SamAsama
Retired F4: In two posts within a short time you strongly opine that weather was not a contributing factor. Though I have re-read the posts several times I cannot follow your logic. Please try again to convince me that Wx could not be a factor (whether the aircraft was IFR / IMC; IFR / VMC; or even VFR. I can cite many accidents / incidents worldwide wherein Wx was a contributing factor in all of the above combinations of flight conditions.
Thank you for your interest in my oppinion in regard to the probable or existing weather in the accident area.
Iīve never flown in indonesia, but marginal weather for flying can be found anywhere in the world, especially also in central and northern europe.
Aircrews flying modern equipped transport aircraft (and by the way that applies as well for GAT and MIL aviation) are expected to handle the preparation and execution of a flight under all kinds of weather and flight rules to the max extent possible. That means plan according the weather forcast and execute the flight in accordance with the regulations implemented for IFR or VFR flight rules under observation of the actual encountered weather situations.
In short, if you plan to fly VFR, than do it only when the weather will allow it. If you run into unsuitable weather under VFR, then terminate flying VFR and reopen an IFR flight plan. If you are on an IFR flightplan and intend to continue under VFR, it is your responsibility to make sure, that the weather is apropriate to do so. Itīs the pilots responibility to orient the planing and execution throughout the flight by respecting the actual weather situation.
We are looking at a flight with a planned flighttime of less than one hour, therefore the forecasted weather should be pretty close to the existing one, including the local weather developements in hilly terrain like you describe it very well. There should be no surprise factor there, if the flight planning and weather briefing was done in accordance with existing rules (which i dont know from indonesia, but they shouldnīt be that different).
Those weather phenomena you describe so well will only influence a flight under visual flight rules. Under IFR itīs no need to see anything except for the final moments of the landing. Only enroute hazard would be thunderstorms , which can be avoided by correct operation of the onboard WX radar.
As far as we know at the moment (that might change, when the CVR or the FDR reveal anything different) the flight was conducted under IFR and the crew requested an descent below MSA / MORA, and ATC granted that descent. Wether that descent was requested and conducted under IFR rules in IMC or VMC or wether it was under VFR / VMC does not change the responsibility of the crew to not descent below the MSA / MORA under IFR/ IMC or to stay well clear of clouds and terrain when operating in VMC.
There might be reason for the crew to descent below MSA /MORA and not be able to maintain VMC close to the ground, but there is none known until now, and i canīt think of one. But iīm open minded, if you see reason in the actions of the crew. The argument, that weather itself was a contributing factor in other accidents is noted and accepted. Icing, turbulence, extreme headwinds, suddenly closed airfields, runway contamination due to precipitation comes to my mind (there sure might be others as well).
But bad planning and bad execution does not make up for your suggestion, that the weather could be a contributing factor for the tragic outcome.
They just had no sound reason to be between those mountains (neither in VMC nor in IMC) below the MSA / MORA, and it was not the weather that led them down there.
Thatīs no condemnation of the crew, there might be other factors which led to the accident, which we donīt know yet (i.e. technical issues, human factors), i only objected the theories concerning weather and malfunctioning terrain avoidance gadgets being causes or contributing causes to the accident.
Just for the record, that is my personal oppinion, and you and others are entiteled to a different one.