tgardnerh

This part seems risky from a regulatory standpoint--it's removing metal and adding something squishy in an area where preloaded is critical. (see the current thread going on oil leaks and engine cases) Is it something that is within the scope of a&p discretion, or does he have specific approved data to do that? Sent from my iPhone using Tapatalk

Discount Javelin. I don't mean that dismissively--they're highly sophisticated themselves, just a bit less involved than the Javelin and a lot cheaper. (iirc line of sight only, shorter range, no homing, but still very good at delivering a superplastic jet of metal through the top of a tank) Apparently they've been used to unbelievably strong effect. Sent from my iPhone using Tapatalk

Have you tested that with intentionally contaminated fuel? I'm always a little concerned that I won't be able to tell the difference in a gats jar, so I wet a paper napkin with fuel and look for an oily spot once it dries. Sent from my iPhone using Tapatalk

My understanding is that an oil leak is an annoying mess, not an safety issue (within reason). Presumably you have an airplane to fly, especially in summer, so change the gasket and if it works great, otherwise OH the engine when the weather goes downhill (if you are so inclined). Sent from my iPhone using Tapatalk

As a recent emigrant from CA, the fair statement is "California seems incapable of building anything." Apparently Tokyo alone builds more housing every year than the entire state, no wonder it's insanely expensive. And never mind that building density in cities with costal CA weather is probably the quickest way to reduce carbon emissions. Regardless of what you think about CO2, the mismatch between policy and stated goals in CA is stunning. \end{soapbox rant} Sent from my iPhone using Tapatalk

Let me offer my paraphrase of Mike Busch and John Deakin (synthesizing the their separate writings and doubtless introducing my own errors). This will also be a good exercise for me as more knowledgeable folks correct me :-) For a given HP, the closer the mixture is to stoichiometric (all O2 and fuel consumed, none of either left over) the higher the peak internal cylinder pressure, and the hotter the cylinder metal. Roughly speaking egt peaks when the mixture is stoichiometric. GA engines can handle the pressures produced at peak egt at ~65% power or less. The "red box" is roughly the set of power/leanness combinations that generate heat and pressure beyond what the engine is able to handle--which can lead to chronic cylinder damage from too much heat (eg the claim that leaning burns valves), or pre ignition and detonation (which can rapidly convert your airplane into a glider). In cruise flight, if the cylinders are all roughly getting the same mixture, a safe way to operate LOP is to pull the red knob back until power drops, and then push it back in gradually until your hottest cylinder is as hot as you're willing to let it get. (This especially is my paraphrase--don't do this without independently convincing yourself that its prudent!) Note also that when an engine is run "too lean" with catastrophic effects, usually whats happening is that its ROP at takeoff power, but because of a mechanical issue one or more cylinders are not rich enough. I now await corrections! --T Sent from my iPhone using Tapatalk

What was the difference in scope of work and in price between your iran and a full overhaul? Sent from my iPhone using Tapatalk

I'm curious--do you also have a high alcohol tolerance? When I lived at sea level I found 8,000 ft was about equivalent to one beer for me, and one beer is enough that my driving a car would be reckless, both of which I gather are unusually low tolerances. After moving to Salt Lake my tolerance for altitude seems to have improved whole my tolerance for alcohol has further diminished. Sent from my iPhone using Tapatalk

If you listen to the overwhelming advice on the thread and just eat the 2k, then you should also consider asking your insurer for a higher deductible. As others have mentioned, insurance is for the costs we *can't* cover, and I try to have all of my deductibles reflect that. Sent from my iPhone using Tapatalk

All noise aside, file that NASA report asap. Specifics aside, having that receipt will go a long way if you have an uncomfortable conversation with the FAA, both convincing them to use their discretion to be kind, and protecting you from license action if they choose otherwise. Sent from my iPhone using Tapatalk

I wonder how many of the survivors snuck into part of the pressurized area like the cargo hold or avionics bay. (Or were on a piston powered flight that never got that high, since the data goes back to the '40s.) Sent from my iPhone using Tapatalk

I think all-in hourly averages are not great to calculate once you've committed to the buy vs rent decision, because the number we care about is how much the next hour will cost. Based on those numbers, it looks like you're paying about $26k/year to keep the airplane airworthy, and then about $130/hr to fly around. Which is why "cost per additional hour" is always the number *I* emphasize to my wife. Edit to change what part i quoted to match my point better. Sent from my iPhone using Tapatalk

A while back, with maybe 100 hours experience if that, I flew a 152 at gross out of a hot and high airport, and everything went smoothly because this video was the angel on my shoulder reminding me what to expect. Definitely a favorite of mine, too! Sent from my iPhone using Tapatalk

Since KSGR is owned by the government of Sugar Land, wouldn't it be reasonable for them to insist multiple FBOs be allowed to operate there if it is financially viable? Sent from my iPhone using Tapatalk

