This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents. Prices of

new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

59561

Vol. 62, No. 213

Tuesday, November 4, 1997

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM–25; Special Conditions No.

25–ANM–16A]

Special Conditions: Boeing Model 747

Series Airplanes; Overhead Crew Rest

Area

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Amended special conditions.

SUMMARY: These amended special

conditions are issued to the Boeing

Commercial Airplane Company for the

Model 747 series airplanes. This

airplane has a novel or unusual design

feature associated with the overhead

crew rest area. Special Conditions No.

25–ANM–16 were issued on November

13, 1987, addressing this installation.

On January 23, 1997, Boeing applied for

a type design change which proposes to

add an additional feature; the

installation of curtains or partitions in

the crew rest area. Since the applicable

airworthiness regulations, including

those contained in Special Conditions

No. 25–ANM–16, do not contain

adequate or appropriate safety standards

for this particular design feature, these

amended special conditions contain the

additional safety standards which the

Administrator finds necessary to

establish a level of safety equivalent to

that established by the airworthiness

standards for transport category

airplanes.

EFFECTIVE DATE: October 23, 1997.

FOR FURTHER INFORMATION CONTACT: Greg

Dunn, FAA, Transport Standards Staff,

Standardization Branch, ANM–113,

1601 Lind Avenue SW., Renton, WA

98055–4056; telephone (425) 227–2799,

or facsimile (425) 227–1149.

SUPPLEMENTARY INFORMATION:

Background

On December 17, 1986, the Boeing

Commercial Airplane Company applied

for a change to Type Certificate No.

A20WE to include Model 747 series

airplanes with overhead crew rest areas

installed. The crew rest area was to be

installed above the main passenger

cabin in the vicinity of the Number 5

passenger door. This is an area that had

not been used for this purpose in any

previous transport category airplane.

Due to the novel or unusual features

associated with the installation of those

crew rest areas, Special Conditions No.

25–ANM–16 were issued on November

13, 1987, to provide a level of safety

equal to that established by the

regulations incorporated by reference in

the type certificate. Upon issuance,

Special Conditions No. 25–ANM–16

became part of the regulations

incorporated by reference in Type

Certificate No. A20WE for Boeing 747

series airplanes.

Boeing Commercial Airplane Group

now proposes certification of overhead

crew rest areas that would be divided

into three sections by a hard partition

and a curtain. These crew rest areas,

which would be in the same location,

would be designated for in-flight use

only and would include additional

novel or unusual design features not

incorporated in the previous crew rest

areas. Because of these additional

features, the regulations incorporated by

reference in Type Certificate No.

A20WE, including Special Conditions

25–ANM–16, do not contain adequate or

appropriate safety standards. Special

Conditions 25–ANM–16 would,

therefore, be amended to contain the

additional safety standards found

necessary to establish a level of safety

equivalent to that established in the

regulations.

Discussion

A hard partition separates the crew

rest area into forward and aft sections

while a door in the partition provides

access between the forward and aft

sections. A curtain slides in the forward

and aft directions to visually divide the

aft section of the crew rest area. Item 3

of Special Conditions No. 25–ANM–16

requires that a stairway be installed

between the main deck and the crew

rest area. Additionally, there must be an

alternate evacuation route for occupants

of the crew rest area, located on the

opposite side of the crew rest area or

sufficiently separated within the

compartment from the stairway. The

installation of a hard partition creates an

area within the crew rest area which

does not have a means of egressing

directly to the main cabin.

In addition to the partition, a curtain

has been added to the crew rest area

which further breaks up the crew rest

area into sections. This was not

considered in Special Conditions No.

25–ANM–16. The curtain and partition

installation also reduces the

accessibility to the emergency

equipment and communication

controls, and has the potential to

prevent the occupants from being able

to easily locate the primary and

secondary escape means. This could

cause additional confusion during an

emergency.

