Federal Register / Vol. 74, No. 154 / Wednesday, August 12, 2009 / Rules and Regulations 40479 

Federal Register on July 7, 2009. It has 

come to the attention of the FDIC that 

the July 20 re-publication failed to 

include one further correction. This 

publication will rectify that oversight. 

The correction included in this 

Federal Register document corrects an 

error in the prior publication which 

caused an apparent inconsistency in the 

effective date. 

In the the final rule, FR Doc. No. 

2009–17009 published on July 20, 2009 

(74 FR 35726), make the following 

correction: 

On page 35744, the first sentence of 

the V. Effective and Compliance Dates 

section is corrected to read: 

Except as noted below, the final rule 

is effective August 6, 2009. 

Federal Deposit Insurance Corporation. 

Valerie J. Best, 

Assistant Executive Secretary. 

[FR Doc. E9–19259 Filed 8–11–09; 8:45 am] 

BILLING CODE 6714–01–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. NM400; Special Conditions No. 

25–388–SC] 

Special Conditions: Boeing Model 747– 

8/–8F Airplanes; Interaction of 

Systems and Structures 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for the Boeing Model 747–8/–8F 

airplanes. These airplanes will have a 

novel or unusual design feature(s) that 

will affect structural performance. The 

applicable airworthiness regulations do 

not contain adequate or appropriate 

safety standards for this design feature. 

These special conditions contain the 

additional 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: September 11, 

2009. 

FOR FURTHER INFORMATION CONTACT: 

Mark Freisthler, FAA, Airframe & Cabin 

Safety Branch, ANM–115, Transport 

Airplane Directorate, Aircraft 

Certification Service, 1601 Lind 

Avenue, SW., Renton, Washington 

98057–3356; telephone (425) 227–1119; 

facsimile (425) 227–1149. 

SUPPLEMENTARY INFORMATION: 

Background 

On November 4, 2005, The Boeing 

Company, PO Box 3707, Seattle, WA 

98124, applied for an amendment to 

Type Certificate Number A20WE to 

include the new Model 747–8 passenger 

airplane and the new Model 747–8F 

freighter airplane. The Model 747–8 and 

the Model 747–8F are derivatives of the 

747–400 and the 747–400F, 

respectively. Both the Model 747–8 and 

the Model 747–8F are four-engine jet 

transport airplanes that will have a 

maximum takeoff weight of 970,000 

pounds and new General Electric GEnx– 

2B67 engines. The Model 747–8 will 

have two flight crew and the capacity to 

carry 660 passengers. The Model 747– 

8F will have two flight crew and a zero 

passenger capacity, although Boeing has 

submitted a petition for exemption to 

allow the carriage of supernumeraries. 

Type Certification Basis 

Under the provisions of Title 14 Code 

of Federal Regulations (14 CFR) 21.101, 

Boeing must show that the Model 747– 

8 and 747–8F airplanes (hereafter 

referred to as the 747–8/–8F) as 

changed, continue to meet the 

applicable provisions of 14 CFR part 25, 

as amended by Amendments 25–1 

through 25–117, except for earlier 

amendments as agreed upon by the 

FAA. These regulations will be 

incorporated into Type Certificate No. 

A20WE after type certification approval 

of the 747–8/–8F. 

If the Administrator finds that the 

applicable airworthiness regulations 

(i.e., part 25) do not contain adequate or 

appropriate safety standards for the 

747–8/–8F because of a novel or 

unusual design feature, special 

conditions are prescribed under the 

provisions of § 21.16. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the 747–8/–8F must comply 

with the fuel vent and exhaust emission 

requirements of 14 CFR part 34 and the 

noise certification requirements of 14 

CFR part 36. 

Special conditions, as defined in 

§ 11.19, are issued under § 11.38, and 

become part of the type certification 

basis under § 21.101. 

Special conditions are initially 

applicable to the model for which they 

are issued. Should the type certificate 

for that model be amended later to 

include any other model that 

incorporates the same novel or unusual 

design feature, or should any other 

model already included on the same 

type certificate be modified to 

incorporate the same novel or unusual 

design feature, the special conditions 

would also apply to the other model 

under § 21.101. 

Novel or Unusual Design Features 

The Boeing Model 747–8/–8F is 

equipped with systems that affect the 

airplane’s structural performance, either 

directly or as a result of failure or 

malfunction. That is, the airplane’s 

systems affect how it responds in 

maneuver and gust conditions, and 

thereby affect its structural capability. 

