Ken.Pascoe

Does anyone know if it's possible to get a URL for the RSS feed to this forum only? The icon below gives me all of PMDG, rather than just the 777.

Howdy All I've just been advised that to date Boeing have not done the certification testing for carbon brakes retrofitted to the 737's. Enough testing was done to ensure that the unit guaranteed at least equivalent/better performance, but to save costs the full test regime was not done to produce the data. Apparently the weight reduction in the hardware involved is about 300kg. The Max on the other hand will come with carbon brakes and the full data equivalent for better landing performance - and rejected takeoff performance.

Hmmm I had thought that Carbon Brakes had better operating characteristics as well, which translated into better braking performance. It would be interesting to know if anyone has experience of a retro fit from steel to carbon and whether braking distance was affected. Ready to stand corrected ... as always ... Hmmm I had thought that Carbon Brakes had better operating characteristics as well, which translated into better braking performance. It would be interesting to know if anyone has experience of a retro fit from steel to carbon and whether braking distance was affected. Ready to stand corrected ... as always ...

Howdy All Great answer from Kyle. Regarding the reversers - remember that if you're using autobrake 2/3/4, reversers are mostly smoke and noise and give you that feeling of being part of a team - but don't make much difference in stopping distance because the autobrakes work on a deceleration rate. So using reversers shouldn't make a lot of difference to distance, just take some load off the wheel brakes. From my 777 line experience and quite a bit of 737 jumpseat time (I have no operational experience int he 737) - the 777 has great braking. Depending on the 737 (most have steel brakes?) - the Carbon Brakes in the 777 also make a significant difference. I went from the A310-300/A300-600R to the B777 many years ago and stopping performance was one of the big changes we saw. So much better in the 777. Ken

Howdy All Years ago I was an FO in Emirates and we had 200/200ER's - all with Rolls Royce Engines. We did simultaneous dual engine starts all the time. Needless to say when the GE's came along one of the changes we had to adapt to was being restricted to one at a time by the FCOM. However human beings being what we are - I can personally attest (based on several instances) that you can start both GE's at the same time, even on pretty warm days in Dubai when the density altitude is pretty high. But as as been described here - it's probably not good for engine life. The APU may be able to handle it ok, but the lower the airflow the more critical the engine start (EGT vs Rotation Speed). I haven't checked to see if PMDG models it well - but the Rollers (with it's 3 spool engines) was very much a more sedate start, feeding fuel in with increasing flow at a fairly regular rate of increase - when the GE's came along the FF went from 0 to about 500 almost instantly, with an associated bump in rotation. The GE's also generate higher vibs during the earlier part of the start cycle. During Hot/Hung starts the Rollers also required a more restricted cooldown/re-engage the start point; whereas the GE's spin for 30 seconds and the gearing kicks straight back in. We were told this was normal and expected, and subsequent operations have certainly borne that out. Ken

Howdy All It's probably not helpful, but the auto throttle behavior in this instance is correct in respect of the actual aircraft. With a single push of the TOGA switches to commence a go-around, the auto throttle THR command aims to provide enough thrust for a 2000 fpm rate of climb (usually somewhat more than that ...) - Hence THR / TOGA / TOGA and less than full GA thrust shown on the N1's. A second push gives you full Go-Around thrust hence the transition to THR REF / TOGA / TOGA. But usually the single push gives you more than most can handle, particularly if you have a early level off and any kind of complication/distraction during the missed approach - the Airline Industry is focusing on two engine go-arounds at the moment as something of a problem, see here for a quite comprehensive analysis into go-around errors. Unfortunately the traditional regulatory focus has been on single engine go-arounds, to the point where we get lots of them, but very few 2 engine go-around in training. But when the AFDS captures altitude and transitions into SPD / ??? / ALT, the auto throttle is no longer encumbered by the 2000 fpm "limit" on thrust. The auto throttles are now commanding for speed and if the aircraft is a little slow, speed will increase. This is most noticeable during manual flight when the airspeed is a little below target - but you see it during autoflight as well, particularly with early altitude captures. I recently wrote about a procedural issue we were seeing in relation to missed approaches and I think I'll add this issue as a sidebar ... Returning to the issue at hand however - I have seen some poorly handled level offs in the FSB PMDG 777, nothing quite this bad when other factors weren't involved (auto flight, not an early level off, no speed change during the capture maneuver, etc). I haven't had much time with the P3D version yet, but hopefully it's better in this area.

