Pratt & Whitney

Pratt & Whitney agree with the general historical basis for the CFR 14 Part 34 section 34.11 Fuel Venting Standards as summarized in the subject FAA Policy Determination. We agree that the original intention of the rule was to eliminate the means to certify products incorporating systems which would vent raw fuel overboard during various operating phases/conditions. We are unable to comment on the specific 747/787 certification issue which precipitated the need for the subject Policy Determination since our products were not involved. We do, however, offer the additional following comments for consideration. The definitions in CFR 14 Part 34 section 33.1, specifically those for "Fuel Venting Emissions" and "Exhaust Emissions" seem to exclude the situation described in the subject Policy Determination. The definition for "fuel venting emissions" says that they are "...exclusive of hydrocarbons in exhaust emissions..." while "exhaust emissions" are defined as "... substances emitted into the atmosphere from the exhaust discharge nozzle of an (aircraft engine)". Therefore one could conclude that the definitions were created to focus the rule on fuel vented thru other overboard means exclusive of the exhaust nozzle. Any unburned fuel vapor exiting the exhaust nozzle due to normal operation of the fuel system would still be compliant to the Part 34.11 standards presuming that it was not sufficient to cause an unsafe condition under the Part 33 Engine standards. Thank you for the opportunity to comment on this FAA Policy Determination.