Looking for a XYZ ARINC407 syncho explanation in simple terms

That must get interesting in a snap roll. Maybe that's why Frank reset things now and then.

The thing needing reset are the heading gyro ('gyrocompass') and maybe the attitude gyro ('artigicial horizon').

The turn indicator is set to respond to angular velocity around the airplane's vertical axis, and it does not need to be reset.

On a sunny day (Thu, 11 Feb 2021 09:48:44 -0800) it happened snipped-for-privacy@highlandsniptechnology.com wrote in :

Drones move too ,and fast sometimes

The 'reset' in my Hubsan drone is before you take off, you leave it a few seconds standing on the ground for horizontal gyro calibration. then rotate the thing horizontal for compass, then around vertical axis for compass (3 axis compass),

For a quad drone to move in some direction it has to slightly tilt forward in that direction: Not to scale:

\ 0 ---> \ So all you change is attitude, here now the air stream from the props is going to the left., and the thing to the right.

The chip has both an accelerometer AND a gyroscope. quote: " The MPU-60X0 is the world's first integrated 6-axis MotionTracking device that combines a 3-axis gyroscope, 3-axis accelerometer, and a Digital Motion ProcessorTM (DMP) all in a small 4x4x0.9mm package. With its dedicated I C sensor bus, it directly accepts inputs from an external 3-axis compass to provide a complete 9-axis MotionFusionTM output. ... "

So far my drone has had no problems with all this, and I did some wild things with it.

Have not tried flying upside down. would require the propellers to turn the other way... You can find out for yerself.

The Malibu has twin turbochargers. There is no vacuum available.

Something is wrong with your plane. It must be fxed before your next flight.

We are talking about the attitude indicator. There are no wires to the gyro. It is driven by vacuum. Venturis are subject to icing. The Malibu has a vacuum pump, one for each pilot seat.

AIUI, some drone IMU software used normal 3D coordinates and would suffer gimbal lock if they get to 90 degrees from horizontal. The more advanced ones use quaternions, and so can still work upside-down.

It's usual to have GPS, compass (magnetometer), gyro and accelerometers, and to fuse all those with a Kalman filter.

Check the code of px4 to know how it should be done.

CH

On a sunny day (Fri, 12 Feb 2021 09:53:39 +1100) it happened Clifford Heath wrote in :

Explain to me how you then reverse propeller direction, when you turn the thing 'upside down' it pushes the air upwards and digs a hole into the ground..

Of course for this Hubsan anything near 90 degrees is out of the question. Basically you need more downward directed air to keep the weight up there, and a relative much smaller amount to move forward (in horizontal direction relative to earth I mean). That is why I wrote 'not to scale'. In the youtube video you see this drone flying slowly horizontal and you cannot even see the tilt. The software (in this case reading simulated GPS data) limits the horizontal speed and sets the position in 3D from second to second. Load dropping:

Yes

The airplane was OK (Piper Turbo Arrow IV) and verified airworthy. It seems that you've never been on Finnish winter sky.

It seems that you did not read my previous posts. It is exactly what I wrote.

I'm not sure how that needs explaining. Obviously when the gravity vector is reversed the thrust must be also. The props aren't so efficient in the reverse direction either, and the control algorithm must take account of that.

I've seen video of a drone that can flip like this, but it's regarded as quite unusual. I don't think it's done by manual control - but by a pre-programmed flip manoeuvre commanded by a pushbutton.

CH

On a sunny day (Fri, 12 Feb 2021 22:37:45 +1100) it happened Clifford Heath wrote in :

Maybe just for show ? Does not make much sense to me.

Much better shows are the ones China does with drones in formation:

Is quite easy actually using that software I wrote to control the Hubsan but I only have one. EU now has, from the start of this year, new drone regulations and you have to get a license plus pass some tests, pay for it of course, thing needs an ID transmitter, just the usual fascist control trip by a bunch of old women brought into politics that are afraid of everything from cats to kitchen knives. I think I played enough and have a good attack system against their F35 whatever follies.

Sometimes it is better to be a pirate. Just imagine 100 toy drones appearing out of nowhere in front of an F35 taking off here locally. Hell it was already declared damaged when the fire brigade on the airport showered it with foam as welcome!

I am beginning to miss trump! We need wars to get rid of all the crap, especially all the US fake weapons but likely US will turn black, those multiply faster, due to their lower IQ but higher numbers they will grab power and claim they invented the wheel and everything after that, remove all references to how things really happened and black ages will start. I see similar crap happening here too, it is like a poison, whites start imitating it and there goes civilization (note the s*it babble music for example). CO2 crap, vaccines crap, green crap, sex equality crap, media censoring crap, total control of you and your data crap, printing money 24/7 to help everybody crap, lock-downs, no free speech (testing),

They had pitot heat on, but the tubes got filled up with crystals which overwhelmed the heating.

