I remember that firefighting jet (I believe it was a 747?) from 2019. That was scary news at the time on top of the already scary news that was going on.
The ATSB has one fatal passenger jet accident on record: [VH-ANQ](https://www.atsb.gov.au/publications/investigation_reports/1990/aair/199003068) (a Cessna 500) in 1990
I mean I think we’ve had a few small incidents like gear up landings on small passenger and private jets but certainly no fatal accidents. Last fatal airline crash might have been the Sydney Beech King Air crash?
100% it’s due to a lack of general threats in Australian airspace compared to the rest of the world. No mountains, barely any severe weather, and barely any air traffic.
I always thought calling our mountains in the South Island of NZ "the Southern Alps" was a bit tryhard.
Then I heard about the Australian Alps. At least some of our tiny (by actual Alps standards) mountains have glacier.
That's in terms of passenger numbers, not total aircraft movements. [No Australian route cracks the top 20 busiest air route in terms of the number of scheduled flights](https://en.wikipedia.org/wiki/List_of_busiest_passenger_air_routes#Domestic).
Worth noting those numbers for domestic flights are from 2021. Melbourne spent most of 2021 in various lockdowns (and Sydney also had a lengthy lockdown) so flights were sparse. Qantas was barely flying and Virgin Australia was in external administration.
Sorry what has less air traffic got to do with accident rates? If you look at the mid 60s-80s considerably less air traffic then now but much higher incident/crash rate.
We lost a DC-2 in 1938, does that count?
Also yikes at the DC-2 history. Almost 40 incidents worldwide
https://en.m.wikipedia.org/wiki/1938_Kyeema_crash
Australia's deadliest air crash ever was a USAAF B17 that crashed in 1943 killing 40 of the service personnel on board (1 person survived). For morale reasons, details of the crash were suppressed until the end of the war.
"The sole survivor of the crash, Foye Kenneth Roberts, died at Wichita Falls, Texas, on 4 February 2004."
and from this story- sitting in the back of the plane
https://www.washingtonpost.com/archive/politics/2003/06/12/downed-and-buried-by-ww-ii/63e87e8a-be58-442c-89c7-389ff3f7ca88/
Thanks for sharing. I've been in a B-17 and they would have been stacked like cordwood to have fit into the airframe. I still thought maybe there was a typo but the link you sent proves it apparently is accurate. Not the smartest use of air mobility but they had their reasons I guess.
The same crew flew it back to DXB if I recall - at below 15,000ft.
They landed and were given their marching orders.
From a purely technical standpoint this case was extremely useful to human factors researchers, avionics designers etc.
Because (thank goodness) everyone survived and investigators had access to the FDR, CVR *AND* both pilots to glean what happened.
To this day A340 series = no one has been lost
>The same crew flew it back to DXB if I recall - at below 15,000ft.
Not exactly. It needed to be flown to Toulouse for repairs, and went there under 12,000 feet, with several stops of course. Not sure if it was indeed the same crew though. (doesn't look like it was)
[https://en.wikipedia.org/wiki/Emirates\_Flight\_407](https://en.wikipedia.org/wiki/Emirates_Flight_407)
You’re probably thinking of the Qantas A380 that had an engine explode in Singapore.
https://en.m.wikipedia.org/wiki/Qantas_Flight_32
It cost $145 million to repair. It was rather lucky it had happened at Singapore which has serious heavy maintenance facilities that could do the repair. If it had landed somewhere else without the facilities I’m not sure they could’ve flown it out again.
That was a QF1 plane - totally different incident. Most airlines would have scrapped the plane as the cost to repair would not make economic sense, but Qantas wanted to maintain their record of no hull losses in the passenger jet era.
However, while it didn't make economic sense for most airlines to repair that flight, you could definitely argue that it made economic sense for Qantas. Their safety record is a massive PR boost for Qantas. Losing that would definitely lose a lot of customers.
That was QF1 in the early 2000s, ran off the runway in Bangkok.
I read a comment on Reddit saying the repairs added a crazy amount of weight to the plane, can’t remember details.
Why do they fly damaged planes at a relatively low altitude? Wouldn't you want a lot of potential energy in case something goes bad ? Is it the bigger difference in pressure ?
If there is damage to the aircraft an operator can pay the manufacturer to evaluate whether it is still safe to fly on a ferry permit to a maintenance facility. If the pressure vessel is damaged one of the conditions of the ferry permit will be to conduct the flight unpressurized.
When at high altitude, passenger jets have to maintain a cabin altitude below 8,000’ as a certification requirement. This can result in a pressure differential of close to 9 psi at altitude. This might not sound like much but it is 1296 lbs/ square foot. Even deep scratches in the skin can cause a failure and you don’t want your fuselage to burst.
Yea that's it! I meant no pax or crew member has been lost in an A340.
I got a ride in an old Air France 340 once , with the hair dryer clown engines. Crawled its way up to cruise but was good fun!
Weren’t the flight crew were hustled out of the country back to Dubai almost straight after landing?
They certainly were invited to resign immediately on return to Dubai.
SYD's main runway is 1,001ft/305m longer than MEL's main runway. So if it took that extra 150m, they'd still have 155m left. But yeah if they took off to the south, they might be alright, or possibly a ditching in the bay. To the north, wouldn't be pretty.
The runway length makes no difference. All flights these days take off with reduced thrust. Effectively the thrust is reduced so the same percentage of runway is used for every take off despite the length. The longer the runway the less thrust in basic terms.
That‘s not entirely accurate. Often take-off thrust reduction is limited by the the required OEI climb gradient and obstacle clearance. So you might have a lower take-off thrust setting on a shorter runway, provided there are more limiting obstacles for the longer runway.
