My last posting addressed accident flight recorders and airworthiness requirements. That’s not enough. It’s important to note that aircraft equipage standards are addressed in operational rules. So, the airworthiness requirements define what an acceptable installation looks like but as to whether an operator needs to have specific equipage or not, that’s down to the operational rules in each country.
Internationally, the standards and recommended practices of ICAO Annex 6 are applicable. These cover the operation of aircraft. Flight recorders are addressed in para 6.3.1. and Appendix 8. Let’s note that ICAO is not a regulator. There are international standards but operational rules in each country apply to each country’s aircraft.
One of the major advances in accident flight recorders technology is the capability to record more data than was formerly practical. This has led to standards for Cockpit Voice Recorders (CVRs) advancing from 2-hour recording duration to 25-hours.
Proposed rule changes have been hampered by the impact of the global pandemic. Some new operational rules apply only to newly built aircraft. That means some existing aircraft can retain their 2-hour CVRs.
Another technology advance is what’s known as Recorder Independent Power Supply (RIPS). RIPS can provided power to the CVR for at least 10 minutes after aircraft electrical power is lost. The RIPS is often offered as a relatively straightforward aircraft modification.
I do not know if the South Korea Boeing 737-800 was required to have accident recorders with the capabilities listed above. If they were not, then there’s a good basis for recommending that changes be made to existing aircraft.
There’s quite a bit of chatter on social media about accident flight recorders.
One of the skills required by an aircraft accident investigator, and not often mentioned, is the ability to grapple with rules, regulations, and technical requirements. This is given that civil aviation is one of the most highly regulated industries in the world.
The story of the development of the accident flight recorder is a long one. No way can a few words here do justice to all the efforts that has been made over decades to ensure that this vital tool for accident and incident investigation does what it’s intended to do.
In fact, that’s the first technical requirement to mention for accident recorders. Namely, FAR and CS Subpart F, 25.1301: Each item of installed equipment must be of a kind and design appropriate to its intended function. That basic intended function being to preserve a record of aircraft operational data post-accident.
Aircraft accident recorders are unusual. They are mentioned in the airworthiness requirements, however they play no part in the day-to-day airworthiness of an aircraft. The reality is more nuanced than that, but an aircraft can fly safely without working flight recorders.
FAR and CS 25.1457 refers to Cockpit Voice Recorders (CVR)[1] and 25.1459 refers to Flight Data Recorders[2]. Both CVR and FDR receive electrical power from the aircraft electrical bus that provides the maximum reliability for operation of the recorder without jeopardising service to essential or emergency electrical loads. Both CVR and FDR should remain powered for as long as possible without jeopardising aircraft emergency operations.
Before drawing too many conclusions, it’s important to look at the above certification requirements in relation to their amendment state at the time of type certification of an aircraft.
If the aircraft of interest is the Boeing 737-800 then the FAA Type Certification date is 13 March 1998 and the EASA / JAA Type Certification date is 9 April 1998. Without wading through all the detailed condition, the certification basis for the above aircraft type was FAR Part 25 Amendment 25-77 and JAR 25 Change 13 [Note: EASA did not exist at the time].
FAR and CS 25.1457 and 25.1459 were in an earlier state than that which is written above. That said, the objective of powering the recorders in a reliable way was still applicable. There was no requirement for the CVR or FDR to be powered by a battery. What hasn’t changed is the requirement for a means to stop a recorder and prevent erasure, within 10 minutes after a crash impact. That’s assuming that aircraft electrical power was still provided.
So, when it’s reported that the South Korea Boeing 737 accident recorders[3] are missing the final 4 minutes of recoding, the cause is likely to be the loss of the aircraft electrical buses or termination by automatic means or the removal of power via circuit breakers. We will need to wait to hear what is found as the on-going accident investigation progresses.
In my travels, I’ve seen derelict towns. The reason they were built has passed into history. A frantic fever swept through an area like an unstoppable storm. It might have been precious metals that excited the original residents. Gold rushes feed the desire to get rich quick. It doesn’t take the greatest minds in the world to figure out why gold fever will always have an appeal. The onrush of people joining the throng keeps going until opportunities have collapsed.
