PMDG 737-700 Tutorial: MCP - how does it work?

hello everyone and welcome to today's video i'm emanuel i'm a boeing 737 pilot and a member of pmdg's tech team in today's video we're going to talk about the mcp the mode control panel or the autopilot controls on the boeing 737ng there are two different types of mcps available the one you see right now is the collins mcp which is the newer version and there also is the older version the honeywell mcp which you can see right here you can choose which mcp you want to have installed on your aircraft from the aircraft options in the fmc so to find those go to menu pmdg setup aircraft equipment and then it's the first option for you so we have the honeywell slightly older and we have the collins which is the slightly newer one operationally both mcps do the same thing with one exception the collins the one you see right now is able to do fail operational autoland operations while the honeywell mcp is not able to do that apart from that they look slightly different but they work exactly the same so the mcp is basically split into four parts we have the left part here which is related to speed control so that includes the auto throttle arm switch the n1 and speed knobs flight level change and v-net and of course the speed intervent and the change over buttons as well as the speed selector over here the second part is related to lateral navigation that's this one over here it includes the heading select mode the lnf button the vor localizer button the approach button the heading dial and the angle of bank selector the third part is related to altitude control and it includes the altitudes knob the vertical speed knob altitude intervent vertical speed buttons and altitude hold buttons note that the v-not button can also be seen as part of the altitude functionality so imagine the vnav to counter this as well the last is the autopilot engagement section where you can choose between command a and b so autopilots a and b control wheel steering modes and the autopilot disengage bar so let's look into a little bit more detail as to what the exact buttons starting from the left hand side here the first we have is the course selector that one on the left hand side sets the course on the captain's navigation display and therefore the chords related to the number one radio while the right hand side sets it on the first office's display and the number two radio it works straight forward just like it would in any small airplane you might have flown before the next one here is the flight director switches you have one for each side and then you have this light above the flight directors so we are going to fly from the captaincy today so we are going to turn the left flight director on first and by doing that you see the green master light coming on and if we now turn on the second flight director you'll notice that the fd indication appears on the primary flight display but the master light stays on the side where it has been switched on first what this master mode is doing is basically deciding which radio is going to be used by the warlock and approach functions so we've got the master on the left hand side that means that the autopilot is going to use the left course and the number one radio for its operation you can switch this around for example if we turn the left one off now while the right one is still on the right is going to become the master and if we now switch the left one back on you'll see that the master is staying on the side that has been switched up first so in this case the right side we can put both of them off then of course we don't get a master light either anymore there is one exception where the master light is going to come on on both sides and that's with the approach mode engaged and final approach because then you get independent flight director operations moving on we have the auto throttle arm switch going to put this on and you can see the green light here and the green light just like on all the other buttons for example if we take heading select here as well it does not indicate engagement or correct operation of the mode all the green light is telling you is that by pressing the switch again you can deselect the mode so if we look for example at the heading select button that we've just engaged you can see heading select on the flight mode enunciator and if i press this again now the mode disappears so that is all that the green light is showing you the only way to determine if a mode has correctly engaged is by looking at the flight mode enunciator at the top of each primary flight display i'm going to give you an example now let's press lnf you can see the green light coming on but looking at the pr primary flight display in the flight mode enunciator you can see that lnf has only armed but not engaged yet despite the green light showing and that is because if i press the button again now i can deselect lvf so let's move on order throttle arm switch this basically arms the auto throttle for engagement you can verify it on the primary flight display by the arm indication showing and the auto throttle is then going to engage when any of the following flight director modes are engaged level change altitude acquire vertical speed v nav altitude hold glide slope capture or toga note that if the auto throttle is armed and arm mode is shown in here it also provides a low speed protection if you were in flight and went into low speed situation then the auto throttle would automatically come on and put your engine thrust up versus with the auto throttle not armed in the off position that is not going to happen next up is the n1 switch and this will engage the ultra throttle in n1 mode so basically the auto throttle maintains first at the m1 limit selected from the fmc and shown up here on the engine display so right now the limit is full take off thrust so if the auto throttle was armed and we would push the n1 switch then the engines would spool up all the way to the um take off thrust limit moving on we have the speed switch the speed switch engages the auto throttle in speed mode if a compatible other auto flight director mode is engaged so for example if you are a level change and then you press speed those modes would contradict each other and nothing would happen but if you were for example in vertical speed and you press the speed mode then the auto throttle is going to engage in the mcp's beat mode which is then going to maintain the speed selected in the window up here note that