Airbus aircraft sidestick target on PFD
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But what says your manual FCOM DSC-27-20-30 ?
Still last year we had a mix in our fleet, but lately all aircrafts have been standardized and the white cross has already disappeared for the rotation process itself.
Still last year we had a mix in our fleet, but lately all aircrafts have been standardized and the white cross has already disappeared for the rotation process itself.
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Originally Posted by RWU
FCOM tends to be irrelevant as depending on age the aircraft tend to be different.
Quote from CONF_iture:
"But Roll Normal is not fully active before 2 sec after attitude is over 8 deg. Until that time the roll is still under Ground Mode when aileron deflection is proportional to Sidestick deflection. As you state, pilot's action is necessary to prevent the upwind wing to rise during rotation."
Bien-sure, although I certainly could not confirm that your precise figures (2 seconds after Pitch +8) are the same for the A320, and my FCOM is way out of date. I think the most likely time for the wing to rise is when the wing starts to "fly", but the main wheels are still providing directional stability. At that stage, the a/c is still, in effect, side-slipping in the crosswind, and roll control is still stick-to-aileron/spoiler.
My own practice was to retain the original aileron after 100 knots, and be prepared to increase it (if necessary) during rotation until Roll Normal law kicked in. Better to have a brief extension of the spoilers during rotation, than for the a/c to roll downwind.
"But Roll Normal is not fully active before 2 sec after attitude is over 8 deg. Until that time the roll is still under Ground Mode when aileron deflection is proportional to Sidestick deflection. As you state, pilot's action is necessary to prevent the upwind wing to rise during rotation."
Bien-sure, although I certainly could not confirm that your precise figures (2 seconds after Pitch +8) are the same for the A320, and my FCOM is way out of date. I think the most likely time for the wing to rise is when the wing starts to "fly", but the main wheels are still providing directional stability. At that stage, the a/c is still, in effect, side-slipping in the crosswind, and roll control is still stick-to-aileron/spoiler.
My own practice was to retain the original aileron after 100 knots, and be prepared to increase it (if necessary) during rotation until Roll Normal law kicked in. Better to have a brief extension of the spoilers during rotation, than for the a/c to roll downwind.
For all 200 odd of our aircraft:
There have certain technical aspects in the past not reflected by FCOM.
i.e. that an aircraft in alternate law will not always go into Direct Law when the gear is extended!
On the ground, after the first engine start, sidestick position indications appear white on both PFDs. The indications disappear when the aircraft goes from the ground into flight.
i.e. that an aircraft in alternate law will not always go into Direct Law when the gear is extended!
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Originally Posted by Chris Scott
Bien-sure, although I certainly could not confirm that your precise figures (2 seconds after Pitch +8) are the same for the A320
Originally Posted by RWU
see Air2000 Bristol tail strike
Synopsis of the Air2000 incident.
had initiated rotation at the correct speed but he had rapidly applied appreciably more rearwards side-stick than any other pilot within a sample of seven other flights. He had also applied a large lateral side-stick deflection before and during rotation which was sufficient to deploy the roll spoilers on the left wing. Spoiler deployment during rotation has two undesirable effects: it decreases wing lift and it increases the nose-up pitch rate. The combined effect of the aft and lateral side-stick inputs was a sustained pitch rotation rate of more than twice the recommended rate of 3°sec.
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WHITE CROSS ON PFD
This symbol is a signature of Ground law being in force and disappears when ground law is no longer valid. It is a pointer of rate of side stick movement by the handling pilot. It is a cursor that is a visual indication of side stick movement and allows monitoring of the side stick deflection against max deflection limits as demarcated by the white partial box on the face of the PFD during Ground law mode after engine start.Is used as ref during flight control check deflections.
Last edited by Vc10Tail; 4th Feb 2013 at 08:16.
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Originally Posted by RWU
Synopsis of the Air2000 incident.
Interesting to note that the PF was not a low time guy but a captain with TT5000H and half of it on type. Because we may all need supervision, whatever our experience, depending on the conditions and the fatigue state. The Sidestick concept by Airbus suppresses a valuable tool for natural and easy supervision.
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Originally Posted by DOZY
If the PF was a Captain with 5000+ hours, what reason would the PNF have had to follow through on the PFC during the roll and correct where necessary?
