Saturday, August 15, 2009
High Altitude Landing
Once I was asked to attend a meeting with the Sabah state officials. It was about the construction of a rest house at Gunung Kinabalu. The Army was represented by Maj Jamil of the Engineering Squadron. The proposed site was at about 10,000 feet, I think. The state wanted the nuri to airlift the building materials. The Army would provide the manpower.
Mawilud 11 (Markas Wilayah Udara), located at Kuching, Sarawak, directed me to do high altitude flying over Labuan in anticipation of performing this task. It arranged with C130 Hercules squadron to provide me with oxygen masks and cylinders. You see, nuri is not a pressurised aircraft and as a safety measure, we have to use oxygen masks when we fly 10,000 feet and above in case we experience hypoxia. No problem, I flew for 2 hours 45 minutes over the island. In fact, I didn’t use the equipment at all.
For planning purpose, the Park HQ (PHQ) at 5,000 ft, was proposed to be the pick-up and refuelling point. The designated landing point (LP) was about 10,000 ft. Before that, let me enrich your knowledge on the characteristics of the nuri. The rules of thumb are as follows:
- Weight (empty) - 12,500 lbs.
- Max operating wt – 19,500 lbs at sea level, including fuel.
- 400 lbs weight reduction for every 1,000 feet.
- Airspeed – 110 knots at 3,000 feet.
- 6 knots speed reduction for every 1,000 feet.
- Fuel consumption – 1,000 lbs per hour.
- Reserve fuel – 600 lbs for both tanks (300 lbs/tank).
The calculation for the maximum weight for landing at LP.
- Max operating wt @ sea level – 19,500 lbs
- Max operating wt @ LP - 15,500 lbs (19,500 lbs - 4,000 lbs)
- Less wt of empty aircraft - 12,500 lbs
- Less fuel, including reserve - 2,000 lbs
- Payload available - 1,000 lbs
I could not remember the estimated flight time from the PHQ to the LP and vice versa. I think it was about 30 min for the round trip. But it was not as simple as that; must consider loading, unloading, diversion in case of bad weather. The nearest landing area in case of bad weather would be Kundasang and if not accesible, then I would fly either to Kota Kinabalu or Ranau. One thing for sure, I knew the unpredictable weather there.
Based on the calculation, I could only take a maximum of 1,000 lbs of construction materials for every sortie. I had to refuel after every flight back to PHQ. I didn’t know what the total weight of the building materials would be. And the airspeed at that height was about 70 knots. I’m sure most nuri pilots would concur with me if I said that nuri's control is sloppy with height......just like driving a 3-ton army truck without power steering.
And now, come the day for the trial flight. Airborne Labuan for Gunung Kinabalu with the estimated weight of 15,500 lbs on landing. I planned to refuel at Kota Kinabalu airport. During the recce, there was no way of determining the wind direction – only solid rock. I saw a fuselage of a crashed Bell helicopter abandoned there. To me, the best approach was flying towards the mountain.
On coming to a hover, the nuri yawed clockwise (to the right). I fully applied left pedal but was still unable to stop the yaw. The cross wind from the left was too strong. The only option available was to dive the chasm and flew off. Well, with 3,000 hours on type, this was one scary experince that will be forever in my mind. I’m an old but not a bold pilot – and that’s how you’re able to read this article!
My recommendation to Mawilud 11 ? NOT FEASIBLE. The Panglima never questioned my decision. I was told that Sabah Air got the contract to fly the materials.
Nuri pilots, I tried to be as accurate as possible to the extent of calling 5 Sqn about nuri's data. If you observe inaccurate data, please accept my humble apologies. You must bear in mind that this episode took place in 1984....25 years ago!
3,000-hour reception at No 5 Sqn dispersal area upon landing from Terumbu Layang-Layang on 30 January, 1984.
Comments are most welcome.....