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ArcticFlyer wrote:As I understand it the 737 (with 2 A/Ps) is a fail passive system whereas the 747, 757 and 767 (with 3 A/Ps) are fail operational systems with respect to autoland capability. It has nothing to do with the size of the airplane.
The 747/757/767 can also autoland with one engine inoperative while the 737 cannot.
BoeingGuy wrote:There was an old option on the 767 to be able to do a CAT 3A Autoland with an engine out. I assume the 757 had the same option. Baseline on the 757/767 was to not be able to Autoland with an engine out.
rt23456p wrote:The Boeing 737 NG is a relatively smaller, narrow-body aircraft primarily used for short-to-medium-haul flights. It is equipped with two autopilot systems, labeled A and B, which can be engaged independently or simultaneously. Having two autopilot systems provides redundancy and allows for improved performance during certain flight phases, such as an autoland procedure.
On the other hand, the Boeing 747 is a larger, wide-body aircraft designed for long-haul flights. The 747 has more complex systems and a greater need for redundancy, which is why it has three autopilot systems, labeled A, B, and C. The triple-redundant autopilot system in the 747 can provide additional safety and performance benefits during critical flight phases, such as takeoff, cruise, and landing. This is especially important for long-haul flights where the aircraft operates at higher altitudes and over remote areas with limited navigation aids.
BoeingGuy wrote:ArcticFlyer wrote:As I understand it the 737 (with 2 A/Ps) is a fail passive system whereas the 747, 757 and 767 (with 3 A/Ps) are fail operational systems with respect to autoland capability. It has nothing to do with the size of the airplane.
The 747/757/767 can also autoland with one engine inoperative while the 737 cannot.
Neither paragraph is totally true. The 737 has optional Fail-Operational capability with the two Autopilot channels. It’s in the option catalog. However, baseline on the 737 is Fail-Passive as you indicate.
There was an old option on the 767 to be able to do a CAT 3A Autoland with an engine out. I assume the 757 had the same option. Baseline on the 757/767 was to not be able to Autoland with an engine out.
AirKevin wrote:rt23456p wrote:The Boeing 737 NG is a relatively smaller, narrow-body aircraft primarily used for short-to-medium-haul flights. It is equipped with two autopilot systems, labeled A and B, which can be engaged independently or simultaneously. Having two autopilot systems provides redundancy and allows for improved performance during certain flight phases, such as an autoland procedure.
On the other hand, the Boeing 747 is a larger, wide-body aircraft designed for long-haul flights. The 747 has more complex systems and a greater need for redundancy, which is why it has three autopilot systems, labeled A, B, and C. The triple-redundant autopilot system in the 747 can provide additional safety and performance benefits during critical flight phases, such as takeoff, cruise, and landing. This is especially important for long-haul flights where the aircraft operates at higher altitudes and over remote areas with limited navigation aids.
I feel like the credibility of the source got shot down as soon as the above was pointed out. For starters, the CMD switches on the MCP aren't marked A, B, and C, but rather L, C, and R. Additionally, a 747 operating a long-haul flight isn't going to be flying at a higher altitude than a 737 since it would be far too heavy to do so during the initial stage of the flight. Even near the end of the flight, the 747 might not be flying any higher than a 737.
AirKevin wrote:rt23456p wrote:The Boeing 737 NG is a relatively smaller, narrow-body aircraft primarily used for short-to-medium-haul flights. It is equipped with two autopilot systems, labeled A and B, which can be engaged independently or simultaneously. Having two autopilot systems provides redundancy and allows for improved performance during certain flight phases, such as an autoland procedure.
On the other hand, the Boeing 747 is a larger, wide-body aircraft designed for long-haul flights. The 747 has more complex systems and a greater need for redundancy, which is why it has three autopilot systems, labeled A, B, and C. The triple-redundant autopilot system in the 747 can provide additional safety and performance benefits during critical flight phases, such as takeoff, cruise, and landing. This is especially important for long-haul flights where the aircraft operates at higher altitudes and over remote areas with limited navigation aids.
