Originally Posted by Dogma
(Post 10234380)
. Try as I might, it seems a very bad idea at night, vs. going into the published hold and doing the procedure.
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Originally Posted by wiggy
(Post 10234662)
Laterally yes but I think the trap I see is where do you leave 6000 for 5000 feet if you are orbiting at 15 D? |
Originally Posted by Capn Bloggs
(Post 10234934)
I hope the fact you've mentioned/shown this doesn't embolden others to start their own terrain avoidance procedures...
That's different: the ATC is actively controlling you. It's his job to keep you clear of terrain. You request to do an orbit and you're under a RADAR service, ATC is monitoring you, you make a request and they either approve it or deny it. That aside, the chart shows the highest terrain so the numbers given seem sensible. There will not be a sector on that chart with a minimum altitude, not giving you the required terrain buffer (assuming no errors in the planning stage). So if ATC ever tells you 'Radar Control', who is responsible for terrain clearance? You are. That is why they provide you these charts to cross-reference their clearance (except in Milan because... Italy). How an earth could you ever avoid weather at night whilst making an approach (even to Amsterdam) if you had no choice but to stay above Minimum Sector Altitude (read Sector, NOT Safe)? Would you disagree that staying above the minimum radar altitudes in that chart would give you the required 1000ft terrain clearance? Bearing in mind a rate 1 orbit at 180kts should give you a turn diameter of about 2NM, if you had request one in any position under 'Positive Radar Control' (meaning you've been positively identified by ATC), they will (should) not allow you to maneuverer in a manner that would compromise safety by encroaching on the 1000ft terrain margin. Therefore, radar minimum sectors are defined with this in mind. Whenever you're inside a given sector of the MRC, any instruction/approved request should give you the legally required terrain avoidance - subject to your cross check of the relevant chart (in this case, your minimum radar chart). |
Originally Posted by giggitygiggity
(Post 10234951)
Is it!
You request to do an orbit and you're under a RADAR service, ATC is monitoring you, you make a request and they either approve it or deny it. .... .....Whenever you're inside a given sector of the MRC, any instruction/approved request should give you the legally required terrain avoidance - subject to your cross check of the relevant chart (in this case, your minimum radar chart). |
Originally Posted by A Squared
(Post 10234952)
giggity, not saying you're wrong, I agree with what you've posted, but even if this wasn't under radar control, you's still be performing the orbit within the published hold, on the same side of the localizer as the published hold, and at or above the published holding altitude. Radar control is just an additional layer of safety.
Originally Posted by A Squared
(Post 10234949)
Seems from the plate that "Established on the localizer and inside of 16.1 IGML/16.6 BDR" or "established on the localizer and on the glideslope" would both be safe, acceptable answers to your question. Do you have an instrument rating?
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Originally Posted by giggitygiggity
(Post 10234956)
Sorry, I wasn't replying to your post, but to Bloggs if that makes it clearer.
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Originally Posted by giggitygiggity
(Post 10234956)
I agree, with wiggy, that there is a little bit of a trap there as the plate is pretty messy to be quite frank. It could probably do with an expansion chart, though I'm not sure of the technical term - LIDO would call it "ILS 28 Initial". Note 1 also says that in accordance with the procedure you may descend down to 4800ft within 13.5 IMGL which I'm sure people will miss due to the wide 'zoom' shown.
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Giving it a bit more scrutiny, it may not be quite as bad as I thought. I guess they arrived on the okesa 1j arrival, so were already established on the final approach track, and were just high for the profile.
Quick fingers on the FMC would have put them round the race track (not the hold) and perfectly legitimately lost the height, but a 360 at tekbu would also seem to be within a protected area (SOPs permitting, which ours wouldn't). However, 6000' at tekbu is still slightly too high for the glide slope. If they did it at some point before tekbu then you're in uncharted territory at night with an 85 msa. I guess a 360 at the 16.6d BDR would be the limit, but you would need to be at 185kt. I would be wary of having the b'jaysus scared out of me by triggering the egpws by losing height directly over a big hill, so if it were me, I would either have loaded the racetrack, or press on to the BDR for the ILS V big race track. |
Originally Posted by Giggity
So if ATC ever tells you 'Radar Control', who is responsible for terrain clearance? You are.
Originally Posted by Giigity
How an earth could you ever avoid weather at night whilst making an approach (even to Amsterdam) if you had no choice but to stay above Minimum Sector Altitude (read Sector, NOT Safe)?
If you're doing you own thing though, as it appears here, John Wayneing an orbit below the 25nm MSA because you're high and in the area of the holding pattern is not on. You're either in the Hold or your not. Can't see the relevance of "500sqm"... |
Originally Posted by giggitygiggity
(Post 10234951)
Is it!