Since the installation of a door in the

crew rest area raises concerns about

operational reliability during an inflight emergency and since the related

paragraphs of § 25.819 from which the

original special conditions were

developed require two evacuation

routes, design features must be provided

to assure that occupants of the forward

section will be able to vacate the crew

rest area in the event of an in-flight

emergency. Additional emergency

equipment and two-way communication

equipment will also be required in the

forward section since the equipment in

the aft area will not be readily accessible

to the forward section occupants in the

event of an in-flight emergency.

A limitation in the Airplane Flight

Manual or other suitable means

requiring that crewmembers be trained

in the use of the evacuation routes

would be required.

The additional safety standards are

contained in Item 13 of these amended

special conditions. Items 1 through 12

are standards already adopted in Special

Conditions No. 25–ANM–16.

Type Certification Basis

The Type Certification Basis for the

Boeing Model 747 series prior to the

747–400 is Part 25 of the FAR effective

February 1, 1965, as amended by

Amendments 25–1 through 25–8, plus

Amendments 25–15, 25–17, 25–18, 25–

20, and 25–39, with certain exceptions

and several sets of special conditions,

which are identified in Type Certificate

Data Sheet No. A20WE. These
59562 Federal Register / Vol. 62, No. 213 / Tuesday, November 4, 1997 / Rules and Regulations

exceptions are not pertinent to the

subject of overhead crew rest areas.

The regulations incorporated by

reference in Type Certificate No.

A20WE for the Boeing Model 747–400

series airplanes include Part 25 of the

FAR as amended by Amendments 25–1

through 25–59, with certain exceptions

not relevant to the installation of an

overhead crew rest area.

In addition, the regulations

incorporated by reference for all 747

series include the noise certification

requirements of Part 36 of the FAR,

emission standards, and a number of

special conditions, including Special

Conditions No. 25–ANM–16.

If the Administrator finds that the

applicable airworthiness regulations

(i.e., Part 25 as amended) do not contain

adequate or appropriate safety standards

for the Boeing Model 747 because of a

novel or unusual design feature, special

conditions are prescribed under the

provisions of § 21.16.

Special conditions, as appropriate, are

issued in accordance with § 11.49 of the

FAR after public notice, as required by

§§ 11.28 and 11.29(b), and become part

of the type certification basis in

accordance with § 21.101(b)(2).

Discussion of Comments

Notice of Proposed Special

Conditions No. SC–97–4–NM for the

Boeing Model 747 series airplanes, was

published in the Federal Register on

August 28, 1997 (62 FR 45589).

Fourteen comments (from 4 different

commenters) were received.

Four comments were submitted by

The Boeing Company. One seeks to

limit the applicability of the new

requirements in Item 13 to new designs

and wants clarification that prior

certified designs should be exempt from

the revisions to the special condition.

The FAA is not aware of any previously

certified crew rest configurations that

are divided into sections by a partition

with a door. However, the FAA agrees

that the requirements of Item 13 are

only applicable to new designs. Existing

designs approved by Type Certificate

(TC) or by Supplemental Type

Certificate (STC) are not required to be

modified and can continue to be

delivered without any retroactive

changes. Any new TC or STC projects

that modify an existing crew rest area or

install a crew rest area into a previously

certificated aircraft will be required to

comply with the new requirements

contained in Item 13, if the rest area is

divided into sections. Since Item 13

contains requirements pertaining only

to crew rest areas that are divided into

sections, the requirements for crew rest

areas not divided into sections are

unchanged.

Another comment suggests that Item

13, paragraph a., should be revised to

prevent confusion. Paragraph a. states,

‘‘* * * there must be an audible alert

concurrent with automatic presentation

of supplemental oxygen masks in each

section of the crew rest, * * *’’.

Currently it is unclear whether the

alerting method and/or the

supplemental oxygen masks are

required in each section of the crew rest

area. The intent of paragraph a. was to

require automatically presented

supplemental oxygen in each section of

the crew rest area. The presentation of

the supplemental oxygen masks must be

accompanied by an alert that can be

heard in each section of the crew rest

area. Paragraph a. has been revised to

allow one alerting device to serve more

than one section, provided it can clearly

be heard in each section. Paragraph a.

has also been clarified to identify that

the supplemental oxygen masks are

required in each section of the crew rest

area.

