| Username |
Post |
| marich |
Posted
on 25-May-04 06:45 AM
I guess you all have read about it by now. I just did on Nepalnews.com
I can relate to somewhat similar situation.
I was back home and was flying to Lukla on a HMG project that ultimately took us to Kalapathar. We had flown from KTM to Lukla on our Royal Jhandabahak, a Twin-otter, and instead of landing at Lukla, had to return and land in Kathmandu. The plane did arrive Llukla airport and hovered over it three times , turned back and landed in KTM.The only explaination was was not safe to land in Lukla at that time.
On our next attempt , within two days, the plane dropped straigt for 1400 ft right over the pass and as we were ping -ponged inside. Many of us had bruises ( Tutulko) on our heads when we bumped the roof of the plane. Nothing restrained us from reaching the roof, blame it on too much excitement to look out the window. So the plane took immediate turn and again landed back in KTM airport. Later the Pilot explained that he was given permission to gain altitude to avoid one turbulence that we were heading directly into. But it turned out to be swirling at above us, and to save the plane, us and himself, he to drop the plane suddenly. He said that was normal as it happens all the time. He also mentioned these turbulences are always swirling around right as you are over th pass. I had no idea what he meant as i was holding my head all the way to home.
Within three days was our third attempt on which the Lukla airport did come to sight and we thought we had made it then. But no, not yet.The plane again returned back to ktm for the reason being poor visibility ( unreasonable, as i could see the airport) and the safety issue, which was again not explained what it exactly was.
Then we had to charter a Puma from the army and we landed straight at Namche.After 3 days of walk we were at Dingboche and next two days we spent at Kalpathar that made me forget all the scary experiences I had.
After those incidents I knew something like this was gonna happen some days in the future, but hard to imagine it is happning now, almost after 14 yrs of my expereince, when the technology supoosedly is advanced than back then, when , it was rumored, that the meterologist at the Lukla airport, Measured the wind speed and direction by hanging a string( Dhago) by their hand and standing in the middle of the Gravelled, and slanted at a 65 degree angle Runway. Those of you who have been to Lukla know what I am talking about.
May god give the families of the victims to cope with this situation.
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| marich |
Posted
on 25-May-04 06:50 AM
The pass I am reffering above is the LamaJura pass which you have to cross on foot if you were to walk from Jiri to Lukla, someone told me while in the flight. I heard that part of tekking is really tough. I am not sure as I never trekked from Jiri.
But had similar experience when trekking from Jumla to Dolpa, a pass called Maurie Lakh was pretty tough.
Just thought of sharing.
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| Arnico |
Posted
on 25-May-04 09:17 AM
Does anyone know the registration number of the aircraft that crashed?
My wife and I flew to Lukla on Yeti in November, and we hit REALLY bad turbulence just after crossing Lamjura pass.
I did note that the aircraft had GPS systems in the cockpit, but with only very few waypoints marked (Jiri, Lamjura Pass, Lukla airport). On the flight back from Lukla we were in dense clouds, from Lukla almost all the way to Lamjura pass, with me (sitting right behind the cockpit) nervously watching the track on the GPS screen with far too few points indicating where we were.
The impression I get is that during a lot of times Lukla and Kathmandu airports may have decent weather, but crossing the Lamjura pass may be dangerous due to turbulence or lack of visibility.
Two questions to think about:
Instead of bearing the cost of losing people and aircraft (and in the past losing helicopters) around Lamjura, wouldn't it make more sense to:
(1) invest in much better GPS mapping software that tells pilots EXACTLY where they are in relation to sourrounding mountains.
and/or
(2) Burning a bit more fuel, avoiding Lamjura Pass and its turbulence alltogether, and following the Dudhkoshi further south, going around the south side of Pike Mountain, or even through northern Okhaldhunga?
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| Badmash |
Posted
on 25-May-04 10:00 AM
Marich Ji,
Interesting account. Obviously things haven't changed much in the last 14 years. And there is only so much you can do about the topography.
Arnico,
If I am correct, none of the domestic flights in Nepal are instrument flights. With exception of TIA, I doubt any of the other airports have equipment to guide instrument flights into landing. While GPS can help tremendously to determine your position in relation to earth, but it won't do much to warn you about the obstructions that you are headed towards. With visual flights, you just avoid flying into clouds or anything that will impair your visibility. If you do find yourself in clouds, you just climb to avoid any collision. But climbing in a thin air with a propeller powerded aircraft is a very gradual process as you know.
With dagerous terraiin like Nepal, you just have to hope the weather will stay clear, or you won't fly. It will likely be a while before instrument guided flights will be flown into these tiny landing strips.
