EricJ

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About EricJ

  • Rank
    Senior Member

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  • Gender
    Male
  • Location
    Scottsdale, AZ
  • Reg #
    N201TS
  • Model
    M20J
  1. Small confessional: I did this of necessity a few weeks ago due to, we believe, water contamination. I start the gear up at positive rate and climb between 80-90kts (basically Vy) until the gear is all the way up. In this particular instance just as the gear completed the up cycle and I was pushing the nose over to accelerate it felt just like a check pilot reached over and pulled the throttle to idle. There was zero power...I cycled the throttle to verify no response, noticed that I had a *little* bit of runway left, pulled it to idle, got the gear coming back down, got the flaps coming down the rest of the way and just barely got it slowed enough to run off the end of 25R onto the A4 taxiway at Deer Valley. The tires were squealing a little as I turned that corner onto the taxiway. I'd have been paying for some runway lights if I hadn't made the turn. 25R/7L is 4500 feet long. If it was 20 feet shorter I'd have been off the pavement into the dirt, and that was using the taxiway for runoff. It wasn't stopped until I was well off the runway on the taxiway.
  2. Tires: Air vs Nitrogen

    I have an advanced degree in engineering, and I've done as much damage on this as I can do.
  3. Tires: Air vs Nitrogen

    Any thoughts on why high-temp apps tend to use N2 in tires? One thought I've heard is it's easier to keep N2 dry, but I don't know if that's even the motivator.
  4. Tires: Air vs Nitrogen

    That's for ideal gases. ...edited to reduce potential confusion a bit... Not as much. Non-ideal gases behave to (approximately): PV=znRT where z is the compressibility factor. N2 has a favorable Z. I think it is used in airliners due to the extreme temperature change possible under heavy braking. If you've ever seen the vids of the destructive brake testing that Boeing does, letting the tire last a bit longer before it explodes is a safety advantage. I don't see it as an issue on a GA airplane.
  5. Tires: Air vs Nitrogen

    The Nitrogen fill argument comes up with race cars all the time, too. A big argument in that application is N2 doesn't expand from heat like many other gases do. Since control of inflated pressure after the tire gets hot (from friction) is critical for handling setup, this can make a big difference. e.g., if I'm shooting for 40psi hot pressure, I may use a 32psi cold temp expecting an 8psi rise on the track as the tire heats up. The guy with N2 just pumps it to 40 and leaves it. Much of the pressure increase with air is due to humidity, though, and if I pump more humid air in there than I expected and wind up with 42 or 43psi hot pressure instead (due to the expansion of the additional water), I may have just given myself a significant disadvantage. Some of us just use driers on our compressors and not worry about it too much. For CB racers that store their race tires inflated, the O2 migration (from the inside to the outside) will slowly harden the rubber compound of the tire (which results in less grip). On an airplane, especially with tubed tires, I don't see this as an issue. Airplane tires make very little grip compared to a race tire (and GA airplane brakes suck), so I don't think the difference would be noticeable to anybody. CB racers that are more serious just store their tires deflated to avoid this. I seem to remember reading that the SR-71 had N2-filled tires for the same reason. With a target pressure over 400psi they didn't want the tire pressures to go up and risk a blowout as the airframe and tires heated up at cruise. Very large, heavy airplanes with big tires may have tighter tolerances on desired tire pressure, and using N2 would help reduce the tire temperature as a variable for target tire pressure. I don't think any of these issues are much of a concern for GA aircraft, but N2 fills certainly don't hurt anything. If you check your tire pressures reasonably regularly, or at least do a visual inflation check, you're probably already getting the same advantage that an N2 fill might give. And N2 won't really make much difference on leaks. With tubed tires, I don't know how it would have anything to do with corrosion, either. Just my dos centavos. It is just interesting to me how this keeps coming up in different places. I'm sad for the people who get talked into paying extra to get N2 in their car tires.
  6. ADSB Tracking

    Flying back from Lake Havasu a couple weeks ago, my tablet lit up when we got back to the south Phoenix area.
  7. Had a partial power loss taking off at the home field on Sunday. Was able to make it around the pattern and land. One of the city trucks followed me to my hangar and had me fill my name and phone number on a city airport incident report form. Fingers crossed that that's the worst that it gets for me.
  8. Fuel Tank Reseal - Expensive...

    Some Cessnas have sealed tanks, some Cessnas have bladders, and some Cessnas have modular aluminum tanks. I think 310s have bladders, but I'm not sure about other low-wing Cessnas.
  9. pattern etiquette question

    A lot of the agricultural guys don't use the radio at all, so you have to really watch out for them at fields where they operate. It often seems that they're like the banner guys, they're usually really good at getting in and out very efficiently with minimal fuss. Like many people, going into untowered fields I'm unfamiliar with I'll just listen to traffic and use the same active runway and generally just do what they're doing. At a field with crossing runways I did this and didn't realize the only reporting traffic was a helicopter and I kind of rained on his training parade by using the same runway he was using, when the fixed-wing traffic was actually using the other runway.
  10. I think the gear motor on my airplane is getting tired, and if I let the airplane accelerate too much it may pop the circuit breaker on gear retraction. If I get the gear up early (positive rate, no obstacles), it's easier to keep it at Vy and keep the gear motor reasonably happy and then once the gear is up drop the nose a bit for cooling, cruise-climb, whatever. It doesn't ever pop the breaker if I do it that way. My gear comes down faster than it goes up, and I have *cough* demonstrated that I can gear the back down in time to land on my home field runway if I really, really need to. In the Arrow I used to fly, the gear came up sooooooo slooowwly that I used to leave it down until I was completely out of runway or easy landing possibilities. But it didn't have a problem with either accelerating easily or bringing the gear up at cruise-climb, so that also helped.
  11. My new jacks with built in safety stands

    I went in a whole different direction when I read that.
  12. Oxygen Refills- Robbed

    Typical dive tanks hold compressed air at about 3000psi, not O2, or other esoteric mixes that are not appropriate for aviation use. I'm not surprised they wouldn't touch it. The applications are very, very different.
  13. Century IIb

    I enjoyed my forty-year old Century III for a couple of weeks, and even figured out that although the alt-hold didn't work, the pitch hold did, even though my electric trim is inop. Until it all didn't. Now it just wants to turn hard left all the time and the pitch control is dead. I haven't had a chance to start debugging it yet, but I *really* like having those functions working.
  14. Fuel Tank Reseal - Expensive...

    OTOH, my A&P/IA says that once they start needing to be patched it's often an endless chase of repeated patches. That said, I'm keeping my fingers crossed that the patch that Maxwell did on mine in August is the last leak for a long time. If not, I'll schedule a trip to Willmar.
  15. Best home study ground school?

    I took a thirty-year break and came back into it by going through King's Private Pilot ground school, which helped me get back up to speed and learn everything that had changed, etc.. John and Martha are the OGs of GA, for sure. They are quirky and kitchy, but they are also very thorough and very clear and straightforward. I found their program very easy to navigate and very helpful. That said, I never tried any of the others, so I've no idea how they compare. But now whenever I see John or Martha in anything, or reading their articles in Flying, I feel like I know them.