This was interesting, thanks. For others: "inerting" is process of keeping fuel tanks filled with inert gases like nitrogen to decrease the change of a fuel tank explosion.
The reason the FAA considered fuel tank inerting in the first place is because of a 1996 crash of a 747 that killed 230 people[1], and which is thought to have been avoided had the tanks been inert[2]. Other 747s were lost to the same issue, such as the ULF48 that crashed in 1976 killing all aboard[3].
To answer your question, no, the 747 is not "safe". No aircraft ever made is "safe". They will all crash and kill people given sufficient flight hours. The question is what we consider acceptable risk, those standards change over time as technology improves, and as regulators phase out older models by sunsetting certain exceptions.
As that's done older aircraft either need to be retrofitted, or sold to jurisdictions with laxer rules.
I hadn't read the Wiki article about inerting systems up until now. It's interesting to me that the prediction is interting systems will prevent 8 of 9 expected wrecks in the next 50 years.
I'd argue that modern aircraft are safe especially after you factor in how many hours these things fly compared to the number of deaths. Of course, air travel has become significantly safer over time. Check out the early history of 727 hull losses. While the 747 had a number of poor designs (especially early on), the deadliest 747 wrecks were due to pilot error (e.g. Tenerife).
I appreciate your answer and the informative links.
No aircraft ever made is "safe". They will all crash and
kill people given sufficient flight hours. The question
is what we consider acceptable risk,
Let's give our fellow HNers a little credit, shall we?
When the other poster asked if 747s were "safe," do you really think they meant to ask if 747s were literally indestructible? Or do you think the other poster meant "safe" as in "safe, compared to other aircraft, which are things that any reasonable human being understands can have accidents from time to time?" I really believe it was the latter.
Nobody thinks airplanes are indestructible, but it is counteractive to those not familiar with commercial aviation that not only is the market for licensing new airframes regulated, but that older airframes are expected to be retrofitted to the latest safety standards or lose their license.
This isn't how e.g. trains, buses and even taxis are regulated. E.g. I believe in most of the western world you could still operate an antique car without seat belts as a taxi.
This is how I read the GPs comment of "I take it 747s have been safe up til now". The only way the bus/train/taxi in my example would lose its license is if it could be shown if the vehicle didn't adhere to the safety standards at the time, whereas the same isn't true for airplanes at all due to how the FAA & EASA regulate them.
Theres a lot of speculation about TWA Flight 800 so thats pretty interesting. I some how stumbled on CPAN one night and the guy that wrote TWA 800 Crash Cover Up Conspiracy was giving a talk. Listening to the commenters afterwards, all were either engineers, pilots, or former air force and seemed to be in agreement with the author. Theres a TWA Flight 800 documentary as well.
So what. You can find more engineers and pilots who don't believe it was a conspiracy. The human mind tends to invent patterns where none exist in a vain attempt to make sense out of chaos.