There are general aviation avionics which become completely useless if the pitot tube ices up. More recently they have been doing GPS backups for airdata, which is a good idea.

All these devices can be fooled - because they have to sense the gravity vector as a slow background process, so if you do "just the right kind of" flying for too long, you will fool it.

AIs can be vacuum driven or electric. The reason for the vacuum ones is that it avoids having two alternators (and two batteries, etc) for IFR certification. You can nowadays remove the vacuum system and go fully electric, with the cert requirement being met by a backup battery in the instrument; usually 1hr or so, which I don't regard as an acceptable solution :) But I have a backup alternator... OTOH I also still have the vacuum AI.

As I said, lots of work has gone into AHRS for navigation and nobody has got anywhere near. For attitude (pitch, roll, heading) yes, no problem, although you still need to feed a fluxgate (or some other mag field) sensor into the heading (Z axis yaw) gyro code - because long term accurate heading = viable solid state navigation :)

An airspeed indication of zero while you are flying clearly shows something is wrong with your plane. It cannot be certified airworthy.

It doesn't matter if you are in Finland or anywhere else. You cannot fly with an airspeed indicator that reads zero. [...]

I read your previous posts. Please state again what you wrote.

It seems that you have never met severe icing.

The indication returned as I descended out of the cloud and the pitot heat did its job.

It seems that Steve does not believe what severe icing does.

It was a surprise that all five pitots on AF447 went out of service.

The crew still had useable speed information from the navigation system, and the flight probably could have been salvaged if the crew had kept thrust and attitude constant after the upset. The gyros and engine instruments were fine.

In both cases when I have been in severe icing with an airplane not certified for it, I handled the situation with the navigation system information until out of the icing zone.

The turn indicator does not use the gravity reference. It just senses the rotation velocity around the airplane's vertival axis.

Tauno Voipio wrote

AF447 was, as usual, a combination of things

- all 3 pitot tubes icing up with crystals and removing airspeed data from both FMSs (this is not airframe icing btw which is anyway impossible at true airspeeds over ~350kt due to aerodynamic heating)

- pilots who didn't know anything about aircraft systems e.g. the pitch info on their PFDs being INS derived and thus reliable in an airspeed loss situation, and a plane can be flown with pitch+power => airspeed only

- oddball dodgy software e.g. stall warner disabled below 60kt, so when they got the plane into a deep stall, they had no further warning of it

- basically useless pilots; graduates from the elite national super-pilot "academy" with ~5000hrs of button-pushing experience

Severe icing (if meaning the actual classification term) is really dangerous; of the order of 1cm per minute or more. I've had it but had an escape route via descent. You don't want to get it above the Alps ;)

My Malibu was certified for flight into known icing. I have been in icing on several occasions that required activation of the boots, but nothing I would categorize as severe.

You could have prevented considerable waste of time by stating icing was the cause of your airspeed reading. It could also have been caused by numerous other issues which would have resulted in grounding the plane until they were fixed.

You stated

I asked for clairification, but you ignored my request.

Since you deliberately cause confusion by omitting relevant facts, and fail to specify the reason for your objections, I don't see a reason for wasting any more of my time with you.

Don't be a jerk. Of course I know what severe icing is. I was in the RCAF and have flown in icing conditions you would not believe.

Quote:

Yet, as the New York Times points out, "Investigators found that the loss of valid speed readings lasted for no more than a minute of the plane's terrifying four-minute descent." Even if the air-speed data had been lost entirely, the pilots could have saved the plane, BEA director Jean-Paul Troadec told reporters.

The big problem with Airbus is changing the flight characteristics when the plane gets into trouble.

Quote:

There are four reconfiguration modes for the Airbus fly-by-wire aircraft: alternate law 1, alternate law 2, direct law and mechanical law. The ground mode and flare modes for alternate law are identical to those modes for normal law.

With full up elevator, the plane stalled, but the stall warning was turned off when the airspeed was below a certain level. As soon as the pilot relaxed the control and the airspeed increased, the stall warning blared again until he returned to full up. Here is what happened:

Quote:

At 02:10:05 UTC, the autopilot disengaged, most likely due to hailstones blocking the pitot tubes, and the aircraft transitioned from "normal law" to "alternate law 2".[64]

The engines' auto-thrust systems disengaged three seconds later. As the pilot flying, first officer Bonin took over control of the aircraft, using the command language "I have the controls." Without the auto-pilot, the aircraft started to roll to the right due to turbulence, and Bonin reacted by deflecting his side-stick to the left. One consequence of the change to alternate law was an increase in the aircraft's sensitivity to roll, and the pilot's input over-corrected.

