Print
Hits: 2498

I got another flight off this morning, this time with a passenger, so I could do some mid-aft CG autopilot testing:

Flt 99 Notes, 03 Jan 2011

Purpose:
#2 Cylinder Break-In
Trio Autopilot checkout at mid aft CG

Ran engine at about 75% power with mixture set for 100 deg ROP at 2500 to 4000 ft.

Had about 191 lb of self-loading ballast (thanks Ian!), and 36.6 USG fuel, for 1800 lb/84.47" wt/CG at start.

I had been concerned that the large difference in longitudinal stick forces between forward CG (solo) and aft CG (with passenger) would mean that no single set of autopilot pitch gains would work for both cases. The results from this flight suggests that it is very likely that this is not a problem.

GNS 430W RS-232 settings:

+--------+-----------+----------+----------------------------------------+|        |   In      |   Out    | Notes                                  ||--------+-----------+----------+----------------------------------------+| Chnl 1:| Icarus Alt|   OFF    | From GTX 327 Xponder                   || Chnl 2:|   OFF     |   OFF    |                                        || Chnl 3:|   OFF     | Aviation | To Trio Autopilot and data recording   || Chnl 4:|   OFF     |   OFF    |                                        |+--------+-----------+----------+----------------------------------------+

GNS 430W ARINC 429 settings:

+-------+------------+| IN 1: | OFF        || IN 2: | OFF        || OUT:  | ARINC 429  |+-------+------------+

Trio Autopilot Config Settings:

VNAV Servo Direction: ReverseHNAV Servo Direction: NormalMax Turn Rate:        AutoVNAV Servo DB:        4

Trio Autopilot Preferences:

TRK Gain:      3CRS Gain:      4PI Gain:       9ALT HLD Gain: 60VS Gain:      50H Servo Gain: 35

Trio Autopilot MSN 316VF
Trio Autopilot SW 100612

The following autopilot gain checks were conducted in relatively smooth air:

ALT HLD - 75% power cruise, wings level, and turns of 15 and 25 degrees of bank. The altitude hold performance was very good at all times.

VS - climbs and descents at 500 and 1000 ft/mn were performed. The selected vertical rate was changed during the climb or descent. The autopilot promptly and smoothly captured the target rate with very little overshoot.

ALT SEL - the selected altitude was smoothly captured with minimal overshoot.

CRS - wings level cruise was excellent. Turns only used about 15 deg of bank angle, and the turn rate was further reduced during the last 30 degrees before rolling out. Turn performance should be further assessed with various settings of the "Max Turn Rate" config value.

TRK - track performance was excellent.

GPSS - excellent turns to intercept a flight plan track.