This article is about an in-game mission. For the in-universe event, see Operation Early Bird.

Lifeline is the fifth campaign mission of Ace Combat 04: Shattered Skies.


Comberth Harbor, home of the Aegir Fleet, is completely dependent on a single petrochemical complex for its fuel supply. The complex consists of a land based oil refinery/storage facility, and an offshore oil-drilling platform. Your mission is to go out and destroy, or at least damage, these sites. Our objective is to reduce production output of this complex to 20% or less. By cutting off the port's fuel supply, we will delay and disrupt the combat deployment of the Aegir fleet.



In the first part of the mission, the player is tasked with attacking the oil refinery by the coast to the west and the oil platforms on the sea to the east. The mission's score requirement depends on the player's selected difficulty:

  • Easy or lower: 1,600
  • Normal or higher: 2,000

The player must surpass the point threshold within ten minutes to advance the mission.

Mission Update

AWACS SkyEye informs all allies that the Yellow Squadron has arrived, and orders them to disengage and return to base via the Return Line. The Yellows cannot be shot down, so the player should fly south to complete the mission.

Enemy Lists

Standard Units

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Special Units

Unit Points Count Notes
Icon-AirEnemy MiG-29 "MRKOS" 240 1 [note 1]

S Rank

An S rank for this mission requires 4,000 points on Normal difficulty or above (3,100 points on Easy difficulty or below).[1][2]


The enemy lost 5 million barrels of reserves and the ability to process 250,000 barrels of crude oil daily. The Aegir Fleet is effectively immobilized and no longer a threat. Unfortunately, our losses were high as well. We now rely on your skills more than ever to compensate for our losses.



  • Following the release of Ace Combat 04, some fans reported that they were able to either hit or shoot down a Yellow during this mission, widely believed to be impossible. The game's director, Hiroyuki Ichiyanagi, expressed his surprise upon reading such claims, realizing that they hadn't made the Yellows as invincible as they had hoped.[3]


  1. The player must have completed the campaign, and must be playing on Normal difficulty or higher. Mrkos is located just west of the oil refinery.


  1. Ace Combat 04: Shattered Skies - Official Guide Book, pages 038-039.
  2. Ace Combat 04: Shattered Skies - Perfect Guide, pages 074-077.
  3. Ace Combat 6: Fires of Liberation: Page 4. GamesRadar+. Published on April 4, 2007. Retrieved on December 15, 2016.
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