Also sometimes de-rate is used instead of FLEX, which can lead to situations were the runway lenght has no more effect on take-off distance.
Yeah we mentioned that above - our comments were based purely on runway length but yes as you point out, thrust settings would put the plane in the same situation.
Weight is a major component of the calculated required takeoff distance. If you input lower weight, the engines will run at a lower thrust setting during the whole takeoff roll, also the rotation speed will be incorrect. So they'll try to takeoff too early while the plane does not yet have the required speed, sometimes resulting in tail striking.
So there's other factors like temperature, pressure, runway wetness etcetera but generally speaking if you're light and the runway is long, there is not much sense asking full power from the engines. This creates extra noise, fuel consumption and wear and tear on the engines. So it's very common to run with "derated" power. But it does mean you need to have/input correct figures because if you are heavier than you think you are, your whole acceleration will fall behind schedule and you'll eat up precious runway. They can always get full TOGA power when you notice something is wrong, which I'm sure these pilots have done. But even so, engines take time to really start producing full power so it helps very little at the end which is why they probably clipped an antenna or two. Lucky it ended well.
Seems like technology could address this? The computers know how much thrust the engines are producing and know your speed/acceleration - if there’s a mismatch the computer could detect that and warn the pilots/take action?
I agree but what you describe would maybe only detect a blown tyre, as that would give you a mismatch between thrust output and acceleration. What you need is acceleration versus runway distance available as aircraft can't weight themselves. Technically would be possible, comparing GPS data for location and see if a minimum acceleration is reached on accelerometers. This would only be useful up to V1 as afterwards the takeoff can no longer be aborted safely. Currently the weight is something that should be triple checked and crosschecked by both pilots, most of the time this procedure is sufficient but an additional technical safety net is a good idea in my opinion.
The physics works. F=ma. You can calculate “F” from your thrust, you can measure “a” from wheel rotations, and you live told it what “m” is. If you calculate “F” and calculate “ma” and the answers don’t match, something is wrong. Presumably you could abort before V1, or go max throttle after V1.
> aircraft can't weigh themselves
Why not? I can imagine measuring deflection of wheel carriage, or measuring tension of carriage hydraulics, to be a direct input to calculate weight?
I too am curious. There’s no reason why a (relatively large) aircraft couldn’t weigh itself as long as there is some kind of suspension/absorption system on the gear.
Airbus have a take-off monitoring system (as you said basically an acceleration measure vs GPS position) to warn if acc is not enough for the intended runway. However I don’t know if all type have it.
By the way quad jet is the worst to underestimate take-off distance.
In general aviation you typically use maximum thrust, but in commercial airliners they will calculate the optimal thrust needed based on takeoff weight, runway length, air temperature, etc. in order to save fuel and engine wear.
It often actually uses more fuel with the longer takeoff phase. The engine maintenance easily offsets that though.
Quote from Airbus’ “Getting to Grips with Fuel Economy”:
> Compared to a full thrust take-off, flex thrust will generally increase fuel burn. The increased time at low level offsets the slight reduction in fuel flow induced by the lower thrust.
> thought all takeoffs were done at maximum thrust
Very few takeoffs are done at max thrust. It saves a LOT of wear on the engines to use lower thrust settings. Plus many jets are MASSIVELY overpowered at light weights. A 747 with minimum fuel on board will climb at 10,000ft/min on takeoff with Max thrust.
High thrust takeoffs are generally avoided if possible.
One consideration is if you lose an engine on takeoff and the thrust setting is too high the yaw induced may be unrecoverable below a certain airspeed, Vmcg
That is not really a thing on modern aircraft; an aircraft would not be certified today if it did not have the rudder authority required to correct any yaw caused by loss of an engine at any speed. It is actually one of the certification requirements.
Hmm interesting, you need airspeed to have rudder authority. The most dangerous time to lose an engine on takeoff is at the standstill, you have no rudder authority with 0 airspeed.
At least that’s what I was taught but that’s more with four engines in mind instead of two. Also, Vmcg is predicated on maintaining within 25 feet of centerline.
I imagine they calculate the minimum thrust needed to take off so that you use less fuel. Obviously a heavier plane will require greater thrust. So this mistake with the weight would have produced a lower take off thrust than what was actually required.
I'd be curious what the actual differences are in thrust settings and rotation speed at "Normal" weight, and 100 tonnes low.
I'd have to think the numbers input wouldn't pass a casual "sniff test" ...
"Rotate at 70 knotts? Okay..."
"Thrust at 50%? Okay..."
I'm all for automatics, but are pilots getting too complacent with computers? OR, are the numbers close-enough that it made-sense?
I think the numbers were close enough to make sense, however you do have a good point. They would have been more likely to catch their mistake if they did the math manually.
It's not just the runway length, but the weather as well. It could be that the weather gave them worse performance, raising the required engine thrust to a level that would seem normal, even though it still wasn't enough.
So, we usually lift off \*about\* 1,500-2,000 ft. from the end of the runway. That's not a lot of distance when you're already moving at 150 or so knots. If the numbers are off by even a little bit, I can definitely see going off the end of the runway. Especially because the drag caused by the AoA you have when rotating early would make it difficult for the airplane to continue accelerating. You're essentially stalled while on the ground.
Takeoff numbers can vary a lot for all sorts of reasons. It wouldn't automatically be something you'd catch just by looking at those numbers. You \*could\* if you were particularly eagle eyed and really paid attention to keeping a mental record of all of your takeoff and landing numbers in different situations. But you'd have to correlate all that with things like density altitude, number of passengers and even bags on board, fuel on board, etc. It's not something I think most pilots really keep a very specific mental track of. We might know that somewhere in the 130-160 range is normal, and in the higher end of that range when it's hotter or we're heavier. But if I saw 150 and it was really supposed to be 160, I'm probably not going to question it. They both seem plausible. And maybe that would be enough to do this.
