefore, the AMM references specified in paragraph (c) of the NPRM

have been removed from the final rule. Additionally, the procedures for

the operational checks are accomplished independently of the other

thrust reverser system tests specified in the proposal. Accordingly,

the FAA has revised paragraph (c) of the final rule to require periodic

accomplishment of operational checks of the sync-lock integrity only,

and has removed the requirement for accomplishment of other tests

specified in that paragraph of the proposal. -

The Air Transport Association (ATA) of America, on behalf of its

members, states that, while ATA members are not opposed to

accomplishing the operational checks specified in paragraph (c) of the

proposal as part of their maintenance programs, these members are

opposed to accomplishing the checks as part of the requirements of an

AD. The commenters believe that the adoption of paragraph (c), as

proposed, is equivalent to issuing a Certification Maintenance

Requirements (CMR) item by means of an AD. -

ATA adds that, if the FAA finds sufficient justification to include

the requirement for operational checks in the AD, an alternative to

accomplishment of the checks should be provided in the final rule. ATA

reasons that an alternative is justified because no data exist to show

that repetitive checks of a modified thrust reverser cannot be handled

adequately through an operator's maintenance program. The suggested

alternative follows: Within 3 months after accomplishing the sync-lock

installation, revise the FAA- approved maintenance inspection program

to include an operational check of the sync-lock. The initial check

would be accomplished within 1,000 hours time-in-service after

modification. The AD would no longer be applicable for operators that

have acceptably revised the maintenance program. Operators choosing

this alternative could use an alternative recordkeeping method in lieu

of that required by Federal Aviation Regulation (FAR) 91.417 or 121.380

(14 CFR 91.417 or 121.380). The FAA would be defined as the cognizant

Principal Maintenance Inspector (PMI) for operators electing this

alternative.

One commenter, Boeing, requests that the proposed requirement for

operational checks be removed from the AD until the FAA reviews the

``more comprehensive'' scheduled maintenance recommendations developed

by the Model 757/767 Thrust Reverser Working Group, which will be

recommended in the next revision to the Maintenance Review Board (MRB)

report. Boeing believes that adoption of the maintenance

recommendations contained in that forthcoming revision will ensure that

an adequate level of safety (with regard to the sync-lock installation)

will be maintained by all operators of Model 757 series airplanes.

The FAA recognizes the concerns of these commenters regarding the

requirement for periodic operational checks of the sync-lock following

its installation. However, the FAA finds that the operational checks

are necessary in order to provide an adequate level of safety and to

ensure the integrity of the sync-lock installation. The actions

required by this AD are consistent with actions that have been

identified by an industry-wide task force as necessary to ensure

adequate safety of certain thrust reverser systems installed on

transport category airplanes. Representatives of the Aerospace

Industries Association (AIA) of America, Inc., and the FAA comprise

that task force. Representatives from other organizations, such as ATA,

have participated in various discussions and work activities resulting

from the recommendations of the task force.

The FAA acknowledges that the operational checks specified in this

AD and CMR items are similar in terms of scheduled maintenance and

recordkeeping. This AD addresses an unsafe condition and requires

installation of the sync-lock to correct that unsafe condition. The FAA

has determined that the requirement for operational checks is necessary

in order to ensure the effectiveness of that installation in addressing

the unsafe condition. This determination is based on the fact that the

sync-lock is a new design whose reliability has not been adequately

proven through service experience. In addition, service experience to

date has demonstrated that failures can occur within the sync-lock that

may not be evident during normal operation of the thrust reverser

system and may not result in activation of the sync-lock ``unlock''

indicator. The ATA's suggested alternative to accomplishment of the

operational checks would permit each operator to determine whether and

how often these checks should be conducted. In light of the severity of

the unsafe condition, however, the FAA has determined that allowing

this degree of operator discretion is not appropriate at this time.

Therefore, this AD is necessary to ensure that operators accomplish

checks of the integrity of the sync-lock installation in a common

manner and at common intervals.

The FAA also finds that addressing operational checks of the sync-

lock integrity in a recommended action, such as an MRB report, will not

ensure an acceptable level of safety with regard to the thrust reverser

system. However, the FAA recognizes that an operational check interval

of 4,000 hours time-in-service, which will be recommended by Boeing for

inclusion in the next revision to the MRB report, corresponds more

closely to the interval at which most of the affected operators conduct

regularly scheduled ``C'' checks. The FAA has reconsidered the proposed

interval of 1,000 hours time-in-service for accomplishment of

repetitive operational checks. In light of the safety implications of

the unsafe condition addressed and the practical aspects of

accomplishing orderly operational checks of the fleet during regularly

scheduled maintenance where special equipment and trained maintenance

personnel will be readily available, the FAA finds that accomplishment

of the checks at intervals of 4,000 hours time-in-service will provide

an acceptable level of safety. Paragraph (c) of the final rule has been

revised accordingly.

