Driverab330

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  1. The first part of Second Video I posted explained why temperature has an effect on VNAV PATH. Basically the 777 VNAV system uses something called Baro-VNAV. The FMC computes a path from a point 50ft over the runway waypoint (which is the threshold) backwards to the FAF assuming the ISA weather condition (15 deg C on the ground with a standard lapse rate), and VNAV solely depends on the altimeter reading. (unlike the G/S of and ILS which defined a fix geographical path independent of the altitmeter, hence it is called a precision approach) in on a cold day, the air is more dense, and the altimeter reading is pressure sensitive so 100ft change in altimeter reading only results in let say 80ft of change in real (True) altitude. And the opposite applies in a hot day. Therefore in real life, for the same approach let say the RNP Z 07R appr into HKG which we normally do during early morning arrival, it is very common to see 3 whites on the PAPI when visual when the temp is 25c or above. Put it simply, just fly it like any other non precision approaches using LNAV VNAV PATH, I think it is good enough as a normal simmer. To be able to qualify as a pilot to do the RNP / RNP AR APPR requires at least one simulator exercise and one simulator check as part of our bi-annual proficiency check. And before that a self-study PowerPoint package which takes about 3 hours to complete. It is is never an easy topic to be able to explain with one to two hundreds words here in a forum. I am sure those who have flown the 777 RNP approach in various airports around the world real life, RNP AR APPR is not as accurately as it “depicts” on the charts becuase it is still largely subjected to a temperature issue which requires quite a bit of correction at minima, and it is also very common to see the airplane not quite line up the rwy as well. I have yet to try the RNP AR APPR WITH LPV minima on the A350. I Will definitely see how it work in about 1 year time.
  2. What you need is an onboard GPS and position monitoring system. And during the approach make sure there is no NAV UNABLE RNP, POSITION DISAGREE MSGS. Other than that you just need to trust the system and manage your speed in accordance to the approach chart. Most importantly, only select the RNP (RNAV) approach from the FMC database. I recommend reading the FCOM3 which has a very detailed MCP altitude setting procedure involving all the non precision approaches using VNAV. The only problem in real life is that the VNAV PATH assume ISA temp deviation, therefore will resulted in steeper descent path in a hot day and a shallower descent path in a cold day. Thats why there is a temp limit to all the RNP (RNAV) approaches to ensure terrain clearance in a cold day with a shallower descent path. And to some places like dubai, to ensure the descent angle in a hot day does not exceed aircraft limit. I agree with all the comments above, it is easier to understand how RNP approaches works with IAN because it works like an ILS at the beginning. IAN approach is the equivalent of the FINAL APP mode on the Airbus where the airplane follows the LNAV VNAV PATH as if it is flying an ILS app. like Airbus, once FINAL APP is engaged, one may set Miss Approach Altitude straight away. (See the airbus video below and see how FINAL APP work which has pretty much the same logic as IAN) Since the 777 does not have IAN, there is a complicated MCP altitude setting procedure to follow. The way I see it, it is no different to doing an VOR approaches on the 777, just keep everything in LNAV and VNAV PATH, and disconnect the AP when you can see the rwy. The only thing is there is no ground nav aid for you to reference to on the RNP approach. https://www.youtube.com/watch?v=6r7QsQ6WHbA I found two youtube video which may help understanding the theory and actual practical application behind the RNP approaches (RNAV approaches). https://www.icao.int/MID/Documents/2016/PBN SG2/2.PBN Charting - ICAO.pdf also the ICAO recommendation is to rename all RNAV (GPS / GNSS) app to RNP approach and what we used to called RNAV (RNP) APP into RNP (AR) APP which AR stands for Authroization Required.