Another comment objects to the

requirement in Item 13, paragraph e.,

that requires doors installed between

partitions to be frangible from either

direction. It was proposed to change the

requirement to state that, ‘‘All doors

installed must be designed to preclude

anyone from being trapped inside the

compartment.’’ This proposed revision

identifies door performance criteria

rather than a specific design solution.

The proposed revision is also consistent

with the requirement that was applied

to the 777–200 Lower Lobe Attendant

Rest. For this crew rest area, Boeing

proposes alternate means to open the

partition door in the event it is jammed

or inoperable. The door can be removed

from the aft side by disconnecting the

hinge pins. From the front side the

striker mechanism can be defeated to

open the door and access the evacuation

routes. The FAA concurs with the

comment. These alternative means of

opening a jammed or blocked door are

acceptable, and that consideration

should be given to designs that meet the

proposed performance criteria rather

than require partition doors to be

frangible from both sides. Item 13,

paragraph e., of these amended special

conditions has been revised

accordingly.

Another comment seeks to change the

requirements contained in Item 13,

paragraph f. This paragraph requires

two-way voice communication

equipment and additional emergency

equipment in each section of a crew rest

created by the installation of a hard

partition with a door. The proposed

revision suggests that the additional

equipment should only be required in

section(s) that did not provide an escape

route to the main deck. The rationale

was that the overall area of the crew rest

is unchanged, so the only reason the

additional equipment would be needed

is if the partition door were inoperable

(blocked or jammed). If the door were

blocked or jammed, the alternate escape

route could be used, precluding the

necessity for the additional two-way

communication equipment and

emergency equipment. The FAA

disagrees this is the only reason to

install the additional equipment. There

are several other scenarios that the FAA

has considered. There may be a need for

the main deck flightcrew to alert the

occupants of the crew rest area to an inflight emergency in the passenger cabin.

In this case, a phone in each section

needs to be readily accessible. Another

situation that may occur is the need for

additional emergency equipment to

fight a fire just outside a partition door.

Accepting this comment could result in

circumstances where a flight attendant

may be forced to evacuate a crew rest

area rather than retrieve the emergency

equipment and fight a fire. This would

be unacceptable. In this type of an

emergency the two-way voice

communication equipment is also

necessary so that backup personnel can

be contacted.

Two comments were received from a

company that modifies aircraft interiors

by STC projects. One comment was

similar to the previously addressed

comment regarding the requirements for

frangible doors. The commenter thinks

the requirement for a two-way frangible

door is too restrictive and that other

means of preventing entrapment within

a compartment should be allowed. The

commenter suggests that Item 13,

paragraph e., could be applied to a

lavatory door installed in the crew rest

area. For an application such as a

lavatory door, it was suggested that a

removable panel in the door could

adequately provide a means by which

entrapment could be prevented. As

discussed previously, the FAA agrees

that other means to prevent entrapment

should be considered and has revised

Item 13, paragraph e., accordingly.

This commenter also suggests that the

requirement for additional emergency

equipment contained in Item 13,

paragraph f., should not be applied to a

small section such as a lavatory, since

a lavatory is not expected to be

occupied for extended periods of time.

The FAA agrees with this comment and

has revised Item 13, paragraph f.,

accordingly. In addition, Item 13,

paragraph f., has also been revised using
Federal Register / Vol. 62, No. 213 / Tuesday, November 4, 1997 / Rules and Regulations 59563

the above rationale to remove the

requirement for additional two-way

voice communication equipment in

areas that are only meant to be

temporarily occupied.

A representative from the Association

of Flight Attendants (AFA) submitted

several comments. A summary of the

AFA’s position is that a crew rest area

that is divided into sections by

partitions and doors does not provide

the same level of safety as the ‘‘open’’

configuration that was initially certified.

One comment from the AFA was that

the hard partition and curtain block the

lines of sight within the crew rest area.

