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by kalvado
Fri Jun 24, 2022 10:45 pm
Forum: Technical/Operations
Topic: Concorde time spent at max thrust with full reheat
Replies: 23
Views: 1066

Re: Concorde time spent at max thrust with full reheat

I suspect going through M=1.0 would still require an afterburner. I don't think any plane today can accelerate supersonic on turbojet/turbofan with no afterburn. Supersonic cruise without an afterburner is the general goal. Most modern fighter jets can accelerate to supersonic speeds without afterb...

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by kalvado
Fri Jun 24, 2022 7:38 pm
Forum: Technical/Operations
Topic: Concorde time spent at max thrust with full reheat
Replies: 23
Views: 1066

Re: Concorde time spent at max thrust with full reheat

I believe the maximum time in reheat was 15 minutes Is that limited by fuel tank capacity? Probably and perhaps an engine limitation, IIRC that was enough time to allow the acceleration from .95 at mid altitudes to 1.7 Mach around FL 450 after a steady accelerating cruise climb continuing at lower ...

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by kalvado
Fri Jun 24, 2022 7:29 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

You don't have to feel superior, I am referring to the fact that pilot is supposed to take over in case things become nonstandard. Yes, older generation computers are not setup for anything else; they possibly could have more authority, though. Next generation could definitely be more capable. Woul...

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by kalvado
Fri Jun 24, 2022 6:51 pm
Forum: Technical/Operations
Topic: Concorde time spent at max thrust with full reheat
Replies: 23
Views: 1066

Re: Concorde time spent at max thrust with full reheat

Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight. Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again...

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by kalvado
Fri Jun 24, 2022 1:31 pm
Forum: Technical/Operations
Topic: Concorde time spent at max thrust with full reheat
Replies: 23
Views: 1066

Re: Concorde time spent at max thrust with full reheat

Is that limited by fuel tank capacity? Certainly in military circles, afterburner limitations are mostly driven by heat management; nozzles, exhaust ducts, surrounding structure etc. I suspect that Concorde would be no different. Certainly supply of humor to military was recently cut by Congress du...

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by kalvado
Fri Jun 24, 2022 11:33 am
Forum: Technical/Operations
Topic: Concorde time spent at max thrust with full reheat
Replies: 23
Views: 1066

Re: Concorde time spent at max thrust with full reheat

Max Q wrote:
I believe the maximum time in reheat was 15 minutes

Is that limited by fuel tank capacity?

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by kalvado
Thu Jun 23, 2022 3:52 pm
Forum: Technical/Operations
Topic: Concorde time spent at max thrust with full reheat
Replies: 23
Views: 1066

Re: Concorde time spent at max thrust with full reheat

Reheat is used on every take-off, its light-up sequence taking place on the roll as the engines accelerates up to full power – it needs the mass flow associated with an N1 of 81% or more to function. It is switched off at 500ft on a standard flight or at noise abatement cut-back where needed. For t...

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by kalvado
Mon Jun 20, 2022 8:41 pm
Forum: Technical/Operations
Topic: GIV Twin Engine Plight Planning Chart
Replies: 14
Views: 606

Re: GIV Twin Engine Plight Planning Chart

Sort of a useless chart, have to go elsewhere to find trip fuel, find alternate and holding fuel. Once you know those inputs, the chart gives you initial FL. Big Whoop! But, it’s 30+ years old. There is clearly a bit more to this chart. Purple line coming from another chart at right-bottom should r...

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by kalvado
Mon Jun 20, 2022 3:41 pm
Forum: Technical/Operations
Topic: GIV Twin Engine Plight Planning Chart
Replies: 14
Views: 606

Re: GIV Twin Engine Plight Planning Chart

OK, so in this screen shot, landing weight of 50 + 11000 fuel burn == 61000 TOW. Blue line is laid over 61000 and this tells me I can just make it to FL430 but not FL450? https://imgur.com/SmpIw5Z Correct. Well, at least initially you are limited to 430. As @GalaxyFlyer said, you should be able to ...

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by kalvado
Mon Jun 20, 2022 1:54 pm
Forum: Technical/Operations
Topic: GIV Twin Engine Plight Planning Chart
Replies: 14
Views: 606

Re: GIV Twin Engine Plight Planning Chart

So this is what I ended up with. Line #7 (blue line) representing the flight level line. https://imgur.com/Bk0ieFq THat is perfectly correct. I would put it a bit differently, though - this line represents TOW, and hence maximum FL you can climb right after takeoff. Same thing, just a bit different...

