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0TreeLemur

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Everything posted by 0TreeLemur

  1. ^^^^^ this.
  2. So, the FAA makes the manufacturers of certified engine monitors hide the redline limits from the user, but the manufacturers of NexGen ATC transponders don't have to do the same for HEX codes or use encryption. Anyone with a Garmin gps must use proprietary software to set it up. Why would ADS-B out transponders need to be any different? This is really maddening. It hints that the entire ADS-B system has a fundamental flaw and will require a complete redesign or remain vulnerable. Yippee! Our units don't support encryption! So we all get to suffer a new costly ADS-B related mandate! I'll probably miss the free government money on that one too...
  3. I did this the other day in my C, and saw high EGT's. I had low MP (gear warning going off), prop full rpm, mixture about 1" from full rich, in about 1000 fpm descent. EGT's on all cyls. went up causing the EGT bars on the JPI900 to turn yellow. Advanced mixture full rich and that cooled them off. Density altitude 0. I was surprised that this condition could cause high EGTs. In another thread @Shadrach suggests that this is not a concern, just a peculiarity of the situation that won't harm anything.
  4. My co-pilot and I added these retro features to the tail and wing tip of our '67C. Just wanted to share. Vinyl decals purchased on eBay.
  5. Is the 632215 one of those airfoils that is better with a lot of ice? Not planning on testing the theory, of course, in an aircraft with 960lb UL. Just curious.
  6. Thanks everyone for your replies. Ross, I think you might be on to something here. Come to think of it, I think that I did push the prop control forward to high rpm to get the slight speed brake effect of the prop. Pushing burning gasses out into the exhaust sounds like something to avoid for the sake of the exhaust valves. All cylinders showed increased EGT, not just one. Yes, @Shadrach pushing the mixture in helped to bring all EGT's down. The intake air leak theory is possible @Pasturepilot but wishful thinking, I think, because this was a one-off event indicating stoopid pilot trick not mechanical issue. I think that if in the future there is a need to lose altitude rapidly near the field I should use a slip to lose energy, not high prop rpm. Burnin' and learnin' -Fred
  7. Sorry to hear about this. Their job is to upholstery as this is to painting restoration.
  8. Yes- same here. I have an EDM900, and I think the EGT bars turn yellow very near 1450F. I really like that feature. Once I took off without pushing the mixture in, and it was obvious when those bars turn yellow. Another time where having an engine monitor probably paid for itself many times over. I don't often see the yellow bars unless I screw up, and I always run ROP. -Fred
  9. It would be interesting to test that airfoil. Like you say- probably something better possible now. The optimization problem of cruise performance vs. safety/low speed characteristics is one of the features I liked about that paper. Best, Fred
  10. Yes, I had an experience during IFR training in March flying through moderate rain. My pitot-tube vent became partly plugged with water causing transients in the pitot-static system, which caused the AV-20S AOA sensor to freak out and start telling me that I had approached or exceeded what it thought was the critical AOA. Very distracting- flashing brightly bad AOA data. In reality my static instruments were extremely happy- nothing had changed and I was in a stabilized descent with low turbulence, the altimeter and VSI both stably indicating 500 fpm descent. After that I contacted Aerovonics, the original mfgr. of the AV-20S. I was told that the AOA sensor is uncalibratable in the Mooney airframe, and that I should disable it, which I did. I bought the AV-20S for (1) timer, (2), backup MEMS attitude indicator, and (3) TAS indication. After setting the temperature trim to calibrate the thermistor, it typically gives TAS of 150 kts (I wish) when according to the Garmin 430W it is more like 143 kts. I recently contacted uVonics regarding the apparent error in the TAS indication and they are working on improvements. I've not yet been informed of any new firmware being released. The AV-20S is (IMHO) a good timer. It gives engine run time as indicated by V>13.4V, and flight time according to TAS>40 kt. It includes two user-selectable count up/count-down timers that are useful. I most often use the flight time indication to remind me when to switch tanks. The backup AI is a very nice feature. Every time I compare it against my vacuum AI it agrees. When flying actual IFR in turbulence I'll often turn it to display the attitude indication to just have a confirmation that my brain is wrong. The AV-20S is not a great AOA sensor. Don't buy it for that. I could never calibrate it and was told by Aerovonics to give up trying. As @Hank educated me- it is a good clock with excellent 'Lagniappe". Good luck. Fred
  11. Our C has developed a case of cold-cabin since we redid the interior this fall. Yesterday I pulled the plastic overhead panel and went up for a draft diagnosis. I trimmed for cruise (cowl flaps closed, 24" MP, 2350 rpm, pulled the mixture about 1" back from full rich) and it took very little time to diagnose the source of the cold air. Sure enough, when we had the SB 208B inspection done last summer, they pulled some tape off the overhead air plenum where the tubular steel frame penetrates it and didn't replace it. This results in a sizeable leak that pressurizes the plastic headliner panel and results in cold air flooding in. I was only a few miles away from the field and at 2kft-ish. After turning around and heading back to the field I pulled the power to start my descent back to pattern altitude. Pulled MP back to 16" or so, and nosed over to get 800-1000 fpm descent and the EDM900 showed yellow EGTs. Mixture still at 1". So, pushed the mixture to full rich, and pulled the MP out some more. What gives? Can someone educate me about why the EGT would increase when the power is pulled to descend like that with what I consider to be the "standard" low altitude mixture setting? I was just surprised. I normally do cruise descents and don't see this behavior. It seems that I did something wrong. Thoughtful replies appreciated.
