V1 Cut obstacle clearance.
J_T
I might add OS's cautions about take-off power limitations, that acceleration heights/segments on SIDs are not factored and it will probably be very limiting in most planes in most situations. Lastly, in some planes computing an accurate OEI climb gradient is not an easy trick, either.
Probably not a factor in most planes, but I (and I'll bet you, too) have flown planes that can be easily challenged at some airports in the AEO case. And I don't Aspen, Colorado only.
GF
Can we use the SID single engine ?
Probably not a factor in most planes, but I (and I'll bet you, too) have flown planes that can be easily challenged at some airports in the AEO case. And I don't Aspen, Colorado only.
GF
Moderator
Oh dear .. appears I have been a tad lax again with my words. Perhaps I should have said something like .. one can use the SID OEI but it is no different to working out your own escape .. you still have to get all the relevant obstacle data and do all the sums and work out the limiting case for the takeoff to determine the relevant RTOW. The only advantage of the SID is that it fits in with ATC ... if may very well not give you anything like an acceptable commercial RTOW...
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I'm in complete agreement with J_T, yes, you can use the normal All Engine SIDs for OEI procedures, but there is a VERY large caveat!
The SIDs are for Gross Performance, and "reverse engineering" can be applied to establish the actual obstacles considered when creating the SID, then you can apply the OEI data. First part of problem solved.
Now comes the big one. If we use the "reverse engineered" SID data for 2nd segment, what is the Minimum Acceleration Altitude (MAA)? Assuming that we are using the SID data, and nothing else, we must assume the highest obstacle to be 1000 feet below the MSA. Last night, I operated to an airport with MSA of 5500 Ft in the Takeoff area, that means the worst obstacle was 4500 Ft. A 4500 Ft highest obstacle, after applying Gross/Net corrections for OEI means a MAA of 6785 Ft, or MSA of 5500 Ft as that is a safe altitude. That is an impossible "ask" for an aircraft with even a 10 minute limitation on Takeoff thrust.
The only alternative is to establish a "OEI break off" point for the SID, so, out come the survey charts, which nobody carries in the cockpit. We're screwed.
I'm guilty of converting a few SIDs to OEI procedures, NOT as a standard procedure, but to cover that insideous situation where an early SID turn followed by an engine failure puts the aircraft in "No Man's Land". If the pilot cannot accept the SID with it's attendant RTOW penalties, then refuse it, and advise ATC of the alternative normal OEISID requirement!
As I've proposed in this and other forums, we DO need "government Issue" OEISIDs at ALL airports, even if conservative for some operators. The right to develop alternative OEISIDs must be preserved as an alternative - more work for you Oz_Expat!
I note that one of the contributors identified "J", it wasn't me your honour, "J" has a far bigger litigation budget than I do!!!!!!!!!!!!!!!
VERY IMPORTANT NOTE - A common question on these forums is "Can I use the SID following Engine Failure?" Categorically, the answer is NO, unless (except in a few safe cases) the SID is reverse engineered to FAR 25 criteria, and a suitable break-off point established
Regards,
Old Smokey
The SIDs are for Gross Performance, and "reverse engineering" can be applied to establish the actual obstacles considered when creating the SID, then you can apply the OEI data. First part of problem solved.
Now comes the big one. If we use the "reverse engineered" SID data for 2nd segment, what is the Minimum Acceleration Altitude (MAA)? Assuming that we are using the SID data, and nothing else, we must assume the highest obstacle to be 1000 feet below the MSA. Last night, I operated to an airport with MSA of 5500 Ft in the Takeoff area, that means the worst obstacle was 4500 Ft. A 4500 Ft highest obstacle, after applying Gross/Net corrections for OEI means a MAA of 6785 Ft, or MSA of 5500 Ft as that is a safe altitude. That is an impossible "ask" for an aircraft with even a 10 minute limitation on Takeoff thrust.
The only alternative is to establish a "OEI break off" point for the SID, so, out come the survey charts, which nobody carries in the cockpit. We're screwed.
I'm guilty of converting a few SIDs to OEI procedures, NOT as a standard procedure, but to cover that insideous situation where an early SID turn followed by an engine failure puts the aircraft in "No Man's Land". If the pilot cannot accept the SID with it's attendant RTOW penalties, then refuse it, and advise ATC of the alternative normal OEISID requirement!
As I've proposed in this and other forums, we DO need "government Issue" OEISIDs at ALL airports, even if conservative for some operators. The right to develop alternative OEISIDs must be preserved as an alternative - more work for you Oz_Expat!
I note that one of the contributors identified "J", it wasn't me your honour, "J" has a far bigger litigation budget than I do!!!!!!!!!!!!!!!
VERY IMPORTANT NOTE - A common question on these forums is "Can I use the SID following Engine Failure?" Categorically, the answer is NO, unless (except in a few safe cases) the SID is reverse engineered to FAR 25 criteria, and a suitable break-off point established
Regards,
Old Smokey
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Old Smokey,
I like the idea of a generic EOSID for "general" issue, reserving the right for the bigger players to also create their own more specific charts for various reasons (including payload of course!).
As a first step, however, would it be fair to say that the aerodrome operators should be required to be able to supply, quickly, the required detailed surveys that are necessary to generate the procedures?
It seems that a lot of this survey detail is just not readily available, which would certainly dissuade a smaller operator from being able to come up with plans quickly and efficiently.
Question the 2nd - Do your airlines share their E/O SIDS and procedures with the local ATC's? Obviously some places in the world its best to keep the trap shut as more info would just cause confusion, but there are plenty of ATC departments who I'm sure would be interested to know roughly what we plan to do, before we actually have to do it.
I like the idea of a generic EOSID for "general" issue, reserving the right for the bigger players to also create their own more specific charts for various reasons (including payload of course!).
As a first step, however, would it be fair to say that the aerodrome operators should be required to be able to supply, quickly, the required detailed surveys that are necessary to generate the procedures?
It seems that a lot of this survey detail is just not readily available, which would certainly dissuade a smaller operator from being able to come up with plans quickly and efficiently.
Question the 2nd - Do your airlines share their E/O SIDS and procedures with the local ATC's? Obviously some places in the world its best to keep the trap shut as more info would just cause confusion, but there are plenty of ATC departments who I'm sure would be interested to know roughly what we plan to do, before we actually have to do it.
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A good response A Comfy Chair, I agree with all that you say, but the "quick" availability of the requisite data (except for Straight Ahead) is not all that easy to come by from the local authorities. The data is certainly available, but the time taken to acquire it may extend to weeks or even months, so much for "fast" data.
