3042 Federal Register / Vol. 72, No. 15 / Wednesday, January 24, 2007 / Rules and Regulations 

Frequency 

Field strength 

(volts per meter) 

Peak Average 

10 kHz–100 kHz ........... 50 50 

100 kHz–500 kHz ......... 50 50 

500 kHz–2 MHz ............ 50 50 

2 MHz–30 MHz ............. 100 100 

30 MHz–70 MHz ........... 50 50 

70 MHz–100 MHz ......... 50 50 

100 MHz–200 MHz ....... 100 100 

200 MHz–400 MHz ....... 100 100 

400 MHz–700 MHz ....... 700 50 

700 MHz–1 GHz ........... 700 100 

1 GHz–2 GHz ............... 2000 200 

2 GHz–4 GHz ............... 3000 200 

4 GHz–6 GHz ............... 3000 200 

6 GHz–8 GHz ............... 1000 200 

8 GHz–12 GHz ............. 3000 300 

12 GHz–18 GHz ........... 2000 200 

18 GHz–40 GHz ........... 600 200 

The field strengths are expressed in terms 

of peak root-mean-square (rms) values. 

or, 

(2) The applicant may demonstrate by 

a system test and analysis that the 

electrical and electronic systems that 

perform critical functions can withstand 

a minimum threat of 100 volts per 

meter, electrical field strength, from 10 

kHz to 18 GHz. When using this test to 

show compliance with the HIRF 

requirements, no credit is given for 

signal attenuation due to installation. 

A preliminary hazard analysis must 

be performed by the applicant, for 

approval by the FAA, to identify either 

electrical 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. 

Applicability 

As discussed above, these special 

conditions are applicable to the Piper 

PA–32R–301T and PA–32–301FT. 

Should Piper Aircraft, Inc. apply at a 

later date for a supplemental type 

certificate for a type design change to 

modify any other model on the same 

type certificate to incorporate the same 

novel or unusual design feature, the 

special conditions would apply to that 

model as well under the provisions of 

§ 21.101. 

Conclusion 

This action affects only certain novel 

or unusual design features on one model 

of airplane. It is not a rule of general 

applicability and affects only the 

applicant who applied to the FAA for 

approval of these features on the 

airplane. 

The substance of these special 

conditions has been subjected to the 

notice and comment period in several 

prior instances and has been derived 

without substantive change from those 

previously issued. It is unlikely that 

prior public comment would result in a 

significant change from the substance 

contained herein. For this reason, and 

because a delay would significantly 

affect the 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 upon 

issuance. The FAA is requesting 

comments to allow interested persons to 

submit views that may not have been 

submitted in response to the prior 

opportunities for comment described 

above. 

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 and 

44701; 14 CFR 21.16 and 21.101; and 14 CFR 

11.38 and 11.19. 

The 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 Piper PA–32R–301T, 

Saratoga II TC, and PA–32–301FT, Piper 

6X, airplane modified by Piper Aircraft, 

Inc. to add a G1000 EFIS system. 

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 January 

12, 2007. 

Kim Smith, 

Manager, Small Airplane Directorate, Aircraft 

Certification Service. 

[FR Doc. E7–1018 Filed 1–23–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 33 

[Docket No. NE127; Special Conditions No. 

33–006–SC] 

Special Conditions: General Electric 

Company GEnx Model Turbofan 

Engines 

AGENCY: Federal Aviation 

Administration, DOT. 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for the General Electric Company 

(GE) GEnx turbofan engine models 

GEnx–1B54, GEnx–1B58, GEnx–1B64, 

GEnx–1B67, GEnx–1B70, GEnx–1B70/ 

72, GEnx–1B70/75, GEnx–1B72, and 

GEnx–1B75. The fan blades of these 

engines will have novel or unusual 

design features when compared to the 

state of technology envisioned in the 

part 33 airworthiness standards. The 

applicable airworthiness regulations do 

not contain adequate or appropriate 

safety standards for these design 

features. These special conditions 

contain the added safety standards that 

the Administrator considers necessary 

to establish a level of safety equivalent 

to that established by the existing 

airworthiness standards. 

DATES: Effective Date: The effective date 

of these special conditions is January 

12, 2007. 

