My pitot and static are two probes under the wing – when parked I always cover them, but despite that I’ve had two occasions of blocked static port, and it was nothing like the text book.
The issue was (on both occasions) that a drop of water had got in (maybe condensation) and ended up at the elbow in the piping under the wing. We are told that with a blocked static port, the altimeter won’t work and the airspeed needle will go down as you climb. However, with a drop of water (basically, a mobile blockage), both airspeed and altimeter will work just fine on the climb out with the nose pitched up. But when you descend, the drop of water rolls into position to block the static port, and then only temporarily (blocking and unblocking) so the airspeed needle wobbles about and tends to over-read, and the altimeter needle wobbles as you descend. Eventually it seems the drop of water settles, usually in the last 100 feet before landing, at which point the ASI just sticks at whatever it was reading. Then as the tail comes down on landing, the drop moves out the way, and the ASI needle falls to zero.
Don’t tell the LAA this, but as both pitot static lines come out at the wing root, accessible from the pilots seat, my in-flight solution the second occasion it happened (and I knew what was up!) was to just pull the static tube off the wing root fitting to act as an impromptu alternate static source!
NealCS wrote:
the article below suggests it is fixed in the new “max” version at least (…) Any updates on the original 1000s would be nice to see
I think the update is actually a upgrade to the “max” version, for a discounted price below the price of a new “max” unit. See prices for new vs upgrade on https://aspenavionics.com/news/aspen-avionics-receives-easa-approval-for-evolution-max-primary-flight-and-multi-function-displays/
And it just only has been approved for EASA-registered planes, apparently.
Peter wrote:
It’s important to take great care of static vents, by putting the plugs in after every landing. It’s obvious, from casually looking around airports, that most people don’t do that. Eventually you get a blockage due to hundreds of dead creepy crawlies.
Typically, it works our OK, especially if the a/c is flown (almost) daily. But if the runway is closed for a week during a hot summer, then everyone realises that yes, it happens…
We had static plugs for the Robin and used them religiously. The opening was about 3.5mm and we used new split pins, with flags on a keyring.
On 2 occasions of forgetting we experienced blockages.
The 1st time was very specific. We parked away for the weekend and on returning the wife said oh you forgot the static plugs, and I acknowledged then carried on. On the way back we had issues develop. The maintenance guys confirmed a partial blockage.
It seemed ridiculously unlucky.
Then one day, and another, some years later, something happened.
We were in Summer and by the aircraft, when we noticed an insect land near the static, wander around for a moment and head right for the opening.
We concluded that maybe the paint scheme had an impact on where an insect may settle.
It is not usual for SEP aircraft to plug the static ports. The TB20 is pretty much the only one where such plugs are supplied with the aircraft by the factory. All other SEPs don‘t have this, get parked both inside and outside, and very rarely develop static line problems. A few aircraft have static drain points, to get rid of water. Most others don‘t.
I have had the Aera 660 in the yoke for about 2 years and it’s a nice box. I didn’t even know it had those extra features 
I wonder how common an ASI failure is? I think it could trip up quite a lot of people, especially if the issue is not very obvious. Luckily the pitot-static system is very simple and rarely fails.
It’s important to take great care of static vents, by putting the plugs in after every landing. It’s obvious, from casually looking around airports, that most people don’t do that. Eventually you get a blockage due to hundreds of dead creepy crawlies.
Malibuflyer wrote:
How much workload in a cockpit does it take to “forget” that he “airspeed-tape” on the RHS actually does not show airspeed?
I had the ASI blocked once (the static), leaving me only with the GS on an older Garmin GPS. Very peculiar experience as the ASI seemed to work perfectly at first, but started to wander all over the place when climbing. Not at all what you would expect from reading text books about the ASI instrument and how they work. Decided to circle around and land using the GPS. At no point did I forget that the GPS shows GS.
Do a big circle at a (relatively) low altitude? That way you know where the wind is coming from (compass heading with lowest G/S) and then you do (fastest-slowest)/2=W/S TAS, of course at an altitude. And you know that IAS (or CAS) = TAS/1.02 for every 1k ft.
Perfect! Simple when you point it out! I’ll remember that :)
NealCS wrote:
I suppose one could judge the wind aloft using the stall warner
Do a big circle at a (relatively) low altitude? That way you know where the wind is coming from (compass heading with lowest G/S) and then you do (fastest-slowest)/2=W/S TAS, of course at an altitude. And you know that IAS (or CAS) = TAS/1.02 for every 1k ft.
NealCS wrote:
I’m going to add a reminder placard to the Aera emphasising “ground-speed”
Like that very much !!!
