Beechjet 400
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Rejected Takeoff; Flight Crew Overcame Equipment Problem
Aircraft; Human Factors; Procedure
Just before takeoff the HDG and NAV buttons were armed.  During takeoff; just after power was set and the aircraft began to roll; I noticed that the the green heading and pitch symbols on the Primary Flight Display had a red line through them.  I called for the abort and the SIC notified Tower.  I executed a low speed abort using minimal breaking after determining that the sufficient breaking was available to slow.  With an aircraft on the approach behind us we were told to exit on Runway 1 with some expediency.  We missed Runway 1 then were told to exit [on Taxiway] R which we accomplished.  While holding  short on Taxiway Q we initiated a checklist.  I noticed that there was an accompanying yellow ATT 2 flag on the Primary Flight Display.  The checklist indicated that the cross side attitude was displayed.  Under action required it indicated that the autopilot would not be able to be engaged in this state.  I then noticed that the AHRS 1/2 button was in the 2 position.  I switched the tiny button back to 1 and the problem was solved.  It is not known how the button came to be depressed though the aircraft did just get cleaned and have some maintenance done; though it could have just as easily been pilot error.  This was caused by an insufficient pre-takeoff instrument scan.  Fully incorporating the smaller buttons such as the AHRS 1/2 into the  preflight instrument scan as well as the pre-takeoff instrument scan. Always setting the navigation mode to be used during the before taxi check so as to provide more time to confirm; verify; and incorporate the associated Primary Flight Display annunciators into the scan.  This is not always feasible as plans can change during the taxi.
I was Pilot Not Flying for a departure from Runway 6; in TEB.  During the takeoff roll; soon after the power was set and I made the 'power set' callout; the Pilot Flying made the 'abort' call and I notified the Tower that we were aborting the takeoff.  We executed a low speed abort maneuver using minimum braking.  We were instructed by Tower to exit the runway and we exited on [Taxiway] R.  After exiting the runway; I questioned the Pilot Flying and he informed me that he had red lines through heading and pitch readouts on his Primary Flight Display.  While holding short of Taxiway Q; we informed the Tower that we would need a couple minutes to evaluate the problem.  We initiated the checklist and noticed the an ATT 2 flag on the Pilot Flying's Primary Flight Display.  The checklist stated that the cross side attitude was being displayed.  The checklist stated that the autopilot would not be able to engage in this state.  The Pilot Flying then noticed the the AHRS 1/2 button was in the 2 position.  He then switched the button back to indicate the Primary Flight Display was displaying the number 1 attitude; and then the red lines disappeared.  We are not sure how or when the button became depressed.  The aircraft had just been cleaned and had some maintenance done on it; though that is just speculation; as it could have been an error on the pilot side as well.  With the error fixed; we informed Tower we were ready for takeoff again; they instructed us to proceed back the the departure end of Runway 6; where we proceeded to takeoff and continued the flight without incident.  Once in cruise; and at a portion of the flight where is was safe to do so; we discussed the incident.  We came to the conclusion that we need to be more aware of these smaller buttons in our cockpit setup; and our pre-taxi and taxi instrument scan.  These buttons are not included in the checklist but serve vital a part in the safe operation of the flight.  There are times where speed to complete a task can lead one to bypass these buttons in the scan and/or cockpit setup.  We need not forget this incident; and in the future; make sure to include this section of the cockpit in the setup and scan to ensure this does not happen again.
BE400 flight crew reports rejecting a takeoff at low speed due to the Captain having red lines through heading and pitch readouts on his PFD.  The AHRS 1/2 button was in the 2 position and switching back to the 1 position solved the problem.