# Title 40

## SECTION 1054.315

### 1054.315 How do I know when my engine family fails the production-line testing requirements

§ 1054.315 How do I know when my engine family fails the production-line testing requirements?This section describes the pass-fail criteria for the production-line testing requirements. We apply these criteria on an emission-family basis. See § 1054.320 for the requirements that apply to individual engines that fail a production-line test.

(a) Calculate your test results as follows:

(1) *Initial and final test results.* Calculate and round
the test results for each engine. If you do several tests on an
engine, calculate the initial results for each test, then add all
the test results together and divide by the number of tests. Round
this final calculated value for the final test results on that
engine.

(2) *Final deteriorated test results.* Apply the
deterioration factor for the engine family to the final test
results (see § 1054.240(c)).

(3) *Round deteriorated test results.* Round the results to
the number of decimal places in the emission standard expressed to
one more decimal place.

(b) Construct the following CumSum Equation for each engine family for HC + NOX and CO emissions:

Ci = Max [0 or Ci-1 + Xi−(STD + 0.25 × σ)] Where: Ci = The current CumSum statistic. Ci-1 = The previous CumSum statistic. For the first test, the CumSum statistic is 0 (i.e., C1 = 0). Xi = The current emission test result for an individual engine. STD = Emission standard (or family emission limit, if applicable).(c) Use final deteriorated test results to calculate the variables in the equation in paragraph (b) of this section (see § 1054.315(a)).

(d) After each new test, recalculate the CumSum statistic.

(e) If you test more than the required number of engines, include the results from these additional tests in the CumSum Equation.

(f) After each test, compare the current CumSum statistic, Ci, to the recalculated Action Limit, H, defined as H = 5.0 × σ.

(g) If the CumSum statistic exceeds the Action Limit in two consecutive tests, the engine family fails the production-line testing requirements of this subpart. Tell us within ten working days if this happens. You may request to amend the application for certification to raise the FEL of the entire engine family as described in § 1054.225(f).

(h) If you amend the application for certification for an engine family under § 1054.225, do not change any previous calculations of sample size or CumSum statistics for the model year.