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white cross on PFD
QUOTE FCOM Rev Dec 2012
Ident.: DSC-27-20-30-00001094.0001001
Applicable to: ALL
On the ground, after the first engine start, sidestick position indications appear white on both PFDs.
The indications disappear when the aircraft goes from the ground into flight.
Ident.: DSC-27-20-30-00001094.0001001
Applicable to: ALL
On the ground, after the first engine start, sidestick position indications appear white on both PFDs.
The indications disappear when the aircraft goes from the ground into flight.
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SS confirmation
Flew a 330 -300 today with very aft loading ... As per my previous post about NW extension inhibiting it, this is exactly what occurred as we bounced down the runway and the nose wheel bounced a liitle up and down,.. The stick and boxed corners of its travel limits came in and out a few times... It also dissappeared again once a rotate had been initiated , last seen at about 8 deg up stick as the rotate progressed. Wja
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From more research I got this answer!
The main goal of the sidestick position indications is to keep the PNF aware of the inputs made by the PF when there is no aircraft response upon these inputs, which is the case on ground only. This indication is for PNF awareness in general.
For example, during flight control checks, the crew has to verify that the flight control surfaces go to the full deflection and in the correct direction (PRO-NOR-SOP-10-A). The full deflection is to be checked on the ECAM F/CTL Page. To check that the deflection is in the correct direction, the PF will compare the sense of his/her action on the side stick with the callout made by the PNF. The PNF primary task is to check the surfaces deflection on the ECAM F/CTL page and to announce its direction. However, the PNF may additionally compare the direction of the displacement of the deflection of the surfaces on the F/CTL page with the direction of the side stick symbol on the PFD.
The sidestick position on the PFD may also be used by the PNF (not the PF) during initial takeoff roll to check that the PF is making an appropriate control input. Please note that this indication must not be used by the PF during takeoff rotation.
We hope this satisfactorily responds to your request. We encourage you to provide us with your feedback using the questionnaire below, and we remain available for any additional information and assistance.
The main goal of the sidestick position indications is to keep the PNF aware of the inputs made by the PF when there is no aircraft response upon these inputs, which is the case on ground only. This indication is for PNF awareness in general.
For example, during flight control checks, the crew has to verify that the flight control surfaces go to the full deflection and in the correct direction (PRO-NOR-SOP-10-A). The full deflection is to be checked on the ECAM F/CTL Page. To check that the deflection is in the correct direction, the PF will compare the sense of his/her action on the side stick with the callout made by the PNF. The PNF primary task is to check the surfaces deflection on the ECAM F/CTL page and to announce its direction. However, the PNF may additionally compare the direction of the displacement of the deflection of the surfaces on the F/CTL page with the direction of the side stick symbol on the PFD.
The sidestick position on the PFD may also be used by the PNF (not the PF) during initial takeoff roll to check that the PF is making an appropriate control input. Please note that this indication must not be used by the PF during takeoff rotation.
We hope this satisfactorily responds to your request. We encourage you to provide us with your feedback using the questionnaire below, and we remain available for any additional information and assistance.
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You have obviously also missed a notorious serious incident report.
Cross is certainly not to be used by the PF for rotation.
Cross is certainly not to be used by the PF for rotation.
To cut a long story short, if I have the same story - the resultant factor was that the PF was not using the cross as a stick indication, which I am sticking to, but, that he used it as an aircraft pitch ATT indication, if I am right.
Also, rather unnervingly - an instructor once told me in a sim session, that if I place the cross on the pitch angle I want, on the . . artificial horizon (pitch bar) then the aircraft would pitch to that . . pitch attitude or alpha.
For example, he meant, if I placed the cross on the 10 degree pitch bar then I would pitch up to 10 degrees nose up.
I have a tiny inkling that this is complete and utter
.But please correct me if I am wrong.
Sounds very dodgy - by which I mean anyone using the white cross as any sort of flight indicator/director is barking up the wrong and very dodgy tree.
The White cross is NOT a flight director, NOR is it any sort of aircraft attitude indicator. The white cross shows the sidestick position ONLY.
I guess this potential confusion, (although frankly it beggars belief), might be why Airbuses now remove the white cross very soon after rotation.
The White cross is NOT a flight director, NOR is it any sort of aircraft attitude indicator. The white cross shows the sidestick position ONLY.
