Very confused with Engine Out SID
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The calculations are much too complicated.
We limit the landing weight based on the Missed Approach Gradient for certain airports.
Mutt
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A few thoughts ..
(a) Your company will have produced ...
Most do, some don't .. it is good practice for the commander to know which sort of company it is for which he/she flies.
(b) If you are able (performance-wise) to follow the normal SID and the required climb profile it is advisable to fly that since ATC does not know your EOSID
Fair comment - but the ops eng folk need to have looked at this topic in detail to make sure that tracking is feasible from the approach and that net profiles, especially third segment acceleration and turn radius is OK. That is to say, not appropriate for the commander to figure out on the fly.
(c) To use a certain procedure you have to meet the required climb gradients
Do keep in mind that gradients are only part of the problem. Configuration changes, gross/net decrements, and turn gradient delta/radius complicate things.
(d) .. the commander may always decide differently ..
But do make sure you have a good story for the Enquiry. Be very wary of continuing visually in tiger country areas - the gradients are very shallow and not amenable to winging it as we go.
(e) You may get your engine failure at 3000' with the engine out procedure behind you... but will you make it above the 12000' peak ahead of you?
A good ops engineer will have looked at ALL the possibilities until you are above all relevant terrain. Unfortunately, not all ops engineers are operationally savvy and, if this is the case, the exercise should involve a joint ops eng/flight standards liaison.
(f) The point is that you only have to meet the gradient ..
Not adequate. Please do keep configuration changes and turn deltas/radius in mind.
(g) I would also commend looking at a topo chart if you'd be unable to meet the gradient
Topos give useful background - particularly in respect of the big picture stuff. They are not too bad at telling you that there is a BIG hill here or there ... however, they are NOT terribly accurate or useful when it comes to figuring critical net clearances.
Further the sorts of errors which creep into the topo world are legion.
In the real world of ops engineering we use the topo to figure out where the difficult bits might be and then, if it is really critical, a couple of fine chaps/chapesses draw the short straw and have a fun day out in the bush with a theodolite and associated kit.
(h) When visual a Mk I eyeball is also a useful tool.
So long as it is limited to staying away from big hills in the same way that we eyeball staying away from thunderstorms. Mk I eyeball is pretty useless for scraping over ridges and such like OEI.
(i) Are you aware that your gradient diminishes in turns
Something similar to operating at higher weights (load factor effect). The specific sums might vary a bit but, typically, expect something in the region of 0.6 - 1.0 percent decrement, give or take.
(j) It boils down to never go anywhere in an a/c that your brain hasn't been first.
That's not a bad philosophy ..
(k) The required gradient is an average over the procedure, so yes it may drop off in the turns
.. but how are you intending to allow for such things ? The main problem with the real world is that the pointy bits of the profile have a nasty habit of sticking through the gradient surface and hitting a hard bit ... averages give some guidance but don't hack it at close quarters.
Also, before we get too anxious, keep in mind that the gross/net decrement gives a fairly big delta the further we get away from the runway so it's not all gloom and doom .. but once the lawyers get a hold of it, they do tend to get introspective about black and white, rather than the real world of shades of grey.
(a) Your company will have produced ...
Most do, some don't .. it is good practice for the commander to know which sort of company it is for which he/she flies.
(b) If you are able (performance-wise) to follow the normal SID and the required climb profile it is advisable to fly that since ATC does not know your EOSID
Fair comment - but the ops eng folk need to have looked at this topic in detail to make sure that tracking is feasible from the approach and that net profiles, especially third segment acceleration and turn radius is OK. That is to say, not appropriate for the commander to figure out on the fly.
(c) To use a certain procedure you have to meet the required climb gradients
Do keep in mind that gradients are only part of the problem. Configuration changes, gross/net decrements, and turn gradient delta/radius complicate things.
(d) .. the commander may always decide differently ..
But do make sure you have a good story for the Enquiry. Be very wary of continuing visually in tiger country areas - the gradients are very shallow and not amenable to winging it as we go.
(e) You may get your engine failure at 3000' with the engine out procedure behind you... but will you make it above the 12000' peak ahead of you?
A good ops engineer will have looked at ALL the possibilities until you are above all relevant terrain. Unfortunately, not all ops engineers are operationally savvy and, if this is the case, the exercise should involve a joint ops eng/flight standards liaison.
(f) The point is that you only have to meet the gradient ..
Not adequate. Please do keep configuration changes and turn deltas/radius in mind.
(g) I would also commend looking at a topo chart if you'd be unable to meet the gradient
Topos give useful background - particularly in respect of the big picture stuff. They are not too bad at telling you that there is a BIG hill here or there ... however, they are NOT terribly accurate or useful when it comes to figuring critical net clearances.
Further the sorts of errors which creep into the topo world are legion.
