Crash Examples

The Route Taken

http://wxmatters.co.nz/sites/default/files/Jim_intro.ogv

On Saturday 09 April 2011 the pilot of ZK-SML, a Dyn’Aero MCR 01 Club microlight was planning to depart North Shore Aerodrome for a non-stop cross country flight to visit his friend, and flying instructor, in Ashburton.

The Dyn’Aero Club is a two-seat fibreglass carbonfibre composite aeroplane. It has a cruise speed of approximately 145 kts and this aircraft, SML, was fitted with long range fuel tanks giving it a theoretical range of 2000 NM.

ARFOR TN VALID 1700 TO 0200 UTC (0600 – 1500 local)
1000 VRB05
3000 VRB05
5000 27005 PS10
7000 24010 PS07
10000 22015 PS03
FZL 12000FT.
VIS 30KM.
CLD AREAS BKN CUSC 2500 TOPS 7500.
WX NIL SIG.

SML was also fitted with an advanced EFIS system with a single display screen and two-axis autopilot.

At 0751, before leaving home, the pilot got an aviation weather briefing from MetFlight.

For the first part of the route the weather was forecast to be fine, with 30 km visibility and scattered cloud clearing in the morning.

Of note, however, is the Area Forecast for the Tasman area:
This indicated cloud over the whole area from 2500 ft with tops at 7000 ft.

ARFOR TN VALID 1700 TO 0200 UTC (0600 – 1500 local)
1000 VRB05
3000 VRB05
5000 27005 PS10
7000 24010 PS07
10000 22015 PS03
FZL 12000FT.
VIS 30KM.
CLD AREAS BKN CUSC 2500 TOPS 7500.
WX NIL SIG.

The Aerodrome Forecasts corroborate this showing the cloud base at Nelson to be broken at 3000 ft for the entire TAF period and the cloud base at Woodbourne to be broken at 2000 ft.

TAF NZNS 082143Z 0821/0912 23005KT 30KM BKN030 BECMG 0823/0901 01010KT BECMG 0908/0910 23005KT TEMPO 0908/0912 BKN006 2000FT WIND VRB05KT =

 

TAF NZWB 082143Z 0821/0912 27005KT 30KM FEW015 BKN020 BECMG 0823/090106010KT BECMG 0906/0908 32010KT TEMPO 0908/0912 BKN006 2000FT WIND 24010KT BECMG 0906/0908 32010KT =

http://wxmatters.co.nz/sites/default/files/Takeoff.mp4

The pilot phoned his friend in Ashburton at approximately 0800 and discussed his intended route. He was told that the weather was fine in Ashburton.

At 1030 the pilot carried out a pre-flight inspection of the aircraft and members of the local aero club watched the aircraft takeoff at approximately 1100.

D'Urville Island

An hour and a half later, at 1235, radar data shows the aircraft tracking from the Hawera area to D’Urville Island.

At 1320 the radar plot shows the aircraft tracking to the eastern side of D’Urville Island at 1200 ft. From here it follows the inlet to French Pass where the radar data is temporarily lost.

At 1339 radar data is regained showing the aircraft in the vicinity of Cape Soucis on a southerly heading at 2500 ft and climbing, radar data is lost again at 1344 with the aircraft approaching the Bryant Range and Mt Duppa at 3400 ft.

Controlled Airspace

It can be assumed that the pilot would have seen the cloud covering the Nelson Ranges and top of the North Island.

It is believed his intended route was to track over D’Urville Island to French Pass, keeping under the Nelson controlled airspace, then on to the head of the Queen Charlotte Sound, and from there to Wairau Valley township, avoiding the Woodbourne Control Zone and descending under controlled airspace.

It is also believed the pilot had an aversion to flying in controlled airspace and speaking to air traffic control. This may well have influenced his decisions in regard to his route.
During his training he had taken this route between Nelson and Woodbourne airspace and would have been familiar with it.

The pilot did not file a flight plan for his intended flight and there were no recorded radio communications with any Air Traffic Services during the flight.

Cloud Cover

http://wxmatters.co.nz/sites/default/files/Mtduppe3_replacement.mp4

As discussed earlier, the weather at Nelson and Blenheim was forecast for cloud cover below the level of the Bryant Range.

Two experienced pilots, both of whom had either been flying or driving through the Bryant Range area around the time of the accident, described the weather conditions as being extremely poor with a low cloud base of approximately 1200 ft and light drizzle.

