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boeingflir

N1 Switch on Mode Control Panel

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I am having no success getting functionality from the N1 switch on the MCP. In particular, with a V1 engine failure I climb to my engine out acceleration altitude, I'm still in the takeoff mode i.e. with takeoff power. The profile is to bug the speed up to zero flap maneuver speed, select FLCH or VNAV after the flaps are retracted, then select continuous thrust (CON) for your climb by pressing the N1 switch supposedly. 

I have had no success programing the N1 switch on the MCP and I know what I'm doing there; I have all the throttle quadrant and yoke switches programed and they work fine on my CH products. NO matter what I do or what keyboard combo I choose that N1 switch is not functional. On top of that, if I try to engage the switch with my mouse cursor; no joy. The only way that I see to select continuous thrust is through the CDU on the N1 limit page.

If this is an NGX issue, i.e. a non functional switch, so be it. If I am making some kind of programing or procedural mistake…help!

As always I will appreciate your feedback.

Bruce Jacobs

PS

 

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I think your answer is in the FCOM, take a look at the description of the N1 switch on page 4.10.3. 

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Dan,

Thanks, Yes, I've seen that and it's the Boeing description of the switch function. Unfortunately it's well short of what I'm trying to figure out. 

It's going to take somebody to read this who is most likely not only a MSFS and NGX user, but also very well versed in 737NG procedures, like an airline pilot who uses the simulation to keep current and is actually operating the aircraft. I know that there are quite a few of you who really know how this thing works and what I'm talking about.

Cheers,

Bruce Jacobs

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I have had no success programing the N1 switch on the MCP and I know what I'm doing there; I have all the throttle quadrant and yoke switches programed and they work fine on my CH products. NO matter what I do or what keyboard combo I choose that N1 switch is not functional. On top of that, if I try to engage the switch with my mouse cursor; no joy. The only way that I see to select continuous thrust is through the CDU on the N1 limit page.

If this is an NGX issue, i.e. a non functional switch, so be it. If I am making some kind of programing or procedural mistake…help!

 

But you are asking why N1 isn't engaging when pressing the N1 switch on the MCP? So Dan told you to refer to the FCOM V2

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I don't have the FCOM open at the moment, but I recall that the N1 mode will do exactly as you described it doing in your problem description.That is, it controls thrust based on the thrust limit set in the CDU.

 

I suggested if you read the manual you'd realize it is working as the manual describes. Something it does better than I can.  If you are under the presumption that the N1 function is supposed to call up max continuous thrust then I think the FCOM explains that is not the function.

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I don't want to preach to the choir. There are probably a lot of real airline pilots on here. Some of this stuff can't be learned from the book or the printed profiles therein. That's why it takes 5 weeks to get a CFR121 type rating in on of these Jets.

Here's what I'm asking: We're taking off, at V1 we're committed to fly, we have an engine failure. VR, positive rate-gear up. The flight director should command V2-V2+20. At our E/O acc speed, generally 1000'agl for training purposes, we as for the MCP speed to be bugged up to 0 flap man speed. The aircraft pitches down to accelerate to that speed, we retract the flaps on schedule. At flaps up we probably have another couple of thousand feet to climb so we call for FLCH or VNAV. We are still at TO thrust which may have a time limit so we want to go to max continuous thrust. My impression was that is accomplished by pushing the N1 switch on the MCP. The only other way to do it is press the N1 button on the CDU which will open the N1 limit page on the FMC and you can select CON there. 

My problem is that I can not get functionality from the N1 switch on the MCP either by programing the switch to my CH controls through the NGX FMC and or FSUIPC.

I may have a misunderstanding, but the description of the N1 switch on page 4.10.3 does not answer my question unless I'm totally misunderstanding something.

2 issues, maybe, depending on the depth of my misunderstanding 1)Am I having a key press/programming problem? 2) How the hell does this interface actually work on the 737NG. BTW I have the actual Boeing FCOM and FCTM (flight crew training manual) as well as the PMDG manuals which I'm pleased to say are exact copies of Boeing procedures. Very nice.

OK, that's it. We'll see what comes up. I'll get on youtube and if all else fails I have a friend, far away who flies a BBJ.

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Simple

 

After the PM calls "FLAPS UP NO LIGHTS" the PF calls "LEVEL CHANGE, MCT" and engages the autopilot. The PM shall select LVL CHG and set MCT.

I don't use the NGX anymore i use prosim 737 as i have my own 737 built. I can test the N1 and see what happens.

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Good Vern, getting closer. How did the PM bring up the reference bug for MCT (annunciated CON above the N1 gauges)? As I said above  "My impression was that is accomplished by pushing the N1 switch on the MCP. The only other way to do it is press the N1 button on the CDU which will open the N1 limit page on the FMC and you can select CON there." 

Nice setup. I have a friend who has built a  prosim 747-400. Thanks.

Bruce Jacobs


You have to have a reference to set right? At TO the bug  is referencing whatever your take off thrust was. How do you get it to reference CON.

Bruce Jacobs

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No go into the FMC N1 page and select CONT and set the live engine thrust lever to the MCT bugs!

 

It does it automatically

 

With N1 you change the thrust setting from takeoff to climb and crz

 

Prosim 747? Prosim only does the 737 and now the new A320 suite

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OK, that's starting to make more sense. I understand that unlike the 777 the auto throttles have disengaged on an engine failure and you have to set it manually. I was confused where the CON reference comes from. The 777 knows that it has had an engine failure and when you go flaps up, FLCH, CON is automatically annunciated and the ATs automatically set CON.

I must have it wrong. This sim that he has, the 747-400, is quite a setup. Real Boeing seats (not 747, electric, but they are out of a 737) and I believe all of the components are made by a company in Canada). It's amazing with Boeing sim quality visual. No motion of course.

