This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

16287 

Vol. 72, No. 64 

Wednesday, April 4, 2007 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2007–27756; Directorate 

Identifier 2006–NM–255–AD] 

RIN 2120–AA64 

Airworthiness Directives; McDonnell 

Douglas Model DC–8–62, DC–8–62F, 

DC–8–63, DC–8–63F, DC–8–72, DC–8– 

72F, and DC–8–73F Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for all 

McDonnell Douglas Model DC–8–62, 

DC–8–62F, DC–8–63, DC–8–63F, DC–8– 

72, DC–8–72F, and DC–8–73F airplanes. 

This proposed AD would require 

deactivating certain components (the 

sump heater, scavenge valve, and 

scavenge pump) of the center wing fuel 

tank. This proposed AD results from 

fuel system reviews conducted by the 

manufacturer. We are proposing this AD 

to prevent certain conditions related to 

these components, which could lead to 

a possible ignition source in the fuel 

tank and a potential fire or explosion. 

DATES: We must receive comments on 

this proposed AD by May 21, 2007. 

ADDRESSES: Use one of the following 

addresses to submit comments on this 

proposed AD. 

• DOT Docket Web site: Go to 

http://dms.dot.gov and follow the 

instructions for sending your comments 

electronically. 

• Government-wide rulemaking Web 

site: Go to http://www.regulations.gov 

and follow the instructions for sending 

your comments electronically. 

• Mail: Docket Management Facility, 

U.S. Department of Transportation, 400 

Seventh Street, SW., Nassif Building, 

room PL–401, Washington, DC 20590. 

• Fax: (202) 493–2251. 

• Hand Delivery: Room PL–401 on 

the plaza level of the Nassif Building, 

400 Seventh Street, SW., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

Contact Boeing Commercial 

Airplanes, Long Beach Division, 3855 

Lakewood Boulevard, Long Beach, 

California 90846, Attention: Data and 

Service Management, Dept. C1–L5A 

(D800–0024), for the service information 

identified in this proposed AD. 

FOR FURTHER INFORMATION CONTACT: Serj 

Harutunian, Aerospace Engineer, 

Propulsion Branch, ANM–140L, FAA, 

Los Angeles Aircraft Certification 

Office, 3960 Paramount Boulevard, 

Lakewood, California 90712–4137; 

telephone (562) 627–5254; fax (562) 

627–5210. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to submit any relevant 

written data, views, or arguments 

regarding this proposed AD. Send your 

comments to an address listed in the 

ADDRESSES section. Include the docket 

number ‘‘FAA–2007–27756; Directorate 

Identifier 2006–NM–255–AD’’ at the 

beginning of your comments. We 

specifically invite comments on the 

overall regulatory, economic, 

environmental, and energy aspects of 

the proposed AD. We will consider all 

comments received by the closing date 

and may amend the proposed AD in 

light of those comments. 

We will post all comments we 

receive, without change, to http:// 

dms.dot.gov, including any personal 

information you provide. We will also 

post a report summarizing each 

substantive verbal contact with FAA 

personnel concerning this proposed AD. 

Using the search function of that Web 

site, anyone can find and read the 

comments in any of our dockets, 

including the name of the individual 

who sent the comment (or signed the 

comment on behalf of an association, 

business, labor union, etc.). You may 

review DOT’s complete Privacy Act 

Statement in the Federal Register 

published on April 11, 2000 (65 FR 

19477–78), or you may visit http:// 

dms.dot.gov. 

Examining the Docket 

You may examine the AD docket on 

the Internet at http://dms.dot.gov, or in 

person at the Docket Management 

Facility office between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. The Docket 

Management Facility office (telephone 

(800) 647–5227) is located on the plaza 

level of the Nassif Building at the DOT 

street address stated in the ADDRESSES

section. Comments will be available in 

the AD docket shortly after the Docket 

Management System receives them. 