in this mode a low speed protection is provided moving on we have the changeover button and all this does is to change between indicated airspeed or mach number so if you're in flight at high altitude then your airplane is going to fly on a mach number for example 0.77 and if you want to change the command from the mach number to an indicated airspeed press the changeover button the speed dial is simply changing the speed you have over here or the mach number depending on which mode the speed window is in speed intervent the next button is a function that if the speed window is closed meaning if there is no speed shown over there which is normally the case in either toga mode or in venus operation then the speed window is going to open up so show you a speed when you press this button and then you're able to manipulate the speed yourself the next button here is level change and level change basically tells the airplane i want to go to the target altitude in the shortest or in the most efficient way so if your altitude is set to an altitude above your current altitude and you engage level change then your airplane is going to maintain the target airspeed by changing its pitch note that if the altitude is above your current altitude level change is not going to start to descend and the other way around if the altitude on the mcp is below your current altitude the airplane is not going to start to climb if the auto throttle is engaged together with level change then the auto throttle is going to switch either to n1 mode if a climb is commanded thereby adding full thrust to the engines and then maintain the speed by increasing pitch as necessary and if the auto throttle is engaged while level change is pressed for a descent it's going to go into a mode and your thrust levers to idle and then into arm mode once the thrust has reached idle and then it's going to descend while maintaining the selected speed moving on we have vertical navigation that is a little bit more complex mode and it's comparable to the climb or descent modes in an airbus if you are more familiar with that just like level change is comparable to open climber open descent in the airbus what vnev is doing is that it's basically automatically determining the climb or descent profile using your fmc data so if we would use vna for climb then it would take the target speed from the climb page so 286 knots or mach 0.771 while also respecting the speed restriction entered here so 250 knots below 10 000 feet and then wiener is going to climb to the mcp selected altitudes using using the speed schedule that's defined in here and note that vnav is also going to adhere to all the constraints that we have in our legs page so you can see we have a speed restriction here of 210 knots and we have altitude restrictions to cross the particular waypoints above particular altitudes veenaf is going to take care of all of those provided your airplane has enough energy to do so so what does that mean if we were to use vina for the takeoff then after flap retraction it would maintain a speed of 210 knots and give us the best possible climb similar to level change by adding maximum frost and then maintaining the airspeed by pitching the airplane up or down but it is going to make sure that it will pass above those altitude restrictions and if it's not able to do so you're going to get a message in the scratch pad down here for example unable altitude at whiskey india 505. note that you have two prompts on the vnf client page in the fmc which are maximum rate and maximum angle if you go for maximum rate note how the target speed is changing and now the new speed if you execute this is going to give you the best possible vertical speed meaning that you are going to reach your target altitude in the shortest possible time versus if you were to use maximum angle you can see the speed is even slightly slower because now the airplane is going to reach the target altitude in the least possible distance so i'm going to erase that for a short moment to recap maximum rate is giving you the shortest possible time or maximum angle is giving you the shortest possible distance moving on to venus in the cruise phase in cruise flight venus is going to maintain the economic mach number that's been determined by the flight management computer now let's move on to the descent phase of flight still in venus mode there are basically two v-nerf modes for the descent one of them is v enough speed the other is the enough path the default mode should be the enough path and that indicates that the airplane is following the optimum descent path that has been calculated by the fmc and while it is following that path it is going to accept a certain deviation in the speed before it is going to correct your airspeed in either case though an overspeed protection and an underspeed protection is provided so if you were to overspeed the airplane would change from vnav to level change and then start to climb automatically to reduce the airspeed well if you were to go too slow it would change from v enough to level change and then pitch down in order to regain airspeed so in venus path mode venus is basically following the predetermined descent path from the fmc however if you engage vnev well you are not on the descent path then it is going to go into venus speed mode just like if you are flying on the venus path and now you are deviating from the path for whatever reason then it might revert into venus speed again the only way to tell in which mode you are is by looking at the flight mode enunciator which is going to show you the exact mode venus is operating in so if you are in venus speed mode in a descent then it is going to set the thrust to idle provided the auto throttle is on and then maintain the target speed that you can see in the flight management computer on the descent page over here so in our case it would maintain a mach number of 0.768 until the indicated airspeed reaches 252 knots and then i would continue the descent at 252 knots until at flight level 100 it would reduce the speed to 240 knots be aware that in vino sorry in venus speed you are not necessarily going to re-intercept the v-neck path but it might just parallel the path if you are above it if you engage vena while you are below the optimal descent path in the descent then the airplane is going to descend at 1 000 feet per minute until it re-intercepts the path let's move on the next button we have is heading select hiding select is a pretty easy mode it is