Date: 201702
Local time of day: 1201-1800
Location: ZDV.ARTCC, CO
Flight conditions: IMC
Light: Daylight
Aircraft: Small Transport
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class E ZDV
ATC / advisory: Center ZDV
Second aircraft: Commercial Fixed Wing
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Communication Breakdown; Confusion
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic
Contributing factors: Human Factors; Airspace Structure; Procedure
Primary problem: Procedure

Narrative: Weather was at minimums at EGE and occasionally dropping below that. We were holding arrivals; averaging around 5 at RLG VOR at any one time. On a report from an aircraft about 15 mins prior; the LDA approach; along with the FMS and ILS were at mins; and aircraft could probably make it into the airport. The first two or three aircraft to try the LDA after that were successful. Upon check on; Aircraft Y; was told to get the ATIS; and the situation with weather at EGE. I relayed to him that most of the approaches were viable. When clearing at RLG to start the approach; I issued the LOC FMS 25; due to the fact that that is what the LOA says with us and EGE TWR; and that most if not all [Aircraft Y's type] do that approach. Aircraft Y relayed they were unable to do that approach however; and requested the LDA. Knowing that was now also a viable approach; I cleared them for approach at RLG (as a side note; the LOC/FMS 25 was NOTAMED NA up until recently; and there was known confusion among certain air carriers whether they could still conduct that approach). After shipping Aircraft Y to Tower; we were asked a few mins later for a release on Aircraft X; to which we released via the LOA. When an aircraft is released from us to EGE; we are releasing with the understanding that any aircraft on approach; and shipped to them; Tower has the responsibility for separation; especially on a day where weather was at minimums; and occasionally dropping.Just as Aircraft X was released; EGE calls us and tells us that Aircraft Y is on the missed approach. At this point; there is literally nothing I can do but call traffic in IFR conditions; and give a maximum rate of climb. Separation was down to 2.47 and 700ft until vertical was achieved sometime later. In my opinion; this is entirely on EGE Tower. They should be aware of the situation evolving around the airport; and have the knowledge that other aircraft were going missed on the LDA and taken that into consideration before launching an aircraft; with poor performance characteristics no less.This particular situation has happened before; and there are multiple steps that; in my opinion need to be taken in order to make this operation safer. The COTTONWOOD2 Departure procedure and LOC/FMS RWY 25 should be discontinued as a viable departure and approach procedure respectively. There have been numerous incidents of either aircraft flying the engine out procedure initially on departure; or on the missed approach; and getting dangerously close to arrivals being sequenced into ASE south of EGE. Also; the fact that these continually are being NOTAMed out; then authorized; then NOTAMed out again because of this brings a level of risk to the system; where the airlines may be out of the loop and not be aware of the condition of these procedures on any given day. This it seems led to Aircraft Y saying they were unable to do the expected LOC FMS 25 approach; and instead doing the LDA.If there is any singular threat that aircraft may go missed approach while arriving at EGE; then departures should be suspended until conditions at the airport improve to above minimums. This will alleviate a lot of the guess work and bring an added level of safety without moving heaven and earth to do it.




Synopsis: ZDV Center Controller reported a loss of separation when an aircraft went missed approach at EGE as another aircraft was inbound.