7924 Federal Register / Vol. 62, No. 35 / Friday, February 21, 1997 / Rules and Regulations

A preliminary hazard analysis must

be performed by the applicant, for

approval by the FAA, to identify

electrical and/or electronic systems that

perform critical functions. The term

‘‘critical’’ means those functions whose

failure would contribute to, or cause, a

failure condition that would prevent the

continued safe flight and landing of the

airplane. The systems identified by the

hazard analysis that perform critical

functions are candidates for the

application of HIRF requirements. A

system may perform both critical and

non-critical functions. Primary

electronic flight display systems, and

their associated components, perform

critical functions such as attitude,

altitude, and airspeed indication. The

HIRF requirements apply only to critical

functions.

Compliance with HIRF requirements

may be demonstrated by tests, analysis,

models, similarity with existing

systems, or any combination of these.

Service experience alone is not

acceptable since normal flight

operations may not include an exposure

to the HIRF environment. Reliance on a

system with similar design features for

redundancy as a means of protection

against the effects of external HIRF is

generally insufficient since all elements

of a redundant system are likely to be

exposed to the fields concurrently.

Conclusion

In view of the design features

discussed for the Beechcraft Model E90

Airplane, the following special

conditions are issued. This action is not

a rule of general applicability and

affects only those applicants who apply

to the FAA for approval of these features

on these airplanes.

The substance of these special

conditions has been subject to the notice

and public comment procedure in

several prior rulemaking actions. For

example, the Dornier 228–200 (53 FR

14782, April 26, 1988), the Cessna

Model 525 (56 FR 49396, September 30,

1991), and the Beech Model 200, A200,

and B200 airplanes (57 FR 1220, January

13, 1992). It is unlikely that additional

public comment would result in any

significant change from those special

conditions already issued and

commented on. For these reasons, and

because a delay would significantly

affect the applicant’s installation of the

system and certification of the airplane,

which is imminent, the FAA has

determined that prior public notice and

comment are unnecessary and

impracticable, and good cause exists for

adopting these special conditions

without notice. Therefore, these special

conditions are being made effective

upon publication in the Federal

Register. However, as previously

indicated, interested persons are invited

to comment on these special conditions

if they so desire.

List of Subjects in 14 CFR Part 23

Aircraft, Aviation safety, Signs and

symbols.

Citation

The authority citation for these

special conditions is as follows:

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

44702, and 44704; 14 CFR 21.16 and 21.101;

and 14 CFR 11.28 and 11.49

Adoption of Special Conditions

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the following special

conditions are issued as part of the type

certification basis for the modified

Beechcraft Model E90 airplane:

1. Protection of Electrical and

Electronic Systems from High Intensity

Radiated Fields (HIRF). Each system

that performs critical functions must be

designed and installed to ensure that the

operations, and operational capabilities

of these systems to perform critical

functions, are not adversely affected

when the airplane is exposed to high

intensity radiated electromagnetic fields

external to the airplane.

2. For the purpose of these special

conditions, the following definition

applies: Critical Functions: Functions

whose failure would contribute to, or

cause, a failure condition that would

prevent the continued safe flight and

landing of the airplane.

Issued in Kansas City, Missouri on

February 7, 1997.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft

Certification Service.

[FR Doc. 97–4354 Filed 2–20–97; 8:45 am]

BILLING CODE 4910–13–P

14 CFR Part 39

[Docket No. 96–NM–32–AD; Amendment

39–9932; AD 97–04–08]

RIN 2120–AA64

Airworthiness Directives; Fokker

Model F27 Mark 050, 100, 200, 300, 400,

600, and 700 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain Fokker Model F27

Mark 050, 100, 200, 300, 400, 600, and

700 series airplanes, that requires an

ultrasonic inspection to determine if

certain tubes are installed in the drag

stay units of the main landing gear

(MLG), and various follow-on actions.

This amendment is prompted by a

report that, due to fatigue cracking from

an improperly machined radius of the

inner tube, a drag stay broke, and,

consequently, lead to the collapse of the

MLG during landing. The actions

specified by this AD are intended to

prevent such fatigue cracking, which

could result in reduced structural

integrity or collapse of the MLG.

DATES: Effective March 28, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of March 28,

1997.

ADDRESSES: The service information

referenced in this AD may be obtained

from Fokker Services B.V., Technical

Support Department, P.O. Box 75047,

1117 ZN Schiphol Airport, The

Netherlands. 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:

Ruth Harder, Aerospace

Engineer,Standardization Branch,

ANM–113, FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056;

telephone (206) 227–1721; fax (206)

227–1149.

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 Fokker

Model F27 Mark 050, 100, 200, 300,

400, 600, and 700 series airplanes was

published in the Federal Register on

October 31, 1996 (61 FR 56170). That

action proposed to require an ultrasonic

inspection to determine if certain tubes

are installed on the DSUs of the MLG,

and various follow-on actions.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. No

comments were submitted in response

to the proposal or the FAA’s

determination of the cost to the public.