These systems may also affect the 

aeroelastic stability of the airplane. 

Such systems represent a novel and 

unusual feature when compared to the 

technology envisioned in the current 

airworthiness standards. A special 

condition is needed to require 

consideration of the effects of systems 

on the structural capability and 

aeroelastic stability of the airplane, both 

in the normal and in the failed state. 

These special conditions require that 

the airplane meet the structural 

requirements of subparts C and D of 14 

CFR part 25 when the airplane systems 

are fully operative. These special 

conditions also require that the airplane 

meet these requirements considering 

failure conditions. In some cases, 

reduced margins are allowed for failure 

conditions based on system reliability. 

Discussion of Comments 

Notice of proposed special conditions 

No. 25–09–03–SC for the Boeing Model 

747–8 and 747–8F airplanes was 

published in the Federal Register on 

April 8, 2009 (74 FR 15888). No 

comments were received and the special 

conditions are adopted as proposed. 

Applicability 

As discussed above, these special 

conditions are applicable to Boeing 

Model 747–8/–8F airplanes. Should 

Boeing apply at a later date for a change 

to the type certificate to include another 

model incorporating the same novel or 

unusual design features, the special 

conditions would apply to that model as 

well. 

Conclusion 

This action affects only certain novel 

or unusual design features of the Boeing 

Model 747–8/–8F airplanes. It is not a 

rule of general applicability. 

List of Subjects in 14 CFR Part 25 

Aircraft, Aviation safety, Reporting 

and recordkeeping requirements. 

The authority citation for these 

special conditions is as follows: 

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

44702, 44704. 


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40480 Federal Register / Vol. 74, No. 154 / Wednesday, August 12, 2009 / Rules and Regulations 

The Special Conditions 

A. General 

The Boeing Model 747–8/8F airplane 

is equipped with automatic control 

systems that affect the airplane’s 

structural performance, either directly 

or as a result of a failure or malfunction. 

The influence of these systems and their 

failure conditions must be taken into 

account when showing compliance with 

the requirements of Subparts C and D of 

part 25. The following criteria must be 

used for showing compliance with these 

special conditions for airplanes 

equipped with flight control systems, 

autopilots, stability augmentation 

systems, load alleviation systems, flutter 

control systems, fuel management 

systems, and other systems that either 

directly or as a result of failure or 

malfunction affect structural 

performance. If these special conditions 

are used for other systems, it may be 

necessary to adapt the criteria to the 

specific system. 

1. The criteria defined here only 

address the direct structural 

consequences of the system responses 

and performances and cannot be 

considered in isolation but should be 

included in the overall safety evaluation 

of the airplane. These criteria may in 

some instances duplicate standards 

already established for this evaluation. 

These criteria are only applicable to 

structural elements whose failure could 

prevent continued safe flight and 

landing. Specific criteria that define 

acceptable limits on handling 

characteristics or stability requirements 

when operating in the system degraded 

or inoperative mode are not provided in 

this special condition. 

2. Depending on the specific 

characteristics of the airplane, 

additional studies may be required that 

go beyond the criteria provided in these 

special conditions in order to 

demonstrate the capability of the 

airplane to meet other realistic 

conditions such as alternative gust or 

maneuver descriptions for an airplane 

equipped with a load alleviation system. 

3. The following definitions are 

applicable to these special conditions. 

(a) Structural performance: Capability 

of the airplane to meet the structural 

requirements of part 25. 

(b) Flight limitations: Limitations that 

can be applied to the airplane flight 

conditions following an in-flight 

occurrence and that are included in the 

Airplane Flight Manual (AFM) (e.g., 

speed limitations, avoidance of severe 

weather conditions). 

(c) Operational limitations: 

Limitations, including flight limitations, 

that can be applied to the airplane 

operating conditions before dispatch 

(e.g., fuel, payload and Master 

Minimum Equipment List (MMEL) 

limitations). 

(d) Probabilistic terms: The 

probabilistic terms (probable, 

improbable, extremely improbable) used 

in these special conditions are the same 

as those used in § 25.1309. 

(e) Failure condition: The term failure 

condition is the same as that used in 

§ 25.1309, however these special 

conditions apply only to system failure 

conditions that affect the structural 

performance of the airplane (e.g., system 

failure conditions that induce loads, 

change the response of the airplane to 

inputs such as gusts or pilot actions, or 

lower flutter margins). The system 

failure condition includes consequential 

or cascading effects resulting from the 

first failure. 