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by kalvado
Mon Jun 20, 2022 6:14 am
Forum: Technical/Operations
Topic: GIV Twin Engine Plight Planning Chart
Replies: 14
Views: 606

Re: GIV Twin Engine Plight Planning Chart

rfresh737 wrote:
I don’t get how you determine 68klb TO weight? I have to be missing something.

They plot for 49 klb landing weight, and get 19 klb fuel burn for whatever flight distance they solve for.
49+19=68

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by kalvado
Mon Jun 20, 2022 12:39 am
Forum: Technical/Operations
Topic: GIV Twin Engine Plight Planning Chart
Replies: 14
Views: 606

Re: GIV Twin Engine Plight Planning Chart

Are you talking about "max initial FL" lines? Think about them as constant take-off weight lines. upper left border says "max initial FL410 @ MTOW (74.5klb). Sample plotted situation of 49klb landing + 19 klb fuel burn = 68klb TOW allows climb to FL410 (line to the left of planning po...

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by kalvado
Fri Jun 17, 2022 1:51 pm
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

You could only interfere with gauges if you able to access the cable running between the engines for example and the piece of avionics that drives the gauges. To do that you need to be not in the aircraft cabin. These data busses are not new tech, they are very old reliable tech that only allows so...

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by kalvado
Fri Jun 17, 2022 10:51 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

There was nothing between them, not even a thinnest condom. You cannot get data without some connection. You are reading my posts on this forum without a direct connection to the device I am posting from, you cannot tell what I am reading, what I am doing, or control my device by reading a post. Th...

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by kalvado
Fri Jun 17, 2022 6:14 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Hasty generalisation fallacy. The data is generated in the first place because it has to be output to the displays in the cockpit, the transponder, ADS-B, the DFDR, and so on. Using the data for IFE does not require redesigning the computing units that actually generate the data. It just requires r...

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by kalvado
Fri Jun 17, 2022 5:32 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data...

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by kalvado
Fri Jun 17, 2022 5:29 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Burden of proof fallacy... And of course finding all the relevant information requires IFE system manual and full 737 wiring diagram. But it is usual "through obscurity" thing I have a better and more interesting question for you, though. Why flight data is available to IFE at all? Appare...

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by kalvado
Thu Jun 16, 2022 11:42 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Ad hominem fallacy. You're not refuting the actual point. Regardless of how mask deployment works on the NG, the guy in question was lying. There is no way to do what he claimed. That's what many IT guys said. Next thing they learn is it would take $1M to a Bitcoin account to get things back to nor...

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by kalvado
Thu Jun 16, 2022 7:32 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

No, because he was caught lying red handed. He tweeted in flight he was on an aircraft and was going to set off the passenger oxygen EICAS. After the United 737 landed, he was arrested, they seized and listed all the tech gear he had including devices, cables, thumb drives. There was no cat 6 cable...

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by kalvado
Thu Jun 16, 2022 1:22 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

So you arguments boil down to this guy uses incorrect terminology hence cannot be right. No, because he was caught lying red handed. He tweeted in flight he was on an aircraft and was going to set off the passenger oxygen EICAS. After the United 737 landed, he was arrested, they seized and listed a...

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by kalvado
Thu Jun 16, 2022 12:14 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

If my memory serves me right, flight control story was about 757 or 767. At least the story I have in mind was about a newer generation one. Not new enough to be designed with paranoiac data security thoughts, but new enough to have significant computing on board. "no direct link" may be ...

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by kalvado
Wed Jun 15, 2022 3:31 pm
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

That is a good tough question. Of course, I have no rock solid answer for you - such things are generally not becoming public until there is gross problem, like it happened with MCAS. However, my strong impression is that certification system, like any system designed to impose a set of fixed requi...

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by kalvado
Wed Jun 15, 2022 12:16 pm
Forum: Technical/Operations
Topic: Which is the most FUEL EFFICENT REGIONAL aircraft in the world ?
Replies: 16
Views: 1875

Re: Which is the most FUEL EFFICENT REGIONAL aircraft in the world ?

Dear FR, The ATR-72 had been advertized as "the most fuel efficient commercial aircraft" by the manufacturer literally decades ago, sporting an equivalent fuel consumption of "2,5 l/100km per passenger". This is still a good value by today's standards and it was achieved through...

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by kalvado
Wed Jun 15, 2022 11:48 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Do you have any specific examples of "compliance through obscurity"? MCAS I knew you'd say that. ;) And that's fair. However, I see MCAS as an outlier. Any other examples? Honestly curious. That is a good tough question. Of course, I have no rock solid answer for you - such things are gen...

