|
Could it be helpful to focus on what might have happened to the aircraft somewhere NE of KL, instead if endless debate on SAR issues,or diversions on pax breathing advice? That expertise is not necessarily located in R&N, although there are some here who can contribute.
IMHO, the former might possibly lead to the latter. In other words, start at the beginning, instead of charging off in all directions and making this thread almost incomprehensible? I believe we should be covering all bases, but please avoid a high-sprited chase down random alleys. If PPRuNe can be helpful, it's proclaimed professional focus would be a strength. Random chat isn't doing that. |
In our hitech world of today, where military sats in their geo stationary orbits around the planet and sophisticated radar heads covering every avaiable square foot of terrain can spot even a mozzie on the loose, with the seas patrolled with nuke subs and sewn with sonoboys that can hear a flatus of a mariner at a distance of 50 miles, how can it be possible for your every day , run of the mill variety type airliner to go into stealth mode for so long. That is what puzzles me most.
|
Tim Hamilton, it would be handy to know, when that aircraft last had a D check. And at 14 years, she would have had a couple, and what were the results of her last D check.
|
VinRouge wrote;
What if they were already on the flight deck? Plus, to depressurise the aircraft, you would either have to turn off the aircon packs or engine bleed valves (slow decompression), or deselect the automated system and manually drive the outflow valve open (depressurise as fast as you like). Whilst I fly 767s and not 777s, so the details are likely a little different, but the basic system architecture would be pretty much the same. Playing with the aircon/pressurisation system on the overhead panel is not going to go unnoticed by the highjacker who would be watching the pilots like a hawk. Any triple 7 chaps reading please do confirm or correct. |
Isca
back on page 112 DYE wrote in post 2234 (now 2230) Quote: Checked FR24 at 07 MAR 2014 - 18:10 UTC (08 MAR 2014 02:10 local time) FR24 shows SQ68 FL300 SIN - BCN B777W approx 200 miles north-west of Penang. I have tried to reproduce this using flt SQ68 and MH370 and can't anyone else tried Going to very embarassing if this is true There are, however anomalies with the data as presented - for an example, set the time to 17.00 on March 7 and watch what KAL672 (and the neighbouring CCA970) do whilst MAS370 is heading for the Malaysian coast. Perhaps anomalies are to be expected, given that this is unofficial data, but to see 2 reciprocal tracks in the surrounding area of the event under question, AND within a few minutes of the disappearance seems somewhat . . . . odd! :confused: Bear in mind you will not see MAS370 heading NW of Penang as (allegedly) it's transponder is off and therefore there is no ADS-B data to superimpose on this image. |
The hand over on this route is usually KL to Singapore on VHF followed by a short period on Singapore HF/CPDLC followed by a hand off to Saigon on VHF. The communications and ATC are, in my experience (25 years) usually excellent.
Singapore Radio on HF 8942 is one of the better in the region. Of course, we don't usually keep a listening watch on HF as mostly we use HF Selcal. However, any distress call on VHF 121.5 would have been heard by any aircraft in the area. Even at that time of night there are dozens of aircraft on that airway. If an emergency transmission was made it must have been heard by someone! An absolutely catastrophic flight deck event IMHO. |
FYI the UK glider altitude record is just under 39000ft.
Whether this was done with a constant flow O2 system or a diluter-demand system I've no idea - but is was not using any form of pressure breathing O2 equipment or suit. My own system says that it is rated up to 40000ft |
ADS-C and CPDLC used in this region ???
|
Originally Posted by michael0658
(Post 8368934)
The radio horizon at 35,000 ft is about 230 nm for a ground ATC. At its last reported position, this plane was beyond the Line of Sight (LOS) radio horizon for all ATC systems and ground radio.
|
Ok Mixture, now the statement is clearly qualified I am happy.
I was not suggesting aircraft hackers could use stuxnet, merely pointing out with determination (and resources) anything is possible. I would not think it beyond the ability of a well financed terrorist group to invent a hack that allows them to disable an aircraft comms/electronics, maybe even screw autopilot and fly by wire (you can't pull every breaker or you can't fly it manually. I agree a bit far to fly it from your seat or the toilets. |
The hand over on this route is usually KL to Singapore on VHF followed by a short period on Singapore HF/CPDLC followed by a hand off to Saigon on VHF. The communications and ATC are, in my experience (25 years) usually excellent. Singapore Radio on HF 8942 is one of the better in the region. Of course, we don't usually keep a listening watch on HF as mostly we use HF Selcal. However, any distress call on VHF 121.5 would have been heard by any aircraft in the area. Even at that time of night there are dozens of aircraft on that airway. If an emergency transmission was made it must have been heard by someone! An absolutely catastrophic flight deck event IMHO. |
@ Cronus
In our hitech world of today, where military sats in their geo stationary orbits around the planet and sophisticated radar heads covering every avaiable square foot of terrain can spot even a mozzie on the loose, with the seas patrolled with nuke subs and sewn with sonoboys that can hear a flatus of a mariner at a distance of 50 miles, how can it be possible for your every day , run of the mill variety type airliner to go into stealth mode for so long. That is what puzzles me most
Probably because the hi res surveillance satellites as used by defence agencies were not operating over this part of the eastern block at the time of the incident and the best images are taken in good daylight. |
Ntsb updates statement on missing b-777 investigation
march 12, 2014 national transportation safety board investigators who traveled to kuala lumpur over the weekend are assisting malaysian authorities who are leading the search efforts for the boeing 777 that went missing five days ago. Investigators with expertise in air traffic control and radar are providing technical assistance to the malaysian authorities who are working on locating the missing jetliner. The ntsb plans no further releases of information on the investigation. |
Quote: Originally Posted by michael0658 View Post The radio horizon at 35,000 ft is about 230 nm for a ground ATC. At its last reported position, this plane was beyond the Line of Sight (LOS) radio horizon for all ATC systems and ground radio. For VHF/UHF I agree. For HF comms, there should have been much longer range/coverage. Question is, was there any guard channel on HF, in that part of the globe, that would been monitored. However, which has not been pointed out anywhere, there is not necessarily VHF coverage for ACARS as SITA and ARINC do not provide full coverage. As Boeing Health Management via SATCOM was not subscribed (most major airlines do not do that due to costs), the airplane was most probably out of ACARS range. |
Interesting ...