Bruce Jacobs

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If you are flying the 777 just know the differences ;)

 

Yeh its took me over a year to get it all installed and ordered etc! I have access to all Ryanair's manuals which goes a long way and helps me and my sim to be a more Boeing 737 environment following real procedures.

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Good work. The company that makes all the components for the 747 (FMC, MCP…everything) also makes the components to build a 737. I know that the cost is astronomical and the tweaking and labor seems endless for him, but it's something else when it's all working. It's "Life Size."

It sounds like you are doing it right. I'm certainly not telling you anything that you don't already know, the 737 is so much more labor intensive than the new Boeings. The 777 and 787 are "automatic." They are smart and really know what phase of flight that they are in and where they are on the approach. Boeing has done a good job on standardization with checklists and procedures though.

Thanks for your help :-)

PS

I've flown on RyanAir and Easy Jet. My daughter is in school in Edinburgh.

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I don't want to preach to the choir. There are probably a lot of real airline pilots on here. Some of this stuff can't be learned from the book or the printed profiles therein. That's why it takes 5 weeks to get a CFR121 type rating in on of these Jets.

Here's what I'm asking: We're taking off, at V1 we're committed to fly, we have an engine failure. VR, positive rate-gear up. The flight director should command V2-V2+20. At our E/O acc speed, generally 1000'agl for training purposes, we as for the MCP speed to be bugged up to 0 flap man speed. The aircraft pitches down to accelerate to that speed, we retract the flaps on schedule. At flaps up we probably have another couple of thousand feet to climb so we call for FLCH or VNAV. We are still at TO thrust which may have a time limit so we want to go to max continuous thrust. My impression was that is accomplished by pushing the N1 switch on the MCP. The only other way to do it is press the N1 button on the CDU which will open the N1 limit page on the FMC and you can select CON there. 

My problem is that I can not get functionality from the N1 switch on the MCP either by programing the switch to my CH controls through the NGX FMC and or FSUIPC.

I may have a misunderstanding, but the description of the N1 switch on page 4.10.3 does not answer my question unless I'm totally misunderstanding something.

2 issues, maybe, depending on the depth of my misunderstanding 1)Am I having a key press/programming problem? 2) How the hell does this interface actually work on the 737NG. BTW I have the actual Boeing FCOM and FCTM (flight crew training manual) as well as the PMDG manuals which I'm pleased to say are exact copies of Boeing procedures. Very nice.

OK, that's it. We'll see what comes up. I'll get on youtube and if all else fails I have a friend, far away who flies a BBJ.

Hi boeingflir and others. Long time lurker and user of PMDG aircraft for many years now, and I fly the 738 for a living. Thought I might be able to provide some insight into the above and some of the systems.

 

Firstly, the N1 button on the MCP is rarely used at most operators. Its only common use would be setting climb thrust during a non-VNAV takeoff. With current and recent FMC software VNAV takeoffs are the norm, and VNAV tells the A/T to set climb thrust at the specified thrust reduction altitude (all engines operating). This can be identified by the leftmost FMA changing from ARM to N1 (which is in effect VNAV pushing the N1 button for you).

 

About setting MCT with one engine inoperative - this is done manually after disconnecting the autothrottle. There are various techniques or flows to make sure this is all done - one such memory technique is ALMA, on reaching flaps-up maneuver speed, we go A/T out, LVL CHG, set MCT, A/P in. Some items may be done already, and they're not mandatory (e.g. we can happily stay in VNAV SPD instead of going to LVL CHG) and this isn't SOP, it's just one technique.

 

Also keep in mind it's rare for TO thrust to be at or above MCT - setting MCT on the good engine is generally a nice increase over our TO thrust. If you're doing a full thrust takeoff and it does happen to be above MCT, you've got a 10 minute limit, which is plenty of time to get sorted.

 

Hope this helps.

 

Mike Archer

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As previously mentioned, A/T should've been disconnected >400agl during Engine Severe Damage or Seperation NNM item execution. (QRH 8.2)

 

MCT (thrust mode annunciator = CON) is not set until after flaps are retracted and you're at or above flaps up maneuvering speed; by this time, the crew will have accomplished the Engine Severe Damage or Seperation NNC which means autothrottle is dead, which means N1 MCP no worky worky. (FCTM Flaps Up - One Engine Inoperative)

 

MCT is set in prep for climb to or above obstacle clearance height I.e LSALT/MSA, other height. MCT can only be set by via the CDU in normal circumstances, which is the usual trained circumstance. (FCTM Engine Inoperative Climb).

 

PS - as I was typing, Michael et al had already responded. Apologies for the regurgitation of material

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Thank you Brian and Mike. Just as I thought. I understand that it all happens through the FMC in terms of climb power, thrust reduction (or increase). That damn N1 switch was so confusing. The light bar illuminates when it's in N1 mode, but other than that it didn't seem to have much functionality. :-)

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All that N1 switch does is command the autothrottles to set power to the current N1 bug, be that takeoff power, climb, cruise, etc.

 

The likely reason it isn't doing anything when you press it is that the autothrottles will automatically disconnect about 30 seconds after an engine failure. So by the time you clean up and start thinking about adjusting thrust, the autothrottles are off. You can't command an autothrottle mode when they're turned off ;-)

 

The proper way to set max continuous thrust is just what you've been doing: select CON on the N1 page of the FMC, then adjust the throttle of the operating engine to the N1 bug.

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The N1 switch sounds a little bit like (but not quite the same as) the THR switch on the 747 -- very rarely used and not particularly well understood (I think the saying used to be something along the lines of -- "if you press that switch, the wings fall off"!)

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