How is VNAV calculated?

How is VNAV calculated?

The VNAV path is computed using aircraft performance, approach constraints, weather data, and aircraft weight. The approach path is computed from the top of descent point to the end of descent waypoint, which is typically the runway or missed approach point.

What should the altimeter setting be?

All operators will set 29.92 “Hg. (standard setting) in the barometric altimeter. The lowest usable flight level is determined by the atmospheric pressure in the area of operation as shown in TBL 7-2-1. Air Traffic Control (ATC) will assign this flight level.

How do you read the altitude on an altimeter using the hands?

Indicated altitude is simply what the hands on the altimeter point to. The long hand reads hundreds of feet (the calibrations are 20 feet), the next largest hand reads thousands of feet, and the third indicator reads in tens of thousands.

What is VNAV mode?

VNAV stands for Vertical Navigation and is an autopilot feature that allows the aircraft to adjust vertical speed to meet a predetermined altitude at a specified waypoint.

What does a high altimeter setting mean?

When the temperature is warmer than standard, you are higher than your altimeter indicates. When you are flying above a location for which you obtained a local current altimeter setting in extremely cold temperatures, the true altitude of the aircraft can be significantly lower than indicated.

How does altimeter setting work?

The altimeter measures the height of an aircraft above a fixed level. The instrument senses this by taking the ambient air pressure from the static port. As the aircraft goes up, the pressure inside the case decreases and the bellows expand. The opposite happens as the aircraft descends.

Is the barometric altimeter the same as LNAV + V?

LNAV+V is not the same as LNAV/VNAV or LPV. Pilots must use the barometric altimeter as the primary altitude reference to meet all altitude restrictions. Advisory vertical guidance is not required and is an optional capability.

How is the altitude of an RNAV approach determined?

Altitudes for each segment of the approach, for any stepdowns, and for the minimum altitude are dictated by the barometric altimeter. In other words, whether we fly an RNAV approach to a DA or an MDA, that altitude is determined by the altimeter, not by the GPS. LNAV approaches may offer advisory vertical guidance (+VNAV).

What does ENR 1.8 cold temperature barometric altimeter mean?

When the ambient temperature is warmer than the standard day, the aircraft’s true altitude is higher than the indicated barometric altitude. TBL ENR 1.8-1 indicates how much error may exist when operating in non-standard cold temperatures.

When to use RNAV or baro-VNAV approach?

The uncompensated baro-VNAV chart note and temperature range on an RNAV (RNP) approach applies to the entire procedure. For aircraft without a baro-VNAV and temperature compensating system, the RNAV (RNP) approach is not authorized when the actual temperature is above or below the charted uncompensated baro-VNAV temperature range.