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A standard circuit is pretty clearly defined in AIP. If you're looking for a particular person, I don't know. I suspect it predates WWII.

CASA is the obvious answer. The main purpose of flying a circuit is to be predictable, and to observe and be observed by other traffic. On base leg, you you should be looking for traffic flying a straight in approach, and also possible other traffic that might have turned base from e.g. a closer downwind. Many aircraft have blind spots in a turn that would make that difficult. Straight legs of the circuit allow you to see traffic that is obscured in the turn. Additionally, AIP calls for a straight final approach beginning at least 500' AGL. The purpose is to allow you to check for traffic on the runway, and to make a stable approach. My understanding of the military initial and pitch is that it helps fast aircraft slow down, and creates separation for landing between multiple aircraft in a formation. It does not seem to be a good solution where you need to fit in with other unrelated aircraft in the circuit.

Performance calculations are often done before takeoff, but it may also be necessary to do them in flight. You don't use the lift equation in the air, but you learn it on the ground so that hopefully in the air you understand the effect of air density, the limitations when you are doing 120 knots in an aircraft with 50 kt stall speed etc.

It is important to understand the effect of air density on lift. It is a critical part of performance calculations. It is also important to understand the effect of velocity - that lift available is proportional to the square of the velocity. Other than that you have wing area (a bigger wing can lift more - not complicated) and the coefficient of lift. The coefficient of lift is just a constant that allows you to tie all the other numbers together allowing for different characteristics of different wings. As for the spirit level: Imagine you are in an aircraft climbing at a 5 degree angle at 60 knots. Now you close the throttle and glide, and the aircraft descends at a 5 degree angle at 60 knots. The angle of attack remains the same if the airspeed and weight are the same. There is virtually no change in the angle of attack from the climb to the descent, but the angle of the fuselage has changed by 10 degrees. The reading on the spirit level will change by 10 degrees - more than half the typical stall AOA - but the real angle of attack has not changed. If it was possible to read angle of attack with a spirit level you can be sure it would have been done long ago - but it is not.

I have been re-reading my info on switches. Switches can have different ratings for resistive loads vs. tungsten loads however the switches that are readily available to us typically seem to list one value. Which value is it? Are we asking for problems using e.g. a 15A switch for a 12V 100W light? Re wiring: - I know the capacitor is not connected to the battery with the master off - even though it remains charged, it can be discharged. - I know the battery is disconnected from the bus and from the regulator with the master off. - I know the regulator is disconnected from the bus with the master off - I know the regulator C terminal is disconnected from the battery with the master off - I think the capacitor remains connected to the regulator B terminal when the master is off - The capacitor does not discharge, so it isn't connected to the C terminal with the master off. The C terminal is the one I am not sure about. The requirements are difficult to satisfy: - needs to read the battery voltage within 0.2V - needs to be disconnected from the battery at shutdown - must not be disconnected from the B terminal while the engine is running or regulator damage can occur The last one is the one that might be a problem for me. I think the C terminal is connected to the bus which means it would be disconnected if I shut off the master. I don't think previous versions of the installation manual were as explicit. I could connect it to the B terminal, but then the voltage would be less accurate relative to the battery because it would be influenced by the electrical load on the alternator. Ideally perhaps I should run both B and C wires back to the battery, and another separate wire forward to the bus. Then they all need some sort of fuse at the battery end...

Sure, but when there are a lot of assumptions it's also worth verifying that the engineering calculations successfully predict what you see in the field. If a tungsten lamp inrush is similar, should we have a soft start for a light switch? It also depends on the wiring - I know in my aircraft the capacitor remains charged when the master is switched off so there won't normally be a large current when it is switched on. I can't remember the details of the switching of the charging system - I will have to double check what is switched.

How likely is that to be a real problem? I have never heard of it in practice. That switch needs to be rated to open a 20A+ DC circuit - is the capacitor going to draw enough energy to damage the switch when it closes?

The installation manual shows 20A at 5000 rpm, and lists the maximum output as 22A. Also, as you point out the capacitor can draw a much higher current from the battery for an instant when it is initially connected. You obviously want to be sure that the fuse won't blow unless there is a real problem, otherwise it becomes a reliability issue in itself.

