Ah, I see. Really should read before jumping in. XD Sorry. Was just really interested. XP
Yes, your input is most welcome. Anyone is welcome to take part in these discussions. And I think you're right that they were somewhere around Sulawesi.
Also the tv report on pg 60 states that Tintin and friends were found only 200 miles off their course; there is no way they could have got to the Celebes Sea as they were 200 miles from Sumbawa
Yes, that makes it a bit of a conundrum. Having looked at map of the region (always useful!) it doesn't seem possible. As you say, the places they flew over made them pretty much on course to Australia. On page 12, Skut says they'd just passed Lombok and were heading to Sumbawa. And on page 14 (directly after the hijacking takes place) Spalding reports they were over Sumbawa, just before they ducked down out of radar range. So that's almost a straight line from Jakarta towards Darwin in Australia. Yet the TV report states they were "found drifting in a dinghy more than 200 miles off their scheduled route", so how could they have been found in the Celebes Sea?
There's another clue: on page 16, a little after the plane had been hijacked, it says "ten minutes later" (frame 2) before they reach Pulua-Pulau Bompa. They may have flown for a little longer than ten minutes, so add a couple of minutes for page 15 where the plane changes course. Carreidas mentions on page 8 that the jet can fly at 1,250mph (at a cruising speed at 40,000 feet), so let's assume it was slightly less at a low altitude, say 1,200mph. Flying for ten minutes at 1,200mph would take them 200 miles.
Maybe Hergé was having an off day or didn't care which Sea it was (very unlikely, given his usual accuracy), so we could just ignore the Celebes Sea reference. It seems likelier that Pulua-Pulau Bompa was around 200 miles from Sumbawa, and probably along the archipelago given that it's on the tectonic rim with the volcanoes dotted along it, so perhaps in the Flores Sea?