AIRCRAFT ACCIDENT REPORT AND EXECUTIVE SUMMARY and Incidents Reports/9560.pdf · CA 12-12a 20 NOVEMBER 2015 Page 1 of 31 Section/division Accident and Incident Investigation Division

CA 12-12a 20 NOVEMBER 2015 Page 1 of 31

Section/division Accident and Incident Investigation Division Form Number: CA 12-12a

AIRCRAFT ACCIDENT REPORT AND EXECUTIVE SUMMARY

Reference: CA18/2/3/9560

Aircraft registration ZU-IBR Date of accident 25 July 2016 Time of accident 0630Z

Type of aircraft Bat Hawk LSA (Micro-light) Type of operation

Part 91

Pilot-in-command licence type Commercial Age 23 Licence valid Yes

Pilot-in-command flying experience

Total flying hours 235.8 Hours on type 11.5

Last point of departure Manyeleti Nature Reserve, Mpumalanga Province

Next point of intended landing Manyeleti Nature Reserve, Mpumalanga Province

Location of the accident site with reference to easily defined geographical points (GPS readings if possible)

Manyeleti Nature Reserve (GPS position: 24°31’15.60” South 031°23’07.62” East)

Meteorological information

Surface wind; Southerly/15kt, Temperature; 15°C, Visibility; Good

Number of people on board

1 + 1 No. of people injured 1 + 1 No. of people killed 0

Synopsis

The pilot, accompanied by a passenger, a game ranger from a local nature reserve, took off from a private

runway on the reserve at 0515Z, on a surveillance flight of the area. During an interview with the pilot and

the passenger, while they were still in hospital, they stated that they were airborne for approximately one

hour and fifteen minutes, when the accident occurred. While flying, they spotted animals from the air, which

the ranger wanted to photograph with his hand-held camera, and they commenced with a left-hand orbit

around the animals and a second orbit was requested as the ranger was not happy with the photographs he

took the first time around. They were flying at a height of approximately 100 feet above ground level (AGL)

according to the data obtained from the GPS unit that was on board. During the second orbit, the left wing

suddenly dropped and the micro-light aircraft went into a spin. They impacted with terrain in a substantial

nose-down attitude, coming to rest in a semi inverted attitude 17.8m after impact. Both occupants sustained

spinal injuries. The first personnel on the scene to assist them were helicopter crew members from the

South African National Parks who were flying in the area when the accident was reported to them. Both

injured occupants were airlifted by an emergency medical services (EMS) helicopter to a private hospital in

Mbombela.

Probable cause

Failure to maintain flying speed (stall), while manoeuvring the micro-light aircraft for aerial photography,

which caused the aircraft to go into a spin, with the pilot being unable to return the aircraft to normal flight

mode due to insufficient height available.

SRP date 8 November 2016 Release date


Section/division Accident and Incident Investigation Division Form Number: CA 12-12a

AIRCRAFT ACCIDENT REPORT

Name of Owner : Mpumalanga Tourism and Parks Agency

Name of Operator : Private (Part 91)

Manufacturer : Micro Aviation South Africa Ltd

Model : Bat Hawk LSA

Nationality : South African

Registration Marks : ZU-IBR

Place : Manyeleti Nature Reserve

Date : 25 July 2016

Time : 0630Z

All times given in this report are Co-ordinated Universal Time (UTC) and will be denoted

by (Z). South African Standard Time is UTC plus 2 hours.

Purpose of the Investigation:

In terms of Regulation 12.03.1 of the Civil Aviation Regulations (2011), this report was

compiled in the interest of the promotion of aviation safety and the reduction of the risk of

aviation accidents or incidents and not to establish legal liability.

Disclaimer:

This report is produced without prejudice to the rights of the CAA, which are reserved.

1. FACTUAL INFORMATION

1.1 History of flight

1.1.1 The pilot, accompanied by a passenger (a game ranger) from a local Nature

Reserve located within the Mpumalanga province took off from a private runway on

the reserve. This was a private flight conducted during day time. After take-off,

they commenced to patrol the western border in the reserve and from there, they

entered into a surveillance pattern, with the intention to document certain animal

species.