simply going to maintain the heading that is set up here moving on we have a dial to change the target heading as you can see me doing right now and then we have the angle of bank selector that one controls how much bank the airplane can use in heading select mode so right now it's set to the default value of 25 degrees of bank you can set it up to 30 degrees and you can set it in a 5 degree step to as low as 10 degrees so we have 10 15 20 25 30. when you are operating above flight level 300 you should set this to 10 degrees angle of bank moving on we have lnf that's lateral navigation and if you're used to airbus it's similar to the nav mode in the airbus so enough mode is going to follow the predetermined track that you have programmed into your fmc and elna got an automatic bank angle limiter function so if you're using lnf the airplane calculates in real time how much bank angle it can use before exceeding any buffeting limits the maximum however is 30 degrees angle of bank with a slight overshoot happening sometimes so there are certain criteria for lnf in order to engage when you're on the ground you have to have an origin runway in the fly plan and the route has to be active and executed in the fmc the track of the first lag has to be within five degrees of the runway heading both flight director switches have to be on and if elnav has been selected prior to engaging the takeoff go around mode then ln of guidance becomes active at 50 feet remember if we press the button we can see it arm on the flight mode announce theater here and when we are passing 50 feet in the climb the motor is going to become active in flight there is a couple of additional criteria for enough to engage an active route has to be entered in the flight management computer if you are within three nautical miles of the active route elephant will engage on any airplane heading but if you are more than three miles away from the active route entered in the flight management computer you must be on an intercept course to the enough track of 90 degrees or less and you must intercept the route before the active waypoint so let's say that you are that you've received radar vectors from atc and now you have already passed the active waypoint on a heading but the fmc has not switched the active waypoint yet the active waypoint can always be seen on the top right of the navigation display as well as on the top of the lacks page in the fmc then you might just want to take the next waypoint and enter a direct2 so that there is a route available again for enough to intercept whenever you have entered the direct 2 lnf should be available for engagement if you do it promptly after entering and executing the direct and finally enough can also automatically disconnect and it will do that follow for the following reasons either when you reach the end of the active route when you reach a route discontinuity when you intercept a selected approach course in either vo or localizer or approach modes when you select heading select or when the capture criteria is lost so to summarize lnf you should be on an intercept course to the active fmc route when you press lnf then the fmc and then the autopilot is going to follow the route programmed in the fmc next up we have the vor localizer mode in short warlock and that mode is basically commanding the autopilot to intercept whichever localizer of your r has been tuned on either radio so when the left side is the master this is going to follow the left course and the left navigation radio the number one radio and when the right flight director is master like it is now then it would follow the right course or the and the right radio so always keep an eye on the master switch here if you're using warlock the master light has to be illuminated on the side of the radio that you want to use similarly if we look at the approach button it got all the horizontal navigational functions of the warlock mode and it is also going to follow the glide slope and once again it is going to use the data of the site that is master in order to [Music] navigate the approach button however got an additional function if you have programmed a non-precision approach in the fmc and there is no valid localizer or glidelobe signal then pressing the approach button is going to arm the ian mode and what that one is doing you have to carefully check when you press the approach button on the fma which modes have armed it is either going to be warlock and glideslope in white in that case the approach mode is going to capture localizer or glide slope in order for these modes to arm you have to receive and i repeat you have to receive not just tuned but actually receive a valid localizer and glide slope signal if the airplane does not receive a localizer glideslope then you will see a different fma and that is fac final approach cores and gp glide path versus gs for glide slope in the vertical modes final approach course fac contrary to warlock is going to position you on the extended runway center line that's inserted in the fmc and it is going to fake a localizer signal on your pfd so be very careful with that mode if it enters fac mode but you want to fly an ils then you'll have to disengage the mode again by pressing the button again and wait until you receive valid localizer signals now it can happen that you receive a localizer before you receive a glide slope and if you're on the approach modes while you have localizer while you receive a localizer but not the glide slope then the vertical mode that's going to arm is going to be g p papa which is glide path in that case the airplane is going to use the vertical profile from the final approach to create an artificial glide slope for you that's going to lead you to the runway but it is not going to follow the glide slope so once again be careful that you only on the approach mode when you are receiving both localizer and glideslope indications if you were to fly a non-precision approach and your arm approach mode then it is going to enter the final approach course and glide path modes which are basically an attempt of the airplane to create an ils looking symbology on the primary flight display for you to follow on your non-precision approach moving on we have the altitude hold button and that's as easy as it says you press the button and the airplane is going to level off at the altitude that you have been passing in the climate descent whenever altitude hold is engaged note that if you are currently climbing and you engage altitude