AviZone

Grade 100VLL aviation gasoline (avgas) is developed to provide a lower lead alternative to 100LL in response to impending environmental regulations. Grade 100VLL is identical to 100LL in all aspects, except that the maximum lead content is reduced by about 19%.  Grade 100VLL has the same minimum octane rating and will provide the same level of anti-knock performance as 100LL and 100 avgas grades. The FAA collaborated with industry on the ASTM International task force that evaluated data supporting the incorporation of grade 100VLL into specification D910. The FAA determined that grade 100 VLL meets all of the performance requirements of grades 80, 91, 100, and 100LL and will perform identically in existing aircraft and engines FAA  Recommendation 1. Grade 100VLL avgas is acceptable for use on those aircraft and engines that are approved to operate with grades 80, 91, 100, or 100LL avgas. 2. ASTM D910 specifies blue coloration for both grade 100VLL avgas and grade...

" (We saw) evidence of oil streaming down the belly and to the tail (of this 172S)," says this mechanic. "And oil was noted dripping from a drain tube below the firewall. This drain tube connected to an overflow fitting on the engine mounted mechanical fuel pump (P/N LW15473). The pump core was disassembled and oil was found leaking through the first of two diaphragms in this dual diaphragm pump. The rubber material covering the base material of the diaphragm was found flaking off. This base material is porous—allowing oil through the first diaphragm and into the ring chamber that allows oil to drain overboard without contamination of the fuel side of the pump. Failure of the second diaphragm would allow fuel injection to become contaminated. In a two month period, we have found two pumps draining oil overboard. A third aircraft was found with oil contamination in the fuel injection system." ( curtsy: flight safety magazine)   

                                                                                            A report on an accident to a homebuilt Jabiru aircraft which suffered a jammed rudder control on landing, causing it to leave the runway surface and turn over, injuring the occupants. The jam had apparently occurred as a result of insufficient clearance between the leading edge of the rudder and the trailing edge of the fin.                  Although jamming of aircraft control surfaces is not common in flight, it can have catastrophic consequences. As the AAIB report points out, aerodynamic or inertial loads can distort aircraft skin during flight, and any possibility of such distortion causing a control jam should ...