There's very good high quality digital data that exists for the entire planet, but the next question arises, does the regulatory authority accept it as an accurate and approved source?
When creating OEISIDs, I use all of the approved data, and then check against all other data (including non-approved Google Earth) for any other obstacles that MAY be there. Once or twice, it has paid off. Literally, you can leave no stone unturned (pun intended).
To answer your second question, yes, I do personally visit each ATC unit and brief them on our intended procedures following engine failure, leaving them with copies of the particular procedures in map form. It has surprised me when many (most) have commented that this is the first such visit that they've had, so apparently it's not common practice. (Try doing it in Russian).
Regards,
Old Smokey
There's very good high quality digital data that exists for the entire planet, but the next question arises, does the regulatory authority accept it as an accurate and approved source?
When creating OEISIDs, I use all of the approved data, and then check against all other data (including non-approved Google Earth) for any other obstacles that MAY be there. Once or twice, it has paid off. Literally, you can leave no stone unturned (pun intended).
To answer your second question, yes, I do personally visit each ATC unit and brief them on our intended procedures following engine failure, leaving them with copies of the particular procedures in map form. It has surprised me when many (most) have commented that this is the first such visit that they've had, so apparently it's not common practice. (Try doing it in Russian).
Regards,
Old Smokey
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about CAO 20.7.1b
O_S and J_T,
With no intention to divert the thread, can I throw in the following:
My understanding of the meaning of paras 12.1B and 12.4 is that the planning must go to either MSA if there is no navaid or the enroute OCA (1360'?) in the safety height containment area where there is a navaid.
I also understand that AIP is only a place to publish the effect of proper legislative instruments and cannot mandate anything in its own right. Any statement in AIP about takeoff performance and obstacle clearance would only be based on the regulators view of the effect of CAO 20.7.1b or any amending instruments.
Stay Alive...
With no intention to divert the thread, can I throw in the following:
My understanding of the meaning of paras 12.1B and 12.4 is that the planning must go to either MSA if there is no navaid or the enroute OCA (1360'?) in the safety height containment area where there is a navaid.
I also understand that AIP is only a place to publish the effect of proper legislative instruments and cannot mandate anything in its own right. Any statement in AIP about takeoff performance and obstacle clearance would only be based on the regulators view of the effect of CAO 20.7.1b or any amending instruments.
Stay Alive...
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I'm guilty of converting a few SIDs to OEI procedures, NOT as a standard procedure, but to cover that insideous situation where an early SID turn followed by an engine failure puts the aircraft in "No Man's Land".
P
OS
While I understand Gross/Net as applied to climb gradient, could you expound on Gross/Net in regards to MAA?
Thanks, GF
Last night, I operated to an airport with MSA of 5500 Ft in the Takeoff area, that means the worst obstacle was 4500 Ft. A 4500 Ft highest obstacle, after applying Gross/Net corrections for OEI means a MAA of 6785 Ft, or MSA of 5500 Ft as that is a safe altitude.
Thanks, GF
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4Dogs,
Much better that you leave that one to John_Tullamarine, he's an extraordinary engineer, but just as extraordinary in twisting the legislator's tails, something I'm not good at.
Permafrost_ATPL,
You describe the nightmare scenario. I'm well familiar with ZRH, and as I read your post I get goose bumps. ZRH is definately NOT a good place to turn in ANY safe direction following engine failure on the RWY 28 Left-Turn SID (or just about any of the ZRH SIDs for that matter). I don't want to sound as though I'm beating my own drum, but I've advocated over hundreds of posts in these forums that if SIDs are to be used - Fine, but FORMALLY establish procedures for MAA and a "break-off" point from the SID following engine failure. It's NOT difficult to do, it just costs your operator extra money. I do it for all of the "critical" SIDs that my clients use. I define critical as a turn during the SID before the aircraft has achieved a safe altitude should an engine fail after the SID turn.
galaxy flyer,
The principals involved in establishing MAA and the length of the 3rd segment are quite similar to the protocols used for Gross Vs Net performance in the 2nd segment. Using a 2 engined aircraft as the example, Gross climb gradient is estableshed by flight testing, and arbitrarily degraded by 0.8% to achieve the Net performance. (3 and 4 engined aircraft use the same principle, but the increments differ).
As an example, consider a Sea Level Runway which requires a 2.0% climb gradient to clear a 2nd segment obstacle. The aircraft should, if in new condition and flown by the Test Pilot, achieve an actual Gross Gradient of 2.8%. Therefore, the ratio of Gross to Net is 2.8 : 2.0, a factor of 1.4 (a comfortable margin).
Now, let's say that the highest obstacle in the Takeoff Area is 1000 Ft above the runway. The Net flight path need only clear this obstacle by 35 ft, not acceptable to anyone! Thus, the Minimum Acceleration Altitude (MAA or 3rd Segment Altitude) is factored in exactly the same way as was the 2nd segment glimb, i.e. 2.8 : 2.0 or 1.4. The "base" MAA will then be 1000 X 1.4 or 1400 Ft. To this is added the screen height of 35 ft (or 50 ft for a turning manoeuvre) plus the Airport elevation, yielding a MAA of 1435 ft (as we used a Sea Level Runway). If you want to put this into a long-hand formula -
MAA = Obstacle Height above the lowest point on the Runway X (Required Net Gradient + 0.8%) divided by Required Net Gradient + Screen Height + Highest Runway Elevation.
3rd Segment horizontal Distance is similarly factored. If the actual (Gross) 3rd Segment distance was, for example, 20,000 M, this is multiplied by the same factor (1.4 used here) to achieve a Net 3rd Segment distance of 20,000 X 1.4 = 28,000 M.
After all of this, you're PROBABLY still below MSA, so you'd better go lookin' for a safe place to climb to MSA. A FAR 25 principle developed "safe climb" holding pattern is this person's preferred choice here.
Sadly, there are still people "out there" who want to 'eye-ball' it!
A personal viewpoint - The Gross Vs Net margins for the continued Takeoff following engine failure are generous. With FPA / FPV displays available on most modern aircraft, I've observed even average pilots tend to fly closer to the "Test Pilot's" Gross gradient than the Net. It lends great strength to the GO case, as the margins for Accelerate Stop are much much less.
Regards,
Old Smokey
Much better that you leave that one to John_Tullamarine, he's an extraordinary engineer, but just as extraordinary in twisting the legislator's tails, something I'm not good at.