I feel like the credibility of the source got shot down as soon as the above was pointed out. For starters, the CMD switches on the MCP aren't marked A, B, and C, but rather L, C, and R. Additionally, a 747 operating a long-haul flight isn't going to be flying at a higher altitude than a 737 since it would be far too heavy to do so during the initial stage of the flight. Even near the end of the flight, the 747 might not be flying any higher than a 737.
TangoandCash wrote:BoeingGuy wrote:There was an old option on the 767 to be able to do a CAT 3A Autoland with an engine out. I assume the 757 had the same option. Baseline on the 757/767 was to not be able to Autoland with an engine out.
Curious on the engine out autoland option. Was there additional equipment necessary or was this a paperwork/certification thing?
Tristarsteve wrote:
I hate these topics because they show how much knowledge you have forgotten!!
Tristarsteve wrote:TangoandCash wrote:BoeingGuy wrote:There was an old option on the 767 to be able to do a CAT 3A Autoland with an engine out. I assume the 757 had the same option. Baseline on the 757/767 was to not be able to Autoland with an engine out.
Curious on the engine out autoland option. Was there additional equipment necessary or was this a paperwork/certification thing?
I hate these topics because they show how much knowledge you have forgotten!!
There must have been a different electrical switching system for engine out autoland.
On B757 and 767 the L and R A/P were fed from the L and R engine generators. For Cat 3 landing the C A/P was also engaged, and this was fed from the standby electrical system fed by the hydraulic motor generator. You needed three A/P and three electrical supplies for Cat 3B landing. (Our aircraft had Cat3B, perhaps this was different from Cat 3A)
p.s. you only need 3 A/P for Cat 3 Autoland.
rt23456p wrote:Just curious as well, about a three CMD based plane, can 2 of those CMD be MEL?
rt23456p wrote:Tristarsteve wrote:TangoandCash wrote:
Curious on the engine out autoland option. Was there additional equipment necessary or was this a paperwork/certification thing?
I hate these topics because they show how much knowledge you have forgotten!!
There must have been a different electrical switching system for engine out autoland.
On B757 and 767 the L and R A/P were fed from the L and R engine generators. For Cat 3 landing the C A/P was also engaged, and this was fed from the standby electrical system fed by the hydraulic motor generator. You needed three A/P and three electrical supplies for Cat 3B landing. (Our aircraft had Cat3B, perhaps this was different from Cat 3A)
p.s. you only need 3 A/P for Cat 3 Autoland.
What are the ILS Cat for a Land 2 autoland?
Tristarsteve wrote:TangoandCash wrote:BoeingGuy wrote:There was an old option on the 767 to be able to do a CAT 3A Autoland with an engine out. I assume the 757 had the same option. Baseline on the 757/767 was to not be able to Autoland with an engine out.
Curious on the engine out autoland option. Was there additional equipment necessary or was this a paperwork/certification thing?
I hate these topics because they show how much knowledge you have forgotten!!
There must have been a different electrical switching system for engine out autoland.
On B757 and 767 the L and R A/P were fed from the L and R engine generators. For Cat 3 landing the C A/P was also engaged, and this was fed from the standby electrical system fed by the hydraulic motor generator. You needed three A/P and three electrical supplies for Cat 3B landing. (Our aircraft had Cat3B, perhaps this was different from Cat 3A)
p.s. you only need 3 A/P for Cat 3 Autoland.
ArcticFlyer wrote:rt23456p wrote:Just curious as well, about a three CMD based plane, can 2 of those CMD be MEL?
On most airplanes all autopilots can be MEL'd although there are increasing operational restrictions depending on how many don't work. On the 737 (which only has 2), if one is MEL'd the only limitation is that you can't autoland. If they're both out you lose RVSM and ETOPS.
On the 767 (3 A/Ps), if one is MEL'd you don't really lose anything (there might be a CATIII issue but my company doesn't have that anyway so I don't know), two out and you lose autoland and if all are out you lose RVSM and ETOPS.
N1120A wrote:I believe many airlines have policies that allow a crew to refuse an airplane with all A/P's inop, though most allow for dispatch without a working autopilot if it works out operationally.
