Search found 2643 matches

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by LH707330
Mon Jan 30, 2023 1:24 am
Forum: Technical/Operations
Topic: Engine Derates and top-of-climb power
Replies: 80
Views: 4309

Re: Engine Derates and top-of-climb power

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...

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by LH707330
Sat Jan 28, 2023 3:21 am
Forum: Technical/Operations
Topic: Engine Derates and top-of-climb power
Replies: 80
Views: 4309

Re: Engine Derates and top-of-climb power

From 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...

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by LH707330
Wed Jan 25, 2023 5:31 am
Forum: Technical/Operations
Topic: Engine Derates and top-of-climb power
Replies: 80
Views: 4309

Re: Engine Derates and top-of-climb power

Most 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...

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by LH707330
Tue Jan 24, 2023 4:39 am
Forum: Civil Aviation
Topic: US DOT Now Investigating Carriers for Selling Tickets on Phantom Flights They Don't Plan to Operate
Replies: 93
Views: 14114

Re: US DOT Now Investigating Carriers for Selling Tickets on Phantom Flights They Don't Plan to Operate

Schedules 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...

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by LH707330
Mon Jan 23, 2023 1:37 am
Forum: Technical/Operations
Topic: Engine Derates and top-of-climb power
Replies: 80
Views: 4309

Re: Engine Derates and top-of-climb power

There'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...

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by LH707330
Wed Dec 14, 2022 7:03 pm
Forum: Technical/Operations
Topic: Max wing loading (and modifications to it)
Replies: 3
Views: 894

Re: Max wing loading (and modifications to it)

Lift 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...

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by LH707330
Fri Dec 09, 2022 12:04 am
Forum: Technical/Operations
Topic: Polar Route Limitations
Replies: 29
Views: 5312

Re: Polar Route Limitations

Will 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.....

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by LH707330
Wed Dec 07, 2022 4:04 pm
Forum: Technical/Operations
Topic: Seemingly weird window pattern on the HS Trident
Replies: 4
Views: 1543

Re: Seemingly weird window pattern on the HS Trident

Well 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...

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by LH707330
Mon Dec 05, 2022 11:52 pm
Forum: Technical/Operations
Topic: Relative size B777-200 engines
Replies: 19
Views: 4297

Re: Relative size B777-200 engines

Yep. The case of the 115 is much longer though.

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by LH707330
Mon Dec 05, 2022 6:30 pm
Forum: Technical/Operations
Topic: A380-841/842 Takeoff Thrust Procedure
Replies: 17
Views: 4063

Re: A380-841/842 Takeoff Thrust Procedure

As 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....

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by LH707330
Mon Dec 05, 2022 6:19 pm
Forum: Technical/Operations
Topic: Relative size B777-200 engines
Replies: 19
Views: 4297

Re: Relative size B777-200 engines

Yes, 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...

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by LH707330
Sun Dec 04, 2022 5:01 am
Forum: Technical/Operations
Topic: Fan with electric core - possible?
Replies: 22
Views: 1622

Re: Fan with electric core - possible?

Here'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...

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by LH707330
Thu Dec 01, 2022 4:52 pm
Forum: Technical/Operations
Topic: A380-841/842 Takeoff Thrust Procedure
Replies: 17
Views: 4063

Re: A380-841/842 Takeoff Thrust Procedure

I'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 ...

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by LH707330
Thu Dec 01, 2022 4:43 pm
Forum: Technical/Operations
Topic: Singapore / Indonesia / Malaysia Airspace Speed Restrictions Under 10k Feet | Do They Exist?
Replies: 27
Views: 1621

Re: Singapore / Indonesia / Malaysia Airspace Speed Restrictions Under 10k Feet | Do They Exist?

In 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...

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by LH707330
Tue Nov 29, 2022 10:17 pm
Forum: Technical/Operations
Topic: Tyre measurements 747-400
Replies: 6
Views: 2094

Re: Tyre measurements 747-400

By 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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by LH707330
Mon Nov 28, 2022 9:58 pm
Forum: Civil Aviation
Topic: Mauna Loa Erupting on Hawaii's Big Island.
Replies: 19
Views: 4843

Re: Mauna Loa Erupting on Hawaii's Big Island.

So, 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...

