I did this on Space Suits You, Sir. Before piloting the jet, jump off the bridge as Batman and start gliding by holding the jump button
Alternatively, you can go to Oa by picking a flying character and flying to the top of a giant Green Lantern logo, then switch to Batman and glide until you get the achievement
To reach Oa, complete the Green Lootern's "Permission to Launch" Quest in the Watchtower to enter the Moon Base. From there, you'll need 30 Gold Bricks and have completed one of the Lantern planet levels to construct the portal that will send you to Oa. The portal itself can be found outside the Moon Base. You can reach it through the vent inside the base or by simply walking outside and looking for it.