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rwilkins on PROD1PC63 with PROPOSALS
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Federal Register / Vol. 73, No. 50 / Thursday, March 13, 2008 / Proposed Rules
Issued in Fort Worth, Texas, on March 4,
2008.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft
Certification Service.
[FR Doc. E8–5068 Filed 3–12–08; 8:45 am]
BILLING CODE 4910–13–P
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 86
[EPA–HQ–OAR–2006–0072; FRL–8539–4
RIN 2060–069
In-Use Testing for Heavy-Duty Diesel
Engines and Vehicles; Emission
Measurement Accuracy Margins for
Portable Emission Measurement
Systems and Program Revisions
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Notice of proposed rulemaking.
SUMMARY: In a rule published on June
14, 2005, EPA established a
manufacturer-run, in-use testing
program for heavy-duty diesel vehicles.
The program requires engine
manufacturers to measure exhaust
emissions from their diesel engines
using portable emissions measurement
systems during real-world operation. At
the time the rule was promulgated, EPA
established interim emission
measurement ‘‘accuracy’’ margins for
the requisite portable emission
measurement devices pending the
development of final accuracy margins
through a comprehensive research
program. This notice proposes to adopt
the resulting final accuracy margins for
gaseous pollutants. Also, this rule
proposes to make several changes to the
program in the early years of in-use
testing. First, we are proposing to
eliminate the first calendar year, i.e.,
2006, of the two-year pilot program for
particulate emissions (PM) in response
to engine manufacturers’ concerns,
which primarily relate to the availability
and efficacy of the requisite portable
measurement systems (PEMS) for that
pollutant. Second, due to a delay in
developing the final accuracy margin for
PM under the aforementioned
comprehensive research program, we
are proposing to delay t