It's An SRA Jim, But Not As We Knew It...
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It's An SRA Jim, But Not As We Knew It...
Has anyone been notified of changes to SRA advisory heights and glide angle? I was just told by a colleague at another unit (and I confirmed by checking in in the AIP) that instead of 3 degrees, it is now a "5.2% GRADIENT", with a descent profile of 320ft/nm (not 300) and the heights are given as:
6 1920
5 1600
4 1280
3 960
2 640
And therefore 1 mile = 320ft, 0 - 0ft. Hang on - what happened to the extra 50ft? I thought it based on aiming for the touchdown zone, not the end of the tarmac! For a perfectly flown 3 degree approach, deleting the 50ft would mean the aircraft touching down 1000ft short of the touchdown point. Ahh, but an SRA is only intended to get the pilots visual I hear you say. Fair enough - but all other non-precision approaches seem to have the 50ft included - why is an SRA different?
The eagle-eyed amongst you will note that this descent profile is slightly steeper than for a 3 degree approach (which equate roughly to about 4.8%). In fact, it starts above, and then descends below the previous profile. It would seem that (from the AIP) all non-precision approaches are now flown at a gradient %, not glide degree.
And this isn't only at my unit - I checked against two others in the AIP - exactly the same. No doubt this affects most, if not all, units. Not that I have a problem with change. What I have a problem with is that this particular change was dated 19 SEP 00 - everyone I have spoken to didn't have a clue this had happened (including LCEs) - so basically SRAs have been done incorrectly for over a year.
Did any units actually spot these changes? Who initiated them, and why? And why wasn't a big deal made of them - this would seem important!
And if this is news to you, go and check your unit AIP!
--------
The Lizard
Airlines start new cost reduction programme - readbacks cut by 30%
[Edited for poor use of the English language!]
[ 15 November 2001: Message edited by: TheLizard ]
6 1920
5 1600
4 1280
3 960
2 640
And therefore 1 mile = 320ft, 0 - 0ft. Hang on - what happened to the extra 50ft? I thought it based on aiming for the touchdown zone, not the end of the tarmac! For a perfectly flown 3 degree approach, deleting the 50ft would mean the aircraft touching down 1000ft short of the touchdown point. Ahh, but an SRA is only intended to get the pilots visual I hear you say. Fair enough - but all other non-precision approaches seem to have the 50ft included - why is an SRA different?
The eagle-eyed amongst you will note that this descent profile is slightly steeper than for a 3 degree approach (which equate roughly to about 4.8%). In fact, it starts above, and then descends below the previous profile. It would seem that (from the AIP) all non-precision approaches are now flown at a gradient %, not glide degree.
And this isn't only at my unit - I checked against two others in the AIP - exactly the same. No doubt this affects most, if not all, units. Not that I have a problem with change. What I have a problem with is that this particular change was dated 19 SEP 00 - everyone I have spoken to didn't have a clue this had happened (including LCEs) - so basically SRAs have been done incorrectly for over a year.
Did any units actually spot these changes? Who initiated them, and why? And why wasn't a big deal made of them - this would seem important!
And if this is news to you, go and check your unit AIP!
--------
The Lizard
Airlines start new cost reduction programme - readbacks cut by 30%
[Edited for poor use of the English language!]
[ 15 November 2001: Message edited by: TheLizard ]
For pilots using QNH (the majority of public transport flights, these days) are the threshold elevations added to the new figures? e.g. (elev. 127ft) :-
"Two miles, altitude should be 767 feet"
Terrific!
"Two miles, altitude should be 767 feet"
Terrific!
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OK, so if we have binned 3 deg glidepaths in favour of 5.20%, what percentage is a 3.5 deg glidepath?
My brain hurts............
[spelling]
[ 15 November 2001: Message edited by: Whipping Boy's SATCO ]
My brain hurts............
[spelling]
[ 15 November 2001: Message edited by: Whipping Boy's SATCO ]
Owch! WB's SATCO I agree completely. I had a headache before I'd finished reading the first paragraph. But then I'm only a young urchin, not yet worldly wise in the ways of the Force! 
Why doesn't everyone just get PAR 2000? Easy Peasy lemon squeezy! MASSIVE system redundancy should anythig actually break. "How many feet left or right of the centre-line would sir care to land today?" type technology. Lovely job!
Things are always worse than they seem!
Why doesn't everyone just get PAR 2000? Easy Peasy lemon squeezy! MASSIVE system redundancy should anythig actually break. "How many feet left or right of the centre-line would sir care to land today?" type technology. Lovely job!
Things are always worse than they seem!
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SATCO and WWW - my head still hurts from when I discussed this with Lizard-boy at work on Wednesday when we started to look into this.
Speke - It shouldn't get that complex as MATS Pt1 states to give advisory altitudes add the elevation to the advisory height and round up to the nearest 10 feet. So 770ft should sound better than 767!
Lizard - I've spoken to a mate at another unit who was just as surprised as we were to find out about the change. Another wondered if it is a JAR-OPS thing.
Just how many worms are crammed into this particular can?
Speke - It shouldn't get that complex as MATS Pt1 states to give advisory altitudes add the elevation to the advisory height and round up to the nearest 10 feet. So 770ft should sound better than 767!
Lizard - I've spoken to a mate at another unit who was just as surprised as we were to find out about the change. Another wondered if it is a JAR-OPS thing.
Just how many worms are crammed into this particular can?
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I was the one that started this problem.Having just done a validation at the Ice Station Z with the necessary SRA,I was left with a difficult decision on what to do.I chose the classic version SRA,but pointed out the the changes later to the "experts",only to be met by stunned mullet expressions from all...
The powers that be are saying that I've stirred up a real hornets nest here,but I was just pointing out what they are paid to do :Notice changes!!.I think that they cannot admit that they are negligent and it takes a mere Atco 3 re-tread to point out their shortcomings.71 % is enough!
The powers that be are saying that I've stirred up a real hornets nest here,but I was just pointing out what they are paid to do :Notice changes!!.I think that they cannot admit that they are negligent and it takes a mere Atco 3 re-tread to point out their shortcomings.71 % is enough!
Join Date: Oct 2001
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Get this then. A 3º GP is actually 318 ft per mile.
Soooooooo when everyone eventually gets used to 320' pm some pedant will decide that - wiv GPS an' everyfink - heights should be based on 318' pm!
Even pilots can calculate 300' pm for cross referencing a non-precision approach.
You know it makes sense.
Soooooooo when everyone eventually gets used to 320' pm some pedant will decide that - wiv GPS an' everyfink - heights should be based on 318' pm!
Even pilots can calculate 300' pm for cross referencing a non-precision approach.
You know it makes sense.