The visual obstructions could then

reduce the situational awareness within

the individual sections, should an

emergency develop. The example given

by the commenter is that with the

previously approved open area, if a fire

were to break out, all occupants would

be able to immediately assess conditions

throughout the crew rest area. The

commenter also expresses concern that

the partition and curtains would limit

visibility of the primary and secondary

evacuation routes. Although the

situational awareness from visibility

between the sections may be reduced,

the FAA’s position is that the new

requirements for additional smoke

detectors, decompression alarms, twoway voice communication equipment,

and public address (PA) systems audible

in each section adequately compensate

for the reduced visibility. These systems

will adequately alert the crew rest area

occupants to emergencies in the crew

rest area and to emergencies on the

main deck of the aircraft.

In order to compensate for reduced

visibility of the escape routes, exit signs

have been required in each section of

the crew rest area to assist the occupants

in locating the primary exit. It should

also be noted that the occupants of this

crew rest area are required by Item 12

of these special conditions to receive

additional training in the use of both the

primary and alternate evacuation routes.

After considering the requirement for

additional occupant training, the

additional signs required by Item 13,

paragraphs d. and e., and the small

confines of the overhead crew rest area,

it has been determined that the

installation of the hard partition and

curtain are very unlikely to create a

situation where the occupants would

not be able to locate either of the escape

routes. To assure that future

installations don’t propose what could

be envisioned as a maze within the

overhead crew rest area, Item 13,

paragraph e., prohibits arrangements

that would require the occupants to pass

through more than one door before

reaching the primary exit.

Another comment opposes

installation of the partition door because

of concerns for entrapment and the

potential of the door to become a barrier

to evacuation. There is no specific time

requirement for evacuating the overhead

crew rest area since it is not allowed to

be occupied for taxi, takeoff and

landing. Boeing has conducted

certification testing that has shown that

the door in the hard partition can be

opened or removed should the door

become blocked or jammed. The hinge

pins can be removed from the aft side,

and the striker mechanism can be

defeated from the forward side; these

operations can be accomplished in

several seconds and are contrary to

comments suggesting these features are

difficult to operate. Since the door can

be opened or removed in several

seconds, the door cannot be considered

an entrapment hazard or an impediment

to egress. It should be noted that similar

hinge pin designs and striker defeat

mechanisms have been previously

approved for other crew rest areas and

lavatories.

A comment was also made that the

door hinge pins should be relocated to

the forward side of the partition door in

conjunction with relocating the striker

defeat mechanism to the aft side. There

was no supportive reasoning provided

for this recommendation, although it

appears that the commenter believes

that in the event the door is blocked or

inoperable, it would be easier to

evacuate the forward section of the crew

rest area by removing the door from it’s

hinges than by defeating the striker

mechanism. As was previously stated,

the door design proposed by Boeing has

been reviewed by the FAA, and has

been found to provide an acceptable

means to prevent entrapment.

Another comment suggests that a

crash axe should be required in the

forward compartment as a backup to the

striker defeat mechanism. This

suggestion will not be added to these

special conditions. The partition door

proposed by Boeing has been designed

so that it cannot be jammed as a result

of aircraft structural failure. Even if the

door were jammed, it is possible to

defeat the striker mechanism to gain

access to the aft section of the crew rest

area. If for some reason it were not

possible to operate the striker defeat

mechanism, the occupants of the

forward section of the crew rest area

could still use the two-way voice

communication equipment required by

Item 13, paragraph f., to summon

additional help. Since this area is not

allowed to be occupied for taxi, takeoff,

and landing, there is no immediate need

to be able to evacuate to the main deck.

For this reason, the two-way voice

communication equipment is

considered an adequate backup to the

striker defeat mechanism.

A comment was also submitted

regarding the requirement for one

additional protective breathing

equipment (PBE) in the forward section

of the crew rest. Concern was expressed

that one additional PBE installed in the

forward section of the crew rest area

would not adequately protect all the

occupants. The PBE’s that are installed

in the forward and aft sections are

intended to be used for firefighting, not

for providing breathable air for each

crew rest occupant. There are no other

crew rest areas that require one PBE per

occupant. In the event of a fire in the

crew rest area, it would be expected that

one or two flight attendants would don

the protective breathing equipment and

stay to fight the fire while the others

quickly evacuated to the main deck. For

this reason, the one additional PBE in

the forward section provides the same

level of safety for a divided crew rest as

has been provided for the previously

certified open crew rest in that its

installation assures accessibility of the

emergency equipment deemed most

critical, within each section of the crew

rest area.