FOR FURTHER INFORMATION CONTACT: 

Robert McCabe, ANE–111, Rulemaking 

and Policy Branch, Engine and Propeller 

Directorate Standards Staff, Aircraft 

Certification Service, 12 New England 


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Federal Register / Vol. 72, No. 15 / Wednesday, January 24, 2007 / Rules and Regulations 3043 

Executive Park, Burlington, 

Massachusetts 01803–5299; telephone 

(781) 238–7138; facsimile (781) 238–

7199; e-mail robert.mccabe@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

On December 13, 2004, the General 

Electric Company (GE) applied to the 

FAA for a new type certificate for the 

GEnx series engine models. On May 24, 

2005, GE submitted a revised 

application for a type certificate that 

added models and changed the model 

designation nomenclature. The turbofan 

engine models to be certified are GEnx–

1B54, GEnx–1B58, GEnx–1B64, GEnx–

1B67, GEnx–1B70, GEnx–1B70/72, 

GEnx–1B70/75, GEnx–1B72, and GEnx–

1B75. For these GEnx engine models, 

GE plans to use carbon graphite 

composite fan blades incorporating 

metal leading and trailing edges that use 

geometry, composite structural 

materials, and manufacturing methods 

very similar to those used for previously 

certified GE90–series engine fan blade 

designs. 

In lieu of direct compliance to 14 CFR 

section (§ ) 33.94(a)(1) for the GEnx fan 

blades, the FAA proposed that GE 

comply with new special conditions 

that retain the basic requirements of the 

original SC–33–ANE–08 created for the 

GE90–76B, –77B, –85B , –90B, –94B 

model certification program, and then 

successfully applied to the GE90–

110B1, –113B, and –115B model 

certification program. 

These GE90 series engine model fan 

blades are manufactured using carbon 

graphite composite material that also 

incorporates metal leading and trailing 

edges. These unusual and novel design 

features result in the fan blades having 

significant differences in material 

property characteristics when compared 

to conventionally designed fan blades 

using non-composite metallic materials. 

GE submitted data and analysis during 

the GE90–76B, –77B, –85B, –90B, –94B 

model certification program showing 

the likelihood that a composite fan 

blade will fail below the inner annulus 

flow path line is highly improbable. GE, 

therefore, questioned the 

appropriateness of the requirement 

contained in § 33.94(a)(1) to show blade 

containment after a failure of the blade 

at the outermost retention feature. 

The FAA determined that the 

requirements of § 33.94(a)(1) are based 

on metallic blade characteristics and 

service history and were not appropriate 

for the unusual design features of the 

composite fan blade design planned for 

the GE90–76B, –77B, –85B, –90B, –94B 

model turbofan engines. The FAA 

determined that a more realistic blade 

retention test would be achieved with a 

fan blade failure at the inner annulus 

flow path line (the complete airfoil 

only) instead of the outermost blade 

retention feature as currently required 

by § 33.94(a)(1). 

The FAA, therefore, issued special 

conditions SC–33–ANE–08 on February 

1, 1995 for the GE90–76B, –77B, –85B, 

–90B, –94B engine models. These 

special conditions defined additional 

safety standards for the carbon graphite 

composite fan blades that were 

appropriate for the unusual design 

features of those fan blades, and that 

were determined to be necessary to 

establish a level of safety equivalent to 

that established by the intent of the 

airworthiness standards of § 33.94(a)(1). 

The FAA later determined that these 

special conditions continued to be 

appropriate for the amended type 

certificate applied to the GE90–110B1, 

–113B, and –115B engine models. The 

FAA has also concluded that these same 

special conditions, with some 

additional enhancements, continue to 

be appropriate for the GEnx model 

engines. 

Type Certification Basis 

Under the provisions of 14 CFR 21.17, 

GE must show that the GEnx series 

turbofan engine models meet the 

requirements of applicable provisions of 

part 33 in effect on the date of the 

application for the type certificate. The 

FAA has determined that the applicable 

airworthiness regulations in part 33 do 

not contain adequate or appropriate 

safety standards for the GEnx series 

turbofan engine models because of its 

novel and unusual fan blade design 

features. Therefore, these special 

conditions are prescribed under the 

provisions of 14 CFR 11.19 and 21.16, 

and will become part of the type 

certification basis for GEnx engine in 

accordance with § 21.17(a)(2). 

As discussed above, these special 

conditions apply only to the GEnx series 

turbofan engine models GEnx–1B54, 

GEnx–1B58, GEnx–1B64, GEnx–1B67, 

GEnx–1B70, GEnx–1B70/72, GEnx–

1B70/75, GEnx–1B72, and GEnx–1B75. 

If the type certificate for those models 

is amended later to include any other 

models that incorporate the same novel 

or unusual fan blade design features, 

these special conditions would apply to 

the other models under the provisions 

of § 21.101(a)(1). 

