German investigators of Chilima’s June 10 plane crash expose serious flaws of radio navigation aids between aircraft crews and control towers

* Recommends that Malawi’s Minister of Defence should ensure that MDF aircrafts transporting persons are equipped with a functional emergency locator transmitter

* Ministry of Transport should ensure that up-to-date information concerning radio navigation aids in Malawi is available to aircraft crews at all times

* Department of Civil Aviation should check the proper function of the radio naviga-tion aids and update the respective information in the Malawi Aeronautical Information Publication

By Duncan Mlanjira

In its interim report of circumstances that led to the Malawi Defence Force (MDF) plane that crashed on June 10 and killed the country’s Vice-President Saulos Chilima and eight others, the German Federal Bureau of Aircraft Accident Investigation has exposed serious and concerning flaws of radio navigation aids between aircraft crews and control towers.

The interim report by investigators, Jens Friedemann and Dr Susann Winkler, concludes that Malawi’s Minister of Transport & Public Works should ensure that up-to-date information concerning radio navigation aids in Malawi is available to aircraft crews at all times.

The Department of Civil Aviation is also recommended to check the proper function of the radio navigation aids and update the respective information in the Malawi Aeronautical Information Publication (AIP).

The investigation found out that according to the Flight Information Officer at Mzuzu Airport, Global Positioning System (GPS) data showed that at 07:04hrs for Lilongwe International Airport. the airplane took off from runway 35 and one minute later during climb it turned towards the south (Fig. 1, flight path in purple).

The GPS is one of the global navigation satellite systems (GNSS) that provide geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.

It does not require the user to transmit any data, and operates independently of any telephone or Internet reception, though these technologies can enhance the usefulness of the GPS positioning information.

It provides critical positioning capabilities to military, civil, and commercial users around the world. Although the United States government created, controls and maintains the GPS system, it is freely accessible to anyone with a GPS receiver — as according to Wikipedia.

The controller at Kamuzu International Airport told the investigators that he received a telephone call from Mzuzu’s Flight Information Officer shortly after take-off that the plane will probably arrive at waypoint NALSA at 07:31hrs and estimated landing time was 07:48hrs.

At 0728 hrs, at flight level (FL) 100, the flight crew reported on Lilongwe Approach frequency with three crew members on board and fuel for a flight time of 02:30hours, according to the controller’s statement.

They said, arrival at waypoint NALSA would be at 07:32hrs and estimated landing time at 07:48hrs and at 07:50hrs, the airplane turned into the final approach of runway 14, landed two minutes later and taxied to parking position 5.

The airplane was refuelled for the flight to Mzuzu and the later planned return flight.

According to the air traffic service provider, the co-pilot had filed a flight plan for the flight to Mzuzu with the Crew Briefing Office of Kamuzu Airport and in the flight plan she had given the estimate flight time to the arrival aerodrome with 00:50hours and a maximum flight time of 04:00 hours.

At 09:05 hrs, the co-pilot reported via radio communications and requested departure information and three minutes later the engine start-up clearance.

According to the controller, he had given the flight crew the en-route clearance for a direct flight to Mzuzu at FL90 and the departure clearance at 09:12hrs and communicated the transponder code 2772.

At 09:16hrs, the airplane took off from runway 14 with three crew members and six passenger on board. The controller stated that the radar target of the airplane appeared on the monitor as it had reached about 4,800ft AMSL.

At 09:17hrs, in climb, the airplane began a left-hand turn, two minutes later the turn ended in a northern direction. According to the controller, the flight crew received the climb clearance to FL90. Later, the flight crew requested to maintain 7,000ft AMSL.

The GPS data showed that at about 09:23hrs, the airplane reached a cruise level of about 7,300ft (GPS altitude) and about one minute later, it passed the border of the airport control zone.

The flight crew informed the controller that they would reach reporting point NALSA at 09:32hrs and the airport of destination at approximately 10:05hrs. The controller passed on this information by phone to the Flight Information Officer at Mzuzu Airport.

At 09:30hrs, the controller cleared the flight crew to change frequency to 118.1 MHz. According to his statement, due to the low altitude, there was no radar contact at the time.

According to the GPS data, the airplane was flying north and at 09:32hrs was 3 NM west of waypoint NALSA at about 7,500ft. At 09:3 hrs, it began to climb and within three minutes reached about 8,600 ft.

At 09:44hrs, the airplane entered descent and at 09:50hrs, at about 1.5 NM north-west of the village Fumbawowa, it began to deviate from the direct course to the airport of destination by entering a left-hand turn.

At 09:52hrs, during the left-hand turn, at about 5,500ft, the airplane began to climb again. With a track of about 150°, the left-hand turn ended and the airplane turned right in a western direction and at 09:55hrs reached 8,100 ft, then began to descent again.