Permafrost_ATPL,
You describe the nightmare scenario. I'm well familiar with ZRH, and as I read your post I get goose bumps. ZRH is definately NOT a good place to turn in ANY safe direction following engine failure on the RWY 28 Left-Turn SID (or just about any of the ZRH SIDs for that matter). I don't want to sound as though I'm beating my own drum, but I've advocated over hundreds of posts in these forums that if SIDs are to be used - Fine, but FORMALLY establish procedures for MAA and a "break-off" point from the SID following engine failure. It's NOT difficult to do, it just costs your operator extra money. I do it for all of the "critical" SIDs that my clients use. I define critical as a turn during the SID before the aircraft has achieved a safe altitude should an engine fail after the SID turn.
galaxy flyer,
The principals involved in establishing MAA and the length of the 3rd segment are quite similar to the protocols used for Gross Vs Net performance in the 2nd segment. Using a 2 engined aircraft as the example, Gross climb gradient is estableshed by flight testing, and arbitrarily degraded by 0.8% to achieve the Net performance. (3 and 4 engined aircraft use the same principle, but the increments differ).
As an example, consider a Sea Level Runway which requires a 2.0% climb gradient to clear a 2nd segment obstacle. The aircraft should, if in new condition and flown by the Test Pilot, achieve an actual Gross Gradient of 2.8%. Therefore, the ratio of Gross to Net is 2.8 : 2.0, a factor of 1.4 (a comfortable margin).
Now, let's say that the highest obstacle in the Takeoff Area is 1000 Ft above the runway. The Net flight path need only clear this obstacle by 35 ft, not acceptable to anyone! Thus, the Minimum Acceleration Altitude (MAA or 3rd Segment Altitude) is factored in exactly the same way as was the 2nd segment glimb, i.e. 2.8 : 2.0 or 1.4. The "base" MAA will then be 1000 X 1.4 or 1400 Ft. To this is added the screen height of 35 ft (or 50 ft for a turning manoeuvre) plus the Airport elevation, yielding a MAA of 1435 ft (as we used a Sea Level Runway). If you want to put this into a long-hand formula -
MAA = Obstacle Height above the lowest point on the Runway X (Required Net Gradient + 0.8%) divided by Required Net Gradient + Screen Height + Highest Runway Elevation.
3rd Segment horizontal Distance is similarly factored. If the actual (Gross) 3rd Segment distance was, for example, 20,000 M, this is multiplied by the same factor (1.4 used here) to achieve a Net 3rd Segment distance of 20,000 X 1.4 = 28,000 M.
After all of this, you're PROBABLY still below MSA, so you'd better go lookin' for a safe place to climb to MSA. A FAR 25 principle developed "safe climb" holding pattern is this person's preferred choice here.
Sadly, there are still people "out there" who want to 'eye-ball' it!
A personal viewpoint - The Gross Vs Net margins for the continued Takeoff following engine failure are generous. With FPA / FPV displays available on most modern aircraft, I've observed even average pilots tend to fly closer to the "Test Pilot's" Gross gradient than the Net. It lends great strength to the GO case, as the margins for Accelerate Stop are much much less.
Regards,
Old Smokey
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If I may throw in a curved ball to OS which is slightly off thread but neverthless in the same vein:
So we have lost an engine in a twin jet just after V1 at, say ZRH, we successfully negotiate the EO SID to the HP and prepare for an ILS - hopefully to our runway of choice - OEI at or just under MLW (3 changes of landing R/W in 20 mins last night at ZRH).
Unfortunately, for reasons unthinkable, we have to G/A from MDA/DA. I don't believe there are any notes on the J plates concerning min alts for level acceleration and so my Company would have me follow the standard MAP and accelerate at 1000agl
Any thoughts on that?
Cheers all
mcdhu
So we have lost an engine in a twin jet just after V1 at, say ZRH, we successfully negotiate the EO SID to the HP and prepare for an ILS - hopefully to our runway of choice - OEI at or just under MLW (3 changes of landing R/W in 20 mins last night at ZRH).
Unfortunately, for reasons unthinkable, we have to G/A from MDA/DA. I don't believe there are any notes on the J plates concerning min alts for level acceleration and so my Company would have me follow the standard MAP and accelerate at 1000agl
Any thoughts on that?
Cheers all
mcdhu
This is a very informative thread:
For further information is seemed to have made an error OS
but interestingly enough the Flight Standards Branch in the USA offers numerous digital productions for free download or on CD ROM
DACS is a different product, but the formatting is the most useful [ARINC 424] for airway/navaid dat and all referenced to WGS84 geodectic standards.
Here's the direct reference from the FAA AIM for anyone interested:
e. Digital Products.
1. The Digital Aeronautical Information CD (DAICD). The DAICD is a combination of the NAVAID Digital Data File, the Digital Chart Supplement, and the Digital Obstacle File on one Compact Disk. These three digital products are no longer sold separately. The files are updated every 56 days and are available by subscription only.
(a) The NAVAID Digital Data File. This file contains a current listing of NAVAIDs that are compatible with the National Airspace System. This file contains all NAVAIDs including ILS and its components, in the U.S., Puerto Rico, and the Virgin Islands plus bordering facilities in Canada, Mexico, and the Atlantic and Pacific areas.
(b) The Digital Obstacle File. This file describes all obstacles of interest to aviation users in the U.S., with limited coverage of the Pacific, Caribbean, Canada, and Mexico. The obstacles are assigned unique numerical identifiers, accuracy codes, and listed in order of ascending latitude within each state or area.
(c) The Digital Aeronautical Chart Supplement (DACS). The DACS is specifically designed to provide digital airspace data not otherwise readily available. The supplement includes a Change Notice for IAPFIX.dat at the mid-point between revisions. The Change Notice is available only by free download from the NACO website.
The DACS individual data files are:
ENHIGH.DAT: High altitude airways (conterminous U.S.)
ENLOW.DAT: Low altitude airways (conterminous U.S.)
IAPFIX.DAT: Selected instrument approach procedure NAVAID and fix data.
MTRFIX.DAT: Military training routes data.
ALHIGH.DAT: Alaska high altitude airways data.
ALLOW.DAT: Alaska low altitude airways data.
PR.DAT: Puerto Rico airways data.
HAWAII.DAT: Hawaii airways data.
BAHAMA.DAT: Bahamas routes data.
OCEANIC.DAT: Oceanic routes data.
STARS.DAT: Standard terminal arrivals data.
DP.DAT: Instrument departure procedures data.
LOPREF.DAT: Preferred low altitude IFR routes data.
HIPREF.DAT: Preferred high altitude IFR routes data.
ARF.DAT: Air route radar facilities data.
ASR.DAT: Airport surveillance radar facilities data.
