View Full Version : Article in The Economist
mcpilot
19th Jul 2020, 16:23
From an article in The Economist about software engineering:
"Airlines are, for instance, now advised to turn the plane off and on again every 51 days, to stop its computers displaying false data in mid-flight. A similar problem found in 2017 in some aeroplanes made by Airbus, Boeing’s European rival, prompted the European Union Aviation Safety Agency to require that such aircraft be rebooted at least every 149 hours."
The Economist is not known for its inaccuracies. Being a humble PPL I know little about modern avionics but surely starting up from 'cold and dark' would give a reboot to electronics equivalent to "turning the plane off and on"?
When do you assume a long-haul aircraft is ‘cold and dark’? For significant periods of time they are either flying or on turn-round, being maintained, cleaned and re-catered, before heading off again.
wiggy
23rd Jul 2020, 17:09
The Economist is not known for its inaccuracies. Being a humble PPL I know little about modern avionics but surely starting up from 'cold and dark' would give a reboot to electronics equivalent to "turning the plane off and on"?
QA1's given the reason.
Unlike light aircraft, which probably are left "dead" between flights, airliners are often kept powered up, between sectors, either by APU electrics or by Ground Power.
Send a Long Haul aircraft out on a two sector out, two sector back hop from Europe to Australasia (pre-Covid obviously) and it certainly won't be powered down on the transit in the Far East, it may well not be powered down on the turn, so ultimately it could get back into Europe having had portions of the avionics up and running for 60 hours plus...then chuck in a short around when the aircraft gets back to base (aircraft still left electrically powered for engineering, etc) followed by more with ULH sectors and the hours are racking up.
Another example of hours building up is where sector timings are such that a single airframe can "bounce" for several days between base and a single destination with only a couple of hours on the ground between each sector (e.g. 10'ish hour flight, 2 hour turn, rinse and repeat.and repeat...)
It's actually not that common to climb into a "cold and dark", electrically dead long haul flight deck, probably the only place you routinely jump in and found everything turned off is the simulator...:uhoh:
Whinging Tinny
24th Jul 2020, 02:55
It's actually not that common to climb into a "cold and dark", electrically dead long haul flight deck, probably the only place you routinely jump in and found everything turned off is the simulator...https://www.pprune.org/images/smilies/worry.gif
Unless you are an engineer..................
wiggy
24th Jul 2020, 08:53
Unless you are an engineer..................
Fair point.......:ok:
dixi188
24th Jul 2020, 13:09
Didn't Delta Airlines have a policy back in the 80s/90s of not de-powering aircraft unless required to for maintenance, to improve reliability? It's the power off and on that causes things to fail.
727s, MD80s, Tristars, etc.
Some A330 Nav (FMGC) systems used to suffer from way point memory overload. They could only store 200 or so way points, if the memory wasn't cleared regularly the aircraft could lose all its electronic Nav/guidance systems half across the pond.
The temporary cure was to trip the FMGC CBs at every Daily check or power the aircraft down.
Went on for years.
Private jet
5th Aug 2020, 23:38
Didn't Delta Airlines have a policy back in the 80s/90s of not de-powering aircraft unless required to for maintenance, to improve reliability? It's the power off and on that causes things to fail.
727s, MD80s, Tristars, etc.
I think it was Northwest and/or Delta.
Krystal n chips
6th Aug 2020, 06:28
I think it was Northwest and/or Delta.
Didn't Braniff have a similar philosophy with the "Big Orange " ?......possibly with the rest of their fleets as well. Seem to recall various articles about the serviceability record being pretty high as a result.
greatwhitehunter
18th Aug 2020, 17:35
We have had problems on the 777 that did not reset with all power off, (including the ground power turned off at the outlet), but did when the ground power was physically unplugged. Figure that one out. It happened a number of times on different aircraft. Not often but not unknown.
The 320 was similar. Waterline heater failure latched, will not reset until the ext power plug is removed. First time someone told me that I thought it was a wind-up - tried it and it fixed the problem.