Another comment suggests that the

leg rests on the double seats located

directly aft of the partition door should

be required to be stowed when not in

use. For the Boeing 747–400 that was

reviewed by the AFA, instructional

placards have been installed that require

the legrests be stowed in accordance

with the commenter’s suggestion. It is

the FAA’s position that it is not

necessary to include this proposal in the

revised special conditions, as the

legrests do not affect the partition door

operation and can be quickly stowed by

anyone in the aft section of the crew rest

area. As a normal function of certifying

new crew rest configurations, this type

of a potential egress hindrance would be

evaluated and appropriate actions

would be taken to ensure the

effectiveness of the escape path.

Another comment from the AFA

relates a near-fire incident inside a 747–

400 crew rest where a blanket started

smoldering in a crew rest bunk after

having been in contact with a reading

light. The commenter requests that fire

retardant lights and materials be

required in this area. The types of

materials allowed in the overhead crew

rest area are already addressed as part

of the certification basis of the 747–400

which includes § 25.853, Amendment

59. In addition to the materials required
59564 Federal Register / Vol. 62, No. 213 / Tuesday, November 4, 1997 / Rules and Regulations

by § 25.853 Amendment 59, the crew

rest area is also protected by a smoke

detection system required by Item 10;

Item 13, paragraph c.; and Item 13,

paragraph f., that annunciates in the

flight deck, even when the crew rest

area is unoccupied. In regard to the

specific incident identified by the

commenter, Boeing has made design

changes to replace the style of reading

light involved in the near fire incident

with a reading light design that puts out

less heat.

One comment was received from the

Air Line Pilots Association, who states

that the location of the crew rest area

would make it unsuitable for cockpit

crews, but provided no supportive

reasoning for its position.

It is the FAA’s position that the

additional criteria contained in Item 13

of these special conditions provides an

equal level of safety for a divided crew

rest as that established by the

regulations incorporated by reference in

Type Certificate No. A20WE.

Under standard practice, the effective

date of final or amended special

conditions would be 30 days after the

date of publication in the Federal

Register. However, since delivery of

Model 747–400 airplanes with these

additional novel or unusual design

features is currently scheduled for

October 24, 1997, and because a delay

would significantly affect the

applicant’s installation and type

certification of the crew rest area, the

FAA finds that good cause exists for

making these amended special

conditions effective upon issuance.

Conclusion: This action affects only

certain novel or unusual design features

on one model series of airplanes. It is

not a rule of general applicability and

affects only the manufacturer who

applied to the FAA for approval of these

features on the airplane.

List of Subjects in 14 CFR Part 25

Air transportation, Aircraft, Aviation

safety, Safety.

The authority citation for these

special conditions is as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701,

44702, 44704.

The Amended Special Conditions

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the following amended

special conditions are issued as part of

the type certification basis for the

Boeing Model 747 series airplanes.

1. Occupancy of the overhead crew

rest area is limited to a maximum of 10

crewmembers. Occupancy during taxi,

takeoff, or landing is not permitted.

2. There must be a stairway between

the main deck and the crew rest area

and there must be an alternate

evacuation route for occupants of the

crew rest area.

The stairway and alternate evacuation

route must be located on opposite sides

of the crew rest area or have sufficient

separation within the compartment. The

stairway and the alternate evacuation

route must provide for evacuation of an

incapacitated person, with assistance,

from the crew rest area to the main

deck, must not be dependent on any

powered device, and must be designed

to minimize the possibility of blockage

which might result from fire,

mechanical or structural failure. The

crewmember procedures for carriage of

an incapacitated person must be

established.

3. An exit sign meeting the

requirements of § 25.812(b)(1)(i) must be

provided in the crew rest area near the

stairway.