Breakthrough technologies, or their potential, can be just like a gold rush. There’s no doubt that 2025 will be a year of such phenomena. Top of the list is Artificial Intelligence AI[1]. If you want to be a dedicated follower of fashion[2], then AI is the way to go. Thank you, The Kinks. Your lyrics are as apt now as they were in the 1960s.
Predications range from the best thing since sliced bread to the end of humanity. Somewhere along that line is realism. Trouble is that no one really likes realism. It can be somewhat dull.
I’ve always viewed advancing technologies as a two-edged sword. On the one hand there are incredible benefits to be reaped. On the other, costs can be relatively unpredictable and devastating. I say “relatively unpredictable” as there’s always the advantage of knowledge with hindsight. Lots of commentators love to practice that one.
In desperation to gain the economic benefits of AI the current utterances of the UK Government may seem a little unwise[3]. Certainly, there’s nothing wrong with wishing to build a significant domestic capacity in this area of technology. What’s concerning is to always talk of legislation and regulation as a burden. Particularly when such language comes from lawmakers.
The compulsion to free-up opportunity for a western style gold rush like scenario has a downside. That is all too evident in the historic records. Ministers in this new Labour Government remind me of Mr. Gove’s past mantra – we’ve had enough of experts. Rational dialogue gets sidelined.
Even now we have seen generative search engines produce summaries of complex information sources that are riddled with holes. This experience reminds me of past work cleaning up aviation accident databases. Removing all those 2-engined Boeing 747s and airport IDs with one letter transposed. Data by its nature isn’t always correct. The old saying, to err is human, is always applicable.
The concerning aspect of AI output is its believability. If error rates are very low, then we stop questioning results. It gets taken for granted that an answer to a question will be good and true. There we have a potential problem. What next. AI to check AI? Machines to check machines? There lies a deep rabbit hole.
If you had a freeway billboard, what would it say?
Don’t panic. It’s difficult to better the great Douglas Adam’s words. They seem even more pertinent in 2025 than ever. In essence if you think life is wacky now just wait until you get around the next corner. So, save your energy.
POST: if ever there was a day for these two words then it’s 20th January 2025. Reputedly the most depressing day of the year
Call me a motorhead if you like. It’s the cars and bikes of my youth. I suppose they are associated with good memories. It’s the freedom of the road. In the 1970s-80s that was still a freedom. Summer jams hadn’t crushed the spirt of motoring.
It’s nice to hark back to the analogue era. Long before digital engine controllers made engines practically untouchable. Looking at the basic BMC “A” series engine. Everything was fixable. No degree in engineering required. A 15-year-old could do it.
Now, the Austin A35 van has been elevated to the hall of fame. Without it how would Wallace and Gromit[1] ever foil their nemesis? It’s iconic shape is unmistakable.
The van we owned as a field car had a former life as a chicken shed. Some friends and I bought it from a schoolteacher who’d put it back together. We raced it around the open fields. The rugged little engine held-up long before the bodywork fell apart.
Shame we didn’t see the value in it. 50-years on they are much valued[2]. But I don’t think I’d spend ten grand on one.
British Prime Minister Keir Starmer’s dive to an incredibly low level of popularity is notable. In fact, it’s a bit more than that. It’s record breaking.
A commonly held view seems to be that we elected the Labour Party government in July as the least bad choice. The Tory years had got so utterly terrible that even their devoted supporters bulked at giving them yet another term in office. Combine that with an inexplicable inability to frame a simple story about what Labour stands for and the problem is less surprising.
Keir Starmer is no fool. He’s an intelligent and experienced politician. He’s taken the hard knocks. He’s climbed the slippery pole. But, and there’s a but, something doesn’t jell.
I my humble opinion, the ingredients missing or in excess are categorised like so.
Charisma. It’s so much easier if leader has that indefinable quality. I remember this of Paddy Ashdown. One: you know when they are in the room. No question. People look. Two: they never lack inspiring ideas. Even if they could be off-the-wall. Three: what they say makes an impact.
Eloquence: That ability to coin words and phrases that resonate with lots of everyday people (not just supporters). To speak persuasively, in a way that says we are going on a great journey together. Scripted or not, fluency that appears natural and unforced. Lightness of touch.
Managerialism: Everyone expects confident, capable, competent governance (although we rarely get it). However, we don’t want to see it live on the mainstage, all the time. That phrase about political policy and making sausages is a good one. Lots of people like sausages but few like to know how they are made.
