Wairau Beacon ► Aviation Series 001
Welcome to my Aviation Series of GeoCaches.
This is a series of caches related to aviation, placed at sites with present-day or historical significance.
Please feel free to share your own experiences or information about the topic in your log.
I hope you learn something new and get a new perspective. Happy hunting!
Wairau NDB (Non-Directional Beacon)
An NDB is a radio transmitting ground station either for aircraft or marine navigation equipment known as an ADF (Automatic Direction Finder).
The antenna emits a Medium Frequency signal on the 100-1750 kHz band for aircraft. The station emits a modulated Morse-Code identifier which spells the 2 character ID code, and this can be audibly heard in the aircraft, or decoded by modern aircraft instruments.
The ADF equipment in the aircraft displays a relative bearing of the ground station relative to the aircraft's heading.
NDB's and ADF's are being phased out worldwide, as they are one of the oldest forms of radio navigation equipment still in use by aircraft. A relative bearing has limited use to aircraft navigation, but it remains a cost effective and reliable form of navigation compared to VOR (VHF). And NDB is more useful when paired with a DME (Distance Measuring Equipment) station, but this adds complexity to the station.
GPS has widely superseded the old technology.
The advantages of NDB's compared to VOR's are:
- Greater range & lower altitude reception;
- Less installed equipment & cheaper;
- Good for long range navigation directly toward or away from the beacon.
The disadvantages:
- Subject to many errors & interferrence;
- Need 2 stations to easily approach the runway in poor visibility;
- Pilot needs to perform extra mental calculations to ascertain their position.
The Wairau NDB station was completely removed sometime between 2007 and 2009.
Today, the site is an empty paddock with no sign of the equipment that once comprised a perimter security fence, electronics shed, central mast, 3 stay wires and concrete anchors.
If anybody has any further information, photos, or charts containing this station, please get in touch. Information online is very limited, pretty much nonexistent.
Westport NDB antenna with electrical equipment in the white shed. Sign reads:
"Westport Non-Directional Beacon and Distance Measuring Equipment. Navigational Aid critical to aircraft flight safety."
ADF instrumentation in a light aircraft. 1630 kHz has been tuned, and the beacon is 60 degrees right of the aircraft nose.
A list of remaining NDB stations in NZ is compiled below (North to South):
KT 0238 kHz -35.028596, 173.242344 Kaitaia
KK 0226 kHz -35.262013, 173.911136 Kerikeri
WR 0326 kHz -35.771324, 174.361885 Whangarei
SF 0366 kHz -35.885358, 174.356903 Springfield
SY 0350 kHz -37.238353, 175.166539 Surrey
WI 0254 kHz -37.267474, 174.811824 Waiuku
TG 0346 kHz -37.677562, 176.191211 Tauranga
WK 0362 kHz -37.924278, 176.915262 Whakatane
AP 0230 kHz -38.743218, 176.074316 Taupo
TM 1630 kHz -38.921540, 175.313746 Taumarunui
WU 0382 kHz -39.959370, 175.026514 Whanganui
PP 0242 kHz -40.902982, 174.983398 Paraparaumu
NL 0358 kHz -41.228783, 174.828221 Newlands
WS 0278 kHz -41.740607, 171.579667 Westport
KI 0350 kHz -42.420333, 173.695500 Kaikoura
HK 0310 kHz -42.729098, 170.956152 Hokitika
TU 0366 kHz -44.308399, 171.225058 Timaru
LX 0386 kHz -45.165500, 169.479833 Alexandra
MI 0358 kHz -45.871395, 170.320002 Mosgiel
HL 0378 kHz -45.945833, 170.162000 Henley
BE 0394 kHz -46.027833, 169.983167 Berridale
PY 0290 kHz -46.155662, 166.612275 Puysegur Point
If you have a radio capable of tuning these bands, have a go at picking up the morse ID, it should match the 2 letter ID listed here.
Cache is located along the public Eckfords Road, next to the site where the NDB station once sat.
The location is directly aligned with the end of Woodbourne runway 24, and you should see aircraft flying overhead if landing into a Westerly wind. There are 3 private residences at the Northern end of this gravel road, but the GZ is rarely muggled.
Have fun!
Special thanks to Kiwimykl for some caching supplies to give me a boost.