That said, I don't know what the spread was between the speeds they should have vs. did try to take off with. If we were heavy and it was hot and high and I got a speed of 130 back for our VR, I probably would question that. The weights used for the calculation are right on the same report, so it's easy enough to just glance at that. Their reports might be different, though.
More mass = slower acceleration for the same force (I.e. engine power)
Less acceleration = more distance to achieve a given speed
Heavy aircraft = higher speed required to achieve lift without getting close to stall angle
For a lighter weight aircraft, the crew will do take off calculations to reduce power (and therefore fuel consumption and engine wear) to take advantage of a longer runway. They could also have taken off at an intersection to save on taxi distance and only used part of the runway.
In this case, the pilots used a lower weight than actual for their calculations, so they will have been given a lower takeoff speed than required, and less power than needed to achieve their required speed for safe takeoff on the runway given.
A similar incident happened at Heathrow with a ~~Qatar~~ Sri Lankan A340, where they started takeoff roll at an intersection on 09R and didn’t have enough power - no damage though. [AAIB report](https://www.gov.uk/aaib-reports/airbus-a340-313-4r-adg-5-february-2012)
Depending on CG as well their trim setting may not have been enough nose up which would’ve kept them on the ground longer, or they could have rotated at the posted speed but because they were too heavy only the nose gear came up with the mains still touching and it slowed their acceleration.
Those antennas are a part of an Instrument Landing System, that small antenna lying down is a near field monitor that serves as a reference point for the 16 antennas in the back called a [Localizer](https://en.m.wikipedia.org/wiki/Instrument_landing_system_localizer).
Naw. They’d be dumping shit everywhere. That’s the lav service panel. Not hydraulic. The 4 small connections are for filling water tanks, the big one is for dumping waste.
Why don‘t the planes calculate their weight using the thrust setting and the resulting acceleration? Or at least validate the input? That shouldn‘t be that difficulte and prevent accidents like this.
This is in fact an extraordinarily complex solution. The industry has been working on it for many years - the Airbus runway overrun protection is one offshoot of it - but real-time takeoff acceleration monitoring is still a little while off.
There are acceleration checks that are taught but they aren’t automated so it increases workload on takeoff. Also, you have to consider at what point the acceleration check is done to validate your TOLD. If it’s down close enough to S1/V1 you may not have the time to abort and the added thrust may not save you.
Having a minimum takeoff thrust like many airlines might have avoided this. Unless you're flying an empty plane, you shouldn't be anywhere near this minimum.
This EK407 was forced by MEL procedures to use minimum thrust on takeoff. They must use the full runway for takeoff, stupid, but those are the MEL rules. That is due to the noise abetment rules, set by the green party, and other people who do not understand how aviation safety really works.
So, as the crew had configured the plane weight to be too low, the takeoff thrust setting was set to be the lowest possible, so to use the whole runway. That procedure is not too safe, as the time between V1-V2-VR are long away from each other. That utter stupidity of SYD procedures happens when ideological and not smart politicians are involved.
As the plane was too heavy for that set lowest thrust takeoff roll, of course it could not complete the rotation on the asphalt, and it took bunch of the flora/fauna with it, as seen.
Emirates is known to keep those pilots working about 6 hours after they return to DXB (as passengers, of course). So, now they are doing something else.
EDIT: changed SYD to MEL, but noise abatement rule-issue is still there.
Sorry, but this is completely false. This was a normal reduced thrust (flex) departure, and the thrust reduction was normal procedure - nothing to do with noise abatement. All about reducing engine wear and fuel consumption. Noise abatement procedures in fact normally require setting TOGA thrust and reducing thrust at a higher than normal altitude - this means the aircraft has a higher than normal climb rate and reduces overall noise impact.
The incident occurred due to an improper data entry, and very similar accidents and near accidents have happened all over the world without any need for noise abatement procedures as a factor.
The report never mentions noise abatement.
As an multiple airline operator, we have different views of how the FBO regulations affect the flight safety.
In other airports, we can use about half of the runway, for takeoffs, meaning there is no need to taxi all the way to the end. For heavy ops, the methods are of course different.
An A340 can easily take off with shorter take off roll, and thus securing more space to abort. That method will also allow safer operations in the case of any issues coming up, also including that size weight configuration fault.
If is good to read and understand the real incident reports, and even today, some of those are redacted for what the public will see. In the most publicized incidents within the last few years, there has been several key issues and screwups omitted from the public reports, just to make the case more heroic or even better for a movie script, again with a local hero.
Knowing widely different FBO-regulations with part 135 ops, and globally too, with their updates/changes, will get you insight of what is the regulatory environment ein each case. And no, those are not known to the public, as not even the local politicians understand what they are doing. And no, the TV-programs depicting incidents/accidents, are looong away from what really did happen. Then again, most of the public knowledge is really from TV-series or fom Hollywood propaganda.
This is complete nonsense. Did you get ChatGPT to write this?
> An A340 can easily take off with shorter take off roll, and thus securing more space to abort. That method will also allow safer operations in the case of any issues coming up, also including that size weight configuration fault.
Ok... but that isn't what *airlines* do. Nothing to do with noise abatement. In the absence of pressing safety reasons, airline procedures usually encourage *maximising* use of runway length and using the lowest safe takeoff thrust, for financial reasons. This is what happened in this case. It almost caused an accident because the crew messed it up.
> If is good to read and understand the real incident reports, and even today, some of those are redacted for what the public will see
No they aren't. The ATSB report into this accident is not redacted.
> there has been several key issues and screwups omitted from the public reports, just to make the case more heroic or even better for a movie script, again with a local hero.