In the real world of ops engineering we use the topo to figure out where the difficult bits might be and then, if it is really critical, a couple of fine chaps/chapesses draw the short straw and have a fun day out in the bush with a theodolite and associated kit.
(h) When visual a Mk I eyeball is also a useful tool.
So long as it is limited to staying away from big hills in the same way that we eyeball staying away from thunderstorms. Mk I eyeball is pretty useless for scraping over ridges and such like OEI.
(i) Are you aware that your gradient diminishes in turns
Something similar to operating at higher weights (load factor effect). The specific sums might vary a bit but, typically, expect something in the region of 0.6 - 1.0 percent decrement, give or take.
(j) It boils down to never go anywhere in an a/c that your brain hasn't been first.
That's not a bad philosophy ..
(k) The required gradient is an average over the procedure, so yes it may drop off in the turns
.. but how are you intending to allow for such things ? The main problem with the real world is that the pointy bits of the profile have a nasty habit of sticking through the gradient surface and hitting a hard bit ... averages give some guidance but don't hack it at close quarters.
Also, before we get too anxious, keep in mind that the gross/net decrement gives a fairly big delta the further we get away from the runway so it's not all gloom and doom .. but once the lawyers get a hold of it, they do tend to get introspective about black and white, rather than the real world of shades of grey.
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Since 90% of all approaches are in VMC conditions rather than spending 5 minutes going over every possible missed approach with one engine I just say right turn to downwind and land. Bogota is a good example of that. Their missed approaches change constantly depending on where you are so if is VMC just keep it simple and don't bore your FO with BS that doesn't matter.
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I just say right turn to downwind and land
Have no problem with that idea if you actually land.
Now, if the runway becomes blocked while you are on late final (reason doesn't matter, nor does the consideration that such things are not commonplace) and, for whatever reason, you can't land .. what are you intending to do ? ... hovering on the glidepath for a while to think things over isn't an option in an airliner.
Not much different philosophically to saying that, given the reliability of modern engines, why bother with all this EFATO stuff .. just go ahead and takeoff AEO.
Have no problem with that idea if you actually land.
Now, if the runway becomes blocked while you are on late final (reason doesn't matter, nor does the consideration that such things are not commonplace) and, for whatever reason, you can't land .. what are you intending to do ? ... hovering on the glidepath for a while to think things over isn't an option in an airliner.
Not much different philosophically to saying that, given the reliability of modern engines, why bother with all this EFATO stuff .. just go ahead and takeoff AEO.
I would have thought that if you briefed the circuit visually for the initial landing then it would also be ok for a s/e missed approach proceedure. Am I missing something there?
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Bogota is a good example of that. Their missed approaches change constantly depending on where you are so if is VMC just keep it simple and don't bore your FO with BS that doesn't matter.
The required gradient is an average over the procedure, so yes it may drop off in the turns
.. but how are you intending to allow for such things ?
.. but how are you intending to allow for such things ?
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J.T.:
That is often the only way to sort it all out.
Alas, a popular performance vendor in the U.S. is not even using topos, rather the data derived from the Space Shuttle mission. I have those data as an adjunct on my GIS program. Fairly good for planning, but that is about it. The U.S. 1:24000 topos are generally good (excluding Alaska) but still need at least a Day VFR flight inspection.
It isn't happening with some exceptions.
Also, pilots seem quite confused about visual avoidance providing an "out." OEI flight paths are weather independent as you well know. If they must be flown it is all the same, DAY VFR, Day IMC, etc.
In the real world of ops engineering we use the topo to figure out where the difficult bits might be and then, if it is really critical, a couple of fine chaps/chapesses draw the short straw and have a fun day out in the bush with a theodolite and associated kit.
Alas, a popular performance vendor in the U.S. is not even using topos, rather the data derived from the Space Shuttle mission. I have those data as an adjunct on my GIS program. Fairly good for planning, but that is about it. The U.S. 1:24000 topos are generally good (excluding Alaska) but still need at least a Day VFR flight inspection.
It isn't happening with some exceptions.
Also, pilots seem quite confused about visual avoidance providing an "out." OEI flight paths are weather independent as you well know. If they must be flown it is all the same, DAY VFR, Day IMC, etc.
Moderator
Am I missing something there?
I think that might be the case.
Picture yourself down low over the runway when you need to go to the miss ... think, for instance, twin perhaps at 2.5-3.0 percent gross on the day. That's not much climb capability. How were you proposing to ensure that your bird misses the hard bits during the miss ?
What you need is a chart like this one from the Flight Manual for my twin
Looking at Capn Bloggs' fine graphic, I should have qualified my previous decrement figures to be relevant to 15 deg bank which is the typical figure for OEI turns.
