PH-TEN
1948-OCT-20 · Prestwick, Scotland

KLM — Flight PH-TEN

A KLM Lockheed Constellation, named Nijmegen, crashed during a visual approach to Runway 26 at Prestwick Airport in deteriorating weather. The aircraft struck high-tension electricity pylons while flying downwind at a low altitude, caught fire, and impacted high ground shortly after. All 40 occupants perished, including the renowned KLM chief pilot Koene Dirk Parmentier. The investigation highlighted a combination of inaccurate KLM approach charts, which omitted high terrain and obstacles, and the failure of ground authorities to communicate rapidly worsening weather conditions to the crew.

Aircraft
Lockheed L-049-46-25 Constellation
Registration
PH-TEN
Phase
Approach
Cause
Controlled Flight Into Terrain (CFIT)
Souls on Board
40
Fatalities
40
Origin → Dest
Amsterdam-Schiphol International Airport (AMS) → Glasgow-Prestwick Airport (PIK)
Report
Final

Investigation Summary

The flight was delayed at Schiphol to load additional cargo for Iceland, a delay that proved fatal as it caused the crew to miss critical weather broadcasts from Prestwick. Captain Parmentier, a highly experienced aviator, was operating with charts that were essentially copies of flawed wartime USAF maps. These charts indicated a spot height of 45 feet in an area where 132,000-volt electricity pylons actually stood. Furthermore, the charts failed to mark terrain exceeding 400 feet near the airfield. During the approach, Parmentier was vectored for a Ground Controlled Approach (GCA) to Runway 32 but opted for a visual circuit to Runway 26 to avoid a crosswind. While flying the downwind leg at approximately 450 feet, the aircraft entered a low cloud base and struck national grid power lines approximately 3 miles (4.8 km) inland. Although the crew attempted to maintain control and turn back toward the runway, the burning aircraft crashed into a hill 5 miles (8 km) east-north-east of the airport.

Final Conclusions

The court of enquiry determined the probable cause was the extension of the flight on the downwind leg at a low altitude, likely due to the pilot losing visual contact in unexpected fog. Contributing factors included the failure of ground control to inform the crew that weather had dropped below landing limits, and the use of KLM approach charts that contained gross errors regarding terrain and obstacles. The enquiry expressed astonishment that KLM had relied on inaccurate foreign-sourced maps when high-quality Ordnance Survey maps were available.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Airframe Hours
0
Engines
Wright R-3350 Duplex-Cyclone

Systems & Failure Modes

i

Approach Charts

The KLM-issued charts were inaccurate, failing to show terrain heights above 250 feet and omitting major obstacles like power lines.

i

Ground Controlled Approach (GCA)

The radar system available only for Runway 32; the pilot chose a visual approach to Runway 26 which lacked radar guidance.

Interesting Facts

  • 01The aircraft was named 'Nijmegen' and was piloted by KLM's chief pilot, Koene Dirk Parmentier.
  • 02The KLM approach charts used by the crew were based on faulty wartime USAF maps and omitted 600-foot wireless masts and 400-foot hills.
  • 03Two SAS airliners had already diverted from Prestwick that evening due to the weather, but the KLM crew was unaware of this.
  • 04The aircraft struck a 132,000-volt national grid line carrying power to South Scotland.
  • 05While six people were initially found alive by rescuers at the crash site, all 40 occupants ultimately perished, with the final survivors succumbing to their injuries within 24 hours.

Safety Actions & Advisories

Chart Verification

The court of enquiry recommended that airlines use accurate national mapping, such as the UK's Ordnance Survey maps, rather than relying on unverified or outdated foreign-sourced charts that may contain gross errors regarding terrain and obstacles.

Location

Prestwick, Scotland · 55.5084, -4.5044

Case File History

  1. New evidenceUpdated investigation summary, event timeline and findings.
  2. New evidenceUpdated investigation summary, findings and safety actions.

Related Cases

Case ID · klm-nijmegen-1948Last updated · Filed

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