Since the issuance of the proposed rule, Boeing has issued Revision

2 of Service Bulletin 757-78-0035, dated June 23, 1994. The service

bulletin revision moves general work instruction Step B from Work

Package 2 to Step Q in Work Package 8. In Revision 1 of the service

bulletin, Step B of Work Package 2 specified procedures for removal of

the ground to the EICAS for the REV ISLN VAL message; however, the

ground should not be removed as part of Work Package 2. Rather, the

ground should be removed as part of Work Package 8 in order to avoid

loss of the REV ISLN VAL message on EICAS. Revision 2 of the service

bulletin correctly describes procedures for removal of the ground as

part of Work Package 8. Revision 2 of the service bulletin also

describes procedures for installation of an additional bracket on the

P36 disconnect bracket and to make a cutout on the P37 disconnect

bracket on certain airplanes.

The FAA has reviewed and approved this latest revision to the

service bulletin and has revised the final rule to reflect it as the

appropriate source of service information. The FAA finds that citing

this latest revision to the service bulletin will impose no additional

burden on any operator.

It should be noted that Revision 2 of Boeing Service Bulletin 757-

78-0035 references Rolls-Royce Service Bulletins RB.211-78-9725 and

RB.211-78-9726 as additional sources of service information for

accomplishment of the originally proposed sync-lock installation.

However, the Boeing service bulletin does not specify the appropriate

revision levels for the Rolls-Royce service bulletins. Therefore, the

FAA has added ``NOTE 1'' to paragraph (b) of this AD to specify that

the intent of that paragraph is that the appropriate revision levels

for the Rolls-Royce service bulletins that are to be used in

conjunction with Boeing Service Bulletin 757-78-0035 are as follows:

Rolls-Royce Service Bulletin RB.211-78-9725, dated June 23, 1993, or

Revision 1, dated January 7, 1994; and Rolls-Royce Service Bulletin

RB.211-78-9726, dated June 23, 1993, or Revision 1, dated October 1,

1993.

In addition, since the issuance of the proposed rule, Rolls-Royce

has issued Service Bulletin RB.211-78-9822, dated October 1, 1993. This

service bulletin describes procedures for installation of a revised

thrust reverser sync-lock. The FAA has determined that accomplishment

of the actions described in this service bulletin, in conjunction with

Boeing Service Bulletin 757-78-0035 [which was cited in paragraph (b)

of the proposal as the appropriate source of service information for

installation of an additional thrust reverser system locking feature],

constitutes an acceptable alternative to the sync-lock installation

specified in paragraph (b) of the proposal.

In light of this information, paragraph (b) of the final rule has

been revised to include paragraph (b)(1), which contains the

requirement for installation of an additional thrust reverser system

locking feature that was specified in the proposed rule, and paragraph

(b)(2), which provides for installation of a revised thrust reverser

sync-lock as an acceptable alternative to paragraph (b)(1) of this AD.

Accomplishment of the revised installation specified in paragraph

(b)(2) requires no additional work hours beyond the 514 work hours

specified in the economic impact information, below, for accomplishment

of the originally proposed sync-lock installation.

Additionally, it should be noted that Rolls-Royce Service Bulletin

RB.211-78-9822 references Rolls-Royce Service Bulletin RB.211-78-9726

as an additional source of service information for airplanes equipped

with Rolls-Royce RB211-535C engines. Rolls-Royce Service Bulletin

RB.211-78-9726 references Rolls-Royce Service Bulletin RB.211-78-9725

as an additional source of service information. However, the

appropriate revision levels for these service bulletins are not

specified in Boeing Service Bulletin 757-78-0035 or in any of the

Rolls-Royce service bulletins. Therefore, the FAA has added ``NOTE 2''

to paragraph (b) of the final rule to specify that the appropriate

revision levels for Rolls-Royce Service Bulletins RB.211-78-9726 and

RB.211-78-9725, used in conjunction with Rolls-Royce Service Bulletin

RB.211-78-9822, are as follows: Rolls-Royce Service Bulletin RB.211-78-

9726, dated June 23, 1993, or Revision 1, dated October 1, 1993; and

Rolls-Royce Service Bulletin RB.211-78-9725, dated June 23, 1993, or

Revision 1, dated January 7, 1994.

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the changes previously

described. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

There are approximately 40 Model 757 series airplanes of the

affected design in the worldwide fleet. Currently, there are no Model

757 series airplanes of the affected design on the U.S. Register.

