Positive Rate/Positive Climb?
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From: dunnunda
Originally Posted by Hey Driver
Why is there such a rush to get the gear up? I regularly see guys calling for gear up before the ground/flight relays open.
On the matter of positive rate v positive climb, I don't believe the intent or reference instruments are different. Just a different term.
Ive had one bloke tell me how the Rad Alt is his reference for positive rate.
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From: dunnunda
And the radalt may just show a positive increase during rotation (because the antenna are forward of the wing leading edge) with the mains still on the ground.
And, I've had enough people call "positive rate" with the altimeter indicating an altitude less than that at the start of the takeoff run, to know they're not really seeing any true indication that we're climbing.
And, I've had enough people call "positive rate" with the altimeter indicating an altitude less than that at the start of the takeoff run, to know they're not really seeing any true indication that we're climbing.
Last edited by Capt Claret; 17th August 2012 at 01:01.
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From: Home soon
And, I've had enough people call "positive rate" with the altimeter indicating an altitude less than that at the start of the takeoff run, to know they're not really seeing any true indication that we're climbing.
You wanna think about this one again?
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From: Glorious West Sussex
Read the airbus books again.....
-POSITIVE CLIMB..................ANNOUNCE
Announce positive climb, when the vertical speed indication is positive and the radio altitude has increased.
Any questions?
-POSITIVE CLIMB..................ANNOUNCE
Announce positive climb, when the vertical speed indication is positive and the radio altitude has increased.
Any questions?
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From: dunnunda
Originally Posted by Boeing 717 FCOM - Vol II - Operating
after rotation PNF: Verify and call “positive rate”.
I still reckon if the altimeter shows a level lower than that at the start of the takeoff roll, one should not call "positive rate" yet.
Last edited by Capt Claret; 17th August 2012 at 07:49.
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From: Germany
And, I've had enough people call "positive rate" with the altimeter indicating an altitude less than that at the start of the takeoff run, to know they're not really seeing any true indication that we're climbing.
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From: dunnunda
Originally Posted by aerobat77
when the cows on the field are getting smaller and smaller its a sure way to determine you are climbing i would say
But when the call "gear up" or "positive rate" is made as the mains leave the ground, one can't always be sure that the cows will remain in sight.
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From: Bournemouth
I don't yet fly aircraft with retractable gear so please forgive the question, but what are the criteria which need to be met for the 'gear up' call? Is it just a case of "positive rate" from the pilot monitoring results in an automatic "gear up" call from the pilot flying, or is there more to it than that? Thanks, Rich
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From: dunnunda
I don't yet fly aircraft with retractable gear so please forgive the question, but what are the criteria which need to be met for the 'gear up' call? Is it just a case of "positive rate" from the pilot monitoring results in an automatic "gear up" call from the pilot flying, or is there more to it than that? Thanks, Rich
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From: dunnunda
G'day TP,
Until this conversation I'd not considered Rad Alt as a source, probably because for 20 odd years I've used VSI plus Altimeter, so I wouldn't be brave enough to suggest Airbus (no bus time personally) has it wrong.
However, much like an engine failure where two instruments should be used to identify the failed engine, I believe it unwise to rely on only one source for positive rate. I guess my main bone of contention, is being asked to retract the gear as the mains leave the ground with no thought of what might happen should the aircraft encounter a downdraught or for whatever reason not really be climbing away. Sort of like the occasional incidents of folks selecting gear up on the ground and relying on the squat switch to keep the gear from retracting (admittedly this is usually associated with light aircraft).
In the 717 FCOM, there's no explanation as to why Boeing recommends the PNF observe positive rate, call it, then the PF confirms same before calling for gear up. But were I a betting man, I'd reckon that at least one reason is to slow the process of gear retraction just a little, to ensure the aircraft is properly gaining altitude, and doesn't settle back onto the runway on its belly.
Until this conversation I'd not considered Rad Alt as a source, probably because for 20 odd years I've used VSI plus Altimeter, so I wouldn't be brave enough to suggest Airbus (no bus time personally) has it wrong.
However, much like an engine failure where two instruments should be used to identify the failed engine, I believe it unwise to rely on only one source for positive rate. I guess my main bone of contention, is being asked to retract the gear as the mains leave the ground with no thought of what might happen should the aircraft encounter a downdraught or for whatever reason not really be climbing away. Sort of like the occasional incidents of folks selecting gear up on the ground and relying on the squat switch to keep the gear from retracting (admittedly this is usually associated with light aircraft).
In the 717 FCOM, there's no explanation as to why Boeing recommends the PNF observe positive rate, call it, then the PF confirms same before calling for gear up. But were I a betting man, I'd reckon that at least one reason is to slow the process of gear retraction just a little, to ensure the aircraft is properly gaining altitude, and doesn't settle back onto the runway on its belly.
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From: North of CDG
"Positive climb" always makes me smile. A climb is always positive; otherwise, it would be a descent... unless you call that a "negative climb"!
So in my case, "positive rate" it is. And yes, that means increasing VSI, ALT, and IAS. Plus of course the houses getting smaller (if in VMC)...
But at the end of the day it's just one manufacturer trying to be clever...
Cheers
So in my case, "positive rate" it is. And yes, that means increasing VSI, ALT, and IAS. Plus of course the houses getting smaller (if in VMC)...
But at the end of the day it's just one manufacturer trying to be clever...
Cheers
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From: earth
For me, positive rate makes me think of VSI, positive climb is the A/C flying away from the ground, checking all available sources, VSI,ALT, RA, houses getting smaller etc, some VSI, not dampenned by the IRS, can indicate a climb during the change of attitude at rotation. Calling positive climb seems to be indicating that I've checked the A/C is climbing for real!
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From: Milano
Any actual thoughts on why RA is not a suitable reference for the call? airbus might be wrong...
Ciao,
Dg800