B. Effects of Systems on Structures 

1. General. The following criteria will 

be used in determining the influence of 

a system and its failure conditions on 

the airplane structural elements. 

2. System fully operative. With the 

system fully operative, the following 

apply: 

(a) Limit loads must be derived in all 

normal operating configurations of the 

system from all the limit conditions 

specified in subpart C (or used in lieu 

of those specified in subpart C), taking 

into account any special behavior of 

such a system or associated functions or 

any effect on the structural performance 

of the airplane that may occur up to the 

limit loads. In particular, any significant 

nonlinearity (rate of displacement of 

control surface, thresholds or any other 

system nonlinearities) must be 

accounted for in a realistic or 

conservative way when deriving limit 

loads from limit conditions. 

(b) The airplane must meet the 

strength requirements of part 25 (i.e., 

static strength, residual strength), using 

the specified factors to derive ultimate 

loads from the limit loads defined 

above. The effect of nonlinearities must 

be investigated beyond limit conditions 

to ensure the behavior of the system 

presents no anomaly compared to the 

behavior below limit conditions. 

However, conditions beyond limit 

conditions need not be considered when 

it can be shown that the airplane has 

design features that will not allow it to 

exceed those limit conditions. 

(c) The airplane must meet the 

aeroelastic stability requirements of 

§ 25.629. 

3. System in the failure condition. For 

any system failure condition not shown 

to be extremely improbable, the 

following apply: 

(a) At the time of occurrence, starting 

from 1g level flight conditions, a 

realistic scenario including pilot 

corrective actions, must be established 

to determine the loads occurring at the 

time of failure and immediately after 

failure. 

(1) For static strength substantiation, 

these loads multiplied by an appropriate 

factor of safety that is related to the 

probability of occurrence of the failure 

are ultimate loads to be considered for 

design. The factor of safety (F.S.) is 

defined in Figure 1. 


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Federal Register / Vol. 74, No. 154 / Wednesday, August 12, 2009 / Rules and Regulations 40481 

(2) For residual strength 

substantiation, the airplane must be able 

to withstand two thirds of the ultimate 

loads defined in subparagraph 3(a)(1). 

For pressurized cabins, these loads must 

be combined with the normal operating 

differential pressure. 

(3) Freedom from aeroelastic 

instability must be shown up to the 

speeds defined in § 25.629(b)(2). For 

failure conditions that result in speeds 

beyond VC/MC, freedom from 

aeroelastic instability must be shown to 

increased speeds, so that the margins 

intended by § 25.629(b)(2) are 

maintained. 

(4) Failures of the system that result 

in forced structural vibrations 

(oscillatory failures) must not produce 

loads that could result in detrimental 

deformation of the affected structural 

elements. 

(b) For continuation of flight, for an 

airplane in the system failed state and 

considering any appropriate 

reconfiguration and flight limitations, 

the following apply: 

(1) The loads derived from the 

following conditions (or used in lieu of 

the following conditions) at speeds up 

to VC/MC, or the speed limitation 

prescribed for the remainder of the 

flight, must be determined: 

(i) The limit symmetrical 

maneuvering conditions specified in 

§ 25.331 and in § 25.345. 

(ii) The limit gust and turbulence 

conditions specified in § 25.341 and in 

§ 25.345. 

(iii) The limit rolling conditions 

specified in § 25.349 and the limit 

asymmetrical conditions specified in 

§§ 25.367 and 25.427(b) and (c). 

(iv) The limit yaw maneuvering 

conditions specified in § 25.351. 

(v) The limit ground loading 

conditions specified in §§ 25.473, 

25.491 and 25.493. 

(2) For static strength substantiation, 

each part of the structure must be able 

to withstand the loads in paragraph 

(3)(b)(1) of this special condition 

multiplied by a factor of safety 

depending on the probability of being in 

this failure state. The factor of safety is 

defined in Figure 2. 

Qj = (Tj)(Pj) where: 

Tj = Average time spent in failure condition 

j (in hours) 

Pj = Probability of occurrence of failure mode 

j (per hour) 

Note: If Pj is greater than 10¥3 per flight 

hour then a 1.5 factor of safety must be 

applied to all limit load conditions specified 

in Subpart C. 

(3) For residual strength 

substantiation, the airplane must be able 

to withstand two thirds of the ultimate 

loads defined in paragraph (3)(b)(1) of 

this special condition. For pressurized 

cabins, these loads must be combined 

with the normal operating differential 

pressure. 

(4) If the loads induced by the failure 

condition have a significant effect on 

fatigue or damage tolerance then their 

effects must be taken into account. 