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by LH707330
Wed Nov 23, 2022 3:15 pm
Forum: Technical/Operations
Topic: VFR question regarding US Airspace: Class D and Charlie
Replies: 23
Views: 1659

Re: VFR question regarding US Airspace: Class D and Charlie

I 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...

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by LH707330
Tue Nov 22, 2022 5:59 am
Forum: Technical/Operations
Topic: VFR flight following and Class D airspace
Replies: 11
Views: 1037

Re: VFR flight following and Class D airspace

I 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...

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by LH707330
Tue Nov 22, 2022 5:51 am
Forum: Technical/Operations
Topic: VFR question regarding US Airspace: Class D and Charlie
Replies: 23
Views: 1659

Re: VFR question regarding US Airspace: Class D and Charlie

The 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...

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by LH707330
Mon Nov 21, 2022 8:14 pm
Forum: Technical/Operations
Topic: VFR question regarding US Airspace: Class D and Charlie
Replies: 23
Views: 1659

Re: VFR question regarding US Airspace: Class D and Charlie

But 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...

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by LH707330
Mon Nov 21, 2022 8:04 pm
Forum: Technical/Operations
Topic: The future? Bigger jets?
Replies: 46
Views: 8371

Re: The future? Bigger jets?

No 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...

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by LH707330
Sun Nov 20, 2022 4:08 pm
Forum: Technical/Operations
Topic: Operating at exit limits
Replies: 8
Views: 1414

Re: Operating at exit limits

Several 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...

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by LH707330
Sat Nov 19, 2022 2:39 am
Forum: Technical/Operations
Topic: Boeing / Airbus - factory options?
Replies: 22
Views: 3178

Re: Boeing / Airbus - factory options?

I 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...

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by LH707330
Mon Nov 14, 2022 5:10 pm
Forum: Technical/Operations
Topic: What did well in 2008?
Replies: 9
Views: 2151

Re: What did well in 2008?

You 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,...

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by LH707330
Sun Nov 13, 2022 1:50 am
Forum: Technical/Operations
Topic: Pilot/auotopilot incedents
Replies: 24
Views: 2847

Re: Pilot/auotopilot incedents

GalaxyFlyer 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...

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by LH707330
Fri Nov 11, 2022 9:14 pm
Forum: Technical/Operations
Topic: Pilot/auotopilot incedents
Replies: 24
Views: 2847

Re: Pilot/auotopilot incedents

GalaxyFlyer wrote:
HDG knob has “push to sync” there for a reason. Push, then select HDG mode.

That, or keep it in roll/level mode until validating the input. It's fun to teach AP use in the sim because you can let the situation develop further without it becoming a safety problem. Law of intensity at work.

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by LH707330
Fri Nov 11, 2022 4:25 pm
Forum: Technical/Operations
Topic: Pilot/auotopilot incedents
Replies: 24
Views: 2847

Re: Pilot/auotopilot incedents

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...

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by LH707330
Fri Nov 11, 2022 4:08 pm
Forum: Technical/Operations
Topic: Boeing / Airbus - factory options?
Replies: 22
Views: 3178

Re: Boeing / Airbus - factory options?

I 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...

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by LH707330
Fri Oct 21, 2022 4:55 pm
Forum: Civil Aviation
Topic: Last A340-200 in commercial service apparently being parted out
Replies: 7
Views: 3134

Re: Last A340-200 in commercial service apparently being parted out

Yeah, that looks like the end of the road. That plane looked great in the Air Tahiti Nui scheme.

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by LH707330
Fri Oct 21, 2022 4:49 pm
Forum: Technical/Operations
Topic: 787 vs A330 Runway Performance/Requirements
Replies: 55
Views: 7314

Re: 787 vs A330 Runway Performance/Requirements

Who 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, ...

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by LH707330
Tue Oct 18, 2022 3:54 pm
Forum: Civil Aviation
Topic: DL20 SEA-LHR dumping fuel after take off
Replies: 36
Views: 8956

Re: DL20 SEA-LHR dumping fuel after take off

Yeah, 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.

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by LH707330
Sun Oct 16, 2022 12:31 am
Forum: Technical/Operations
Topic: "Tall Tail" A330-200s
Replies: 14
Views: 6278

Re: "Tall Tail" A330-200s

By 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...