This is my strategy too (medical D tank, constant flow reg, pulse-ox for finger). I have had okay luck getting the tank filled at scuba shops--usually one in each metro area will do it for ~$20 Sent from my iPhone using Tapatalk

I'll buy that it's clinically no different (and its where I live now, along with a few million other people up here), but I can't see why you wouldn't need to compensate somehow. To drop off the same oxygen in the tissues, you're gonna need either more blood flow, or a lower venous sat (and a lower partial pressure O2 in the tissues to accomplish that). A higher hemoglobin count will do the job too, but I hope your airplane climbs faster than you can make blood. A back of the envelope calculation assuming 50% saturation of return blood means the oxygen delivered per blood volume is ~10% lower if nothing else changes, so then you'd expect about 10% higher bloodflow to compensate. HR will have to go up more if venous sat is higher (because the % change in delivery is bigger), and less if stroke volume can also increase, and there are no doubt a half dozen other factors that matter, but the math pencils out to say that a mildly lower saturation should cause a mild compensatory mechanism. Disclaimer--Not a doctor, just paid a lot of attention when my wife did med school etc. Sent from my iPhone using Tapatalk

Do you also get a boosted hr when you're satting 95-98 without O2 at more moderate altitude? (eg, thats about where I am baseline in Salt Lake at 4,500 ft). Conversely, does your HR come back down if you turn up the O2 until your sat is 99-100%? Sent from my iPhone using Tapatalk

My quick reading of their page and the wiki pages for the cessna caravan and the pt-6 engine looks like they're claiming about 10% less fuel burn per horsepower than whats flying a caravan, but in a smaller lighter package. That seems a little... optimistic. Sent from my iPhone using Tapatalk

Exactly!! All i mean is that however invested they are in your airplane not falling out of the sky over mountains, you probably care even more! If they didn't think there was a serious concern about hidden damage, they would be perfectly happy to have you make the airplane airworthy with just the AD. Sent from my iPhone using Tapatalk

The thing I keep coming back to, in addition to the anecdotes about engines that dialed fine but failed magnaflux (or worse) later, is that the insurance companies *want* you to do the SB. They're paying for the teardown for sure, and they're paying for the crash *if* it happens later (and you're still with them) and they go out of their way to encourage you to do the whole SB, not just the AD. Since they're not in the business of wasting money, and they probably value the life of you and your family less than you do, this seems to suggest that they know something about the relative risks involved. Sent from my iPhone using Tapatalk

I'm curious--did they give any indication of how often IRANs for prop strikes turn up hidden issues (i.e. something that could break later even though the crank dialed fine) Sent from my iPhone using Tapatalk

I think I watched that webinar maybe 3 weeks before this incident. When I saw the crazy-high CHT I more or less heard Mike Busch on my shoulder telling me "pull the power to idle NOW." Probably saved the engine, and maybe even avoided a serious accident.

To close this out: The cylinder came off, and the verdict was that the valve guides and valves were bad, the cylinder barrel was polished smooth, and the piston was scored on the sides (presumably from contacting the cylinder, and also badly pitted (I presume whatever was going on in there eroded that aluminum pretty fast). Since then, I also had an event that has been tentatively diagnosed as a stuck carb float, but manifested as partial power loss over mountains. I put the airplane down on the nearest airfield, and found blue staining all over the nose-wheel. All this, combined with the fact that every new mechanic who looks under the cowling says something to the effect of "ehh, i guess it's airworthy," means that if anybody is in the market for a 1/6th share of a Cessna 152 based at KSQL, I've got one for sale. Thank you everybody for helping me navigate this adventure!

I couldn't agree more about the "oh crap" reaction. I had an event a few weeks ago where I had to abruptly pull power to idle 3 minutes after takeoff, and it was 100% my glider rope-break training that got me home safe. There's really no time to make any decisions, just time to execute the decisions you've already made. A bit of tape on the ASI is a healthy reminder that you decided long ago to keep the speed up even if that means landing short.

@carusoam, I did see those notes, though the time for conservative management has past (in the sense that the cylinder is currently sitting on a workbench, which sort of precludes the "gather more info first" strategy). As of now, the #3 cylinder is either getting OH'd or replaced. The plan is to also check the other 3 cylinder head covers for the oil sludge we found on #3, and check all 4 compressions, and check the timing (spark plugs have already been checked for fouling). Once the airplane is whole again, I'll set the JPI to record on a 2 second interval (quickest possible), and upload proper Savvy profile recordings for the first flight, and another flight once the cylinder is broken in. If the mag checks then look off, I'll check plug resistance. Is there anything else you'd do in my shoes? To everybody who has chimed in, thank you! The collective response here has been incredibly helpful. This is a side of aviation that PPL training just doesn't cover, and I couldn't ask for a better crowd to help out with the "Oh shit, now what?" questions.