Just 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 ...
Jump to postSo, is there the possibility of closing those airports? Will flights to/from HNL or OGG be affected by this...delays as well? Depends on how big the plume becomes, the direction it spreadsand and how that impinges on HNL/OGG-XXX routes. ATC game-day calls, I believe. Correct me if I'm wrong, but pr...
Jump to postI don't hear as much slang from controllers, mostly from pilots. Then again, I've only flown in the US, so maybe what I consider normal is way out of ICAO spec. "Out of ICAO spec" indeed. So much this. Pretty much anywhere else in the world, standard phraseology is used almost exclusively...
Jump to postI have a question about U.S. airspace/radio procedures that has been bugging me for years. Imagine the following scenario: I am flying along in a small airplane, VFR, and receiving flight following from the appropriate ATC unit. Let's say I'm at 2,000 feet and cannot climb higher due to cloud clear...
Jump to postThe tower can be unimpressed all they want; what the pilot did in your scenario was perfectly legal. I think the broader issue is that the airspace surrounding the airport you describe is poorly designed so as to encourage pilots to cram themselves in to a small area of the sky. Perhaps the Class D...
Jump to postBut for Charlie and Delta, you must contact ATC, but you can still enter the airspace unless they explicitly tell you to stay outside. Have I understood that correct? N1120A is correct, there is one nuance of US ATC and it comes down to grammar though too. The regulation to enter C and D is 2 way r...
Jump to postNo one seriously expected Burlington VT - Marseille direct when talking about more point-to-point routes. What *was* being referred to was a trip that used to require Burlington - JFK - CDG - Marseille to become Burlington- JFK - Marseille, with the second hub stop removed, and indeed that JFK - Ma...
Jump to postSeveral types have different door options to accommodate different densities. A330/340-200/300: big or small door 3. Same idea as the TriStar, which I hadn't known about. 757-200: 8-door and 6-door options. The 8-door gave a higher exit limit, but took up more cabin space, so many lower-density carr...
Jump to postI bet the NDB options are kept around for Air Canada, cause Canada still keeps a few NDB approaches around for no apparent reason lol A quick glance through my EFB/iPad and I don’t see any NDB approaches. It’s been years since I’ve even done one. We don’t do Range approaches either. ;) I can’t even...
Jump to postYou got a couple of the big ones already. It might help to think about what is in higher demand when overall demand drops, or what substitute goods people buy in a recession. A lot depends on the nature of the recession and what caused it. Couple trees to bark up: If it's high oil prices/oil shocks,...
Jump to postGalaxyFlyer wrote: HDG knob has “push to sync” there for a reason. Push, then select HDG mode. I guess all planes have their traps, but I never got that "feature" on Boeing. Is there any reason the heading bug isn't automatically to the current heading while in LNAV? On Airbus, the headin...
Jump to postGalaxyFlyer wrote:HDG knob has “push to sync” there for a reason. Push, then select HDG mode.
Go backseat a few IFR flight lessons at your local flight school and you'll see it in action. Student gets a bit flustered and punches AP, alt, and heading, not realizing that the bug is pointing somewhere else.... That's why the sequence needs to be: 1. FD on 2. Select modes 3. Point and read out m...
Jump to postI think I read the 747-400 had over 1,500 different customer options, from cabin fittings to the manufacturer of the Hyd pumps. With the 787 they have tried to standardize things a lot more. The book "Legend and Legacy" has a writeup of how that slowed down production. I think the example...
Jump to postYeah, that looks like the end of the road. That plane looked great in the Air Tahiti Nui scheme.
Jump to postWho are going to believe, scientific engineering data or your lying ears? Thanks guys for all the info. I do trust my ears but I trust science too, so out of pure curiosity how would you load/prep say an A333 and a B77W, let them take off within 3 minutes (implies same weather), on the same track, ...
Jump to postYeah, I heard them on the radio, they said they had an engine stall. The smell was probably smoke, the winds were blowing it back north again, it got thicker at 3000 feet.
Jump to postBy my count, that gives 5 different 330/340 fin setups, in chronological order: Early 333/342/343 fin with small angular fairing (same shape as A300/310 fin) Early 332 tall fin (height extension to existing) with big fairing (l/n 182) Late 333/342/343 fin with larger fairing (l/n 182+) A345/345 fin...
