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Momentum is a vector. Otherwise, two blocks running into each other on a frictionless plane would have the same momentum after the crash regardless of the directions they were going before the crash.

4) is wrong. Ground speed increases.

No. If you are straight and level into a 30 kt headwind and are 10 kt above stall, and you turn instantly 180 degrees, you are 10 kt above stall

Aeroprakt A22LS Foxbat. It has long range tanks.

Just follow the grey line!

I forgot. The bearing in the rocket box is magnetic. The OzR people promptly replied to an email I sent, and pointed that out to me. It changes with magnetic variation. So, even the rhumb line would be wavy if it was represented literally instread of symbolically!!!

That is a good observation. The quoted heading is for the rhumb line between the two points, and it certainly looks a lot less that 303°

The Distance to Go, and the Distance to Go (Great Circle) are stated as being the same. This is a screenshot from a trip I was planning from Brisbane to South Africa.

So, it looks like a draggy aircraft performs 10% worse and a really slippery aircraft performs 50% worse with the prop stopped vs idling. That makes sense, and is something for me to remember. Thank you for the info.

Pretty much the whole emphasis on airline safety is organising it so that if the crew stuff up the plane still doesn't crash. The crew is dead, so they don't need to be excused. It is no coincidence that modern risk management began with airlines. The usual response after something goes wrong is to punish/sack/sue the person who did the wrong thing. With airlines, the person who would have been punished was already dead, so they needed a new procedure. It is *inevitable* that pilots will make mistakes. At the moment, there are three fatal accidents per million departures. To have an accident rate that low means that systems have to have been in place to pilot errors. I head once that pilots make about 1.3 mistakes per flight. On a separate occasion, I heard a flying examiner say that they had never examined a pilot and found that they made no mistakes. Blaming pilots is not how aviation safety works. Don't get me started on Bowing. Bowing, and the 737 in particular, had a fantastic reputation. I'm not sure how long its going to take for them to get their reputation back, but I can say that my view of Mercedes Benz is still coloured by their period of bad quality in the early 1990's. F-ck you, Mercedes Benz.

Yes.

Units should not be stated as part of formulas.

The above conflates expectation with respect to preparation with expectation with respect to probability. The reason that it is important to expect an engine failure is as follows. It takes about three seconds for someone to respond to an engine failure on takeoff. During that time, the aircraft can go from Vy to below the stall speed. In addition, there is a temptation to pull the stick back. That means that the pilot needs to be ready to push the stick forward quickly. About the probability of an engine failure being "well below 5%". Rotax engines have a failure rate of 15 per 100 000 hours. If you assume that flights are one hour long, and that *all* the failures are at takeoff, the probability of engine loss at takeoff is 0.015%. I got some push back on this forum a while ago when I suggested that RA-Aus flying seemed to be safer motorcycle riding but more dangerous than driving. According to FlightSafety magazine, the former chief commissioner of the ATSB said that private pilots were dying at the same rate as motorcyclists. That means that RA-Aus flying is not a low-risk activity by normal measures. All this means that there is genuine utility in pilots both expecting and engine failure on takeoff, and, at the same time, the same pilots knowing that an engine failure on takeoff is very unlikely.

In the case of the tail, decreased stability would not help in maneuverability. It would decease ability to maintain co-ordinated flight with rapid turns. When maneuvering aircraft vigorously, rudder input is *increased*, so you need an effective rudder. It would not make adverse roll and Dutch roll worse. It would make the aircraft less stable, which would make it less useful as a gun platform. This issue is different with dihedral, where stability acts against the ability to roll the aircraft.

The camo might be so that he is not spotted being where he is not supposed to be - rule breaking.

Contrary to the saying, "There are old pilots and bold pilots, but there are no old bold pilots," I think that there are skilled pilots who are bold. To my mind, this fellow is skilled AND he is deliberately flying in a way that challenges his skill, and is therefor putting him at risk. I didn't notice him pushing a rock out of the way, but I did notice the wind coming from the right wing push some branches out of the way. I have not gone through the list of dangerous flying attitudes, but I do note that having a camouflage-coloured aircraft is consistent with a macho attitude. The bent-prop thing suggests that he does not think that it could never happen to him.

