...] a Plane Talking reader, Paul S, posted a detailed comment on an earlier item about the crash which includes this simple but very practicable suggestion as to how to make it [...

...] make an emergency landing. Others argue this incident is not relevant to the recent disaster. From Plane Talking, written by Ben Sandilands at Crikey Blogs in Australia. It has been reported by The Aviation [...

1…Radio waves propagate VERY badly in water…almost to the point of not propagating. The US Navy submarines use underwater radio at CARRIER frequencies of about 10 Khz and wavelengths of about 30,000 meters (30 Km). This requires enormous towed antennas and huge power at shallow depths…o/k in a nuclear powered submarine. Bandwidth is very limited.
(see: http://en.wikipedia.org/wiki/Very_low_frequency0

2…One of the most useful crash forensics tools is the Cockpit Voice Recorder (CVR). These were strenuously rejected by the pilots unions at first because they expected that management would listen in to cockpit conversations and penalise pilots for what they heard. It was finally accepted on the condition that it would only record a limited time loop, and would have an erase button. The concept that Fifi will continuously transmit all cockpit conversations to Mother in real time for recording and archiving will probably cause pilots to refuse to fly aircraft with such a system.

3…The concept of a floating recorder has neen kicked around for years. At first glance, it could be on the upper skin and released by immersion in water, but that would lead to problems if it rains. Airlines are very reluctant to use any device with explosives in it, and numerous suggestions have been put forward for a sort of torpedo tube device. The fate of AF447 may spur some action.

4…Pingers that ping for a mere 30 days. A simple improvement would be to use a real time clock that causes the pinger to ping about 20 times at very high power on the hour rather than a single low power ping every second. This would enable searchers to get quiet and listen carefully an the hour, and would permit a 22.5 dB increase in ping-power or a nearly 14-fold increase in range without any increase in battery capacity.

5…In order for the ACARS to transmit via SATCOM, it has to have power, so we know that power was still available. Also, the ADIRU’s must be healthy because the SATCOM has to have aircraft attitude etc (Pitch, roll, heading, lat, long.) in order to point its antenna at the satellite. That indicates that the aircraft was moderately intact during that time. Also, in a vertical dive it is unlikely to be able to point the antenna at the satellite. The antenna is an electronically steered conformal device that wraps around the upper curvature of the fuselage.

6…Full time uploading of flight data will be difficult due to the bandwidth required. The last few seconds of data before a crash contains the most useful data, and due to the fact that a full time upload would be delayed, there would have to be an onboard recorder that would have to be found and recovered.

QUESTION: Does anyone khow if large transports like A330 are spun durong flight testing, and do pilots manuals contain spin recovery techniques?? The standard P.A.R.E. may not be best.

Doubts are arising as to whether the four minute transmission interval was necessarily as short as 4 minutes because ACARS depending on how it is used can store some messages for a period and even sent them out of sequence depending on the priority the airline assigns to different categories of maintenance messages. ACARS set ups vary between carriers. Debate about this continues to rage.

I think based on multiple references to the injuries sustained by the victims that the break up was very sudden and clearly traumatic although following a period of some minutes in which the flight was in crisis. Some of the items photographed on the decks of the recovery ships in the main area are from both the front galley area and the rear of the jet, implying little dispersion prior to impact which is contrary to what would have been expected if the breakup was spread over a number of minutes at varying altitudes.

On the other hand, this investigation may well take surprising turns. I wouldn’t rule anything out apart from a bomb blast or fire on board, as there are none of the signs of this on the victims nor on the cabin fittings.

Flotation for data recorders has been suggested over the years. The main issue appears to be the need to have some sort of pressure charge to open a gap through which they can escape. It is quite a dilemma. They need to be located where they won’t be crushed, which is why they are in the tail area, but they also need to be recoverable.

It now seems inevitable that the next step in data recorders will in fact be to replicate their function, and for longer periods, by parallel real time uploads of critical parameters to an archive.

This would have meant that the moment this crash was suspected the airline would have known in sequence and in real time most of the data related to critical functions, including exact location, orientation (was it spinning, climbing, falling, G forces, and for how long etc) as well as the performance of the various systems. The bandwidth and satellites to do this aren’t there yet, they but will be in the future.

...] awaryjnego. Inni twierdzą że tamtem wypadek jest nieistotny w obecnej katastrofie. To ze tekstu Plane Talking, napisane przez Bena Sandilands na Crikey Blogi w Australii [en]. The Aviation Herald, europejski [...

...] make an emergency landing. Others argue this incident is not relevant to the recent disaster. From Plane Talking, written by Ben Sandilands at Crikey Blogs in Australia. It has been reported by The Aviation [...

Continuous transmission of GPS positions are integral to the next generation of air traffic control technology, which is a total redesign and completely different design philosophy compared to current systems. A resource for more information on this is at http://www.faa.gov/about/initiatives/nextgen/

Current ATC is based on radar returns, or reporting and plotting of positions to track, or dead reckoning in lay terms.

The GPS dependant system uses live GPS location reports to constantly track everything, which also changes everything. Australia has mandated introduction of the system from as early as 2013 for some aircraft. We may be ahead of ourselves given the formidable resistance to these changes around the world.

There are several enormous problems with radio signals under water, starting with the need for very long wavelengths, which essentially means large antennas. At more than 3 kilometres down, a crystal clear transmission would involve something the size of a jet, and an order of magnitude or more greater in power, which is also why time is short in picking up the signals that should be emitted now.

Finally, and alas, dropping the black boxes into the depths where there is a complex submarine mountain range and canyons is like dropping them into a rain forest. They can get buried in sediment, slip down gullies and just die signal unreceived. The emphasis in finding the signals will be divided between powerful surface receivers and others towed by submarine devices.