I Think I Saw MH370 - Cruisers & Sailing Forums
Post #1 SaucySailoress No mention of flames but I think it's a reasonable inference?

A common misidentification
 

I thought it might be pertinent to point out that fireballs, missile launches, flaming meteors, spaceships reentering, planes on fire trailing smoke etc are quite regularly attributed to normal passenger jets leaving contrails in early morning or late afternoon sun. A classic example was the infamous Los Angeles "Missile" with "flaming tail" which in fact was a ups transport with bright sun reflection and a contrail. Los Angeles Missile Contrail Explained in Pictures - Contrail Science » Contrail Science
Similarly an airliner flying over Peru misidentified as a fireball. https://www.youtube.com/watch?v=hBKHkWw0oWg

With supposedly expert commentators like ex-airforce commanders claiming such things to be missiles or fireballs when they are in reality just afternoon/morning light effects on normal jets , it would probably be premature to ascribe too much importance to an inexpert observer on a yacht reporting an orange light and a smoky trail on an aircraft in early morning.

It could be anywhere on any radial from where the last ping occurred to where the next ping would have occurred. That's potentially a long distance. We just don't know what happened after the last ping. We don't even know if the satellites data is reliable. If they can stuff up a search by incorrectly identifying false pings, what else can they stuff up? How can we have confidence in anything these so called experts undertaking this search tell us?

That would require another hour of fuel. The time where the next ping would have occurred is irrelevant, only the fact that it did not occur, and that the last handshake was initiated from the airplane and was incomplete.

I don't see any reason to doubt the reliability of the Inmarsat logs. The real question is how accurate the BFO and BTO values are. The notes that precede the logs in the Inmarsat release discuss the sources of several inaccuracies.

Heyits007

Inmarsat data checked by AAIB before handing to malaysians then checked again by them an NTSB sources, it included checks against other malaysian 777 and earlier data from the same airframe.

WHAT ELSE DO YOU WANT THEM TO DO? please tell us what they have missed!

The TPL pings

1) In the area they were expected
2) Died at predicted battery run out date
3) Off frequency

2 out of three seem good, so sensible to try bluefin

I take it if you had been in charge you would have said ok guys forget that crap, lets look somewhere else - anyone got a map and a pin.

What if they had 30 to 45 minutes of fuel rather than an hour? I come back to my original point. If experts can't even get the ping detection reliably, after spending massive resources in the search, it's difficult to have a great deal of faith in other aspects of this search. Perhaps they will get lucky, but eventually there will come a point in time where they will have to question the worth of investing further resources into this.

as he is new might worth explaining

a) last ping not on the hr
b) initiated by aircraft
c) probably due to RAT (for a very short period) powering up after both engines stopped

That's what you need to explain

Pontius if A,B or C wrong please correct

Not at all. If the TPL was that easily fooled, especially when they seemed so confident in the pings, it's difficult have a great deal of confidence in the rest of the search operation. Even the partial ping does not seem to have a conclusive published official explanation. It's quite speculative here and elsewhere. They might keep searching, but it seems there will be many unanswered questions. Seems to be much conjecture as to what actually happened.

HeyIts007. Are you trying to justify an end to the search? If so, argue the point, don't berate the experts. They might get some things wrong along the way but what do you expect of a complex investigation into a complete mystery?

A number the realtives of missing pax are in the process of launching a reward offer of $5m using the Indiegogo web site. Suspecting a cover up on the part of the authorities, they are hoping this sizeable reward will entice a whistle blower to crawl out of the woodwork.

Similarities to the Aerolinee Itavia 870 crash of 1980 seems to be developing.

Once the second engine failed (together with its generator), due to fuel starvation, the only fuel left may well have been in the APU feed line from main tank to the APU in the tail.

The on-board logic within the electrical system, with both generators off line, is automatic APU start so we may well have seen the "aircraft initiated ping" when the APU generator came online, all be it briefly before it also ran out of fuel.

The power from the RAT most certainly would not have powered the satellite system.

Regarding the credibility of INMARSAT data
 

I have just seen an interview with a vice president from INMARSAT - after listening to this I must say that I have regained considerable confidence in the correctness of the data presented by INMARSAT in the case of the missing MH370.
Link:
MH370: Is Inmarsat right? - CNN.com

Two queries:

Woodpecker - is the 777 system such that an 'automatic' APU start would automatically bring the APU gen on line?

Anyone - have we seen any estimates of a/c radial groundspeed from the BFO data from Inmarsat? This would give the minimum g/s at any point, and as the a/c travels further from the satellite should approach actual g/s.

