What is a VSI instrument?
A Vertical Speed Indicator (VSI), also known as a Rate of Climb and Descent Indicator (RCDI) is an instrument which indicates the rate of climb or descent of an aircraft.
What does a VSI do?
Vertical speed indicators (VSI) measure the change in static pressure due to a change in altitude and present this information as the rate of climb or descent.
What are the types of VSI?
The VSI can go by many different names to include:
- Variometer.
- Rate of Climb Indicator.
- Vertical Velocity Indicator.
- Vertical Speed Indicator (VSI) is however, most common.
How is VSI calculated?
If one degree equals 100 ft/nm, then our VSI can be calculated numerous ways:
- VSI for 1° pitch change = NM/MIN X 100 FT.
- VSI = (Pitch Angle) X (NM/MIN X 100)
- VSI = (Gradient) X (NM/MIN) = (FT/NM) X (NM/MIN)
Is a VSI required for IFR?
Vertical Speed Indicator Of the conventional six-pack of flight instruments, it’s the only one not legally required for IFR.
How does the calibrated leak work in a VSI?
The calibrated leak is a tiny hole that connects the casing of the VSI to the static source, but there’s a catch. The hole in the calibrated leak is small enough that is restrict airflow, so it can’t move in and out as fast as the diaphragm can.
How do I adjust my vertical speed indicator?
The needle of the vertical velocity indicator should indicate zero when the aircraft is on the ground or maintaining a constant pressure level in-flight. Most instruments can be adjusted to a zero reading by turning a screw on the lower left corner of the instrument case.
Is a VSI required?
If you’re not operating under a Minimum Equipment List that requires one, and the typical General Aviation pilot in the USA is not, then “No” is the answer to your posted question. There is no requirement for a VSI under FAR 91.205 hence no specific VSI inspection requirement is stated.
Is the VSI required for IFR?
Of course; a VSI is not required equipment for VFR or IFR flight. Tape a note or label on it (“INOPERATIVE”), and go flying. (A VSI has no power source and merely relies on changing static pressure).
What is the difference between altimeter and vertical speed indicator?
The altimeter, which displays altitude in feet, uses static pressure to sense pressure changes. The vertical speed indicator measures static pressure differential to display rate of climb or descent in feet per minute.
Can you fly without VSI?
Can you still fly? Of course; a VSI is not required equipment for VFR or IFR flight. Tape a note or label on it (“INOPERATIVE”), and go flying. (A VSI has no power source and merely relies on changing static pressure).