pilot report.
HRS 9950.3
CYC 5311
Yellow HDG miscompare at rotate, and sometimes descent. Both HDG seem identical, even when HDG CMPRTR warn is present. Verfied. Rplced #1 ahrs.
#2 AHRS CB pops. Previous troubleshooting found a grounded , burned in two, power wire near fwd RH card cage in the nose. Possibly verified. Slave control free switch contact burned. Smoke evedence. (Picture). Repaired wire.
Repaired wire at #2 AHRS slaving control panel switch. #2 AHRS system ops test good I.A.W AMM 34-21-00710


Pilot and copilot tx sidetone very loud, cabin sidetone, ics sidetone normal. Verfied.
Adjusted pilot Audio control box P/N M1045-fbaa-hj7f S/N 9010358, and copilot s/n , headphone level, speaker sidetone level, ICS level, and ICS sidetone level I.A.W. AMM 23-50-01-820-801. Crew ICS system ops checks normal.


Ectm 1, needs download
Number 2 RMI flag flickers into view. Troubleshot by AHRS swap and STIM. Failure is now pilot RMI. order AHRS collins AHC85E, P/N 622-6190-204 , failed S/N 726( causes RMI flag to flicker into view.
AHRS swap detail: Units are now swapped to:

#1 unit, Aft. P/N.622-6190-204 S/N 957
#2 unit, Fwd. P/N.622-6190-204 S/N 726 (causes RMI flag to come in view)
Removed failed AHRS computer #1. Installed overhauled unit. Unit recieved on Duncan W/O 4K0Y6, from Regional Avionics Repair WO. 2020-9726.
Parts off: P/N. 622- 6190-204. S/N 726. (Causes HDG flag to flicker)
Parts on: P/N. 622- 6190-204. S/N 866.
Unit installed I.A.W. AMM 34-22-01-900-801. AHRS system #1 ops checks normal.
P.brake bleed down. Needs troubleshooting.
TERRAIN DISPLAY button inop.
Lh main brace leak, needs troubleshooting.
2 hyd pump bad,2000 psi replace pump. done.
Busstied ann and other anns , needs bulb.
Crew temp valve resistor dead, passenger has rough spots near full cold. Needs crew dual temp valve.
Wednesday early am. L ahrs displayfail with original in aft postion, and rh rmi flag in view. R rmi card shakes. Center MFD shows red DRV. This ended up being….AHRS will not STIM with STBY battery breakers in.
MFD Red DRV is a problem. Rerack MFD solved this.
No ALIGN light on MSU. Replaced with serviceable.
Parts Off.
MSU p/n CG1042AB03. S/N 1084 (align light inop)
Parts on:
MSU p/n CG1042AB03. S/N 461 (removed from inservice aircraft, see Pollard Spares LLC SO5857. Init ops test good refrence AMM 34-21-00-710-801



Ann bulbs
#2 hyd qty
Panels at pylon
Window seal
Cabin floor.
Low fuel light
Number 1 dme ind dead.
Left closet avionics fan loud
Terrain display inop.
Why is number 2 dpu 622-9009-001, #1 is -002
?——————————–
Week starking June 9
New items:
Left pylon leak
Aft compartment leak
Skin temp thetmostat at rh wheelwell not bonded.
Air check valve left side f4 tape
dv window has jumped the rack and pinion, needs reseal.
#1 and 2 mlg tire condition.
Fuel sample bottle clip brocken.
BATT 1 amps blue lamp inop.
Pilot and copilot window shades need rewind, small glue repair.
Low fuel light on
Hyd qty low
Number 2 transfer light will not go out.
Red CABIN light rigged on the edge,
MED overserviced, upper fwd seal area gap., fwd side mid to fwd upper corner. Check rigging also.
Dv window jumped off teeth, check stripped bolt.
No terrain display.
Ectm 1
Pilot reports 30 degree heading split.
98dh left alpha, then 13
Copilot seat no springback in seat lock. Also rocks for/aft
IRU will sometime start with FAN FAIL.
July 20, 2020

May 2022 visit.
Discrepancy:
IRU Failed. Left
Left compass squirrely, RH RMI flag dance, Pilot wind vector crazy.
Verified TCAS operates when IRU OFF
Verified EGPWS failed when IRU OFF
F50_Heading Channel Left side
F50_Heading Channel Left side
F50_Heading Channel Left side
Page two is the VALID conditions for the AHRS.
We have no HORIZON flag, so that leaves only a few things that will cause SERIAL HDG flag (EFIS HDG FLIG IN VIEW)…..and……. PIN 9 LOW. (ANALOG HDG FLAG IN VIEW, RMI.)
The things that are possible are upper left.
COMPENSATION is the one I suspect.
I think we can rule out SLAVING, because we have a flag in SLAVED and in FREE.
We need to swap the compensation modules next.
Todd
