A64Pilot

We tested every wing tank at Thrush after manufacture of course. We used a home made water manometer connected to the vent line and the air pressure line to the fuel inlet. Advantage of homemade water manometer is it was just a clear plastic tube in a U shape filled with colored water and a ruler on one side. If you accidentally applied more pressure than you wanted it would just blow the water out and of course the air would then free flow, you couldn’t bust a tank. Many home builders here use a balloon, idea being too much pressure will blow up the balloon. Balloons are cheap and easy. Not as precise of course. The home made water manometer was so precise that you would see pressure build as the morning warmed up by just a couple of degrees. When we built the Military aircraft with hard points that penetrated the tanks we had more leaks, we switched to testing with helium as helium is a smaller molecule and will leak more than air. Ask NASA how hard it is to keep helium from leaking, Boeing anyway.

A few comments First be extraordinarily careful doing a pressure test, Gulfstream used to have a G-550 I think it was behind a curtain in their completion center, a mechanic made a mistake pressure testing a wing and ruined the wing. The area of a fuel tank is huge, even just a tiny pressure over such a large are is enormous force Second I’m convinced that fuel when warm will hold in suspension quite a lot of water, then this water can come out of suspension at altitude and cause problems, but it wasn’t there on the ground. Military before we could refuel the truck had to do an “Aqua Glo” test, if the water was above the threshold, they had to recirculate the fuel through the filter that was water absorbing, it would absorb water that was dissolved in the fuel until it was below the max acceptance point. I don’t think that’s done in the civilian world? Lastly My C-140’s factory fuel vents are two 1/8 holes in the fuel caps, of course rain will get water in the tanks so you must cover them. Two problems, cover must stay on in the wind and being on top of the wing it’s possible you may forget them. My answer was to buy two cheap red rubber toilet plungers, unscrew the handle and simply place them onto the top of the caps, they are heavy enough the wind won’t blow them off and if you forget them, being rubber they won’t hurt the tail etc when they fall off on takeoff. These things, cheap and easy

Not really, you think you can but ask anyone who has been through basic training if they have ever been that motivated in the civilian world, for me WOC “Warrant Officer Candidate” training made basic look easy. Air Force and Army “real” Officers it’s a lot more laid back. But the biggest difference I think is in the Military and I assume Commercial world, it’s your Job, the thing that you have to do well in as it brings home the bacon, buys shoes for the Baby etc. Then add in that you get up in the morning thinking flying, majority of the day is consumed by it and nights are spent studying and memorizing everything about it and the aircraft. There is just no way anyone with a real job could possibly put that number of hours per week into training, not and have a job anyway or actually a family really. There is no change the mindset when you get to the airport. The entirety of your life if you will is flying and training. I was Married and had a kid, but did not live with them, I lived in a Military Barracks, at some point I was allowed to go home on the weekends I think as long as training was going well, but I don’t remember when that was.

I was Military trained as well, but we cannot compare Military training to GA civilian training. It’s not so much that the Military pilots are “better” they are most often younger and much more highly motivated and those arguably make them more trainable. It’s their Job, no other distractions, my training was classroom training half the day and the flightline the other half, if we had a weather day, we flew the weekends to make it up. Civilians have a job that’s primary usually, they train and fly when they can, maybe a couple of times a week, plus their instructor is their employee, if they don’t like them they can get another, you take a checkride when you and your instructor feel your ready. Military isn’t like that, you checkride upon reaching the syllabus hours, fail just one and as a min you don’t graduate at the top of your class which means you don’t pick the aircraft you fly as a min. fail a couple and your out, in my case that meant staying a Sgt and back to being a mechanic, not the end of the world, but certainly the end of the dream, part of the motivation. So most civilian it’s a hobby, paid for by that job that they spend a min of 40 hours a week at so they can afford to fly. Military it is their job, so they can spend every day, all day training.

I got my fixed wing transition and Commercial / instrument at Central Tx College in Killeen Tx, as it was a degree producing program it made it easier for me to do while active duty. Anyway the purpose of that school was to produce Airline Pilots not Mooney drivers. According to them most or nearly all Airline type aircraft get approach flaps, not gear first, so therefore they required flaps first, then gear, which means of course you had to slow to 111 kts, put in approach flaps, then get gear. It’s easy to do if you plan it, but you have to plan ahead, you’re not making the approach if you hit glide slope intercept at 130 kts for instance. I have zero experience with the big iron, but bet they are similar I bet they have to start slowing well before the approach. I’m also convinced that at least for the aircraft with lower gear doors that slowing before dropping the gear is easier on the actuator and the mechanism, as is retracting it at as slow an airspeed that is safe to do so.

