Airplane Systems Flashcards
What three instruments are connected to the pitot/static system?
- Altimeter
- Airspeed
- VSI
ALT, AS, and VSI are all on the pitot/static system, but which one is the only one that is connected to both the pitot tube and the static port?
Airspeed. So if either of these ports is blocked it will affect the airspeed.
How often does the pitot/static system need to be tested for leaks?
Every 24 months (for IFR flights)
What instruments might get messed up if the static port is blocked and what can you do about it?
The VSI, The Altimeter, and the airspeed will all be affected. If you have an alternate static source, switch to it. You could also pull out the static line from under the carpet. You could also smash the glass in the VSI.
What instruments will be affected if the pitot tube gets blocked?
Only the airspeed indicator
What indications happen on the instruments if you stwitch to your alternate static source?
The alternate static souce will have a slightly lower pressure compared to the normal static source.
- The airspeed will read slightly higher
- The ALT may indicate slightly higher
- VSI will momentarily indicate a climb, but then will settle back to its initial indication
What happens if your static port becomes blocked and you dont have or dont switch to an alternate static source?
- Altimeter stops moving entirely. It freezes wherever it is.
- VSI will stay at zero in a climb or descent
- The AS will under-reas as you climb and over-read as you descend
When the static port becomes blocked, why does the AS under-read ( says you are going slower than you are) as you climb and over-read (says you are going faster than you are) as you descend?
As you climb, the pressure in the pitot tube will become less and less with altitude. As a result, the difference between the outside pressure and the static pressure trapped in the static system will have a smaller and smaller difference between it. Which will be indicated as a slower airspeed on your ASI.
The reverse for if you descend.
This means the ASI is not very useful in determining if you have a static block. As you expect your airspeed to inscrease if you pitch the nose down to descend and expect the airspeed to decrease if you pitch up to climb
Some pitot tubes have a drain hole, and some dont. What happens if both are blocked?
Only the ASI is affected by a pitot tube blockage.
Because the ASI now only has the static pressure as info, a fully blocked pitot tube will turn the ASI into an Altimeter. As you climb and the static pressure drops, the airspeed indicator will show an increase in airspeed. As you descend and the pressure increases, it will show a slower airspeed.
As you climb, so will the airspeed. As you descend, so will the airspeed
