Terminal area aircraft navigation (RNAV) systems are required to maintain an accuracy
of less than 1 nautical mile for 95 percent of the total flight time.

RNAV delivers precisely positioned and more orderly air traffic flow
without the need for radar vectoring.

Aircraft arrivals at most large airports are sequenced by Air Traffic Control,
who will often direct RNAV equipped aircraft to follow a
STandard instrument ARival procedure or STAR.

Southern and western arrivals into Sydney airport often follow the Rivet 3 RNAV STAR.

The observatory from where the above image was taken is located just south
of the arrival waypoint labelled "Boogi" in the chart below.

Aircraft following the Rivet 3 arrival are consistently 6000 feet above
and less than nautical mile from the Observatory....
and by co-incidence.... at a very similar attitude of the Sun when viewed
from 9:30 to 11:00am in early November and again in late February.

Given the right location and time of year, aircraft transiting the solar disk are not unusual,
yet there were many failed attempts to catch the "perfect" transit (e.g. below)

The images above were made by aligning several frames on the silhouette a transiting aircraft,
rather than images of the Sun. By doing so, the successive frames reveal
the complete profile of the passing jet.

FYI: The photographer and author is also a retired International Airline Pilot
has personally flown this arrival into Sydney many times during his 36 year aviation career.

Astro-Physics AP130GTX + AP BARCON
Coronado 90mm Double-stack etalons + BF30
QHY533M

STAR Chart Copyright Jeppesen 2020. Do not use for operations.

Image and Text Copyright Peter J Ward 2025