Comparisons to RL

[Alec 370]

Just incredible informations. Every time you add more text, I can't wait to read it and go for a flight on the NGX. One thing I noticed. Is that 737NG using a 737-300/400/500 FMC? I've never seen that before

[ARM505 0]

Simon, really enjoying reading this (btw, former SA native from Germiston, now living in Canada). In the highlighted text above, are you saying that the aircraft if flying the lateral path even though the A/P is off or that the FMC is showing the way but you are actually flying the lateral and vertical path manually ? regards, Mark.

Sorry, that part wasn't clearly written - we're still hand flying (FD annunciated over the PFD) and in LNAV roll mode - so the FMC is commanding the FD bars to give us roll guidance to keep on the programmed path - in this case the SID. But of course we have to manually control the aircraft and keep the FD bars centered by hand if we want to actually do this. In pitch, TOGA pitch mode won't follow the planned vertical track that's in the FMC of course, it will just command a certain pitch attitude - but of course once again, since we are hand flying, we have to keep the FD bars centered IF we want to do this (sometimes it's handy to be able to 'look through' the FD and ignore it if it's giving you something you don't want to do)

Just incredible informations. Every time you add more text, I can't wait to read it and go for a flight on the NGX. One thing I noticed. Is that 737NG using a 737-300/400/500 FMC? I've never seen that before

Well spotted - the physical parts are actually interchangeable. Technically thats actually just a CDU (control display unit) though, not actually the FMC which sits in the E&E bay under the cockpit. Did I use enough acronyms in that sentence? Not sure.... :) So yes, the older CDU's are interchangeable with the newer aircraft. Handy when you're operating a mixed fleet.

[Houghton11 12]

Simon, this NEEDS to be a sticky. If there was any way I could buy ya's a beer even way over there i'd do it...hehe. Very informative!

[MarkW 1,494]

Sorry, that part wasn't clearly written - we're still hand flying (FD annunciated over the PFD) and in LNAV roll mode - so the FMC is commanding the FD bars to give us roll guidance to keep on the programmed path - in this case the SID. But of course we have to manually control the aircraft and keep the FD bars centered by hand if we want to actually do this. In pitch, TOGA pitch mode won't follow the planned vertical track that's in the FMC of course, it will just command a certain pitch attitude - but of course once again, since we are hand flying, we have to keep the FD bars centered IF we want to do this (sometimes it's handy to be able to 'look through' the FD and ignore it if it's giving you something you don't want to do)

Thanks for the clarification, makes much more sense now! Mark.

[Houghton11 12]

...and make sure that there is bleed air to pressurise the boilers for water....

whhoa wha what? Now I don't get to play around the galleys of big things much but are you serious? That's crazy..haha...

[ARM505 0]

whhoa wha what? Now I don't get to play around the galleys of big things much but are you serious? That's crazy..haha...

Hmmmm.....now that I think about this, to be honest I (shockingly) can't remember whether the water heaters are fed directly from the potable water system, or whether the cabin crew have to actually put water in them themselves....either way, they need bleed air pressure in the system to provide pressure to get the potable water out! I've made a point of doing this all from memory - don't make me go and look up how the potable water system works now! :)

[Houghton11 12]

Ahh okay that makes sense yes. Don't worry I'll dig... I thought there was some funky bleed-boiling system which pressurized the boilers or something to induce boiling...hahaha..or created some vacuum and let water boil on its own? Haha EDIT: From the 3/4/5 but probably similar -

...The passenger water tank is normally pressurized by engine bleed air taken from the pneumaticmanifold which pressurizes the APU manifold to move fresh water from the water tank to thelavatories and galleys. The water tank pressurization system includes check valves, an air filter, apressure regulator, and a pressure relief valve....

Or there can be an option for a compressor to augment things when bleed pressures low too... naarrr nerdy..haha

[lbarber 20]

Question on the boilers which I haven't come across in the manuals: you mention these are bleed air powered. How does this work? I'm assuming that if you're using GPU + Ground A/C (no APU running) you'd have no way of making coffee. That sounds like a terrible proposition and a rather costly cuppa if you've got to run the APU just for the galleys. edit: beaten x2, that's what I get for starting on a reply before lunch and posting two hours later.

[WotanUK 289]

Although it has been said numerous times already. Thank you for taking the time to share this with us.

[Tabs 2,790]

Simon,Check your forum PMs.

[Houghton11 12]

He he he something's afoot...

[PIC007 82]

I'm thinking Simon just won the "Thread of the Year' award and a 'prize' is on the way

[Airbus Commander 563]

Question on the boilers which I haven't come across in the manuals: you mention these are bleed air powered. How does this work? I'm assuming that if you're using GPU + Ground A/C (no APU running) you'd have no way of making coffee. That sounds like a terrible proposition and a rather costly cuppa if you've got to run the APU just for the galleys.