2. The National Flight Database (NFD) (ARINC 424 [Ver 13 & 15]). The NFD is a basic digital dataset, modeled to an international standard, which can be used as a basis to support GPS navigation. Initial data elements included are: Airport and Helicopter Records, VHF and NDB Navigation aids, en route waypoints and airways. Additional data elements will be added in subsequent releases to include: departure procedures, standard terminal arrivals, and GPS/RNAV instrument approach procedures. The database is updated every 28 days. The data is available by subscription only and is distributed on CD-ROM or by ftp download.
3. Sectional Raster Aeronautical Charts (SRAC). These digital VFR charts are geo-referenced scanned images of FAA sectional charts. Additional digital data may easily be overlaid on the raster image using commonly available Geographic Information System software. Data such as weather, temporary flight restrictions, obstacles, or other geospatial data can be combined with SRAC data to support a variety of needs. Most SRACs are provided in two halves, a north side and a south side. The file resolution is 200 dots per inch and the data is 8-bit color. The data is provided as a GeoTIFF and distributed on DVD-R media. The root mean square error of the transformation will not exceed two pixels. SRACs DVDs are updated every 28 days and are available by subscription only.
MCHDU I've always wondered myself if a good OEI procedure will allow for an OEI LDG climb, in spite of the '8 sec rule for climb thrust?
J_T MUTT and OS
The way you guys do this stuff; I don't believe is written down in any publication
'Principles and Practice,...Art Science and Technique' [ Rev. R Lacanster and T. Shimizu]
but I would not mind some assistance in aquiring the 'Boeing
engineers Book'
Sorry,.... most of my posts are made on the Newest Comador 64
PA
For further information is seemed to have made an error OS
but interestingly enough the Flight Standards Branch in the USA offers numerous digital productions for free download or on CD ROM
DACS is a different product, but the formatting is the most useful [ARINC 424] for airway/navaid dat and all referenced to WGS84 geodectic standards.
Here's the direct reference from the FAA AIM for anyone interested:
e. Digital Products.
1. The Digital Aeronautical Information CD (DAICD). The DAICD is a combination of the NAVAID Digital Data File, the Digital Chart Supplement, and the Digital Obstacle File on one Compact Disk. These three digital products are no longer sold separately. The files are updated every 56 days and are available by subscription only.
(a) The NAVAID Digital Data File. This file contains a current listing of NAVAIDs that are compatible with the National Airspace System. This file contains all NAVAIDs including ILS and its components, in the U.S., Puerto Rico, and the Virgin Islands plus bordering facilities in Canada, Mexico, and the Atlantic and Pacific areas.
(b) The Digital Obstacle File. This file describes all obstacles of interest to aviation users in the U.S., with limited coverage of the Pacific, Caribbean, Canada, and Mexico. The obstacles are assigned unique numerical identifiers, accuracy codes, and listed in order of ascending latitude within each state or area.
(c) The Digital Aeronautical Chart Supplement (DACS). The DACS is specifically designed to provide digital airspace data not otherwise readily available. The supplement includes a Change Notice for IAPFIX.dat at the mid-point between revisions. The Change Notice is available only by free download from the NACO website.
The DACS individual data files are:
ENHIGH.DAT: High altitude airways (conterminous U.S.)
ENLOW.DAT: Low altitude airways (conterminous U.S.)
IAPFIX.DAT: Selected instrument approach procedure NAVAID and fix data.
MTRFIX.DAT: Military training routes data.
ALHIGH.DAT: Alaska high altitude airways data.
ALLOW.DAT: Alaska low altitude airways data.
PR.DAT: Puerto Rico airways data.
HAWAII.DAT: Hawaii airways data.
BAHAMA.DAT: Bahamas routes data.
OCEANIC.DAT: Oceanic routes data.
STARS.DAT: Standard terminal arrivals data.
DP.DAT: Instrument departure procedures data.
LOPREF.DAT: Preferred low altitude IFR routes data.
HIPREF.DAT: Preferred high altitude IFR routes data.
ARF.DAT: Air route radar facilities data.
ASR.DAT: Airport surveillance radar facilities data.
2. The National Flight Database (NFD) (ARINC 424 [Ver 13 & 15]). The NFD is a basic digital dataset, modeled to an international standard, which can be used as a basis to support GPS navigation. Initial data elements included are: Airport and Helicopter Records, VHF and NDB Navigation aids, en route waypoints and airways. Additional data elements will be added in subsequent releases to include: departure procedures, standard terminal arrivals, and GPS/RNAV instrument approach procedures. The database is updated every 28 days. The data is available by subscription only and is distributed on CD-ROM or by ftp download.
3. Sectional Raster Aeronautical Charts (SRAC). These digital VFR charts are geo-referenced scanned images of FAA sectional charts. Additional digital data may easily be overlaid on the raster image using commonly available Geographic Information System software. Data such as weather, temporary flight restrictions, obstacles, or other geospatial data can be combined with SRAC data to support a variety of needs. Most SRACs are provided in two halves, a north side and a south side. The file resolution is 200 dots per inch and the data is 8-bit color. The data is provided as a GeoTIFF and distributed on DVD-R media. The root mean square error of the transformation will not exceed two pixels. SRACs DVDs are updated every 28 days and are available by subscription only.
MCHDU I've always wondered myself if a good OEI procedure will allow for an OEI LDG climb, in spite of the '8 sec rule for climb thrust?
J_T MUTT and OS
The way you guys do this stuff; I don't believe is written down in any publication
'Principles and Practice,...Art Science and Technique' [ Rev. R Lacanster and T. Shimizu]
but I would not mind some assistance in aquiring the 'Boeing
engineers Book'
Sorry,.... most of my posts are made on the Newest Comador 64
PA
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Thanks Old Smokey. And very interesting answer to galaxy flyer's question - definitely one for the Bookmark folder.
Now looking forward to what you have to say about mcdhu's question Been wondering about that myself...
P
Now looking forward to what you have to say about mcdhu's question
Been wondering about that myself...P
Moderator
Great to see that this thread has fired up a good deal of interest .. some comments ..
would it be fair to say that the aerodrome operators should be required to be able to supply, quickly, the required detailed surveys that are necessary to generate the procedures?
I suggest not. Depending on the jurisdiction, the owners will provide that which is required (and this costs someone - ultimately the operators - dollars). At present, one might see one or more of Type A (or its diminutives), Type B, Type C (I can't ever recall having seen one of these) and several other sets of OLS data. Given the variety of performance needs for a variety of aircraft Types, unless the surroundings are simple (eg a ridge or big hill and not much more) it would become a tad messy ... Probably better for the operator (or operators in conjunction/service providers) to do the work and contain the costs to the end users.
