Don, Either way, you'll need to have an aerodynamic trim tab on the elevator to get approval for the 1320 lb. gross weight STC.
The STC requires that you change the **configuration** of the plane to match that of the D or E and G models -- but -- without changing the legal model of the aircraft. This can be achieved with either the straight or "split" elevator. As the STC only changes the gross weight up to 1320 lb., the plane stays legal for use by a Sport Pilot. If you keep the straight elevator, it must be limited to the 9° up travel (the 415-C and 415-CD have 13° elevator up travel). This further restriction of the elevator up travel increases your touchdown speed by about 5-7 mph. (And, the aerodynamic trim tab is required.) Why the FAA required the 9° up travel limit may take a chapter in Bill Bayne's book when it eventually comes out (add together higher gross weight, full power with C-85 engine, max up travel and possible misrigging by the mechanic). But the gods of the FAA do so require. Note that I flew 800 hours with the 9° elevator up travel limit and felt quite comfortable. This included a lot of operation at fields that most people consider to be pretty short. If you change to the "split" elevator with the center section cut out, the slipstream will mostly go through the cut out. This lets the plane keep the same trim from idle to full power. Because the trim isn't affected by power, the up travel is set to 20° to return the touchdown speed to the 415-C and CD model's touchdown near 50 mph. The split elevator does NOT allow a higher gross weight in itself. It's just an effective way to keep the low touchdown airspeed while meeting the FAA's stability requirement at higher gross weight and full power. If that doesn't explain the situation adequately, let me know and I'll try again. Ed > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of dongeneda2000 > Sent: Tuesday, December 29, 2009 7:41 AM > To: [email protected] > Subject: [ercoupe-tech] 1320 lb STC > > I have an early 415C with the "rubberband on the yoke" type trim adjustment, window > style crank on the dash. > To convert to 1320lb I must either put in the trim tab type trim (which is expensive and > troublesome to do and I don't want to do it), or change the elevator to a "split type" > from an E model. > What is so special about the E model elevator that makes it carry more weight? > > > > ------------------------------------ > > Yahoo! Groups Links > > >
