Is Thornleigh under a flight path?

Yes — Thornleigh is under Sydney Kingsford Smith Airport flight paths, with around 13 overflights on a typical day, mostly arrivals.

Which airport's aircraft fly over Thornleigh?

More than one source: Sydney Kingsford Smith Airport (~11/day), other low-flying aircraft (~2/day). The breakdown above shows each source's pattern.

What time do planes start over Thornleigh?

The first movements typically pass over Thornleigh around 9:31am, once the curfew (11 PM – 6 AM) ends. Traffic builds through the morning peak.

Is it quieter in Thornleigh on weekends?

Slightly — weekends average about 34% fewer overflights than weekdays (14 vs 21 a day).

Do planes fly over Thornleigh at night?

The main airport's curfew restricts movements between 11 PM – 6 AM, so overnight overflights are rare. The last movements are typically around 9:03pm.

Aircraft noise in Thornleigh (2120)

On a typical day, about 13 aircraft pass over Thornleigh — mostly arrivals at Sydney Kingsford Smith Airport, between roughly 3,000 and 5,000 ft. Helicopters and light aircraft add another 2 low overflights a day. Estimated peak ground noise reaches 78–81 dB. It ranks #99 of 139 Sydney suburbs for aircraft noise exposure. (Flight Path Noise monitoring data, 90 days to 2026-08-21.)

Data: 90 days to 2026-08-21 · all tracked aircraft over Thornleigh · updated monthly

Overflights / day

busiest on Fridays

Typical altitude

3,100 ft

over the suburb

Est. peak noise

78–81 dB

under the flight path, modelled

Sydney rank

#99 / 139

louder than 29% of measured suburbs

A typical day of overflights (all sources)

12a6a12p6p

First movement ~9:31amBusiest hour 5pmLast movement ~9:03pm

Where the noise comes from

Thornleigh hears traffic from 2 distinct sources:

Sydney Kingsford Smith Airport

live map →

11 overflights/day (87%) · typically 3,200 ft

Thornleigh lies at the far edge of the northern arrival flow, where descending traffic passes at moderate altitude toward the sequence. The stream is steady on south-flow days and thin otherwise; altitude keeps it comfortably in the background most of the time.

Helicopters & other light aircraft

2 overflights/day (13%) · typically 2,500 ft

Around 2 low overflights a day come from aircraft not operating at a tracked airport — helicopters, seaplanes and light aircraft transiting the area. Light-aircraft counts are tracked overflights only — many training and private aircraft carry no ADS-B transponder, so true numbers are higher.

Light-aircraft counts are tracked overflights only — many training and private aircraft carry no ADS-B transponder, so true numbers are higher.

How nearby suburbs compare

Suburb	Overflights / day	Rank
Wahroonga	24	#49
Pennant Hills	24	#50
Thornleigh	13	#99
Normanhurst	6	#130
Cheltenham	6	#132

Common questions

Is Thornleigh under a flight path?: Yes — Thornleigh is under Sydney Kingsford Smith Airport flight paths, with around 13 overflights on a typical day, mostly arrivals.
Which airport's aircraft fly over Thornleigh?: More than one source: Sydney Kingsford Smith Airport (~11/day), other low-flying aircraft (~2/day). The breakdown above shows each source's pattern.
What time do planes start over Thornleigh?: The first movements typically pass over Thornleigh around 9:31am, once the curfew (11 PM – 6 AM) ends. Traffic builds through the morning peak.
Is it quieter in Thornleigh on weekends?: Slightly — weekends average about 34% fewer overflights than weekdays (14 vs 21 a day).
Do planes fly over Thornleigh at night?: The main airport's curfew restricts movements between 11 PM – 6 AM, so overnight overflights are rare. The last movements are typically around 9:03pm.

Checking a specific address?

This page shows suburb-wide averages. An address report gives you the exact overflight count, altitudes, hourly pattern and noise estimate for one property. Leave your email and we'll let you know when reports are ready for Thornleigh.