cross hairs vs v-bar
Thread Starter
cross hairs vs v-bar
Had the good fortune of taking an Airbus for a drive around YMML the other night....well...a certain company simulator. The obvious thing to springs to my mind compared to the last time I had the chance of poling such an advanced beast. Why have we gone back to chasing cross hairs?
This may well be an old chestnut of an argument, but. Why have we gone away from an intuitive, rate based command bar?
All the information required was all there. However, you had to look at the trends in each individual tape to try and ascertain if your input was meeting performance. Granted, this is the observation of a lowly non instrument rated PPL, BUT, poling a vbar equipped B200 compared to the bus....the B200 was by far easier to steer around an instrument approach than following the cross hairs...information was the same but not intuitive.
Other than that, not a bad truck to pole around
....once you stop yourself from trying to fly the stick rather than input and check...how many times instructor said and it is so hard to stop doing it...PIO city here we come
This may well be an old chestnut of an argument, but. Why have we gone away from an intuitive, rate based command bar?
All the information required was all there. However, you had to look at the trends in each individual tape to try and ascertain if your input was meeting performance. Granted, this is the observation of a lowly non instrument rated PPL, BUT, poling a vbar equipped B200 compared to the bus....the B200 was by far easier to steer around an instrument approach than following the cross hairs...information was the same but not intuitive.
Other than that, not a bad truck to pole around
....once you stop yourself from trying to fly the stick rather than input and check...how many times instructor said and it is so hard to stop doing it...PIO city here we come
Last edited by OZBUSDRIVER; 23rd Apr 2013 at 22:07.
I never did like the command bars. They worked, but seemed to draw my scan into nailing the accuracy of the glideslope/LLZ at expense of other important stuff like altimetry.
I prefer old-school (hand flown on the AI, no flight director), the only assist being a track bug so you're not guessing drift kill heading.
However I never really did give it a fighting chance, I know lots of people who swear by the flight director bars.
I prefer old-school (hand flown on the AI, no flight director), the only assist being a track bug so you're not guessing drift kill heading.
However I never really did give it a fighting chance, I know lots of people who swear by the flight director bars.
Because the rocket-scientists of Toulouse said so.
It's a company preference that is decided by the flick of a switch on the PFD. Boeings also have the cross hairs for FD commands.
It's a company preference that is decided by the flick of a switch on the PFD. Boeings also have the cross hairs for FD commands.
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I've flown both, and I can't stand the crosshairs...but I did like the V bars (AKA: howard johnson roof or bat wings).
I remember hating the crosshairs so much about 24 years ago in the BAE146, that I hit PITCH SYNCH constantly and just flew the damng thing...stupid sim instructor said...BOY YOU NAILED THOSE CROSSHAIRS.
sheesh
I remember hating the crosshairs so much about 24 years ago in the BAE146, that I hit PITCH SYNCH constantly and just flew the damng thing...stupid sim instructor said...BOY YOU NAILED THOSE CROSSHAIRS.
sheesh
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Why have we gone away from an intuitive, rate based command bar?
All the information required was all there. However, you had to look at the trends in each individual tape to try and ascertain if your input was meeting performance. Granted, this is the observation of a lowly non instrument rated PPL...
All the information required was all there. However, you had to look at the trends in each individual tape to try and ascertain if your input was meeting performance. Granted, this is the observation of a lowly non instrument rated PPL...
The F/D cross hairs on 'le bus' are rate based. They provide directions to 'lead' turns or altitude changes to end up at the selected parameter using the predefined capture criteria as applied to the instantaneous dynamic flight path.
All you had to do was 'fly the bars'.
Barring any simulator fidelity issues, the difficulty you experienced in using the Flight Director "cross hairs" was a result of sub optimal operator input.
Tradesman and tools!
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Used the cross hairs on classic 747s 20 years ago in the box and da plane and found 'em to be superior to V bars.
The world has changed and now it is all about V bars.
Guess it is okay as long as the pay check comes on time every month.
(Guess I have lost interest
)
The world has changed and now it is all about V bars.
Guess it is okay as long as the pay check comes on time every month.
(Guess I have lost interest
)
If you nail the crosshairs, everything else looks after itself.
As a direct result of this, airline Pilots have lost their primary scan rate, focussing mainly on the crosshairs, with secondary scans to the primary flight instruments.
There was a university study done some time ago recording Pilots eye movements on glass vs analogue.
I love the crosshairs, I also love the bird. Once I worked out what the bird was telling me I have loved it ever since.
You can't beat polling a bus by hand around the circuit. For such an automated aircraft, it's a pleasure to handfly the computers without the FDs and AP on!
As a direct result of this, airline Pilots have lost their primary scan rate, focussing mainly on the crosshairs, with secondary scans to the primary flight instruments.
There was a university study done some time ago recording Pilots eye movements on glass vs analogue.
I love the crosshairs, I also love the bird. Once I worked out what the bird was telling me I have loved it ever since.
You can't beat polling a bus by hand around the circuit. For such an automated aircraft, it's a pleasure to handfly the computers without the FDs and AP on
!
Thread Starter
Agree Trent, everything was there by maintaining alignment. And, I very much agree on sub- optimal input from the biological interface. It was apparent comparing flying to the cross hair as opposed to matching your attitude with that of the command bar...intuitive! Training and experience take care of any system interface...this was a first impression.
