Slug Copter is a good attack plane, similar to Pegasus in it's attack attributes, which are better than the S-Wing, Storm Wind, and Shadow Airship, but not as strong as the Ice Dragon or Arctic Sleigh. Unfortunately Slug Copter was only available during the Metal Gear Crossover events from mid-September 2019 through May 2020, and cannot be purchased or otherwise acquired in any way at this time.
Recommendation:
Slug Copter is a decent attack plane. Hopefully you were able to purchase it during the Metal Gear Crossover period.
Recommended Gears:
It's worthwhile to put decent attack gears on your Slug Copter. There is a matching gear set for the Slug Copter, but I don't believe it has any special abilities when paired with the actual plane:
- Superalloy Slug
- Blade of Champion
- Wild Roar
- Blackbat
- Nature Force
- Christmas Gold Bell
- Christmas Silver Bell (Gold)
Where to get Slug Copter Spare Parts:
Slug Copter was only available during the Metal Gear Crossover events from mid-September 2019 through May 2020, and cannot be purchased or otherwise acquired in any way at this time.
You need 1 of each Spare Part to make a whole plane:
 |
Slug Copter - Cannon |
 |
Slug Copter - Empennage |
 |
Slug Copter - Fuselage |
 |
Slug Copter - Propeller |
Initial Core Attributes:
- Initial core stats:
- Armoring I: 5400
- Firepower: 5400
- Energy:0
- Initial Chip slots: 11
Air Force Attributes:
The Attributes of the Slug Copter are primarily focused on Attack:
| Plane | Attribute | Steps | Buff | Modifier | Usage |
|---|---|---|---|---|---|
| Slug copter | Artillery Firepower I | 5 | Artillery Attack | +20% | Attack |
| Slug copter | Artillery Firepower II | 5 | Artillery Attack | +45% | Attack |
| Slug copter | Commando Firepower I | 5 | Commando Attack | +20% | Attack |
| Slug copter | Commando Firepower II | 5 | Commando Attack | +45% | Attack |
| Slug copter | Copter Firepower I | 5 | Copter Attack | +20% | Attack |
| Slug copter | Copter Firepower II | 5 | Copter Attack | +45% | Attack |
| Slug copter | Commando Protection | 5 | Decreases damage taken for all your commandos. This effect is enhanced (caps at 50%) for every 1 level difference (positive value) between your units' lowest level and the enemy units' lowest level. | +20% | Attack |
| Slug copter | Air Force Protection | 5 | Decreases damage taken for all your copters. This effect is enhanced (caps at 50%) for every 1 level difference (positive value) between your units' lowest level and the enemy units' lowest level. | +20% | Attack |
| Slug copter | Vehicle Protection | 5 | Decreases damage taken for all your vehicles. This effect is enhanced (caps at 50%) for every 1 level difference (positive value) between your units' lowest level and the enemy units' lowest level. | +20% | Attack |
| Slug copter | Active Protection | 5 | Temp. decreases damage taken for all your units. | +30% | Attack |
| Slug copter | Unit Firepower I | 5 | Unit Attack | +10% | Attack |
| Slug copter | Unit Firepower II | 5 | Unit Attack | +50% | Attack |
| Slug copter | Unit Defense I | 5 | Unit Defense | +20% | Attack |
| Slug copter | Unit Defense II | 5 | Unit Defense | +45% | Attack |
| Slug copter | Bounding Overwatch I | 5 | Unit HP | +20% | Attack |
| Slug copter | Bounding Overwatch II | 5 | Unit HP | +45% | Attack |
| Slug copter | Vehicle Firepower I | 5 | Vehicle Attack | +20% | Attack |
| Slug copter | Vehicle Firepower II | 5 | Vehicle Attack | +45% | Attack |
| Total Steps: | 90 | 38.3M Air Force Points |
When all Attributes are maxed:
| Buff | Modifier | Usage |
|---|---|---|
| Unit Attack | +125% | Attack |
| Unit Defense | +65% | Attack |
| Unit HP | +65% | Attack |
| Decreases damage taken for all your commandos. This effect is enhanced (caps at 50%) for every 1 level difference (positive value) between your units' lowest level and the enemy units' lowest level. | +20% | Attack |
| Decreases damage taken for all your copters. This effect is enhanced (caps at 50%) for every 1 level difference (positive value) between your units' lowest level and the enemy units' lowest level. | +20% | Attack |
| Decreases damage taken for all your vehicles. This effect is enhanced (caps at 50%) for every 1 level difference (positive value) between your units' lowest level and the enemy units' lowest level. | +20% | Attack |
| Temp. decreases damage taken for all your units. | +30% | Attack |
Plane Special Skills:
Plane Special Skills are buffs that can be activated manually and last for a limited time. They have a "cool-off" period (which is usually 24 hours, but might be less) such that they can only be used once until the cooldown period expires. Many of these are quite powerful, one-time buffs that can be activated for the next attack. These skills are only available when you have maxed out the specific Plane's Attribute. To activate the Special Skill, go to the Battlefield Screen and click the icon in the lower-left corner with an officer hat and a plane: 
Slug Copter has the Active Protection Special Skill which, when activated, temporarily decreases damage taken for all your units.
Slug Copter's Active Protection skill can be enhanced by improving your Chief of Strategists Command Department.
NOTE: You do not have to use the Plane that has the Special Skill in your march in order to reap the benefits of that skill, you only need to activate it. Put another way, you can activate the Special Skill for one plane and use a different plane and still get the benefit of that Special Skill. I have verified this.
EXP needed to upgrade level:
| Level | New Energy Cost |
|---|---|
| 1 | 1,000 |
| 2 | 1,100 |
| 3 | 1,210 |
| 4 | 1,335 |
| 5 | 1,470 |
| 6 | 1,620 |
| 7 | 1,785 |
| 8 | 1,965 |
| 9 | 2,165 |
| 10 | 2,275 |
| 11 | 3,185 |
| 12 | 4,460 |
| 13 | 6,245 |
| 14 | 8,745 |
| 15 | 12,245 |
| 16 | 17,145 |
| 17 | 24,000 |
| 18 | 33,600 |
| 19 | 47,040 |
| 20 | 49,410 |
| 21 | 51,885 |
| 22 | 54,475 |
| 23 | 57,195 |
| 24 | 60,055 |
| 25 | 63,060 |
| 26 | 66,210 |
| 27 | 69,520 |
| 28 | 73,000 |
| 29 | 76,650 |
| 30 | 80,480 |
| 31 | 84,505 |
| 32 | 88,730 |
| 33 | 93,165 |
| 34 | 97,825 |
| 35 | 102,715 |
| 36 | 107,850 |
| 37 | 113,245 |
| 38 | 118,905 |
| 39 | 124,850 |
| 40 | 131,095 |
| 41 | 137,650 |
| 42 | 144,530 |
| 43 | 151,760 |
| 44 | 159,345 |
| 45 | 167,315 |
| 46 | 175,680 |
| 47 | 184,465 |
| 48 | 193,685 |
| 49 | 203,370 |
| 50 | |
|
Total EXP to max: |
3,455,215 |
| New Energy: | 26,785 |
General Plane Promotion Material can be used to Promote Planes (increase their star level). Slug Copter requires the following General Plane Promotion Material:
- 1
- 2
- 3
- 4
Air Force Cultivation Card Cost:
Although many planes can be promoted by purchasing Air Force Cultivation Cards from the Premium Gift Card Event, Slug Copter is not one of them, at least as far as I have seen.
Plane Specific Pilots?
Slug Copter does not have specific pilots that give it bonuses.