Mike Koerner

Fifteen people that I have known personally (at least met and talked to) have died in aircraft accidents. I know it’s fifteen because I have each of their names listed on a spread sheet called “Dead Flying Friends”. A column next to their names describes the nature and circumstances of the incidents that ended their lives. Another column lists their aviation experience: their flight hours, ratings, noteworthy aviation accomplishments and awards. The last column is my appraisal of their flying skills. It’s just a “Yes” or “No” response to the question “Were they a better pilot than me?” Most, I believe, were. I have only known one person, personally, who died in a car accident. Yes, I have known of many people who have died in cars, and I’ve seen some of them by the side of the road (I have also seen some in and around the remains of aircraft). But, except for the one, I did not know any of these car accident victims personally. I have probably known, personally, a hundred times more people who drive cars than people who fly airplanes. Furthermore, the people I know probably drive in cars ten times more often than the pilots I know fly in airplanes. That means flying is fifteen thousand times more dangerous than driving. (Do your own calculation.) I believe that we, as pilots, can affect this outcome. That alone, allows me to continue flying. But it is only true if we recognize, accept, and try to address the problem: Flying in light aircraft is fantastically dangerous. By the way, this method of assessing the risk of flying by comparing it to driving, was originally proposed by Bruno Gatenbrink, perhaps 10 years ago.

FredG, (I hope no one else is still listening) Moving on would be wonderful, but... Density is more properly defined as mass per volume, rather than weight per volume. The mass, and thus density, of the displaced fuel didn't go up with increased g-loads. But its weight, the force that mass exerts due to the g-loads applied to it, did go up.

FredG, You are right. I was wrong. Please accept my apologies. Archimedes said the weight of a floating object is equal to the weight of the fluid it displaces. But weight is a force. It’s not just the mass of the fluid displaced (volume times density), it’s the mass times the acceleration due to gravity. The mass of fuel displaced doesn’t change under increased g loads, but its weight does. And as you said, that increase in fuel weight will be proportional to the increase in float weight. So, under increased G loads, the floats will not sink further in the fuel bowl. I’m going to go back now and add a correction of some kind to my previous statement, not to hide my error, but to warn future readers it is incorrect.

The following statement is wrong and should be disregarded: FredG, You're right, you and Archimedes both, when you say that the weight of a floating object is equal to the weight of the liquid it displaces. However, whereas the weight of the floats is equal to their mass times the acceleration due to gravity (F=MA), and gravity is also acting on the fuel, the fuel is largely incompressible. Under increased G loads the floats will sink further in the fuel bowl displacing a larger volume and weight of fuel.

Even cheaper than Andy's suction cup shade, I keep one of those old fashion paper charts in the cockpit and drape it over the forward spar tube when needed.

Neat.

Wow. That's a very compelling photo. Little Doctor I presume. What months of the year can you get into it on floats? Mike in Kaslo used to send the forum wonderful photos and movies from Kootenay Lake, and Kelowna, and Kamloops. I miss those. You seem to have the local scenery and photo skills. Maybe you can share more of that with those of us lacking in latitude.

That's interesting. When I inquired about getting an LOA for the addition of wing tie-downs for my 2004 CT2k many years ago, FD declined. I'm less interested now as I have developed a tiedown method that I consider quite acceptable. I position the plane with the nose wheel just in front of one of the airport tiedown rings and connect a short, stout rope between it and the bottom cross bar on my engine mount. By holding the nose down tightly, I minimize the angle of attack of the wing. Between that, a negative flap setting and having the stick tied full forward; it would take quite a blow to lift off. That said, super strong lateral gusts could bang up my wing tips. That hasn't happened yet, but if I was ever worried about it, I also carry straps long enough to go over the wings and down the gap forward of the control surfaces, as Roger suggests. Mike Koerner

The relay is probably the heaviest and tallest component on the board. Engine vibrations, and perhaps airframe loads as well, put lots of stress cycles on these solder joints. Perhaps as a prophylactic measure, those of us whose flaps still work should run a couple wraps of electrical tape over the top of the solenoids and around the bottom side of the board, and then a layer of gorrilla tape over the top of that?

I'm with Procharger. A drop of 50, or even 100 rpm, is insignificant. Mine varies more than that from day to day. According to my manual the maximum allowable drop is 300 rpm with a 120 rpm maximum difference between the two circuits. Mike Koerner

It looks like it’s probably a fairly recent manufacturing problem in that it only aplies to 120 engines and the 912 ULS serial numbers are about 4 million higher than my 2004... but I don't know how their serialzation works and you should check for your own serial number anyway. Mike Koerner

Hi Murray, Unfortunately, no one on this forum is privy to the stress analysis relating to the selection of fasteners that hold this bracket in place. However, If the design calls for four fasteners (it does) you can safely assume it needs to have all four fasteners, that they need to be the specified fasteners (by part number or size and grade), that they need to be accompanied by the specified hardware (nuts & washers), that the need to be properly assembled, and that they need to be tightened to the specified torque (or a standard torque for that size and grade of fastener if no other torque is specified). The maintenance manual provides this information. From the photos you sent it appears that the outboard fastener is not the correct part (C9996060 I think), does not have the specified washer (C9996565), and has not been properly torqued (80 in-lb). This should set off a bunch of alarm bells. I would go back through the maintenance logbook and figure out who did this work. I would then very carefully examine every other job he did, or might have done, on this aircraft. And yes, I'm afraid this may be an enormous job. Sorry.

There's a simple hand tool you can use to flare the end of metal tubing for AN fittings... If you have sufficient access.

