In one of the airlines I worked for we were supposed to increase the cost index in case of a delay… there were fix numbers there.
Other airlines would just say you may increase it (or directly the speeds) for a valid reason… but leave the rest on the pilots.
And of course there are companies where you’re not supposed to change it at all.
Umbrella Flight -redacted- is ready to deliver some B.O.W. to the San Francisco Nemesis Labs Inc.
I don´t know why but I just think that plane should be black. With it´s lights off, and two black SUV´s parking next to it… But that´s just some strange idea that came to my mind.
But I heard that the old CFM56 have flame-outs in this harsh strong rain conditions, must the engine condition set to “continuous ignition” CONT while flying?
The rain is really brutal tonight, and fog for a nice CAT3-B landing is predicted in San Francisco…
Why doesn’t the PMDG 737 cockpit doesn’t have head displays? While the real plane carries them?
The HUD is an option for the captain’s side. it’s set per-livery and can be enabled or disabled in the FMC menus, as described in the Introduction PDF document included with the plane.
My medium-sized freighter does not have a HUD but the pure glory of these panorama windows.
The big -800 freight ship has the HUD enabled (and the other goodies like the LED-stobes), all this can be installed with one click in Aircraft Options in the FMC.
It is not called HUD there but some stupid name nobody uses, I don´t remember but something like “FTH” or whatever. But in reality this is of course called a “HUD” since the seventies 
We don’t change the cost index in the middle of a flight. In our case we set the cost index given to us in the operational flight plan for every flight and we keep it like that for the whole flight. Normally we always use the same cost index. In my airline, 99.9% of the times this is cost index 6.
You ask if we change CI during the different phases of a flight. That is not necessary. CI simply gives you speeds and mach numbers for your 3 phases of flight (climb, cruise and descent). This speeds become “econ” speeds. Whenever we’re required to fly a different speed, either by ATC or by us for energy management, we simply fly non econ speeds by typing a new speed in the FMC or by using a mode that lets us dial a speed on the MCP. For a short while our airline tested a technique called “opti-climb” where we would be given different speeds to use during the climb. These speeds were selected in the FMC as the airplane climbed on VNAV SPD. I believe it didn’t prove to be cost effective so the procedure didn’t end up in our operations manual.
On rare occasions where we have a significant delay that conflicts with Flight Time Duty Limitations or when the destination airport has runway closure after a certain time we may be given a higher cost index. In our case this is normally cost index 100. In 5 years in my current airline I’ve only use Cost Index 100 on 4 occasions. It’s not fun to fly that fast in the 737 as you’ll have a very small margin to MMo during cruise and pilots will have to stare at the airspeed during the whole cruise and intervene a few times whenever a change in wind brings the airplane too close to the clacker. The autothrottle in the 737 is very lazy.
I fly 800s and MAXs. The same cost index results in different speeds between the 800 and the MAX. Our MAXs flies faster during cruise but slower on descents than the 800 at the same CI. But I believe the CI tables are modifiable by the airline so cost index 6 in one airline may result in different speeds than in another airline.
We wouldn’t dial in an altitude lower than ATC has cleared us to even when using VNAV and even when there’s an altitude restriction in the legs page. With ADS-B, ATC can see what you have selected on the MCP. They want to see the levels, waypoints or headings that they’ve cleared you to and they’ll usually get your attention if you’ve selected an incorrect value.
If ATC clears us to an altitude lower than the restriction on a point ahead of us we’ll still select on the MCP the level that ATC has cleared us to. We usually know if they still want us to respect that altitude restriction. If we’re not sure we may ask “are we still required FLXXX at point YYY?”. They may say yes or they may give us unrestricted descent. Sometimes they’re specific with descent clearances and they may say “Descend FL150, cross point XXX at FL190 or below”. Or “descend FL190 to be level by point XXX” or “Descend FL150 at 1500fpm or more”.