The Oz aerodrome MOS is a useful reference document for those who fancy a little light bedtime reading ..
It seems that a lot of this survey detail is just not readily available
For most places, the problems are relatively easy to determine and address. Certainly, one needs to have cultivated a range of suitable contacts for obstacle data and, on occasion, one needs to throw the theodolite over the shoulder and go forth into the hinterland .. at the end of the day it is just a matter of the will to do the work .. and this comes down to corporate risk assessment for the operator.
Do your airlines share their E/O SIDS and procedures with the local ATC's?
I believe that most don't. Some of us will make sure that any unusual escapes are notified to ATC or equivalent. Clearly, if the procedure is compatible with "normal" traffic handling, the need is somewhat less.
the meaning of paras 12.1B and 12.4 is that the planning must go to either MSA if there is no navaid or the enroute OCA (1360'?) in the safety height containment area where there is a navaid.
Oz CAO 20.7.1b has always been an interesting animal. It is similar to the US 23/25-91/121 type of approach where there is a separation of airworthiness and operational standards. In the case of the Australian vehicles (historically) a few gremlins sneaked through the process with the result that we have had some discrepancies over the years.
For the younger folk who don't recall the "old" ANOs etc., the airworthiness bits were in ANO 101.5 and 6 for the heavies with the operational data in ANO 20.7.1B. 101.5/6 largely called up the relevant UK/US standards .. if we go back further to the times of ANOs which had more subordinate identifying numbers than you could poke a stick at, we would find detailed standards. These later became CAOs and, in line with the harmonisation processes, the Australian airworthiness vehicles were dumped without ceremony in the WPB ... This process has had both its good and bad points for the local Industry.
Functionally, how one implements the requirement depends on how much work you want to throw at the problem. In most cases use of declared data, such as MSA saves some time and effort.
I also understand that AIP is only a place to publish
A question for the legal folk to offer comment ...
However, it has always been understood generally that a requirement is mandated via the Act, Regs and Orders with notes and AIP providing expanded information. However, the potential risk is that, if one were to depart from an AIP "requirement", then one would need to be very certain that the requirement wasn't glued to a Reg, etc. The easier process is to adopt the AIP as mandatory .. unless the context clearly indicates an option. Just my opinion.
I was far from convinced that would keep us clear of obstacles! Surely we would have been better off requesting a SID which at least went it the same overall direction as the SE procedure?
Presuming that the operator has done the sums, then the matter should be prescribed in SOP. If SOP is a bit rubbery, then one should enquire of the operator's management what the rubbery bits really mean. At the end of the day one can always decline the SID if the concern is considered significant and reasonable.
I've observed even average pilots tend to fly closer to the "Test Pilot's" Gross gradient than the Net.
I've no problem with that observation. However, and this goes back to earlier steam driven aircraft, the then DCA's Ian C did a study (TAA, as I recall - I have no doubt that the results would have been similar elsewhere) and looked at the set of actual sim OEI tracks following failure. Some of the folk didn't track all that well. Hence my concern being more with how to make the tracking requirements easy for the pilot in anger ...
The way you guys do this stuff; I don't believe is written down in any publication
The requirements are specified (eg NFP has to be ...). The way that the regs are implemented is fairly common with the main difference being how much money an operator is prepared to throw at getting the last kilo out of the analysis.. and that, naturally, is a cost/benefit exercise.
There is no point spending a fortune getting a gold plated escape if the cheapie back of a fag packet version gave you similar RTOW data. For those of us who play with this stuff, a difficult aerodrome can cause us head scratching for several days while we play with this or that (or half a dozen more) different escape tracks ... places like Canberra and Gladstone in Oz fit this class of aerodromes ..
but I would not mind some assistance in aquiring the 'Boeing engineers Book'
Boeing Performance Engineer Training Manual (Doc D6-1420). Provided to students on the Boeing course and usually found in Mech/Aero Eng uni libraries. Excellent undergrad level text.
and so my Company would have me follow the standard MAP and accelerate at 1000agl
I can only observe that a reputable operator will have reviewed the runways and run OEI missed approach analyses similar to the takeoff analyses to get the aircraft up and away from the bumpy bits. Nothing new to this - Ansett and TAA (and, presumably, Qantas) were doing just this in the 60s for critical runways .. and spending considerable effort on the work. I think I still have a copy of one of John Walshe's studies on file somewhere ...
A big concern relates to the distance required to reconfigure to the missed approach configuration and commence the climb ...
would it be fair to say that the aerodrome operators should be required to be able to supply, quickly, the required detailed surveys that are necessary to generate the procedures?
I suggest not. Depending on the jurisdiction, the owners will provide that which is required (and this costs someone - ultimately the operators - dollars). At present, one might see one or more of Type A (or its diminutives), Type B, Type C (I can't ever recall having seen one of these) and several other sets of OLS data. Given the variety of performance needs for a variety of aircraft Types, unless the surroundings are simple (eg a ridge or big hill and not much more) it would become a tad messy ... Probably better for the operator (or operators in conjunction/service providers) to do the work and contain the costs to the end users.
The Oz aerodrome MOS is a useful reference document for those who fancy a little light bedtime reading ..
It seems that a lot of this survey detail is just not readily available
For most places, the problems are relatively easy to determine and address. Certainly, one needs to have cultivated a range of suitable contacts for obstacle data and, on occasion, one needs to throw the theodolite over the shoulder and go forth into the hinterland .. at the end of the day it is just a matter of the will to do the work .. and this comes down to corporate risk assessment for the operator.
Do your airlines share their E/O SIDS and procedures with the local ATC's?
I believe that most don't. Some of us will make sure that any unusual escapes are notified to ATC or equivalent. Clearly, if the procedure is compatible with "normal" traffic handling, the need is somewhat less.
the meaning of paras 12.1B and 12.4 is that the planning must go to either MSA if there is no navaid or the enroute OCA (1360'?) in the safety height containment area where there is a navaid.
Oz CAO 20.7.1b has always been an interesting animal. It is similar to the US 23/25-91/121 type of approach where there is a separation of airworthiness and operational standards. In the case of the Australian vehicles (historically) a few gremlins sneaked through the process with the result that we have had some discrepancies over the years.
For the younger folk who don't recall the "old" ANOs etc., the airworthiness bits were in ANO 101.5 and 6 for the heavies with the operational data in ANO 20.7.1B. 101.5/6 largely called up the relevant UK/US standards .. if we go back further to the times of ANOs which had more subordinate identifying numbers than you could poke a stick at, we would find detailed standards. These later became CAOs and, in line with the harmonisation processes, the Australian airworthiness vehicles were dumped without ceremony in the WPB ... This process has had both its good and bad points for the local Industry.
