Not being from the “big iron” side of the fence, I was hesitant to post. However, curiosity got the best of me as I did not see any discussion about the cockpit displays.
What kind of visual references / information (route, traffic, terrain, etc.) would the pilots have seen on their respective PFD’s and MFD’s?
We have been interfacing Sky Watch (TCAS system) data to Garmin 430’s which allow for a visual, layered digital reference to the “outside” space around the aircraft.
What really sticks out to me, aside from all the other issues, is that 2 modern, independent TCAS / XPNDR systems failed to “see” the threat. I don’t know what TCAS range settings are used at FL370, however, it just seems unfathomable that someone didn’t see something at one point in time.
This brings me to another question…
Can a TCAS / XPNDR signal be interfered with by an outside source?
We have to perform a number of EMI tests anytime a new type of equipment is installed to ensure there is no adverse interference with critical systems. However, these tests are only required for items installed on that particular aircraft, with no checks performed using outside signal sources. I can recall back when digital controls were entering the civilian market and one particular engine mfg. used a digital overspeed controller that worked great except when you flew by a high power tension line which put out enough EMI to trip the overspeed control and decel the engine to idle.
As stated previously, the aircraft were in a military control zone, and the Legacy did land on a hidden air force base. I am not a “spark chaser” so maybe I am off track, but I have seen where some simple outside signals played hell on equipment displays, and caused a lot of grief to the mechanics troubleshooting the problem.