Crash of a De Havilland DHC-6 Twin Otter 300 in Lukla: 3 killed

Date & Time: May 25, 2004 at 1356 LT
Operator:
Registration:
9N-AFD
Flight Type:
Survivors:
No
Site:
Schedule:
Kathmandu - Lukla
MSN:
651
YOM:
1979
Flight number:
YET117
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
While descending to Lukla Airport from the south following a cargo flight from Kathmandu, the crew encountered poor visibility due to clouds when, at an altitude of 11,600 feet, the aircraft struck the slope of a mountain located near the Lamjura Pass, in the Solukhumbu district. The wreckage was found west of the airport and all three crew members were killed.
Probable cause:
Controlled flight into terrain. The following factors were identified:
- Hazardous behaviour and attitudes of the captain such as overconfidence,
- The crew failed to comply with the approach routes, following a direct track,
- The crew failed to follow SOP's,
- The operator's policy for flying in adverse weather were incomplete and not up to date,
- Lack of communication by the operator,
- The operator was unable to perform internal investigations and execute corrective actions when required.

Crash of a De Havilland DHC-6 Twin Otter 300 in Simara: 10 killed

Date & Time: Dec 25, 1999 at 1502 LT
Operator:
Registration:
9N-AFL
Flight Phase:
Survivors:
No
Site:
Schedule:
Simara - Kathmandu
MSN:
796
YOM:
1982
Location:
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
7
Pax fatalities:
Other fatalities:
Total fatalities:
10
Circumstances:
The twin engine aircraft departed Simara Airport at 1457LT on a schedule flight to Kathmandu with 10 people on board. Three minutes after takeoff, while climbing in marginal weather conditions, the aircraft struck the slope of Mt Burja Lek located few km from the airport. The aircraft disintegrated on impact and all 10 occupants were killed. At the time of the accident, the visibility was estimated to be 5 km with low ceiling.
Probable cause:
Controlled flight into terrain after the crew failed to follow the correct route after takeoff and continued at an insufficient altitude until the aircraft collided with terrain.

Crash of an Avro 748-501-2B in Kathmandu: 15 killed

Date & Time: Sep 5, 1999 at 1030 LT
Type of aircraft:
Operator:
Registration:
9N-AEG
Survivors:
No
Site:
Schedule:
Pokhara - Kathmandu
MSN:
1806
YOM:
1988
Flight number:
3Z104
Country:
Region:
Crew on board:
5
Crew fatalities:
Pax on board:
10
Pax fatalities:
Other fatalities:
Total fatalities:
15
Circumstances:
On approach to Kathmandu-Tribhuvan Airport under VFR mode, the crew encountered limited visibility due to a low cloud layer. On final, at an altitude of about 6,000 feet, the aircraft collided with a radio antenna (100 feet high) located on the top of a hill and owned by the Nepalese National Broadcasting Company. The aircraft went out of control and crashed seven km short of runway 02. All 15 occupants.
Probable cause:
Collision with obstacle on a VFR approach in limited visibility.

Crash of a Boeing 727-243F in Kathmandu: 5 killed

Date & Time: Jul 7, 1999 at 1951 LT
Type of aircraft:
Operator:
Registration:
VT-LCI
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Katmandu – New Delhi – Sharjah
MSN:
22168
YOM:
1981
Flight number:
LCI8533
Country:
Region:
Crew on board:
5
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
5
Aircraft flight hours:
43000
Aircraft flight cycles:
25000
Circumstances:
The aircraft departed Kathmandu-Tribhuvan Airport on a cargo flight to Sharjah with an intermediate stop in New Delhi, carrying five crew members and a load of 21 tons of woolen carpets. After takeoff from runway 20, the crew continued to climb but failed to realize his altitude was insufficient. The aircraft struck the slope of Mt Champadevi located 11 km southwest of the airport and disintegrated on impact. All five crew members were killed.
Probable cause:
The accident occurred as the crew after take off did not adhere to the published Standard Instrument Departure (SID) procedure for runway 20 at Kathmandu, Nepal.
The following contributory factors were identified:
- Incomplete departure briefing given by P1 while other cockpit activities were in progress,
- The unexpected airspeed decay to V 2 -3 during initial right climbing turn South of the VOR which occurred while P2 was busy with ATC,
- The improper power and climb profile used by P1 after rolling the aircraft out on a southwest heading following the initial airspeed loss,
- The inadequate intra cockpit crew coordination and communication as the aircraft proceeded to and across the KTM VOR 4 DME arc before recommencing a shallow right turn, and
- The incorrect and slow response to the initial and subsequent GPWS activation prior to the collision with the terrain.