Conclusion

The FAA has determined that air

safety and the public interest require the

adoption of the rule as proposed.
Federal Register / Vol. 62, No. 35 / Friday, February 21, 1997 / Rules and Regulations 7925

Cost Impact

The FAA estimates that 10 Model F27

Mark 050, 100, 200, 300, 400, 600, and

700 series airplanes of U.S. registry will

be affected by this AD, that it will take

approximately 2 work hours per

airplane to accomplish the required

inspection, at an average labor rate of

$60 per work hour. Based on these

figures, the cost impact of the inspection

required by this AD on U.S. operators is

estimated to be $1,200, or $120 per

airplane. This cost impact figure is

based on assumptions that no operator

has yet accomplished any of the

requirements of this AD action, and that

no operator would accomplish those

actions in the future if this AD were not

adopted.

There currently are no Fokker Model

F27 Mark 050 series airplanes on the

U.S. Register that will require the

inspection of the DSU. The only

airplanes that will require this

inspection are currently operated by

non-U.S. operators under foreign

registry; therefore, they are not directly

affected by this AD action. However, the

FAA considers that inclusion of these

airplanes in the applicability of this rule

is necessary to ensure that the unsafe

condition is addressed in the event that

any of these airplanes are imported and

placed on the U.S. Register in the future.

Regulatory Impact

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. 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

97–04–08 Fokker: Amendment 39–9932.

Docket 96–NM–32–AD.

Applicability: Model F27 Mark 050, 100,

200, 300, 400, 600, and 700 series airplanes,

equipped with Dowty Aerospace main

landing gear (MLG) drag stay units (DSU)

having part number (P/N) 200684001,

200261001, or 200485001; 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 as indicated, unless

accomplished previously.

To prevent fatigue cracking in drag stay

unit of the MLG, which could result in

reduced structural integrity or collapse of the

MLG, accomplish the following:

(a) Within 60 days after the effective date

of this AD, perform an ultrasonic inspection

to determine if a tube having part number (P/

N) 200485300 with a straight bore, or a tube

having P/N 200259300 with a change in

section (stepped bore), is installed on the

DSU’s of the MLG, in accordance with

Fokker Service Bulletin F27/32–167, dated

November 19, 1993 (for Model F27 Mark 100,

200, 300, 400, 600, and 700 series airplanes),

or Fokker Service Bulletin SBF50–32–029,

dated February 11, 1994 (for Model F27 Mark

050 series airplanes), as applicable.

Note 2: Fokker Service Bulletin F27/32–

167 references Dowty Service Bulletins 23–

169B and 32–82W; and Fokker Service

Bulletin SBF50–32–029 references Dowty

Service Bulletin F50–32–50; as additional

sources of service information for procedures

to accomplish the actions specified in this

AD.

(b) For all airplanes: If any tube having P/

N 200485300 with a straight bore is found

installed during the inspection required by

paragraph (a) of this AD, prior to further

flight, reidentify it in accordance with Fokker

Service Bulletin F27/32–167, dated

November 19, 1993 (for Model F27 Mark 100,

200, 300, 400, 600, and 700 series airplanes);

or Fokker Service Bulletin SBF50–32–029,

dated February 11, 1994 (for Model F27 Mark

050 series airplanes); as applicable.

(c) For Model F27 Mark 50 series airplanes:

If any tube having P/N 200259300 with a

change in section (stepped bore) is found

installed during the inspection required by

paragraph (a) of this AD, prior to further

flight, replace the DSU with a new or

serviceable DSU having P/N 200684004, in

accordance with Fokker Service Bulletin

SBF50–32–029, dated February 11, 1994.

(d) For F27 Mark 100, 200, 300, 400, 600,

and 700 series airplanes: If any tube having

P/N 200259300 with a change in section

(stepped bore) is found installed during the

inspection required by paragraph (a) of this

AD, prior to further flight, re-identify the

DSU in accordance with Fokker Service

Bulletin F27/32–167, dated November 19,

1993. Following accomplishment of the reidentification, prior to further flight, perform

an ultrasonic inspection to detect cracks in

the re-identified DSU’s, in accordance with

that service bulletin.

(1) For airplanes equipped with any DSU

re-identified as P/N 200684003, 200261003,

or 200485003: If no crack is detected, no

further action is required by this AD.

(2) For airplanes equipped with any DSU

re-identified as P/N 200684002, 200261002,

or 200485002: If no crack is detected,

accomplish paragraphs (c)(2)(i) and (c)(2)(ii)

of this AD.

(i) Repeat the ultrasonic inspection

required by paragraph (d) of this AD

thereafter at intervals not to exceed 1,500

flight cycles.

(ii) At the next MLG overhaul, but no later

than 12,000 flight cycles after the effective

date of this AD, rework and re-identify the

DSU again, or replace the DSU with a reidentified DSU, in accordance with the

service bulletin. Accomplishment of the

rework and re-identification, or replacement

constitutes terminating action for the

repetitive inspection requirements of this

AD.