I think it was me, but her job is not to ask, but to make sure, Verify gear down is I think an important distinction from gear down and I have her verify by looking at the floor, then she gives me a thumbs up, of course I’m checking too, but her doing also makes I think it less likely that both of us forget. Obviously I often fly without her, Wednesday lunch for instance so you can’t rely on the other person. I also installed a daylight white LED in the floor indicator that’s a lot brighter than the incandescent so it’s really easy to see the marks, with the old bulb in daylight it was difficult at best. To continue everything stops when I get the gear, by that I mean I do nothing, checklist stops until I verify they are down, flipping the switch for many satisfies mentally the requirement, but i’ve changed that to verify gear down as opposed to gear down in the checklist. May seem picky but I know the day is coming when I put the switch down and nothing happens

Your one of those guys that thinks their car gets better milage at 80 mph than 55 aren’t you? I’m just teasing but I’ve run into many that believe that. I wish you were correct, but your not, unless your so slow your in the region of reversed command any additional speed of course requires more power which requires more fuel and the fuel required exceeds the speed increase percent wise, so the MPG goes down. Unfortunately you can’t increase fuel flow by say 20% and go more than 20% faster, I just pulled 20 out of the air, use any number. I know what your thinking, that there is an efficiency point where the the fuel required to make horsepower has a peak, that is a point that the engine is operating at its greatest BSFC and your correct, there is, but unfortunately that small increase in efficiency is more than wiped out by the larger increase in drag from going faster. I have no idea at what RPM our motors peak at BSFC wise but suspect due to frictional losses it’s lower than 2500, add in of course prop efficiency and it’s peak is definitely lower than 2500. I don’t have an RPM number but suspect it may be the bottom of the green. Turbines are often different, they are so inefficient at partial power that sometimes going faster will increase range because they are so much more efficient at higher power, but piston engines aren’t that way.

I’m sure it was sea level or lower, maybe a polished airframe, bare bones equipment, 5 gls of fuel on board and a 90 lb girl flying. Ailerons may have been reflexed a little, And maybe just a little wind behind it

Define efficient. Your MPG will go down but your speed will increase if the only variable is RPM.

From memory when I bought mine I went out and did a three way speed run and got 167 kts at 1000 MSL. WOT and 2600 RPM I was also burning right at 20 GPH though. 8.35 MPG and I’m certain not real good for engine longevity Back down to 23 squared and pretty deep LOP gives me 16.88 MPG at 135 kts at 1000 MSL I can further reduce to 22 squared, 6 GPH at 20 MPG, but can’t stand that and it’s tough to keep cyl head temp in the green Legend Cub as a comparison cruises 80 kts and 6 GPH for 13.3 MPG. Amazes me that we burn far less fuel than a Cub MPG wise.

I’m betting it’s a crack, I don’t see any carbon build up, I see carbon build up beside the suspect area though. I’d be more interested to know if that crack even really matters though

That varnish build up the dip stick on that Bonanza makes me think it may not be fine for your engine, but that possibly will take hundreds or thousands of hours to manifest. If there was going to be a problem with the G100 fuel I didn’t expect them to surface for a long time as none of the testing I’m aware of went for years and to TBO, I was very surprised several surfaced right out of the gate. I’m thinking the formulation of what’s being sold is different than what was tested, I theorize that the formulation is sort of loose meaning pretty wide tolerances in percentages of each component or possibly allows different formulations with I assume Octane being the driver. But that’s unfounded speculation. I don’t see how you can fix the problems myself, what kind of fuel cells will survive it, or are we supposed to accept say a five year or less life of cells and tank sealant, paint etc. I think it’s going to start eating boost pump seals and every non metal part it come into contact with.

I retired from the Army in 2003, the Army and I assume all services seem to adopt the latest and greatest processes and materials, for instance we were using teflon hoses when I first came in in 1982, replaced 5606 with 83282 etc. ‘As of when I retired even the then new AH-64D still used Buna-N O-rings throughout. I first used Viton in cave diving in I guess 2105 or so, never seen it used in Aviation until I saw some crop duster gate box seals that were Viton, and that has nothing to do with aircraft engines etc, I’m sure Pratt & Whitney still used Buna-N as of five years ago. I think Viton’s use in aviation is rare from my experience.

My CFI did that to me 40 years ago in a M20 AT, I’m sure that was school policy He got me too, really made me think.

