A recent close call highlights the risks of flying VFR in darkness.
In October 2023, two fixed-wing aircraft – a Beech and a Cessna – were attempting a night landing at the same time at Ardmore Airport near Auckland.
The aircraft were flying at different vertical profiles on final. Neither was aware of their proximity to the other.
On final, the Beech flew over the top of the Cessna – missing it, the Cessna pilot said, by just 20 feet.
The Cessna then aborted its approach for a go-around. Both aircraft landed without further incident.
The subsequent Transport Accident Investigation Commission investigation1 found the pilot and instructor of the Beech remained unaware that they’d flown in close proximity to another aircraft.
TAIC noted that the pilot flying the Beech, and the instructor, had developed “an inaccurate mental model of the circuit, and their situational awareness became compromised”.
The TAIC report also noted that situational awareness “requires an accurate understanding of the current operational environment in order to anticipate a future state”. TAIC also said that it requires scanning the environment to gather information using one’s senses. “If information is not detected or if it is misperceived, situational awareness will be affected.”
Of course, this applies to all flying, but building an accurate mental model of what’s going on during a VFR night flight is particularly challenging.
The calm of the night – and its dangers
CAA Inspector Adrian Parker is a former military and police pilot. He knows first-hand, and more than most, the attraction – and dangers – of night flying.
“There are things about night flying, which you just cannot experience flying during the day.
“It can be extremely beautiful and calm.”
But, after many years flying at night over featureless, sparsely populated, flat desert, with just the occasional campfire and stars for light, Adrian is also aware of the great threats inherent in VFR night flying.
“The most dangerous threat is to a pilot’s vision,” he says, “and therefore to their situational awareness.
“In the dark of night when we can’t see details outside the cockpit, we have almost no colour perception, our visual acuity is reduced, and the risk of being tricked by our senses is much greater than flying during the day.
“Our ability to see contrast differences between an image and the background is totally degraded. And anything that diminishes contrast makes it hard to distinguish objects that we use to orientate ourselves in space. When we lose those outside visual cues, there’s also a high risk of spatial disorientation.”
Adrian adds that darkness also creates visual and spatial illusions, often providing misleading information, and the loss of visual references.
“The simplest night illusion is ground light confusion, when a pilot confuses low intensity ground lights with stars.
“This type of confusion has led to controlled flight into terrain, which is actually the most common type of accident at night. It happens when pilots try to fly by visual references and apply VFR standards to night flight.”
While the CAA recommends that VFR pilots regularly refer to their instruments – even when external lighting is providing good visual cues – Adrian believes undertaking specific IFR training is the best advice he can give to pilots to ensure they stay safe.
“When you’re flying with little, or no, moonlight, no visible horizon, and over a dark and remote location, you’re entering IFR conditions – and I believe you really need IFR skills to stay safe. What happens when the moon you’re relying on as your light source suddenly nips behind a cloud? Things can get bad very quickly.
“The best option is to get an instrument rating and keep it current. That way, you’ll be prepared for VFR into inadvertent IMC during any night flight – or during any daytime one.”
Night MET
“When it comes to planning for a night flight,” says CAA’s Chief Meteorologist Paula Acethorp, “reviewing weather information needs an even more critical eye than for a daylight flight.
“Products like the relevant aerodrome TAF and the Graphical Aviation Forecast will give you an indication of whether you’re likely to see the stars – or if there’s a chance of entering IMC.
“And of course, satellite imagery will tell you what’s already in the area, and potentially show what might be moving in.”
Paula advises that many webcams at aerodromes have a night-time mode that makes the most of any ambient light, and so may highlight any areas of cloud.
“Also, when you review the relevant aerodrome weather observations, check how close the dew point temperature is to the air temperature. With clear skies and light winds at night, if the dew point and air temperatures converge, a significant risk of fog or mist forming arises.”
Aerodrome lighting
Aerodromes around the country have begun to replace their old halogen lighting with LEDs.
The brighter lights will make it easier for pilots to locate aerodrome landing strips.
Pilots will have to get used to the brighter lights, says Operations Manager for Hawke’s Bay Airport, Deb Suisted.
“The LEDs provide a more focused and intense light. You can actually see our new lights from Wairoa!
“Some pilots did have difficulty finding the airstrip due to the directional component of the lighting. Basically, the lighting was harder to spot from side-on.
“In response, we’re installing a beacon and supplementary lighting on the airstrip to help guide them in.”
Tips for night flying from an expert
When planning for a VFR night flight, experience has taught Adrian Parker to consider:
- am I proficient enough to do this flight? Do I need a dual night flight refresher? How proficient am I at flying on instruments?
- what terrain will I fly over?
- what ground lighting (from towns, water, bush, farmland for instance) can I expect?
- what moonlight can I expect? Will the moonlight be obscured by cloud or high terrain or mountains?
- what is the cloud cover like? Have I checked the PreFlight weather app?
- what are my diversion options?
- where can I land – and which aerodromes have lighting?
- where could I stay the night? Do I need an overnight bag?
- am I complying with the rules and company/club procedures?
A final note – on radio calls, and lighting
The TAIC investigation into the October 2023 close call found that two opportunities for the pilots of the Cessna and the Beech to identify each other in the circuit via radio, were missed.
TAIC recommended that ‘see and avoid’ should be, “…underpinned by pilots actively listening to all radio calls, processing the details of calls, and then using these to check their mental model of each aircraft’s position in the approach sequence.
“Pilots should request a repeat of any transmission that they cannot understand.”
Regarding lighting, TAIC found that, while the exterior lighting on the Cessna did meet regulations, the Beech pilots later stated they’d had trouble seeing the aircraft in the circuit.
TAIC said that aircraft can be made more conspicuous by fitting approved LED lights.
More information
GAP booklet: Night VFR [PDF 2.1 MB]
Flight Instructor Guide: Night flying
Vector Online: A heads-up on night VFR
Footnotes
1 taic.org.nz/inquiry/ao-2023-011(external link)
Main photo iStock.com/Michael Valdez