You request to do an orbit and you're under a RADAR service, ATC is monitoring you, you make a request and they either approve it or deny it. That aside, the chart shows the highest terrain so the numbers given seem sensible. There will not be a sector on that chart with a minimum altitude, not giving you the required terrain buffer (assuming no errors in the planning stage). So if ATC ever tells you 'Radar Control', who is responsible for terrain clearance? You are. That is why they provide you these charts to cross-reference their clearance (except in Milan because... Italy). How an earth could you ever avoid weather at night whilst making an approach (even to Amsterdam) if you had no choice but to stay above Minimum Sector Altitude (read Sector, NOT Safe)? Would you disagree that staying above the minimum radar altitudes in that chart would give you the required 1000ft terrain clearance? Bearing in mind a rate 1 orbit at 180kts should give you a turn diameter of about 2NM, if you had request one in any position under 'Positive Radar Control' (meaning you've been positively identified by ATC), they will (should) not allow you to maneuverer in a manner that would compromise safety by encroaching on the 1000ft terrain margin. Therefore, radar minimum sectors are defined with this in mind. Whenever you're inside a given sector of the MRC, any instruction/approved request should give you the legally required terrain avoidance - subject to your cross check of the relevant chart (in this case, your minimum radar chart). |
Originally Posted by Dogma
(Post 10235174)
An orbit at night is lacking in control, disorientating and bad idea
OK, how is 2 consecutive, 180 degree, rate 1 turns any more "lacking in control" and "disorienting" than 2, 180 degree, rate 1 turns connected with straight legs? Does the airplane get less stable somewhere around the 190th degree of turn? |
Originally Posted by Capn Bloggs
(Post 10235135)
If you're doing you own thing though, as it appears here, John Wayneing an orbit below the 25nm MSA because you're high and in the area of the holding pattern is not on. |
The IFR principles.
As I some times ask my Fo on my 31 second debrief before we go home : "Are we going to do that stunt if tomorrow is a linecheck!?"
" No Sir" "Good Lad , Class dismissed" Now for the hypothetical error made: Firstly, was the 360 done at 185kts, not likely. Secondly, was wind and drift taken into consideration, very unlikely. Third: Should I, if I loose the plot of my descend planning, invent something. when a safe shuttle in the hold is right in front of me? Now back for more coffee. Safe Regards Cpt B |
Ha ha bluey. I must use that one!
I think most manuals make for a provision for a 360, but ours is not below msa, not within 10 miles, and only in vmc. I've never used it and I don't like it because I find it disorientating, and it's easy to underestimate how much height is being lost and how fast, or to not keep it turning - and head off into God knows where or what. You'd also have to be ultra careful that you're not busting safe altitudes. |
Originally Posted by BluSdUp
(Post 10235212)
Now for the hypothetical error made: Firstly, was the 360 done at 185kts, not likely.
Originally Posted by BluSdUp
(Post 10235212)
Secondly, was wind and drift taken into consideration, very unlikely.
The terrain clearance area for racetracks and holds is designed with the assumption of some wind drift. The wind drift in a 360 turn is exactly the same as the wind drift in 2 180 turns of the same rate. |
Originally Posted by Capn Bloggs
(Post 10235135)
I knew somebody would rip into me for that. Pull ya head in, Giggity. I never said I pass all responsibility for terrain clearance to ATC when they are radar-vectoring me. We also don't have access to radar terrain charts. Given the gung-ho attitude of some here "she'll be right, no hills around here that I can see", that's probably a good idea.
Unless you're on radar vectors or a STAR, you ain't going below the MSA with me unless you're at the IAF. Weather in the way? Hold or go to your alternate! If you're doing you own thing though, as it appears here, John Wayneing an orbit below the 25nm MSA because you're high and in the area of the holding pattern is not on. You're either in the Hold or your not. Can't see the relevance of "500sqm"... Nope? Must be just something they have in the Jet2 OM then. |
Originally Posted by A Squared
(Post 10235183)
Still waiting for someone to explain how a 360 degree turn within the published racetrack, at or above the published racetrack altitude is more dangerous than flying the published racetrack.
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Originally Posted by VinRouge
(Post 10235242)
Can someone please direct me to the PANS OPS specification which permits me to swing in a 360 orbit on an instrument approach procedure
Originally Posted by VinRouge
(Post 10235242)
(get in everyone elses way) and just generally be a bit gash, in front of the rest of the flying community?
You folks are really starting to grasp at straws in your search for some justification to castigate this crew. Seriously, I'm expecting at any moment for one of you to claim that they turned you into a newt. |
Originally Posted by FlightDetent
(Post 10235259)
If you find him, please ask on my behalf, what's illegal about 4x 90 degree turn above MRVA authorized by ATC. Forgot to add, they'd be all in the same direction, and pretty consecutive too. :}
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Originally Posted by Time Traveller
(Post 10235223)
I think most manuals make for a provision for a 360, but ours is not below msa, not within 10 miles, and only in vmc. I've never used it and I don't like it because I find it disorientating, and it's easy to underestimate how much height is being lost and how fast, or to not keep it turning - and head off into God knows where or what. You'd also have to be ultra careful that you're not busting safe altitudes.
Fully agree with your description. The (pretty common) types I flew would as per FCTM go L/G down, mid-flaps and half spoilers at 180 knots to recover excessive altitude. Gives you between -1800, -2400 fpm in a straight line. If still too high (by 2000 ft above the platform, approaching the FAP - i.e. unrecoverable - let's imagine), the unfortunate decision to do a 360 would have you complete the full circle at 4000 below the target altitude. The obstacle clearance on the intermediate segment is 500 ft. Useless trick, that gets you nowhere but in trouble. The 360 is not the problem. The height loss through the turn and the position where executed could be, if ignorant of the underlying safe altitude limits. I said before my first picture: the chart provides enough information to execute a 360 in an organized and well-controlled manner. Exactly that. Adding now: execute both safely and legally, definitely at least the first of the two. Fair enough, on the other side of the ring: The terrain, high temps, wind aloft, and GS angle ALSO provide for a mine-field battleground, where a stupid 360 would turn into an Air Crash Investigators episode faster than one can say "Sink-Rate". Still bit perplexed why the need to hang Jet2 fellow crewmen or libel the whole company based on no evidence what they did if anything at all?! There will most likely be some, once we'd dig for it. Only then we could see which of the two scenarios fits the reality closer. And open the shooting range. |
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