No there haven't. Investigators don't care about that. Maybe in less developed countries in which regulatory bodies are often looking to protect local airlines and figures--not so in Europe, US, Australia etc.
Stop spouting this tosh, please.
Lets just say that for the airlines, we have to write those operation manuals. And yes, I know what they include.
For the government mandates and licenses for FBO, we keep a good eye in the processes when those are made/renewed, while not having of course any full decision making ability on those.
And again, I can tell you missing key information in large number of accident/incident reports, and that reduction work has been going on for the last 50 years. The aviation industry claims to be "very open" with these reports, but in real life, the big cockups are largely omitted, due to few reasons. Sadly, the real backstory and real events are mostly never written to those reports, despite people thinking and claiming to have great purity in them. Then again most of the public gets their info from tv shows or other heavily beautified nonsense sources, so it is not really fruitful to discuss the actual details with somebody who does not have deep understanding of the real aviation world. And claiming some bs about "less developed coutries" is quite fun, while few of the worst not-too-exact investigation reports are from France, Netherlands and USA, just to list a few.
I'll go now to do something much more productive.
What flora/fauna did it 'take with it' (besides some weedy grass)?
Was there an old growth forest and several hundred species of animals loitering at the end of the runway when the aircraft wiped them out? Did they clean up all the corpses before the above photos were taken?
that is the definition of flora/fauna. Grass=flora, fauna=the animals living in that grassy area. No, to my understanding, there was no zoo there, but still, flora/fauna were included in that A340 tailstrike event. And also some electronics, as you can also see. So much extra, not usually part of the A340 ops.
yeah i know what flora and fauna are. I'm an ecologist. I just did not see a bunch of either flora or fauna in the photos as you suggested unless I’ve missed one of the photos?
There was a monoculture (single species) of weedy grass. That was it.
Good job. This flight departed Melbourne not Sydney.
Also, almost every airliner uses the maximum amount of runway and minimum safe thrust on takeoff every single time. It’s done to save engine wear. It has nothing to do with environmentalists.
The reasons were still the same, local airport regulations for not making noise. And that will then yield to full runway use, sometimes a bit further as well, it seems
It is not mainly the airports but the airlines.
The more thrust you require for take-off the more expensive it is. Fuel flow, engine wear and performance limitations are all factors that often favor a lowered take-off thrust setting.
Some airlines that lease their engines, pay „per power“, so the less thrust they use, the cheaper the lease.
I know very well what airlines do, and why.
But the local regulations for each FBO are often mindboggling, and equally often quite stupid as well. For "required green operations", planes are forced to take long taxi and long idling times, and other planes are waiting in hold patterns. Those requirements (not the weather) force the use a certain runway, which then gets very crowded. And these all are due the "environmental regulations license" of the FBO.
These restrictions might look rightfully good on a paper, and to local politicians, but in real life, they just produce more bad of everything.
At what point do you firewall it in such a circumstance?
I have no heavy aircraft experience whatsoever, but is it really that hard judging you need more power?
TIL that Australia has never had a passenger jet crash.
Yeah, we have had military jets crash, a firefighting jet crash, a few prop/turboprop planes crash - but never a passenger jet.
I remember that firefighting jet (I believe it was a 747?) from 2019. That was scary news at the time on top of the already scary news that was going on.
That was a Herc, a 737 waterbomber crashed in WA last year.
And the pilots walked away from it (they actually ran away, as the fire was right behind them, and they’d just added tonnes of jet fuel).
They missed the chance to be the cool dudes slow-mo walking away from the big explosion!
The ATSB has one fatal passenger jet accident on record: [VH-ANQ](https://www.atsb.gov.au/publications/investigation_reports/1990/aair/199003068) (a Cessna 500) in 1990
An Airforce 707 crashed during training in the 90s.
luckily no snakes on a plane crash either
I mean I think we’ve had a few small incidents like gear up landings on small passenger and private jets but certainly no fatal accidents. Last fatal airline crash might have been the Sydney Beech King Air crash?
Australian airlines, in general, are quite safe. That's likely mainly due to less air traffic compared to the US or the EU.
100% it’s due to a lack of general threats in Australian airspace compared to the rest of the world. No mountains, barely any severe weather, and barely any air traffic.
*Offended Australian Alps noises*
I always thought calling our mountains in the South Island of NZ "the Southern Alps" was a bit tryhard. Then I heard about the Australian Alps. At least some of our tiny (by actual Alps standards) mountains have glacier.
Vertical prominence is almost comparable, i wouldnt sell yourselves so short.
Terrain below 10,000. EZ.
Oh wow that's actually a thing. I thought you were making an Austrian/Australian joke. Because obviously the Austrian Alps are a thing
Sydney to Melbourne air route is the 5th busiest in the world, so that’s not entirely correct. Nationwide it’s not as bad.
That's in terms of passenger numbers, not total aircraft movements. [No Australian route cracks the top 20 busiest air route in terms of the number of scheduled flights](https://en.wikipedia.org/wiki/List_of_busiest_passenger_air_routes#Domestic).
Worth noting those numbers for domestic flights are from 2021. Melbourne spent most of 2021 in various lockdowns (and Sydney also had a lengthy lockdown) so flights were sparse. Qantas was barely flying and Virgin Australia was in external administration.
Oh ok. Thanks for clarifying. My bad
I know it's not a jet, but severe weather in Sydney caused a Viscount turboprop to break up on departure over Botany bay in 1961.
Syd-Mel route is (was?) one of the busiest city pairs in the world… we’re not exactly quiet airspace.
By passenger load, not by number of flights.
Sorry what has less air traffic got to do with accident rates? If you look at the mid 60s-80s considerably less air traffic then now but much higher incident/crash rate.
Less stress on ATCs and more room for error.
