David_H

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About David_H

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    1I9
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    M20F

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  1. Wow. Was a go-around not an option? That seemed like a high-risk maneuver at 100' given the circumstances shown. Even though I tilted my head during the video to get the same sight picture (for full effect of course), I can't say I'd try that one with passengers onboard... even with Thunderstruck playing in the background
  2. @bradp How do you like the audio panel placement on the right side?
  3. Tell us all how the leading edge camber affects this image...
  4. ... leading edge camber on a Mooney airfoil. MS isn't a Journal publication and certainly doesn't have a scientific review process to vet information... but really?
  5. The GA insurance market appears to currently be in uncharted territory. At one end of the market high time pilots that have been preferred in the recent past are moving into the +75 age market at a faster pace. It appears as though many Underwriters have a low interest in insuring those pilots. These are the same pilots that have paid large sums of money to the insurance industry over the span of many years. Its very sad. At the other end of the market are pilots with low complex time. Underwriters don't appear to be interested in those pilots either. Its no surprise that Underwriters appear to be trying find ways to hedge their bets on both ends of the GA market. This doesn't appear to be sustainable with the shrinking pilot population on both ends of the GA market. What do you think is coming next @Parker_Woodruff? I'll ask for a 5yr outlook... but will very happily settle for a 1-2yr outlook. The insurance market for GA is an ugly mess at the moment and doesn't show signs of being able to continue in it's current state due to the aging (and shrinking) pilot population.
  6. Did you use 113MHz for the tuning frequency to calculate the Balun stub length (lambda/4) shown in 43.13? What length do you arrive at?
  7. Thanks for the replies @EricJ and @Gagarin. Eric, you're correct that Fig 3-6 came from AC 43.13-2B. The coax removed was originally constructed in this manner. It had a Balun fabricated with an approximate length of 16" which could possibly correlate to using a velocity factor for the dielectric sheath. AC 43.13-2B makes no mention of using the velocity factor though. It's also possible that the Balun tuning length was split between the bands for the VOR/GS and the LOC... perhaps somewhere around 190MHz instead of 113MHz. This would also yield a Balun length of approx 16" without using a velocity factor. As Jose stated, the Balun is tuned for a very narrow frequency band. This makes one ask if it would perform very well at any of the operating frequencies since the tuning frequency is so far away from any of the operating bands. Also, does the higher GS frequency band need to be tuned at all since long-range reception isn't necessary for the GS band?
  8. There appear to be several different Balun designs being used to help with unbalanced antenna transmission lines (two designs are shown below). One item that seems rather inconclusive so far is the inclusion of the velocity factor for the coax. It appears as if the coax velocity factor would apply for the design shown in Fig 3-6 below... but not for the folded Pawsey Stub design due to the Balun being outside of the dielectric sheath. Is there a benefit to using a Pawsey Stub Balun over the one depicted in Fig 3-6? The design in Fig 3-6 leaves the transmission line open and the second purposely shorts the transmission line across the Balun. Formula: (300/f) x (velocity factor) x (0.25) = 1/4 wavelength Balun length; f=113 [MHz] If a velocity factor of 0.69 is used for RG400... calculations lead to approx. 18" for the 1/4 wavelength Balun length. If a velocity factor of 1 is used (air)... calculations lead to approx. 26" for the 1/4 wavelength Balun length. Are there any EE's here that can chime in on this one?
  9. The Mooney debacle is a sad deal for everyone. I certainly wont argue about who's at fault since I don't know all the facts and it really doesn't matter at this point. It would be a really tough sell to deliver a new airplane to anyone with the funds to make the purchase after this. A shaky or nonexistent support structure would be a non-starter for anyone with the funds to make the purchase (new or renewed). Mooney will likely not be able to recover from this in it's current form. The best outcome would be for someone that had a different vision to purchase the company.
  10. If engineers in China could have done better with the program, why didn't they do it there? It's doubtful the design was a complete flop. It appears as if unattainable expectations were set. The reasons why are unknown.
  11. I quoted "failed design" because nobody seems to know exactly what happened. It's unlikely that it was a complete failure if a competent development team was assembled. They appeared to have shuttered the design effort for some reason. To be clear... no blame is being passed since the details aren't really known... just the current outcome. I think the key thing is time to get it right. Failure is certain if the proper goals weren't set. That is a management issue. At what level is unknown. Either they really knew what they were doing spending the money or were very unwise.
  12. To set the proper perspective, Mooney is now a Chinese company. I'm not stating this as either good or bad... but it is a fact. Setting a goal to "clean sheet" design a new aircraft in the amount of time stated earlier in this thread indicates that the design was never intended for the US market. This "failed" design effort could have simply been an way to measure and mine current US engineering and technology knowledge in the aviation market. It's possible that they really didn't have any idea whatsoever about what they were doing... but that's not likely. It would be very interesting to hear how much time it would take to get a clean-sheet design "certificated" for the US market. The "trade war" hypothesis is a somewhat weak position to take. Mooney was not purchased with the intent of serving the US market. It was purchased for the brand-name and IP. A "trade-war" has nothing to do with any of that. Mooney didn't ask for any opinions from current Mooney owners or enthusiasts since this group was not their target at any price-point. However, if an enthusiast (considering other competing options at the price-point) was gullible enough to pony up the cash for a new one... they were happy to oblige. I don't intent to freely give Mooney any ideas to help the company survive, prosper, or for any other reasons. They've made it clear that they have no intent of serving the market that I'm a part of.
  13. Just how much of a "significant effect" will a 1/4" placement make when the EGT Thermocouple it's properly positioned in the exhaust stack?
  14. Look into how many GPH is being burned at 1250... provided you have accurate EGT probes. EGT values aren't carved in stone. That said, saying they are meaningless might be going a bit far.
  15. Perhaps this is why some have referred to their planes as being their "mistress." Just add money and presto... Stop adding money and no more suction...