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by kalvado
Wed Jun 15, 2022 1:41 am
Forum: Technical/Operations
Topic: Tail Anti-Ice leading edge question.
Replies: 20
Views: 1612

Re: Tail Anti-Ice leading edge question.

Going back to the metal strip on the fin leading edge, I am fairly sure all A350s come with it. Some operators may just choose to paint it for aesthetics. I can't think of any operators with the strip painted. Which ones are you thinking of? Since it is for erosion protection it is likely that they...

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by kalvado
Tue Jun 14, 2022 7:05 pm
Forum: Technical/Operations
Topic: Tail Anti-Ice leading edge question.
Replies: 20
Views: 1612

Re: Tail Anti-Ice leading edge question.

So of Airbus like I said some 320/330/380 etc operators have either not had that metal strip installed or they have painted it and this includes the newer generation of NEO’s, but yet to see an A350 without it, so wasn’t sure if it was just something airlines have not done yet or chosen not to do, ...

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by kalvado
Tue Jun 14, 2022 1:42 pm
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

This is easy to achieve by the way. My previous job was telematics for tanker trucks and I used this kind of connectors to make sure I cannot send anything to the internal truck CAN bus: https://copperhilltech.com/cancrocodile-contactless-can-bus-reader/ Not this particular one, though. They are es...

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by kalvado
Tue Jun 14, 2022 11:24 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Last time I was talking to an IFE vendor engineer, and he was saying that the interface unit with the aircraft is physically incapable of outputting any signal to the aircraft side so this should not be a problem. This is easy to achieve by the way. My previous job was telematics for tanker trucks ...

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by kalvado
Mon Jun 13, 2022 2:00 pm
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

Most of that is the same information displayed on the cabin displays for the cabin crew. Our cabin crew have to initialise the mast et IFE control with the flight number and destination. I was recalling my memory on that very same screen when writing. And on some setup if the flight crew entered th...

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by kalvado
Sun Jun 12, 2022 11:40 am
Forum: Technical/Operations
Topic: How does the IFE display things like altitude and speed
Replies: 49
Views: 3566

Re: How does the IFE display things like altitude and speed

There was a case of a computer engineer who did manage, apparently, to access more than he should have been able to: https://www.wired.com/2015/05/feds-say-banned-researcher-commandeered-plane/ What he claimed he could do on a real aircraft just is not possible. The IFE is an independent network, i...

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by kalvado
Thu Jun 09, 2022 1:13 am
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

What is "still happening despite training programs" is that many regulators and operators don't seem to train in a very rigorous fashion, and adopt punitive approaches to non-normal events Right now, that choosen balance is to give the pilot authority over everything - but at the same tim...

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by kalvado
Wed Jun 08, 2022 11:39 am
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

Can we stop with the skygod references, it seems like an underhanded insult against people who have acquired different skills. Point I am trying to test is that " human as the ultimate solution " approach is the biggest philosophical problem in flight control flow. It doesn't matter how y...

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by kalvado
Wed Jun 08, 2022 10:47 am
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

What is "still happening despite training programs" is that many regulators and operators don't seem to train in a very rigorous fashion, and adopt punitive approaches to non-normal events Right now, that choosen balance is to give the pilot authority over everything - but at the same tim...

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by kalvado
Wed Jun 08, 2022 3:22 am
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

There is no assumption that humans are superior. The autopilot can fly the plane more accurately than we can. However, the autopilot can only do so with valid inputs. If the inputs are not valid, keeping the autopilot is very dangerous. As my first flight instructor said, "Remember, the autopi...

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by kalvado
Mon Jun 06, 2022 1:49 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

You don't need to be Chuck Yeager to deal with unreliable airspeed, especially if, as in this case, you know it is unreliable. You do need training. The pilots would also not have speed data. But they did have a methodology to deal with the issue that the flight control and autoflight systems lacke...

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by kalvado
Sun Jun 05, 2022 4:19 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

Then we have a disagreement—pilots should be perfectly capable of flying the plane without the autopilot system keeping them out of trouble. An old school position, possibly. I totally hear you. However, everything and everyone fails once in a while (says a guy who accidentally tore 5/8" harde...

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by kalvado
Sun Jun 05, 2022 2:51 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

The “computers” had the all the authority they needed to do their task—straight and level, in trim. When they lost a vital piece of information, they said “we can’t do our task any longer, you try it human”. Human only had do nothing, leave the thrust at cruise setting, maintain attitude, wait unti...

