On shorter models in a family it also helps with Vmc. As your rudder lever arm gets shorter, you lose yaw authority, so you need a corresponding reduction in thrust.
Jump to postThe second numbers are the engine OEM, and the third is the engine subtype or thrust plug. In many cases, it's physically the same engine, just a different rating. A319: 112/111/114/115: CFM56-5A vs 5B: the 5B is slightly longer and has an extra compressor stage. More here: https://en.wikipedia.org/...
Jump to postThe other problem you have with too long is the fuselage becomes inefficient; the A340-600 suffered a bit from this, it was just too long for 8-abreast. 10-abreast will suffer the same issue at 80m+. What is the aerodynamic science behind that? How is the A321 or 753 different? It's a structural th...
Jump to postAre commercial airline pilots the highest paid profession in the US? I would say no, but that depends on a lot of definitions. First of all, how do you define "commercial airline pilot"? If, like much of the uninformed public, you only count the Big 3 as "real" airline pilots*, ...
Jump to postRegardless of the lighting, you're not allowed to take off until the RWSL is off AND you get cleared. That said, it should probably wait until the other aircraft is clear.
More info:
https://www.faa.gov/air_traffic/technology/rwsl
There's a few old threads on this. If you look at the wingtip, the end is pretty tapered and the aft end does go further out than the front tip does, so one could argue that it's just less raked than the 200LR/F/300ER wing. Keep in mind that the canted winglet designs were all featured on types that...
Jump to postLooks like Airbus is basically doing the same Dial-a-flap concept that MDD used, except they've obfuscated the details from the pilots a bit to make it simpler. Boeing just has more flap settings (e.g. 10, 13, 15, 17, 22, etc.) and then the performance calcs figure out which one to pick. I suppose t...
Jump to postWhere can I learn more about the 77W’s wings being “too small?” What makes them too small? Self gloss here but I did quite an involved thread on exactly this a few years back. I think its still relevant and might be worth a read. https://www.airliners.net/forum/viewtopic.php?t=1426609 The wing area...
Jump to postImagine an A340 equipped with PW1100G GTF's, and the attendant ~20% fuel burn decrease! There was a what-if thread about that a few years ago. I think the consensus was that you'd have too much range at MZFW. You'd have about the same MTOW as a 359 on a smaller frame with less capacity. Against a 7...
Jump to postIt would be for for a paper A330 with the MTOW of the A340 or greater (~295t) to support longer range and A330-400 back in the late 90's before the A330 gained the range it has today. The figures I'm getting from wikipeida for engine weights are: Trent 700: 6.16t Trent 7000: 6.45t (just for compari...
Jump to postI don't know if CFM was ever exclusive on the 200/300, that's a good question. IAE probably could have done something similar to CFM in putting a bigger fan and another LPT on there to spin it. From what I've read about the V2500 vs CFM56, the former is typically more efficient on longer sectors du...
Jump to postI don't know if CFM was ever exclusive on the 200/300, that's a good question. IAE probably could have done something similar to CFM in putting a bigger fan and another LPT on there to spin it. From what I've read about the V2500 vs CFM56, the former is typically more efficient on longer sectors due...
Jump to postThat doesn't make a lot of sense. The 350 and 330 have much less in common than do the 330/340. It comes down to pilot type rating requirements, a pilot on a 330/350 needs to demonstrate the ability to land with one engine out. Where a pilot on a 340/380 needs to be able to land with 2 engines out....
Jump to postStarlionblue wrote:For reasons that are not quite clear to me, A330 and A340 are mixed fleet, not common type, while A330 and A350 are common type (in many jurisdictions).
If you've not yet read Norris and Wagner's book "A340 and A330," I highly recommend it. Many of those questions are addressed in the R&D phase. The PW2000 and RB211-535 were considered and rejected because they were too big and heavy and would have been running at partial power too muc...
Jump to postI think you mostly answered your own question with a "yes." Over time, planes gain weight from skin patches, dirt, and pens that pilots drop through gaps in the floor. Likewise, engines wear out and lose efficiency. Specifically to the 777-300ER, there are a few changes that make the newer...
Jump to postNo one cared about non smokers, unfortunately. No matter where smokers were placed, it was awful. How I do remember! It was horrible. I remember staying in the lav longer then necessary just to breathe some reasonably cleaner air. You'd get off of the plane smelling like an ashtray and the first th...
