David Maximilian Walker was born in the city of Anchorage, Alaska. His parents were both scientists who worked at the large stellar observatory just outside the city, and it was through them that David developed his fascination with space. Being raised by astronomers and spending his nights under the Alaskan sky, which in the wintertime would often play host to the Northern Lights, influenced young David's decision that what he wanted to do with his life was travel among the stars and explore the final frontier.

His best chance to do so was in Starfleet, but his dream was temporarily derailed when his first application to Starfleet Academy was rejected. David persevered, determined to enlist, and he was successful with his second application in 2377. Specializing in flight operations and astronomical sciences, he proved to be a talented pilot and a model cadet, and graduated in his class' eleventh percentile.

Though he expected to become a helmsman following his graduation, David was instead assigned to the USS Zealandia as a pilot in the new Starfleet Starfighter Corps. Although initially upset by this, as a career in flight control was better suited to the command track, David quickly grew to love the life of a fighter pilot which, on the whole, tended to be much more easy-going than a Fleeter's. David gradually began to forget his desire to become a starship captain, quite comfortable with his new role as a pilot in the SFFC.

In November 2382, David's squadron was engaged in a minor skirmish in which his fighter was heavily damaged. He managed to eject before it was destroyed, but in the process he suffered a serious head injury that rendered him comatose for a week. After waking from the coma, David retained all of his motor functions, but the damage to several blood vessels in his brain was such that, even after surgery, he would be unfit to continue his duties as a fighter pilot, due to the likelihood that the physical stress from high-G maneuvers could damage them further and possibly cause them to rupture.

Disappointed, but still determined to remain in Starfleet, David transferred to Navigation, and he returned to the Zealandia as a flight control officer. He wasn't entirely discouraged, however, as this would allow him to once again pursue his original goal of commanding a starship. David remained aboard the Zealandia for a few more months before he learned of an opening for the position of Assistant Chief of Flight Control on the USS Galaxy. Though he wasn't unhappy with his current assignment, he couldn't let this opportunity to further his career slip away, and he applied for the position, for which he was quickly approved.

David's ambition isn't difficult to recognize: he wants to command a starship and he intends to see that goal through.

However, he understands that getting there is a long, difficult road that requires years of exemplary service and a clean record, so he tries to keep to his best behavior when wearing the uniform. Immensely sure of himself and his abilities, he practically exudes self-confidence; this, combined with the bit of roguishness he developed during his time as a fighter pilot, has been known to land him in trouble, but so far he's been smart enough to avoid getting himself into any career-threatening situations.

When not on duty, however, the spit-and-polish, gung-ho attitude vanishes. David knows how to relax and have fun just like any other fighter pilot. He loves the outdoors and playing sports, card games, and his custom-made Terran guitar, and he is not shy when it comes to interacting with other people. He generally makes it a habit to get to know the pilots first before anyone else, though now that he wears a red collar instead of a white one, this may be easier said than done.

His career in the SFFC has also influenced the way he operates the helm, as he still has the instincts and attitude of a fighter pilot and often tries to fly the ship like it's a starfighter. This method has worked surprisingly well for him, particularly in combat situations, but people have been known to complain about David handling the ship more roughly than is actually necessary.

David's former doctor aboard the Zealandia has said that his injuries will eventually heal completely, and that whether or not he ever gets back in the cockpit will be a mental issue, not a physical one.