I don’t believe they had all these issues and forged ahead. Even if we assume he knew of the problems, he’s smart enough to know they would surface very quickly once the fuel hit the street. Only way I could believe even a dishonest person would do such a thing is if they sold the rights etc right after obtaining the STC. Which of course didn’t happen, so I’m at a loss to explain. ‘I am not saying, implying etc that there is any dishonesty going on. Only think I can come up with is that there is some kind of difference in the fuel being sold and the fuel that was tested, or some other difference in storage, environment etc.

Leads one to question then what the scope of testing and field trials were then. The relative sample of aircraft that are now burning the stuff is small, yet there are serious problems. Is it something about California then? One or even two aircraft I could understand being outliers, there will always be a very few problems with anything new, bugs to work out etc. Try as you might to manufacture the perfect product usually something pops up once it’s out in the wild that didn’t show up in testing. But there have been a slew of problems in a relatively small sample of aircraft, not just one or two bugs, but big seemingly unsolvable problems, the fuel selector valve issue on the twin Cessna is unquestionably a safety of flight issue. That could probably be fixed by Viton if it were part of the STC, but not every O-ring and or incompatible material can. I’ve not seen Viton seals for example, surely they exist. but Viton has a higher durometer than Buna-N will it cause wear on boost pump shafts for instance? What’s the basis of approval for substituting Viton for Buna-N in everything? Apparently according to the Eagle fuel cell guy the fuel cells in my Mooney are made from Buna-N, if they swell by 60% if nothing else they won’t fit in the same size compartment, this will lead to I’m sure wrinkles, wrinkles trap water, I learned that in my C-210, engines won’t run on water obviously. But just going off of a gut feeling without supporting data it’s my belief that anything that seriously causes materials to swell is degrading the material in some way. This stuff eats two part polyurethane paint, the Army uses two part polyurethane paint as CARC paint, Chemical Agent Resistant Coating, anything that “eats” two part polyurethane paint is an aggressive solvent. The varnish on the Bonanza’s dip stick would have been more than enough for me

Pretty sad that it takes an interested citizen to do testing that the FAA should be doing. What will it take to get them testing? If tests show negative results in one day, surely they are easily replicated? I understand how Political pressure on any Government agency is enormous, I saw it and had to deal with its aftermath with the G-650 Certification crash, unfortunately they had to kill people in order for action to be taken. Is that what it will take here, deaths?

The statement of lower RPM is “better” is true, everything he stated is true. However it doesn’t make a whole lot of difference. Go out and do your own testing to see, set a target airspeed, then manipulate throttle and RPM to achieve identical airspeed and write down fuel flow differences. I’d suggest to start with low RPM as if you start with a higher one you may pick an airspeed that isn’t achievable at lower RPM. As an old A&P /IA/ pilot my opinion is something near the middle part of the green arc is best and I pick an RPM that the engine is smoothest feeling, for me in my little 4 cyl that’s 2300. Of course if the primary driver is speed, max continuous RPM will be the fastest as usually if you want to go fast, you’re at altitude and either at WOT or max allowable continuous MP if boosted. From a smoothness and helping make everything last longer as in avionics / airframe and engine I think one of the best things you can do is have your prop balanced to the lowest achievable IPS. You’re really balancing the whole rotating assembly, prop and engine combo. It even slightly makes you faster and burn less fuel, because the energy that used to shake a couple of thousand ponds of airplane is now producing thrust (conservation of energy). But it’s not much different, pretty much in the noise band if you graphed it, other than cost there is no downside to a balanced prop. Oh, and if engine longevity is a concern there has been a preponderance of evidence for decades that lower power settings significantly increase engine longevity, for instance Lycoming has written in a couple of pubs that for max engine longevity to cruise at 65% power or less. Implication is I believe that even less is better

Unless lateral CG limits are in the POH, they don’t exist. Some Military aircraft with external loads may have lateral CG limits but those are the only ones I’m aware of, but there are a great many aircraft I know nothing about too. I personally don’t switch tanks as often as I guess most do, I pretty much burn a half tank then switch, haven’t had any real problem doing that.

Sodium filled valves have been around for a while, the engine in The Spirit of St. louis I believe had them for example. https://airandspace.si.edu/collection-objects/wright-whirlwind-j-5a-b-radial-engine/nasm_A19791508000 Most valves are two piece that is the head and stem, often if there is a failure it’s at the joint, most often a failure results from the piston hitting the valve, as they aren’t aligned this bends and sometimes breaks the valve, on aircraft I believe the most common reason for the piston to hit a valve is a stuck valve, very rarely I guess it could be a broken spring etc. ‘The piston staying in one piece is rare I think, often it gets broken, rod goes through the crankcase and of course the engine stops, if yiu break a valve and the engine keeps running, buy a Lottery ticket, because that was your lucky day.