1.1.2 According to a statement from the passenger, they had planned to take off at

approximately 0415Z, but the pilot contacted him and informed him that they

needed to postpone the flight due to unfavourable wind conditions and light drizzle.

He arrived at the “airstrip” at approximately 0500Z; by then, the drizzle had stopped

and the wind had died down to a light breeze from the south. By that time, the pilot

had already completed his pre-flight inspection and indicated that they had

approximately 60 litres of fuel in the tank and would be able to fly for about three (3)

hours. They took off at 0515Z and following radio work by the pilot, broadcasting

their intentions they began patrolling the western fence from the main gate. After

completion of the western fence, they proceeded in an easterly direction, flying

along the Orpen asphalt road, which was damp from rain and they noted a rain

squall-line of clouds to the east. When they reached a position known as Nulwini

corner, they commenced with their surveillance pattern by doing transect

approximately 600m apart. While flying the surveillance pattern, they saw two

animals, which the ranger took photographs of, but was unable to get good

photographs, so he asked the pilot to orbit them for a second time. He stated that

soon after they levelled off, the left wing dipped and then “we nose-dived towards

the ground”. He then felt the wings level out as the pilot pulled back on the controls;

however, soon thereafter, they impacted with the ground.

1.1.3 During an interview with the pilot, while he was still in hospital, he stated that they

were airborne for approximately one hour and fifteen minutes when the accident

occurred. They had spotted animals from the air, and the passenger, who was

seated on the left-hand side of the micro-light aircraft wanted to take photographs of

the animals with his hand-held camera. At that stage, they were flying at a height of

approximately 400 feet above ground level (AGL). While they were in a left-hand

orbit, the left wing suddenly dropped and they entered into a high rate of descent.

The pilot indicated that he applied full power and opposite control stick input. He

was unable to arrest the rate of descent and with insufficient height available to

recover the aircraft, they impacted heavily with the ground in flat bush-type of

terrain. The micro-light aircraft was in a substantial nose-down attitude on impact;

the nose gear assembly was bent backwards and the lower glass fibre cabin/cockpit

structure was deformed and the right main landing gear strut assembly broke off.

The propeller struck the ground 5.2m after the first impact mark, after which the

right wing struck a tree and the aircraft nosed over, coming to rest in a semi-

inverted attitude against large shrubs.

1.1.4 The pilot, who was conscious, indicated that he managed to undo his safety

harness and crawl out of the cockpit/cabin area. He then assisted his passenger to


undo his harness and he also crawled out of the wreckage. The pilot got hold of his

portable global position device (GPS), which was still in a working condition and his

cell phone and contacted the responsible person at the head office in Mbombela,

informing him of the accident. He was also able to provide him with their

geographical position, which he obtained from the GPS unit.

1.1.5 The responsible person in Mbombela then contacted the operational manager of

the South African National Parks (SANParks) Airwing at Skukuza camp in the

Kruger National Park, who established communication with one of their helicopters

that was operating in the area. The crew flew to the accident site, where they found

the wreckage and the two injured occupants lying on the ground. They covered

them each with a space blanket and waited for rangers to arrive and secure the

area. They flew back to Skukuza camp where they uplifted two medical doctors

and returned to the accident site.

1.1.6 Both occupants sustained spinal injuries. They were stabilised on the scene by the

two doctors who had been flown in from Skukuza camp, as they waited for the two

emergency medical services (EMS) helicopters to land at the scene to hand over to

their medical personnel. The two injured occupants were airlifted to a private

hospital in Mbombela, where they were admitted and subjected to several medical

tests.

1.1.7 The accident occurred during daylight conditions at a geographical position that was

determined to be 24°31’15.60” South 031°23’07.62” East at an elevation of 1510

feet (460m) above mean sea level (AMSL).

1.2 Injuries to persons

Injuries Pilot Crew Pass. Other

Fatal - - - -

Serious 1 - 1 -

Minor - - - -

None - - - -


1.3 Damage to aircraft

1.3.1 The micro-light aircraft sustained substantial structural damage, which was beyond

economical repair. See photographs of the damage to the aircraft under

subheading 1.12 of this report.

