It's a question that stumped Green Lantern fans for years: why exactly was Abin Sur piloting a spaceship if he had a Power Ring? A couple of retcons didn't just fix up this plot hole, it helped expand the mythos in a very satisfying way.
The secret origin of Green Lantern is one of the most well known DC stories. Abin Sur, the original protector of Sector 2814, was gravely injured and forced to make a crash landing on planet Earth. After scanning the world for a suitable replacement, his ring settled on test pilot Hal Jordan as the newest Green Lantern, and the very first recruit from Earth. Hal quickly realized the power he literally held in his hands. His new ring enabled him to create amazing constructs, communicate with other alien species, and, interestingly enough, fly through outer space. The fact that the rings make interstellar travel a possibility for their users makes it all the more strange that Abin Sur perished in a spaceship.
Thankfully, the story "Tygers" by Alan Moore and Kevin O'Neill in Tales from the Green Lantern Corps Annual #2 helped explain Sur's final moments. After traveling to the planet Ysmault, Sur meets a villain of the Guardians of the Universe, Qull of the Five Inversions. Though imprisoned by Sur's leaders, the demonic alien promises to answer any three questions Sur wishes. After Sur sees a demonstration of Qull's prognostication ability, the Lantern asks what danger awaits him in the future. Qull reveals that sometime soon, Sur's ring will fail him at a critical moment. Qull even plants an idea in Sur's head that his ring could run out of energy in space, leading him to make the decision to use a ship for long, interstellar journeys.
This particular retcon would later be revisited and help expand Green Lantern’s lore. Geoff Johns and Ivan Reis' Green Lantern #30 shows a paranoid Abin Sur transporting the future Red Lantern Atrocitus in his ship. However, the fear that has seeped into Sur's mind weakens his willpower and allows the prison-construct holding Atrocitus to break. Atrocitus uses his freedom to gravely injure Sur, thus setting up the classic origin all DC fans know.
Alan Moore's addition to the Green Lantern mythos helped patch up one of the most glaring gaps in logic in the DC Universe. And his retcon paved the way for Johns to build on the legacy of Green Lantern himself. Johns' run dealt with how powerful feelings can influence a Green Lantern. Having Sur die as a result of being corrupted by fear is a natural growth of the story Moore and Kevin O'Neill told. It rationally explains Sur's strange decision and emphasizes that his ultimate fate was actually a self-fulfilling prophecy. The retcon didn't just fix a plot hole, it made the origin of Green Lantern much richer.