The diagram is incomplete... we need to see the C regulator terminal and switching to understand the design. Rotax call for a 25A slow blowing fuse to protect the regulator. Since that circuit needs to take the entire regulator output anyway, the fuse between the regulator and capacitor seems redundant. The fuse on the battery side protects that circuit. I'm not convinced that a 25A fuse would provide much protection for the capacitor. My understanding of the capacitor function is: a) the PM alternator output is not very smooth because it comes from a single phase, and the capacitor helps there. Sure, a better alternator might be nice, it might also be heavier, bulkier, more expensive. b) if the battery and load is disconnected, it slows the voltage rise enough that the regulator should be able to respond and cut the output without damage to the regulator & charging circuit.

There are a lot of square inches of wing. The pressure difference required works out to around 0.1 psi for a typical light aircraft.

Would you be able to turn to starboard if the rudder was attached to the extreme port side of the boat? Of course, you would, so it’s not drag doing the job.

No, it's fundamentally wrong. I don't even know which side you are suggesting the lift comes from. Dividing people into Bernoulli and Newton camps is completely misunderstanding what Bernoulli and Newton are about. They are both correct* - they are just different ways of looking at the same thing. It depends on whether you choose to view air as a fluid or a stream of molecules. * Some people - usually those who divide people into Bernoulli and Newton camps - use Bernoulli's principle incorrectly. But that doesn't mean Bernoulli was incorrect.

"Lift on one side" is an inaccurate picture. Lift is the result of a difference in pressure between one side and the other.

I don't understand the question. Of course they produce lift. Drag is an unavoidable byproduct of lift, but the drag does not produce a force in a useful direction (with the exception of odd configurations, like aircraft with the rudder on the wingtips).

27 knot stall sounds a bit too good to be true. Indicated airspeed maybe, but I am skeptical that is the real stall speed.

Where does that put the centre of gravity? That is even more important than the overall weight. Your "confirmation person" doesn't sound like someone who gives good advice.

You can fill in a form for a RPL, do a flight review in a GA aircraft (which could be something like a Jabiru also registerable as RAA, and which also counts as your RAA flight review) and you're legal to fly a C172 (subject to competency requirements etc.) How much less bull do you want?

No. The manifold pressure gauge measures approximately how much air is available in the manifold for the engine. It is a measurement relative to zero i.e. a vacuum. It is an indication of how much air will be drawn into the cylinder in an intake stroke, but it doesn't measure how much is being used. If the engine is not running: - at sea level, the gauge measures about 30 inHg - parked at an airport at 5000', it will read about 25 inHg. - launch your Cessna into space and the manifold pressure gauge will read zero. With the engine running, the gauge will read somewhere in between. The pistons are sucking the air out of the manifold, and the throttle limits how fast it can be replaced. The manifold pressure gauge can't tell the difference between low manifold pressure due to flow into the manifold being restricted by the throttle, and low pressure at wide open throttle because you are at altitude. Nor can the engine.

Manifold pressure is measuring the pressure in the inlet manifold, after the carb/venturi, throttle etc. it is measured relative to zero i.e. a vacuum. It is lower than ambient when the engine is running because the pistons are drawing air out of the inlet manifold.

Colder air at standard temperature?

Yes, the master needs to disconnect the battery because that is the most likely source of enough current to start a fire. The contactor should be as close as possible to the battery. My understanding is that the Rotax uses a permanent magnet alternator. There is an option for an external alternator, but I don't think I have ever seen one.

Just to clarify, which quadrants are IFR only? Too bad if you want to travel in that direction VFR!

I'm not sure what you consider a real war, but the USA has seem many more deaths from COVID-19 than from the whole Vietnam war. In April they had more deaths in a single day than from the entire war in Afghanistan, on multiple days. They are likely to exceed the number of deaths from World War 2 within 2-3 months. The Spanish flu pandemic is estimated to have killed more people than World War 1. So far we have been relatively untouched in Australia but if you talk to people in New York, when people you know start dying things suddenly get real.

It is true that treatments have improved and we know more about what works and what doesn't. But the death rate is still very high. While some elderly people die quickly, for many people it is 3 weeks or more after infection. When numbers are increasing, comparing infections to deaths gives a misleadingly low death rate. Deaths lag infection numbers by 2-3 weeks. We are going to see some bad numbers appearing in Australia over the next week or 2 and continuing for a month or more, depending on the effectiveness of lockdowns.

That's how sore throats and sniffles spread, and it's also how COVID spreads. By the time you have symptoms you are likely at your most contagious. The advice is if you have ANY of: fever chills cough sore throat shortness of breath runny nose loss of sense of smell or taste Don't go to work, don't go out other than to get tested, and stay home until you get the result. People waiting to see whether it turns into something more are why we are ending up with 40+ cases in some workplaces. If you are as sick of this pandemic as I am, please do the right thing and make sure you are not contributing to further spread.