(3) If any crack signal indication of any

DSU tube is greater than or equal to 80

percent, prior to further flight, replace the

DSU with a re-identified DSU, in accordance

with the service bulletin.

(4) If any crack signal indication of any

DSU tube is greater than or equal to 1 percent

but less than 80 percent, accomplish

paragraphs (d)(4)(i) and (d)(4)(ii) of this AD.

(i) Repeat the ultrasonic inspection

required by paragraph (d) of this AD

thereafter at intervals not to exceed 1,500

flight cycles.

(ii) At the next MLG overhaul, but no later

than 12,000 flight cycles after the effective
7926 Federal Register / Vol. 62, No. 35 / Friday, February 21, 1997 / Rules and Regulations

date of this AD, replace the DSU with a reidentified DSU, in accordance with the

service bulletin. Accomplishment of the

replacement constitutes terminating action

for the repetitive inspection requirements of

this AD.

(e) 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, Manager,

Standardization Branch, ANM–113, 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, Standardization

Branch, ANM–113.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Standardization Branch,

ANM–113.

(f) 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.

(g) The actions shall be done in accordance

with Fokker Service Bulletin F27/32–167,

dated November 19, 1993; or Fokker Service

Bulletin SBF50–32–029, dated February 11,

1994; as applicable. 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 Fokker Services B.V.,

Technical Support Department, P.O. Box

75047, 1117 ZN Schiphol Airport, The

Netherlands. 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.

(h) This amendment becomes effective on

March 28, 1997.

Issued in Renton, Washington, on February

7, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–3695 Filed 2–20–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 96–NM–65–AD; Amendment

39–9931; AD 97–04–07]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A300–600 and A310 Series Airplanes

Equipped with Pre-Modification

5844D4829 Rudders

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to certain Airbus Model

A300–600 and A310 series airplanes,

that currently requires repetitive visual

inspections and tap tests of the rudder

skin panels to detect disbonding; and

repairs, if necessary. That AD was

prompted by reports of weakening of the

bonding material between the core of

the rudder and its inner and outer skin,

and cracking of the core. This

amendment adds repetitive elasticity

laminate checker (ELCH) inspections of

the rudder in place of the currently

required tap tests. It also requires

replacement of the rudder with a

modified rudder, which will terminate

the repetitive inspections. The actions

specified by this AD are intended to

detect and prevent disbonding of the

rudder, which, if not corrected, could

reduce the structural integrity of the

rudder, and consequently lead to a

reduction in its ability to sustain limit

loads.

DATES: Effective March 28, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of March 28,

1997.

ADDRESSES: The service information

referenced in this AD may be obtained

from Airbus Industrie, 1 Rond Point

Maurice Bellonte, 31707 Blagnac Cedex,

France. 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: Tim

Backman, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(206) 227–2797; fax (206) 227–1149.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39)

by superseding AD 90–12–13,

amendment 39–6625 (55 FR 23190, June

7, 1990), which is applicable to certain

Airbus Model A300-600 and A310 series

airplanes, was published in the Federal

Register on October 23, 1996 (61 FR

54955). The action proposed to continue

to require repetitive visual inspections

and tap tests of the rudder skin panels

to detect disbonding; and repairs, if

necessary. It also proposed to add

repetitive elasticity laminate checker

(ELCH) inspections of the rudder in

place of the currently required tap tests.

It also proposed to replacement of the

rudder with a modified rudder, which

would terminate the repetitive

inspections.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Support for the Proposal

One commenter supports the

proposed AD.

Request To Withdraw the Proposal

Two commenters request that the

FAA withdraw the proposed action.

These commenters point out that a

retrofit campaign was completed in

1993 on all affected airplanes that were

equipped with the pre-modification

5844 rudders. In effect, that campaign

installed the proposed terminating

action on all airplanes. In light of this,

these commenters contend that the

proposed AD is not necessary.

The FAA does not concur with the

commenters’ request to withdraw this

AD action. The FAA has no evidence

that all affected airplanes, worldwide,

have been modified with the new

rudder. This AD will ensure that any

affected airplane that is imported and

placed on the U.S. Register in the future,

or any airplane that is currenly not

operating (i.e., is stored) and not

equipped with the new rudder, will be

inspected and modified in accordance

with this AD prior to entering service.

Request To Correct Service Bulletin

Information

Two commenters point out an error in

paragraph (d) of the proposal

concerning the appropriate source of

service information relative to the ELCH

inspections required on Model A310

series airplanes. The proposal indicates

that the service bulletin number is

A310–55–2008; however, the correct

number is A310–55–2010.

The FAA acknowledges that

typographical error in proposed

paragraph (d). The correct service

bulletin number was discussed in the

preamble to the notice and appeared

correctly in all other references to it in

the proposed AD. Paragraph (d) of the

final rule has been revised to reflect the

correct service bulletin number as

A310–55–2010.

Conclusion

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 change

previously described. The FAA has

determined that this change will neither

increase the economic burden on any