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| Arnico |
Posted
on 25-May-04 10:19 AM
Badmash,
I was not referring to instrument landing. I was referring to navigation using a GPS system that gives exact location with reference to the ground.
It seems to me that a system can be built for a less than US$1000 that would do the job. Basically one would need the following:
(1) A good colorscreen PDA (~$300-400) connected to a GPS that displays GPS location and GPS tracks on scanned images of high quality topo maps.
(2) Oziexplorer software (available online for $ 85) that allows scanned maps to be used on the GPS.
http://www.oziexplorer.com
(3) A commercial GPS with a built-in barometer and an external antenna (to be mounted at the windshield or outside the aircraft. (~$400-500)
(4) A GPS to PDA cable ($25).
Wouldn't this be something worthwhile to test out???
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| Binay |
Posted
on 25-May-04 11:19 AM
Arnico, let me make a very quick comment to what you have suggested here. Yes, GPS and INS can immensely help air navigation systems; however, the level of accuracy and precision required by the standard aviation systems can only be achieved by differential GPS and other industry/miliatary standard GPS/GLONASS/GALILEO systems. We are talking about milimeter level accuracy. The examples you mentioned above or non-differential GPS (e.g., handheld GPS, GPS joined on a PDA) have about 10-100-m error, which means the error margin is too high for any aviation applications. And, while the use of GPS certainly helps in remote areas like Nepal, the users ought to be familiar with all the odds (e.g., multipath created by rugged terrains, differences in datum, projection, and coordinate systems used in Nepal, which BTW can be very cumbersome).
I do agree with you that it can be very exciting to do "real-time" location-based navigation with the help of a PDA and a handheld GPS combined. I have tried it once in Nepal to do "groud-truthing" of satellite images by collecting training samples, but it turned out to be a lot more complex to achieve standard accuracy level.
Going back to the main point of this thread, I also had some scary moments ridding on twin-otters and German Dornier (?) to Jumla and Tumglingtar. I was too shy share my experiences with local people who were used such incidents. My heartfelt condolence to the families.
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| Badmash |
Posted
on 25-May-04 12:34 PM
Arnico Jyu,
I like the idea and it certainly wouldn't hurt to try. But like Binay said, the level of accuracy needed in such rigid terrain is probably more than what GPS can offer.
Having said that, despite all apllicable instruments installed, it stilll comes down to a person's ability to read those instruments and guide the aircraft accordingly. I have always been suspecious of improperly trained or inexperienced pilots being dispatched to one of the world's most difficult terrain.
Flying Kathmandu to Lukla route is certainly nothing like flying in a clear day in the skys of Oklahoma under visual flight rules (VFR). Mere 40 hours of flying time and good health certificate gives you the private pilot license in the US. Of course, it won't allow you to fly any commercial aircraft. You have to put at least 1500 hours and demonstrate proficiency in instrument flight rules (IFR) and and multi engine aircraft before you get to carry passengers. I wonder what the requirements in Nepal are. Does anyone know?
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| Biswo |
Posted
on 25-May-04 06:12 PM
It is a sad news.I remember meeting some old people in Surke who told me their son/daughter worked in Yeti Airlines as pilot/airhostess. That pass was very scary also.
Yeti Airlines is a very popular airlines in that part. I have heard the owner is a Sherpa from Khumbu area, don't know the truth though.It is so sad to hear of the accident. May the soul of the dead ones rest in peace.
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| Binay |
Posted
on 25-May-04 08:19 PM
Badmash, actually that is NOT exactly what I said. I was only pointing out the downside of non-differential....repeat NON-DIFFERENTIAL GPS system that Arnico used as an example. As I said earlier, there is a huge difference in terms of accuracy between "differential" GPS (i.e., an industry standard system primarily used by miliatary, aviation and other transportation industries, and surveyers) and "non-differential" GPS (e.g., handheld GPS that is available for general public and the one Arnico was referring to). I was only trying to point out that the use of non-differential GPS system for aviation industry in such rugged terrains like Nepal should be taken cautiously.
Differential GPS, on the other hand, has been widely used by the US Army in rugged terrains like Afganishtan and their accuracy level has been quite good. This differential GPS system is now so much the part of the US Army that they already have a multi-billion dollors plan for GPS-II in the near future, pertty much parallel to upcoming European Galileo system. The access to such technologies from the countries like ours is a kinda dream, but I wanna be optimistic like Arnico who always brings fresh, positive perspectives on Nepal and Nepali--something I admire a lot.
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| Arnico |
Posted
on 25-May-04 09:14 PM
Forgot to mention earlier: my condolences to the family members of the crew on board that flight.
Binay, thanks for the details about GPS. I am still very much a novice in using just commercially available GPS instruments.
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