During the last portions of descent we may be cleared for approach when there are still a few altitude restrictions ahead. In this case, the “cleared for approach” part of the clearance means that we must follow both lateral and vertical path as per the chart. In our airline we will select on the MCP the level we’re required to respect on the point ahead of us. So if the point ahead has 5000A, we will select 5000 on the MCP. If after that point there’s a FAF at 3000ft, we will usualy wait until we’re 1nm from the point restricting us to 5000A, and there we will select 3000 on the MCP to continue descending. We’ll do it like that until we reach final approach vertical guidance (after the FAP/FAF) on ILS and NPA approaches where in most cases the vertical guidance will be geometrical. On NPAs, 2nm before the FAF we will select on the MCP the minimums rounded up and shoot the approach in VNAV PTH with SPD INTV and then generally at 1000ft AAL we’ll select the missed approach altitude.
Yes but remember we do it on the 737 because it doesn’t have an AUTO position on the bank angle selector. Also, the bank angle selector only limits the bank angle on turns flown in HDG SEL (It does not affect LNAV bank angles). During the cruise we use HDG SEL whenever ATC gives us a heading for separation or whenever we need to avoid weather and request a heading to ATC.
LNAV does have bank angle protection so any turns during cruise that result in a large turn may be flown by the autopilot with bank angles higher than 10º and that is perfectly safe.
Ah I see. Thanks for the info. I always thought that perhaps steeper turns at higher altitudes carried an increased chance of the wings losing lift, with the thinner air.
Where are those extra windows in the exterior model?
The eyebrow windows become also visible in the exterior model of course. Otherwise that would look kinda strange
This panoramic view is a pure blast while flying!
When having the eyebrow windows disabled they become blind white-tinted glass on the outside, almost invisible.
Ah I remember while the 737 was in development the most important first question was: Will these rooftop panorama windows be there? So awesome flying through a thunderstorm with these windows, they give the cockpit such a uniqué feeling of sitting under a glass dome.
(I evaluate a cockpit not only by the features and high-tech it has, but also by the pure looks: How does it feel sitting inside there, how would it feel when sitting in the real deal either in the real airplane, or in this cockpit with a VR headset on?)
And the 737 is pure AWESOMNESS!!
Fascinating. So ATC can actually monitor what settings you have selected in the cockpit? That’s truly amazing. Is this done via some sort of computer app that flags conflicting MCP settings to a controller or is all of this displayed for every flight they are tracking (no idea if you have much info on that side of the aviation house).
On Cost Index, assume the higher the number, the faster the speed / rate of climb? I read somewhere that SWA mandates “40”. That seems pretty low. Is that about the lowest cost index being used?
Question on selecting bank angle - how is this done? I haven’t been able find this.
Last noob question - what’s the difference on the various starter modes (Auto/Cont/Flight)?
I’m sorry to post such basic questions, any info on any of these is greatly appreciated.
@FaultedBirch573 I know your questions are for FormerSnail5736 but regarding the bank angle selector:
On Collins MCP:
On Honeywell MCP:
GND is use for engine start on the ground
CONT is used to turn on one igniter system and used for take and landing (to prevent possible flameout)
FLT is used to turn on both igniter systems and usually used for engine start at altitude or high-risk flameout scenarios
If I remember correctly ATC can only see your selected altitude as per the MCP.
You’re right re the cost index, the higher the number the faster the commanded speed. 40 sounds perfectly normal for a 737 as I remember it but every airline will have it’s own and it’s own reason for using it.
Generally the cost index appears on the flight-plan and we fly it as published 98% of the time. Most of the time there will be a fleet standard index but the flight planning dept may vary that based on prevailing conditions as and when required. If we then feel it necessary on the day to fly a different speed for a myriad of other operational reasons then thankfully it’s in our gift to do so. Irrespective of the Cost Index we will generally always overwrite the descent speed with something sensible as it is often way too slow or fast. Our standard Index regularly gives a descent IAS of around 260kts which is too slow in almost every situation.
