Even though they're supposed to be 'anonymous' here's what my first NASA report consisted of:
On Saturday May 10th at 1330 local time, I was involved in what could have been a runway incursion, between a Piper Arrow and a landing Regional Jet. The additional aircraft described as 'holding short number 2' was a Beechcraft Bonanza also on an IFR flight plan.
We were holding short of runway 27 full length, when the aircraft behind us called ready for departure. He was number 2, yet did not state his sequence. My student called ready for departure but also did not state his sequence. Tower advised both aircraft to continue holding short of the runway. A few departures and arrivals later tower responded. Clearing the number 2 aircraft for departure. He stated "there is an aircraft in front of me." Tower called back and cancelled his take off clearance.
Somewhere between clearing the number two aircraft and clearing my aircraft, an approaching regional jet was cleared to land on runway 27.
A few moments later tower called our aircraft and cleared us for departure. My student acknowledged with 'Cleared for take off, runway 27, fly runway heading.' Momentarily after crossing the hold short line tower called us back and advised us that our take off clearance was cancelled and that we were to hold short of 27. I responded this time with 'unable, we've already crossed onto the runway.' We were well beyond the line and well onto the runway threshold.
To that she responded to hold position. This was something that I was not comfortable with as I was now realizing the situation. She has a regional jet approaching with a landing clearance, and just now recognized that there would not be enough room for our departure.
I called her back advising her that I could still possibly clear the runway if needed. Tower advised to try and clear the runway if I could. That is exactly what I did, thankfully the number 2 aircraft was able to maneuver enough out of the way for my aircraft to squeeze by.
This put us back as number two for take off.
The regional jet landed, and she now called us back. 'Cleared for take off fly runway heading.' To this again I responded 'Unable, we're number 2.' To me this confirms the complete lack of SA as she wasn't even aware or even noticed our new sequence.
Cancelled my take off clearance again, and subsequently cleared the other aircraft for take off. After his departure we were then once again cleared for departure. The rest of our trip was uneventful.
The controller on duty at this time was working ground, clearance, and tower all by herself. It is my opinion that being overloaded with work caused her to lose situational awareness, and hampered her decision making ability. I felt that I was put in a runway incursion environment without even knowing it. The continued lack of awareness was evident after clearing the wrong aircraft for take off not once, but twice. To me it appeared that she wasn't even looking or was unable to see which aircraft was where.
In hindsight I could have done some things to help the situation. Correctly advising tower of our sequence while holding short. Paying more attention to the traffic on the radio. Unfortunately I was busy talking with my students during the regional jets landing clearance. However, I do remember it, but it didn't really register at the time that it would somehow affect me.
Looking back I can clearly see an error chain which involved myself, the other aircraft holding short, and the tower. Thankfully it was uneventful but it could have been much worse.