4. In the event the airplane’s main

power system should fail, emergency

illumination of the crew rest area must

be automatically provided. Unless two

independent sources of normal lighting

are provided, the emergency

illumination of the crew rest area must

be automatically provided if the crew

rest area normal lighting system should

fail. The illumination level must be

sufficient for the occupants of the crew

rest area to locate, and descend to the

main deck by means of the stairway

and/or the alternate evacuation route,

and to read any required operating

instructions.

5. There must be a means for two-way

voice communication between

crewmembers on the flight deck and

occupants of the crew rest area, and

between crewmembers and at least one

flight attendant seat on the main deck

and occupants of the crew rest area.

6. There must also be either public

address speaker(s), or other means of

alerting the occupants of the crew rest

area to an emergency situation, installed

in the crew rest area.

7. There must be a means, readily

detectable by occupants of the crew rest

area, that indicates when seat belts

should be fastened and when smoking

is prohibited.

8. For each occupant permitted in the

crew rest area, there must be an

approved seat or berth that must be able

to withstand the maximum flight loads

when occupied.

9. The following equipment must be

provided:

a. At least one approved fire

extinguisher appropriate to the kinds of

fires likely to occur.

b. One protective breathing device,

having TSO–C99 authorization or

equivalent, suitable for firefighting.

c. One flashlight.

10. A smoke detection system that

annunciates in the flight deck and is

audible in the crew rest area must be

provided.

11. A supplemental oxygen system

equivalent to that provided for main

deck passengers must be provided for

each seat and berth.

12. There must be a limitation in the

Airplane Flight Manual or other suitable

means requiring that crewmembers be

trained in the use of the evacuation

routes.

13. The following requirements apply

to crew rest areas that are divided into

several sections by the installation of

curtains or partitions.

a. To compensate for lack of crowd

awareness, there must be an aural alert

that can be heard in each section of the

crew rest area that accompanies

automatic presentation of supplemental

oxygen masks in each section of the

crew rest area. The supplemental

oxygen masks are required in each

section whether or not seats or berths

are installed in each section. There must

also be a means by which the flightcrew

can manually deploy the oxygen masks.

b. A placard is required adjacent to

each curtain that visually divides or

separates the overhead crew rest area

into small areas to serve a function of

creating privacy. The placard must

require that the curtain(s) remain open

when the private area it creates is

unoccupied. The vestibule area adjacent

to the stairway is not considered a

private area and, as such, its vacancy

does not require a placard.

c. Each crew rest section created by

the installation of a curtain must meet

the requirements of items 4, 6, 7, and 10

of these special conditions with the

curtain open or closed.

d. Overhead crew rest areas, which

are visually divided to the extent that

evacuation could be affected, must have

exit signs meeting the requirements of

§ 25.812(b)(1)(i) in each separate area of

the crew rest area which direct

occupants to the primary stairway exit.

e. Sections within an overhead crew

rest area that are created by the

installation of a rigid partition with a

door physically separating the sections

must provide a secondary evacuation

route from each section of the crew rest

area to the main deck, or it must be

shown that any door between the

sections has been designed to preclude

anyone from being trapped inside the

compartment. Any door between the

sections must be shown to be openable

when crowded against. There can be no
Federal Register / Vol. 62, No. 213 / Tuesday, November 4, 1997 / Rules and Regulations 59565

more than one door between each

section of a crew rest area and the

primary stairway exit. Exit signs

meeting the requirements of

§ 25.812(b)(1)(i) that direct occupants to

the primary stairway exit must be

provided in each section of the crew rest

area.

f. Each smaller area, within the main

crew rest area, created by the

installation of a partition with a door

must individually meet the

requirements of items 4, 5, 6, 7, 9 and

10 of these special conditions with the

door open or closed. The requirements

of items 5 and 9 are not applicable to

lavatories or other small areas that are

not intended to be occupied for

extended periods of time.

Issued in Renton, Washington, on October

23, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service,

ANM–100.