The warning that should activate is part of the Takeoff Configuration Warning (FCOM 15.20.10) and the message is CONFIG GEAR STEERING. From the sounds of things you should be getting the warning - it can still go off on takeoff in the aircaft even if the tiller is straight after a turn - because the rear bogies haven't yet return to center and locked position.

Good spotting. I'm going take a stab and say it's CofA annual flight testing. I used to be involved doing some of this ay my previous carrier, and functional testing of RAT deployment was on the checklist.

Bear in mind with 737/777 comparisons that if Boeing had gotten it's way - the 737-NG flight deck would be identical to the 777. However SWA - the launch customer - wouldn't buy the NG unless it had backward compatibility with the older 737s. That's probably the reason for the 737 differences, more than any lack of consistency on Boeing's part.

Far out.

Trimming is only required for a change of reference speed. If you're fully configured and on speed (Vref +5) on final when you disconnet the AP - you shouldn't need to trim thereafter.

I'll hunt it down and tidy it up first. I have also been promising a de (airline) identified copy of the P&T which I will do as well.

"... these EO SIDs are all now programmed in the FMC ..." Only if your Airline pays for it! Actually I would be interested in hearing how they work, since I've never been fortunate enough to work for an airline who codes them in. - How do you activate/execute them for an engine failure on takeoff - How does it work if your EOSID turns left straight away but the normal SID goes right? If you wouldn't mind running through a couple of scenarios, that would be fascinating. I don't supposed EOSIDs are in PMDG?

Thanks Matt. I'll bet that's even in the manual ...

Me too. Realism is great, but I just want the background noise down 50% or so. I've tried the individual FSX sound sliders to no avail.

That must be a software mod, because most 777's don't allow entry of (even to then round) decimal distances, and don't display any decimal distances, even when the distances involved (such as down an approach) are clearly decimal - the CDU displays to the nearest nm even as it is definitely working to the accurate figure. I've never understood why the difference, and since there are a couple of different types of FMC on the 737 and I wonder if entry of decimals is available on all 737's? For the most part, it makes no difference, but for me the most obvious time I want decimals in the fix page is when depicting engine out procedures.

Takeoff Performance IS required to account for Aircraft CoG. The Laptop/Server/iPad software default assumes the worst possible situation which is full forward CoG and calculates takeoff data based on this setting. This impacts not only the speeds but the available thrust derate of the maximum permissible performance limited take off weight. There is an option that airlines can purchase from Boeing called the Alternate CoG Takeoff pack, which allows the airline to nominate a fixed point along the CoG scale. My previous airline has this option ($$ thousands) and had the value set to 28%MAC. As such anytime the CoG was at 28% or greater, we used the ALTN CoG setting in the software and this allowed the software to calculate on the basis of 28% and therefore either more de-rate or allowed us to lift more weight for a fixed thrust setting. However if the CoG was <28%, we used "FULL" CoG which basically meant the software was assuming the CoG on the forward limit and no credit was given to the CoG being aft of this. The next logical step I guess would be software where you entered the actual CoG and it calculated performance based on this but to the best of my knowledge this hasn't been done. OPT (Onboard Performance Tool) is available as an iPad app from Boeing for the 737; I have heard it's coming for the 777 as well ... But I don't know whether it's accessible outside the airline environment. It's the airline infrastructure that takes on the responsibility for keeping all the airport/airline specific background data up to date on the iPad installation as well as setting the policy on the assumptions inherent in the calculation which are legion ... However returning to the CoG in the FMC and it's impact on speeds - there's not a lot of detail in the FCOM (as has been noted). However the Honeywell manuals specifies that the Stab Trim is calculated after CoG is entered; it also says that Takeoff Speeds requires Weight, OAT, Runway, Flap and Thrust - but not CG. I can only assume therefore that the FMC does not have the capability to account for CG changes in the takeoff calculation - and irrespective of what you enter, it's probably assuming the worst case full FWD CG n the calculations. The FMC calculations are quite rudimentary in any case - valid, but not optimised and don't account for terrain, and can't calculated assumed derate.

