Date: 202104
Local time of day: 1201-1800
Location: OKC.TRACON, OK
Aircraft: Military Trainer
Operator: Military
Flight plan: IFR
Mission: Training
Flight phase: Climb
Airspace: Class C OKC
ATC / advisory: TRACON OKC
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Distraction; Situational Awareness
Anomaly: ATC Issue All Types; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Contributing factors: Procedure; Human Factors; Environment - Non Weather Related; Airspace Structure; Chart Or Publication
Primary problem: Human Factors

Narrative: I was working Approach Control when Aircraft X was vectored below the Minimum Vectoring Altitude. During the review of the session; there were several things that stood out to me that I felt were important for discussion. First; there was a lot of coordination going on with the surrounding sectors and facilities. The ensuing coordination was thorough and complete. Secondly; during the coordination with Wiley Post Tower Aircraft X checked in on his missed approach. He was instructed to fly heading 080 and maintain 4;000 feet on the missed approach procedure. The aircraft had previously read back the instructions correctly. However on departure he reported leaving 2;000 for 3;000 feet. As I was on the line with Tower I neglected to verify his altitude and expectation bias took over. I noticed that Aircraft X was inside the 3;800 foot Minimum Vectoring Altitude area level at 3;000 feet. I immediately took corrective action and instructed him to climb and maintain 4;000 feet and turned him left to exit the area. I did not use the complete safety alert phraseology. Aircraft safely exited the Minimum Vectoring Altitude area. I have a lot of different suggestions on how I could've done better. Firstly; I could've asked for help when the coordination became excessive. This was during a shift change and there were no fewer than eight people in the TRACON at the time. In fact one of my good coworkers was conducting training next to me and he and I usually keep an eye on each other's traffic. No one noticed out of the eight people present that this aircraft was approaching the Minimum Vectoring Area. I also believe that having so many people in the area including two trainees just behind me speaking about the operation; caused me to be slightly distracted. I remember placing my hand over my earpiece so that I could hear better. I believe that I had an expectation bias that the aircraft would be climbing out of 3;000 for 4;000 feet.I believe the aircraft may have had an expectation bias because previous to this approach at Will Rogers he had done numerous approaches at an adjacent airport. The missed approach off of the adjacent airport is heading 080 and maintain 3;000 feet. Even though the aircraft read back the correct missed approach instructions assigned I believe that it was possible that the aircrew maintained 3;000 feet in error rather than 4;000 feet as previously assigned due to the fact that they had done multiple missed approaches climbing to 3;000 feet. One suggestion for a procedure change would be for the Tower controller to not only assign the assigned heading on departure as they do now but also re-issue the altitude. I will make sure to review the proper phraseology for issuing a safety alert. I neglected to state the phrase Minimum Vectoring Altitude in your area is 3;800 feet.




Synopsis: A TRACON Controller reported a military aircraft conducting practice approaches did not comply with the Missed Approach assigned altitude and flew below the Minimum Vectoring Altitude.