Regardless, the systems would take me a lifetime to digest but the simulator certainly showed how simple it can be. Just throw in adverse wx, multiple atc changes and radio calls, traffic and the like and see how I sink real fast! It did give me an insight into managing the system that is Airbus....I just like v-bars
Enjoyed every last second of it!
Regardless, the systems would take me a lifetime to digest but the simulator certainly showed how simple it can be. Just throw in adverse wx, multiple atc changes and radio calls, traffic and the like and see how I sink real fast! It did give me an insight into managing the system that is Airbus....I just like v-bars
Enjoyed every last second of it!
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What about the Flight Path Director?
Personally single cue is probably the easiest but I find cross pointer makes for a more accurate approach. The FPD is by far the most accurate and as easy to follow as the S-Cue with the roll command. I found it does take a bit to get use to with the pitch holding steady while the command is moving around with the indicator but once you expand your scan beyond it becomes very intuitive.
FPD is also the way of the future and the most suitable command for synthetic vision or Hud, so might as well get used to it.
Personally single cue is probably the easiest but I find cross pointer makes for a more accurate approach. The FPD is by far the most accurate and as easy to follow as the S-Cue with the roll command. I found it does take a bit to get use to with the pitch holding steady while the command is moving around with the indicator but once you expand your scan beyond it becomes very intuitive.
FPD is also the way of the future and the most suitable command for synthetic vision or Hud, so might as well get used to it.
Last edited by avconnection; 24th Apr 2013 at 15:25.
I believe 'Trent' summed it up well & at the end of the day whatever you feel comfy with is okay. I've driven both types & I do find the cross-hairs less intrusive in the picture. I luv the no-trim machine, just set & almost 4get
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They can stick those stupid V bars where the sun doesn't shine. Bloody orrible things which I found more of a hinderance than a help. I found the crossbars to be far more accurate; no estimating exactly where to put the aircraft symbol on the V, just get the bars crossed in the box. It's funny, but I've found the V bar advocates all hark back to the 'old days', the same sort that shun any automation or helpful gizmos. Why make life more difficult than it has to be
just get the bars crossed in the box
)That concentration is therefore on one single instrument and normal basic instrument scan never gets a chance. Result being the majority of airline pilots steeped in flight directors soon lose their confidence to be able to fly without the aid of a flight director. Shows out in heaps in the simulator. Thread drift - sorry
Once used to the inputs required on either system, the fact is they present identical information. (Trent nailed it)
That said, with approximately equal time on both, I do believe the single cue system is more intuitive and requires less scanning, leaving more time to scan the other instruments.
The ininital problem I had with the roll command on the crosshairs was treating it like a localiser signal rather than a pure roll command. Transitioning from a single cue, it took a while to feel nautral.
That said, with approximately equal time on both, I do believe the single cue system is more intuitive and requires less scanning, leaving more time to scan the other instruments.
The ininital problem I had with the roll command on the crosshairs was treating it like a localiser signal rather than a pure roll command. Transitioning from a single cue, it took a while to feel nautral.
Originally Posted by Lookleft
Because the rocket-scientists of Toulouse said so.
It's a company preference that is decided by the flick of a switch on the PFD.
It's a company preference that is decided by the flick of a switch on the PFD.
Have flown Hairbrushes with only cross-hairs but flown two different glass Boeings with both V bars and cross-hairs so it definitely is an option. We were able to have the small airline I worked for change from V bars to crosshairs for several reasons. The question is exactly where does one put the aircraft symble on the V bar? Just tucked under it by one micrometer or overlapping it. It can make a difference. With cross-hairs there is not such a dilema-centered is correct. The biggest reason however is that there is no split cue ability. If roll command is lost (for any of a number of reasons) the roll bar is removed and pitch can still be flown on the on pitch bar. Equally if pitch command is lost the roll bar is left for you. On a V bar if either is lost the V bar goes on holiday. Years ago almost all the Chinese airlines had V bars in contrast to the rest of the world. Not so sure now. Jetstar has cross-hairs on their 320 so presume it would be the same on the 330s.
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Centaurus
How 's it any different putting the crosshairs over the box to fornicating with the v-bars? Same degree of effort from my experience and I'm presently flying a/c with both. Also wasn't that the intention, to reduce the number of flt instruments that needed to be scanned? I'm plain lazy these days, but in the past around every 4th approach was fd/ap/at off and that kept the scan rate to an acceptable level.
GG, OMFG, WHAT polling the bus WITHOUT the FD and AP!! You'll surely die!
Have to say a large part of the fun has somewhat evaporated from the job these days.
GG, OMFG, WHAT polling the bus WITHOUT the FD and AP!! You'll surely die!
Have to say a large part of the fun has somewhat evaporated from the job these days.
Even with v bars I would assume the majority of pilots couldnt fly power and attitude if they lost their flt director. It's unfortunately a side effect of the modern glass cockpit. It's not something thats taught anymore.
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I guess preference is the main driver. I was brought up to look through the FD and fly the raw data regardless of what the flight director might have been doing.
On the earlier FDs, especially if things were a bit dynamic, it was always much easier to fly the raw data rather than trying to second guess the FD .. or maybe that was just my incompetence ?
Having said that, I never liked the bird on the 727 but found the needles on the 737 very easy to interpret.
On the earlier FDs, especially if things were a bit dynamic, it was always much easier to fly the raw data rather than trying to second guess the FD .. or maybe that was just my incompetence ?
Having said that, I never liked the bird on the 727 but found the needles on the 737 very easy to interpret.