Jump to postIf you want to make the airplanes more efficient, you're probably better off increasing the takeoff roll. Many engines are sized for OEI thrust and climb gradients, so if you double the length of every runway out there you can get away with smaller engines, which will then weigh less and consequent...
Jump to postTheoretically you could get an STC for that, but it'd probably add structural weight and might not pencil out. In practice, the juice isn't worth the squeeze.
Jump to postIf you want to make the airplanes more efficient, you're probably better off increasing the takeoff roll. Many engines are sized for OEI thrust and climb gradients, so if you double the length of every runway out there you can get away with smaller engines, which will then weigh less and consequentl...
Jump to postI'm pretty sure that the NG scimitar winglet uses the original blended winglet and adds the lower portion as well as a new upper tip. http://www.b737.org.uk/latest-2015-08-08.htm As far as the retrofits to the 900s, I think there are two groups of wings: 1. The early wings needed more reinforcement ...
Jump to postThe Americans who have a passport and are comfortable traveling have become so used to everything being at panic level orange or red for the last several decades that it gets ignored. I've seen some pretty laughable advisories go out.
Jump to postWhen launching the 320neo, John Leahy said something to the effect of "you can get 20% spending 10B on a new frame, or you can get 15% on new engines spending 1B on a re-engine, so that's what we'll do and B will eventually follow." That's almost exactly what happened. These days it might ...
Jump to postNot sure if this was already brought up: international-to-domestic transfers at almost any US airport. Going through immigration, baggage claim, customs, recheck, and security is usually an awful passenger experience. CBP already has the authority to look at whatever they want without the passenger...
Jump to postNot sure if this was already brought up: international-to-domestic transfers at almost any US airport. Going through immigration, baggage claim, customs, recheck, and security is usually an awful passenger experience. CBP already has the authority to look at whatever they want without the passenger ...
Jump to postCouple that I can think of that I use regularly: Wind correction is 60/TAS * crosswind component Target sink rate is GS * 5 on a 3-degree glide path Outbound holding correction on a 1-minute hold is 200/TAS seconds/kt for HW and 300/TAS seconds for TW (Garmin boxes are not very good at this) I've a...
Jump to postCouple that I can think of that I use regularly:
Wind correction is 60/TAS * crosswind component
Target sink rate is GS * 5 on a 3-degree glide path
Outbound holding correction on a 1-minute hold is 200/TAS seconds/kt for HW and 300/TAS seconds for TW (Garmin boxes are not very good at this)
The change in lateral lift distribution doesn't make much of a difference in stress on the wing. As to why crews level off and then keep going down with the boards out, it's usually a combination of speed restrictions on the STAR or a speed limit (e.g. 250 under 10k in the US) and needing to bleed e...
Jump to postI just don't see why I should be partaking in an event that clashes with something that is more directly important to my career. So, I'm pretty confused on what I should do, so I'll attempt to keep all options open. Thanks in advance. I think you answered your own question. You've got 168 hours in ...
Jump to postProbability of being lazed is higher than getting shot at. Lots of people pointing laser pointers at airplanes all of the time… The last time I got lased, after making the report to ATC, I wanted to see what happened when I turned off all of the lights. the Laser “went” away as in it wasn’t shining...
Jump to postBlaming the ATP rule ignores the effects of the age 65 rule (stagnated seniority meaning many RJ pilots left); the economy after 2009 (little hir8ngm some furloughs); COVID (huge bulge of voluntary or early ot retirements); the 2-years of planes and crews going non-current generating bulge in train...
Jump to postI recommend against doing too much sim flying. It's fine for learning procedures and running checklists if the panel is a close match to the plane, but outside of that the lack of tactile feedback will make it tempting to fixate on instruments and you'll get jerkier inputs. If you catch yourself doi...
Jump to postFair enough, I suppose it's still better to have a grasp of those things so that you can apply the TLAR and TARA principles when operating.
Jump to postJust like in the rest of the world, then. ;) Like many of my colleagues, I went straight from 172s to A330s, and with far fewer than 500 hours. I had a "frozen ATPL", meaning I had passed the exams, but didn't yet have the required experience for the ATPL to be issued. Once I had said exp...
