IFR certified

[GAHorn]

The reason I specified "anecdotally" was because I can't recall the source-document for the 30-degree view.

The background for much of my trivia is my experience as DOM for an American Express subsidiary back in the late '70's-early 80's. I had the responsibility of importing/exporting several of the corporate airplanes which required them to meet certification requirements which would be approved by a DAR. It was a huge waste of money if we called the inspector to the scene and he refused to sign off on the airplane due to some technicality. Many of the mods were "one-off", or "one-of-a-kind" and involved cockpit mods, and lots of those were instrumentation changes away from already approved layouts.

One airplane I specifically recall involved the installation of a 3rd gyro for emergency reference. The airplane had rec'd it's original airworthiness certificate prior to the rule change that made such gyro's mandatory, and ordinarily the airplane would have been grandfathered. But since it was being exported to one of our foreign flight departments it required an export C of A, and that req'd meeting the new rule. Unfortunately the existing panel had no available space to place that gyro, and the DAR presented the rule that led to the "primary" field of view discussion in placing that gyro. We ended up spending about $11K modifying a panel to install a $2K instrument.

That was back in 1983, and I'd venture it's unlikely that rule has changed. Perhaps one of our Boeing or airline members or one of our "lurkers" might posit a written reference if anyone still feels the need.

[hilltop170]

I'm glad to see you changed your shoes, Richard. Those little dainty feet are much better suited to black.

I wear my dark tennis shoes when I fly at night.

[trake]

My 170 doesnt have venturis or gyros. Definitley performs better than with them. Liking the lower maintenance too. I have to be more careful at night and in marginal weather. Im waiting for someone to make an affordable, portable electric atitude indicator. IMO 170's get doggy when loaded down with IFR gear.

[GAHorn]

A Garmin 196 is a fair safety item in such aircraft.

[GAHorn]

...I can't say if there every was an approach certified Loran but I'm sure there was an enroute certified Loran. ...

The KLN-88 was approach certified until FAA killed Loran approaches in favor of GPS. Now that Loran is being re-juvenated perhaps they'll restore Loran-based approaches. (My KLN-88 has the capability of navigating RNAV-GPS approaches. I've loaded such approaches into it and flown them in VFR conditions. While not as precise as GPS (15 meters), Loran is pretty good nonetheless (30 meters). Unfortunately Loran is victim of some atmospherics that degrade it's accuracy, especially mist or rain, which occasionally results in a warning when errors approach .1nm or greater. During such times approaches are dis-abled, similar to GPS-receiver behavior when a loss of RAIM occurs in GPS units. Loran accuracy (a timing matter) can also be influenced by local topography such as coastlines and large bodies of water. For that reason Loran units certified for approaches have local correction factors loaded into their databases. It is that local-correction-data that is no longer published/available which prevents Loran from being reliably used for approach. (From experience with the unit, in a "pinch" I'd have no qualms about using a KLN-88 in the terminal area or down to non-precision minimums as long as no error-msgs were being displayed, but not as "stand alone" during precip.)