Date: 201706
Local time of day: 1801-2400
Location: ZFW.ARTCC, TX
Flight conditions: Mixed
Weather elements / visibility: Thunderstorm; Rain; Turbulence; 6000
Light: Night
Aircraft: PA-44 Seminole/Turbo Seminole
Operator: FBO
Operating under: Part 91
Flight plan: VFR
Mission: Training
Flight phase: Cruise
Airspace: Class E ZFW
ATC / advisory: Center ZFW
Reporter organization: FBO
Reporter function: Pilot Flying; Trainee
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Private
Human factors: Training / Qualification; Situational Awareness
Anomaly: Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Contributing factors: Weather; Human Factors
Primary problem: Weather

Narrative: This flight was undertaken to satisfy the cross country commercial training required by 14 CFR 61.129(b)(4); which is PIC training time. During preflight planning; the instructor and I observed active convective SIGMETs along our route of flight. We each obtained a weather briefing; the instructor via 1800WXbrief.com and I through ForeFlight/DUATS. The briefings showed heavy precipitation and cloud development on radar returns surrounding the route of flight; but not directly along our route. We reviewed radar returns immediately prior to our flight via the display layer on ForeFlight; and concurred that our filed route was clear of all depicted returns/echos. We were attempting to accomplish the flight in VMC to satisfy the aforementioned FAR (b)(4) requirements; but at my insistence we filed an IFR flight plan. Both pilots as well as the plane were IFR equipped and current.Immediately after takeoff; Shreveport's departure/approach control advised us of moderate to extreme precip/echos along our route. We were equipped with an aftermarket ADS-B IN receiver that was based on a Raspberry PI and the open source Stratux software; which is substantially cheaper than the branded Stratus product. We advised the approach controller that we had limited composite radar display on our iPads from the Stratux and that it was on a delay. We also inquired as to the weather capability of approach and the facilities we would be handed off to; and were informed that Ft. Worth center had much better weather detection equipment. As we received updates on our iPads; we noted a difference between the radar displays of each iPad. Because the instructor's iPad was more closely representative of the weather we could visually observe; and the instructor was more familiar with his system; we elected to rely on his iPad. We noted a severe/extreme cell to the right of our route of flight; and a smaller moderate cell to our left. We were confident that; at the time we were handed off to Ft. Worth; the gap between the two cells was large enough for us to safely continue our route as planned.As we continued our flight and neared the cells; the center controller continuously updated us on the position of the cells in front of us; and we did not fully understand his attempt to convey to us the danger ahead. The instructor's iPad showed a gap between the cells that we were less enthused about; but still considered safe. We began to be able to see the cells and; during flashes of lightning; we could finally see the gap that was depicted on our iPads. Because of the nature of the instruction at our school; which has been described as a 'pilot mill;' we generally undertake very low risk flights. We were confident in our 'book' or academic knowledge of thunderstorms; but we have very little exposure to operations around actual thunderstorms. As a result; we felt we were still operating safely and had a good enough margin between the cells. We also failed to notice the rapidly increasing convergence between the two cells.We were committed to shooting the gap and were not considering alternative options. As we got closer and the lightning intensified; we became increasingly nervous. I have watched all the videos the AOPA Safety Institute has made publicly available; and I increasingly felt as though I was the subject of one of their videos. When the controller advised us that we could turn to our 9 o'clock and divert 60 nm we immediately took his advice; and shortly thereafter the controller informed us the two cells had merged. We encountered moderate turbulence during our diversion; and had the controller not given us the advice he did; we would have continued our flight into the core of the merged thunderstorm; which was at least severe turbulence. We immediately realized we had been accepting a large amount of risk for very little reward.We had attempted to conduct the same flight the night prior; but the forecast weather was very poor. That night turned out much better than the forecast; however; and we were similarly expecting the weather to turn out better. In addition; we were both feeling the external pressures of our flight school's training time line/syllabus. When a student starts at this school; expectations are put on both the instructor and student to finish within a specified time frame. Due to weather and other uncontrollable factors; I began to fall behind the expected syllabus. This caused us to underestimate the convective sigmet and the potential for other convective activity to build in the region. I often err on the side of caution in go/no-go decisions; but the fact that we were away from home also added another external pressure. Neither my instructor nor I had brought an overnight bag when we departed and we had not considered an overnight stay in SHV. During our debrief; we both agreed that had this been the departure flight from our home airport; we would have been more conservative in our decision. It's very different to read about decision making; thunderstorms; and get-there-itis; and experience it firsthand. Thanks to the help of the Controller; we were able to realize our errors and risky decisions before they became fatal.




Synopsis: PA44 commercial student with an instructor reported attempting to navigate through thunderstorms using their iPad's displaying Nexrad images.