1.4 Other damage

1.4.1 Minor damage was caused to surrounding vegetation. The fuel tank was ruptured

during the impact sequence and a substantial amount of fuel leaked from the tank

onto the soil as the wreckage was pushed into an upright position, see figure 1.

Figure 1. Fuel leaking from the ruptured fuel tank.

1.5 Personnel information

1.5.1 Pilot-in-command

The pilot is the holder of a commercial pilot licence. According to available

information, he had conducted his conversion onto the Bat Hawk type aircraft on

Wednesday, 20 July 2016. During a conversation with the flight instructor who


signed him out in his logbook, he indicated that it was a type familiarisation, as the

pilot already had the Bantam B22J on his licence, which was a similar type of micro-

light aircraft to the Bat Hawk. A Civil Aviation Authority (CAA) form; with reference

number; CA 61-09.7 “Notification of Aircraft Differences or Familiarisation Training”,

was signed off by the flight instructor, indicating a flight time of one hour and twenty

four minutes.

The pilot had also written a type conversion technical examination on the micro-light

aircraft. This was a generic test form consisting of four pages, indicating the aircraft

type to be a VL-3 Flamingo. This was an open book examination.

In the pilot accident questionnaire (CAA from CA 12-03), subheading I, the pilot

indicated (his opinion as to what caused the accident) that they encountered a gust

of wind from the South while in a left orbit, and the left wing stalled, and they

entered a spin.

Nationality South African Gender Male Age 23

Licence number 0272453291 Licence type Commercial

Licence valid Yes Type endorsed Yes in logbook

Ratings Night rating

Medical expiry date 28 February 2017

Restrictions None

Previous accident

According to available records, the pilot was involved

in a previous accident on 28 May 2012, when he flew

an aircraft bearing the registration ZU-DDV. He

experienced an engine shutdown in flight and then

executed a forced landing on the parking area of the

Mbombela Stadium. The engine shutdown was

attributed to fuel exhaustion.

Flying experience:

Total hours 235.8

Total past 90 days 30.9

Total on type past 90 days 11.5

Total on type 11.5

*NOTE: The flying hours in the table above include the one hour and fifteen


minutes, which was the duration of the accident flight. The duration of the accident

flight was obtained from the Garmin Aera 500 global positioning system (GPS) unit

that was on board.

1.6 Aircraft Information

1.6.1 The aircraft

It features a strut-braced high-wing, a two-seats-in-side-by-side configuration open

cockpit, fixed tricycle landing gear and a single engine in tractor configuration. As

a conventional 3-axis light sport aircraft LSA, the Bat Hawk does not rely on pilot

weight shift to affect control. Twin seats are positioned side by side for full dual

control and both crew members are well protected from the weather by an

aerodynamic fibreglass pod and large wrap-around windshield. The cockpit is

very similar to that of a helicopter with excellent forward visibility as well as on

both sides.

Several important designs are incorporated into the Bat Hawk, which include a

large six-cylinder Camit engine with an all-up weight of 540 kg, strong main gear,

large ‘bush’ tyres, hydraulic disk brakes, large fuel capacity (80 litres), luggage

area, MGL Engine Monitoring System, strong wing spars and wing struts and a

streamlined nose pod.

Figure 2. A photograph of the micro-light aircraft ZU-IBRAirframe:


Type Bat Hawk LSA

Serial number MA14-37

Manufacturer Micro Aviation South Africa Ltd

Year of manufacture 2014

Total airframe hours (at time of

accident) 74.5

Last annual inspection (hours & date) 62.1 8 October 2015

Hours since last annual inspection 12.4

Authority to fly (issue date) 15 October 2015

Authority to fly (expiry date) 7 October 2016

C of R (issue date) (present owner) 25 March 2014

Operating categories Private

Engine:

Type Camit 3300 SLRE

Serial number 33 SLRE 0002

Hours since new 74.5

Hours since overhaul TBO not yet reached

Propeller:

Type P-Prop

Serial number N-3627

Hours since new 74.5

Hours since overhaul TBO not yet reached

1.6.2 Weight and Balance

Item Weight

(kg)

Arm

(mm)

Moment

(W x A)

Aircraft empty weight 266 450.7 119 886.2

Pilot 70 516 36 120

Passenger 110 516 56 760

Baggage 7 935 6 545

Fuel (40L estimated) 30 935 28 050

Total Weight 483 512 247 361.2


The maximum take-off weight for this micro-light aircraft was 540kg according to the

Bat Hawk Flight Manual, Section 2, pg. 4 as well as Section 6, pg. 4. The aircraft

was last weighed on 24 March 2014 and the basic empty weight was calculated to

be 266 kg.

