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The geometry of the satellite system means that GPS altitude measurement is much less reliable than the horizontal position.

Induced drag is the cost of staying in the air, and induced drag is directly related to wingspan. A lifting body is high induced drag, so will always be at a disadvantage to longer span conventional designs when it comes to endurance.

Conserving energy i.e. minimizing drag will be a key requirement for electric aircraft, so I would expect them to be more like gliders with high aspect ratio etc. Look to current motor gliders to get a better idea what an electric aircraft might look like.

I'm sure he does Per hour? By number of registrations? By total number of crashes?

Maybe he meant T tail?

Funny you should say that... Up until recently (a few years ago) the rules were that if a discrete frequency hadn't been assigned, you should use 126.7. Then someone at CASA decided they knew better and things should be how they used to be 10? 20? years ago and issued a CAAP saying that people should be using Area. Various people pointed out that the CAAP contradicted what the rules in AIP actually said. Eventually after a bit of argument about marked/unmarked strips, CASA got the rules changed in AIP to match the CAAP. THEN they issued a discussion paper asking for feedback...

Plenty of people flying into unmarked strips, I guess they are all on 126.7 or not making calls.

Fuel use rate is probably a good approximation of the amount of power and heat being generated. I would wager that you would have trouble using fuel at the Jabiru rate for a sustained period on the bike. Airflow on the bike is probably better than you think. People worry a lot more about cooling drag in aircraft, so low speed cooling (especially on the ground) may be marginal.

I've been to the US a few times recently, and so far have never had luggage lost. On the other hand, the TSA have opened my luggage every time - maybe they are better at putting it on the correct flight than the regular baggage handlers?

Why is there no need for the break free? I am having trouble visualizing how it attaches to the aircraft. Is the torsion block an alternative to the tailwheel spring?

Jabiru are a wet sump engine aren't they, so I would expect all oil lines to be pressurised.

And yet they regularly end up on their back in the middle of a runway after what should have been a routine landing. Or even on their nose during takeoff. Is it just that nose wheel RV pilots are a group of particularly bad pilots? That seems to be the suggestion. I don't actually think it is nose gear strength, I think it is the geometry. From what I can see, the whole gear leg is supposed to act like a spring and flex upwards to absorb bumps. However, the upward arc also requires the leg to move forwards. That's fine for undulating bumps, but if you hit a large enough bump with a sharp enough edge the wheel can't move forwards to roll up and over. Imagine a ramp sloped so that it is at 90 degrees to the angle of the front gear leg. Put it in front of the aircraft so it touches the front tyre. The small wheel and steep angle of the leg means that the contact point will not be very high up on the wheel. Any bump that contacts the wheel below that point is OK, the leg can flex so the wheel rolls up and over. The force from a bump that contacts the wheel at that point will act IN LINE with the gear leg. The leg can't be a spring in that case, it is just a steel rod in compression. All bump absorption must happen in the part of the leg that bends for the wheel attachment - where the first failure is occurring. This will create a bending force in the leg that will try to curl it backwards. A bump higher on the wheel is even worse - the net force acting on the leg is backwards. What is required is a spring that can absorb the bump without requiring forward movement of the wheel. Almost anything would probably do - look at Jabiru nosegear for an example. Have a look around at other aircraft. How many have nose gear where bump absorption requires forward travel of the wheel? Most have gear where the wheel travels straight upwards or even backwards when going over a bump. A flatter leg angle e.g. RV-10 also helps, because it means less forward travel for the same vertical travel.

Nose gear is never the strong point, but is there any other aircraft that ends up on it's back with the frequency of the RV 6-7-9A? I know a couple of aircraft that have had nosegear collapses, I am trying to think if I personally know anyone with an A model who hasn't... (maybe it's me?) According to the report, the video showed the main gear did touch down first (seeing the actual video would be very interesting).

A couple of things about the chart in that report... The VSI appears to be lagging. It shows a descent for several seconds after the altitude is zero so that is unreliable as an indication of the actual rate of descent at touchdown. Airspeed is shown in TAS so IAS might be lower 1.3 times stall speed is a good starting point to determine approach speed, however aircraft characteristics might show something higher is better, e.g. low aspect ratio wings where drag increases rapidly as speed reduces. I haven't flown a RV, I don't know what the recommended approach speed is. It is obvious to me there is a problem with the RV nose gear, based on the number of collapses & flips. They aren't all solely the pilot's fault. I believe there was a RV nosegear collapse on takeoff at Avalon. I like RVs, but would only own a tailwheel RV-6-7-9.

I think the lack of stretch in glass is what gives fibreglass it's strength, so I wouldn't expect good results from a stretchy material.

I'm pretty sure that is the rule for Experimental in the USA, not Australia. In Australia it is much more restrictive. The CASA instrument spells out exactly who can do what, my understanding is that if it is not in the instrument the normal rules for GA aircraft apply (Schedule 8?). In the USA, many of the regular GA maintenance requirements do not apply to the Experimental category. In Australia, the normal maintenance rules apply to Experimental, hence the need for the instrument to allow builder maintenance.

They are the subject of the discussion paper. Because CASA has made a rule that the transmissions must be on Area, due to some ridiculous perception that there is a danger of collision between someone using their unmarked strip and aircraft in cruise.

Fields that don't appear on charts are the least likely to get (or require) a discrete CTAF frequency. The issue is e.g. if you have a private strip and invite a few friends over for a BBQ, what frequency do you use when everyone is arriving? CASA say Area. The rule used to be 126.7.

I have skimmed it, based on the amount of space they used getting stuck into RAPAC I think the result is a foregone conclusion i.e. keep the current changes.

The change already happened, however CASA received a lot of criticism from RAPAC and elsewhere about the change so they are starting a "discussion". The change was simply that aircraft operating at unmarked strips should make their circuit broadcasts on area instead of 126.7 - because apparently people listening on area need to know.

From a societal point of view you're probably right, but they might be the only people keeping the airport open? If they take their money away, all of a sudden it looks easier to the Commonwealth Govt to close the whole airport and sell off the land. Currently you have people with money and lobbying power who want to keep it as an airport - because they are making money from the DFO etc.

Interesting discussion with some town planners, they have no say about developments on the airport. (Because it's Federal land?) The style of development at Essendon would not be allowed in other developments in the same area. That may actually be an incentive to keep it as an airport - while it's an airport the lessee can collect rent and develop whatever they like without planning controls.

I doubt it. That track probably isn't the actual track, it will be created by drawing straight lines between recorder radar points.

I have been told that fuel injection hose should not be used on carb systems, the lining doesn't have enough stretch for some barbed fittings (needs specific fuel injection fittings) and can be damaged during fitting. No idea how likely that is bit I used the Gates Barricade hose for carb systems last time I changed it.

No piano keys on that runway, runway numbers are white on white concrete going by the Google Earth picture. If this works: