Ask The Pilot

[jb747]

I guess the answer is to never trust anyone who agrees with you.

 

[mjt57]

I guess the answer is to never trust anyone who agrees with you.

Sorry, that's wrong....

 

[Quickstatus]

Why didn't Boeing use Chemical O2 generators in the B747-100-400 for passengers?

I understand the 737 had a hybrid oxygen system
- oxygen tanks for flight crew and chemical generators for passengers

 

[exLXCXFF]

This is a scary one: Accident: Vietnam B789 at Munich on Aug 15th 2026, late rotation, tailstrike, runway overrun, tyre damage

 

[AuSammy]

This is a scary one: Accident: Vietnam B789 at Munich on Aug 15th 2026, late rotation, tailstrike, runway overrun, tyre damage

To an untrained eye looks like tyre damage least of their issues (and probably caused from hitting lighting arrays) beyond end of runway)

 

[jb747]

Why didn't Boeing use Chemical O2 generators in the B747-100-400 for passengers?

I understand the 737 had a hybrid oxygen system
- oxygen tanks for flight crew and chemical generators for passengers

Hybrid systems are probably the most common. As far as I know, all crew system are pressurised gas, presumably because at very high altitude it actually needs to go to the mask under substantial pressure. Called pressure breathing, and it's extremely uncomfortable.

But back to the base question, it would be a question of duration. Chemical systems give up to around 18 minutes, where the pressurised systems can be measured in hours. There are many cases where going to 10,000' isn't possible due to terrain, so the initial descent could be constrained to as high as 20,000'. You can also come up with examples where, due to range issues, you can't cruise at 10,000'. Being able to stop at a higher level (in the order of 15,000-20,000') could make the difference between getting to an airfield, or going for a swim.

 

[jb747]

This is a scary one: Accident: Vietnam B789 at Munich on Aug 15th 2026, late rotation, tailstrike, runway overrun, tyre damage

To an untrained eye looks like tyre damage least of their issues (and probably caused from hitting lighting arrays) beyond end of runway)

The far end of the runway tends to be an unfriendly place, and best not visited. There are no clues in the video. Configuration looks ok. There doesn't appear to be any elevator input until right at the end, so perhaps they were having a sleep.

 

[Brissy1]

I guess the answer is to never trust anyone who agrees with you.

Agree