I don't think it was intentionally engaged on the ground. But having somehow engaged it - it was not immediately obvious that it was engaged (other than AP on the ASA). You can steer the tiller without impact on the rudder since the AP doesn't touch the rudder unless LAND 3 is annunciated. But eventually they worked out out and reported it (which was the right thing to do) - and Boeing put out a notice saying (the obvious) not to engage the AP on ground before takeoff, and I think eventually putting software in place to stop it happening. At least that's me recollection of the events.

The runway symbol should definitely remain on the ND even after the route completes and remains inactive in the FMC. I haven't checked this out yet in my PMDG - but I know from experience the runway symbol remains on the aircraft. Also for ccts, I teach setting the runway into the fix page (it has to be line selected from the LEGS page) with a course along the runway centerline, and a 3nm arc. The 3 mile arc gives you a 1000 ft aim point/check height as you turn onto crosswind from the 1500 ft cct. I'll dig up a document I have somewhere on doing touch and go's in the 777 we put together for the base training we did back in 2009 if that would be useful.

Good Lord - your exactly correctly. I'd clearly built and idee fixee in my mind. Next time I'll make sure I head into the FCOM before I write!

I believe it's "When all else fails ..." hence many forum posts! Also - what's a Vertical Stabilizer? Reading back through - is the EICAS message definitely "CONFIG STABLIZER" ? The FMC CoG is referenced to the MAC-TOW (Mean Aerodynamic Chord - Take Off Weight) and in normal line ops is taken directly from the load sheet provided by ground ops and fed into the FMC. From this the calculated Stab Trim Setting (for takeoff) is calculated by the FMC, and the FWD/AFT additional trim segments may or may not display on the stabilizer trim display. The CONFIG STABILIZER message comes up as part of the takeoff configuration check (thrust setting in takeoff range plus other triggers) if the stab trim is not set to within the bounds of the green segment(s). It can be a little finicky and if you're right on the edge of the segment you could generate the warning - is that what we're seeing here? Note that the CoG setting here is also used to determine your maximum altitude. If your cruise CoG is significantly different to your takeoff setting (fuel burnt off) then updating this figure to a more correct number can improve altitude capability.

Ahh - AP engage on ground. I would not have thought of that. With Autoland in place, Takeoff remains the last bastion of the pilot flying the airplane. Fortunately - for the most part - it's a case of brute force over ignorance ... You put on a phenomenal amount of power, it races down the runway, then defies all know laws and lifts off. Or is that helicopters? Also worth noting - until recently it WAS possible to engage the AP on the ground. It's specifically forbidden by Boeing, but after a couple of pilots did it and took a while to figure out what they'd done - a service bulletin came out about it. I think the ability to engage the AP on ground was taken out by AIMS update 16 earlier this year ...

That's a good technique and one used often in the aircraft. Another use for it is to force a re-calculation of VNAV descent path when you get high or low (due ATC, winds or other factors).

Also have a look at www.flight.org

Presuming we are talking about the Red Warning light in the Master Warning/Caution button directly in front on the glareshield ... There really isn't much in a 777 that generates a warning/caution light and/or sound (buzzer, horn, bell, etc) without an EICAS message. Therefore I'm wondering if it's a coding problem? My suggestion would be pausing the simulation just after takeoff and having a really good look around the panel for a secondary indication. Especially the overhead panel and the Flap/Gear/Terrain indicators. I made this diagram up a while ago for a training presentation, it gives you an idea of what starts and stops when on a takeoff in respect of the inhibits. http://www.infinidim.org/?p=2994