Discussion 

The FAA has examined the 

underlying safety issues involved in fuel 

tank explosions on several large 

transport airplanes, including the 

adequacy of existing regulations, the 

service history of airplanes subject to 

those regulations, and existing 

maintenance practices for fuel tank 

systems. As a result of those findings, 

we issued a regulation titled ‘‘Transport 

Airplane Fuel Tank System Design 

Review, Flammability Reduction and 

Maintenance and Inspection 

Requirements’’ (66 FR 23086, May 7, 

2001). In addition to new airworthiness 

standards for transport airplanes and 

new maintenance requirements, this 

rule included Special Federal Aviation 

Regulation No. 88 (‘‘SFAR 88,’’ 

Amendment 21–78, and subsequent 

Amendments 21–82 and 21–83). 

Among other actions, SFAR 88 

requires certain type design (i.e., type 

certificate (TC) and supplemental type 

certificate (STC)) holders to substantiate 

that their fuel tank systems can prevent 

ignition sources in the fuel tanks. This 

requirement applies to type design 

holders for large turbine-powered 

transport airplanes and for subsequent 

modifications to those airplanes. It 

requires them to perform design reviews 

and to develop design changes and 

maintenance procedures if their designs 

do not meet the new fuel tank safety 

standards. As explained in the preamble 

to the rule, we intended to adopt 

airworthiness directives to mandate any 

changes found necessary to address 

unsafe conditions identified as a result 

of these reviews. 

In evaluating these design reviews, we 

have established four criteria intended 

to define the unsafe conditions 

associated with fuel tank systems that 

require corrective actions. The 

percentage of operating time during 

which fuel tanks are exposed to 

flammable conditions is one of these 

criteria. The other three criteria address 


cprice-sewell on PROD1PC61 with PROPOSALS
16288 Federal Register / Vol. 72, No. 64 / Wednesday, April 4, 2007 / Proposed Rules 

the failure types under evaluation: 

Single failures, single failures in 

combination with a latent condition(s), 

and in-service failure experience. For all 

four criteria, the evaluations included 

consideration of previous actions taken 

that may mitigate the need for further 

action. 

We have determined that the actions 

identified in this proposed AD are 

necessary to reduce the potential of 

ignition sources inside fuel tanks, 

which, in combination with flammable 

fuel vapors, could result in fuel tank 

explosions and consequent loss of the 

airplane. 

We have received a report of an 

overheated and damaged sump heater 

on a center wing fuel tank. Investigation 

revealed that several incidents of this 

kind had occurred in the past and that 

damage was caused by fatigue failure of 

the sump heater thermostat. 

Additionally, SFAR 88 analysis has 

identified certain lightning protection 

issues with the center wing crossfeed 

and scavenge valves, as well as 

frictional heating and sparking issues 

with the scavenge pump. Deactivating 

the sump heater, the scavenge valve and 

the scavenge pump will address all 

three issues. If not corrected, operation 

with a damaged sump heater thermostat 

or scavenge pump, or operation of the 

crossfeed and scavenge valves during 

lightning conditions could lead to a 

possible ignition source in the fuel tank 

and a potential fire or explosion. 

Relevant Service Information 

We have reviewed Boeing Alert 

Service Bulletin DC8–28A089, dated 

November 1, 2006. The service bulletin 

describes procedures for deactivating 

the sump heater, scavenge valve, and 

scavenge pump of the center wing fuel 

tank. Accomplishing the actions 

specified in the service information is 

intended to adequately address the 

unsafe condition. 

FAA’s Determination and Requirements 

of the Proposed AD 

We have evaluated all pertinent 

information and identified an unsafe 

condition that is likely to exist or 

develop on other airplanes of this same 

type design. For this reason, we are 

proposing this AD, which would require 

accomplishing the actions specified in 

the service information described 

previously. 

Costs of Compliance 

There are about 119 airplanes of the 

affected design in the worldwide fleet. 

The following table provides the 

estimated costs for U.S. operators to 

comply with this proposed AD. 

ESTIMATED COSTS

Work hours Average labor rate per 

hour Cost per airplane Number of U.S.-registered airplanes Fleet cost 

6 $80 $480 84 $40,320 

Authority for This Rulemaking 

Title 49 of the United States Code 

specifies the FAA’s authority to issue 

rules on aviation safety. Subtitle I, 

Section 106, describes the authority of 

the FAA Administrator. Subtitle VII, 

Aviation Programs, describes in more 

detail the scope of the Agency’s 

authority. 

