Flight Crew Commercial; Flight Crew Instrument
Flight Crew Last 90 Days 19.9; Flight Crew Total 575; Flight Crew Type 300
Situational Awareness; Distraction; Human-Machine Interface; Workload
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Aircraft; Weather; Human Factors
During a flight to ZZZ my vacuum system failed with no warning. Originally I filed IFR to ZZZ1 due to weather conditions at my destination of ZZZ. My plan was to stop at ZZZ1 and wait for weather to improve before heading to ZZZ. This occurred roughly halfway through the flight. The conditions during the failure were solid IFR in the clouds at 8000 ft. I quickly noticed the attitude indicator seemed to be differing from the other instruments in a subtle way. I glanced at the suction gauge and saw it was zero. I already had the Century autopilot engaged for heading only (no attitude hold available) linked to multiple waypoints. I immediately reported the equipment failure to ATC. Soon after I requested a descent to an altitude to provide some view of terrain. I think was initially 6000; then 4000 later. Even at 4000 I ended up in solid IFR conditions later in the flight. As my initial destination of ZZZ1 was approaching; I saw that moderate rain (shown on Foreflight through Stratus) was near ZZZ1 and conditions there were deteriorating. I also saw that conditions at ZZZ were improving and were moderately VFR. Because I am so familiar with ZZZ and weather was deteriorating at ZZZ1; I requested an amendment of my final destination to ZZZ. Also; I couldn't find any larger airports with approaches and not in bad weather along my route of flight. The vacuum system failure resulted in the loss of my attitude indicator and DG (directional gyro). My main source of navigation and control was my Garmin 430 coupled with an older model Century autopilot in addition to the altimeter; vertical airspeed indicator and turn coordinator. I found the compass of nearly no use because it was extremely difficult to look up to the compass while maintaining a scan on the primary instruments. Additionally; I had a dash mounted iPad with Foreflight couple with Stratus II unit- I enabled the attitude and heading capability but didn't use it too much - it was great to have as a backup in case something else went wrong.I had just completed multiple ATC assisted navigation around moderate rain cells (Stratus worked well too; but has delays). These cells were not dangerous; but added to the challenge of maintaining full and steady control. At that point I reestablished a direct heading using the autopilot. For reasons I still don't understand; the autopilot put me in a turn. This autopilot only works if the current heading is close to the intended heading. I don't know if my heading was off when I engaged the autopilot; or if I unintentionally pulled the autopilot knob out which has the autopilot automatically do a turn at a selected bank. So; what happened was I ended up in a bank and noticed I started a 180 degree turn. I immediately reported this to the controller; disengage the autopilot and continued the bank until I was back on course. I maintained altitude the whole time; but obviously this was unnerving as I was in solid IFR. I re engaged the autopilot moments later and the same thing started happening again so I disengaged the slave of the autopilot; reestablished course and only used the autopilot to manually back and maintain level wings. The rest of the flight completed without issue. ATC (multiple facilities) were great at helping me through this. My main concern was that I lost directional control when I did the 360. Looking at the tracks I don't think my course was off by more than 1 nm. Afterwards I called ATC and asked if there were any issues I should be concerned with and they said no.In summary:-Flying with an attitude indicator and directional gyro is extremely challenging. I am very proud of how well I maintained control of the flight and the many decisions I made. -ATC controllers were very professional and did all the right things to get me home safely.-The autopilot issues are a real mystery to me. I know the autopilot well and use it a lot. I will need to check it out soon to make sure it is working right.-The Foreflight software with weather and ARHS is an unbelievable backup resource. Interestingly; however; twice the app quit and I had to restart it. This never happens. So I wouldn't want this to be my sole source of maintaining control.
Grumman AA5 pilot reported the vacuum pump failed while IMC so the pilot's iPad; Garmin 430; and Stratus II provided IMC navigation capabilities. The autopilot functionality decreased greatly.