Is There A Forum Where I Can Ask Questions For PPL Training
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Join Date: Apr 2015
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As sycamore suggests, you can start here.
Join Date: Jun 2002
Location: east ESSEX
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Bear in mind ,if you ask 30 instructors ,you`ll get 35 answers...!"Those that can,do..
Those that can`t,become instructors..
Those that can`t do either,become Examiners"
(or so it seemed at CFS)!
hat,coat,specs...bus is here....
Join Date: Jan 2003
Location: Southampton
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The OP should try and find the answer before asking the question (there is lots of info on the web) and if he \ she doesn't understand what has been found, then ask, saying why they don't understand. Rather than a copy and paste answer, you would likely get an explaination.
It's very easy to reel off answers parrot fashion, but you really need to know how things work. That way, if something like a blocked static port were to happen, you would know why and what to do about it.
It's very easy to reel off answers parrot fashion, but you really need to know how things work. That way, if something like a blocked static port were to happen, you would know why and what to do about it.
Join Date: Jan 2007
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Posts: 147
Originally Posted by tcasdescend
why when the static port is blocked, airspeed will go up if the plane ascend and airspeed will go down if the plane descend.
Join Date: Apr 2009
Location: Phoenix, AZ
Posts: 201
Originally Posted by tcasdescend
Such as why when the static port is blocked, airspeed will go up if the plane ascend and airspeed will go down if the plane descend.
But to help with the original question - ASI simply measures the difference between pitot pressure and static pressure. Pitot presure is static + ram. If you climb at a constant airspeed then pitot = (static + ram) will go down because actual static pressure will reduce, blocked static pressure will remain constant, so indicated airspeed will reduce.
Go here if you want an independent opinion - https://tinyurl.com/yakvs494
I don't know the best place to have asked the question but perhaps here - https://www.pprune.org/private-flying-63/
Join Date: Apr 2009
Location: Phoenix, AZ
Posts: 201
Originally Posted by Pugilistic Animus
The ASI behaves like an altimeter...that is why it increases with climb
Join Date: Nov 1999
Location: UK
Posts: 1,985
To the OP; I would try Professional Pilot Training, under the Wannabes forum. Or maybe Tech Log, under Flight Deck Forums.
As suggested, the Trevor Thom books will give you the answers to such questions, and are well worth investing in for PPL studies.
As suggested, the Trevor Thom books will give you the answers to such questions, and are well worth investing in for PPL studies.
Tabs please !
Join Date: Jun 2004
Location: Biffins Bridge
Posts: 758
The books mentioned above should be viewed as essential. I also have a copy of this little gem on my bookshelf
I commented in the bar recently that when I turned downwind, I felt a massive acceleration due to the strength of the wind. Half an hour's debate then ensued as to whether this was correct. A very good mate with a PhD and I ended up agreeing to differ. This was after a lot of creative thinking and counter-argument.
I suggest you just learn the officially accepted answers to the questions and don't over-think the scenarios. We can't even agree if Bernouille was 100% correct.
I commented in the bar recently that when I turned downwind, I felt a massive acceleration due to the strength of the wind. Half an hour's debate then ensued as to whether this was correct. A very good mate with a PhD and I ended up agreeing to differ. This was after a lot of creative thinking and counter-argument.
I suggest you just learn the officially accepted answers to the questions and don't over-think the scenarios. We can't even agree if Bernouille was 100% correct.
Join Date: Feb 2006
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On the subject of blocked static ports, it's worth remembering that if you break the glass of the VSI (on an unpressurised aircraft), you'll effectively have an alternate static source (if one isn't already fitted).
Join Date: Feb 2000
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Originally Posted by tcasdescend
Such as why when the static port is blocked, airspeed will go up if the plane ascend and airspeed will go down if the plane descend.
Total Pressure from the Pitot Tube is Dynamic+Static, airspeed is proportional to Dynamic Pressure. Static pressure from the static port is fed to the ASI case to effectively cancel out the static pressure from the sensed Total(Pitot) Pressure, if this case static pressure isn't the same then the indication will be in error.
If the static port is blocked, as you climb the pressure in the ASI case will be higher than it should be for the prevailing altitude. The pressure capsule being fed by the pitot tube(Dynamic+Static) is having its expansion limited by the higher pressure in the case therefore the ASI will under-read.
In a descent the static pressure in the case will be lower than it should be so there's less resistance to the expansion of the pressure capsule, hence it over -reads.
Check out the Wannabees forum and the Professional Pilot Training section for a thread on ATPL Theory
Last edited by Specaircrew; 7th Jul 2022 at 10:13.
Join Date: Feb 2011
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Join Date: Nov 2004
Location: UK
Posts: 453
Originally Posted by Pugilistic Animus
The ASI behaves like an altimeter...that is why it increases with climb
The ASI indicates speed by sensing the pitot pressure, which needs the static pressure effectively removed, ie. it indicates the difference between pitot and static pressures.
If the static is blocked, as the aircraft climbs, the pitot pressure will gradually reduce compared to the now incorrect fixed (and higher) static pressure (blocked, remember), so the IAS will decrease despite flying at a constant airspeed. I now see Specaircrew has it right. The rest appear to be a mixture of incorrect, misleading and plain daft answers, none of which are correct.
Be careful who you listen to. Most will prefer to try to give an answer - any answer, even if its totally wrong - just for the 'honour' of being seen to give an answer. Beware of the charlatans! It's a minefield out there!
Join Date: Apr 2009
Location: Phoenix, AZ
Posts: 201
Originally Posted by pilotmike
O. I now see Specaircrew has it right. The rest appear to be a mixture of incorrect, misleading and plain daft answers, none of which are correct.
I say again - "ASI simply measures the difference between pitot pressure and static pressure. Pitot presure is static + ram. If you climb at a constant airspeed then pitot = (static + ram) will go down because actual static pressure will reduce, blocked static pressure will remain constant, so indicated airspeed will reduce."
Last edited by EXDAC; 7th Jul 2022 at 12:17.
Join Date: Jan 2007
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Originally Posted by tcasdescend
Such as why when the static port is blocked, airspeed will go up if the plane ascend and airspeed will go down if the plane descend.
Join Date: Dec 2006
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Originally Posted by tcasdescend
Such as why when the static port is blocked, airspeed will go up if the plane ascend and airspeed will go down if the plane descend.