During the next 30 seconds, the aircraft rolled alternately left and right as Bonin adjusted to the altered handling characteristics of the aircraft. [65] At the same time he abruptly pulled back on his side-stick, raising the nose. This action has been described as unnecessary and excessive under the circumstances.[66]

The aircraft's stall warning briefly sounded twice due to the angle of attack tolerance being exceeded, and the aircraft's indicated airspeed dropped sharply from 274 knots (507 km/h; 315 mph) to 52 knots (96 km/h; 60 mph). The aircraft's angle of attack increased, and subsequently began to climb above its cruising altitude of 35,000 ft (FL350). During this ascent, the aircraft attained vertical speeds well in excess of the typical rate of climb for the Airbus A330, which usually ascend at rates no greater than

At 02:10:34 UTC, after displaying incorrectly for half a minute, the left- side instruments recorded a sharp rise in airspeed to 223 knots (413 km/h;

The icing event had lasted for just over a minute,[68][69][2]:198[70] yet first officer Bonin continued to make nose-up inputs. The trimmable horizontal stabilizer (THS) moved from three to 13 degrees nose-up in about one minute, and remained in the latter position until the end of the flight.

At 02:11:10 UTC, the aircraft had climbed to its maximum altitude of around

A second consequence of the reconfiguration into alternate law was that the stall protection no longer operated, whereas in normal law the aircraft's flight management computers would have acted to prevent such a high angle of attack.[71] The wings lost lift and the aircraft began to stall.[3]

Confused, first officer Bonin exclaimed "[Expletive] I don't have control of the airplane any more now", and two seconds later, "I don't have control of the airplane at all!"[28] First officer Robert responded to this by saying, "controls to the left", and took over control of the aircraft.[72] [31] Robert pushed his side-stick forward to lower the nose and recover from the stall; however, Bonin was still pulling his side-stick back. The inputs cancelled each other out and triggered an aural "dual input" warning.

At 02:11:40 UTC, captain Dubois re-entered the cockpit after being summoned by first officer Robert. Noticing the various alarms going off, he asked the two crew members, "er what are you (doing)?"[31] The angle of attack had then reached 40 degrees, and the aircraft had descended to 35,000 feet (11,000 m) with the engines running at almost 100% N1 (the rotational speed of the front intake fan, which delivers most of a turbofan engine's thrust). The stall warnings stopped, as all airspeed indications were now considered invalid by the aircraft's computer due to the high angle of attack.[73] The aircraft had its nose above the horizon but was descending steeply.

Roughly 20 seconds later, at 02:12 UTC, Bonin decreased the aircraft's pitch slightly. Airspeed indications became valid, and the stall warning sounded again; it then sounded intermittently for the remaining duration of the flight, stopping only when the pilots increased the aircraft's nose-up pitch. From there until the end of the flight, the angle of attack never dropped below 35 degrees. From the time the aircraft stalled until its impact into the ocean, the engines were primarily developing either 100 percent N1 or TOGA thrust, though they were briefly spooled down to about

everything".[31] Soon after this, Robert said to himself, "climb" four consecutive times. Bonin heard this and replied, "But I've been at maximum nose-up for a while!" When Captain Dubois heard this, he realized Bonin was causing the stall, and shouted, "No no no, don't climb! No No No!"[74][31]

When first officer Robert heard this, he told Bonin to give the control of the airplane to him.[2] In response to this, Bonin temporarily gave the controls to Robert.[31][74][2] Robert pushed his side stick forward to try to regain lift for the airplane to climb out of the stall. However, the aircraft was too low to recover from the stall. Shortly thereafter, the ground proximity warning system sounded an alarm, warning the crew about the aircraft's imminent crash with the ocean. In response, Bonin (without informing his colleagues) pulled his side stick all the way back again,[31] [2] and said, "[Expletive] We're going to crash! This can't be true. But what's happening?"[74][31][2][75][28] The last recording on the CVR was captain Dubois saying: "(ten) degrees pitch attitude."

So the design of the aircraft caused the crash.

I doubt you know what severe icing is.

Update: Captain Chesley Sullenberger, hero of "Miracle on the Hudson", shows how the copilot pulled the sidestick back and crashed the plane.

The sidesticks in the Airbus are not coupled together, so the pilot had no idea what the copilot was doing.

He also shows the same action would be difficult to conceal in a Boeing since the yokes are mechanically coupled together.