Search the Community

Hi, Any performance specialists? I'm interested to understand the takeoff performance differences in the J model. Apart form some aerodynamic improvements the sizeable disparity between the attached 1977 and 1996 issued POH in takeoff performance I attribute to A) regulator imposing increased factoring / buffer inbuilt as time went on and/or the 'speed at 50ft'. I note the stall speeds in both books listed as 57kt in takeoff config (Flap 15 deg), yet the speed at 50ft in the 1977 book only 71kts and in the 1996 book 76kts . The lower margin above stall speed will achieve better numbers for takeoff distance I understand but I'm not certain its the only factor at play here in the differences. 71 kts is 24.56% margin above stall and 76 kts is 33.33% margin above 1G stall. Takeoff Safety speed for light aircraft I believe has to be at least 20 percent above stall speed?? Was there an FAA change at some stage on this? Are the 1977 figures allowed to be used... certainly not providing as much margin as later book data in the real world.

I have replaced the original exhaust off my 1983 M20J with new. This was a proactive step as part of my preventive maintenance philosophy for a plane I intend to keep a long time. No leaks or specific problems found, but that said, the exhaust is a wear item and original, about 2400 hours and 32 years, and the price reflects this. For someone who wants to put off a new exhaust a little longer in order to coordinate with their TBO or major annual, this may be for you. Only what is seen here is included: 4 risers, muffler/collector, and tailpipe. Specifically, the heater shroud and tailpipe hardware are not included. It is drilled for EGT probes on all 4 stacks. The #2 cylinder swage fit area was repaired once as part of my pre-purchase squawks. That was over 400 hours ago. Some of you are bound to wonder, so I'll add that I went with a new Knisely exhaust. Powerflow was more than I could afford/justify during this annual, but was surely tempted. Feel free to discuss the merits of my decisions amongst yourselves. I'll add that it was only flown ROP except when it was flown LOP, unless the moon was full, in which case I used camguard. :-) $300 plus shipping costs. Or pick it up at KFUL (other SoCal airports possible if we can coordinate schedules and you buy lunch) Reply or PM with any questions. thanks, -dan