Jump to postThis article should help with a lot of the questions: https://airlinercafe.com/aviation-artic ... de-178167/
Jump to postLow RPM, I agree with, but Lycoming and Continental compression ratios are nothing to be excited about—7:1 to 9:1 typically. Any car today with electronic controls is much higher—11:1 often. Brake Mean Effective Pressure (BMEP) might be a difference in the two applications. The lack of approved ele...
Jump to postSince 2004 1700 E-Jets have been delivered. The E2 is quite a change from the E-Jet (redesigned wing, new engines and pylons, landing gear, horizontal stabilizers, a lot of systems and especially the FBW); basically, the fuselage remains and most everything else was changed. That's a bigger redesig...
Jump to postI'm not familiar with the avionics in the PC-24, but if they're solid-state piezo-electric gyros then they should be able to align within about 10-30 seconds. That means that engine start is probably your long tent pole, my guess is 1-2 minutes minimum for the FJ44, though I have no experience with ...
Jump to postIt is standard procedure to reduce flaps to an "approach" setting (which is typically also an approved takeoff setting) when commanding a go around, but with all engines operating the airplane will climb just fine with landing flaps extended. I'm pretty sure it's a certification requireme...
Jump to postHa! Yes, I am doing that exactly. That's because the only way to sell an SST is speed. Anything that slows it down hurts its business. The Concorde archives now available at BA and Air France make that clear, by the way. (Passenger surveys, etc...) And no, few US airports have fast train links into...
Jump to postPeople will go for faster planes if they are around, maybe not in a country that is close to others, but when any trip abroad is a 12 hour flight, then faster planes are very welcome. That said, the range works to be about 7800km, which is not that much further than Concorde could do. A longer rang...
Jump to postHow much extra are you prepared to pay for a faster flight? I suspect most people would be the opposite - prepared to endure longer (slower) flights if the price was lower. More than you might expect. You might be surprised at how many people from my country would be willing to spend more for faste...
Jump to postLookin at the Boom website is interesting... https://boomsupersonic.com/overture 600+ profitable routes? The only potential things I can see are TATL routes. With the 4250nm published range, there aren't many options out of LAX/SFO. http://www.gcmap.com/mapui?R=4250nm%40LAX http://www.gcmap.com/map...
Jump to postDeparture Attain as much altitude as possible before reaching residential areas. Use full length of runway when able. I don't understand. Why would a pilot " use full length of runway when able " [that's one heck of a derate!] if trying to " attain as much altitude as possible before...
Jump to postOn a side note, maybe you knew, maybe you didn't.... It's funny how the alternate fuel is calculated. Most operators will surely draw a SID from the planned destination, then a routing and then a STAR to the alternate airport for fuel calculation. So far so logical. EASA however nowhere describes t...
Jump to postThanks for the correction. I'd forgotten that the weight has not actually increased! That said, I would not totally be surprised to see a slight increase down the line, as well as a thrust bump on the engines. It is a pity they have not released any more concrete performance data gained during test...
Jump to postIt would be interesting to see some side by side photos of the different tail heights. Is it even noticeable in reality or is it just a technical specification that can't really be seen? I can definitely see it. From the other thread, these two pictures illustrate it well: 862921,1063253 The top ch...
Jump to postI don't think any were converted. Regarding the fin base fairing, the other thread got that one a bit wrong. The A332 (l/n 182 IINM, introduced the wider, smoother-bulged fin base fairing for the larger actuator, and it then became standard on the 333, 342 (the very last one) and 343 thereafter, as ...
Jump to postThere are several types that have options as well. Couple examples: 1. Most DC-9s had a smaller R1, but a larger R1 was an option. 2. Boeing 720s, DC-9-10s, and A319 optionally had one or two overwings 3. A330/340 200/300 have the option of a small or big door 3. The tradeoff is weight vs max exit ...
Jump to postIt's an aluminum powder in a clear carrier to prevent corrosion. It's rough surface is why the color looks different: https://airlinercafe.com/aviation-articles/the-true-color-of-coroguard-76412/ It gets redone at some repaints, though many carriers are getting rid of it in favor of gray paint that ...
Jump to postThere are several types that have options as well. Couple examples: 1. Most DC-9s had a smaller R1, but a larger R1 was an option. 2. Boeing 720s, DC-9-10s, and A319 optionally had one or two overwings 3. A330/340 200/300 have the option of a small or big door 3. The tradeoff is weight vs max exit c...
Jump to postI am all for mandating minimum requirements in regards to pitch/width. There has to be some limitations on what airlines can get away with in terms of safety, if nothing else. As someone who is 6'6", why should I have to buy economy plus, business or first class to be able to sit properly in a...
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