[Valid Atom 1.0]

domingo, 25 de abril de 2010

Iroquois' flightpath mystifies helicopter pilots

VICTIMS: Flight Lieutenant Hayden Peter Madsen, pilot, 33; Fying Officer Daniel Stephen Gregory, pilot, 28, and Corporal Benjamin Andrew Carson, helicopter crewman, 25.

The base for the emergency services near Pukerua Bay after a military helicopter crash.


The Air Force takes a closer look at the crash scene in between patches of heavy cloud






PROUD MOMENT: Hayden Madsen is presented with his wings by then Prime Minister Helen Clark at Ohakea Air Force Base in this 2005 photo. Mr Madsen was one of the three people killed in a Iroquois chopper crash near Wellington on Anzac Day.



Anzac tragedy for air force

video

By KIRAN CHUG and AMANDA FISHER - The Dominion Post
Last updated 05:00 26/04/2010

<span class=The flightpath of the Iroquois helicopter that crashed into a hillside near Pukerua Bay, north of Wellington.">

The flightpath of the Iroquois helicopter that crashed into a hillside near Pukerua Bay, north of Wellington.


Experienced helicopter pilots are mystified as to why an Iroquois was flying through cloud over land when it crashed, instead of further off the coast where conditions would have been clearer.

They say Iroquois are among the most reliable aircraft in the world and well-equipped to fly in foggy and cloudy conditions, and are at a loss to explain how yesterday's fatal crash happened.

While investigations into the crash are under way, pilots familiar with the route say they cannot understand why the aircraft had not been heading away from land and off the coast, where conditions would have been clearer.

MetService said that, about the time of the crash at 5.50am, clouds were down to 122 metres at Paraparaumu, its weather station nearest to Pukerua Bay.

However, Alan Beck, of Beck Helicopters, said fog often covered the farm hill where the helicopter came down, and conditions there would have been worse.

Mr Beck flew an Iroquois over that farm to spread fertiliser six months ago. Although he believed Iroquois were the "safest helicopters ever built", he said he would not have flown in that area in yesterday morning's conditions.

However, he said the air force Iroquois were better equipped that the civilian aircraft. "I would be very very surprised if it was a mechanical fault that caused it because they are so reliable."

Mr Beck said the investigation would look at why the three aircraft separated, and he questioned whether one had changed course to Paraparaumu because of poor conditions.

Helicopter Association chairman Toby Clark said Iroquois were capable of flying in adverse conditions. "They have got a huge track record of being rated as the number one military workhorse helicopter in the world."

In yesterday's conditions, he would have expected pilots to fly along the coastline, and at low altitudes if necessary.

Air force Iroquois could be flown "visually", with a pilot relying on viewing the conditions and landscape to choose a flight path, or in "instrument" mode.

In this mode, the pilot relied on instruments and equipment within the helicopter for direction and was able to fly through cloud.

Mr Clark used to pilot Wellington's rescue helicopter and was familiar with flying along the Kapiti Coast. "We would fly the coastline because anything off the coast is no higher than the sea and you know you are going to be clear of the land as the norm."

Helipro chief executive Rick Lucas said the helicopters had been following a route commonly taken by the air force.

There was no prescribed route for the aircraft, as the flight path was up to the discretion of the pilot.

Conditions at that time would have made it "challenging" to fly through Pukerua Bay, but though visibility was reasonably poor, it would have been clearer further off the coast, he said.

He would have expected the three helicopters to be flying in formation over the coastal route because of the conditions.

Mr Lucas lives near the crash site, and was woken by aerial activity about 7am.

"I thought, 'It's the Iroquois going to the dawn parade [but] it sort of continued, which may have been other helicopters looking for the downed aircraft.

"It's one of those things. It's not good, you hope for the best but you expect the worst. It was obviously not going to be a good result the longer it [went] on."

He said an "accumulation of factors" had probably led to the accident.

LONG SERVICE HISTORY

The Iroquois helicopter involved in yesterday's crash was one of 14 operated by the Royal New Zealand Air Force.

The single-engine, 17 metre-long Iroquois helicopters have a cruising speed of 195kmh.

The air force took its first delivery of five Iroquois helicopters in 1966.

The only other fatal crash involving a military Iroquois helicopter was on April 27, 1972. Three people were killed when the helicopter crashed into sandhills near the Kaipara Harbour.

Another Iroquois was written off in in March 1995 when engine failure forced it to land short of the Waiouru helipad and overturn in the Ngamatea swamp.

The air force has been considering upgrading its Iroquois since the 1980s because of airframe fatigue problems with parts, including the rotor blades. The helicopters also carry equipment which will become obsolescent and have limited performance in tropical conditions.

After the use of Iroquois in East Timor between 1999 and 2002, the decision was made to replace the fleet.

The air force is in the process of replacing the helicopters with eight NH90 utility choppers. The French-made aircraft were due to arrive early this year and would be fully commissioned by 2013 as part of a $771 million deal.



๑۩۞۩๑๑۩۞۩๑๑۩۞۩๑๑۩۞۩๑๑۩۞۩๑


LAST

Sphere: Related Content
26/10/2008 free counters