  3. If the PFD says NO AUTOLAND and the pitch mode did not change to FLARE, you did the flare manually.
  4. The airplane itself does not know whether the airport ILS system is CAT 1 / 2 /3A /3B /3C. This has to do with the integrity of the ILS signal and other ground related systems i.e back up power to the ILS, LVP approach and runway lightings etc. as long as you have at least LAND 2 showing in either one of the PFD, you may perform an auto land in any ILS approach. In fact, an CAT 1 minimum or above auto land is quite often performed in real life. However, some airline may have an in-house approval process to those CAT 1 only runways, for example an real auto land have to been successfully performed for a number of times by check and training captain in day VMC in order to verified the autoland performance to such runway. Some runway with unusual slope may affected the ability for the airplane to conduct an autoland. For example. FAOR (Johannesburg) runway 03R, the Airbus A340 could not perform an autoland. But the Boeing’s are ok. The 777 autoland is terrific. The video below shows a cx 777-300 performing an autoland. The cross wind was 25G35kts that day. (A friend of mine was flying on this particular flight)
  5. Yes. If the landing is too smooth the Weight on Wheel sensor wouldn’t reconginze the landing until a later time. Because on the 777 the Weight on Wheel sensor is located at the Therefore the spoilers won’t deploy immediately after touchdown. Because pilots don’t look at the speed brake lever during landing, so we pull the reverse when we can feel that little “bump” and begin to lower the nose. Therefore in this case the spoiler will deploy as reverse is pulled. And we will get the A/T disconnect EICAS msg. The danger is is of course you don’t even feel that little “bump” and keep flying at a fixed pitch attitude until the Wing loss enough lift eventually to let the airplane sit on its wheels, in this scenario you would have lost quite a bit of braking distance. In the two extreme between “you have got to dump it on the ground” and “you need a silky smooth one”, my belief is that there is got to be a happy middle point, and a good pilot is able to adjust this in accordance changing wx condition. Again, if the technique is right and one is aimming for the right touch down point. You won’t be far off. And I doubt that anyone would be staring at the VSI during the flare either, because it won’t show you an accurately value below +/-400fpm.
  6. You are right. The nose wouldn’t drop in both airbus and 777 because of the FBW system, but you still need to pitch up slightly in turn to maintain altitude like a conventional airplane, all the FBW does is it maintain a stable attitude in turn so that pilots do not need to apply constant back pressure on the yoke or side stick. If you simply roll airplane without any pitch input the airplane would deccent at about 100fpm depends on AOB. The PMDG 777 in for some reason does require a much larger pitch change than the real airplane in turn especially with AOB >20deg. For example a level turn with F5 out 180kts you will need almost 10deg nose up to maintain level flight without losin altitude. In contrast a normal straight and level flight for the same pitch and speed is about 5-6deg nose up. On the real airplane for any turn with AOB below 30deg all you need is ~ 1 deg pitch up at max. With N1 incense by 5% most of the time.
  7. Yes the airbus has a higher pitch attitude on approach ~4deg and touch down at 6deg. That’s why it feels weird at first when you can see lots of ground on approach. when I first fly the 777 I tend to pitch up a lot for that particular reason. Have a good weekend
  8. You are welcome if you are able to apply the same technique consistently, you should be able to get the same result within a range every single time. It is almost like if you set 85-88% N1 and 2.5 deg pitch up at cruise altitude, the speed will be roughly M0.83. Just remember there are 3 major elements that controls your landing accuracy. 1 ) your Flare height 2 ) how fast do you reduce your thrust to idle and / or when (i.e by default A/T begin to reduce the thrust to idle at 20ft RA, you can vary depending on weather condition and the approach geometry) 3) the rate of your pitch up movement during flare. Is it a slow and smooth flare or is it just one prompt flare. (Different people have adopt different style, some may prefer a slow one and begin the flare a bit higher and others may prefer a prompt flare at a lower flare height) After a while you will know how to make small adjustment during the flare to perfect your landing technique. Initially for practice, I recommend trying a lighter weight (or give yourself some steady 10kts headwind) to have an approach speed of around 140-145kts. This way it slows things down a lot and you wouldn’t get a “rush towards the ground” feeling at 50ft callout and panic - ( This is a very common problem for new guys who come over from the airbus, because the airbus flies 10-20kts slower on approach.) The rest is just practice. Have fun.