Almost the same wording was used in the documents relating to the design of the 787. I use this document in a college course I teach in systems integration. However, they were published effective 2008 -02-01 for the 787. Why so much later for the 777? Was this in response to some incident?
Here is what they said about the 787... SUMMARY: These special conditions are issued for the Boeing Model 787–8 airplane. This airplane will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. These novel or unusual design features are associated with connectivity of the passenger domain computer systems to the airplane critical systems and data networks. For these design features, the applicable airworthiness regulations do not contain adequate or appropriate safety standards for protection and security of airplane systems and data networks against unauthorized access. |
Hypothetical Hello. This is my third attempt to make a post here. Maybe, as I'm new here I'm doing it wrong. I am a licenced engineer, B747. This post attempts to describe, with precedents, a possible single failure that would cause loss of coms, depressurisation and crew disablement due to hypoxia. Precedent: QF30 25 July 2008 Pax oxygen bottle "explodes" tearing a hole in fuselage. Ref: Please google "Qantas oxygen bottle explosion" and view photos of damage. The picture taken inside the fwd cargo compartment shows one bottle missing. there is no evidence of shrapnel damage in the photo. Therefore, no eplosion. The bottle appears to have detached itself from its connections and propelled itself down through the fuselage skin. 777: The crew oxygen bottle is mounted horizontaly on the left aft wall of the nose wheel well structure with the fittings (propelling nozzle) facing forward. This aims the bottle, in the event of a QF30 type failure, directly into the MEC containing all boxes concerned with coms and a lot more. Before all of its energy is spent, an huge amount of damage could be caused to equipment and the bottle could, conceivably, cause a decompression. When the crew respond by doning oxygen mask, there is no oxygen and hypoxia is the next link in this proposed chain of events. This link is entitled "Hypothetical" and is only that. I believe it ticks a few boxes. Hoping this post make it and generates some discussion. Bloxin. Aircraft continues on autopilot maintaining heading and FL set until fuel exhaustion at which point 1st then 2nd engine stops. What sort of descent would ensue? I assume the autopilot doesn't stick the nose down and trim for best glide. |
in an absolute emergency you will transmit on the VHF frequency in use.
For example, these people would possibly have been directed as follows: "Contact Singapore Radio on 8942". However, they would have maintained their previous VHF frequency on their ACP. (Audio Control Panel) Most probably Singapore VHF. On this route we usually hear Singapore VHF almost up until we contact Saigon on VHF. (Depending on your altitude) |
25,000 feet v 40,000 feet
In fact the same article states that pressurised breathing is only required over 40,000 feet:
Oxygen Delivery Systems Continuous flow. This system delivers a continuous flow of oxygen from the storage container. It is a very economical system in that it doesn’t need complicated masks or regulators to function. But it is also very wasteful—the flow of oxygen is constant whether you’re inhaling, exhaling, or pausing in between breaths. This system is typically used at 28,000 feet and lower. Diluter demand. The diluter demand system is designed to compensate for the short-comings of the continuous- flow system. It gives the user oxygen on-demand (during inhalation) and stops the flow when the demand ceases (during exhalation). This helps conserve oxygen. Additionally, the incoming oxygen is diluted with cabin air and provides the proper percentage of oxygen, depending on the altitude. This system is typically used at altitudes up to 40,000 feet. Pressure demand. This system provides oxygen under positive pressure. Positive pressure is a forceful oxygen flow that is intended to slightly over-inflate the lungs. This will, in a sense, pressurize the lungs to a lower altitude, thus allowing you to fly at altitudes above 40,000 feet, where 100% oxygen without positive pressure will not suffice. |
Apparently the Chinese have just released satelite images showing debris floating in the ocean.
Seen the shots on the news - not 100% sure but worth finding these objects... |
There are, however anomalies with the data as presented - for an example, set the time to 17.00 on March 7 and watch what KAL672 (and the neighbouring CCA970) do whilst MAS370 is heading for the Malaysian coast. Perhaps anomalies are to be expected, given that this is unofficial data, but to see 2 reciprocal tracks in the surrounding area of the event under question, AND within a few minutes of the disappearance seems somewhat . . . . odd! Which exactly is the anomaly you see with KAL672 and CCA970 at that time? |
| All times are GMT. The time now is 06:38. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.