Crash of a Pilatus PC-6/B2-H4 Turbo Porter in Namche Bazar: 1 killed

Date & Time: Nov 19, 1998 at 1538 LT
Operator:
Registration:
9N-ABK
Flight Type:
Survivors:
No
Site:
Schedule:
Kathmandu - Namche Bazar
MSN:
755
YOM:
1975
Country:
Region:
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Aircraft flight hours:
5762
Circumstances:
The pilot, sole on board, departed Kathmandu-Tribhuvan Airport on a positioning flight to Namche Bazar to pick up passengers. During the pre-flight briefing, he was informed about the good weather conditions along the route and at destination. But en route, these conditions deteriorated and upon arrival, clouds were present up to 3,600 metres. He made several circuits expecting weather improvement. Few minutes later, he saw a hole in the clouds and initiated a descent when the aircraft struck the slope of Mt Kongri Himal located 3 km north of the airfield. The aircraft was destroyed and the pilot was killed.
Probable cause:
Controlled flight into terrain.

Crash of an Avro 748-106-1A in Pokhara

Date & Time: Nov 6, 1997
Type of aircraft:
Operator:
Registration:
9N-ACM
Survivors:
Yes
Schedule:
Kathmandu - Pokhara
MSN:
1549
YOM:
1963
Location:
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
44
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
After landing at Pokhara Airport, the hydraulic system failed. The crew lost control of the airplane that veered off runway to the right and collided with a parked Nepal Airways Avro 748 registered 9N-ACW. All 48 occupants evacuated safely while the aircraft was damaged beyond repair.

Crash of an Avro 748-352-2B in Meghauli

Date & Time: Apr 25, 1996 at 1158 LT
Type of aircraft:
Operator:
Registration:
9N-ABR
Survivors:
Yes
Schedule:
Kathmandu - Meghauli
MSN:
1771
YOM:
1979
Flight number:
RA155
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
27
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
Following an uneventful flight from Kathmandu, the crew started the descent to Meghauli Airfield. On final, the aircraft was too high and landed too far down the runway, about 1,148 feet past the runway threshold (Meghauli Airstrip is 3,500 feet). Unable to stop on a wet grassy runway, the aircraft overran and came to rest in a ravine. All 31 occupants escaped uninjured while the aircraft was damaged beyond repair.
Probable cause:
Wrong approach configuration on part of the crew who landed the aircraft too far down the runway, reducing the landing distance available. Also, it was reported that the braking action was poor as the grassy runway was wet.

Crash of a De Havilland DHC-6 Twin Otter 300 in Kathmandu: 2 killed

Date & Time: Jan 17, 1995 at 1359 LT
Operator:
Registration:
9N-ABI
Flight Phase:
Survivors:
Yes
Schedule:
Kathmandu - Rumjatar
MSN:
392
YOM:
1973
Flight number:
RA133
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
21
Pax fatalities:
Other fatalities:
Total fatalities:
2
Circumstances:
During the takeoff roll on runway 20 at Kathmandu-Tribhuvan Airport, the aircraft failed to get airborne, overran, went through a fence and came to rest in a field. A passenger and a pilot were killed while all other occupants were rescued.
Probable cause:
It was determined that the crew was composed by two captains. For unknown reasons, the pilot-in-command decided to abort the takeoff procedure but the crew failed to coordinate this decision. At the time of the accident, the total weight of the aircraft was 60 kilos above MTOW.

Crash of a Dornier DO228-101 in Bharatpur: 19 killed

Date & Time: Jul 31, 1993
Type of aircraft:
Operator:
Registration:
9N-ACL
Survivors:
No
Site:
Schedule:
Kathmandu - Bharatpur
MSN:
7029
YOM:
1984
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
16
Pax fatalities:
Other fatalities:
Total fatalities:
19
Circumstances:
While descending to Bharatpur Airport, the crew encountered poor weather conditions. Too low, the aircraft struck the slope of a rocky peak located about 6,5 km short of runway 15 threshold. The aircraft was destroyed and all 19 occupants were killed.

