Re: De-rated take-off and climb

Dear XL, Yes the basic idea to run engines at less than their maximum power (TOGA, then MCT) is to reduce the wear, allowing to extend the time between overhaul and saving cost. The actual implementation varies according to aircraft type and engines, but the principle hasn't changed. Even the most m...

Re: Short-haul flights at high altitudes

Dear all, Please let me add a few points to the discussion from a physical point of view: - Aircraft engines generally achieve a better specific fuel consumption (SFC, measured in g/kN*s or lb/lbf*h) at high (climb) thrust than at medium (cruise at intermediate altitude) power setting. While SFC is ...

Re: The A340s purpose

Can the 340 do 2 inboard engines on reverse during descent like the DC-8 could? No, this is not possible. To my knowledge, only the DC-8 and the Concorde could use reversers in flight. Certain Russian models would also use the TR just prior to touchdown as a standard procedure, the 737 can do this ...

Re: First transatlantic flight using 100% green fuel.

There’s an interesting NYT (paywall) on how much corn goes into making the ethanol used for SAF and petrol additives—millions of acres using up deep ground water to grow. We need to think this through. Anyone remember the push for diesel cars and the law of unintended consequences. Mostly the US do...

Re: First transatlantic flight using 100% green fuel.

Dear all, As being professionally involved in the world of renewable energies, please let me add a few thoughts about SAF. 1) While there are certain development projects for battery-powered and "hybrid" aircraft, the bulk of air transport will be assured by aircraft powered by classic fue...

Re: Airbus A321XLR Development / Testing / Production - 2023

One wonders if Airbus couldn't just do a "plug" at the wing root ala the MD80 vis a vis the DC9. Would be relatively cheap, perhaps no need for an all new wing. Get wing area up to ~1,550-1,600 sq feet. The 757 was about 1,900 for comparison, but current engines are much more efficient. A...

Re: Economics & Technicalities of an A380 re-engine program

Dear all, Let's look at the specific fuel consumption of the Trent 900 vs. the Trent 7000: Trent 900: 16 g/kN*s (0,56 lb/lbf*h) in cruise (Source: Wikipedia) Trent 7000: 14.4 g/kN*s (0,51 lb/lbf*h) in cruise (Source: RR) It is therefore realistic to achieve a 10% SFC reduction by upgrading the engin...

Re: GPS spoofing in middle east

Dear all, Thank you for all the interesting information in this thread. One more question from my side: When you refer to "GPS", are you talking about the US-based Navstar/GPS strictly, or to all satellite-based positioning services like Galileo, Glonass, Baidu, etc.? I also wonder wether ...

Re: 707 and DC-8 range capabilities

The DC-8-50 & 62 could do it, as well as the 707-320B & C. The 707-420 couldn't. It is to be noted that the B707-320B first flew in 1962, it was therefore not yet in service in 1961. For the DC-8, the -51 to -54 were indeed certified in 1961, but the -55 (1964) as well as the 60s (1967) cam...

Re: A321 XLR Hot Brakes

The MLW of the A321XLR is 79.2 tonnes (WV100) which is the same MLW as WV051 (with a MTOW of 89 tonnes), the A321 series has been landing at those weights for years. Dear all, I would assume the main brake related issue for the XLR is not regular operations - as stated above, the MLW is no differen...

Re: Airbus A220 Production/Deliveries - 2023

According to airfleets.net, 236 units have been built so far. I am quite sure this number will grow significantly in the near future.
https://www.airfleets.net/listing/csr-6.htm

Hendric

Re: Lufthansa Group News and Discussion - 2023

Dear mtr, While the A380 and the B748 are both the biggest jets you could buy in the 2010s, they are absolutely not interchangeable. The Whale is great for moving lots of people, but not so good for belly cargo. The Jumbo carries less people, but has got a huge space down the belly. The 748 also can...

Re: Pros and cons of backtracking/not backtracking for takeoff (especially in Kathmandu)?

Could it be a factor that the sharp turn at the runway end is causing additional wear on the tires, so airlines would encourage not to backtrack?

Re: Lufthansa Group News and Discussion - 2023

Dear all, Lufthansa plans to extend the re-introduction of the Airbus A380-800 to 8 units, two more vs. the previously communicated 6 aircraft. The two additional frames will be D-AIMA and D-AIMB, currently in deep storage at Teruel, France. The refurbishment of these two oldest A380 in LH colours w...

Re: fuselage diameter of the super caravelle

I am sorry, I misunderstood the initial question - later versions of the "regular" SE210 Caravelle were also named "Super-Caravelle". As I understand now, you were actually talking about the supersonic project by Sud Aviation.

