ChrisMaxwell

Incurable engineer, pilot, global entrepreneur, husky owner.

[ChrisMaxwell @maxllama]

@blueorigin Unfortunate. Time to reevaluate the single turbopump design of the BE-4: it's mechanically awkward for an LCH4 engine. Locking the dynamics of methane and LOX onto one shaft is a risk concentration that SpaceX avoids with Raptor.

[ChrisMaxwell @maxllama]

@xAviation Flown on her.
Unforgettable.

[ChrisMaxwell @maxllama]

@Mind_Essentials

[ChrisMaxwell @maxllama]

@AMAZlNGNATURE

[ChrisMaxwell @maxllama]

@airmainengineer @Fahadnaimb The switches are analogue.
The flight data recorder is digital.
In between are... RDC interface, Arinc 664 ethernet, network switches and bunch of software.

We know for sure the switches were in RUN post impact.

[ChrisMaxwell @maxllama]

Where is this screenshot from?

Has anyone seen this video?

This's different from the 2 videos widely circulated. One south of holding point runway 23, other from residential area to west.

Preliminary report says 'CCTV footage obtained from the airport'.

#AirIndiaCrash #787 #boeing

[ChrisMaxwell @maxllama]

@sanjeev__kapoor Indeed! Fuel cut off switches were in RUN post impact.

The fuel switches are ANALOGUE, the flight data recorder is DIGITAL. In between are... RDS interface, Arinc664 ethernet, network switches and a bunch of software.

All we know for sure is they were in RUN post impact.

[ChrisMaxwell @maxllama]

And... the 787 is software-controlled aircraft. Is it hackable? Independent cybersecurity evaluation (2019) suggested multiple vulnerabilities. A horrible thought.
Investigation must consider all possibilities.
> #Boeing787 #AirIndia #FlightSafety

[ChrisMaxwell @maxllama]

We know AIR-INDIA fuel cutoff switches were in RUN after impact. We think, but don't know, they were switched to CUT-OFF 4s after takeoff per report. We don't know if the pilot comment refers to mech switch positions or to alert on the EICAS

[ChrisMaxwell @maxllama]

Yes it's conceivable one pilot sequentially cut off both fuel switches instead of activating gear up lever. But that's a huge stretch for any pilot. Gear progress is actively reported & confirmed by pilots. Release full CVR transcript of crew dialogue.

[ChrisMaxwell @maxllama]

@21WIRE

[ChrisMaxwell @maxllama]

The bottleneck for solar growth is energy storage, esp. battery (BESS)

To reach 6,000TWh solar annual by 2030 (18% of global power), installed BESS needs to be at least 4TWh daily capacity (>1,500TWh annual)

We need 10X 2025 BESS capacity which is 3X current 2030 global BESS projections

[ChrisMaxwell @maxllama]

The bottleneck for solar growth is energy storage, esp. battery (BESS)

To reach 6,000TWh solar annual by 2030 (18% of global power), installed BESS needs to be at least 4TWh daily capacity (>1,500TWh annual)

We need 10X 2025 BESS capacity which is 3X current 2030 BESS projection

[ChrisMaxwell @maxllama]

The bottleneck for solar growth is energy storage, esp. batter (BESS).

For solar to reach 6,000TWh annual by 2030 (18% of global power), installed BESS needs to be at least 4TWh daily capacity (>1,500TWh annual).

We need 3X current 2030 BESS projections and 10X growth from 2025 capacity.

[ChrisMaxwell @maxllama]

@grok, whats your opinion on this?

[ChrisMaxwell @maxllama]

Run the APU on take-off as precaution>>

787 has 6 main fuel pumps, all electrically powered by 230vac bus and 4 engine-driven 230v generators
If 230v power fails, fuel pumps stop and engines reduce power to gravity feed, or stop. RAT deploys but does not power engine fuel pumps

APU could, but only after it's started and fault cleared

#boeing #airindia #787crash #aviaitionsafety #ntsb

[ChrisMaxwell @maxllama]

@implausibleblog G7
8 members
9 attendees

They have some basic issues.

[ChrisMaxwell @maxllama]

@gunsnrosesgirl3

[ChrisMaxwell @maxllama]

787 electrical fuel system.

The 787 has a complex electrical system with over 1000 load circuits. The engine fuel pumps are electrical (there are six of them), all powered by the main 235VAC bus, which is in turn powered by the engine driven generators. It can also be powered by the APU (auxiliary power unit). There is also a single 28VDC fuel pump which supplies fuel to the APU. The APU can be started from the RAT (ram air turbine) or battery. In the event of a serious problem with the main 235VAC power bus, power would be lost to the engine fuel pumps. The RAT should deploy automatically on major loss of power. (It is not confirmed whether the RAT was deployed pre-crash). Bringing the APU online and isolating the fault could potentially restore power to the engine fuel pumps, but would take time.

There is a video posted online by a passenger on a previous flight of the crash aircraft. It alleges that there were electrical problems with this aircraft. In particular, the ECS (environmental control system) cabin air recirculation was not working, and the aircraft cabin was very hot. Now the issue could have been due simply to a lack of ground power, or non-operation of the APU. However, the ECS air recirculation is powered by the 235VAC bus (through a transformer rectifier), the same bus that powers the engine fuel pumps. It could be just coincidental.

Until fuel delivery is ruled out, it might be prudent to issue a directive to run 787 APU's during takeoff.

The solution is technical; the tragedy is human. Peace and comfort to everyone touched by this tragedy.

#airindiacrash #flightsafety #boeing #787crash #jenniferhomandy #toddinman