Picture it; Lakehurst, New Jersey, May 6th 1937. The LZ-129 Hindenburg arrives on her first North American trip of the season. Crowds gather to watch it land, newsreel cameras are rolling, and everything goes as planned. The Hindenburgh doesn’t burst into flames. Passengers disembark without incident, and after the layover she heads back to Germany with a new group of passengers. How would this effect the fate of rigid airships? How long would they last? Germany was basically the only country still flying them at point (the Los Angeles was mothballed, but not yet scrapped). They were also ran the only regulary schedualed transatlantic passenger air service ('till Pan Am launched the Yankee Clipper in '39).
In the short term the Hindenburgh would continue her flights between Germany, the US, and Brazil. Next season her sister, the Graf Zeppelin would be retired to make way for the Graf Zeppelin II. I imagine passenger service would continue right up until the outbreak of World War II. Then they’d be mothballed for the duration (unless the Nazis used them for more propoganda flights). They’d probally get broken up for metal anyway as the War drove on and Germany’s situtation deteriorated.
Would zeppelins have made any sort of comeback after the War (Germany wouldn’t be in any position to restart passenger service)? We made alot of advances in fixed-wing aircraft during the war (not to mention all the runways all over the planet that got built). Would there have been any attempt to use them militarly durring the War? I could see the USN maybe taking Los Angeles out of mothballs to augment it’s blimp program. Even if they couldn’t compete with planes would rigid airships continued to have a niche used to the present day? Would we have seen an attemp at reviving passenger service by now like how ocean liners were reborn as cruise ships?