Discussion of Novel or Unusual Design 

Features 

The GEnx–1B54, –B58, –1B64, –1B67, 

–70B, –1B70/72, –1B70/75, –72B and 

–75B engine models will incorporate fan 

blades to be manufactured using carbon 

graphite composite material that 

incorporates metal leading and trailing 

edges. The FAA has conducted that 

these carbon graphite composite fan 

blades are novel and unusual compared 

to the metallic fan blade technology 

envisioned in the part 33 standards and 

thus warrant these special conditions. 

The FAA has also determined that the 

composite fan blade design and 

construction presents factors other than 

the expected location of a blade failure 

that must be considered. Tests and 

analyses must account for the effects of 

in-service deterioration of, 

manufacturing and materials variations 

in, and environmental effects on, the 

composite material. Tests and analyses 

must also show that a lightning strike on 

a composite fan blade will not result in 

a hazardous condition to the aircraft and 

that the engine will continue to meet the 

requirements of § 33.75. 

Therefore, due to the close similarity 

of the GEnx models series fan blade 

design to the previously certified GE90 

model series fan blade design, the FAA 

is issuing similar special conditions as 

part of the type certification basis for the 

GEnx engine models in lieu of direct 

compliance to § 33.94(a)(1). These 

special conditions define the additional 

requirements that the Administrator 

considers necessary to establish a level 

of safety equivalent to that which would 

be established by direct compliance to 

the airworthiness standards of 

§ 33.94(a)(1). 

Discussion of Comments 

Notice of Proposed Special 

Conditions, Docket No. NE127; Notice 

No. 33–06–01–SC, was published in the 

Federal Register on November 17, 2006 

(71 FR 66888). We received no 

comments on the proposed special 

conditions. After a careful review of the 

applicable data, the FAA has 

determined that air safety and the 

public interest require the adoption of 

these special conditions as proposed. 

Conclusion 

This action affects only the carbon 

fiber composite fan blade design 

features on the GEnx series turbofan 

engine models GEnx–1B54, GEnx–1B58, 

GEnx–1B64, GEnx–1B67, GEnx–1B70, 

GEnx–1B70/72, GEnx–1B70/75, GEnx–

1B72, and GEnx–1B75. It is not a rule 

of general applicability, and it affects 

only the General Electric Company 

which has applied to the FAA for 

certification of these fan blade design 

features. 

List of Subjects in 14 CFR Part 33 

Air transportation, Aircraft, Aviation 

safety, Safety. 


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3044 Federal Register / Vol. 72, No. 15 / Wednesday, January 24, 2007 / Rules and Regulations 

The authority citation for these 

special conditions continues to read as 

follows: 

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

1423; 49 U.S.C. 106(g); and 14 CFR 11.49 and 

21.16. 

The Special Conditions 

Accordingly, the Federal Aviation 

Administration (FAA) issues the 

following special conditions as part of 

the type certification basis for the GEnx 

series turbofan engines. 

1. In lieu of the fan blade containment 

test with the fan blade failing at the 

outermost retention groove as specified 

in § 33.94(a)(1), complete the following 

requirements: 

(a) Conduct an engine fan blade 

containment test with the fan blade 

failing at the inner annulus flow path 

line. 

(b) Substantiate by test and analysis, 

or other methods acceptable to the 

Administrator, that a minimum material 

properties fan disk and fan blade 

retention system can withstand without 

failure a centrifugal load equal to two 

times the maximum load which the 

retention system could experience 

within approved engine operating 

limitations. The fan blade retention 

system includes the portion of the fan 

blade from the inner annulus flow path 

line inward to the blade dovetail, the 

blade retention components, and the fan 

disk and fan blade attachment features. 

(c) Using a procedure approved by the 

Administrator, establish an operating 

limitation that specifies the maximum 

allowable number of start-stop stress 

cycles for the fan blade retention 

system. The life evaluation shall include 

the combined effects of high cycle and 

low cycle fatigue. If the operating 

limitation is less than 100,000 cycles, 

that limitation must be specified in 

Chapter 5 of the Engine Manual 

Airworthiness Limitation Section. 

(d) Substantiate that, during the 

service life of the engine, the total 

probability of the occurrence of a 

hazardous engine effect defined in 

§ 33.75 due to an individual blade 

retention system failure resulting from 

all possible causes will be extremely 

improbable, with a cumulative 

calculated probability of failure of less 

than 10¥9 per engine flight hour. 