Now, the question I have is: are the “local difficulties” of present fixable?
2025 is going to be a roller coaster of a year. We have washed away any residual millennial mysticism that hit the world in 2000. A whole generation has slipped by. Babies born as London’s Millennium dome was both viewed both with amazement and distain, have jobs that didn’t exist as the fireworks went off.
The so called “smart” phone, and tablets have carved a way into our lives that’s deep and unmovable. Even if the next leap in technology will surely leave them as obsolete.
So, what’s the narrative for 2025 – 2050? Will we sink into the quicksand of nostalgia or herald a new era full of promise? I don’t know. I’ll just keep topping up my glass to ensure it’s half full.
Jeju Air Flight 7C2216, arriving from the Thai capital of Bangkok, at South Korea’s Muan Airport (MWX), crashed at around 9am local time (00:00 GMT/UTC) on Sunday, 29 December 2024.
My condolences to the families and loved ones of those who died or were injured in this fatal aircraft accident.
Pictures of the Jeju Air Boeing 737-800 landing[1] show that no landing gear can be seen deployed. A video image shows the aircraft skidding down the runway at high speed. The aircraft is wings level. It is reported the aircraft overrunning the runway and colliding with a wall or ramp. The video image does suggest that the aircraft engine thrust reversers were deployed. This is wrong. Weight on wheels is needed for deployment.
MWX runway 19 has a Landing Distance Available (LDA) of 2800 m. The local visibility was reported as 9000m and the wind speed at 2kt.
Was the pilot in command trying to go around? The accident flight recordings should answer this question. That is from the aircraft Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR).
This remains a hope. Reports are that the FDR has been damaged. This should not be a surprise given the nature of the impact it suffered. However, both FDR and CVR are designed and tested to survive extreme cases.
The South Korean Ministry of Land, Infrastructure and Transport says that the accident flight and voice recorders have been recovered[2].
Jeju Air is a popular South Korean low-cost airline. The airline was established in 2005.
A full independent accident investigation will no doubt take place. That is in accordance with the standards and recommended practices of ICAO Annex 13.
Current media speculation surrounding possible causes of this Boeing 737 accident do not offer any satisfactory explanation for the sequence of events. For example, it would be astonishing if the root cause of the accident was a bird strike or multiple bird strike shortly before landing. The aircraft has several means to deploy its main undercarriage.
It is likely that safety culture, controller and pilot training, and airport facilities are bigger factors in this fatal accident than the fact that it involved the loss of a Boeing 737-800 aircraft.
NOTE: Boeing 737 “If the gear fails to extend properly or hydraulic system A is lost, the gear can be manually extended by pulling the manual gear extension handles, located in the flight deck.” Landing Gear
POST: The impact test in the applicable technical standards EUROCAE ED55 (FDR) and ED56A (CVR) are demanding. The recorder’s crash protected memory module is fired out of a canon into a shaped target to simulate an accident scenario. It must be readable afterwards.
A lot of wibble is written on the presumption that the older you get the more conservative you get. Whilst this may be true a number of people it’s by no means a rule. Meanwhile media moguls trade on this prehistoric assumption as much as they possibly can.
Even this simple question on politics is open to challenge. Every year the political landscape shifts. What might seem to be conservative a decade ago can now be painted as lefty liberal. So, do you and I change or does the world change around us? Naturally, both.
Again, put the British tabloids and social media aside. They run a shabby soap opera every day. All is not what it seems. Asked “Which political ideologies do Britons have a positive view of?[1]” the results are surprisingly refreshing. Top of the poll comes – environmentalism.
I guess, I am still a believer in the political “bell curve”. The great majority of people are neither tub thumping red necks or wishy-washy socialist spongers. Certainly, that’s what I’ve always found on the doorstep during elections. Valuing family, friends, community, work and having enough to live on without dreading the next bill, that’s a good start.
Yes, my views on a multitude of complex issues have changed but my values remain liberal. Live and let live. Do no harm (if you can avoid it). Encourage everyone to reach their potential. Look at the world with hope and not despair. Avoid gloom mongers.
