Did you do a full 360 degree range test on the ground, engine running? Even with 2.4 it is critical to do a range test (using the reduced TX signal procedure outlined in the Spektrum user's guide) from all aspects...kind of hard to do this from the top or bottom, but rotating the plane through a full 360 degrees while at max range on the ground can help identify any issues. Should be done for all new installations and any time you move/change electronic components.... also, at $24 or so, there is no reason for not using the data logger... just my $.02...at 72 succesful Spektrum jet flights and counting.

Barry