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by kalvado
Sun Jun 05, 2022 2:18 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

Give computers more authority and the risks grow rapidly. AF447 was in trim and at a usable thrust setting for the conditions. If the pilots did nothing, they’d have landed at CDG. The “computers” were fine until the pilots added inputs which were not designed for—large pitch up beyond the performa...

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by kalvado
Sat Jun 04, 2022 9:06 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

I suspect "human is superior" assumption is the biggest design flaw here I myself don't feel "superior", and I think it would be the case for most of pilots as well. But we, as humans, have an ability to assess large amounts of data and predict an outcome - a thing I refer to as...

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by kalvado
Sat Jun 04, 2022 1:18 pm
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

You don't need to be Chuck Yeager to deal with unreliable airspeed, especially if, as in this case, you know it is unreliable. You do need training. The pilots would also not have speed data. But they did have a methodology to deal with the issue that the flight control and autoflight systems lacke...

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by kalvado
Sat Jun 04, 2022 12:53 am
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

I guess your answer emphasizes two approaches to automation. Not only in plane FBW, but as a wider question, perhaps for automotive industry and also other. Do we want the computers to offload work and allow humans to concentrate on non-standard situations, or should the computer assist be there al...

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by kalvado
Fri Jun 03, 2022 10:53 am
Forum: Technical/Operations
Topic: Air France 447: 13 years on
Replies: 55
Views: 4431

Re: Air France 447: 13 years on

That's what I tried to say: the envelope protection system that would have saved the aircraft was not working (or not fully). It was just my 2 cents on the debate about whether there should be more or less automation. I guess your answer emphasizes two approaches to automation. Not only in plane FB...

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by kalvado
Mon May 30, 2022 7:40 pm
Forum: Technical/Operations
Topic: Dirty airplanes
Replies: 11
Views: 3388

Re: Dirty airplanes

Currently, WN has the advantage of not running scheduled redeyes, allowing them to perform maintenance overnight and potentially wash aircraft more frequently I wonder what is the percentage of US3 aircraft doing red-eyes. I would think a relatively small fraction. Well, I'd say most of mainline ai...

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by kalvado
Mon May 30, 2022 11:24 am
Forum: Technical/Operations
Topic: Dirty airplanes
Replies: 11
Views: 3388

Re: Dirty airplanes

I’ve noticed the same thing. I was at ABQ today and was shocked how dirty the Mesa E175s I saw were. Absolutely filthy. I would assume WN birds are equally filthy but the blue fuse hides dirt better. Currently, WN has the advantage of not running scheduled redeyes, allowing them to perform maintena...

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by kalvado
Sun May 29, 2022 11:59 am
Forum: Technical/Operations
Topic: 737 spoiler mixer / ratio changer question.
Replies: 6
Views: 1471

Re: 737 spoiler mixer / ratio changer question.

As for maintenance manual, this weak signal may be a good diagnostic metric for some reason. For example, weak can become zero if there is any problem with flow or alignment...

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by kalvado
Sat May 28, 2022 3:29 pm
Forum: Technical/Operations
Topic: Static wicks and electric GA aircraft...
Replies: 5
Views: 1249

Re: Static wicks and electric GA aircraft...

It will not work.

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by kalvado
Sat May 28, 2022 2:33 pm
Forum: Technical/Operations
Topic: Is an Aircraft Perfectly Balanced 50/50?
Replies: 17
Views: 1895

Re: Is an Aircraft Perfectly Balanced 50/50?

You will get a fuel imbalance alert if your tank balance left/right exceeds a threshold. Can you give an idea of what that threshold is? I suspect around 1% of max fuel or so? From here https://www.boeing.com/commercial/aeromagazine/aero_09/fuel_textonly.html This table for example https://www.boei...

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by kalvado
Fri May 27, 2022 8:08 pm
Forum: Technical/Operations
Topic: Is an Aircraft Perfectly Balanced 50/50?
Replies: 17
Views: 1895

Re: Is an Aircraft Perfectly Balanced 50/50?

For an aircraft athwartship CG is not as critical as it is for helicopters We care where CG is longitudinally but don’t consider where it is left/right of the buttline. You will get a fuel imbalance alert if your tank balance left/right exceeds a threshold. Can you give an idea of what that thresho...

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by kalvado
Fri May 27, 2022 7:34 pm
Forum: Technical/Operations
Topic: Is an Aircraft Perfectly Balanced 50/50?
Replies: 17
Views: 1895

Re: Is an Aircraft Perfectly Balanced 50/50?

Given latest discussion about manufacturing tolerance affecting empty weight, as well as design asymmetry - such as different doors for R1 and L1, I doubt there is a perfect symmetry.
Arm is small, as it was pointed out, so effect is limited

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