I'm not sure I understand your question. The aircraft radial groundspeed to the satellite is determined from the BTO (Burst Timing Offset). It is equal to the distance between two successive arcs divided by the time difference between those arcs. The north-south component of the aircraft velocity can be calculated from the BFO (Burst Frequency Offset). The accuracy of both calculations is critically dependent on the precision that the true BFO and BTO values are known (*), and that is the reason for the uncertainty about probable trajectories.

(*) EDIT: That applies in particular to the BFO value. The notes on page 2 of the Inmarsat release explain the factors that may affect the accuracy.

Pretty well anything, after all they are human. Thats why they share the data with various competent research groups and agencies to get independent analysis. This takes time and they have to have to search on the best evidence they have at the time. It doesn't help they have to report on every little thing on a daily or shorter basis else they get accused of hiding information

Thats up to you and your understanding of the process and the challenges involved. As for me I'm more than happy with the effort they have put in considering all the challenges.

So what do you think does "add up?

FWIW a clean 777-200 at light weights descending at say Vref 30 +80 (min clean) possibly needs an ROD of around 1000fpm/16 fps with engines at idle to a maintain min clean IAS. However if you chuck all the rules about buffet margins and min FCOM speeds out of the window due to "Force Majeur"/pilot incapacitation then low RODs become very credible and I think extrapolating "time to splash" from some (alledged ) datalink burst becomes highly speculative.

(777 driver with X thousand hours on type, so no doubt about to be moderated out)

Why so little? They can safely offer $100 mln - the result will be the same.

BOAC and Gysbreght.

From the Inmarsat filed data you have for each ping: a time H, a BTO (a length of time), a BFO (a frequency value). Please, reread the first page of the "raw data".

The BTO is only used to know at which distance R is the a/c from the satellite at the time H. From this distance R you can know that the a/c is somewhere on a circle. This circle is the intersection of:
- The sphere centered on the satellite at the time H and with a radius R,
and
- the "sphere" centered at the Earth center and which has the radius of the Earth plus the a/c altitude. This "sphere" is not a true sphere because the Earth is not perfectly spherical, so the circle is not a true circle.

The BFO comes from:
-1- the speed of the a/c relatively to the satellite,
-2- the speed of the satellite relatively to the a/c,
-3- the speed of the satellite relatively to the Earth station,
-4- an "error" from the a/c component which communicate with the satellite,
-5- the position of the satellite relatively to its theoretical fixed position above the equator.
#3 and #5 are perfectly known at whatever time. #4 is deduced from the data of the begining of the flight and from older flights of the a/c. So the global effect of #1 and #2 could be known from the filed BFO.

Theoreticaly, the a/c compensate the BFO from its own speed relatively to the satellite (#1). But this compensation is based on a fixed satellite. So the compensation the a/c mades is wrong when the satellite is not at its theoretical position. Say this value is F1.
The other useful component of the BFO is the one from the satellite speed relatively to the a/c (#2). Say this component value is F2.
Only the sum F1 + F2 is known. It results from the measured BFO after two corrections: 1) for BFO due to the satellite speed relatively to the Earth station and 2) for the "error" from the a/c component deduced from BFOs at times when the a/c position was known before take off.

For a given point on the circle, you can know F2 (because the satellite speed value and direction are perfectly known at the time H). So you can deduce F1.
But, you can't deduce a speed of the a/c from F1, only a "couple" [speed + direction of flight]. There are an infinity of couples which are in accordance with F1, thus with the BFO, but you have a minimum speed (flight direction exactly away from the satellite) and a maximum angle between the direction of flight and the line of sight of the satellite given by the maximum speed of the a/c. This error is also very small, so the incertitude about the "couple" is pretty large.
Fortunately, there are two other constraints:
- you have to reach the next circle at the right time (the time of the next ping),
- the point reached has to be in accordance with the new BFO at this time.

If you knows the first point (from primary radar position extrapolation), it is easy to find a flight path in accordance with all data, after making suppositions about the speed of the a/c (for each one, different headings...).
If you dont't know the first point, you have to compute many hypothesis (about the first point) to find credible flight pathes.

Shadoko wrote
This is an important point. Further comments:

(1) Conceptually, it is tidier to separate out:(2) The BFO correction value is apparently derived based on measurement of the frequency deviation of the incoming signal received from the satellite. The idea is that the a/c system pre-compensates for Doppler shift such that the signal received by the satellite appears at the nominal channel frequency.

Doesn't the Power Supply Assembly use a dedicated battery to prevent power interruptions during power source transfers?