Pilots can be the first to notice the early signs of activity from a reawakening or erupting of our volcanoes. How do you report it? And what are the steps to stay safe when these sleepy giants stir?
With emissions of steam and gas from Whakaari/White Island increasing recently, it’s a timely reminder for aviators in Aotearoa to be aware of the latest hazard information so they can operate safely around our volcanic regions.
CAA Chief Meteorologist Paula Acethorp says,
“Pilots are often in a great position to see the earliest indicators of a volcanic eruption from an active volcano in the North Island. They’re well-placed to be an effective early warning prompt, contributing details that help to prime the emergency response system for action.”
What to do
Paula says, “If you see a volcanic plume (a grey or brown cloud emitted from the volcano), submit a Pilot Report (PIREP) describing the activity, including plume height and direction.”
CAA Inspector Terry Curtis became familiar with flying in volcanic areas in his days as a commercial pilot in New Zealand and overseas.
“The best thing to do is to stay well away from a volcanic plume if you spot one,” he advises.
If you inadvertently fly into a plume, it can make the air look brown-tinged and hazy, with a strong smell of sulphur.
You should exit as quickly as possible, Terry says, because volcanic ash may extend for several hundred miles.
“The quickest way out of the ash may require an immediate 180-degree turn.”
Trying to climb above the volcanic ash cloud isn’t recommended because of accelerated engine damage/flameout at high thrust settings.
When you land, Paula advises you fill out a Volcanic Activity Report (VAR) to describe the effects you observed during the encounter.
Volcanic Activity Report (VAR) [PDF 144 KB]
Complete the form and email it to vaac@metservice.com.
“This provides critical information to the Wellington Volcanic Ash Advisory Centre (VAAC) and GNS Science to help in their volcano monitoring and responses,” Paula says.
MetService is the host agency for the Wellington VAAC, one of nine in a global network designated by the International Civil Aviation Association (ICAO).
These centres monitor volcanic activity and issue Volcanic Ash Advisories (VAAs) for airborne volcanic ash, which are then translated into flight information and region-specific volcanic ash SIGMETs.
Check before you fly
Ramon Oosterkamp, MetService’s General Manager of Forecasting, Science and Innovation, emphasises the importance of checking current NOTAMs, the NZ SIGWX chart and any SIGMETs or VAAs as part of your flight planning.
“VAAs and volcanic ash SIGMETs provide pilots with the targeted information they need to fly safely when there’s volcanic ash in the atmosphere.”
This information, along with other core weather reports for aviators, is available in the PreFlight app for New Zealand pilots, at gopreflight.co.nz
GNS Science volcanologist Brad Scott says, “It’s also a good idea for pilots to download the GeoNet app, as part of their preparation before flying in our volcanic regions. The app provides alerts announcing any new Volcanic Activity Bulletins (VABs)* – just make sure the volcano notifications are turned on.”
He adds that the GeoNet webcams can help build up a picture of the weather you’ll be flying in, if you use them in tandem with current forecasts and observations.
Volcanic ash is the biggest risk
The biggest threat active volcanoes pose to aviation is volcanic ash. These abrasive, sometimes microscopic particles can affect aircraft hundreds of nautical miles from the volcano.
According to ICAO, volcanic emissions can be a serious threat to aircraft operations because of the effect of corrosive gases and abrasive particles on aircraft engines and airframes. The effects can include loss of engine performance, flameout, instrument and radio failures and visibility problems.
And of course, volcanic ash can close aerodromes and impact other ground-based infrastructure, interrupting flight schedules and causing temporary chaos.
Importantly, sudden eruptions are hard to predict, even after alert levels are raised.
How hazard zones help pilots
The New Zealand Volcanic Ash Advisory System (VAAS) describes how volcanic activity information is shared across the aviation system. It’s supported by MetService, GNS Science, Airways NZ and aircraft operators. The CAA’s role includes the designation of volcanic hazard zones (VHZs) which are unique to New Zealand.
The VHZs are designed to provide increased protection to aviators from the immediate dangers of volcanic activity.
The CAA originally introduced five VHZs after the Ruapehu eruption in 1995 (Ruapehu, Tongariro, Ngāuruhoe, Raoul Island and Whaakari/White Island).
A VHZ is designated for a volcano under the New Zealand airspace management system. The airspace is usually permanent and is published in the Aeronautical Information Publication New Zealand (AIPNZ) and on Visual Navigation Charts.
Within a VHZ, pilots need to operate in VMC by day, so they can observe any volcanic ejecta or ash plume. It’s vital they keep abreast of relevant NOTAMs (which describe the VHZ size and advise the current Volcanic Alert Level) and, in the event of ash emission, check for SIGMET information.
*Volcanic Activity Bulletins, issued through the GeoNet app, contain the current Aviation Colour Code (ACC), along with the Volcanic Alert Level, and a summary of activity at the volcano which can provide information about potential flight hazards. The ACC is a quick reference only. It refers to the status of the volcano itself, and not the airspace around or downwind of the volcano. That information will be contained in a SIGMET and VAA, if volcanic ash is present.
More information
GAP booklet: Flying around volcanoes [PDF 3.6 MB]
CAA website: Volcanic hazards information and resources
Volcano status information: geonet.org.nz(external link) (or download the app)
GNS Science: Information about New Zealand volcanoes(external link)
GNS Science: Volcanic ash information(external link)
Footnote:
Photo: Whakaari/White Island from iStock.com/jacquesvandinteren