Hi Adam,
I thought a good video on why dual engine failure with RAT deploying could be reasonable: [https://youtu.be/8XYO-mj1ugg?si=og2P1G9UeGfCoyWa](https://youtu.be/8XYO-mj1ugg?si=og2P1G9UeGfCoyWa)
Also, a friend of mine received this in a WhatsApp chat, as to a theory:
Here’s my theory, bear with me, amateur plane mechanic over here:
The extreme heat in the forward equipment bay – caused by 40 degrees C ambient temps, close to max weight takeoff roll and the aircraft sitting in full summer sun on sun-baked tarmac for 3 hours – could have triggered a safe state reset of the fuel system controller (FSC) right after takeoff due to overheating.
I did some digging on flightradar24 and noticed this airframe VT-ANB has been consistently failing to send ADS B data during taxi only from Ahmedabad, for weeks. Other 787-8s on the same route don’t have this issue. The lower antenna sits in the forward equipment bay – same place as the FSC – so heat affecting electronics in that area seems plausible to me. Could be a bad antenna, but this airframe only seems to do this at this airport. Could be that the extreme heat here pushes it beyond its working capability.
The plane was fully loaded, close to max takeoff weight. A long takeoff roll, full power, means big electrical load and even more heat in the forward bay. If the forward bay is already hot (maybe 60) right at rotation, the last bit of strain and heat could’ve pushed the FSC over its limit – around 70 degrees C or so. when that happens, the logic card enters may enter “safe state” mode
in safe state, the centre tank fuel pumps will stop because nothing is now controlling them. It’s considered safer in the logic of the aircraft to have the high pressure pumps stop if they cannot be governed. And the wing tank pumps don’t kick in, because they’re also controlled by the same FSC to the best of my knowledge) which is now basically offline.
The engines lose fuel pressure instantly. the electronic engine controls (EECs) detect it and roll back to protect the engines. Then the RAT deploys almost immediately. With no fuel pressure and no thrust, the plane stalls before it can really climb. We get what we see in the video, a plane which takes off fine, loses power almost immediately with no visible damage and has a deployed RAT.
Everything seems to add up to me:
– normal flap setting (no flap lever mistake)
– both engines lose power at the same time explains soft smoke free symmetrical descent
– RAT deploys straight away due to engines idling
– ads-b issues only at this airport, only on this airframe indictate potential heat issue. Ahmedabad stands for wide body’s are all south facing and accident flight was sitting in full midday sun for 3 hours before takeoff.
– max weight contributes to heat buildup as long take of roll generates heat in electrics
– sudden loss of power matches a software error, you can almost see the plug being pulled in the video. Fuel contamination has been ruled out pretty much. Icing isn’t happening in India.
if the FDR shows the fuel controller dropped out after rotation, I think that’s the whole story right there