Functionally, how one implements the requirement depends on how much work you want to throw at the problem. In most cases use of declared data, such as MSA saves some time and effort.
I also understand that AIP is only a place to publish
A question for the legal folk to offer comment ...
However, it has always been understood generally that a requirement is mandated via the Act, Regs and Orders with notes and AIP providing expanded information. However, the potential risk is that, if one were to depart from an AIP "requirement", then one would need to be very certain that the requirement wasn't glued to a Reg, etc. The easier process is to adopt the AIP as mandatory .. unless the context clearly indicates an option. Just my opinion.
I was far from convinced that would keep us clear of obstacles! Surely we would have been better off requesting a SID which at least went it the same overall direction as the SE procedure?
Presuming that the operator has done the sums, then the matter should be prescribed in SOP. If SOP is a bit rubbery, then one should enquire of the operator's management what the rubbery bits really mean. At the end of the day one can always decline the SID if the concern is considered significant and reasonable.
I've observed even average pilots tend to fly closer to the "Test Pilot's" Gross gradient than the Net.
I've no problem with that observation. However, and this goes back to earlier steam driven aircraft, the then DCA's Ian C did a study (TAA, as I recall - I have no doubt that the results would have been similar elsewhere) and looked at the set of actual sim OEI tracks following failure. Some of the folk didn't track all that well. Hence my concern being more with how to make the tracking requirements easy for the pilot in anger ...
The way you guys do this stuff; I don't believe is written down in any publication
The requirements are specified (eg NFP has to be ...). The way that the regs are implemented is fairly common with the main difference being how much money an operator is prepared to throw at getting the last kilo out of the analysis.. and that, naturally, is a cost/benefit exercise.
There is no point spending a fortune getting a gold plated escape if the cheapie back of a fag packet version gave you similar RTOW data. For those of us who play with this stuff, a difficult aerodrome can cause us head scratching for several days while we play with this or that (or half a dozen more) different escape tracks ... places like Canberra and Gladstone in Oz fit this class of aerodromes ..
but I would not mind some assistance in aquiring the 'Boeing engineers Book'
Boeing Performance Engineer Training Manual (Doc D6-1420). Provided to students on the Boeing course and usually found in Mech/Aero Eng uni libraries. Excellent undergrad level text.
and so my Company would have me follow the standard MAP and accelerate at 1000agl
I can only observe that a reputable operator will have reviewed the runways and run OEI missed approach analyses similar to the takeoff analyses to get the aircraft up and away from the bumpy bits. Nothing new to this - Ansett and TAA (and, presumably, Qantas) were doing just this in the 60s for critical runways .. and spending considerable effort on the work. I think I still have a copy of one of John Walshe's studies on file somewhere ...
A big concern relates to the distance required to reconfigure to the missed approach configuration and commence the climb ...
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mcdhu,
Only 3 runway changes in 20 minutes? You must know someone there! I was under the impression that they changed the runway direction every 5 minutes to spread the wear, the Swiss are very economical people.
To address your question - Most operators do NOT establish OEI missed approach procedures, they should
As J_T says, the Australian operators did take this seriously, and I'm a product of that system.
A few points about PANS-OPS missed Approach procedures -
(1) They provide for a 2.5% Obstacle-Clear Gradient with 100 feet clearance of obstacles during the missed approach. This gradient may be higher if required, e.g. Hong Kong,
(2) A 2 engined aircraft at it's Approach Climb Limit is only required to achieve 2.1% climb gradient....... Oh dear!
There's no legislative requirement, as there is for Takeoff, for the Missed Approach with One Engine Inoperative.
There's several ways to address the problem.
First, limit your landing weight to one which will meet a 2.5% (or greater) climb gradient during missed approach (I believe that the JAA is addressing this, but am unsure if they have done so yet). In the Ops Manuals that I prepare, I throw the AFM Approach Climb data into the WPB, and re-issue "new" data for 2.5% with adjustments for those occasions when the required gradient may be higher. This should not be too difficult for the pilot to do, Approach Climb Flap is usually one of the approved Takeoff Flap settings, and data is available.
The biggest problem is the Acceleration Altitude, these are often-times very high (for ATC purposes), and you have no way of knowing if these are created for ATC or Obstacle Clearance purposes. If you want to go all the way to Missed Approach Altitude, you'll probably "bust" the 5 or 10 minute Takeoff Thrust limit. If TRULY caught out, I couldn't give a damn, these limits are created for engine life expectancy, thousands of hours down the track, and I'm far more interested in MY life expectancy.
The best of all proposals carries a SEVERE caveat. The SUGGESTION about to be made ONLY applies only to aircraft with very accurate LNAV systems, preferrably GPS/IRS. Most DEFINATELY the suggestion applies to aircraft with a DIRECT means of flying Track, NOT Heading. Here it is -
Fly the OEISID for the runway, simple, but ensure accurate Tracking of the highest order. The Takeoff splays for the OEISID on Takeoff commence at the Departure end of the Runway, the missed approach begins before the Approach end of the runway. The tolerance for straying off the RWY centre-line until passing the Departure end of the Runway (DER) is ZERO!!!! Any straying outside Runway direction puts you immediately into the mine-field of No Man's Land! One big plus, is that you are commencing the procedure already several hundred feet above the runway, as opposed to from the runway.
A good example of reverting to the OEISID for a missed approach is Hong Kong RWYs 25L and 25R. Both missed approaches make a Right turn, and take the aircraft over the most horrendouus course of obstacles, whilst the OEISID (intended for Takeoff) makes a Left turn after a suitable distance to a Southerly heading over water. You could maintain this Southerly Track all the way to the Philippines in complete comfort. In this same case, any straying off RWY centre-line (to the Left) would almost guarantee terrain impact.
Pugilistic Animus,
Expect that looooong overdue E-mail. You've certainly given me a lot more to talk about than before!
"The way you guys do this stuff; I don't believe is written down in any publication".
The mode de emploi is not written anywhere, the requirements ARE and at least CASA Australia do provide good guidance material. There's 100 ways to "skin a cat", so long as we all end up with suitably skinned cats is the bottom line (where did that stupid expression come from?)
John_T,
Thanks for the link to the light reading. Being an insomnia sufferer, that contribution is a welcome addition to my E-Library. Thanks John!