ArcticFlyer wrote:N1120A wrote:I believe many airlines have policies that allow a crew to refuse an airplane with all A/P's inop, though most allow for dispatch without a working autopilot if it works out operationally.
At my company we are explicitly allowed to refuse an aircraft with any MEL item, and our CBA specifically restricts us to 4 hours block time per duty period with all A/Ps inop.
ArcticFlyer wrote:N1120A wrote:I believe many airlines have policies that allow a crew to refuse an airplane with all A/P's inop, though most allow for dispatch without a working autopilot if it works out operationally.
At my company we are explicitly allowed to refuse an aircraft with any MEL item, and our CBA specifically restricts us to 4 hours block time per duty period with all A/Ps inop.
BoeingGuy wrote:ArcticFlyer wrote:N1120A wrote:I believe many airlines have policies that allow a crew to refuse an airplane with all A/P's inop, though most allow for dispatch without a working autopilot if it works out operationally.
At my company we are explicitly allowed to refuse an aircraft with any MEL item, and our CBA specifically restricts us to 4 hours block time per duty period with all A/Ps inop.
You aren’t RVSM capable without an Autopilot also, to my understanding.
ArcticFlyer wrote:N1120A wrote:I believe many airlines have policies that allow a crew to refuse an airplane with all A/P's inop, though most allow for dispatch without a working autopilot if it works out operationally.
At my company we are explicitly allowed to refuse an aircraft with any MEL item, and our CBA specifically restricts us to 4 hours block time per duty period with all A/Ps inop.
rt23456p wrote:ArcticFlyer wrote:N1120A wrote:I believe many airlines have policies that allow a crew to refuse an airplane with all A/P's inop, though most allow for dispatch without a working autopilot if it works out operationally.
At my company we are explicitly allowed to refuse an aircraft with any MEL item, and our CBA specifically restricts us to 4 hours block time per duty period with all A/Ps inop.
Just curious, does a toilet been inop considered MEL?
rt23456p wrote:Just curious, does a toilet been inop considered MEL?
ArcticFlyer wrote:rt23456p wrote:Just curious, does a toilet been inop considered MEL?
Regulations require that, in order to dispatch with any installed piece of equipment inoperative, the inoperative equipment must be listed in the MEL which is simply a manual that details which pieces of equipment can be inop, how long they can be inop before they need to be fixed and any operating restrictions associated with that equipment being inop. This includes things like lavs, passenger seats, ovens and other equipment that doesn't directly relate to flying the aircraft.
ArcticFlyer wrote:rt23456p wrote:Just curious, does a toilet been inop considered MEL?
Regulations require that, in order to dispatch with any installed piece of equipment inoperative, the inoperative equipment must be listed in the MEL which is simply a manual that details which pieces of equipment can be inop, how long they can be inop before they need to be fixed and any operating restrictions associated with that equipment being inop. This includes things like lavs, passenger seats, ovens and other equipment that doesn't directly relate to flying the aircraft.
Starlionblue wrote:ArcticFlyer wrote:rt23456p wrote:Just curious, does a toilet been inop considered MEL?
Regulations require that, in order to dispatch with any installed piece of equipment inoperative, the inoperative equipment must be listed in the MEL which is simply a manual that details which pieces of equipment can be inop, how long they can be inop before they need to be fixed and any operating restrictions associated with that equipment being inop. This includes things like lavs, passenger seats, ovens and other equipment that doesn't directly relate to flying the aircraft.
The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
N1120A wrote:Starlionblue wrote:ArcticFlyer wrote:Regulations require that, in order to dispatch with any installed piece of equipment inoperative, the inoperative equipment must be listed in the MEL which is simply a manual that details which pieces of equipment can be inop, how long they can be inop before they need to be fixed and any operating restrictions associated with that equipment being inop. This includes things like lavs, passenger seats, ovens and other equipment that doesn't directly relate to flying the aircraft.
The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
I bet they made the cup holders a go/no go item after the engine rollback thing on the A350!