Well, AFAIK, the water system is able to be pressurised by the external air coming from the cart, excuse me if that is wrong, It's been a while since I've actually flown the 737 IRL so don't hold that to me but I'm 99.99999999999999999999999% sure, I'm sure Simon can correct me if I'm wrong.

They definitely do! But.....we don't I think I mentioned somewhere amongst the million words I've written that we don't in order to keep the operation as standard as possible between fleets - we can hop from a B737-300 into an -800 in one day,

I see Simon that yee fly both the classics and NGs at your company, you wouldn't happen to have an electronic copy of the differences hand out you got during your training would you? I've been looking all around the internet for one but just can't lay my hands on it, it'd be really appreciated if you could e-mail one to me as I was going through the FCTM and FCOM for the NG and almost everything is the same or very close to the old classics, If I could just get the differences course it'd save me a load of time. If ya have it, could you drop me a PM and I'll give you my email address. Thanks in advanceRónán.

[MarkW 1,494]

He he he something's afoot...

Here's my guess. - PMDG supplies a nice new copy of the NGX to Simon. - Simon writes the detailed full Tutorial #2. OK so what do I win ?

[ARM505 0]

The following is a bit of a long-winded blah blah, but there's actually a lot of stuff happening now so it's hard not to go on and on - sorry! ..and back to our intrepid crew, who by now are getting pretty close to the airfield. Hopefully they haven't botched it, and are reasonably set up for either a visual approach, or ready to catch the localiser for an ILS approach. Or, as often happens, a visual approach backed up by the ILS, ie we will call the field in sight within 25nm, and be cleared for a visual approach (and are therefore responsible for keeping ourselves clear of terrain), but will still use the ILS for reference to improve our approach. This can be hand flown if desired, but an ILS approach in IMC (instrument conditions), or with a high crew workload will be flown with all the automation available to us. Passing FL150 on the way down we enter our 'safety window', and we only talk about the task at hand. No more major programming of the FMC - it can too easily become a distraction from the primary task of flying the aircraft. The old rule of 'Aviate, Navigate, Communicate'....Passing FL100 the PM will switch on the landing lights to improve other peoples chances of seeing us, and we will often have to slow down to 250KIAS passing FL100 as well, if we haven't already done so. It's also correct to check that the cabin pressurisation is well on it's way to gettting the cabin down to the appropriate altitude for landing. The ACAS traffic display will often be getting pretty busy now, and we will be handed over from the area to the approach controller in most cases. Depending on the amount of traffic, the conversations can be pretty rapid fire now, and missing calls or hmmming and hawing on the radio at this stage is asking for trouble. Sometimes even getting your initial call in can take a while, and ATC may end up calling you before you get a chance to call them. At this point you're almost certainly going to start getting vectors and specific airspeeds as well, as ATC finds a hole for you - meanwhile, you need to constantly monitor how the approach is going in terms of energy levels. If you need to be faster/slower than what ATC is giving you, you're going to have to let them know. If you have the field in sight, asking for a visual can help ATC since they no longer have to constantly steer you around - however if it's busy, it can sound like a hilariously unsubtle attempt to jump the queue, that is doomed to fail :) Johannesburg is the prime candidate for crazy levels of business, since ATC are pretty short-staffed, and often one guy is handling the whole terminal area, but it's normally not too bad. The smaller airfields can be very relaxed, with the approach controllers first words to you being 'Cleared direct to a 10 mile centre fix, no speeds, visual approach available on request!' which is first prize. Since we're almost certainly off the STAR by now, and probably getting specific airspeeds, we'll probably be flying on HDG select and SPEED or LVL CHG mode and may have kicked the A/P out to hand fly. Cue A/P disconnect warning horn, and frantic pressing of the disconnect button to make it shut up. If we're cleared for the visual approach, we're going to be making a lot of small heading changes and the PF will often ask for the FD's to be switched off as well, so we end up flying 'raw data' (oooh!) which is important to do to keep your eye in IMHO. No more cues from the flight director. The PF will call 'Set runway heading, Set missed approach altitude', just so we've got those references should we need to go around at any stage. The aircraft still needs to be configured for the landing of course. Once below 250KIAS, flaps can start to be extended, but sticking them out precisely on the limit is to be avoided if possible to reduce the aerodynamic loads on them and extend their lifespan. Ideally, we'd like to extend flaps about 10knots above the manoevring speed for the current setting (ie assuming a minimum clean speed on the speed tape of 212KIAS, extend flap 1 at approx 222KIAS if you plan on slowing below 212) The PF calls for the flap setting, and the PM moves the lever and automatically sets the manoevring speed for that flap setting (unless instructed otherwise by the PF), which is shown on the speed tape. Once the flaps roll to the selected setting, the PM calls 'Flap XX, green light', the 'green light' indicating the LE device annunciation just below the flap gauge (assuming it is actually green!) Flaps provide useful drag to help us slow the aircraft down now - trying to get down the glideslope in a clean configuration can be very difficult (if not impossible) without building up