Re: Is it safe?
Aviation teaches you to be cynical, better to assume a system is going to go wrong and train for it, rather than assuming the designers are infallible.
2253 posts • joined 21 May 2008
They could, but that would have been a significant change to the training, i.e. you couldn't just do a quick iPad session and be signed off to fly the Max based on previous 737 experience. I'm not sure how that's changed now but I'd imagine adding an extra switch would require more certification work delaying re-entry to service further.
Damn never realised I wasn't a proper flight sim-user, there I was using it to pre-fly real world sorties but obviously my landing a Piper Cub on the Burj al Arab makes me a gamer. Oh well. Still at least I don't have a stick rammed up my ass.
I've definitely read an account of a convoy escort where the Swordfish's own carrier deliberately overtook it from dead astern and they then landed on. It may have been in 'Achtung Swordfish' which definitely includes an account of assembling one serviceable air-frame from the remains of three wrecks so they could continue flying ASW patrols.
Channel 4 Fact Check here https://www.channel4.com/news/factcheck/factcheck-did-england-exam-system-favour-private-schools
TLDR, the algorithm worked best normalising large class sizes and the teacher assessed grade plays a smaller part in the final result in those cases. So the smaller the class size the greater the weight given to the teacher assessed grades. This doesn't just favour private schools but also Local Authority schools who tend to have small class sizes at sixth form, it does though mean the teacher assessment plays less part in the grades for those at Sixth Form and FE Colleges.
The issue being if you applied the algorithm equally to all class sizes the smaller classes would be even more disadvantaged because you're extrapolating from a much smaller data set. Which would also affect Local Authority schools not just the posh thickos everyone gets so enraged about.
My question is why everyone is so sure they'd get their predicted grades when they've missed several months of school...
In my own small way I'd like to kick China where it hurts my buying as little as possible from Chinese companies or produced in Chinese factories. The former is relatively easy but the latter not so much. Does anyone know of a useful reference for finding out where things are actually produced?
And yes I realise this means I may never be able to buy a phones again.
Agree, my problem with What 3 Words is I can't use it without an app, which is fine right up until I'm in some sort of emergency situation and don't have access to the internet. Or even just walking in the countryside with patchy data.
Still alright for parcel deliveries if using an address is too old hat.
I may be wrong, but I think adding extra sensors etc. would have required re-certification of the whole 737 Max or at least its flight control system, rather than using grand father rights from the original 1960s design. I'm pretty sure if you try and re-certify the whole thing it would fail against the current standards and you'd have to do a massive redesign. At which point a) it would take far too long to compete with the A320 Neo, and b) you may as well make a whole new aircraft.
The reduction in elevator forces meant it was below the limits prescribed in the certification requirements so it's not directly related to a universal type rating. You couldn't legally sell the 737 Max as an airliner without MCAS to correct the issue.
The universal type rating meant they had to minimise the training required to swap between the two models so they basically didn't tell the pilots it existed, which makes it much harder to deal with when it goes wrong.
I think the getting a drone where 'two aircraft are about to safely pass each other' might be the challenging part. Unless you're relying on luck you're going to need a chunky drone to get up to the heights needed for a usable length of time.
You'd also need to find two aircraft heading exactly towards each other only separated by height, in most cases airliners now fly offset to one side of an airway to avoid people going the wrong way down it. The Flight Management Computers even have pre-sets to do this. i.e. you're trying to get two objects in 3D space to collide by controlling their movement in 1 dimension only. Not impossible, but not easy even if their kit actually worked as intended. Not saying you wouldn't get a near miss mind.
Oh and you'd have to spoof a serial number that made the two aircraft manoeuvre the way you wanted, the rule is something like lowest serial always climbs. So depending on the numbers of the two aircraft you want to interfere with the geometry may not work out.
That would work until exactly one person tells someone outside the circle of trust the details. Given the basics of its operation is taught to all commercial pilots I'm not sure how you think anyone could keep a lid on it.
Mind you I'm not sure they've actually proven an ability to usefully spoof it either. At best they're going to have an aircraft say it's further away from another one than it really is, but the windows will still work so they won't have achieved more than just turning the transponder off.
TCAS unit doesn't know who care about where it is or how it's moving. It's just measuring the time taken to receive a reply, and the rate of change of that time to estimate closure rate, and the phase difference of the received signal on two antenna to get a bearing*. The reply it's listening for is literally the serial number of the transponder unit in the other aircraft.
There is nothing in the signals being transmitted or received that gives position information (altitude information is encoded in the reply). This allows non-TCAS equipped aircraft to be detected and avoided by TCAS equipped aircraft as pretty much all aircraft have a transponder fitted so they appear with useful information on ATC radar.
