New safety measures are to be introduced at Dundee Airport after two people died in a small plane crash.
Andrew Thompson, 37, and John MacKinnon, 53, died in May 2015 when the Beechcraft Baron 95-B55 aircraft crashed near the village of Abernyte in Perthshire.
There was low cloud and heavy rain in the area at the time - described as instrument meteorological conditions (IMC) - meaning the pilot had to fly primarily by reference to instruments.
An Air Accidents Investigation Branch (AAIB ) report concluded a mix-up of distances between the onboard GPS system and distance measuring equipment (DME) from the runway caused the pilot to start his descent too early.
Investigators said: "The aircraft collided with high ground 6.7 nm (nautical miles) to the west of Dundee Airport whilst conducting an instrument approach to runway 09 in IMC.
"Evidence indicates that the pilot probably mistook the distances on his GPS, which were from the NDB (non directional radio beacon), as DME distances from the threshold of runway 09 and therefore commenced his descent too early.
"Anecdotal evidence suggests that mistaking GPS distance from the 'DND' NDB with DME distance is a common error made by pilots. The operator of Dundee Airport is taking safety actions, intended to prevent a recurrence."
The AAIB report added: "Dundee Airport has high ground on the approach, an offset NBD and no radar surveillance.
"This combination can result in a pilot inadvertently letting down to the NDB instead of the runway in IMC conditions, with no effective 'safety net'.
"Aviation should, however, in so far as possible, be an 'error tolerant' environment."
The airport operator, Highlands and Islands Airports (HIAL), has commissioned a safety survey to consider relocating the remote NDB and other measures.
All incoming aircraft now also hear the broadcast: "Pilots are reminded that the NDB and DME are not co-located".
The aircraft was travelling from Inverness to Dundee for scheduled maintenance checks when it lost contact with air traffic controllers just a few miles west of the hub.
The wreckage of the small plane was found near the village of Abernyte about four hours after it went missing.
Mr. Thompson was from Chester in Cheshire, and MacKinnon from Ross-shire.
Accident occurred Sunday, May 03, 2015 in Dundee, United Kingdom
Aircraft: BEECH AIRCRAFT CORPORATION BEECH 95-B55, registration:
Injuries: 2 Fatal.
The foreign authority was the source of this information.
On May 3, 2015, at 1113 coordinated universal time, a Beech 95-B55 airplane, G-RICK, impacted terrain while on approach to the Dundee Airport (EGPN), Dundee, Scotland. The pilot and one passenger were fatally injured and the airplane was destroyed. Instrument meteorological conditions prevailed for the flight.
At 1120, an automated weather reporting facility at EGPN reported, wind from 90 degrees at 22 knots, visibility 5,000 meters with moderate rain, ceiling broken at 900 feet, broken at 1,600 feet, temperature 7° Celsius (C), dew point 6° C, and 996 millibar.
The accident investigation is under the jurisdiction and control of the government of the United Kingdom. This report is for information purposes only and contains only information released by or obtained from the government of the United Kingdom. Further information pertaining to this accident may be obtained from:
Air Accident Investigation Branch (AAIB)
Berkshire Copse Road
GU11 2HH, United Kingdom
Tel: +44 (0)1252 510300
Fax: +44 (0)1252 376999