Wrong *again*. There is no angle above which the nose goes which results in a stall. There is an angle of attack above which a stall will occur, but that is a different angle. And *again*. A wing does not have to be stalled to no longer be able to keep the aircraft at a constant altitude. And *again*. Your original post was about physics and now you are talking about maths. You can understand the basics of the physics without doing the maths. And *again*. When you make a post that is about two subjects, it is about two subjects. It’s not like you get to say silly things and then get to have them ignored. When you go around saying that a spirit level can do the same thing as an angle of attack meter, someone might believe you. My guess is that it might have sunk in that you can’t use a spirit level on a stationary airplane to measure the optimum angle of attack, and that it might be sinking in that you can’t use a spirit level to measure angle of attack. So I suppose that’s a plus. But, hey, I can pick holes in other things. Technically, the *subject* of a thread is what the thread is about. The *theme* of a thread is what the thread ends up saying about the subject. For example, one subject of this thread is: discussion of whether or not... One of the themes of this thread is: nope,...

J160 has lower max weight so I would have thought it would stall slower. Sure about the figures? I am NOT an expert on Jabirus.

No. The best angle of attack will be whatever it is when the aircraft is at max weight and is flying at Vx or Vy. Most people would choose Vy as best, when total drag is at its least. This has nothing to do with the alignment of the airplane, although if the aircraft was designed well, they would coincide. A spirit level cannot do the same thing as an angle of attack indicator because the the spirit level cannot take into account acceleration of the aircraft. If a spirit level was useful for determining angle of attack, the people would use them instead of a commercial angle of attack meter because they are far cheaper. Just to reiterate, the best angle of attack is at Vy, where drag is at its lowest. That’s how come Vy is published and airplanes don’t come fitted with slip indicators aligned with the aircraft. The best angle of attack for lift generation is however much lift you need, up to a maximum, at about 14° angle of attack. The position on the spirit level will not show when the aircraft is about to stall as when an aircraft is about to stall, it will likely be accelerating and the spirit level will no longer be accurately reflecting the angle of attack. For example, if someone is recovering from a spiral dive, the aircraft could be 10° pitch up and have an angle of attack of 18° and be stalled. Likewise, if someone is climbing or descending, the slip indicator would not reflect angle of attack. Likewise, if the aircraft was speeding up or slowing down the slip indicator would not indicate the angle of attack. It would only reflect the angle of attack in straight and level flight where the aircraft was not speeding up or slowing down - not the time when aircraft stall. If you want to know when the aircraft is about to stall, you can mark a particular amount of control movement of the rudder (for a particular flap position).

In what way is discussing using a spirit level or a slip (not bank) indicator worthy of discussion about angle of attack? Particularly if said discussion says that they have anything to do with each other. As far as I can tell, OME *still* thinks that you can tell angle of attack with a slip indicator. Also, a slip indicator will not tell you your angle of bank, unless you are not turning. This is just bizarre.

The stall happens at the critical angle of attack (about 16 degrees) regardless of the velocity.

The spirit level won't show you the angle of attack. For example, if you are flying steadily nose up 20 degrees with a two degree angle of attack, the spirit level would show an angle of attack of about 20 degrees. If you were pulling out of a dive, with the aircraft level, the spirit level would probably show about a zero angle of attack, but you might be about to stall. The idea of a spirit level showing angle of attack was so silly, I really thought you might be joking. I didn't comment about you saying you might "write a paper" because I thought that you would just say that you were joking. Looks like you weren't. It seems to me that everyone else is too polite to explicitly correct you. It's not trolling if it stops someone from reading what you write and thinking it might be true, and it's not trolling if you learn that you cannot use a spirit level to determine angle of attack. Experience is not the issue. Things like force and velocity vectors, and mass, force and acceleration are dealt with in high school maths and physics.

The spirit level won't show you the angle of attack.

Okay. If you are flying near vertical, and the airplane is pointing in the same direction, OME's PAAM will show near 90 degrees. If you were flying a little inverted, say at 100 degrees pitch up, OME's patented angle of attack meter would indicate that you were flying a little backwards.

After I did the thrill rides with my eyes closed, I did them with my eyes open. Then, I did them without hanging on. That taught me to not be afraid to trust harnesses to hold me in place. That helped with aerobatic flight, where you have to have a soft touch on the controls and trust the harness to hold you in place.