Crash of an Airbus A300B4-203 in Kathmandu: 167 killed

Date & Time: Sep 28, 1992 at 1430 LT
Type of aircraft:
Operator:
Registration:
AP-BCP
Survivors:
No
Site:
Schedule:
Karachi - Kathmandu
MSN:
025
YOM:
1976
Flight number:
PK268
Country:
Region:
Crew on board:
19
Crew fatalities:
Pax on board:
148
Pax fatalities:
Other fatalities:
Total fatalities:
167
Captain / Total flying hours:
13186
Captain / Total hours on type:
6260.00
Copilot / Total flying hours:
5849
Copilot / Total hours on type:
1469
Aircraft flight hours:
39045
Aircraft flight cycles:
19172
Circumstances:
The ill-fated aircraft departed Karachi Airport Pakistan, at 0613 hours UTC on 28 September 1992 as Pakistan International Airlines Flight Number PK 268, a non-stop service to Kathmandu, Nepal. The accident occurred at 0845 UTC (1430 hours local time) when the aircraft struck a mountain during an instrument approach to Kathmandu’s Tribhuvan International Airport. The impact site was at an altitude of 7280 feet above sea level (2890 feet above airport level), 9.16 nautical miles from the VOR/DME beacon and directly beneath the instrument approach track from the VOR/DME beacon (9.76 nm from and 2970 ft above the threshold of Runway 02 which is 77 feet below the airport datum). The flight through Pakistani and Indian airspace appears to have proceeded normally. At 0825 hrs UTC (1410 hrs local time) two-way contact between Pakistan 268 and Kathmandu Area Control West was established on VHF radio and the aircraft was procedurally cleared towards Kathmandu in accordance with its flight plan. After obtaining the Kathmandu weather and airfield details, the aircraft was given traffic information and instructed to report overhead the SIM (Simara) non-directional beacon (214°R VOR/39 nm from Kathmandu’s KTM VOR/DME) at or above FL150 (flight level on standard altimeter) as cleared by the Calcutta Area Control Centre. At 08:37 hrs the copilot reported that the aircraft was approaching the SIM beacon at FL 150, whereupon procedural clearance was given to continue to position SIERRA (202°R/10 nm from the KTM beacon) and to descend to 11,500 feet altitude. No approach delay was forecast by the area controller and the co-pilot correctly read back both the clearance and the instruction to report at 25 DME. At 08:40:14 hrs, he reported that the aircraft was approaching 25 DME whereupon the crew were instructed to maintain 11,500 feet and change frequency to Kathmandu Tower. Two-way radio contact with the Tower was established a few seconds later and the crew reported that they were in the process of intercepting the final approach track of 022M (Magnetic) of Radial 202 KTM VOR ) They were instructed to expect a Sierra approach and to report at 16 DME. At 08:42:51 hrs the first officer reported “One six due at eleven thousand five hundred”. The tower controller responded by clearing the aircraft for the Sierra approach and instructing the crew to report at 10 DME. At 08:44:27 the first officer reported 10 DME and three seconds later he was asked, “Report your level”. He replied, “We crossed out of eight thousand five hun,’ two hundred now”. The controller replied with the instruction “Roger clear for final. Report four DME Runway zero two”. The copilot responded to this instruction in a normal, calm and unhurried tone of voice; his reply was the last transmission heard from the aircraft, thirty-two seconds after the copilot reported 10 DME the aircraft crashed into steep, cloud-covered mountainside at 7,280 feet amsl and 9.16 nm on radial 202 of KTM VOR. All 167 occupants were killed.
Probable cause:
The balance of evidence suggests that the primary cause of the accident was that one or both pilots consistently failed to follow the approach procedure and inadvertently adopted a profile which, at each DME fix, was one altitude step ahead and below the correct procedure. Why and how that happened could not be determined with certainty because there was no record of the crew's conversation on the flight deck. Contributory causal factors were thought to be the inevitable complexity of the approach and the associated approach chart.
The following findings were reported:
- The flight deck crew were properly licensed and medically fit,
- The aircraft had been properly maintained and was fit for the flight and the essential aircraft systems were operating normally during the approach,
- The SIERRA approach to Kathmandu is a demanding approach in any wide-bodied aircraft,
- Unlawful interference and extreme weather were not causal factors,
- The crash site was enveloped in cloud at the time of the accident,
- There was no ATC clearance error,
- The VOR DME beacons used for the approach were operating satisfactorily and there was no evidence of failure or malfunction within the aircraft’s DME equipment,
- The aircraft acquired and maintained the correct final approach track but began descent too early and then continued to descend in accordance with an altitude profile which was consistent with being 'one step ahead' and below the correct profile,
- At 16 DME the co-pilot mis-reported the aircraft’s altitude by 1,000 feet,
- The commander did not adhere to the airline’s recommended technique for the final part of the approach which commenced at 10 DME,
- The 10 DME position report requested by the Tower controller was made at an altitude below the minimum safe altitude for that portion of the approach,
- The altitude profile on the Jeppesen approach chart which should have been used by the pilots was technically correct. However, the profile illustrated could not be flown in the A300 at V app, in common with any other wide-bodied jet of similar size and the minimum altitude at some DME fixes was not directly associated with the fix,
- The aircraft did not have control column mounted chartboards,
- As described in the report, there is scope for improving the SIERRA approach procedure and its associated charts,
- Kathmandu was not a frequent destination for PIA’S A300 crews and neither pilot had operated that within the previous two months,
- PIA’s training of air crews, briefing material and self-briefing facilities for the SIERRA approach to Kathmandu leave room for improvement,
- PIA’s route checking and flight operations inspection procedures were ineffective,
- The accident was inevitable 15 seconds before impact,
- The Tower controller requested an altitude report immediately after the co-pilot reported at 10 DME. His failure to challenge the low altitude reported at 10 DME was a missed opportunity to prevent the accident but, even if he had done so, it is doubtful whether the accident could have been averted,
- Some air controllers at Kathmandu had a low-self-esteem and was reluctant to intervene in piloting matters such as terrain separation,
- The GPWS was probably serviceable but failed to warn the crew of impending flight towards high ground because of the combination of elderly equipment and rugged terrain,
- Advice within the aircraft manufacturer’s operating manuals regarding pilot reaction to a GPWS warning was incomplete,
- The MEL was being breached in that PIA wen not supplying their CAA with the required carry-forward defect summaries for analysis, neither was the CAA requesting them.