However, should an affected airplane be imported and placed on the U.S.

Register in the future, it will take approximately 1 work hour per

airplane to accomplish the required auto restow and integrity tests,

514 work hours per airplane to accomplish either modification specified

in paragraph (b)(1) or (b)(2) of this AD, and 1 work hour per airplane

to accomplish the required operational checks; at an average labor rate

of $55 per work hour. Required parts are currently planned to be

supplied by the manufacturer at no cost to operators. Based on these

figures, the total cost impact of the AD is estimated to be $28,380 per

airplane.

The regulations adopted herein will 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 final

rule does 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) 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. A final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it may be obtained

from the Rules Docket at the location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to 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

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-14-02 Boeing: Amendment 39-8954. Docket 93-NM-143-AD.

Applicability: Model 757 series airplanes equipped with Rolls

Royce RB211-535C engines, as listed in Boeing Service Bulletin 757-

78-0035, Revision 2, dated June 23, 1994; certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent deployment of a thrust reverser in flight and

subsequent reduced controllability of the airplane, accomplish the

following:

(a) For airplanes on which the sync-lock feature has not been

installed as a modification in accordance with Boeing Service

Bulletin 757-78-0035: Within 4,000 hours time-in-service after the

effective date of this AD; and thereafter at intervals not to exceed

4,000 hours time-in-service until the modification required by

paragraph (b) of this AD is accomplished; accomplish paragraphs

(a)(1) and (a)(2) of this AD to verify proper operation of the

thrust reverser system. Prior to further flight, repair any

discrepancy found, in accordance with the procedures described in

the Boeing 757 Maintenance Manual.

(1) Perform a ``Thrust Reverser-Auto Restow Test'' in accordance

with the procedures described in Section 78-31-00 of the Boeing 757

Maintenance Manual.

(2) Perform an ``Actuator Lock and Crossover Shaft Integrity

Test'' in accordance with the procedures described in Section 78-31-

00 of the Boeing 757 Maintenance Manual.

(b) For airplanes on which the sync-lock feature has not been

installed as a modification in accordance with Boeing Service

Bulletin 757-78-0035: Within 5 years after the effective date of

this AD, accomplish the requirements of paragraph (b)(1) or (b)(2)

of this AD. Accomplishment of either of these installations

constitutes terminating action for the tests required by paragraph

(a) of this AD.

(1) Install an additional thrust reverser system locking feature

(sync-lock installation) in accordance with Boeing Service Bulletin

757-78-0035, Revision 2, dated June 23, 1994.

Note 1: Boeing Service Bulletin 757-78-0035 references Rolls-

Royce Service Bulletins RB.211-78-9725 and RB.211-78-9726 as

additional sources of service information. The intent of paragraph

(b)(1) of this AD is that the appropriate revision levels for the

Rolls-Royce service bulletins that are to be used in conjunction

with Boeing Service Bulletin 757-78-0035 are as follows: Rolls-Royce

Service Bulletin RB.211-78-9725, dated June 23, 1993, or Revision 1,

dated January 7, 1994; and Rolls-Royce Service Bulletin RB.211-78-

9726, dated June 23, 1993, or Revision 1, dated October 1, 1993.

(2) Install a revised thrust reverser sync-lock in accordance

with Boeing Service Bulletin 757-78-0035, Revision 2, dated June 23,

1994, and Rolls-Royce Service Bulletin RB.211-78-9822, dated October

1, 1993.

Note 2: Rolls-Royce Service Bulletin RB.211-78-9822 references

Rolls-Royce Service Bulletin RB.211-78-9726 as an additional source

of service information for airplanes equipped with Rolls-Royce

RB211-535C engines. Rolls-Royce Service Bulletin RB.211-78-9726

references Rolls-Royce Service Bulletin RB.211-78-9725 as an

additional source of service information. The FAA's intent is that

the appropriate revision levels of Rolls-Royce Service Bulletins

RB.211-78-9726 and RB.211-78-9725, used in conjunction with Rolls-

Royce Service Bulletin RB.211-78-9822, are as follows: Rolls-Royce

Service Bulletin RB.211-78-9726, dated June 23, 1993, or Revision 1,

dated October 1, 1993; and Rolls-Royce Service Bulletin RB.211-78-

9725, dated June 23, 1993, or Revision 1, dated January 7, 1994.

(c) Within 4,000 hours time-in-service after accomplishing the

modification required by paragraph (b) of this AD, or within 4,000

hours time-in-service after the effective date of this AD, whichever

occurs later; and thereafter at intervals not to exceed 4,000 hours

time-in-service: Accomplish the thrust reverser sync-lock integrity

test defined below to verify that the sync-locks have not failed in

the ``unlocked'' state. Prior to further flight, repair any

discrepancy found, in accordance with procedures described in the

Boeing 757 Maintenance Manual.

