antonts

never go to sea with two chronometers. Only with 3 or with 1. Mt Erebus case was typical stoneage computer-human interface problem. Big computer somewhere in office gave big list on numbers - humans, take it and obey! No one ever can check it, it is absolutely out of anybody possibilities, even with detailed map and plenty of time. So in reality pilots rely on company experience - "we did it 10 times by these numbers, nothing changed since, so lets fly 11th time the same way!" - not on computers, maps and other instruments. Lucky in 40 years passed we can get not just numbers and abbreviated names but full, detailed and live moving map with plotted flightplan. In seconds. Beforehand and on the spot, on cockpit display and wrist watch, and without any interpreting errors at all. Planning errors are still possible, but at least they can be visually detected.

the very idea of modern instruments is to remove this "trying to talk" at all. They do not try, they do talk. They show synthetic picture and full 2D (or even 3D) situation, live map and filtered by criticalness engine data, they do not simplify the message just to be able to say it with couple of needles and drums. It significantly reduces perception errors which can be up to turn to the wrong side with classic DI or compensate nonexisting bank with cuckoo clock-style AH. Of course it requires to grow with this idea, which appeared only 30 years ago with personal computer progress. It requires absolutely different approach to man-machine interactions, and can not be taught in one week. You must live for long in this virtual world, not just try to augment your senses with instruments like it was before - humans can not filter such a huge information flow, so you have to use it in full, as main source, or you obligatory miss something and as usual it will be the most vital part.

Not. Everybody has to go thru all this nightmare!

typical behaviour of electrical high-pressure fuel pump without primary (feeding, lowpressure) pump or gravity feed. Dry run kills them very fast, and there is very little sucking if output (high pressure) is full of air. Especially risky if petrol evaporates due to heat, it never pumps out all these air bubbles and sometimes stops even by itself as it creates petrol vapor bubble in sucking line. Many years ago I had it on my truck with homemade injector modification with freestanding petrol pumps under frame, not inside tanks, where they had to create some vacuum to suck petrol. As temperature is above 35 and tanks are close to empty it could stop any moment and required to drain air from high pressure line, so finally I installed special electrical drain valve there.

1000 instead of 500 from SH to Maroubra does not change anything - anyway you have to ditch there.

hmmm - it IS so? 1000 V1 North (up to South Head) and 500 only from South Head to Bundeena?

In general case - not. There are two variables - speed and height, both affect vertical speed and interdependable between each other. So the same zero vertical speed can be achieved with given mass, power setting and trim with full range of height and speed, it depends on miriads of conditions (design, temperature, current air pressure, weight balance etc). It can happen that only height increased and exactly compensated reduced weight with decreased drag, but it will be the same event like to win a lotto. May be it is possible to build a plane which has stable speed in some more or less narrow range of conditions (range of power, range of trim, range of pressure, range of temperature etc), but no one will care to do this - trim is specially designed to do the task, no need to embed such a thin interdependencies in design itself.

my instructors do it namely this way. Of course not on flare, just on final, up to runway threshold - and afaik no one crashed due to this approach, moreover it significantly stabilizes finals for unexperienced students as it absolutely separates speed and attitude control. Throttle adjusts only speed, stick upkeeps course (landing point) and attitude.

and especially funny it was to heard from ATC - "Bankstown is closed due to plane accident, no info for how long" - flying nav exercise somewhere near Goulburn. Lucky they sorted it out in time, opened 11R 11C and we landed as planned, not somewhere in Camden. And next day (Sun 4th) - again! Someone damaged wheel and got stuck, so 29R was "closed due to disabled aircraft", and again I am in the air! But this time they closed only 29R.

land surveyors, mine marksheiders, construction engineers etc always use TRUE direction - all maps are in TRUE, as in TRUE there is no need for any correction with position and time, and it works even if you do not have any earth magnet field at all like in deep underground mine surrounded with iron ore. For more than 100 years everybody uses gyrocompass, not as we all know on planes, but ground-linked, with weight pointing down by gravity and self-alighning with Earth rotation vector (axle). Very simple device, but it allows precision up to centimeters in several kilometers of underground tunneling.

usual problem is not he enemy, just not to be on the opposite sides with guys who build and own gps, it is simple, but from local governments. In centre of Moscow all car GPSes show noncence (total mess or Vnukovo airport) due to intentional local signal override around the Kremlin.

yes, right. Without SA GPS gives 5m accuracy after all filters, so the point constantly drifts 3m. And if we use these points to count differences - we receive nonsense, as drift (random error) is comparable to measurement (the same 3m of track per second). But - experimental fact! - 2m/s, walking pace, is perfectly determinable and measurable on usual modern userlevel gps (mobile, bracelet etc). And this is not a result of filters, because it immediately changes value when you turn or accelerate. It simply measures Doppler shift and knows where are the satellites - and it allows to derive speed vector without even determining the position point. But it works only with some velocity, 1m/s usually is on the edge.

[quote="Garfly, post: 570843, member: 2534" Doesn't that give us Track as opposed to Heading? How can the GPS know which way our nose is pointing? yes, track of course. I always think about land applications where they are the same. if you do it in uni lab in year 2000. If you recount speed this way every 1 sec with velocity 2 m/s (so shift is 2m) and average precision 10m (ie every point will be jumping +-couple of meters at every measurement) what you get? Yes, total nonsense. Thats the reason why no one real gps uses this ever. Take your mobile and try it walking with any app showing gps realtime data - speed, bearing etc - especially if it allows to set measurement time interval. If you are moving speed (vector) will be rather precise, regardless of measurement interval etc, because it is directly calculated at points, not as differences between them. Moreover, walking speed (2-3 m/s) was reasonable measured even 20 years ago with SA GPS restriction, when position constantly and randomly jumped 20-50m and difference method gave total mess.

GPS directly calculates position (point) and speed (vector), so to get heading you need just to move somewhere. It means speed vector is not "point B minus point A divide by time spent", it would be terribly unprecise, but directly derived from received signals thru measuring Doppler effect. In case of compass velocity is not relevant, but vector direction gives the heading. 2 antennas required only if you want to get direction data without any movement, in this case it determines positions of 2 points (antennas) and can derive vector direction between them.

Bunnies. Aeros on 200ft, where they had no possibility to recover if something goes wrong. True Russian way, with true Russian result. Better result could be achieved only by failed stall turn with tailslide and then true vertical dive. All this happens due to traditional Russian government strict regulations. Formally you have to submit fly plan for ANY flight, register everything etc, so it makes almost impossible to use civilian aircraft for fun and sport. So - everybody just drops all these stupid Stalins rules and do whatever he wants, until he is far enough from government (80 km from Moscow, deep in Kaluga region, deemed to be enough). Fly aeros on 200ft (not on 3000 where you can be spotted by radars etc), repair aircraft with sledge hammer in suspiciouse garage etc. If rules are dumb strict - they chucked out at all, together with all critical limitations.