  12. Skip, This paper by Selig, Maughmer, and Somers (1995) is really interesting. It compares the root aerofoil on our Mooneys, the NACA 632215 against a more modern design NLF(1)-0015, showing about 25% less drag in cruise at Re~~9.0E+06. This more modern airfoil does indeed have an extensive region of laminar flow for a narrow range of alpha around cruise that they refer to as "laminar bucket" in the polar diagram. Wow- it also apparently is landable without flaps. I think it is a very interesting read. Fred SeligMaughmerSomers-1995-JofAC-NLF-Airfoil-Design.pdf
  13. The uVonics AV-20 https://uavionix.com/product/av-20s/ is a 2-1/4" flight timer with built in MEMS attitude indicator. Agrees very consistently with the vacuum AI in my a/c. The S model connects into the pitot-static system and an external air temperature probe to provide OAT and TAS (not super accurate in my experience). It has an AOA sensor that is uncalibratable on a Mooney according to an e-mail I received from the developer (former Aerovonics). I question whether it can be calibrated in any aircraft. I like it as a timer. Having a backup MEMS based AI is really comforting. It has an internal 30 minute battery backup.
  14. I'm not going to sew it, and I'm not asking for a random person who sews. I'm asking if anyone has a good recommendation for a person or company do this for aircraft seat belts. As an aviation community, I thought maybe someone has done this recently and can suggest someone I can contact. My vendor says they are too busy to get to it, and I thought I'd ask. Re-webbing with my end hardware would suffice. Regarding the recommendation by @Ross Taylor - I don't see how that would work on a shoulder belt. I used those with my kids' car seats back in the day, and it was fine because it was out of the way. Using one of those clips on a shoulder belt seems like it wouldn't be advisable as it would create a loop that would hang in front of the passenger and represent a hazard.
  15. Howdy ya'll, When we redid the interior, I bought new 3-point belts for the front, so we could move the installed 3-point belts to the back seats. All that worked fine. We put in the new push-button style female ends up front to reduce knuckle scrapie when actuating the Jbar. I measured the old shoulder harnesses, did not go with inertial reels for cost reason. Now they are just a bit too long to snug up. I'd like to shorten front and back shoulder harnesses about 4". The vendor of the new ones says that they will only do the ones they sold, and are really backed up. That leaves me not getting this done soon, and only the fronts. Anybody know someone who can do this kind of work? Thanks, Fred
  16. General aviation has also changed a lot. When I was a kid hanging around the local airport, most GA was piston. Now it is at a minimum turboprop, with a lot of jet traffic. Piston GA is greatly diminished from the 80's and 90's. I find it amazing when I'm enroute at 7500 or 8500 in our C, how little traffic their is down where we fly. Only when we near class C or B is there much conflict.
  17. If you forgo receiving the MAPA Log magazine with its stinky ink, and just look at the online version and its archives, you save I think $11/y on dues.
  18. On 11/15 at about 10:50 a.m. over the Colorado Rockies, I saw this. I wasn't flying- I was a passenger in an RJ. But it was pretty cool to see. We were at FL 240, flying from GJT-DEN.
  19. According to google maps, the image is (C) 2019 CNES Airbus/Maxar Technologies. When I look at other parts of the world, the date changes, so I think they are trying to give attribution to the image provider and accurate date. Sure, they are probably wrong sometimes. My house shows an image from last winter, which is also stamped (C) 2019.
  20. Ok, thanks for sharing that link. Now I see why my skepticism is unfounded. That is so far from a stock airframe it is unbelievable. I would bet that this CAFE Mooney can cruise at 170 with 75% power.
  21. Must have been near-magic, but after all LoPresti was undeniably "the man" when it comes to Mooney aircraft and speed.
  22. I couldn't tell from the photo. An E and a C are the same airframe. I don't think the IO360 vs. O360 would make that much difference in cruise when connected to the same propeller.
  23. So, it is a firefighter's playground. Still weird with the F-14 and two C-130's.
  24. Hi ya'll, Out of curiosity tonight I was exploring a TFR that is coming into effect soon near San Angelo, TX. I pulled up Google maps to see what's there. Recent photo taken by satellite of Goodfellow Air Force base in San Angelo, TX, attached. I see an F-14 at an Air Force base... Wha? They were all retired by the US in 2006 or so. For an Air Force base, Goodfellow seems to be pretty short on runways. How did that and those two C-130's get in there? Why are they there? How are they going to take off? JATO bottles??? Also, there seems to be a tanker trailer lying on its side. Huh? Anybody have any idea (1) why is there a TFR in effect this week near San Angelo, Texas, from 3,500 to 18,000 ft. Why is there an F-14 on an Air Force Base in 2019??? Why would a tanker be lying on its side? My brain hurts. Genius of MS, please help me out. It looks like they do a lot of training there for firefighting. Are all these things sacrifices for the gods of fire training? Anybody know? Link to view on google maps: Thanks.
  25. I'm a little bit skeptical of the 170 KTAS C model and here's why. Assuming a standard atmosphere, at 6500 ft, 170 KTAS would be 154 KIAS. According to Sequoia Benchmark, with WOT (MP=24.4") and 2400 rpm, to achieve 170 KTAS, the drag coefficient in a Mooney with stock Hartzell propeller (87.5% eff.) can at most be 0.015. Such a slick Mooney C does not exist? According to the data in Sequoia, a M20J has a drag coeff measured of about 0.0168. A M20C could hardly be lower, right? From the data in Sequoia, M20J N1220G has a cruise speed at 6500' STP with 24.4" MP and 2400 rpm (70% POH pwr) of 163 kts. To get the J up to 170 kts cruise, rpm must increase to 2630 rpm. Who does that? I'm calling B.S. on the 170 kt C unless they were cruising at much higher than normal rpm.
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