At 09:56hrs, the aircraft flew a full left-hand turn, continued in a south-western direction and at 09:58 hrs, it passed the settlement of Bokosi Kunga. One minute later, it began to turn right and within one minute reached an eastern heading, then turned to a north- eastern heading.

Altitude decreased to about 5,400ft (about 460ft AGL). Approximately 2 NM south of a wood industry plant, the airplane turned left in climb to the north. Between 10:06hrs and 10:09hrs, about 3 NM north-west of Chikangawa, the aircraft flew two full left turns with a radius of about 600m.

While doing so, it was between 500ft and 200ft AGL. From 10:09hrs on, the airplane continued the flight with various headings in a north- eastern direction, descended to 185ft AGL and then began to climb again.

At 10:12hrs, it was about 25NM south-west of Mzuzu Airport at about 7,000ft (about 1,500ft AGL). Two minutes later, it reached about 2,200ft AGL.

Then it turned in a northern direction and descended again. At 10:15hrs, it turned left in a north-western direction. Finally, it had a track of about 284° and at 10:16 hrs, it impacted the ground.

All nine occupants suffered fatal injuries and the airplane was destroyed. After a search of one day, the accident site was found.

The Flight Information Officer at Mzuzu Airport stated that at the airport, bad weather prevailed and the conditions continued to deteriorate. Since the flight crew had not reported in by 09:50hrs, he had contacted them by radio.

Five minutes later, he had tried again, both attempts failed. At 10:05hrs, he had called Lilongwe Area Control Centre to have the estimated arrival time of the airplane confirmed again.

At 10:12hrs, the flight crew had reported in on the Mzuzu Tower frequency and informed him that they were 20 NM away and intended an approach from the north.

The Flight Information Officer communicated the weather information and that runway 17 was in use. He also informed them about his observation that east, south and west of the airport visibility was about 5km.

The flight crew had wanted to fly towards Ekwendeni to see if the weather conditions were better there. At 10:17 hrs, he had contacted the flight crew by radio to find out about their altitude, but as with later attempts he did not receive any answer.

The report further says the plane was equipped for flights in accordance with instrument flight rules and with a satellite navigator Garmin Area 760 with the serial number 6HD001128.

The fuel receipt that was provided to the investigators showed that at Kamuzu International Airport, the airplane was refuelled with 483 litres of Jet A1 fuel prior for departure to Mzuzu Airport.

The BFU investigators asked German meteorological service provider. Deutscher Wetterdienst to compile a meteorological expert opinion concerning the weather conditions along the flight path and in particular in the area of the accident site but up until the publication of the report, this data was not available.

Malawi’s Department of Civil Aviation (DCA) provided the BFU with the Aeronautical Information Publication (AIP) of the Republic of Malawi, edition 21 July 2017. According to the DCA, this AIP was valid at the time of the accident.

The Flight Information Region (FIR) Lilongwe was structured as having two international airports, each surrounded by a control zone (CTR) with a radius of 20NM. The control zones extend from the ground up to 7,500ft AMSL.

Above the CTR, the Terminal Manoeuvring Areas (TMA) Lilongwe and Chileka, respectively, extended. The Control Area (CTA) Lilongwe was between FL145 and unlimited altitudes. Mzuzu Airport was located north of the border of CTA Lilongwe.

Radar coverage by air traffic control existed in both CTR, in both TMA and in the upper airspace.

The AIP Part 2 Enroute (ENR), Chapter ENR 4 Radio Navigation Aids/Systems, Sub-chapter ‘ENR 4.1’ listed the radio navigation including their coordinates, frequency, range etc.

In this list the VOR/DME VMZ north-west of Mzuzu Airport was listed with a range of 100 NM and the NDB UU (range 50 NM), among others. According to the Flight Information Officer at Mzuzu Airport, the VOR/DME and the NDB have not existed for at least 15 years.

The NDB KG located 3.9km north-west of Kamuzu International Airport was missing in this list.

The radio communications between the flight crew and the air navigation service units at Lilongwe were not recorded. Radio communications between the flight crew and the Flight Information Service (FIS) were also not recorded.

The airplane was not equipped with a cockpit voice recorder or a flight data recorder. The investigators found it that these recording devices were not required by relevant aviation regulations.

The air navigation service in Lilongwe had no recorded radar data of the two flights on the day of the accident. The navigation system Garmin Aera 760 had recorded position data (GPS position and altitude above time).

In addition to the data of the accident flight, position data of flights from 7 March 2024 onwards could be saved. The recording of the accident flight began at 0846:48 hrs at the apron of the departure airport and ended at 1016:14 hrs in the immediate vicinity of the accident site.

The Diagnostics Page was also analysed — it was determined that the GPS had switched off automatically about 2:45hrs after the aircraft’s impact (time of the accident), due to low battery power.

A day after the accident, search and rescue personnel recovered the occupants’ bodies from the wreckage and the accident site. In doing so, wreckage parts were moved from their original positions. Then the accident site was cordoned off and secured until the investigation team arrived.