1:24000 topos are generally good
.. but still far too coarse for detailed work. Best stuff I have found are the occasional very detailed charts down to 1:2000 - 1:5000. Wonderful detail for the ground. HOWEVER, the main problem is that one can't rely on any chart for tree heights and similar .. these it takes a walk in the park to have a looksee.
Sat derived elevations are useful, especially for areas where there are no published survey charts. but they only go so far. Ends up being a case of horses for courses .. if the hill/saddle/etc clearly is not too critical, ROM estimates for vegetation are fine .. if the clearance is critical, a theodolite or inclinometer, depending on the location with respect to the runway and Type, ends up being the only sensible way to cover one's delicate bits for the possible subsequent Enquiry.
still need at least a Day VFR flight inspection
.. often the reasonable cost solution for those intermediate accuracy problems but, again, not much good for critical situations .. although, invariably, great fun.
Can recall a wonderful day, many, many years ago, spent in a largish (and very noisy) four-engined turboprop machine running simulated OEI profiles from the runway head (and from a very low height) at a particular seaside aerodrome only because the Regulator's flight standards representative didn't understand much about what was what.
My mate, Bazza, was driving from the RHS and Dunc (the Regulator man) and I were in the jumpseats. As I recall Denis was in the LHS and beaming widely the whole time.
At one point during proceedings, Dunc observed "I don't really understand why we are doing this", Denis was beaming fondly, while Bazza was having an absolute ball. Me ?, well I was quite bemused as the whole exercise didn't really achieve much at all other than burning lots of kero, would have been far cheaper in an Aztruck or similar ... but it was absolutely great fun and must have annoyed the living daylights out of the locals until we all got bored and flew off back home.
.. I'm not sure if it's a case of all the fun having gone out of life in the present PC world .. or am I just becoming a boring old phart way past his use-by date ?
pilots seem quite confused about visual avoidance providing an "out."
A commonly seen fallacy. Works fine if you have one big hill and you can avoid it by a suitable margin and you are above all other terrain. However, any attempt to play tactical battlefield helicopters OEI in anger is a recipe for disaster - the gradients are too small for the human brain to figure on the fly and, when it comes to figuring differences between small quantities, the brain doesn't appear to have a good track record.
I think that might be the case.
Picture yourself down low over the runway when you need to go to the miss ... think, for instance, twin perhaps at 2.5-3.0 percent gross on the day. That's not much climb capability. How were you proposing to ensure that your bird misses the hard bits during the miss ?
What you need is a chart like this one from the Flight Manual for my twin
Looking at Capn Bloggs' fine graphic, I should have qualified my previous decrement figures to be relevant to 15 deg bank which is the typical figure for OEI turns.
1:24000 topos are generally good
.. but still far too coarse for detailed work. Best stuff I have found are the occasional very detailed charts down to 1:2000 - 1:5000. Wonderful detail for the ground. HOWEVER, the main problem is that one can't rely on any chart for tree heights and similar .. these it takes a walk in the park to have a looksee.
Sat derived elevations are useful, especially for areas where there are no published survey charts. but they only go so far. Ends up being a case of horses for courses .. if the hill/saddle/etc clearly is not too critical, ROM estimates for vegetation are fine .. if the clearance is critical, a theodolite or inclinometer, depending on the location with respect to the runway and Type, ends up being the only sensible way to cover one's delicate bits for the possible subsequent Enquiry.
still need at least a Day VFR flight inspection
.. often the reasonable cost solution for those intermediate accuracy problems but, again, not much good for critical situations .. although, invariably, great fun.
Can recall a wonderful day, many, many years ago, spent in a largish (and very noisy) four-engined turboprop machine running simulated OEI profiles from the runway head (and from a very low height) at a particular seaside aerodrome only because the Regulator's flight standards representative didn't understand much about what was what.
My mate, Bazza, was driving from the RHS and Dunc (the Regulator man) and I were in the jumpseats. As I recall Denis was in the LHS and beaming widely the whole time.
At one point during proceedings, Dunc observed "I don't really understand why we are doing this", Denis was beaming fondly, while Bazza was having an absolute ball. Me ?, well I was quite bemused as the whole exercise didn't really achieve much at all other than burning lots of kero, would have been far cheaper in an Aztruck or similar ... but it was absolutely great fun and must have annoyed the living daylights out of the locals until we all got bored and flew off back home.
.. I'm not sure if it's a case of all the fun having gone out of life in the present PC world .. or am I just becoming a boring old phart way past his use-by date ?
pilots seem quite confused about visual avoidance providing an "out."
A commonly seen fallacy. Works fine if you have one big hill and you can avoid it by a suitable margin and you are above all other terrain. However, any attempt to play tactical battlefield helicopters OEI in anger is a recipe for disaster - the gradients are too small for the human brain to figure on the fly and, when it comes to figuring differences between small quantities, the brain doesn't appear to have a good track record.