Consequently the only way to do spoofing would appear to be altering the time the response signal is transmitted. I suppose you might be able to transmit two signals slightly out of phase to confuse the bearing calculation as well?
*It's not that accurate in bearing but it's not really an issue.
I suspect the radar is more for things like active cruise control where it keeps you a sensible distance from the car ahead. It may not be possible to pump out enough RF to see as far ahead as needed in this instance without getting embroiled in licensing requirements, which would have to be negotiated for each country where you sold the capability.
More worryingly it goes left instead of right when left is the quicker way of getting to the desired heading. The only reason I can think of for the procedure being designed to go the long way to a desired heading would be to avoid something you'd hit going the other way*.
Although the missed approach plate used to illustrate the article seems to happily take the aircraft over higher ground than the alternative so $deity knows what's happening there.
*And by hit I imagine it'd actually be a case of miss by less than the minimum separation allowed.
To be fair, having access to the same missiles as the enemy is quite handy as you know how its targeting works. The UK was developing its own anti-ship missiles* at the time, but unless you have an infinite budget you have to prioritise what you do.
*Skua and Sea Eagle, the former being used in the conflict in a borderline pre-production state.
If it's the MoD there's a very limited range available in the IT catalogue so you're not getting a Surface Pro. On the plus side even the lowest spec models are powerful enough to run the required applications, which is an improvement.
My understanding is that MoD were planning on rolling out more laptops plus docking stations to replace desktops, but COVID-19 happened first delaying things. So the ~10,000 they've acquired are probably unrelated to the illness itself more the new financial year kicking in.
A drone could, I think it would need to be reasonably large to carry the equipment. If you're happy with a fixed position you could do it with ground based equipment as the height is encoded in the return from the transponder and is easy to change by feeding it information from a modified altimeter. Before anyone gets too excited about doing it on the approach to an airfield the Resolution Advisories are suppressed below 1000' AGL to stop aircraft getting told to break off an approach because someone has turned their transponder on on the ground.
ADS-B transmits the GPS position, but is a fairly recent technology and I don't think it's mandatory everywhere yet. Standard transponders don't transmit the GPS position, the design pre-dating it, ATC receive the transponder information via a secondary surveillance radar*, this gives the bearing and range. The bearing is more accurate than the one a TCAS system generates. The primary and secondary radar information can be displayed together on the same screen, although some control centres only use secondary.
*Primary radar is the classic sort where the reflected energy is used by the receiver to determine range and bearing. Secondary is basically working the same as TCAS by triggering transponders and then listens out for the returns so won't see aircraft without a transponder.
On my phone so slightly condensed but, TCAS asks other aircraft to transmit their transponder signal. This gives the height information and the transponder serial number. There are two receiving antenna which use phase difference to get a bearing to the other aircraft (reasonably accurate...). The time between transmission and reception lets the system calculate range. What it's really interested in is the rate of change of that time which indicates if something is closing and how quickly. If they're at a similar height you start getting alerts. If you get into resolution advisories the serial number is used to decide who should climb.
So everything is relative to the aircraft because that's all that's needed.
The testing was, for obvious reasons, done in a simulator. But they don't say how they'd spoof the transmissions in reality, unless I missed something. With TCAS you're going to have to simulate a transmission coming from a specific location, it all works off the change in time of successive received signals. I'd have thought that's the trickier bit.
ADS-B woukd be a bit easier to spoof as it sends a position rather than just worrying about how quickly things are approaching.
Definitely not designed to be dropped off the side of the ship! It was basically a modified version of the WE177 free fall bomb that could be carried by the ship's helicopter. In the case of the Wasp this involved removing the doors and aircrewman to get enough endurance to carry it far enough away that the ship wouldn't be damaged in the ensuing explosion. It was questionable if the helicopter could clear the drop zone fast enough not to be taken out by the above surface effects of the bomb. Although in the case of the Wasp it may well have been out of fuel by then anyway.
The other customers I can understand being morons. But if the staff are concerned about it don't have them on display to be bought!!
Just to be clear I see no problem with buying non-essential items if you're already going to the shops to buy essentials. On an unrelated note, anyone know what to do with 14 loaves of pretty and a dozen empty wine bottles?
'FTRS or reserves probably shouldn't have access either.'
Pretty hard doing all the mandatory online training without access to the Defence Gateway. Also given the classification of information that it can hold the person who sent the screenshot either didn't break the Official Secrets Act, or the person who put it on the Defence Gateway also did.
That's not to say a disciplinary case isn't warranted but that's got nothing to do with the OSA.
Effectively nowhere if they're lucky. It's £330Bn of guarantees, i.e. if your company takes out a loan to cover it through the pandemic it's backed by the government so if you still go out of business it gets paid off. If you don't go out of business you pay it off not the UK taxpayer.
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