Baggage: There were two headsets on board the aircraft, the pilot’s flying

bag/folder, 3 containers of engine oil with a capacity of 1l each, a first aid kit, a

digital camera, a Garmin Aera 500 GPS, a GoPro camera, a bundle of keys, and

two 500ml bottles of water. The combined weight of these articles was estimated to

be approximately 7kg.

The CG limitations were as follows:

Forward - 470 mm

Aft - 603 mm

The CG position was determined to be 512 mm, which was within the operating

limitations of this micro-light aircraft. It should be kept in mind that the passenger

was 40 kg heavier than the pilot and was seated on the left-hand side.

1.7 Meteorological information

1.7.1 The weather information that was entered into the table below was obtained from

the pilot questionnaire.

Wind direction 180° Wind speed 5kts Visibility Good

Temperature 15°C Cloud cover 4/8 Cloud base 1 000 feet

Dew point unknow

n

1.7.2 An official weather report was obtained from the South African Weather Services

(SAWS). See data below:

Satellite image (Figure 3)

The Day Natural Colours satellite image of the MeteoSat Second Generation (MSG)

satellite observed broken to overcast low level clouds at 0630Z (See satellite image


on the next page). The FAKN METARs for 0600Z and 0700Z reported broken

clouds at 500 feet and overcast clouds at 1 000 feet AGL. The geographic

coordinates of the scene of the accident are indicated on the satellite image on the

next page.

Figure 3. Day Natural Colours MSG satellite image taken at 0630Z on 25 July 2016

Surface data

The 0600Z meteorological aerodrome report (METAR) for FAKN indicates broken to

overcast low level clouds:

FAKN 250600Z 08007KT 7000 FEW004 BKN005 OVC010 12/10 Q1026

Wind direction and speed 080° / 7 knots

Visibility 7 000 metres

Cloud cover few at 400ft AGL, broken clouds at 500ft

AGL and overcast clouds at 1000ft AGL

Dry-bulb temperature 12°C

Dew-point temperature 10°C

Pressure altitude 1026 hPa

NOTE: The accident site was located 54 nm (100 km) to the northeast of the Kruger

Mpumalanga International Aerodrome (FAKN).


1.7.3 The 0400Z and 0700Z METARs for Hoedspruit Air Force Base (bearing ICAO

designation - FAHS) on the morning of 25 July 2016 indicate the following weather

conditions:

FAHS 250400Z AUTO 19011KT //// // ////// 14/12 Q1023=

FAHS 250700Z AUTO 19009KT //// // ////// 15/13 Q1024=

Over the three hour period between the two METARs, the wind remained out of the

south and the temperature and dew-point increased by 1°C respectively.

The 0700Z terminal aerodrome forecast (TAF) for Hoedspruit Air Force Base

(FAHS) indicate the following weather conditions:

TAF AMD FAHS 250700Z 2507/2518 16013KT 9999 OVC020 PROB30 TEMPO

2507/2510 5000 -RA BKN010 TX18/2512ZTN15/2518Z=

The Air Force Base (FAHS) was located 20 nm (37km) to the northwest of the

accident site.

1.7.4 Weather information was also obtained from the helicopter crew who were the first

responders to the scene of the accident. According to the pilot, the on-board

instrumentation of the helicopter (AS350B3) they were flying indicated the wind

during landing at the accident site to be from the south at 15 knots gusting 20 knots.

1.7.5 Three other pilots in the area were contacted, who also fly Bat Hawk micro-light

aircraft and they indicated that they decided not to fly on the morning of 25 July

2016 as the prevailing wind was approximately 15 knots gusting 20 knots, with low

cloud and light drizzle in the area. Two of these pilots fly from Hoedspruit Civil

Aerodrome and the other pilot from Tshokwane, which was located approximately

16 nm (30 kilometres) to the south of the accident site.

