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Indeed, JD.
The mud wasp is a significant threat in Brisbane at the moment. Our engineers install the pitot covers as soon as we park - even on a 30 minute turn. They are quick little buggers (the wasps).
From memory, we have had 2 instances of unreliable airspeed as a result of mud wasp activity prior to this procedure.
Your remark about safety culture hit the nail on the head [emoji846]
I used to travel with Garuda to Indo. I found cabin crew were helpful, aircraft were clean and generally had better service than Qantas.
With Qantas most flight I went on had stressed cranky cabin staff, aircraft were dirty with seat backs filled with rubbish.
I worked from West Papua to Sumarta and a few spots inbetween, I had no choice than travel with Lion or one of their companies.
You would not guess where I had the mudwasp incident - no, not Brisbane, Redcliffe!Quote:
Originally Posted by Hugh Jars
My Auster had an automatic pitot cover (are you familiar with them?), which was lifted clear by the airflow once the plane was moving at any speed. Unfortunately, I had parked for a few hours facing into wind strong enough to lift the cover off!
Yes JD, they are a great idea when they work. A couple of Cessnas I used to fly had them. Trouble is those sneaky little buggers find the smallest gap, and they’re up there like a rat up a drainpipe...Quote:
Originally Posted by JDNSW
Latest information from Indonesia says the 737's angle of attack indicators were giving conflicting readings as well as the airspeed and altitude readings being conflicting. How does the angle of attack indicator on these work?
Hi JD. If you look at the scematic I posted further up the thread, you’ll see an alpha vane on each side of the nose. The little wing-shaped blade flies through the relative airflow at flying speeds. It stays aligned with the flow as the aircraft changes pitch (AoA) during flight. Those changes are transmitted elecronically and used with air data in the ADIRU’s to give output to the flight instruments (and a bunch of other equipment on the aeroplane).Quote:
Originally Posted by JDNSW
Photo attached of alpha vane (circled) RHS B737NG.https://uploads.tapatalk-cdn.com/201...8295e23b90.jpg
JD, here is a test board on gate 43 in Brisbane, taken yesterday. There are samples of various pitot tubes, as used on the aircraft that might park at that gate.
The idea is to research why the mud wasps do what they do. Info from our engineers is that they prefer a particular tube, but will use any.https://uploads.tapatalk-cdn.com/201...125048a442.jpg
You say it’s a test board.....do they remove them off the plane to be tested??Quote:
Originally Posted by Hugh Jars
I have no idea mate. They’re probably old ones with failed heating elements, or some other defect.
How could they give incorrect/conflicting readings? Presumably in the electronic transmission - sounds a bit as if in this case the angle of attack indicator was replaced, but that did not fix the problem.
Surely the pitot/static system is direct reading, with no intermediate electronics? Perhaps in addition to providing input to other systems.