The majority of the Bryant Range including Mt Duppa was obscured by cloud.

Choices

To the left was Woodbourne with a cloud base of 2000 ft, in order to follow this option the pilot would have had to fly around the edge of the Marlborough Sounds and follow the east coast of the South Island down to Ashburton. He would also have needed to speak with Woodbourne Tower to obtain a clearance through the Woodbourne Control Zone.

click to display video

Ahead, on his preferred route, the cloud was sitting below the level of the Bryant Mountain range.

click to display video

To the right was Nelson, with a cloud base of approximately 3000 ft but clear underneath, this option included the possibility of finding a way through the cloud south of Nelson. This would also have required asking Nelson Tower for a clearance through the Nelson Control Zone. The other obvious option was to turn back and land at Paraparaumu, where the weather was fine.

click to display video

EFIS

SML was fitted with an advanced EFIS (Electronic Flight Information System) and it is likely the pilot placed a lot of faith in this equipment.

However, apart from this being a very unwise decision – to enter cloud – the terrain information was flawed.

The Fateful Decision

http://wxmatters.co.nz/sites/default/files/worsening_weather.mp4

At some point near the end of the flight the pilot chose to enter cloud and follow the EFIS information. As soon as he lost sight of the ground and his primary reference, the horizon, he entrusted his survival to luck.

The Outcome

http://wxmatters.co.nz/sites/default/files/whiteout_and_accident.mp4

SML impacted Mt Duppa at approximately 1345, 9 April 2011. The pilot was killed and the aircraft destroyed.

Investigation Findings

The accident occurred in daylight, at approximately 1345 hours on 09 April 2011, approximately 15 nautical miles north-east of Nelson on the north-west slope of Mt Duppa which forms part of the Bryant Mtain Range, at an elevation of 3600 ft.

SML, was a high performance aircraft masquerading as a microlight.

It cruised at 135-140 kts, had an advanced electronic flight information system and was fitted with long-range tanks, giving it a 2000 NM range.

The accident flight was planned non-stop between North Shore and Ashburton and was expected to take approximately 4 hours.

This was a long flight in a fast aeroplane.

The CAA Accident Report states “The pilot had flown this route previously in ZK-SML with other experienced pilots, however this was the first time he had attempted the flight on his own. It is possible that he had never encountered similar weather conditions on previous flights and was therefore lacking in experience in dealing with such conditions.”

After departure from North Shore Aerodrome, there were no recorded communications from the aircraft. It is believed the pilot regularly planned his route to avoid controlled airspace, and further did not make any calls to Christchurch Information to either provide or receive information.

Because of the high level of sophistication of the EFIS (Electronic Flight Information System) onboard, it is reasonable to assume the pilot had a high level of faith in the accuracy of the information that was presented to him. The pilot probably had an over reliance on this information instead of using his basic navigation skills and applying the VFR meteorological minima for flight.

In addition there were two errors that contributed to the pilot believing he was clear of terrain when he entered cloud; we will discuss these in more detail later.

Needless to say, the decision to enter cloud and not remain VFR was the problem – not the faults in the EFIS system.

The Weather

This is the weather the pilot received from MetFlight.

The highlighted elements show cloud cover across large parts of the South Island from 2000 ft to 7500 ft.

The satellite pictures also confirm the area of this cloud cover.

ARFOR TN VALID 1700 TO 0200 UTC 1000 VRB05 3000 VRB05 5000 27005 PS10 7000 24010 PS07 10000 22015 PS03 FZL 12000FT. VIS 30KM . CLD AREAS BKN CUSC 2500 TOPS 7500. WX NIL SIG.

TAF NZNS 082143Z 0821/0912 23005KT 30KM BKN030 BECMG 0823/0901 01010KT BECMG 0908/0910 23005KT TEMPO 0908/0912 BKN006 2000FT WIND VRB05KT =

TAF NZWB 082143Z 0821/0912 27005KT 30KM FEW015 BKN020 BECMG 0823/0901 06010KT BECMG 0906/0908 32010KT TEMPO 0908/0912 BKN006 2000FT WIND 24010KT BECMG 0906/0908 32010KT =

TAF NZCH 082257Z 0900/0924 05008KT 9999 BKN025 TEMPO 0906/0910 BKN008 BECMG 0910/0912 0500 FG BKN001 BECMG 0920/0922 9999 NSW BKN012 2000FT WIND VRB05KT BECMG 0914/0916 02015KT =

The Pilot's View

From D’Urville Island this is what the pilot would have seen.