Thrust Reverser Sync-Lock Integrity Test

1. General

A. Use this procedure to test the integrity of the thrust

reverser sync locks. The procedure must be performed on each engine.

2. Thrust Reverser Sync Lock Test

A. Prepare for the thrust reverser sync lock test.

(1) Open the AUTO SPEEDBRAKE circuit breaker on the overhead

circuit breaker panel, P11.

(2) Do the steps that follow to supply power to the thrust

reverser system:

(a) Make sure the thrust levers are in the idle position.

(b) Make sure the thrust reversers are retracted and locked.

(c) Make sure these circuit breakers on the main power

distribution panel, P6, are closed:

(1) L ENG SYNC LOCK

(2) R ENG SYNC LOCK-ALTN

(d) Make sure these circuit breakers on the overhead circuit

breaker panel, P11, are closed:

(1) LANDING GEAR POS SYS 1

(2) T/R IND R

(3) T/R CONT-ALTN-R

(4) T/R IND L

(5) T/R CONT L

(6) R ENG SYNC LOCK

(7) T/R CONT R

(8) EICAS CMPTR LEFT

(9) EICAS UPPER IND

(10) EICAS CMPTR RIGHT

(11) EICAS LOWER IND

(12) EICAS DISPLAY SW

(13) EICAS PILOTS DSP

(14) AIR/GND SYS 1

(15) AIR/GND SYS 2

(16) LANDING GEAR POS SYS 2

(17) PROX SW TEST

(e) Supply electrical power.

(f) Supply pressure to the left (for the left engine) or right

(for the right engine) hydraulic system.

B. Do the thrust reverser sync lock test.

(1) Use the SENSOR CHANNEL SELECT thumb switches to set the PSEU

code for the auto-restow proximity sensor.

(a) On PSEU (-17), The left engine code is 433.

(b) On PSEU (-16), The left engine code is 105.

(c) The right engine PSEU code is 099.

Note: The following step will cause the Hydraulic Isolation

Valve (HIV) to open for approximately 5 seconds. The next 3 steps

must be done during this 5 second time. These 4 steps may be

repeated if required.

(2) Push the TARGET TEST switch on the PSEU and hold for one

second.

(3) Make sure the TARGET NEAR light on the PSEU comes on after

approximately four seconds.

(4) Make sure that the EICAS Advisory message L(R) REV ISLN VAL

shows for approximately 3 seconds and then does not show.

(5) Make sure the sync lock manual unlock lever on the right

sleeve of the reverser does not extend.

(6) Push and release the RESET switch on the PSEU.

(7) Open the applicable circuit breaker(s):

(a) For the left engine; L ENG SYNC LOCK (Panel P6)

(b) For the right engine; R ENG SYNC LOCK (Panel P11) R ENG SYNC

LOCK-ALTN (Panel P6)

(8) Move the left (right) reverse thrust lever up and rearward

to the reverse thrust position.

(9) Make sure that the thrust reverser does not extend.

(10) Move the left (right) reverse thrust lever to the forward

and down position.

C. Put the airplane back to its usual condition.

(1) Remove hydraulic pressure.

(2) Close the applicable circuit breaker(s).

(a) For the left engine; L ENG SYNC LOCK (Panel P6)

(b) For the right engine; R ENG SYNC LOCK (Panel P11) R ENG SYNC

LOCK-ALTN (Panel P6)

(3) Close the AUTO SPEEDBRAKE circuit breaker on the overhead

circuit breaker panel, P11.

(4) Remove electrical power.

D. Repeat the thrust reverser sync lock test on the other

engine.

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

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, Seattle Aircraft Certification

Office (ACO), FAA, Transport Airplane Directorate. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Seattle ACO.

Note 3: Information concerning the existence of approved

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

obtained from the Seattle ACO.

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

sections 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.

(f) The installation shall be done in accordance with Boeing

Service Bulletin 757-78-0035, Revision 2, dated June 23, 1994; and

Rolls-Royce Service Bulletin RB.211-78-9822, dated October 1, 1993.

This incorporation by reference was approved by the Director of the

Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part

51. Copies may be obtained from Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington 98124-2207; and Rolls-Royce plc,

P.O. Box 31, Derby DE24 8BJ, England, ATTN: Technical Publications

Department. Copies may be inspected at the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the

Office of the Federal Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

(g) This amendment becomes effective on August 1, 1994.

Issued in Renton, Washington, on June 22, 1994.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-15596 Filed 6-29-94; 8:45 am]

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