[FR Doc. 97–29125 Filed 11–3–97; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–268–AD; Amendment

39–10190; AD 97–23–02]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 727–100 Series Airplanes

Modified in Accordance With

Supplemental Type Certificate (STC)

SA8472SW

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to certain Boeing Model 727–

100 series airplanes. This action

requires a revision to the Airplane

Flight Manual (AFM) to prohibit

stabilized operation between 60 and 75

percent N1 speed during ground

operations in reverse or forward thrust.

This amendment is prompted by a

report that, during preparation for

takeoff, a transport category airplane

equipped with Rolls-Royce Tay 650–15

engines sustained an engine fan blade

failure, followed by an engine fire. The

actions specified in this AD are

intended to prevent uncontained failure

of engine fan blades due to high cycle

fatigue cracking, which could result in

loss of thrust from the affected engine

and secondary damage to the airplane

and/or fire.

DATES: Effective November 19, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of November

19, 1997.

Comments for inclusion in the Rules

Docket must be received on or before

January 5, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 97–NM–

268–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

The Airplane Flight Manual (AFM)

Supplement referenced in this AD may

be obtained from the Dee Howard

Company, P.O. Box 469001, San

Antonio, Texas 78246. This information

may be examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at

the FAA, Rotorcraft Directorate, 2601

Meacham Boulevard, Fort Worth, Texas;

or at the Office of the Federal Register,

800 North Capitol Street, NW., suite

700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ron

Filler, Flight Test Pilot, Airplane

Certification Office, ASW–150, FAA,

Rotorcraft Directorate, 2601 Meacham

Boulevard, Fort Worth, Texas, 76137–

4298; telephone (817) 222–5132; fax

(817) 222–5960.

SUPPLEMENTARY INFORMATION: The

Rijksluchtvaartdienst (RLD), which is

the airworthiness authority for the

Netherlands, recently notified the FAA

that it received a report indicating that,

during preparation for takeoff, a Fokker

Model F28 Mark 0100 series airplane

equipped with Rolls-Royce Tay 650–15

engines sustained an engine fan blade

failure, followed by an engine fire.

Investigation revealed that five fan

blades failed at the root area, three fan

blades failed at mid-height, and the

remainder were damaged severely.

Further investigation revealed that all

five fan blades failed due to rapid high

cycle fatigue cracking with low cycle

fatigue cracking origin. Evidence of

rapid high cycle fatigue cracking

indicates that an operational effect is

causing high vibratory stresses. RollsRoyce considers that the high cycle

fatigue cracking was caused by vibration

during previous thrust reverser

applications.

Upon further investigation, the FAA

has determined that Boeing 727QF

airplanes have engine installation and

service records that are similar to

Fokker Model F28 Mark 0100 series

airplanes. Boeing 727QF airplanes are

Boeing Model 727–100 airplanes that

have been modified in accordance with

Supplemental Type Certificate (STC)

SA8472SW, which includes the

installation of Rolls-Royce Tay 651–54

engines.

The FAA has evaluated these findings

and has determined that high-cycle

fatigue cracking of the engine fan blades

could cause uncontained failure of the

engine fan blades. Such fatigue

cracking, if not corrected, could result

in loss of thrust from the affected engine

and secondary damage to the airplane

and/or fire.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Dee Howard Airplane Flight Manual

(AFM) Supplement CR102–F–066,

Change 19, dated October 2, 1997 (for

Boeing 727QF airplanes), which

prohibits stabilized operation between

60 and 75 percent N1 speed during

ground operations in reverse or forward

thrust. Accomplishment of the actions

specified in the service document is

intended to adequately address the

identified unsafe condition.

Explanation of the Requirements of the

Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other Boeing Model 727–100

series airplanes of this same type design

registered in the United States, this AD

is issued to require a revision to the

Limitations Section of the FAAapproved AFM to prohibit stabilized

operation between 60 and 75 percent N1

speed during ground operations in

reverse or forward thrust.

These actions are required to be

accomplished in accordance with the

document described previously.

Determination of Rule’s Effective Date

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 30 days.

Comments Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public comment, comments are

invited on this rule. Interested persons

are invited to comment on this rule by

submitting such written data, views, or

arguments as they may desire.