I do agree with Mr. C's observations WRT average line pilot's ability to achieve "better than Net" climb performance, and agree with his concerns about lateral tracking capability. (It must have been Ansett pilots that IC was watching, TAA pilots would never do that)Hmmm, the latter did apply in an earlier era, but in the modern day with good Track flying data capability, extended RWY centre-lines on the Map display etc., it can one day be shelved with other tomes relating to weird raw data 'happenings'. This is particularly so in our training where the trainees are hammered, "Don't just correct the swing and initial tracking error, get back on the bleedin' track!".
I'll be sorry when this thread fizzles out, I'm having fun!
I deleted Ian's surname just in case he might not want to be identified .. it probably would be crass of me to ring him to enquire .. JT
Only 3 runway changes in 20 minutes? You must know someone there! I was under the impression that they changed the runway direction every 5 minutes to spread the wear, the Swiss are very economical people.
To address your question - Most operators do NOT establish OEI missed approach procedures, they should
As J_T says, the Australian operators did take this seriously, and I'm a product of that system.A few points about PANS-OPS missed Approach procedures -
(1) They provide for a 2.5% Obstacle-Clear Gradient with 100 feet clearance of obstacles during the missed approach. This gradient may be higher if required, e.g. Hong Kong,
(2) A 2 engined aircraft at it's Approach Climb Limit is only required to achieve 2.1% climb gradient....... Oh dear!
There's no legislative requirement, as there is for Takeoff, for the Missed Approach with One Engine Inoperative.
There's several ways to address the problem.
First, limit your landing weight to one which will meet a 2.5% (or greater) climb gradient during missed approach (I believe that the JAA is addressing this, but am unsure if they have done so yet). In the Ops Manuals that I prepare, I throw the AFM Approach Climb data into the WPB, and re-issue "new" data for 2.5% with adjustments for those occasions when the required gradient may be higher. This should not be too difficult for the pilot to do, Approach Climb Flap is usually one of the approved Takeoff Flap settings, and data is available.
The biggest problem is the Acceleration Altitude, these are often-times very high (for ATC purposes), and you have no way of knowing if these are created for ATC or Obstacle Clearance purposes. If you want to go all the way to Missed Approach Altitude, you'll probably "bust" the 5 or 10 minute Takeoff Thrust limit. If TRULY caught out, I couldn't give a damn, these limits are created for engine life expectancy, thousands of hours down the track, and I'm far more interested in MY life expectancy.
The best of all proposals carries a SEVERE caveat. The SUGGESTION about to be made ONLY applies only to aircraft with very accurate LNAV systems, preferrably GPS/IRS. Most DEFINATELY the suggestion applies to aircraft with a DIRECT means of flying Track, NOT Heading. Here it is -
Fly the OEISID for the runway, simple, but ensure accurate Tracking of the highest order. The Takeoff splays for the OEISID on Takeoff commence at the Departure end of the Runway, the missed approach begins before the Approach end of the runway. The tolerance for straying off the RWY centre-line until passing the Departure end of the Runway (DER) is ZERO!!!! Any straying outside Runway direction puts you immediately into the mine-field of No Man's Land! One big plus, is that you are commencing the procedure already several hundred feet above the runway, as opposed to from the runway.
A good example of reverting to the OEISID for a missed approach is Hong Kong RWYs 25L and 25R. Both missed approaches make a Right turn, and take the aircraft over the most horrendouus course of obstacles, whilst the OEISID (intended for Takeoff) makes a Left turn after a suitable distance to a Southerly heading over water. You could maintain this Southerly Track all the way to the Philippines in complete comfort. In this same case, any straying off RWY centre-line (to the Left) would almost guarantee terrain impact.
Pugilistic Animus,
Expect that looooong overdue E-mail. You've certainly given me a lot more to talk about than before!
"The way you guys do this stuff; I don't believe is written down in any publication".
The mode de emploi is not written anywhere, the requirements ARE and at least CASA Australia do provide good guidance material. There's 100 ways to "skin a cat", so long as we all end up with suitably skinned cats is the bottom line (where did that stupid expression come from?)
John_T,
Thanks for the link to the light reading. Being an insomnia sufferer, that contribution is a welcome addition to my E-Library. Thanks John!
I do agree with Mr. C's observations WRT average line pilot's ability to achieve "better than Net" climb performance, and agree with his concerns about lateral tracking capability. (It must have been Ansett pilots that IC was watching, TAA pilots would never do that
)Hmmm, the latter did apply in an earlier era, but in the modern day with good Track flying data capability, extended RWY centre-lines on the Map display etc., it can one day be shelved with other tomes relating to weird raw data 'happenings'. This is particularly so in our training where the trainees are hammered, "Don't just correct the swing and initial tracking error, get back on the bleedin' track!".I'll be sorry when this thread fizzles out, I'm having fun!
I deleted Ian's surname just in case he might not want to be identified .. it probably would be crass of me to ring him to enquire .. JT
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the Australian operators did take this seriously, and I'm a product of that system.
As am I ... which is why, I guess, we speak similar concerns and priorities.
There's no legislative requirement, as there is for Takeoff, for the Missed Approach with One Engine Inoperative.
.. but he who ignores it for critical runways may make page 3 (or page 1) of the newspapers .. depending on the number of folk killed in the ensuing CFIT
If TRULY caught out, I couldn't give a damn, these limits are created for engine life expectancy
A pertinent post from barit1 earlier today on this very topic (post #13 in the TOGA thread)
Any straying outside Runway direction puts you immediately into the mine-field of No Man's Land!
One of the reasons we push these sort of threads is the general lack of understanding about just how tight the initial splay tracking tolerances are ..
but in the modern day with good Track flying data capability, extended RWY centre-lines on the Map display etc., it can one day be shelved
.. but, as you and I both know from sitting in back at the organ player's station ... one has to provide plenty of practice to get the message across. Hence my game of getting initial commands (in particular) to the stage where they could handle a min speed, aft CG seizure (or similar .. the blue crane bird strike programmed into the 732 in a land far away was very illustrative on this point) during the rotation flare ... with a requirement to backtrack the other end localiser .. it was always a buzz, when the pilot got to a comfortable standard, .. to say something along the lines of "oh well .. that's as hard as it gets ... guess you deserve a coffee" and watch the individual waltz out of the sim with a head twice the diameter of the shoulder width ..
The 733/4 aren't in the league of 777s and the like .. but, even then, with track up etc., it took some practice exposure for folk to get on top of the pushing and pulling needed to handle a critical takeoff failure.
Mind you .. "routine" failures thereafter rarely raised more than a bored yawn from the front seat.
As am I ... which is why, I guess, we speak similar concerns and priorities.
There's no legislative requirement, as there is for Takeoff, for the Missed Approach with One Engine Inoperative.
