ARTCC Controller and CIC reported aircraft cleared for approach descended below their assigned altitude resulting in flight towards terrain and ATC was unable to communicate with the aircraft.
Synopsis
ARTCC Controller and CIC reported aircraft cleared for approach descended below their assigned altitude resulting in flight towards terrain and ATC was unable to communicate with the aircraft.
Narrative
I walked in at XA:05 local; to see that were sector X/Y split off from sector Z. Im sure it was because of the numbers on the board; but every CPC knows that sectors A and B get a heavy ZZZ push around XA:15. I walked in; however; to see Sector Z on its own; with 5 aircraft in a 250 square mile airspace. OS (Operations Supervisor) was a previous CPC so he knows what to expect; traffic wise; for sectors A/B. He decided to split sector Z off instead. Then he gets Controller A to be a CIC and I hear him tell Controller A that he wants 6 cpcs and some D-sides to come to a crew breakout. This would have left us with 4 CPCs & 1 D-side working; with 1 CPC on break. And he said he would be back at XB:20. A whole hour for a crew breakout?I was working sectors A/C/B for about an hour. During that hour I was busy with vectoring or speed managing multiple aircraft for metering times; giving approach clearances at multiple airports; icing reports (and filling out PIREPs); some turbulence reports; and a high amount of aircraft; all on 3 different frequencies. I actually asked Controller A to help me as a quasi D-side; which helped me greatly.After an hour it settled down; for a few minutes and right before a lot of aircraft were going to enter my airspace I had cleared Aircraft X to 'cross ZZZZZ at or above 100; cleared straight-in runway XX approach; ZZZ1.' The read back sounded good; but I was pretty tired after the busy hour; so I can't remember now if it was. 10 miles before ZZZZZ; the IAF; Aircraft X descends below 100 and down to 073 at the lowest. I immediately try to reach him on my frequency; on 121.5 and even had Controller A try a different 121.5 transmitter; which all led to no response. Soon after; I had to give a briefing.If OS didn't take so many CPCs for his crew breakout; we would have had enough CPCs to work as a D-side; or even split sector B off when it was appropriate.Recommendation: OS is known to try and 'stand out' from his other OS's; so he tries incessantly to check every box he can look good to his bosses. I don't know if it's due to pride or if he is chasing a raise. But to me it's clear that he should be told that safety in the control room comes before pride or money.
Second reporter narrative
I was left with the CIC desk in an unusual configuration for the time due to the request of the supervisor who left instructions with the preceding CIC to let me know that on the hour when the next set of controllers who arrive to go to a crew breakout. Leaving me with a situation where a sector needed to be split but would not be due to the crew break out. Sectors X/Y/Z would together is the midnight configuration; this was well into the shift. The sector had a ZZZ departure push; ZZZ1 departures through flight service; two ZZZ2 arrivals requesting IFR approaches. Sector Y was the busy with overflights. Sector Z had a large number of ZZZ3 arrivals who we were metering for; as well as the aircraft in the report here who was the second of two ZZZ4 arrivals in the sector who wanted IFR approaches. There was moderate clear ice on the arrival into ZZZ4.As the CIC I was unable to perform my duty as the CIC as I sat as a quazi D side on the sector putting in PIREPs; pulling up NOTAMs; and getting in routing. We had 5 in and 2 out at the time. The Sup took 5 R sides and a D side or two to a crew breakout that was way to excessive. He wanted a 6th; but I could not even get him off position to go to the breakout. The incident itself was Aircraft X who was after vectors to the east to create space for the subsequent arrival was cleared in correctly to cross ZZZZZ at or above 100 cleared ILS XX ZZZ4. I wasn't there to hear the readback but he was shipped to advisories and at that time he dropped to 073 which is 2700' below the MIA (Minimum IFR Altitude) and below the cleared altitude 10 miles outside of the approach fix ZZZZZ. The controller who was over an hour into dense traffic did call in the blind multiple times trying to execute a low altitude alert. As CIC I tried to call on guard and do a low altitude alert as well as have him come back on frequency. Neither of those were successful. I believe that an unsafe situation was created by an attempt to check a box and get as many controllers as possible to a crew breakout so that this supervisor specifically could show that he is the one that gets things done in the area; and that the other sups are not. Recommendation: I'd recommend we not forget that safety comes first and in an understaffed facility we should be waived of the extraneous activities such as CBI (Computer Based Instruction); crew breakout; the government email; ETC.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.