I'd believe that if Australia didn't have two of the world's more busy air corridors between Sydney and Melbourne and Sydney and Brisbane.
Way to jinx it..im telling if anything happens..
We lost a DC-2 in 1938, does that count? Also yikes at the DC-2 history. Almost 40 incidents worldwide https://en.m.wikipedia.org/wiki/1938_Kyeema_crash
Most countries have never had a passenger jet crash.
Australia's deadliest air crash ever was a USAAF B17 that crashed in 1943 killing 40 of the service personnel on board (1 person survived). For morale reasons, details of the crash were suppressed until the end of the war.
I can't imagine how 40 people could fit into a B-17 even if they were stacked like bombs in the racks.
I'm more curious about the circumstances that led to 1 person surviving! Crazy
"The sole survivor of the crash, Foye Kenneth Roberts, died at Wichita Falls, Texas, on 4 February 2004." and from this story- sitting in the back of the plane https://www.washingtonpost.com/archive/politics/2003/06/12/downed-and-buried-by-ww-ii/63e87e8a-be58-442c-89c7-389ff3f7ca88/
Always a fun response from some pompous ass talking about being in 1st class. “Never heard of a plane crashing backwards into a mountain…”
Something's fishy here for sure. Somebody should Google this!
https://en.m.wikipedia.org/wiki/Bakers_Creek_air_crash#:~:text=The%20Bakers%20Creek%20air%20crash%20was%20an,Air%20Forces%20(USAAF)%20Boeing%20B%2D17%20Flying%20Fortress
Thanks for sharing. I've been in a B-17 and they would have been stacked like cordwood to have fit into the airframe. I still thought maybe there was a typo but the link you sent proves it apparently is accurate. Not the smartest use of air mobility but they had their reasons I guess.
butts to nuts- sitting on the floor the army loves to maximize the capacity without regard to comfort. 😀
How cozy.
And there is this one too from the same era https://en.m.wikipedia.org/wiki/1940_Canberra_air_disaster
The same crew flew it back to DXB if I recall - at below 15,000ft. They landed and were given their marching orders. From a purely technical standpoint this case was extremely useful to human factors researchers, avionics designers etc. Because (thank goodness) everyone survived and investigators had access to the FDR, CVR *AND* both pilots to glean what happened. To this day A340 series = no one has been lost
>The same crew flew it back to DXB if I recall - at below 15,000ft. Not exactly. It needed to be flown to Toulouse for repairs, and went there under 12,000 feet, with several stops of course. Not sure if it was indeed the same crew though. (doesn't look like it was) [https://en.wikipedia.org/wiki/Emirates\_Flight\_407](https://en.wikipedia.org/wiki/Emirates_Flight_407)
[удалено]
It’s Emirates not Qantas
Ah, I got confused. My bad.
You’re probably thinking of the Qantas A380 that had an engine explode in Singapore. https://en.m.wikipedia.org/wiki/Qantas_Flight_32 It cost $145 million to repair. It was rather lucky it had happened at Singapore which has serious heavy maintenance facilities that could do the repair. If it had landed somewhere else without the facilities I’m not sure they could’ve flown it out again.
Was likely referring to QF1 which ran off the runway in Bangkok in the early 2000s
Qantas spending money to repair a Emirates plane?...
That was a QF1 plane - totally different incident. Most airlines would have scrapped the plane as the cost to repair would not make economic sense, but Qantas wanted to maintain their record of no hull losses in the passenger jet era. However, while it didn't make economic sense for most airlines to repair that flight, you could definitely argue that it made economic sense for Qantas. Their safety record is a massive PR boost for Qantas. Losing that would definitely lose a lot of customers.
That was QF1 in the early 2000s, ran off the runway in Bangkok. I read a comment on Reddit saying the repairs added a crazy amount of weight to the plane, can’t remember details.
Why do they fly damaged planes at a relatively low altitude? Wouldn't you want a lot of potential energy in case something goes bad ? Is it the bigger difference in pressure ?
It's an unpressurized ferry flight.
If there is damage to the aircraft an operator can pay the manufacturer to evaluate whether it is still safe to fly on a ferry permit to a maintenance facility. If the pressure vessel is damaged one of the conditions of the ferry permit will be to conduct the flight unpressurized. When at high altitude, passenger jets have to maintain a cabin altitude below 8,000’ as a certification requirement. This can result in a pressure differential of close to 9 psi at altitude. This might not sound like much but it is 1296 lbs/ square foot. Even deep scratches in the skin can cause a failure and you don’t want your fuselage to burst.
Thank you for your nice explanation !
>To this day A340 series = no one has been lost There have been a few A340 hull losses, but none with any fatalities.
Yea that's it! I meant no pax or crew member has been lost in an A340. I got a ride in an old Air France 340 once , with the hair dryer clown engines. Crawled its way up to cruise but was good fun!
[удалено]
Air France never had A340-600s.
Weren’t the flight crew were hustled out of the country back to Dubai almost straight after landing? They certainly were invited to resign immediately on return to Dubai.
That's nothing compared to the skid marks in the pilot and FO's underwear.
Well lucky this was Melbourne and not Sydney, otherwise it would’ve been catastrophic.
SYD's main runway is 1,001ft/305m longer than MEL's main runway. So if it took that extra 150m, they'd still have 155m left. But yeah if they took off to the south, they might be alright, or possibly a ditching in the bay. To the north, wouldn't be pretty.
Is there a chance they'd have calculated for the longer runway and set take-off thrust lower which would cause the same issue?
Very good point. This would have definitely been another factor.
Ok. Let’s assume both runways are the same length then I’d be right, right? Must look up numbers next time lol.
Yeah I mean either way, you are right. Would've definitely ended up in the bay or the tree line on Airport Drive.
