Aviation occurrence briefs

Flight below lowest safe altitude involving a Piper PA-28-140, Archerfield, Qld, on 18 October 2019

Status: Completed
Investigation completed


Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation.

What happened

On 18 October 2019, a Piper PA-28-140 operated a private return flight from Archerfield, Queensland to Narrabri, New South Wales with one pilot on board. The flight was to be operated under visual flight rules (VFR)[1] by day.

At 1915 Eastern Daylight Time, the aircraft returned to Archerfield after last light[2] at 1,500 ft, which was below the lower safe altitude (LSALT) of 2,900 ft that is applied after last light. Air traffic control subsequently issued a safety alert to the pilot.

Pilot comments

At the time of the occurrence, the pilot was yet to undertake night VFR and instrument flight rules training. He had planned to arrive back at Archerfield before last light, however had miscalculated the time and had a subsequent delayed departure from Narrabri. The pilot was unaware of the night VFR procedures for Archerfield, in particular the LSALT and therefore the approach was flown at 1,500 ft as per day VFR procedures.

The pilot advised that in response to this occurrence he plans to undertake night VFR training.

Safety message

This incident highlights the need for pilots to carry out thorough flight planning and have an understanding of the risks associated with flying at night. Further information on the risks inherent to visual flight at night can be found in the ATSB publication, Avoidable Accidents No. 7 - Visual flight at night accidents: What you can't see can still hurt you.

It is recommended that VFR pilots should also use a personal minimums checklist to identify and manage risk factors. A personal minimums checklist is an individual pilot’s own set of rules and criteria for deciding if and under what conditions to fly or to continue flying based on their knowledge, skills and experience.


The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the safety concerns is inflight decision making.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.


  1. Visual Flight Rules (VFR) are the rules that govern the operation of aircraft in Visual Meteorological Conditions (VMC) (conditions in which flight solely by visual reference is possible).
  2. Last light is regarded as the time when the ambient light value falls below that required for aircraft operating underday visual flight rules and is defined as the time when the setting sun is six degrees below the western horizon.
General details
Date: 18 October 2019   Investigation status: Completed  
Time: 1915 EST    
Location   (show map): Archerfield    
State: Queensland    
Release Date: 28 November 2019   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Piper Aircraft Corp  
Aircraft model PA-28-140  
Type of operation Private  
Sector Piston  
Damage to aircraft Nil  
Departure point Archerfield, Queensland  
Destination Narrabri, New South Wales  
Last update 28 November 2019