Date: 201510
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: None; 25
Light: Daylight
Aircraft: Falcon 2000
Operator: Corporate
Operating under: Part 91
Flight plan: None
Mission: Test Flight / Demonstration
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Transponder
Component problem: Improperly Operated
Reporter organization: Corporate
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Workload; Situational Awareness; Distraction; Communication Breakdown
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Conflict NMAC; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: The maintenance crew chief asked the other pilot and me if we could perform a short maintenance test flight in the Falcon 2000 to check the engine anti-ice system. The purpose of the test flight was to determine if a problem had moved to the other engine after maintenance had swapped valves from side to side. This could only be checked in flight at high power settings as this was where the problem appeared.  We planned to fly a brief flight up to XXX VOR and back so we could get to a high enough altitude to have an outside air temperature cold enough to turn on the engine anti-ice system. We did not file an IFR flight plan as the weather was clear with unlimited visibility. We did plan to contact Approach control for VFR Traffic Advisories. We were also planning to troubleshoot a continuing nose-wheel steering problem that had been going on for almost a year.After engine start-up another Maintenance Technician was outside the aircraft to tap on the nose-steering unit with a rubber mallet if the control seemed to be sticking on initial taxi out. We made several short turns but could not duplicate the problem so we proceeded to the runway for departure. After several 90 degree turns we noticed that the plane wanted to constantly track to the right and slight steering inputs to the left would not correct the problem. It was only after larger inputs that the plane would jerk back to the left; the same problem that was seen on the last series of flights.Once we got to the approach end we performed the balance of the pre-departure checks and discussed that we would contact Approach Control once airborne. Once airborne the Pilot Not Flying (PNF) contacted Approach requesting traffic advisories while on a maintenance test flight. While on climb-out NFP asked if he should turn on the engine anti-ice system to perform the test. I told him 'not yet' and he thought I said 'yes' so he turned on the one engine. I then told NFP to turn it off because the TAT (total air temperature) was still 15 C; 5 degrees above the upper limit. The NFP then turned off the anti-ice and I then noticed that the control yoke was moving forward to a nose down position while I was hand flying the aircraft. At this point I thought that the autopilot had somehow gotten engaged and was leveling off the aircraft. I made the comment of 'what is happening'; when NFP stated that there was traffic crossing in front of us and that he was making corrections to resolve the conflict. As I looked up I saw what appeared to be a single engine Bonanza that came into view in my left windshield crossing left to right about 200 feet above us. I was surprised to see the aircraft and that we had no TCAS warning nor did I see any traffic on my MFD. I looked at the Transponder display to see if the code was in the display and then I looked at the Transponder switch to see that I was in the OFF position. I immediately switched the Transponder ON about the same time we heard Approach talking to the other aircraft explaining why he hadn't reported traffic (us) to him as he hadn't established radar contact with us because our transponder had was not turned on. The other aircraft reported that we crossed within 200 feet of each other. We continued climb to 10;500 feet; performed our engine anti-ice test; confirmed the failed anti-ice valve and returned to land without further incident. On decent we got a traffic advisory and also got a TA from the TCAS confirming that the system was working correctly.On post flight discussion with the other pilot I noted that this was the second time in the last month of flying with him that he has forgotten to switch on the TCAS system on leaving the blocks. Our checklist had been changed recently to put the TCAS switch as the second item on the checklist after turning on the taxi light instead of the first item to help another pilot who was also having difficulty getting the TCAS switched on. I feel that there were too many distractions during this flight that led up to the crew not being more vigilant about looking for other traffic. When we have ATC and TCAS systems working for us to help keep us clear of traffic we become complacent into thinking that these systems will prevent traffic conflicts. Also we should have briefed that we would not perform any tests until we were above 10;000 feet and clear of most other traffic. Trying to perform the anti-ice test so early in the climb was a major distraction which pulled me from looking outside into the cockpit. When the PNF smoothly but forcefully pushed the control wheel forward without saying anything as he was performing the maneuver; could have cause the PF to attempt to counter the control movement without realizing that it was the other pilot; not a system malfunction; and could have cause a disaster.We have a company Safety Management System in place and have identified this incident as a Hazard to safety and are in the process of conducting a full internal investigation and review with recommendations for changes and improvements to mitigate this from happening in the future.


