Flight below minimum sector altitude involving Cessna 310R, VH-ZMB, 14 km west-north-west of Alice Springs Airport, Northern Territory, on 1 July 2024 AO-2024-039 01/07/2024 Final 20/03/2025. The Final Report just published
For some unknown reason I was unable to download the Final Report despite earlier having no trouble dowloading it successfully. Could be finger trouble on my part.
Basically it seems the pilot got badly disoriented while manoevering to get on to the ILS on a black night approach into Alice Springs. He had angles of bank varying from 60 degrees to 45 degrees while on the LLZ which he thought was failure of the captains AH and gyro compass. He was within 800 ft of high terrain at one stage. Eventually he landed safely.
The ATSB investigation revealed the AH did have slight errors beyond normal tolerances but was considered by ATSB as not affecting safety of flight and that it was pilot disorientation in IMC that was the primary cause of the incident. Certainly a frightening experience for the pilot. Then you have to ask how bad was the maintenance to allow an out of tolerance AH which no doubt would not have been written up in the maintenance by other pilots who flew that particular Cessna 310
The report showed a photo of this Cessna 310 flight instrument panel. The first thing that interested me was the position of the second AH which was on the co-pilot's side if one was carried. It was situated low down and to the far right and completely out of view from the left seat pilot unless he leaned right over to his right and looking down which would have really disoriented the most competent of pilots. I understand that two AH's are required to be installed for IFR twins. In this case the pilot of this aircraft having a suspicion that his AH is defective could have checked the second AH as a comparison. But it was practically impossible for him to do this because that second AH was well out of his scan
I have seen this type of installation of second AH's on numerous GA types making the aircraft hard to fly in IMC since that AH is often placed in an awkward spot on the instrument panel that makes it difficult to scan easily. Yet it apparently meets the IFR requirements. This situation was like that 30 years ago. If a second AH is the legal requirement then put it directly in front of the right seat pilot not impossibly tucked in the bottom corner of the instrument panel. CASA flight safety people - where are you when you are needed most?. I would have thought ATSB could have mentioned the impossibility of the pilot being able to use the second AH in its present position on the instrument panel and make appropriate flight safety recommendations.
It could be argued the pilot already had an electrically powered Turn Coordinator as a cross reference to his AH. But what an utterly useless flight instrument that is when the chips are down on a black IMC night unless you are current and highly proficient on limited panel flying - a very rare attribute nowadays.
In response to the CASA input to this incident, the company recommended its pilots use the autopilot in IMC to reduce pilot workload. While they are fine words, autopilot proficency is far removed from manual instrument flying proficiency. Ask any airline pilot if is he happy to fly a raw data ILS in IMC. No way!.