Saw someone do all of his training and get his Private in a C-210, which in my opinion is “more” airplane to handle than a NA Mooney. Guy wasn’t stupid apparently, quit flying before he killed himself and or his Wife. I figure something happened that scared him. Neighbor has a story of a wealthy friend that bought one of the last Mooney’s to learn in, Acclaim I think, turbocharged, had long range tanks put in it to learn to fly because he could make his business trips in it, had to pay someone to go along apparently due to insurance. Got his PP, I guess got enough hours so he could go alone, quit after his second gear up, reportedly saying he had been thinking that if he was forgetting the gear, then likely he was forgetting other things too, that would end up killing him. There is a time honored step program if you will that has you starting in a C-152, now 172, but gradually increasing in complexity and performance, getting your instrument etc., then graduating to a complex aircraft. It works. Look at WWII Military training, they started in Cubs, then moved to Stearman’s, then T-6’s, getting their instrument training somewhere along the way before their tactical aircraft, and we were in a hurry then, killing a few extra pilots was acceptable if it got them in theater quicker. In my flight school I flew four different helicopters before transitioning into the AH-64 In my opinion the biggest reason the Bonanza got the moniker of Dr Killer wasn’t really the airplane, but that the Dr’s back in the day had the bucks to buy one as their first airplane after getting their PP, same I believe back a few years for the Cirrus. That big jump in complexity and speed killed them. Sure some 16 yr olds Daddy’s buy them a ZR1 Corvette that don’t kill themselves, but many do. Most of course would never consider buying a kid a ZR-1 as their first car, but think a complex airplane is OK as a first airplane? So sure some get a Mooney right after their PP and don’t hurt anyone or gear up, but many do, so many in fact that their insurance rates reflect their greater propensity to do so. Insurance companies are experts in risk assessment, do whatever is necessary to keep your rates low and I promise you that you will be a safer pilot for doing so.

I hope anyway. My Wife often flies with me, I brief her that she has one job, to ensure I put the gear down, and to look at the lines on the floor to ensure they are aligned.

I concur distractions are probably a leading cause of accidents, another is complacency, the idea that I fly complex Jets or Military aircraft for a living, this little piston popper I can fly in my sleep. However I know that when I was first starting out that I was much more easily overwhelmed by events than now, being overwhelmed is a distraction, getting target fixated on the airspeed indicator because your having trouble landing for instance

I think I covered SLOJ didn’t I? However if there was a crew of two, there almost certainly wasn’t then that would make forgetting extraordinarily unlikely. There was I’m sure two rated people, but they weren’t operating as a crew, or the non flying one would have caught the gear. Second guy was a passenger I bet, actually I bet no duties were even discussed. I understand the whistling past the graveyard, this section of the forum is full of it, it’s part of normal behavior, it’s the reason why you can get infantrymen to charge a machine gun for instance, the belief of it won’t happen to me. Anytime someone posts about an incident etc on here almost immediately people post why it won’t happen to them. Again, normal human behavior. However insurance companies mostly operate on statistics, if your insurance quote is high, might consider why. I know about age 70 or whatever it is I’ll essentially become uninsurable in a complex aircraft, the fact that I’m Commercial /instrument, over 10,000 hours won’t matter. I’ll likely sell the Mooney then not because lack of insurance is overly concerning, the Mooney is the only airplane I’ve insured, but because they likely have a point. I’m paranoid as hell about forgetting the gear, it’s the reason I insure the Mooney.

I don’t know the stats, but bet it’s three groups, very junior, the old farts, and the person who rarely flies. Very Junior to me is the guy that “I just got my PP and want a Mooney” and or the person who buys a Mooney as their first complex airplane. If you look at these gear ups it seems to be pretty common that many occur soon after being bought. Insurance people aren’t stupid, if your insurance quotes are stupid high, that should be a clue that maybe you need to gain experience first or that you’re too old etc. What’s wrong with renting until you get 100 hours or whatever insurance wants? Old fart is sort of self explanatory, but admit people lose cognition at different rates as they age, but we all lose some. I hate growing old, I don’t recommend it. The person who rarely flies is sort of self explanatory too I think, I fly every week, usually twice or more, but it’s easy for me, I’m retired and the airplane is at my house, when I was working the last couple of years my airplane was over 20 miles away so I didn’t fly much, except I flew for work just not my airplane. I understand though that someone who works and the airplane is an hour away etc it’s tough to fly.