Corey, We've had different experiences... with different aircraft. My CT2k doesn’t have rudder or aileron trim, just elevator. I don’t rebalance fuel often. It’s only at the end of a long flight, for example when one sight tube shows 2 or 3 gallons and the other shows 5 or 6. My personal minimum is 5 gallons total with fuel showing on both sides during coordinated flight. In a few minutes of fuel rebalancing, I can move a gallon of fuel, gaining some additional flight time and ensuring that I don’t un-port either side while maneuvering for landing. I don’t worry about un-porting a wing during the transfer. As Ed has pointed out, as long as there is fuel against the root of the high wing, it'll should get to the carbs. The “half ball” I’m referring to is on a mechanical turn and bank. With our nearly flat wings the difference in head between a full fuel tank and an almost empty one is only a few inches; vs. 30 or so from the carbs up to the wing. Fuel transfer works for me anyway, but perhaps I shouldn’t recommend it to others.

Though I’m loath to disagree with anything Corey says, in this case I feel so moved. Most of us don’t fly perfectly coordinated. Over the course of a long flight you may find the tanks have not drained evenly. Purposely flying uncoordinated for a few minutes - “half a ball” out with the heavy wing high - is an appropriate means of correcting this situation relatively quickly. Yes, you could just fly perfectly coordinated from then on and this would also correct the imbalance, over time. The problem is this will take so long you may forget what you’re trying to do and revert to the uncoordinated flight that created the condition in the first place. It’s not important that the tanks be balanced as long as there is fuel showing in both sight tubes during coordinated flight. However, if one tank threatens to empty, transferring fuel to avoid that condition is appropriate. Also, as long as there is fuel showing in both tubes, there is sufficient head to maintain proper engine operation.

Flight Design has updated the status of the F4 (https://flightdesign.com/flight-design-f4-aero2023). It will have the new Rotax 916 engine. First flight will be the end of this year with certification in fall of 2024. A cabin width of 134 cm = 53 in. That compares to 49 in for our CTs, an extra 2 inches of shoulder room per person. The fuel consumption of 30 l/hr = 7.9 gal/hr. The range of 1400 km = 755 nm = 870 sm. At a cruise speed of 145 kts that’s 5.2 hr of flight time. Assuming 30 min VFR reserve, that’s 5.7 hrs of fuel. At 7.9 gal/hr, that’s 45 gal usable fuel. At 6 lb/gal, that’s 270 lbs of fuel. A payload of 450 kg = 992 lb. Assuming 4 passengers at 170 lb, that still leaves 312 lb for baggage, 78 lb per passenger, compared to 55 lb per passenger for our CTs. This assumes they really meant to say “payload”. Remember there are translations involved. If they meant “usable load”, with 4 passsengers at 170 lb and full fuel, you would be left with a total of 42 lb for baggage, 10.5 lb per person. 400 T€ = $440.000 at today’s exchange rate.

Well, when you put it that way, it's a hard question to answer. I was just playing around. It makes for a dramatically steep initial climb-out. That said, wheelbarrowing down the runway greatly increases the chances for loss of control. So, I guess the answer is yes.

I think tail strikes come during takeoff - if you hold it on past flying speed and then pull back aggressively.

ditto. Unless you're renting the plane out, I wouldn't worry too much about the TBO (either hours or years). Just get someone familiar with both Rotax and Flight Design to maintain it for you, or at least help you maintain it. I have 2,300 hours and 19 years on my mine with no major work required. And though I've had very competent help at times, I've also done some of the work myself .

This is a damn good idea. I'm surprised I didn't think of it. I found this adapter on Amazon for $19 - free next day delivery with Prime. just keep the torque wrench roughly aligned with this part and apply the equation: M1 = M2 x L1 / L2 Where: M1 is the torque setting of the wrench M2 is the actual torque applied to the nut L1 is the normal length of the wrench L2 is the extended length of the wrench I do think the U-joint style flex adapter I had been using has not been transmitting the torque repeatably. Thanks!

First, as for your legal questions, you might try contacting AOPA. They can at least point you to knowledgeable articles on the subject. With respect to rental, I have idea. All across the country, thousands of young pilots are attempting fill openings Covid left in our commercial pilot ranks. They have their training and licenses, now they need 1500 hours (stupid law). Lots of them are instructing or flying jumpers or tow planes, but there aren't enough of those jobs to go around. So, my idea is: 1) Figure out what your plane costs per hour... and what it's worth on the market, which I think will be higher. I think a CT is a cheap way to fly. It has been for me anyway. 2) Go to one of the active training schools. Ask around. Find one or two pilots that are interested in building time in your plane and form a partnership with them as owners. Again, AOPA can help you do this. The partnership agreement involves not only an equity stake but also an hourly usage charge. The advantage of this over a lease-back is that they are not students. They have instrument, commercial and multi-engine ratings. And their shared ownership gives them a stake in caring for the plane. Once they get their hours they'll want out. Hopefully, you've structured the partnership agreement to allow that, and allow you to go find another partner.

Its hard to avoid over-torquing. e-Props calls for the torque on the standard fasteners to be rechecked regularly. That means I need a click on my torque wrench. I have to use a flex drive to clear the gearbox. Seems like about 1/3 of them turn 30 degrees or so before the click each time I check them. I don't know if they are really loosening or if the flex drive is inhibiting the click some way.

What program is running on the tablet mounted in front of the top center of the instrument panel?

If you don't have instrumentation indicating fuel press, what would be the manifestations of it being too low? Inability to reach full rpm or power?

When working with the wires in the bundle that goes through the firewall, make sure that the wires are protected from the edge of the firewall opening. If the wires rub against the edge, the carbon fiber it will eat through their insulation. Carbon fiber composites are not great electrical conductors, but good enough to short out a power wire and burn.