Brittle Vacuum Hoses & Some Excitment

[Dave Underwood]

Some maintenance thought for you:

On a recent flight in solid IFR at night I noticed the vacuum had decreased slightly and the HSI no longer able to do its job. This was discovered when I turned through 180 degrees using the Heading bug during a hold as everything had been fine until then (at least I think it had been). Nor could the DG accurately track the vectors on the approach.

It was also one of those "ah shit" moments when you realise both the light in the compass and the light over the T&B are not working making things even more interesting when you try and do needle-ball-compass etc.

The AI was still erect and the HSI in the Gramin 530 was also a great help as I took no gyro turns to final and broke out at about 700 feet to see those beautiful landing lights.

The problem was a split in the vacuum hoses under the panel AFTER the check valve on the line to the HSI. Easy to fix, but when looking at the hoses generally they are getting brittle.

Glad Cessna put in separate vacuum lines to the AI and HSI.

The maintenance thoughts are: 1) check & replace brittle tubing and 2) make sure all the panel lights work.

Blue skies - Dave

[Pete Somers]

Nice one Dave!

Thats the problem with those EDO-AIRE HSI although they are Vac they also require power to run them.
So if you lose either VAC or Power you lose the HSI.

Pete