The accident site was located about 34km (18 NM) south-west of the arrival airport in the Chikangawa Forest in Nkhata Bay District. The airplane crashed into the slope of a hill, which is about 1,940m (6,365ft) high, about 2km east of highway M1 and about 700m south of a settlement.

In the area of the accident, the slope had a gradient of 25-30°. During the crash, the airplane had a flying direction of about 283°.

First, the aircraft collided with the trunk of a tree with the outer part of the right wing at a height of about 4.5m above ground. Part of the honeycomb structure of the wing stuck in the tree trunk.

Based on the traces on the tree trunk and the right wing, it was determined that the aircraft did not have any relevant bank angle at the time of the collision.

At a distance of about 12m north-west of the tree, the airplane’s lower fuselage surface had impacted the ground. The right wing tip and the right aileron were laying north-west of the impact site of the fuselage.

Parts of the interior and some cockpit instruments were scattered over an area of about 60m x 25m. The main wreckage had come to rest on the slope about 80 m from the tree it had collided with.

The fuselage had come apart and the engine were torn off the wings. The cowling of both engines had fractured abreast of the first compressor stage. The propellers of both engines were torn off the shafts.

The flaps were in position 1. The flap control lever was deformed. The landing gear was extended, the landing gear lever in the position ‘Down’.

The horizontal situation indicator (HSI) and the radio magnetic indicator (RMI) on the co-pilot’s side showed a heading of 284°. The barometric altimeter on the left side of the instrument panel showed a reference pressure of 1,029 hPa and the one on the right of 1,026 hPa.

The warning and caution panel at the instrument panel was removed and seized by the BFU for further examination. The emergency locator transmitter (ELT) was found in the wreckage. The switch in the cockpit was in position ‘ARM’, the one on the ELT itself in the position ‘OFF’.

The BFU seized the Garmin Aera 760 at the accident site and later read it out at the BFU laboratory.

Eight of the nine occupants were subject to a post-mortem examination. The BFU had eight of the nine post-mortem reports available for investigation purposes. According to the post-mortem reports, the occupants suffered fatal multiple injuries in the form of high-impact trauma on impact.

Leading were severe injuries of head and thorax, followed by multiple fractures of the arms, legs and pelvis. There was no evidence of fire in flight or after the impact.

According to the Flight Information Officer at Mzuzu Airport, after he had lost radio contact, he had called Lilongwe Tower at 10:42hrs. They had informed him that they too did not have any radio contact with the flight crew.

The controller called the flight crew on the tower frequency, but could not establish contact. The flight crews of two aircraft flying at great altitudes were asked to attempt radio contact with the missing airplane. All attempts were in vain.

At 11:31hrs, at Kamuzu International Airport the rescue coordination centre (RCC) was activated. Surrounding national and international airports were contacted by phone to enquire whether the airplane had landed there.

At about 14:30hrs, search and rescue personnel from Mzuzu Airport and others arrived at the region around Ekwendeni to search for the airplane. Later witnesses came forward whose information suggested that a crash in the area of the cell tower Raiply had occurred.

Subsequently, the search and rescue personnel were sent there. According to the report of the RCC, the search was made more difficult by the low visibility.

Employees of the Malawi RCC asked the Aeronautical Rescue Coordination Centre (ARCC) at Johannesburg, South Africa, for support in finding the airplane’s ELT signal.

The following day, helicopters from Zambia, one US American military aircraft and some UAV assisted in the search. At about 10:00hrs, search and rescue personnel found the accident site and the wreckage.

Because of the missing radar coverage of the lower airspace north of the border of the TMA Lilongwe, the BFU asked the telephone company for the mobile radio data of the airplane’s occupants’ mobile devices. The data that was provided showed that four mobile devices of the three occupants had been switched on and logged into different radio cells during the accident flight.

The Emergency Locator Transmitter Narco Avionics ELT10 was mounted in the cabin on the left fuselage side next to the door. It was an ELT which transmits signals on the frequencies 121,5 MHz and 243 MHz. The ELT was examined — it was determined that it was not functioning because its battery had expired in 2004.

According to the MDF, there were no spare parts for such devices and no budget for new 406 MHz ELT. Until the end of January 2009, COSPAS-SARSAT satellites had monitored the frequencies 121,5 MHz and 243 MHz. Since 1 February 2009, the satellites only monitored the internationally agreed emergency frequency 406 MHz.

Thus, the BFU issued the two safety recommendations — to Malawi’s Minister of Defence to ensure that MDF aircrafts transporting persons are equipped with a functional emergency locator transmitter (ELT).

And that the Minister of Transport & Public Works should ensure that up-to-date information concerning radio navigation aids in Malawi is available to aircraft crews at all times and that the Department of Civil Aviation should check the proper function of the radio navigation aids and update the respective information in the Malawi Aeronautical Information Publication (AIP).