Second narrative: During the early afternoon our aircraft needed a maintenance flight done to check a sticky engine nacelle heat valve and a problem with the steering. The day was clear VFR; unlimited visibility with the wind 090/06. I began the preflight with maintenance and as we circled the aircraft we discussed the problem the aircraft had had with the heat valve; how often it had stuck and that it had been swapped from one engine to the other in order to see if the problem followed the valve. I also asked if the valve was inoperative if there would be time to get it replaced for the upcoming flight that weekend. Maintenance assured me there was. I finished the preflight of the aircraft and the aircraft was pushed out of the hangar. The flying pilot; two mechanics and I discussed the steering problem and decided that if the system seemed to be sticking at all one of the mechanics would tap part of the system on the nose wheel with a rubber mallet in an effort to ascertain exactly where the problem was. I took the right seat and we proceeded to go through the various checklists. While we did this one mechanic took his place on the jump seat. We started the engines and after finishing the after start and beginning the taxi check we began to pay attention to the process of seeing if the steering system was working correctly or not. The flying pilot checked the brakes and then moved the tiller back and forth; slowly allowing the aircraft to move forward while a mechanic walked backwards on the right side of the aircraft watching me and the nose wheel as we moved. We moved from the center of the ramp and decided that the steering seemed to be working fairly normally for that part of the taxi check. During this process I kept my eyes on the mechanic and watched the right wing tip. After we exited the ramp I finished the taxi check; including an anti-ice check that worked normally; the flying pilot and I discussed flying North; climbing to or toward 10;500 feet; and getting traffic advisories. We finished the line-up check; made the necessary calls on CTAF and took off on runway 08. We climbed out normally and after gaining a safe altitude above the ground (2;000 ft or so) I asked the mechanic on board and the flying pilot if now would be a good time to test the valve on the left engine. The mechanic said it would be and I mistakenly heard the flying pilot say 'Can'. I turned the left engine anti ice on; got a green light and the flying pilot then told me that he had said 'You cannot' because the TAT outside was too warm. I replied that I had thought he said 'You Can'; apologized; and shut off the anti-ice which worked normally. I also glanced at the TAT and made a mental note that it read 13 degrees. (Later the flying pilot and I discussed this point. He said it read 15 degrees and I believe him. At the time we were climbing out rapidly and I can only guess that the temperature may have changed in the process.) He told me it was too warm and that I needed to be careful to look at the temperatures before I turned on the anti-ice. During this time we continued to climb out. I acknowledged this and began communicating with Approach; telling them we were VFR for advisories. They replied and gave me a squawk. As I dealt with inputting the squawk my head was down and I was listening to them talk to some other aircraft. During this time we continued climbing out. After I finished putting in the squawk I looked up; first at our altimeter; 4;800 feet; then outside and saw an aircraft at our 12:30 position moving toward our 12:00. I said; 'traffic' and pushed forward on the yoke of the aircraft because I was afraid that on our current trajectory we might collide with a Beech Bonanza. Our aircraft changed its course and we flew underneath the Bonanza at an altitude of 200-500 feet. If he was at a VFR altitude it would have been 700 feet but it looked closer. It was a few seconds later that the flying pilot found that I had missed turning on the transponder(hence no TCAS) during the taxi check and Approach verified that we had had no mode c during our climb out. As we returned I queried Approach if the Bonanza had been on an IFR flight plan and he said no; that we were both VFR. We returned without incident. There were several factors that led up to this event. The first was that I began watching the mechanic on the ground in order to communicate with him if there was any problem with the steering. There was not; but it took me away from the taxi check; the second item which is the 'transponder' which was a contributing factor later on. Also; I had not been part of the conversation that included the max temperature we are supposed to on turn the anti-ice. (There is an ongoing discussion among pilots concerning 10 degrees C to as warm as 15 Degrees C in the event that icing conditions may be encountered). This led to the next event which was confusion in the cockpit at 2;000 feet or so feet when I asked if 'Now was a good time to check the anti-ice valve' and received a 'Yes' from the mechanic and thought I heard 'Can' from the flying pilot. This led to the next event which was the flying pilot instructing me that it was too warm out to turn on the anti-ice and that I needed to check the TAT first. At that point I did and it was 13 degrees C while continuing to climb out. This led to the next set of circumstances concerning the turned off transponder and the flying pilot who did not see the Bonanza until after I had taken action. Many factors led up to that event; primarily; however; we deviated from the 'normal' processes we use on every flight and had failed to communicate on specifics of the flight.


Synopsis: The Falcon 2000 crew was on a maintenance check flight and was distracted by maintenance checks which resulted in the transponder being left off despite being on the taxi checklist. This led to a near miss with a Bonanza at approximately 5;000 feet; as the TCAS did not work and Approach Control had not yet established radar contact with the Falcon.