Fractional jet flight crew reported receiving a low altitude alert from ATC on their approach to 4I3 airport; citing communication difficulties as contributing.
Synopsis
Fractional jet flight crew reported receiving a low altitude alert from ATC on their approach to 4I3 airport; citing communication difficulties as contributing.
Narrative
IMC conditions enroute. Planned for the RNAV 28. CMH Approach Controller appeared extremely busy. We were flown through the final approach course and were having communication issues most likely due to the precipitation that we were flying in. The Controller attempted to vector us back for the intercept; but the heading was not adequate to intercept the course. We thought that we heard '2;000 until established; cleared for the approach' which we read back with no response. We both verified the altitude and dialed it in while still attempting to intercept the course. We advised the Controller that we needed a better heading; again with no response. At that time; the Controller initiated a low altitude alert for us. We were approximately 2300'. We acknowledged the alert and climbed back to 2700' which was the charted minimum for the FAF. We were established on the final approach course at that time. Throughout the incident; the Controller said many times that she was not hearing our responses and her communications were fairly garbled as well. After attempting to contact her on Guard frequency; we resorted to flashing the IDENT button in response to her calls. We continued the approach from the FAF at the prescribed altitude with no further issues. The main factor here was the obvious communication interference. Also contributing was the Controller workload and our workload as we got flown through the final approach course. While trying to get re-established; we apparently misheard the altitude assignment through the static and descended past the FAF altitude.Suggestions: From a crew standpoint; we were both positive that we heard '2;000' and verified that it was set properly per company SOPs. However; in the attempt to communicate our need for a better heading for the intercept; we did not realize that 2;000' put us below the minimum altitude of 2700' at the FAF. This is something that we should have queried the Controller about.
Second reporter narrative
We were preparing to perform the RNAV 28 into 4I3. The crew was flown through the final approach course initially and were at 3;000 feet. The next transmission from the Controller came in very broken. Both pilots heard turn left heading 290 and maintain 2;000 until established on the approach. I read the clearance back with no correction from the Controller. Both pilots realized that the heading that we were given would not intercept the final. We began our descent to 2;000 and at approximately 2;300 we realized we were below the minimum altitude for that segment of the approach which was 2;700. At the same time; we could hear the Controller issue a low altitude alert for us. We immediately began to climb to the minimum altitude. For the rest of the flight; we could hear the Controller but she could not hear us. We arrived safely on the ground after completing the RNAV 28.Suggestions: Recommend [notifying] crew members that they may lose communication with ATC at low altitude.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.