And I still get a kick out of the story of the boy and the starfish. If you feel you can’t do anything to change the world and it’s all gets too much, think on these few words:
No matter how warm and comfortable, it’s that predicable human factor that’s the difficult one to deal with. Yes, I can say I want natural light, countryside views, just the right temperature and humidity and only pleasant noises. This can all be easily upset.
Distractions are the big one. Love that moment in The Shining when Jack Nicholson sits at his typewriter. Even worse when we all find out what he was typing.
Luckily, my distractions are not that of a towering spooky mountainside hotel. They are social media, my coffee cup, a ring at the door, taking the bins out or some useless attention getting device that should have been switched off ages ago. Even writing these few sentences while I’m supposed to be writing a presentation.
Give me a private space with only a couple of nice distractions. Nothing that goes beep like my German washing machine.
Finding aircraft wreckage in the deep ocean is possible. However, it requires a degree of good fortune. Most of all, it requires the searcher to look in the right places. Lots of other factors come into play, particularly if the ocean floor is uneven or mountainous.
The primary tool for imaging the ocean floor is SONAR. That’s using the propagation of sound in water. SONAR can be of two types. One is called “passive” and the other called “active”.
The first case is like using a microphone to listen to what’s going on around. Of course, the device used is named appropriately: a hydrophone. It’s a device tuned to work in water and not air. Afterall, sound travels much faster in a liquid than it does in air.
Passive SONAR depends on the object of interest making a noise. Just like we have directional microphones so we can have directional hydrophones.
Passive SONAR is only useful if the aircraft wreckage is making a noise. Since in the case of Flight MH370, the battery powered underwater location beacons attached to the accident flight recorders have long since stopped working this kind of SONAR isn’t going to be much use.
Active SONAR is analogous to RADAR. That is where a pulse of high frequency sound is sent out through a body of water. Then sensitive hydrophones pick up a reflection of that pulse. It is detected and all sorts of miraculous digital signal processing is done with the acoustic signal, and an image is then formed. From that displayed image the human eye or sophisticated algorithms can make sense of what they are looking at on the sea floor.
Active SONAR can give both range and bearing (direction). Timing the sound pluses from their transmission to reception can give a way of calculating range. Or distance from the object providing a reflection. Bats know how to do this as they navigate the dark.
In sea water, there are complications. Sound does not always travel in a straight line in sea water. The speed of sound in water depends on salinity, temperature and pressure. All three of these factors can be measured and compensated for in the SONAR signal processing that I mentioned above. Helpfully at ocean depths beyond a kilometre the calculations become easier.
The average depth of the Indian Ocean is over 3 kilometres. It’s mountainous underwater too. So, what are the chances of finding flight MH370 on the ocean floor after 10-years[1]? This prospect goes back to my earlier comment. It requires the searcher to look in the right places.
Just imagine encountering the Grand Canyon for the first time. It’s nighttime. An important object is lost in the canyon. You only have the vaguest theories as to where the object has come to rest. With a handheld touch you go out to search. What are the chances of finding the object?
There are several factors that are in your favour. One, you know what the object might look like or, at least, in part. Two, the easy search locations (flat/smooth) may be covered relatively quickly. Three, certain areas of the rocky canyon have already been searched. Still the odds are against finding the lost object without a high degree of good fortune.
I wish the new planned searchers much good future[2].
NOTE 1: one of my student apprentice projects was to design and build a Sing-Around Velocimeter for use in relatively shallow sea water[3]. It worked but was cumbersome in comparison with the simple throw away devices used for temperature depth profiling.
NOTE 2: To get down to the ocean depths required it’s a side-scan sonar that may be used. This active sonar system consists of a towed transducer array that can be set to work at different depths. Imaging objects on the seafloor and underwater terrain is done as a towed array moves slowly forward through the water. The scanning part is the acoustic beam sweeps left and right. Each scan builds up part of an image.
In operation, as the frequency of the sound in water goes up so does the resolution of a potential image but, at the same time, the range of the sonar system goes down. Thus, a sonar system used for surveying may have low and high frequency settings. Unlike sound in air, here high frequency means above 500kHz.
NOTE 3: What will an aircraft accident recorder look like after a decade in the deep ocean? It might have survived well given the nature of the dark cold pressured environment. This picture is of an accident recorder recovered from relatively shallow sea water (Swiss Air Flight 111).
John Vincent 