Just around this bigger point, ultimately you cannot write an SOP for everything and it comes down (or should come down) to the training, experience and airmanship of the guys and girls flying the aircraft. I would hope that operators empower their flight crew to make decisions (thankfully I fly for an airline that does just that) and as long as you can, if asked, demonstrate that something has been thought through and is justifiable then they wouldn’t bat an eyelid. On the flipside, if someone habitually flew much faster than standard (constantly burning more fuel and increasing engine wear) ‘just because’ then they would understandably want to know why.
With the advent of Mode S, where I used to work, Terminal Control at Swanwick Centre in the UK, there was some automatic highlighting if what was selected in the cockpit was different than what was expected depending on the parameter. Such as if QNH set in cockpit was different from the actual QNH. Otherwise we were just able to see the selected value, plus also certain other downlinked information. As well as allowing the above, it also meant tools such as the Vertical Stack List could be developed, not possible with ‘basic’ SSR.
An article written some time ago shows a couple of pictures of the TC radar displays back then, don’t think current ones are much different.
Mode S downlinking has also allowed the development of further tools, such as Intelligent Approach…
Stall speed is dependant on load factor. Load factor is directly proportional to bank angle. At 60º of bank the load factor will always be 2g. At 25º of bank the load factor on a stable straight and level turn is 1.103g. The top of the amber airspeed band indicates the 1.3g manoeuvre margin to stick shaker. If you fly that speed and your load factor increases to 1.3G you’ll get stick shaker. So basically if you’re at high altitude turning with a high bank angle and a gust increases your load factor by not that much you could potentially get a margin of less than 1.3g to stick shaker. In turbulence you could briefly enter the amber band and hear “airspeed low” warning and buffet alert message in the CDU. It’s very unlikely but likely enough for some operators to want to limit the bank angle to 10º above a certain altitude to increase load factor margin to low speed warnings.
That’s part of what ADS-B does. Automatic Dependent Surveillance–Broadcast - Wikipedia
Yes, the higher the cost index the faster speeds the airplane will fly during climb, cruise and descent. But the second part of your paragraph is wrong. On climbs we’re flying VNAV SPD. The faster you fly the lower the vertical speed will be. At Cost Index 100 the airplane will take a longer time to reach the cruising altitude than at Cost Index 1. Best rate speed is just slightly faster than the UP speed and can be selected in the VNAV CLB page. On descents, the faster the speed the higher the descent rate will be because drag will be higher.
Cost Index is programmable by the airline. It’s irrelevant what number they use. The Cost Index tables are completely modifiable by the operator. The 737 does not have a huge range of flyable cruise speeds (Low Mmo) so cost index doesn’t affect our cruising speed so much. It makes a bigger difference during climbs and descents. Remember time is rarely saved in flight. Time is saved on the ground. It doesn’t make a huge difference to fly faster or lower in cruise and fuel consumption will not vary significantly from the pilots perspective on a flight per flight basis. These are things that the airline does looking at yearly fuel consumptions. The 737 is a short/medium haul airplane. The difference between flying .76 or .79 on a typical 2 hour flight will be just a few minutes. In long haul airplanes it’s a whole different story and they usually have a much larger speed range they can use in the cruise.
The heading selector has a ring around it for that purpose.
You can find that in detail in the FCOM (http://www.737ng.co.uk/737NG%20POH.pdf) and it would be better for you to obtain the answer from there than from here. (Chapter 7, Section 15, Engine Start Switches)
Autobrakes never work on either -700 and -800. Or do they but they’re very weak?
As always, thanks for the detailed response. I had no idea this data was made available to ATC. Your explanation on descending to an ATC cleared altitude makes perfect sense. I was also interested in what your SOP might say for handling the “descend via” instruction. There ATC pretty much now expects you to descend to hit the published restrictions on the way down. So in that scenario, would you dial the “next” restriction and keep resetting a lower altitude, or, would you simply dial in the lowest restriction on the STAR until hitting the end or modifying based on another ATC instruction?
