Corporate flight crew reported erratic GPS information; possible jamming; during a climb on a published instrument departure procedure which resulted in a course deviation.
Synopsis
Corporate flight crew reported erratic GPS information; possible jamming; during a climb on a published instrument departure procedure which resulted in a course deviation.
Narrative
We departed runway 25L at Phoenix Sky Harbor airport. We were assigned the FORPE 1 SID. After going airborne; we were flying the assigned departure when our GPS began displaying erratic information. While attempting to diagnose the problem we were observing; the navigation turned us to a right hand turn and also at that time; the flight director disappeared. As I realized I needed to make a turn back to the left; the controller directed us to a left hand turn to a heading of 270 which we complied with immediately. At no time did we receive a RA or observed any aircraft in close proximity to our aircraft. We advised the controller of the issue we were having at that time. Shortly after that issue; we overheard an airliner advise the controller that their GPS was being jammed. I was at that time that we began to realize that a jammed GPS could very well have been our issue as well as that could very well explain our erratic GPS display. What we could have done to help prevent this was to not rely on the GPS as much and be more aware of the text departure so that in the future if this may happens; we know the heading required without becoming complacent on the aircrafts navigation system.
Second reporter narrative
We departed 25L at Phoenix. We were cleared via the Forpe 1 RNAV departure. Both FMS's were verified for the correct departure fixes for that runway. Shortly after departure our navigational displays were giving us information that we soon determined to be false. We began to correct our heading and stated the problem to departure control. Within the next couple of minutes of being vectored we heard an airliner say that he was indicating GPS jamming.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.