I guess this potential confusion, (although frankly it beggars belief), might be why Airbuses now remove the white cross very soon after rotation.
Quotes from Uplinker:
(1)
"The White cross is NOT a flight director, NOR is it any sort of aircraft attitude indicator. The white cross shows the sidestick position ONLY."
Indeed. Describing the white cross as a "sidestick target", as in the title of this thread, is misleading. I'm not sure where the OP got the expression from, actually. It's 11 years since I flew the a/c, but my original A320 FCOM, dated Feb 1988, describes them (one per PFD) as follows:
"On ground, side stick position indications appear white on CPT and FO PFD."
(2)
"I guess this potential confusion, (although frankly it beggars belief), might be why Airbuses now remove the white cross very soon after rotation."
Yes, but you could omit the "now". As one of the first line pilots to fly the A320 (March 1988), I can assure you it was ever thus.
(1)
"The White cross is NOT a flight director, NOR is it any sort of aircraft attitude indicator. The white cross shows the sidestick position ONLY."
Indeed. Describing the white cross as a "sidestick target", as in the title of this thread, is misleading. I'm not sure where the OP got the expression from, actually. It's 11 years since I flew the a/c, but my original A320 FCOM, dated Feb 1988, describes them (one per PFD) as follows:
"On ground, side stick position indications appear white on CPT and FO PFD."
(2)
"I guess this potential confusion, (although frankly it beggars belief), might be why Airbuses now remove the white cross very soon after rotation."
Yes, but you could omit the "now". As one of the first line pilots to fly the A320 (March 1988), I can assure you it was ever thus.
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Yes, but you could omit the "now". As one of the first line pilots to fly the A320 (March 1988), I can assure you it was ever thus.
IOW the white cross used to be displayed for the full rotation, but not anymore.
As mentioned earlier by woodja51, depending on the CG, THS setting, RWY surface, the white cross can already disappear or at least blink during the take off roll.
Quote from CONF_iture:
"There is a difference here as the white cross used to disappear when main gear oleos were fully extended but now, the white cross disappears as soon as the nose gear oleo is fully extended, at least on the 330s I know."
Yes, the logic may have changed very slightly, and it seems to be subtley different on the different types - I don't think we've precisely nailed that one. I was simply responding to Uplinker's less specific point that "Airbuses NOW remove [it] very soon after rotation" [my emphases]. I don't think we would argue with that as a pilots' practical description?
But I wanted to emphasise that, at any rate since A320 type certification in February 1988, the white cross has never been visible for a significant period after rotation.
Quote from OK465:
"Just a technical point, but the cross represents SS 'commands' in effect, not necessarily SS position."
Yes, as in the famous incident where an a/c came off maintenance with the transducers on one sidestick cross-wired (connectors not Murphy-proof). My quote was from a FCOM that predated that incident by many years!
Do we all agree that to call the white cross a "TARGET" is misleading? What do the current FCOMs call it?
"There is a difference here as the white cross used to disappear when main gear oleos were fully extended but now, the white cross disappears as soon as the nose gear oleo is fully extended, at least on the 330s I know."
Yes, the logic may have changed very slightly, and it seems to be subtley different on the different types - I don't think we've precisely nailed that one. I was simply responding to Uplinker's less specific point that "Airbuses NOW remove [it] very soon after rotation" [my emphases]. I don't think we would argue with that as a pilots' practical description?
But I wanted to emphasise that, at any rate since A320 type certification in February 1988, the white cross has never been visible for a significant period after rotation.
Quote from OK465:
"Just a technical point, but the cross represents SS 'commands' in effect, not necessarily SS position."
Yes, as in the famous incident where an a/c came off maintenance with the transducers on one sidestick cross-wired (connectors not Murphy-proof). My quote was from a FCOM that predated that incident by many years!
Do we all agree that to call the white cross a "TARGET" is misleading? What do the current FCOMs call it?
Last edited by Jetdriver; 20th Mar 2013 at 03:03.
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Nowhere in the FCOMs is the white cross on the PFD referredto as the ‘Maltese‘ cross, although it does resemble the George Cross on the Maltese flag.
The Maltese cross isan eight pointed cross similar to the FAF symbol on Jeppesen charts.
The Maltese cross isan eight pointed cross similar to the FAF symbol on Jeppesen charts.