Jump to postMy assumption is they're primarily doing that for the military folks, at this point. There are no military pilots clamoring to fly for my ULCC These are all 23-24 year old pilots who have come straight from flight instructing and going from Senecas and 172s going right into 320s/321s Just like in t...
Jump to postJust remember a “derate” is like putting a different thrust engine rating on the plane, “Reduced” is the engine’s thrust rating reduced due to conditions, but full rated thrust is there. A key point. And an important one to bring up during the departure briefing. If you're using a derate you specif...
Jump to postFrom what I have heard, the A340 engines would regularly overtemp EGT if it was hot and/or high, and require thrust reduction. :) Regularly is a bit too much of a word. But with high OAT and TOGA-takeoff, the possibility of an EGT exceedance during takeoff or shortly afterwards is higher. The reaso...
Jump to postMost Boeing models have two catalog options. The climb derates either wash out between 10-12K or 10-30K. What are actual derate parameters? Something internal to engine like N1, fuel flow, temperature? Or engine actually gets altitude information and thrust is limited according to preprogrammed for...
Jump to postSchedules will always fluctuate with trends in demand, but where an airline says something like ‘if we hire 10,000 staff in two months and have zero attrition then we could staff our entire schedule,’ that’s clearly unrealistic. An extreme example, but that’s basically the point Kirby was making. W...
Jump to postThere's a thread somewhere about derates on here. Most of them wash out in the 8-10k foot range and then resume the normal climb schedule. I'm pretty sure that only applies to the dense air conditions where it gets the most strain. Higher up you want to allow higher settings because the engine is mo...
Jump to postLift scales as the square of TAS. That means that if weight increases, TAS must increase as sqrt(weight). To get to that TAS, many stretches/HGW have more powerful engines, or accept longer rolls. Structurally, heavier variants often have the same geometry, but different thicknesses (e.g. 737-700 vs...
Jump to postWill the term “high latitude flights” work for pendants? *pedants... Sorry, I had to :D High reindeer traffic during this time of year with no transponders due to the chip shortage.... This answer is a winner. Maybe they didn't have the latest ADS-B update, so we can't see Santa on the fishfinder.....
Jump to postWell one quick way to control for image distortion is to look at another one: 6693295 Looks like others have that same setup as well. My completely uneducated guess is that they stretched the Trident 3 in that area, and wanted to shoehorn windows in. They may have had irregular frame spacing in that...
Jump to postAs a first-order approximation, thrust scales as the square of N1. If you spin a fan blade at twice the speed, it'll travel through twice the molecules (2m) and accelerate them to twice the speed (2a), so you end up with 4F=2m*2a. This obviously ignores the core flow, blade flex, thrust lapse, etc....
Jump to postYes, the GE90-77/90 is substantially larger. The fan diameters are 110" (T800), 112" (PW4070-4090), and 123" (GE90-77/90). The GE90 looks visually bigger to me, the pylon goes up and forward a substantial amount to go over the larger diameter. Also the bypass duct looks visually large...
Jump to postHere's an article on the fuel safety piece: tl;dr H2 is not worse than Jet A: https://leehamnews.com/2020/08/14/bjorns-corner-the-challenges-of-hydrogen-part-4-hydrogen-safety/ The Challenger blew up because the SRB O-rings leaked and the launch team ignored Roger Boisjoly, nothing wrong with the H2...
Jump to postI'll add that with a tailwind or crossind above 20 knots, the A350 thrust setting procedure is bit more involved. - Initially move the thrust levers from idle to the position that gives 25% thrust*. - Once thrust is stabilised, progressively move the thrust levers to reach the following: --- At 20 ...
Jump to postIn the US, 250/10,000’ is pretty hard limit, ATC cannot approve “high speed” like they can in other parts of the world. It has been accepted that heavies, esp 747 and 777, can climb at the lowest IAS for the clean configuration, often about 280, BUT, the FAA General Counsel did publish a ruling sta...
Jump to postBy the way, is it correct that the 747 has got the same tires on main gear and nose gear? It's true for most, but not all of them. The 747-100 had the same tires as the 707-320B (IIRC Pan Am wanted them to be swappable), then they grew. The 748 has a slightly smaller nose tire than mains: Here's a ...
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