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by LH707330
Fri Sep 30, 2022 3:09 pm
Forum: Technical/Operations
Topic: FAA approves Gami100UL for entire piston engine fleet
Replies: 39
Views: 5842

Re: FAA approves Gami100UL for entire piston engine fleet

Low 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...

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by LH707330
Fri Sep 30, 2022 2:51 pm
Forum: Civil Aviation
Topic: A220 vs E-195E2 2022 update: Market battle already won by Airbus ?
Replies: 102
Views: 20249

Re: A220 vs E-195E2 2022 update: Market battle already won by Airbus ?

Since 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...

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by LH707330
Thu Sep 29, 2022 2:22 pm
Forum: Technical/Operations
Topic: Fictional scenario PC-24 emergency take off (novel related)
Replies: 16
Views: 2738

Re: Fictional scenario PC-24 emergency take off (novel related)

I'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 ...

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by LH707330
Thu Sep 22, 2022 3:47 pm
Forum: Technical/Operations
Topic: Flaps and aborted landings/go-arounds
Replies: 18
Views: 3872

Re: Flaps and aborted landings/go-arounds

It 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...

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by LH707330
Tue Sep 13, 2022 3:01 pm
Forum: Civil Aviation
Topic: Boom Supersonic new configuration.
Replies: 349
Views: 70590

Re: Boom Supersonic new configuration.

Ha! 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...

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by LH707330
Tue Sep 13, 2022 2:47 pm
Forum: Civil Aviation
Topic: Boom Supersonic new configuration.
Replies: 349
Views: 70590

Re: Boom Supersonic new configuration.

People 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...

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by LH707330
Mon Sep 12, 2022 5:53 pm
Forum: Civil Aviation
Topic: Boom Supersonic new configuration.
Replies: 349
Views: 70590

Re: Boom Supersonic new configuration.

How 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...

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by LH707330
Mon Sep 12, 2022 4:00 pm
Forum: Civil Aviation
Topic: Boom Supersonic new configuration.
Replies: 349
Views: 70590

Re: Boom Supersonic new configuration.

Lookin 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...

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by LH707330
Wed Sep 07, 2022 4:04 am
Forum: Technical/Operations
Topic: Autobrake question: MAX vs. RTO, and performance (and pax)
Replies: 49
Views: 5538

Re: Autobrake question: MAX vs. RTO, and performance (and pax)

Departure 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...

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by LH707330
Sat Sep 03, 2022 11:53 pm
Forum: Technical/Operations
Topic: Fuel Planning Questions
Replies: 15
Views: 2630

Re: Fuel Planning Questions

On 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...

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by LH707330
Sat Sep 03, 2022 11:35 pm
Forum: Technical/Operations
Topic: Wing design and max altitude
Replies: 12
Views: 2573

Re: Wing design and max altitude

Thanks 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...

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by LH707330
Fri Sep 02, 2022 3:45 am
Forum: Technical/Operations
Topic: "Tall Tail" A330-200s
Replies: 14
Views: 6278

Re: "Tall Tail" A330-200s

It 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...

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by LH707330
Thu Sep 01, 2022 2:48 pm
Forum: Technical/Operations
Topic: "Tall Tail" A330-200s
Replies: 14
Views: 6278

Re: "Tall Tail" A330-200s

I 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 ...

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by LH707330
Thu Aug 25, 2022 2:14 pm
Forum: Technical/Operations
Topic: Differently-sized exit doors on narrowbodies vs. widebodies?
Replies: 23
Views: 2857

Re: Differently-sized exit doors on narrowbodies vs. widebodies?

There 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 ...

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by LH707330
Wed Aug 24, 2022 3:39 pm
Forum: Technical/Operations
Topic: A320 Wing Coroguard Paint Questions
Replies: 1
Views: 977

Re: A320 Wing Coroguard Paint Questions

It'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 ...

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by LH707330
Wed Aug 24, 2022 3:35 pm
Forum: Technical/Operations
Topic: Differently-sized exit doors on narrowbodies vs. widebodies?
Replies: 23
Views: 2857

Re: Differently-sized exit doors on narrowbodies vs. widebodies?

There 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...

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by LH707330
Mon Aug 22, 2022 6:37 pm
Forum: Civil Aviation
Topic: Airline seats too small? The FAA may soon change that
Replies: 141
Views: 17637

Re: Airline seats too small? The FAA may soon change that

I 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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