  9. Anything below 3ft per sec (180ft per min) on the 300ER can be felt as a “smooth” landing from people inside the airplane. If the technique is correct, usually you aim to touch down between 1000-2000ft from the runway threshold with a sink rate ~120ft per min. And this will be really smooth. I personally do not encourage attempting to make super smooth landing on any wide body airplane for the following reasons: 1) it increases the chance of a late touch down which increase the chance of runway excursion. Becuase excess margin between the required landing distance and the runway length available isn’t much. Especially going to JFK runway 22L, quite often our 773ER only has about 1000-1500ft margin left. Considering the airplane travels about 150-200ft per second, if you float about extra 5 seconds that’s it. 2) by holding the nose off and continuing to pitch up like flying a C172 will increase the chance of Tail strike especially on the 300ER. Although the 773ER still has quite a lot of margin on landing before one can scratch the tail, yet it is a good technique to refrain keep raising the nose on landing when flying big jet, whether it is Boeing or Airbus. The autopilot makes a good landing. The best way to learn is to learn from the autopilot. By performing an autoland and look outside and see how the visual picture changes. In short, the recommended landing technique for the 773ER (from my company FCTM) is have your aiming point fixed on the 1000ft marker of the runway (usually the 2nd set of marker from the threshold). keep that visual aiming point at a constant position such that if you don’t flare you will crash into it. Hold it until you hear the 40ft call out. Then gently raise the nose up. You may try to look at the far end of the runway at this point to gauge the sinkrate of the airplane, keep the airplane going down by not over flare too much. **To myself I simply change my aimming point from the 1000ft marker to the 2000ft marker (the forth set of marker), so that as long as I touch down and still have the 2000ft market in sight, my main gears will touch down approximately 1500ft down the runway, this will also help if you only have 1.5-2.0km visibility and you can’t see the end of the runway, at least you will know where you are on the runway by looking at th markings. The pitch attitude At the touch if done correctly should be about 2.0-3.0 deg depends on the approach attitude. (Usually the approach pitch attitude + 2 deg)
  10. Great video indeed!! Small things about the Flap retraction. I saw you waited until F5 speed before you raise the Flap from 15 to 5. this is too a 747-400 practice as well. On the 777 (same as airbus) as long as you are above F15 speed and accelerating (either you have a trend arrow or the number is moving up), you can select F5. And so forth for the rest of the Flap retraction. Becuase the (as per FCTM which has two charts on maneuvering margin, one for Flap retraction and the other for Flap extension ) the 777 has sufficient maneovring margin during Flap retraction. Happy Holidays everyone.
  11. Good to know, thx for the link. But it is not for long, 5 Cathay ones will be leaving the fleet (most likely will be scrapped except LN1 which is B-HNL) in 2018.
  12. I sincerely hope PMDG would make the original 777-200. The airplane which completed the first flight will be retired in the middle of 2018 and returned to Boeing. I am not sure how many original 777-200 (not the 200ER) are still around, I would anssume the aren’t that many of them still flying.
  13. Gentlemen, if you want to try something different and wish see more than one sunrise in one single flight, I suggest you try to simulate CX845 KJFK to VHHH in summer time over the pole. Alternatively CX899 from EWR to VHHH will also work. This particular flight departs after midnight out of JFK. The sun rises two hours into the flight. Just after you cross the pole the sun goes down again. In summer time you will see the sun rises again just before landing into Hong Kong at around 5:30am local time. The flying time usually sits around 15:30hr, it is like doing a round trip flight from Brisbane to Hong Kong and back to Brisbane in one go.