hold it is going to descend back to the very altitude where you press the button and similarly if you're descending and you press the button it's going to climb back to the altitude that you've been passing when the button has been pressed then we have our vertical speed button and in vertical speed mode the airplane is going to follow the vertical speed that will be commanded in here note that right now there is no value shown but as soon as we press vertical speed the number is shown here and can be changed by this dial below 1000 feet a minute it changes in 50 footsteps and above that in 100 footsteps contrary to the airbus there is no flight path angle mode available in the 737 so you can only set the vertical speed and not a flight path angle moving up we have the altitude selector knob this one changes the altitude in 100 foot steps and finally we have altitude intervent altitude intervent is a little bit of a more complex mode here so altitude intervent is basically being used in vnf mode and let's take an example in a climb you have your altitude here set to 13 000 feet now let's assume we had an altitude restriction of 8 000 feet or less at a waypoint over here in that case pressing altitude intervent in the climb is going to cancel all the altitude restrictions here until the altitude you have set in your mcp one at a time so if you press this button now you see it remove the first altitude if i press it again it's moving the second altitude again it's removing the fourth and so on but note that when i press it now it is not going to remove the 130 restriction since that at or above the mcp altitude if we are in a descent it works slightly different first of all it got the capability to do the same thing that we've just did here just vice versa in a descent so if your mcp altitude is selected below a descent constraint and you press altitude intervened then that constraint is going to be removed however in the descent it also got another function if you are in venus mode and the mcp altitude is set for example to your current level while you are passing the top of descent then you will see the flight mode enunciator change from venus path into venus alt and venus alt means that it's going to maintain the current or not the current but the altitude that vena wants to maintain so for example if we are in cruise flight we're passing the top of descent but the mcp altitude is still set to our cruise level then it is going to change from the enough path to vena faults if you then set the v if you then set the mcp altitude down to a lower altitude it is going to stay in venus alt mode if you then press altitude in event it's going to change into venus speed and start descending finally moving over to the autopilot engagement panel over here we have our command a and b buttons and those are basically going to engage the autopilot on the respective side so if the captain is part of flying he should always be using command a if the first officer's part of flying he should be using command b and the reason for this is that if you engage command a the left side is automatically going to become the master side if you engage command b the right side will automatically become the master side and this cannot be changed so if we for example engage command b now you will see how this changes to master and now even if i turn the flight director switch off on the side then you will see that it stays master on this side let's disengage this again and similarly if i now engage command a you will see that the left hand side is becoming the master side moving down we have control wheel steering mode which is what we like to call the airbus mode in control wheel steering you are still controlling the airplane using your control column so your normal flight controls but the autopilot is going to hold the pitch attitude and the bank angle for you with a bank angle there's a small specialty there and that if the autopilot is engaged in control wheel steering and you have a bank angle of 6 degrees or less then it's automatically going to roll wings level for you finally we have the autopilot disengage bar note that this is not the primary means of autopilot disengagement but it provides an alternate means of autopilot disengagement so if we have an autopilot active like this and we put the disengage bar down the autopilot is going to disengage so this basically covers all the buttons we have on our mcp so let's give us a quick review to recap all of the um information that we went over now and one mode is going to apply thrust provided the auto throttle is armed to the maximum that's um shown on the engine display here speed mode provided engagement criteria as matte is going to adjust engine thrust in order to maintain the speed that's selected up here level change in a climb is going to apply maximum thrust under the um limiting condition of course and then adjust this pitch in order to maintain the speed selected up here the vnav is going to follow the vertical part of your flight plan in the fmc lnf is going to follow the lateral part of the flight plan in the fmc heading select is simply going to follow the heading warlock is able to follow either a vor radial or a localizer and makes use of the master side on each side approach mode similarly to warlock is going to follow the lateral guidance but also the vertical guidance from the glideslope and approach mode can also arm the ian mode in which the airplane is going to fake localizer and glideslope indications for a non-precision approach where there is no actual localizer or glideslope available altitude hold is simply going to maintain the altitude that you have select that you are passing or maintaining by the time the button is pushed vertical speed is going to make the airplane follow a certain vertical speed that you can set in the vertical speed window up here i hope you found this useful and i hope that i didn't overload you with information here on the different modes if i did please let me know in the comments if you like it also let me know in the comments and if you think i should immediately burn my computer because this is total nonsense that i'm saying please also let me know in the comments thank you very much and i hope to see you again on a future tutorial

Channel: A330 Driver | 737NG Driver

Views: 35,064

Keywords: PMDG, PMDG 737, PMDG 737-700, PMDG MSFS, PMDG 737 MSFS, PMDG 737 Failures, Dual FMC Failure

Id: Lk8LYlIsyJc

Length: 36min 50sec (2210 seconds)

Published: Mon May 23 2022