We are issuing this rulemaking under 

the authority described in Subtitle VII, 

Part A, Subpart III, Section 44701, 

‘‘General requirements.’’ Under that 

section, Congress charges the FAA with 

promoting safe flight of civil aircraft in 

air commerce by prescribing regulations 

for practices, methods, and procedures 

the Administrator finds necessary for 

safety in air commerce. This regulation 

is within the scope of that authority 

because it addresses an unsafe condition 

that is likely to exist or develop on 

products identified in this rulemaking 

action. 

Regulatory Findings 

We have determined that this 

proposed AD would not have federalism 

implications under Executive Order 

13132. This proposed AD would not 

have a substantial direct effect 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. 

For the reasons discussed above, I 

certify that the proposed regulation: 

1. Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866; 

2. Is not a ‘‘significant rule’’ under the 

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. 

We prepared a regulatory evaluation 

of the estimated costs to comply with 

this proposed AD and placed it in the 

AD docket. See the ADDRESSES section 

for a location to examine the regulatory 

evaluation. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Safety. 

The Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 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. The Federal Aviation 

Administration (FAA) amends § 39.13 

by adding the following new 

airworthiness directive (AD): 

McDonnell Douglas: Docket No. FAA–2007–

27756; Directorate Identifier 2006–NM–

255–AD. 

Comments Due Date 

(a) The FAA must receive comments on 

this AD action by May 21, 2007. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to all McDonnell 

Douglas Model DC–8–62, DC–8–62F, DC–8–

63, DC–8–63F, DC–8–72, DC–8–72F, and DC–

8–73F airplanes, certificated in any category. 

Unsafe Condition 

(d) This AD results from fuel system 

reviews conducted by the manufacturer. We 

are issuing this AD to prevent certain 

conditions related to the sump heater, 

scavenge valve, and scavenge pump of the 

center wing fuel tank, which could lead to a 

possible ignition source in the fuel tank and 

a potential fire or explosion. 

Compliance 

(e) You are responsible for having the 

actions required by this AD performed within 

the compliance times specified, unless the 

actions have already been done. 

Deactivation 

(f) Within 24 months after the effective 

date of this AD, deactivate the sump heater, 


cprice-sewell on PROD1PC61 with PROPOSALS
Federal Register / Vol. 72, No. 64 / Wednesday, April 4, 2007 / Proposed Rules 16289 

scavenge valve, and scavenge pump of the 

center wing fuel tank, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin DC8–28A089, dated 

November 1, 2006. 

Alternative Methods of Compliance 

(AMOCs) 

(g)(1) The Manager, Los Angeles Aircraft 

Certification Office, FAA, has the authority to 

approve AMOCs for this AD, if requested in 

accordance with the procedures found in 14 

CFR 39.19. 

(2) Before using any AMOC approved in 

accordance with § 39.19 on any airplane to 

which the AMOC applies, notify the 

appropriate principal inspector in the FAA 

Flight Standards Certificate Holding District 

Office. 

Issued in Renton, Washington, on March 

26, 2007. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E7–6269 Filed 4–3–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2007–27755; Directorate 

Identifier 2006–NM–289–AD] 

RIN 2120–AA64 

Airworthiness Directives; Bombardier 

Model DHC–8–400 Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain Bombardier Model DHC–8–400 

series airplanes. This proposed AD 

would require revising the Limitations 

section of the airplane flight manual to 

include procedures for pulling the 

‘‘HYD PWR XFER’’ circuit breaker in the 

event of the loss of all hydraulic fluid 

in the No. 1 or No. 2 hydraulic system. 

This proposed AD results from reports 

of fluid loss in the No. 2 hydraulic 

system, causing the power transfer unit 

to overspeed, increasing the fluid flow 

within the No. 1 hydraulic system. We 

are proposing this AD to prevent 

possible loss of both the No. 1 and No. 

2 hydraulic systems, resulting in the 

potential loss of several functions 

essential for safe flight and landing of 

the airplane. 

DATES: We must receive comments on 

this proposed AD by May 4, 2007. 

ADDRESSES: Use one of the following 

addresses to submit comments on this 

proposed AD. 

• DOT Docket Web site: Go to 

http://dms.dot.gov and follow the 

instructions for sending your comments 

electronically. 

