Failures covered
- Blocked pitot inlet or drain
- Blocked static port
- Alternate static source
Pressure System
Interactive
Pitot conditions
ASIPITOT − STATIC
Static conditions
ASI
ALT
VSI
PITOT CIRCUITFLOWING
STATIC CIRCUITFLOWING
PITOT EFFECT
The ASI receives live ram pressure.
STATIC EFFECT
ASI, altimeter, and VSI receive live outside static pressure.
Tap a pressure-system condition, then change the flight path and watch the instruments respond.
Instrument Panel
Integrated Pressure System
Live
Pitot-Static Challenge
1Step 1Brief
2Step 2Observe
3Step 3Diagnose
Select Your Diagnosis
Pitot Conditions
FLOWING
Static Conditions
FLOWING
Observe the Instruments
Pitot
Static
ASI
Airspeed
--
Δ --
NORMAL
ALT
Altimeter
--
Δ --
NORMAL
VSI
Vert Speed
--
Δ --
NORMAL
Review & Score
All Levels
0
Correct
0
Attempted
--%
Accuracy
0
Streak
What's happening
Pitot: Normal operation
Static: Normal operation
Pitot-static system reference
- Pitot blocked, drain hole clear
- Ram air can't reach the line, and trapped pressure vents through the still-open drain. The ASI reads toward zero and stops responding to real speed changes. Altimeter and VSI are unaffected — the static system is independent.
- Pitot blocked, drain hole also blocked
- Pressure is sealed in the line at whatever it was when the blockage occurred. While the static source remains unobstructed, climbing makes the ASI increase like an altimeter and descending has the opposite effect. If the static side is also trapped, both ASI pressure inputs are fixed and the ASI freezes instead.
- Static port blocked
- The altimeter freezes at the altitude when the block occurred. The VSI decays to zero and stays there. The ASI, still fed by a live pitot but a frozen static reference, over-reads below the blockage altitude and under-reads above it.
- Alternate static source in use
- Cabin/alternate static pressure typically reads slightly lower than true outside static, so the altimeter and ASI read a bit high, and the VSI shows a momentary climb blip at the moment of switchover.