Re: fuselage diameter of the super caravelle

Dear tbp, I found various sources for this information, unfortunately they're not consistent: http://www.geocities.ws/marcmsc/caravtec.htm 297cm https://suren-ratwatte.medium.com/sud-aviation-caravelle-58801622ff34 301cm https://www.flightglobal.com/analysis/analysis-how-suds-caravelle-powered-europ...

Re: Jet Engine Question

Dear all, Fun fact - There is actually a possibility to interchange engines of the type GE CF6-80C2 between the 747-400 and the 767-300ER. This can be useful if you have both aircraft in your fleet and you want to use the freshest, most reliable engines on the 767 before "finishing" them o...

Re: A350 XWB Engine Smoke

Good example here in this SQ clip: https://youtu.be/53QlHbRhZsg?t=1476 Dear Aaron, Interesting observation indeed. Could this phenomenon be related to the fact that the TXWB is renowned for spooling up fast? My hypothesis is that during spool-up, RR intentionally feeds a bit more fuel into the engi...

Re: A350 Engine / T/O Performance

in summary, we have good reasons to assume that the A350-1000 OEW is below 150t, perhaps even significantly so. Just to put these numbers into perspective, a 777-300ER weighs in at around 168t (Wikipedia), a 777-9X at 180t (ok, it's also a bigger airplane) and an Airbus 340-600 at 178t. All of these...

Re: A350 Engine / T/O Performance

The problem is there are elements on here that will take your comments if not corrected as being fact, and may even then use it to change things like Wiki all in some lame attempt to make the A350 look worse than what it is. For example there are elements on here have have actively kept increasing ...

Re: MIT unveils a megawatt motor

It will be a looooooong time before any sector completely eliminates CO2 emissions (or even gets close) unless nuclear power is embraced. The land area needed for, and the variability of, wind and solar power make it impractical to replace nearly 100% of electricity generation, let alone adding the...

Re: MIT unveils a megawatt motor

Batteries must carry their own reactant. Hence the huge weight liability versus hydrocarbons as the reactant for hydrocarbons is oxygen in the atmosphere. If cars had to carry their own reactant like batteries you would need a 1 ton compressed oxygen tank on board. Not very efficient. Precisely. Ev...

Re: MIT unveils a megawatt motor

Thanks for detailed answer! Special thanks for mentioning aramid paper, looks like I need some of that material! I certainly expect things do work; but as you mentioned things quickly become non-trivial. Dear kalvado, If you need to "patch" an insulation at home with high temperature requ...

Re: MIT unveils a megawatt motor

How about acceptable temperature for insulation? Just remember, wiring inside home is rated based on conductor heating up to 80-90C (180-195F) And neodymium magnets are not exactly heat tolerant as well.. Dear Kalvado, Material engineer here, I am an expert for high temperature insulation, having w...

Re: MIT unveils a megawatt motor

Dear all, The development of suitable electric motors is welcome and necessary for a future electrification of aviation. However, as CARST correctly notes, the lack of energy density in current and foreseeable battery technologies will limit the use of this energy source until a disruptive battery t...

Re: Ryanair Chief Pilot Sacked for Alleged Misconduct

Reuters (no additional information besides the name of the Chief Pilot):
https://www.reuters.com/business/aerospace-defense/ryanair-dismisses-chief-pilot-repeated-inappropriate-behaviour-company-memo-2023-06-14/

Ryanair Chief Pilot Sacked for Alleged Misconduct

Dear all, According to the reputable German news source aero.de the chief pilot of Ryanair was dismissed with immediate effect, due to misconduct. According to Ryanair Head of Human Ressources Darrel Hughes (cited in the article linked below), the Chief Pilot is suspected to have sent inappropriate ...

Re: Frankfurt Airport runway closed after new pavement damages wheels

Dear conaly, This issue is bizarre indeed. Apparently, FRA is not the first airport where this coating is being used. No reports of similar issues have yet surfaced. On the positive side, the affected runway is the north-west rwy, the newest and shortest (2700m vs 4000m for the 3 other rwys), it's a...

Re: A350 landing at LaGuardia?

zeke wrote:

Not sure what you are trying to say, the approach speed of the A350 would typically be lower than a 737 or 767, the deceleration rate rate required to make the first exit would be lower.

Re: A350 landing at LaGuardia?

During recent runway works in MEL closing the main 16/34, our A350s were routinly landed on shorter cross strip 27 exiting at N, which is only 4740'. The A350 has lower approach speeds to the A330. Hey Zeke, Did you scrape the first class passengers off the flight deck door after the landing? :-) C...

Re: Low Age A332 without buyer?

Would these birds become candidates for freighter conversion, or is this more a A330-300 thing?

Re: Craziest things you’ve heard on Guard?

I am surprised to hear that a critical emergency infrastructure is abused in this way by people who are supposed to be "professionals".
Isn't there 123.45 for that kind of stuff?