• Government-wide rulemaking Web 

site: Go to http://www.regulations.gov 

and follow the instructions for sending 

your comments electronically. 

• Mail: Docket Management Facility, 

U.S. Department of Transportation, 400 

Seventh Street, SW., Nassif Building, 

Room PL–401, Washington, DC 20590. 

• Fax: (202) 493–2251. 

• Hand Delivery: Room PL–401 on 

the plaza level of the Nassif Building, 

400 Seventh Street, SW., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

Contact Bombardier, Inc., Bombardier 

Regional Aircraft Division, 123 Garratt 

Boulevard, Downsview, Ontario M3K 

1Y5, Canada, for service information 

identified in this proposed AD. 

FOR FURTHER INFORMATION CONTACT: Ezra 

Sasson, Aerospace Engineer, Systems 

and Flight Test Branch, ANE–172, FAA, 

New York Aircraft Certification Office, 

1600 Stewart Avenue, Suite 410, 

Westbury, New York 11590; telephone 

(516) 228–7320; fax (516) 794–5531. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to submit any relevant 

written data, views, or arguments 

regarding this proposed AD. Send your 

comments to an address listed in the 

ADDRESSES section. Include the docket 

number ‘‘FAA–2007–27755; Directorate 

Identifier 2006–NM–289–AD’’ at the 

beginning of your comments. We 

specifically invite comments on the 

overall regulatory, economic, 

environmental, and energy aspects of 

the proposed AD. We will consider all 

comments received by the closing date 

and may amend the proposed AD in 

light of those comments. 

We will post all comments we 

receive, without change, to http:// 

dms.dot.gov, including any personal 

information you provide. We will also 

post a report summarizing each 

substantive verbal contact with FAA 

personnel concerning this proposed AD. 

Using the search function of that web 

site, anyone can find and read the 

comments in any of our dockets, 

including the name of the individual 

who sent the comment (or signed the 

comment on behalf of an association, 

business, labor union, etc.). You may 

review the DOT’s complete Privacy Act 

Statement in the Federal Register 

published on April 11, 2000 (65 FR 

19477–78), or you may visit http:// 

dms.dot.gov. 

Examining the Docket 

You may examine the AD docket on 

the Internet at http://dms.dot.gov, or in 

person at the Docket Management 

Facility office between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. The Docket 

Management Facility office (telephone 

(800) 647–5227) is located on the plaza 

level of the Nassif Building at the DOT 

street address stated in the ADDRESSES

section. Comments will be available in 

the AD docket shortly after the Docket 

Management System receives them. 

Discussion 

Transport Canada Civil Aviation 

(TCCA), which is the airworthiness 

authority for Canada, notified us that an 

unsafe condition may exist on certain 

Bombardier Model DHC–8–400 series 

airplanes. TCCA advises that it has 

received several reports of fluid loss in 

the No. 2 hydraulic system, causing the 

power transfer unit (PTU) to overspeed. 

This resulted in pressure fluctuations 

and increased fluid flow within the No. 

1 hydraulic system. In one case, the 

hydraulic system control logic did not 

shut down the PTU, and the overspeed 

condition persisted, resulting in the 

illumination of the No. 1 ‘‘HYD FLUID 

HOT’’ caution light. This caution light 

indicated that the hydraulic fluid 

temperature had exceeded 225 degrees 

Fahrenheit. Had the temperature of the 

hydraulic fluid continued to increase to 

275 degrees Fahrenheit, the No. 1 

system hydraulic firewall shutoff would 

have closed, leaving only the standby 

power unit (SPU) available. The SPU is 

not capable of meeting the increased 

flow demands of the PTU and other No. 

1 hydraulic system services. Therefore, 

the No. 1 hydraulic system would have 

also been lost, leaving only the No. 3 

hydraulic system available. Inoperative 

systems would include flaps, brakes and 

emergency brakes, nose wheel steering, 

and all primary flight controls other 

than elevator control and degraded 

aileron control. 

This condition, if not corrected, could 

result in the potential loss of several 

functions essential for safe flight and 

landing of the airplane. 

Relevant Service Information 

Bombardier has issued the following 

airplane flight manual (AFM) temporary 

amendments: 


cprice-sewell on PROD1PC61 with PROPOSALS