Tue Apr 02, 2024 11:41 am
#2015800
Reviving an old thread....
I was manoeuvring just northeast of Banbury yesterday, chasing myself around some clouds. Now if you start a climb in an RV it's not unknown for SkyDemon to go nuts with impending airspace warnings because it doesn't take long on that trajectory before you infringe. You make sure you know where you are and get used to the warnings.
I knew I still had a thousand feet or so of Class G above me and was just levelling off to swing around this particular cloud when SkyDemon upped the ante and declared 'ENTERED DAVENTRY CTA'. I didn't stop to argue with it, closed the throttle and stuffed the nose down.
This was SkyDemon on my iPad, getting position data from my SkyEcho 2.
Was wearing an Oxford FMC and listening out. Sweating a little, I kept the radio and txpndr as they were for long enough for London Control to pick up the phone and say "Oi, Oxford...." and then the radio call to come to me.... but nothing came.
Reviewing the flight later on the ground, there was a big difference between the altitudes on my iPad (SE2) and my phone (internal GPS). They disagreed by about 1,500ft on how high I got. The iPad showed a long climb continuing after entering the CTA, well after I'd stuffed the nose down, and then an almost vertical drop of 2,000ft. The phone showed what I expected - the short steady climb followed by levelling off then a sudden descent, never getting closer than about 1,000ft from the base of the CTA above.
Yes, yes, yes......low QNH yesterday. But the CTA it thinks I infringed is defined by an altitude, not a flight level. The profile on the iPad is also implausible - you can't dive an RV that quickly without getting to about twice VNE.
My take on it is the SE2 had a brain fart of some sort. Another good reason to keep my phone going as a backup.
Schrödinger's cat walks into a bar. And doesn't.