.. but he who ignores it for critical runways may make page 3 (or page 1) of the newspapers .. depending on the number of folk killed in the ensuing CFIT
If TRULY caught out, I couldn't give a damn, these limits are created for engine life expectancy
A pertinent post from barit1 earlier today on this very topic (post #13 in the TOGA thread)
Any straying outside Runway direction puts you immediately into the mine-field of No Man's Land!
One of the reasons we push these sort of threads is the general lack of understanding about just how tight the initial splay tracking tolerances are ..
but in the modern day with good Track flying data capability, extended RWY centre-lines on the Map display etc., it can one day be shelved
.. but, as you and I both know from sitting in back at the organ player's station ... one has to provide plenty of practice to get the message across. Hence my game of getting initial commands (in particular) to the stage where they could handle a min speed, aft CG seizure (or similar .. the blue crane bird strike programmed into the 732 in a land far away was very illustrative on this point) during the rotation flare ... with a requirement to backtrack the other end localiser .. it was always a buzz, when the pilot got to a comfortable standard, .. to say something along the lines of "oh well .. that's as hard as it gets ... guess you deserve a coffee" and watch the individual waltz out of the sim with a head twice the diameter of the shoulder width ..
The 733/4 aren't in the league of 777s and the like .. but, even then, with track up etc., it took some practice exposure for folk to get on top of the pushing and pulling needed to handle a critical takeoff failure.
Mind you .. "routine" failures thereafter rarely raised more than a bored yawn from the front seat.
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Thank you, Old Smokey. Please can I now explore further the App/Climb Gradient with you; my queries may seem simplistic to you guys, but it seems to me that the level of knowledge out there generally leaves quite a lot to be desired!
First, the SID is built around 2.5%, but I guess that is an instantaneous figure achievable as we establish the climb at the appropriate speed and config which, it is assumed by the designer of the procedure, that we will maintain as we climb towards the Accn Alt. My question is can we expect to maintain that gradient, or will it degrade as we climb through an increment of, say, 2000'?
Next, for those of us who have a Company imposed Accn Alt below the MAP, does the 2.5% mean all the way to the MAP including the level accn or is there some (fudge) factor built in for this.
Sorry if this seems rushed and poorly explained, but am being pressurised to make way for MSN. Night all!!
mcdhu
First, the SID is built around 2.5%, but I guess that is an instantaneous figure achievable as we establish the climb at the appropriate speed and config which, it is assumed by the designer of the procedure, that we will maintain as we climb towards the Accn Alt. My question is can we expect to maintain that gradient, or will it degrade as we climb through an increment of, say, 2000'?
Next, for those of us who have a Company imposed Accn Alt below the MAP, does the 2.5% mean all the way to the MAP including the level accn or is there some (fudge) factor built in for this.
Sorry if this seems rushed and poorly explained, but am being pressurised to make way for MSN. Night all!!
mcdhu
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mcdhu,
I'm by no means a PANS-OPS or TERPS "expert", I do have a good working knowledge of it because of it's relationship to other Performance areas where I am required to know a bit more.
I have put it to my employer and other clients that we should take this matter just as seriously as the Takeoff case, and fully "engineer" it. The inevitable reply is "Is it a LEGAL requirement ?" That usually ends the conversation.
If there is any commonality between FAR 25 (and equivalents) and PANS-OPS(and equivalents), and there isn't, but similar principals MAY be involved.
FAR 25 does not require the user to account for the performance degradation during the climb in 2nd segment. (I do, at the mid-point between end of 1st Segment and MAA, but that's me). The airfield elevation applies, thus, you may consider it as an INITIAL 2.5%, degrading thereafter. (Wonderful isn't it?). Even conservative Australia does not require application of QNH, which may well 'bump up' the prevailing Pressure Height by 1,000 ft or so. (Boeing DO, and so do I).
To address the second part of your question, unless an Acceleration Altitude is specified, you are required to maintain the 2.5% Gradient all the way to Missed Approach Altitude. Not having a "deep" knowledge of PANS-OPS, I don't know how long the Acceleration Segment is (if quoted), but bear in mind that OEI, this may be veeery long, anything up to 30,000 M. I doubt that this is built into the Missed Approach procedures, but I stand by to be corrected.
Pretty vague answers I'm afraid mcdhu, but guidance for your further reaearch. All will become clear when Oz_Expat emerges from his cave.
J_T, "I deleted Ian's surname just in case he might not want to be identified .. it probably would be crass of me to ring him to enquire .. JT". Sorry for breaking one of the cardinal rules, actually Prooners, the "C" stands for Claus, Santa Claus that is, to whom the gentleman referred to has acquired a remarkable resemblance.
Thanks for the cross reference to Barit1's post, nice to see that we speak the same language.
Oz_Expat, where are you when we need you?
Regards,
Old Smokey
I'm by no means a PANS-OPS or TERPS "expert", I do have a good working knowledge of it because of it's relationship to other Performance areas where I am required to know a bit more.
I have put it to my employer and other clients that we should take this matter just as seriously as the Takeoff case, and fully "engineer" it. The inevitable reply is "Is it a LEGAL requirement ?" That usually ends the conversation.
If there is any commonality between FAR 25 (and equivalents) and PANS-OPS(and equivalents), and there isn't, but similar principals MAY be involved.
FAR 25 does not require the user to account for the performance degradation during the climb in 2nd segment. (I do, at the mid-point between end of 1st Segment and MAA, but that's me). The airfield elevation applies, thus, you may consider it as an INITIAL 2.5%, degrading thereafter. (Wonderful isn't it?). Even conservative Australia does not require application of QNH, which may well 'bump up' the prevailing Pressure Height by 1,000 ft or so. (Boeing DO
, and so do I).To address the second part of your question, unless an Acceleration Altitude is specified, you are required to maintain the 2.5% Gradient all the way to Missed Approach Altitude. Not having a "deep" knowledge of PANS-OPS, I don't know how long the Acceleration Segment is (if quoted), but bear in mind that OEI, this may be veeery long, anything up to 30,000 M. I doubt that this is built into the Missed Approach procedures, but I stand by to be corrected.
Pretty vague answers I'm afraid mcdhu, but guidance for your further reaearch. All will become clear when Oz_Expat emerges from his cave.
J_T, "I deleted Ian's surname just in case he might not want to be identified .. it probably would be crass of me to ring him to enquire .. JT". Sorry for breaking one of the cardinal rules, actually Prooners, the "C" stands for Claus, Santa Claus that is, to whom the gentleman referred to has acquired a remarkable resemblance.
Thanks for the cross reference to Barit1's post, nice to see that we speak the same language.
Oz_Expat, where are you when we need you?
Regards,
Old Smokey
