Satellite data in the ITCZ
Hello all,
I've been following this thread since shortly after the accident happened. As a frequent flyer (100K+ miles a year on UAL alone) I have an amateur interest in aviation. My professional interest is in satellite observing systems, both on the development side and regarding technical and regulatory matters involved in getting the data from them out to the users. I am posting here in an attempt to find out whether there is anything that the satellite community in particular can do to help prevent a repeat of what happened here. My apologies in advance if this post is out of line with the purpose of the board.
Reading this thread has been very informative for me, so thanks to all of you who are sharing your knowledge with us. I understand that we still do not know exactly what transpired, and I don't have the qualifications to add to the speculation or hypothesizing about it. Without going into details about that or about who might be at fault, I will for now assume that weather played a primary role. My assumption is very simple: For some reason AF447 ended up in the middle of an active thunderstorm in circumstances that exceeded the combined capabilities of the aircraft and its pilots.
For areas beyond coverage of ground-based radar networks, the best source of information about convective weather is generally the geostationary satellite system. AF447 went down somewhere near 2 deg N, 30 deg W, in an area for which satellite coverage is provided by both the US (GOES-E operated by NOAA/NESDIS) and Europe (EUMETSAT's Meteosat-9). Being of a more recent generation, the Meteosat-9 imager is slightly more capable (12 channels, 15 minute repeat cycle) than the GOES imager (5 channels, 30 minute repeat). From cross-referencing the cloud-top temperatures measured from satellite with the ACARS messages, we now seem to believe that AF447 was in an area of (surrounded by?) Cb's topping out at 50,000+ ft when things started to go wrong. Since these satellite data are processed and disseminated in real time, in principle there ought to have been a way for the pilots themselves to know that, possibly and hopefully before actually finding themselves there. Assuming now that this was not the case, there are two possible reasons: 1. The data aren't acquired and processed fast enough to keep up with the convective development, or 2. The data are not made available to the flight crew.
Concerning the former, it is true that neither of these two satellite systems have image repeat rates meeting the formal requirements adopted by the World Meteorological Organization, namely 10 minute (or better). This can obviously be a problem for very rapidly developing systems and that may or may not have been a factor here. The next generation imager to be flown by the US on GOES-R in the 2015 time frame will - depending on scan mode - be able to provide full-disc imagery every 5 minutes. However, unless these data in some form actually make it all the way to the flight deck they may not be of much help in the kind of situation we are discussing here.
So my questions to those of you who fly transoceanic routes in areas of convective weather are the following:
1. Do you have in-flight access to geostationary satellite images (or to products derived from them, such as instability indices or cloud top temperatures)?
2. If the answer to 1. is yes: Do you consider this useful for instance when crossing the ITCZ? If not, what would you like to see changed in the data you have access to?
3. If the answer to 1. is no: Why don't you ? Is it a communications/aircraft systems issue? ... a data policy issue? ... due to fear of information overload?
Thanks for bearing with me here.