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Embraer loses instruments over Lisbon

Some details offered in the short Avweb report here
Not sure if true/confirmed.
- post-maintenance check flight (after one month in maintenance!) – no pax
- was guided by dispatched F-16s to an air force base for the landing

Sounds suspiciously like a maintenance foul-up.

LSZK, Switzerland

Silvaire wrote:

you steer right to initiate a turn to the left
Only above a certain (and high) speed for bikes (bicycles). For motorbikes said speed is very low because the front wheel is a lot heavier and hence gyroscopic effect.

ESMK, Sweden

No, true for bicycles at any speed. Also for scooters which have tiny wheels – or some snow or ice vehicles with no wheels at all.

Anyone who wants to experience how hard this is can simply try to shave using a non-reversing mirror (or a phone feont camera in non-reversing mode)

For increased realism, use a cut-throat razor.

A lot of flying and steering is happening subconsciosly, and is very difficult to override with consciois thought.

Using rudder and relying on yaw-induced roll sounds a lot more realistic

Biggin Hill

Re steering a two wheeler (stop reading now if this diversion bores you! ) There is a very low transition speed from steer left, go left to steer left, go right on any bicycle or motorcycle. The very low speed behavior is related to trail or castor, an aspect of the steering geometry, which moves the front wheel footprint slightly right when the handlebars are turned substantially left. At very low speeds (like slightly above the minimum at which you can balance) that causes the bike to fall ‘in’ and lean in the correct direction all on its own. At any higher speeds centrifugal cornering force comes into play and you have to steer the handlebars the ‘wrong’ way to drive front and rear footprints much further outside of the C.G. and achieve a bank angle in doing so. At some speed right in the middle you theoretically can’t steer at all, but that is such a narrow band of speed that the slightest acceleration puts you right again. The transition speed is so low that gyroscopic force in the wheel is not a significant factor.

All this is programmed unknowingly into your brain when you learn to ride a bicycle as a child, but with the right child you can accelerate their learning a lot by explaining ‘steer left, go right’

Last Edited by Silvaire at 14 Nov 00:47

Cobalt wrote:

Using rudder and relying on yaw-induced roll sounds a lot more realistic

I think that’s a very good point for any plane where the rudder induces roll effectively.

The issue would then be recognizing the aileron problem fast enough, for example on takeoff before you crash.

I do not know the validity of the source but sounds plausible if very scary:

quoted from a member on other aviation board, seems HiFly (Beja-based airline) Crew:
“It Was going back home after a C-check in Alverca.
Swapped aileron controls (so when a right input, the a/c would turn left and vice-versa). Only elevators, rudder and thrust available to control the aircraft. As far as I’ve heard from someone who talked to the crew when things were settled down on ground, no issues when the autopilot was connected, but as soon as they would disconnect it, the controls were lost everytime. One of the four tonneaux ended at around 4000ft on a 90º nose down attitude. Adding to these awkward conditions, the wheather here in Lisbon area have been awfull the whole day with pouring rain, heavy clouds and low ceiling, so they had no visual geographic references, plus they were unfamiliar with the terrain and there’s where the F-16s came in, to guide the E190 to a safer place. After “learning” to control the plane, all calmed down a little bit, but they needed an airport with better weather/visual conditions and Beja was the best(first option was sunny Algarve’s Faro), which is also in a sparsely populated (thus the lowest FR24 coverage, adding to the fact that the a/c doesn’t have ADS-B and only shows up in MLAT) area so in case of a crash, the possibility of having victims on the ground was much lower.
On the first landing attempt, the aircraft wasn’t well aligned to the runway so a go around was performed. On the second attempt they were a bit too high and went around again, before finally successfully landing on the third attempt. Of the 6 pob, two were taken to a local hospital with minor injuries and a third person, someone from the administration of Air Astana was reporting some heart issued ans was also taken to the hospital, which all three left by the beginning of the evening."

On the thrid attempt they landed on the runway but had a minor edge excursion knocking out some of the edge-lights in the process

Last Edited by Antonio at 14 Nov 06:25
Antonio
LESB, Spain

Silvaire wrote:

All this is programmed unknowingly into your brain when you learn to ride a bicycle as a child

Very interesting! The gyroscopically effect and human brain don’t alway correlate and the same is true on swapped aileron controls. Strangely the AP did it right but maybe it was connected the right way an only the yoke had the wrong input.

LSPG, LSZC, Switzerland
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