speed, especially if the aircraft is heavy. If doing a tight visual approach, or an ILS on a reasonably clear day, its best to capture the localiser at minimum clean speed (certainly nothing above 250KIAS, which is pretty adventurous anyway) and get to at least Flap 5 before capturing the glideslope (GS) which really shouldn't be allowed to happen at greater than about 210KIAS. Doing a serious ILS in IMC, depending on the range at which you capture the glideslope, you're probably going to want to have the gear down and be at Flap 15 (at least) already. Once ATC gives you the final heading to intercept the localiser, VORLOC can be armed if you're still using the A/P or FD - this will show as white text saying 'VOR/LOC' mode below the current roll mode, if any, and will become active as you intercept the localiser. The A/P will roll the aircraft to maintain the localiser, or if using the FD, the bars will show the required roll to maintain it. The APP mode can now be armed, which will show 'G/S' in white below the current pitch mode. A quick note here - pressing APP directly, instead of going via VOR/LOC first, then APP (which will just get G/S armed then) is frowned upon with us, but that's basically only because in the older aircraft that we used to operate if you did that the aircraft would capture the glideslope without necessarily being on the localiser first, and start descending despite not being on a known lateral path (ie not safe to descend). The newer aircraft don't do this - VOR/LOC must be active before G/S can be active, thus precluding an unsafe descent. Nonetheless, we still operate as if that could be a threat (old company habits die hard I guess) It's not hard to do in any case. (Edit to add: I think this is actually an option, but one that all our newer aircraft have...more research required here) Once the glideslope (or if visually descending on the estimated glidepath) has been captured, and inside of ten miles it's time to start thinking about getting fully configured - maybe even earlier if you're very heavy and there's a slight tailwind or some other factor. If in doubt, configure a little earlier. Leaving it until the last second is asking for trouble, but naturally it saves time and fuel to get it done at the optimum moment. The PF will call for the gear down, and often Flap 15 at almost the same time. Of course, this is when ATC often subjects us to yet another frequency change, from the approach controller to the tower controller! With the PF's call of Flaps 15, the PM will have quick series of actions to perform - the start switches will be switched to CONT, the MC recall will be checked, and the speed setting in the speed window will be set to Flap 15 manoevring speed. He/she will then call 'Gear down' (after checking that it is in fact showing all green!) and 'Flap 15 green light', as normal. The PF will arm the speedbrake by pulling it out of it's detent until the 'Speed Brake Armed' light illuminates. Surprisingly, even if you forget this action, as soon as you pull the thrust levers into reverse on the ground, they'll come up anyway. Clever Boeing! Now the flaps are starting to add a decent amount of drag to the aircraft, and it should manage to slow down without trouble. Having said that, if you've overcooked it, now is the time that it'll really become apparent, since you won't be able to slow very easily to get withing the Flap 15 limit speed (200KIAS if memory serves) Handily, all these limits are nicely presented on the speed tape as the upper red line moves downwards, and what's more (bonus knowledge!), the amber band represents the limit speed for the next flap setting! Except for Flap 25....but I won't confuse the issue now. All very easy to see. Which makes the excuses even harder should you bust any of the limits! We have a quirky habit of going to Flap 25 at this point, but you can actually just go straight to Flap 30. Now the target (or 'bug') speed must be set. The basic plan is to add 5 knots to your calculated Vref. If I haven't mentioned this already (I have a sneaky feeling I didn't), prior to TOD we refined out our predicted landing weight and entered this on the approach ref page of the FMC - based on the landing conditions, we nominated a certain landing flap setting (landing flaps are normally only Flap 15, 30, or 40) A quick note on landing flap selection, and this can certainly vary from company to company. Some companies seem to view Flap 40 as the spawn of the devil, and to be avoided unless doom is imminent (or so I've heard), some companies prefer Flap 30 but 40 is still ok, and some prefer Flap 40 but 30 is still ok. We're pretty easy, it's down to the individual. I personally land with Flap 40 in most conditions. It provides easier speed control (more drag means it's easier to slow down), the engines are easier to keep spooled up above 50% N1 (our minimum on final approach), and the aircraft will decellerate slightly better (only a fraction, but still) on the ground. Probably the biggest factor though is that the Vref speed will be several knots lower, which reduces stopping distance, and reduces the amount of energy the brakes must absorb. The downside of increased drag is worse perfomance in the event of a go-around, but only really in the single engine case - on two engines there it plenty of power for a go-around, and of course a fractionally increased fuel burn on final approach (I'm being generous here, if its an extra 10kg I'd be surprised!) I will go with a Flap 30 landing when the crosswind is greater than 10knots (the aircraft gets noticeably twitchy in roll with Flaps at 40 and it can be easy to enter a pilot induced wobble just above the ground if you start being silly with the ailerons), or when the there is a howling headwind (the wind correction factor added onto Vref means that you may end up really close to the Flap 40 limit speeds, and a gust could send you over - which results in the flaps automatically retracting to 30, see 'Flap load relief' in the manual!)