Peter wrote:
Despite a huge UK readership here, nobody mentioned this option on the other thread; presumably for a reason.
I did (but mentioned iOS). You can get monthly subscriptions, it costs 12 pounds, seems like you should just try!
What algorithm does SD use for terrain warnings? The G496 projects current track for 2 mins, with some allowance for a known airport approach path. There is also an unconditional “five hundred” warning which is really good.
Does anyone know the above?
Details are here http://www.skydemon.aero/help/manual.pdf page73/75
I use SD on a nexus 7 with a homemade mount using a “case” (specific to nexus 7) attached to a RAM yoke mount, I find this fits comfortably without obscuring other instruments. It’s networked to a Pilotaware which displays traffic and has an audio out which feeds my lightspeed headset.
Regards
Pete
Hello,
the Sky-Map app on the iPad/iphone does a visual and audio warning “airspace ahead” and shows it nicely on the moving map. It can be connected via aux to the audiosystem or via Bluetooth to a compatible headset like the Lightspeed Zulu. We have even the traffic warnings from Powerflarm send to the audio via the iPad mini.
The app is however rather limited to VFR maps which come by subscription.
Thomas
Moving on to IFR
What sort of cost is involved?
I have introduced Skydemon to about 6 pilots.
As a combo flight-prep / in-flight nav-aid / airspace avoidance tool / NOTAM / Met / AIP front end / etc, it has no equal. It really shines when coming in, descending from controlled airspace to uncontrolled VFR fields or vice-versa. I have it on a 7" tablet, and running on my Android phone as a backup. IFR plans come in via Autorouter, VFR plans direct in SD.
Further digging suggests that airspace warnings have a fundamental problem in implementation:
CAS whose base is defined as an altitude could just use the GPS altitude provided the app corrects for the geoid error which on most mobile devices is about 160ft in N Europe.
CAS whose base is defined as a flight level can use the GPS altitude but also needs user input of the local QNH and a button telling the app one is flying at a flight level.
Current implementations appear to deal with this by using a generous buffer of say 500ft but that means you will get constant warnings in say south east UK where the MSA might be 2000ft and the CAS base is 2500ft, so people have to fly at ~ 2300ft. But even 500ft won’t be enough if the QNH is far enough away from 1013.
Terrain warnings don’t have this problem. They can use just GPS altitude and the geoid error is not a problem because you should not be so close. Proper aviation boxes like the G496, and all panel mounted IFR boxes, have the geoid correction and are accurate to 10-20ft IME.
iPhone 6 and later have an integrated barometer. I do not know if any of the apps make use of it and whether other Android phones/tablets are equipped with such a sensor.
I think your QNH problem is mostly hypothetical.
The baro pressure in a cockpit is somewhat off, due to aerodynamic effects. Try the alternate static one day… could be 100ft off.
I don’t think implementing this is a problem but it needs to be done right and you need a tight margin on the warnings to avoid constant beeping.