Starlionblue wrote:N1120A wrote:Starlionblue wrote:
The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
I bet they made the cup holders a go/no go item after the engine rollback thing on the A350!
Three cup holders on each side and still they managed to spill on the centre console.
Jokes aside, accidents happen, and the console is now thankfully spillproof. The lids on our cups have not gone away, mind you.
Starlionblue wrote:The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
ArcticFlyer wrote:Starlionblue wrote:The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
As an interesting sidenote when I was flying the Dash 8 the coffee maker was not deferable. Not sure if that was merely an oversight on De Havilland's part or if there was actually a good reason for it but we all kind of chuckled at that one, especially given the fact that other "minor" systems like nosewheel steering were competely deferable.
ArcticFlyer wrote:Starlionblue wrote:The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
As an interesting sidenote when I was flying the Dash 8 the coffee maker was not deferable. Not sure if that was merely an oversight on De Havilland's part or if there was actually a good reason for it but we all kind of chuckled at that one, especially given the fact that other "minor" systems like nosewheel steering were competely deferable.
rt23456p wrote:ArcticFlyer wrote:Starlionblue wrote:The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
As an interesting sidenote when I was flying the Dash 8 the coffee maker was not deferable. Not sure if that was merely an oversight on De Havilland's part or if there was actually a good reason for it but we all kind of chuckled at that one, especially given the fact that other "minor" systems like nosewheel steering were competely deferable.
Just curious, how on earth the aircraft will turn with the nosewheel not steering?
rt23456p wrote:ArcticFlyer wrote:Starlionblue wrote:The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
As an interesting sidenote when I was flying the Dash 8 the coffee maker was not deferable. Not sure if that was merely an oversight on De Havilland's part or if there was actually a good reason for it but we all kind of chuckled at that one, especially given the fact that other "minor" systems like nosewheel steering were competely deferable.
Just curious, how on earth the aircraft will turn with the nosewheel not steering?
rt23456p wrote:Just curious, how on earth the aircraft will turn with the nosewheel not steering?
rt23456p wrote:ArcticFlyer wrote:Starlionblue wrote:The sliding table and footrests on an A330 can be MELd for 120 days. It's horrific.
I jest. Maybe.
As an interesting sidenote when I was flying the Dash 8 the coffee maker was not deferable. Not sure if that was merely an oversight on De Havilland's part or if there was actually a good reason for it but we all kind of chuckled at that one, especially given the fact that other "minor" systems like nosewheel steering were competely deferable.
Just curious, how on earth the aircraft will turn with the nosewheel not steering?
N1120A wrote:rt23456p wrote:ArcticFlyer wrote:As an interesting sidenote when I was flying the Dash 8 the coffee maker was not deferable. Not sure if that was merely an oversight on De Havilland's part or if there was actually a good reason for it but we all kind of chuckled at that one, especially given the fact that other "minor" systems like nosewheel steering were competely deferable.
Just curious, how on earth the aircraft will turn with the nosewheel not steering?
It might not have steering from the tiller, but the pedal steering, which gives 6 degrees, might also be available. Differential braking, rudder authority and differential thrust can make the rest of the difference.
77west wrote:I would think pedal steering would also not be available if normal nosewheel steering was disabled, I believe they use the same HYD system. Could be mistaken though.
ArcticFlyer wrote:The 747/757/767 can also autoland with one engine inoperative while the 737 cannot.
Faro wrote:ArcticFlyer wrote:The 747/757/767 can also autoland with one engine inoperative while the 737 cannot.
I'm very curious as to what airlines' SOP say on this. You have an engine failure on approach/final approach, do you systematically take over manually from the autopilot? What's the risk of not doing so? Wouldn't you initiate a go-around just to check the status of the failed engine and ensure no fire, etc?
Faro
ArcticFlyer wrote:77west wrote:I would think pedal steering would also not be available if normal nosewheel steering was disabled, I believe they use the same HYD system. Could be mistaken though.
That is the case on the airplanes I have flown; if the nosewheel steering is inop then it's totally inop for both tiller and pedal inputs. It will still caster on its own with differential braking/thrust though.