GARFOR

This is a graphical representation of the weather forecast for the route North Shore to Ashburton. In particular we have shown the weather for the last part of the flight from D’Urville Island to Christchurch.

The Options

  1. He had five options available to him when confronted with the cloud at the top of the North Island;
  2. He could continue on his current planned route, despite clear indications it was not VFR conditions.
  3. He could have descended and gone through the NS airspace and found a route over the ranges further south. This would have meant talking to ATC
  4. He could have gone via Blenheim and down the east coast of the South Island, he would probably have had to fly at 2000 ft, but still remained VFR (clear of cloud). This would have meant talking to ATC.
  5. He could have turned back and landed.
  6. He could have climbed and gone over the top of the cloud. This would have meant talking to ATC. He chose to continue with his original plan, perhaps because the conditions were fine at destination. He hit Mt Duppa (3700 ft) at 3600 ft.

EFIS Errors

SML was fitted with an EFIS system with a single display screen and a two-axis autopilot. This EFIS was capable of displaying GPS moving map, synthetic terrain and terrain proximity warnings.

The EFIS was not certificated and therefore not permitted to be used as a primary means of navigation, however, the system could be used as an aid to primary navigation, ie, as a map and compass.

During the investigation it was discovered the moving map display did not accurately display the 3717 ft spot height for Mt Duppa. The spot height was positioned at a join in the maps and the ‘3’, if not looked at carefully, could have been read as a ‘1’, making the spot height seem to be 1717 ft, not the 3717 ft it should be.

There was an additional error affecting the EFIS terrain display and warnings. An error of approximately 600 ft existed between the actual terrain height and the modelled terrain height in the terrain database. This error led to the EFIS displaying terrain indications associated with the modelled terrain of approximately 600 feet lower than the actual terrain.

Given the errors found in the EFIS system database, the pilot may have considered he was sufficiently clear of the terrain ahead, when he was not. Approaching Mt Duppa the pilot should have received a visual warning from the EFIS that he would not clear the terrain ahead, however, due to the system inaccuracies the display indicated he was clear.

All of these inaccuracies, however, would not have materially impacted the flight if the pilot had remained clear of cloud.

Taking The Gamble

This pilot placed his faith in his seemingly sophisticated avionics system, and gambled the cloud he was about to fly through had very little extent. He knew it was fine and clear at his destination and he seemed determined to get there.

No flight should be operated in a way that leaves the outcome to chance.

Swiss Cheese

http://wxmatters.co.nz/sites/default/files/swiss_cheese%20%281%29_1_0.mp4

No accident causes are isolated to one factor; there are always a number of factors that align to cause an accident.

Reason’s Swiss Cheese model helps us to visualise the errors that occurred in order for this aircraft to crash into the side of Mt Duppa.

Conclusion

http://wxmatters.co.nz/sites/default/files/Jim_summary.ogv

Weather-related decision making is continuing to contribute to accidents and incidents throughout New Zealand.

We, as a pilot community, need to continue to improve our knowledge of weather and how it will affect our flights, and to continually improve our decision-making skills.
Let’s make this kind of accident a thing of the past.

http://wxmatters.co.nz/sites/default/files/carlton.mp4

Weather-related decision making is continuing to contribute to accidents and incidents throughout New Zealand.

We, as a pilot community, need to continue to improve our knowledge of weather and how it will affect our flights, and to continually improve our decision-making skills.
Let’s make this kind of accident a thing of the past.

Invercargill

Above mean sea level

TCu

Towering Cumulus

agl

above ground level

Cb

Cumulonimbus

Flight Information Service communications

ATS

Air Traffic Service

Royal New Zealand Air Force

in vicinity of aerodrome Thunderstorm

ATC

Air Traffic Control

VC

in vicinity of aerodrome

Probabilityxx%

TIL

Until

FM

From

Becoming

Temporarily

Routine air report from aircraft in flight

FIR

Flight Information Region

Internet Flight Information Service

VFR

Visual flight rules

Automatic Terminal Information Service

BWR

Basic weather report

New Zealand Flight Information Region

Aerodrome special routine meteorological report

Automatic aerodrome routine meteorological report

Aerodrome routine meteorological report

TAF

Aerodrome forecast

Area forecast

Significant meteorological information