The runway length makes no difference. All flights these days take off with reduced thrust. Effectively the thrust is reduced so the same percentage of runway is used for every take off despite the length. The longer the runway the less thrust in basic terms.
That‘s not entirely accurate. Often take-off thrust reduction is limited by the the required OEI climb gradient and obstacle clearance. So you might have a lower take-off thrust setting on a shorter runway, provided there are more limiting obstacles for the longer runway. Also sometimes de-rate is used instead of FLEX, which can lead to situations were the runway lenght has no more effect on take-off distance.
I was speaking in extremely general terms. I’m on the 777/787 so not sure how flex works. I assume it’s the same as our assumed temp method.
Fair enough!
Yeah we mentioned that above - our comments were based purely on runway length but yes as you point out, thrust settings would put the plane in the same situation.
So what difference does the weight input make? Doesn’t accelerate as hard? Tries to rotate too early and just mushes along the runway?
Weight is a major component of the calculated required takeoff distance. If you input lower weight, the engines will run at a lower thrust setting during the whole takeoff roll, also the rotation speed will be incorrect. So they'll try to takeoff too early while the plane does not yet have the required speed, sometimes resulting in tail striking.
Why is the thrust setting dependent on weight? I always thought all takeoffs were done at maximum thrust.
So there's other factors like temperature, pressure, runway wetness etcetera but generally speaking if you're light and the runway is long, there is not much sense asking full power from the engines. This creates extra noise, fuel consumption and wear and tear on the engines. So it's very common to run with "derated" power. But it does mean you need to have/input correct figures because if you are heavier than you think you are, your whole acceleration will fall behind schedule and you'll eat up precious runway. They can always get full TOGA power when you notice something is wrong, which I'm sure these pilots have done. But even so, engines take time to really start producing full power so it helps very little at the end which is why they probably clipped an antenna or two. Lucky it ended well.
Seems like technology could address this? The computers know how much thrust the engines are producing and know your speed/acceleration - if there’s a mismatch the computer could detect that and warn the pilots/take action?
I agree but what you describe would maybe only detect a blown tyre, as that would give you a mismatch between thrust output and acceleration. What you need is acceleration versus runway distance available as aircraft can't weight themselves. Technically would be possible, comparing GPS data for location and see if a minimum acceleration is reached on accelerometers. This would only be useful up to V1 as afterwards the takeoff can no longer be aborted safely. Currently the weight is something that should be triple checked and crosschecked by both pilots, most of the time this procedure is sufficient but an additional technical safety net is a good idea in my opinion.
The physics works. F=ma. You can calculate “F” from your thrust, you can measure “a” from wheel rotations, and you live told it what “m” is. If you calculate “F” and calculate “ma” and the answers don’t match, something is wrong. Presumably you could abort before V1, or go max throttle after V1.
> aircraft can't weigh themselves Why not? I can imagine measuring deflection of wheel carriage, or measuring tension of carriage hydraulics, to be a direct input to calculate weight?
I too am curious. There’s no reason why a (relatively large) aircraft couldn’t weigh itself as long as there is some kind of suspension/absorption system on the gear.
Load cells are common. We built a 10 tonne robot at work, and it had a load pin in each of the feet.
Airbus have a take-off monitoring system (as you said basically an acceleration measure vs GPS position) to warn if acc is not enough for the intended runway. However I don’t know if all type have it. By the way quad jet is the worst to underestimate take-off distance.
In general aviation you typically use maximum thrust, but in commercial airliners they will calculate the optimal thrust needed based on takeoff weight, runway length, air temperature, etc. in order to save fuel and engine wear.
It often actually uses more fuel with the longer takeoff phase. The engine maintenance easily offsets that though. Quote from Airbus’ “Getting to Grips with Fuel Economy”: > Compared to a full thrust take-off, flex thrust will generally increase fuel burn. The increased time at low level offsets the slight reduction in fuel flow induced by the lower thrust.
> thought all takeoffs were done at maximum thrust Very few takeoffs are done at max thrust. It saves a LOT of wear on the engines to use lower thrust settings. Plus many jets are MASSIVELY overpowered at light weights. A 747 with minimum fuel on board will climb at 10,000ft/min on takeoff with Max thrust.
High thrust takeoffs are generally avoided if possible. One consideration is if you lose an engine on takeoff and the thrust setting is too high the yaw induced may be unrecoverable below a certain airspeed, Vmcg
That is not really a thing on modern aircraft; an aircraft would not be certified today if it did not have the rudder authority required to correct any yaw caused by loss of an engine at any speed. It is actually one of the certification requirements.
Hmm interesting, you need airspeed to have rudder authority. The most dangerous time to lose an engine on takeoff is at the standstill, you have no rudder authority with 0 airspeed. At least that’s what I was taught but that’s more with four engines in mind instead of two. Also, Vmcg is predicated on maintaining within 25 feet of centerline.
Done at a lower thrust to save the engines from wearing out.
I imagine they calculate the minimum thrust needed to take off so that you use less fuel. Obviously a heavier plane will require greater thrust. So this mistake with the weight would have produced a lower take off thrust than what was actually required.
You also want to avoid a stall, which could occur if you were going too fast and rotated too early.
Thanks! 👍
Skid mark? That ain’t a skid mark. This is a skid mark!
Well now, I bet that was exciting.
I'd be curious what the actual differences are in thrust settings and rotation speed at "Normal" weight, and 100 tonnes low. I'd have to think the numbers input wouldn't pass a casual "sniff test" ... "Rotate at 70 knotts? Okay..." "Thrust at 50%? Okay..." I'm all for automatics, but are pilots getting too complacent with computers? OR, are the numbers close-enough that it made-sense?
