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.
IGARI is well inside ATC VHF coverage of Lumpur, there may be a small occasional gap (a few minutes) until HCM can be reached.
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.