(e) Substantiate by test or analysis that 

not only will the engine continue to 

meet the requirements of § 33.75 

following a lightning strike on the 

composite fan blade structure, but that 

the lightning strike will also not cause 

damage to the fan blades that would 

prevent continued safe operation of the 

affected engine. 

(f) Account for the effects of in-service 

deterioration, manufacturing variations, 

minimum material properties, and 

environmental effects during the tests 

and analyses required by paragraphs (a), 

(b), (c), (d), and (e) of these special 

conditions. 

(g) Propose fleet leader monitoring 

and field sampling programs for the 

GEnx engine fan blades that will 

monitor the effects of usage on fan blade 

and retention system integrity. The 

sampling program should use the 

experience gained on current GE90 

engine model monitoring programs, and 

must be approved by the FAA prior to 

certification of the GEnx engine models. 

Issued in Burlington, Massachusetts, on 

January 12, 2007. 

Francis A. Favara, 

Manager, Engine and Propeller Directorate, 

Aircraft Certification Service. 

[FR Doc. 07–301 Filed 1–23–07; 8:45 am] 

BILLING CODE 4910–13–M 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. 2001–NM–183–AD; Amendment 

39–14889; AD 2007–02–02] 

RIN 2120–AA64 

Airworthiness Directives; McDonnell 

Douglas Model DC–8–55, DC–8F–54, 

and DC–8F–55 Airplanes; and Model 

DC–8–60, DC–8–70, DC–8–60F, and 

DC–8–70F Series Airplanes 

AGENCY: Federal Aviation 

Administration, DOT. 

ACTION: Final rule. 

SUMMARY: This amendment adopts a 

new airworthiness directive (AD), 

applicable to certain McDonnell 

Douglas Model DC–8 airplanes. This AD 

requires a one-time inspection for 

previous repairs of the aft fuselage skin 

panel at the longeron 28 skin splice; 

repetitive inspections for cracks of the 

same area; and related investigative and 

corrective actions. This AD also 

provides optional actions for extending 

the repetitive inspection intervals. The 

actions specified by this AD are 

intended to detect and correct cracks in 

the aft fuselage skin at the longeron 28 

skin splice, which could lead to loss of 

structural integrity of the aft fuselage, 

resulting in rapid decompression of the 

airplane. This action is intended to 

address the identified unsafe condition. 

DATES: Effective February 28, 2007. 

The incorporation by reference of 

certain publications listed in the 

regulations is approved by the Director 

of the Federal Register as of February 

28, 2007. 

ADDRESSES: The service information 

referenced in this AD may be obtained 

from Boeing Commercial Airplanes, 

Long Beach Division, 3855 Lakewood 

Boulevard, Long Beach, California 

90846, Attention: Data and Service 

Management, Dept. C1–L5A (D800–

0024). 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 FAA, Los Angeles 

Aircraft Certification Office, 3960 

Paramount Boulevard, Lakewood, 

California. 

FOR FURTHER INFORMATION CONTACT: Jon 

Mowery, Aerospace Engineer, Airframe 

Branch, ANM–120L, FAA, Los Angeles 

Aircraft Certification Office, 3960 

Paramount Boulevard, Lakewood, 

California 90712–4137; telephone (562) 

627–5322; fax (562) 627–5210. 

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 McDonnell 

Douglas Model DC–8–55, DC–8F–54, 

and DC–8F–55 airplanes; and Model 

DC–8–60, DC–8–70, DC–8–60F, and 

DC–8–70F series airplanes; was 

published as a supplemental notice of 

proposed rulemaking (NPRM) in the 

Federal Register on July 25, 2006 (71 FR 

42062). That action proposed to require 

a one-time inspection for previous 

repairs of the aft fuselage skin panel at 

the longeron 28 skin splice; repetitive 

inspections for cracks of the same area; 

related investigative and corrective 

actions; and reporting inspection 

findings to the manufacturer. That 

action also proposed to provide optional 

actions for extending the repetitive 

inspection intervals. 

Comments 

Interested persons have been afforded 

an opportunity to participate in the 

making of this amendment. Due 

consideration has been given to the 

comments received. 

Request To Lengthen Inspection 

Threshold for Certain Airplanes 

Air Transport Association (ATA), on 

behalf of one of its members, UPS, does 

not agree with the inspection threshold 

of 12 months for airplanes that have 

accumulated 24,000 total flight cycles or 

more as of the effective date of the AD, 

as specified in paragraph (a)(2) of the 

supplemental NPRM. The commenters 

note that all U.S.-registered McDonnell 


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