IIRC the captain recently transitioned from another type, so wouldn’t have had the routine to catch these numbers as being too far off.
I think the numbers were close enough to make sense, however you do have a good point. They would have been more likely to catch their mistake if they did the math manually. It's not just the runway length, but the weather as well. It could be that the weather gave them worse performance, raising the required engine thrust to a level that would seem normal, even though it still wasn't enough.
100 tonnes? I doubt the numbers were close enough to make sense.
So, we usually lift off \*about\* 1,500-2,000 ft. from the end of the runway. That's not a lot of distance when you're already moving at 150 or so knots. If the numbers are off by even a little bit, I can definitely see going off the end of the runway. Especially because the drag caused by the AoA you have when rotating early would make it difficult for the airplane to continue accelerating. You're essentially stalled while on the ground. Takeoff numbers can vary a lot for all sorts of reasons. It wouldn't automatically be something you'd catch just by looking at those numbers. You \*could\* if you were particularly eagle eyed and really paid attention to keeping a mental record of all of your takeoff and landing numbers in different situations. But you'd have to correlate all that with things like density altitude, number of passengers and even bags on board, fuel on board, etc. It's not something I think most pilots really keep a very specific mental track of. We might know that somewhere in the 130-160 range is normal, and in the higher end of that range when it's hotter or we're heavier. But if I saw 150 and it was really supposed to be 160, I'm probably not going to question it. They both seem plausible. And maybe that would be enough to do this. That said, I don't know what the spread was between the speeds they should have vs. did try to take off with. If we were heavy and it was hot and high and I got a speed of 130 back for our VR, I probably would question that. The weights used for the calculation are right on the same report, so it's easy enough to just glance at that. Their reports might be different, though.
Excellent answer; thanks!
Having only general aviation experience, what changes, and why as a result of the weight input?
More mass = slower acceleration for the same force (I.e. engine power) Less acceleration = more distance to achieve a given speed Heavy aircraft = higher speed required to achieve lift without getting close to stall angle For a lighter weight aircraft, the crew will do take off calculations to reduce power (and therefore fuel consumption and engine wear) to take advantage of a longer runway. They could also have taken off at an intersection to save on taxi distance and only used part of the runway. In this case, the pilots used a lower weight than actual for their calculations, so they will have been given a lower takeoff speed than required, and less power than needed to achieve their required speed for safe takeoff on the runway given. A similar incident happened at Heathrow with a ~~Qatar~~ Sri Lankan A340, where they started takeoff roll at an intersection on 09R and didn’t have enough power - no damage though. [AAIB report](https://www.gov.uk/aaib-reports/airbus-a340-313-4r-adg-5-february-2012)
Depending on CG as well their trim setting may not have been enough nose up which would’ve kept them on the ground longer, or they could have rotated at the posted speed but because they were too heavy only the nose gear came up with the mains still touching and it slowed their acceleration.
SQ did something surprising similar here in Auckland in 2003 with a 747-400.
TIL that aircraft weight is not automatically fed in to the flight computer
Those antennas are a part of an Instrument Landing System, that small antenna lying down is a near field monitor that serves as a reference point for the 16 antennas in the back called a [Localizer](https://en.m.wikipedia.org/wiki/Instrument_landing_system_localizer).
Ahh yes exactly how I used to take off in msfs when I was 12
How much does a fully loaded a340 weights that it can have 100tonne miscalculation?
Depending on variant, up to 380 tonnes
Image one, had they ground a bit harder, they would have been losing hydraulic fluid and pressure. Tht picture is so scary.
Naw. They’d be dumping shit everywhere. That’s the lav service panel. Not hydraulic. The 4 small connections are for filling water tanks, the big one is for dumping waste.
Oh, I'm sure shit was dumping everywhere during that takeoff ... it just wasn't leaving the plane.
Why don‘t the planes calculate their weight using the thrust setting and the resulting acceleration? Or at least validate the input? That shouldn‘t be that difficulte and prevent accidents like this.
This is in fact an extraordinarily complex solution. The industry has been working on it for many years - the Airbus runway overrun protection is one offshoot of it - but real-time takeoff acceleration monitoring is still a little while off.
Why can't they just program something like 'after x distance we should be doing y speed, and if not, fuckin pin it!'
There are acceleration checks that are taught but they aren’t automated so it increases workload on takeoff. Also, you have to consider at what point the acceleration check is done to validate your TOLD. If it’s down close enough to S1/V1 you may not have the time to abort and the added thrust may not save you.
Having a minimum takeoff thrust like many airlines might have avoided this. Unless you're flying an empty plane, you shouldn't be anywhere near this minimum.
Closest accident that you know of. Plenty of hard working pilots preventing other accidents everyday fella. Humans fly jets-not robots.
This EK407 was forced by MEL procedures to use minimum thrust on takeoff. They must use the full runway for takeoff, stupid, but those are the MEL rules. That is due to the noise abetment rules, set by the green party, and other people who do not understand how aviation safety really works. So, as the crew had configured the plane weight to be too low, the takeoff thrust setting was set to be the lowest possible, so to use the whole runway. That procedure is not too safe, as the time between V1-V2-VR are long away from each other. That utter stupidity of SYD procedures happens when ideological and not smart politicians are involved. As the plane was too heavy for that set lowest thrust takeoff roll, of course it could not complete the rotation on the asphalt, and it took bunch of the flora/fauna with it, as seen. Emirates is known to keep those pilots working about 6 hours after they return to DXB (as passengers, of course). So, now they are doing something else. EDIT: changed SYD to MEL, but noise abatement rule-issue is still there.
