Instrument Failure

Guest Discussion
41

In reply to:

Mike, my experience with the Century electric HSI conflicts with Cirrus’ perspective. I’ve had the following problems:

  1. Glidslope stuck in the one line down position
  2. Glideslope working okay, but flag down
  3. Heading bug off by 10 degrees
  4. Heading bug and yellow arrow collided, bending arrow
  5. Bad interface with autopilot
  6. Replacement unit bad; never installed
  7. 7’s a charm; 7 months problem free!

While I suppose it could be the plane, and I respect Cirrus’s diligence on this, it seems like bad QC by Century.

Andy,
Sure does sound like bad stuff from Century. Hopefully, Cirrus knows about your plane as one of the dozen or so with HSI problems, and someone recognizes that your particular bugs don’t seem airplane related.
The August, 2001 Aviation Consumer ran an article titled “HSI Flyoff”, in which they compared HSIs from Bendix/King, Century (NSD 360A and NSD 1000), STEC and Sandel (the SN3308). Overall, the Century NSD 360A - the vacuum model - compared well. They liked the NSD1000, but on reliability, said the following:
"This (the self-contained gyro) is one reason why Cirrus picked the NSD1000 for its SR-20. Cirrus and owners, however, tell us that this choice hasn’t yielded the perfect panel. Numerous failures have been reported – one owner had four failures.
"This is consistent with owner reports we’ve received. A few NSD1000 owners we know report a fair amount of maintenance associated with this instrument.
“A Baron owner with a low serial NSD1000 told us that his HSI was back at the factory three times with less than 1000 hours of service. The gyro was overhauled, meter assemblies replaced and repairs made to a sticky glideslope flag. The factory provided loaners when appropriate but clearly this incidence of repair is an inconvenience any owner would like to avoid.”
The caption below a photo of the NSD1000 reads, “Although it eliminates the vacuum requirement, it’s not a top choice due to maintenance issues.”
All of this seems to confirm the view that the Century NSD1000 really is less reliable than it should be; so perhaps it is surprising that Cirrus is looking for possible airplane issues. It’s not at all surprising that they are offering the Sandel as an alternative…
… and while we’re on the subject of the Sandel… the same Aviation Consumer had this to say about the SN3308 (implied: In anything less than a Malibu or Saratoga):

“Sandel pro: Lots of room to upgrade. Sandel con: Like wearing a tux to a tractor pull”] [:D]

Mike.

42

My avionics guy, who I think is excellent, says that there are lots of problems with the Century HSI’s, but when you get one that works, it usually continues working well. My experience is consistent with this.

Cirrus is aware of my experience.

One thing I’ll say about the Century units - they’re easy to swap!

Andy

43

Derek, what did it cost you to upgrade?

Andy

44

I actually delayed delivery of my SR20 ten months (or ~80 positions) so that I could get the Sandel. Got the GW increase/G327 transponder/Avidyne/new cowl & light as a “bonus.” Of course, at the time I thought it was only a 3 month delay…

The only glitch so far has been some inadequate Avidyne installation instructions which broke the link between GPS1 and the Sandel. If your Sandel can no longer read the GPS signal after installing the Avidyne, you probably need to reset the G430 data transfer speed to a lower setting. According to my service center, this was not documented in the installation guide, but is actually user-adjustable.

45

It was offered with the airplane at the factory. I believe it was $5,000 (assuming you had dual alternators and a B or C model).

46

Michael, what is the name of the service center that detected the comm link problem?

Thanks, Stuart