  14. It is designed to be hand flown as well, but since a lot of times the VNAV on the real airplane will overshoot 10-30ft on altitude capture any way, as a good pilot if you to want fly accurately in altitude you will inevitably have to be “leading” the flight director in pitch mode a bit by reference to raw data, this will come by with some experience to, if done perfectly it will look like you are closely follow the FD but in effect it was the FD following you in pitch mode. for example once you get SPD VNAV path / VNAV ALT / ALT, you may pitch down slightly lower to get a lower V/S first. Because sometimes the FD will not command a level until you are 90ft from the target altitude while still doing 1000ft/min Rate or climb or descend. In that case if you are following the FD, there will be some delay between the actual FD command level and your control input, and further delay until the airplane actually respond to your control input. Therefore in in the case you are almost bound to overshoot the target altitude, especially with a high rate of climb of 2000-3000ft/min. In this case, if you prefer to hand fly, just pitch down using raw date as you arppaoch your target altitude but wait until the mode changes from “THR REF VNAV SPD” to “SPD VNAV PATH or VNAV ALT or ALT”. It is because you don’t want to pitch down too early with the Autothrottle still commanding CLB thrust, otherwise the speed will go up. Once the A/T mode changes to speed, your speed is being look after, then it will be ok to depart from the pitch of the FD a little bit to anticipate the level off. To practice just flying a few raw data climb or descend to a level off just like a IFR student pilot, you will get a feel of it. The 10% rule usually work (I.e for a 1000ft/Min rate of climb or descend, begin to level off 100ft before target altitude), may be allow 50ft more initially for a smooth level off to impress the passengers. For the 777 if you really want the pax to feel nothing, at 2000ft/min rate of climb you should begin your level off smoothly and slowly at around 300ft below / above target altitude and to reduce the vertical speed to 1000ft/Min approaching 100ft before target then apply the above technique. After some practice it will be one very nice smooth continuous action, even better than the autopilot.
  15. When one takes into account the airport elevation of KLAS is ~2181ft, an level off altitude of 7000ft only means there is just 5000ft of climb for the airplane to go before ALT capture. Having recently did a real ferry flight on the 773ER at 186tons take off (But the 772LR at the ferry flight weight will be even lighter with lower empty weight than the 773ER), I am quite happy to share some thoughts about this. With the AP engage, for an altitude about 7000ft (in your case just 5000ft AGL), it is less likely for the VNAV to overshoot because it will transition to Altitude capture mode at around 4000 to 5000ft and then the AP will slowly pitch down to level off. The pitch control of the AP on the real airplane is very slow to respond and it is tuned for passenger comfort, it is therefore quite common for an altitude bust if you have a low initial level off altitude like 2000-3000ft (normally the AP overshoots by about 200ft in most cases, but still within the IFR limit of 300ft) because you would still have the TO thrust until at least 1000ft AAL and by the time you select Flap 1 for CLB thrust to be selected you will be close to 2000ft already, although by then the mode would have changed to SPD VNAV ALT (or PATH depends on the coding) The other interesting note is that with TO2-56 Take off thrust, on the 773ER, the thrust provided by CLB-2 is actually higher than the Take off thrust. So you will see your Rate Of Climb to trend up after CLb 2 is set. The rate of climb for a ferry flight weight (186TONS take off with ~175tons empty weight) 773ER before Thrust reduction was about 3200ft/Min and after clb2 is set it went to 3600-3900ft/min. Compared to a normal Rate of climb which is about 2000-2500ft after take off and around 1500-2200ft after thrust reduction. For my ferry flight, I managed to hand fly the airplane to about 15000ft staying in VNAV mode most of the time except two occasions. There was an ATC intermediate altitude restriction of 9000ft over a waypoint, as I approached about 6000ft I asked PM for V/S +1000(As other had previously suggested above). That way it slow things down dramatically and allows you to relax. The other trick (if you are doing it outside USA) is to request high speed after airborne. So once you clean up and above the MSA and terrain is not a problem just wind the speed up to 320kts, this will also slows down the rate of climb as well, couple with active use of V/S mode to manage the climb. I would still recommend to use the above technique even with the autopilot engaged. It just makes the life a a bit easier, as normal line pilot don’t really get to see this type of sporty action from the airplane that often. In addition, sometimes ATC will also get nervous as they see you zooming up on the radar if they have a quite few over fly traffic the area. The worse is not a ferry flight. The worst is that you have to go a full TO thrust take off out of an airport with F20 at 210tons on a normal passenger flight (like an 1:20hr trip from Tai pei to Hong Kong) because someone reported a windshear event on departure. You get airborne, already climbing like a rocket and found out that the windshear was +20kts.... and now because the PM couldnt get a word in with the departure controller because the frequency is so busy, you need to level off at 3000ft as required by the SID. In this case I just use the Autopilot straight away at 200ft. There are days when there are so many threats to deal with and it is just not worth “flying” the airplane at all.