Hendric

Re: Can someone help me calculate the cabin altitude?

Yes, the O2 fraction remains the same, just lower pressure. This is correct, the O2 fraction will remain constant at about 21%. The issue is that at lower cabin pressure (= higher cabin altitude), the partial pressure of O2 will be reduced proportionally, which may become an issue for people with r...

Re: 30 years ago today: the A321 flew for the first time.

Can anyone explane why the 757 has daul tamden landing gear and the A321 doesn't? Hello TWAconnie, There is a significant difference in MTOW between the two aircraft. The A321 ranges from 83t (early -100 models) to 101t (upcoming XLR), whereas the 757 ranges from 115,5t (-200 and -F) to 124t (-300)...

Largest aircraft in current production?

Hello all, I am not sure, but my impression is that the question "Who is currently manufacturing the biggest aircraft?" has an unexpected answer: - In dimensions, the winner is the Airbus A350-1000. - In MTOW, the Boeing 777-F should take the crown. Who would have thought some 10 years ago...

Re: What are the differences between a 1990s and a 2010s airbus a330-300?

Dear all, Among all the improvements listed by Starlionblue, the MTOW increase is the most relevant for the operations of this airliner and greatly contributed to the continued success of the program. Please allow me to expand a little on this aspect. Initially offered in 1992 with a MTOW of 212t, t...

Re: Engine Buzzsaw Fade Out

Dear AviationGeek, There are likely several factors involved. The most important is likely the reduced air density. This will reduce the energy carried by the sound/shock waves coming from the engine. Contributing factor is the speed increase - causing more white noise inside the cabin and re-shapin...

Re: Airbus Freighter (A330F/A350F) Discussion - 2023

Not so long into the future, there will be more 330P2F than the 38 factory built 330-200F freighters...

Re: Confusion over retro liveries

A few years ago, Lufthansa had the whole fleet painted in a retro livery ;.) Looked classy!

Re: A350 NPS Specs

Dear SQ32, I had been made aware of this new production standard a couple of weeks ago and I think that in particular the option to install 10-abreast Economy seats is an important improvement. Remember how the 777 gradually outclassed the A340? Among other things, the main advantage of the 777 was ...

Re: Why are today's flight times longer than 25 years ago?

One point in addition to the ones already mentioned (ground taxi, congestion, cost index, slower mach numbers) is the EU regulation on passenger rights (EC directive No. 261/2004). It gives passengers the right to claim compensation between 250€ and 600€ for flights delayed by more than 3 hours. The...

Re: A350 BTV

BTV seems like a neat tool to assist the pilots in using the runway efficiently, reducing the risk of an airplane crawling along the runway after missing the right exit and forcing the next approaching airplane to go around. Wouldn't it be even more useful in the A320, given the mission profile of t...

Re: Hawker siddeley trident wing

Dear all, Thank you very much for these insights. I definitely learned something. Now I'd like to ask, how do they design the "automatic pitch down in a developing stall" in a straight wing, e.g. for the Q400 or ATR? A higher pitch angle at the wing root wouldn't change the center of lift ...

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?

Re: Hawker siddeley trident wing

Here is the best I have: This is a very interesting drawing. Take a look at the obvious wing twist from the root to the tip. The angle of attack is significantly higher at the root. Would this design feature induce a stall behavior where the root stalls first, moving the center of lift backwards, t...

Re: Time to talk about.....old airlines!

Swissair is an airline to remember. I had the pleasure to fly with their then brand new MD-11 in Business class from ZRH to JFK in 1991. Impeccable service and great food. As a "always hungry" teenager back then, I was served all three menu choices in a row, to the greatest amusement of th...

Re: Luftwaffe A350 Production/Delivery Thread - 2019-2022

Devilfish wrote:

Hopefully, it wouldn't go tech on them anymore.

Re: Luftwaffe A350 Production/Delivery Thread - 2019-2022

Here an article in German about the second A350 for the Government: https://www.aero.de/news-43926/Olaf-Scholz-jettet-bald-mit-Konrad-Adenauer-um-die-Welt.html This aircraft is named after the first chancellor of FRG from 1949 to 1963, Konrad Adenauer. I just wonder why we need three such aircraft?

Re: What did well in 2008?

One sector of aviation not yet mentioned is military aviation. OEMs like Boeing and their suppliers are also active in the military branch, exactly because that sector is much more resilient against recessions. Airbus had several ups and downs following changes in the economic environment, so they d...

Re: 787 vs A330 Runway Performance/Requirements

1. New Ishigaki/Miyako-Narita/Haneda ISG-HND with the A330 would be able to take maximum structural payload, can easily do a 2 hr flight off a 6000' runway Dear zeke, I am always impressed about the RWY performance of modern WB jets at low weight. With a light fuel load, you can essentially operate...