(5) Freedom from aeroelastic 

instability must be shown up to a speed 

determined from Figure 3. Flutter 

clearance speeds V′ and V′′ may be 

based on the speed limitation specified 

for the remainder of the flight using the 

margins defined by § 25.629(b). 


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40482 Federal Register / Vol. 74, No. 154 / Wednesday, August 12, 2009 / Rules and Regulations 

V′ = Clearance speed as defined by 

§ 25.629(b)(2). 

V′′ = Clearance speed as defined by 

§ 25.629(b)(1). 

Qj = (Tj)(Pj) where: 

Tj = Average time spent in failure condition 

j (in hours) 

Pj = Probability of occurrence of failure mode 

j (per hour) 

Note: If Pj is greater than 10¥3 per flight 

hour, then the flutter clearance speed must 

not be less than V′′. 

(6) Freedom from aeroelastic 

instability must also be shown up to V′ 

in Figure 3 above, for any probable 

system failure condition combined with 

any damage required or selected for 

investigation by § 25.571(b). 

Consideration of certain failure 

conditions may be required by other 

sections of part 25 regardless of 

calculated system reliability. Where 

analysis shows the probability of these 

failure conditions to be less than 10¥9, 

criteria other than those specified in this 

paragraph may be used for structural 

substantiation to show continued safe 

flight and landing. 

4. Failure indications. For system 

failure detection and indication, the 

following apply: 

(a) The system must be checked for 

failure conditions, not extremely 

improbable, that degrade the structural 

capability below the level required by 

part 25 or significantly reduce the 

reliability of the remaining system. As 

far as reasonably practicable, the flight 

crew must be made aware of these 

failures before flight. Certain elements 

of the control system, such as 

mechanical and hydraulic components, 

may use special periodic inspections, 

and electronic components may use 

daily checks, in lieu of detection and 

indication systems to achieve the 

objective of this requirement. These 

Certification Maintenance Requirements 

(CMRs) must be limited to components 

that are not readily detectable by normal 

detection and indication systems and 

where service history shows that 

inspections will provide an adequate 

level of safety. 

(b) The existence of any failure 

condition, not extremely improbable, 

during flight that could significantly 

affect the structural capability of the 

airplane and for which the associated 

reduction in airworthiness can be 

minimized by suitable flight limitations, 

must be signaled to the flight crew. For 

example, failure conditions that result 

in a factor of safety between the airplane 

strength and the loads of subpart C 

below 1.25, or flutter margins below V′′, 

must be signaled to the crew during 

flight. 

5. Dispatch with known failure 

conditions. If the airplane is to be 

dispatched in a known system failure 

condition that affects structural 

performance, or affects the reliability of 

the remaining system to maintain 

structural performance, then the 

provisions of this special condition 

must be met, including the provisions of 

paragraph 2 for the dispatched 

condition, and paragraph 3 for 

subsequent failures. Expected 

operational limitations may be taken 

into account in establishing Pj as the 

probability of failure occurrence for 

determining the safety margin in Figure 

1. Flight limitations and expected 

operational limitations may be taken 

into account in establishing Qj as the 

combined probability of being in the 

dispatched failure condition and the 

subsequent failure condition for the 

safety margins in Figures 2 and 3. These 

limitations must be such that the 

probability of being in this combined 

failure state and then subsequently 

encountering limit load conditions is 

extremely improbable. No reduction in 

these safety margins is allowed if the 

subsequent system failure rate is greater 

than 10¥3 per hour. 

Issued in Renton, Washington, on July 29, 

2009. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E9–19246 Filed 8–11–09; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. NM399; Special Conditions No. 

25–387–SC] 

Special Conditions: Boeing Model 747– 

8/–8F Airplanes; Additional Airframe 

Structural Design Requirements 

Related to Sudden Engine Stoppage 

Due to Fan Blade Failures 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for Boeing Model 747–8/–8F 

airplanes. These airplanes will have a 

novel or unusual design feature(s) 

associated with an increased engine size 

when compared to previous model 

airplanes. These larger engines with 

larger bypass fans are capable of 

producing higher and more complex 

dynamic loads than previously 

experienced in older designs. The 

applicable airworthiness regulations do 

not contain adequate or appropriate 

safety standards for this design feature. 

These special conditions contain the 

additional 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: September 11, 

2009. 

FOR FURTHER INFORMATION CONTACT: 

Mark Freisthler, FAA, Airframe & Cabin 


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