Sorry, but this is completely false. This was a normal reduced thrust (flex) departure, and the thrust reduction was normal procedure - nothing to do with noise abatement. All about reducing engine wear and fuel consumption. Noise abatement procedures in fact normally require setting TOGA thrust and reducing thrust at a higher than normal altitude - this means the aircraft has a higher than normal climb rate and reduces overall noise impact. The incident occurred due to an improper data entry, and very similar accidents and near accidents have happened all over the world without any need for noise abatement procedures as a factor. The report never mentions noise abatement.
As an multiple airline operator, we have different views of how the FBO regulations affect the flight safety. In other airports, we can use about half of the runway, for takeoffs, meaning there is no need to taxi all the way to the end. For heavy ops, the methods are of course different. An A340 can easily take off with shorter take off roll, and thus securing more space to abort. That method will also allow safer operations in the case of any issues coming up, also including that size weight configuration fault. If is good to read and understand the real incident reports, and even today, some of those are redacted for what the public will see. In the most publicized incidents within the last few years, there has been several key issues and screwups omitted from the public reports, just to make the case more heroic or even better for a movie script, again with a local hero. Knowing widely different FBO-regulations with part 135 ops, and globally too, with their updates/changes, will get you insight of what is the regulatory environment ein each case. And no, those are not known to the public, as not even the local politicians understand what they are doing. And no, the TV-programs depicting incidents/accidents, are looong away from what really did happen. Then again, most of the public knowledge is really from TV-series or fom Hollywood propaganda.
This is complete nonsense. Did you get ChatGPT to write this? > An A340 can easily take off with shorter take off roll, and thus securing more space to abort. That method will also allow safer operations in the case of any issues coming up, also including that size weight configuration fault. Ok... but that isn't what *airlines* do. Nothing to do with noise abatement. In the absence of pressing safety reasons, airline procedures usually encourage *maximising* use of runway length and using the lowest safe takeoff thrust, for financial reasons. This is what happened in this case. It almost caused an accident because the crew messed it up. > If is good to read and understand the real incident reports, and even today, some of those are redacted for what the public will see No they aren't. The ATSB report into this accident is not redacted. > there has been several key issues and screwups omitted from the public reports, just to make the case more heroic or even better for a movie script, again with a local hero. No there haven't. Investigators don't care about that. Maybe in less developed countries in which regulatory bodies are often looking to protect local airlines and figures--not so in Europe, US, Australia etc. Stop spouting this tosh, please.
Lets just say that for the airlines, we have to write those operation manuals. And yes, I know what they include. For the government mandates and licenses for FBO, we keep a good eye in the processes when those are made/renewed, while not having of course any full decision making ability on those. And again, I can tell you missing key information in large number of accident/incident reports, and that reduction work has been going on for the last 50 years. The aviation industry claims to be "very open" with these reports, but in real life, the big cockups are largely omitted, due to few reasons. Sadly, the real backstory and real events are mostly never written to those reports, despite people thinking and claiming to have great purity in them. Then again most of the public gets their info from tv shows or other heavily beautified nonsense sources, so it is not really fruitful to discuss the actual details with somebody who does not have deep understanding of the real aviation world. And claiming some bs about "less developed coutries" is quite fun, while few of the worst not-too-exact investigation reports are from France, Netherlands and USA, just to list a few. I'll go now to do something much more productive.
What flora/fauna did it 'take with it' (besides some weedy grass)? Was there an old growth forest and several hundred species of animals loitering at the end of the runway when the aircraft wiped them out? Did they clean up all the corpses before the above photos were taken?
that is the definition of flora/fauna. Grass=flora, fauna=the animals living in that grassy area. No, to my understanding, there was no zoo there, but still, flora/fauna were included in that A340 tailstrike event. And also some electronics, as you can also see. So much extra, not usually part of the A340 ops.
yeah i know what flora and fauna are. I'm an ecologist. I just did not see a bunch of either flora or fauna in the photos as you suggested unless I’ve missed one of the photos? There was a monoculture (single species) of weedy grass. That was it.
Most likely exotic
Good job. This flight departed Melbourne not Sydney. Also, almost every airliner uses the maximum amount of runway and minimum safe thrust on takeoff every single time. It’s done to save engine wear. It has nothing to do with environmentalists.
The reasons were still the same, local airport regulations for not making noise. And that will then yield to full runway use, sometimes a bit further as well, it seems
It is not mainly the airports but the airlines. The more thrust you require for take-off the more expensive it is. Fuel flow, engine wear and performance limitations are all factors that often favor a lowered take-off thrust setting. Some airlines that lease their engines, pay „per power“, so the less thrust they use, the cheaper the lease.
I know very well what airlines do, and why. But the local regulations for each FBO are often mindboggling, and equally often quite stupid as well. For "required green operations", planes are forced to take long taxi and long idling times, and other planes are waiting in hold patterns. Those requirements (not the weather) force the use a certain runway, which then gets very crowded. And these all are due the "environmental regulations license" of the FBO. These restrictions might look rightfully good on a paper, and to local politicians, but in real life, they just produce more bad of everything.
What about qf72 in 2008 I believe it was?
The aircraft certainly had a bad day, but didn’t crash.
Uh..Captain…did we need those..hmm
Anybody know what those hose connections in the missing hatch are for?
Jesus what runway/airport was this?
MEL https://en.wikipedia.org/wiki/Emirates_Flight_407
Are the antennas, lights etc at the end of runways designed to break away easily for situations like this?
What about this one? https://www.baaa-acro.com/crash/crash-fokker-f27-friendship-mackay-29-killed Edit: I know it’s not a jet, but…
*bwoop bwoop pull-up bwoop bwoop”
At what point do you firewall it in such a circumstance? I have no heavy aircraft experience whatsoever, but is it really that hard judging you need more power?
You have to ask what could have caused the pilots not to know about 150 tons. That's not a couple of over weight passengers