1.7.6 Figure 4 on the next page indicates the wind speeds at Hoedspruit Civil Aerodrome

on the day of the accident. This aerodrome was located 24nm (45km) to the

northwest of the accident site. The information was obtained by courtesy of one of

the pilots operating from the aerodrome. This was a privately-owned weather

station with the anemometer and the wind vane installed at hangar 15. In order to

read the data, it should be noted that the orange/yellow coloured line (top of table)

represents the maximum wind speeds, while the blue/grey line indicates the

average wind speed, and the green line indicates the minimum wind speeds. The


data were recorded in 10 minute intervals in knots. Acknowledgment of source:

http://iweathar.co.za/stations.php

Figure 4. The wind data for 25 July 2016 from the weather station located at Hoedspruit Civil Aerodrome

1.7.7 In a statement from the passenger, he indicates that the take-off was postponed by

one hour due to unfavourable winds from the south and light drizzle. When they

took off at 0515Z, the drizzle had stopped and the wind strength was light from the

south. The cloud cover varied between 6/8 to 8/8, with a ceiling of more than 2 000

feet above ground level (AGL) as the tops of the Drakensberg were visible.

Visibility was good with the temperature between 14°C and 15°C.

1.8 Aids to navigation

1.8.1 The micro-light aircraft was equipped with a magnetic compass.

1.8.2 Also on board was a Garmin Aera 500 global positioning unit (GPS). This was a

standalone unit (not panel mounted). The GPS remained intact and functional after

the accident. The pilot used it to obtain the geographical position of the accident

site from where he phoned the responsible person in Mbombela on his cell phone,

advising him of the accident and providing him with the geographical position of the

accident site.

1.9 Communication

1.9.1 The micro-light aircraft was equipped with a VHF radio.

1.9.2 For traffic below the Hoedspruit terminal control area (TMA), the designated VHF

frequency was 119.00 MHz, and for general traffic in the area, the frequency was

124.80 MHz, which was the frequency selected by the pilot for the flight.

http://iweathar.co.za/stations.php


1.10 Aerodrome information

1.10.1 The accident did not occur at or near an aerodrome.

1.11 Flight recorders

1.11.1 The micro-light aircraft was not equipped with a flight data recorder (FDR) or a

cockpit voice recorder (CVR), nor was it required by the regulations to be fitted to

this type of aircraft.

1.11.2 There was a GoPro camera mounted to the micro-light aircraft structure. According

to available information, the camera was not activated prior to the flight, therefore

there was no data available from it. The camera was removed from the wreckage

by the first responders to the accident site and was kept in their safety and later

returned to the aircraft owner. The investigator had to depend on the information

provided to him in this regard as the camera was removed from the aircraft

structure prior to his arrival on site the following morning.

1.11.3 A data card was removed from the on-board MGL Stratomaster Xtreme engine

monitoring system (see figure 5). The card was undamaged and was downloaded

with the assistance of the manufacturer of the instrument, MGL Avionics. The data

on the card dated back to 14 October 2014 and appears to show initial ground-

based break-in profile runs. There was no recorded data on the card following 14

October 2014, nor was the date and time stamp set on the instrument.


Figure 5. The engine monitoring instrument with the data card still secured

Figure 6. Data card removed from the on board engine monitoring system

1.11.4 Garmin Aera 500 GPS

The data card still inside the instrument.


Also on board was a Garmin Aera 500 global positioning unit (GPS). This was a

standalone unit (not panel mounted). The GPS remained intact and functional after

the accident. The flight track information was downloaded from the unit for the

accident flight. The first screen shot, figure 7 on the next page, displays the

track/pattern that was flown during the surveillance flight. On the fifth (5th) leg flying

the horizontal tracks, as viewed from top to bottom, the pilot executed several orbits

to the left. He then continued flying the pattern, and during the ninth (9th) leg, he

again entered an orbit to the left. It is during this phase of the flight that the

accident occurred. The data that were downloaded from the unit indicate that

during the second turn, index marker #894 the ground speed of the micro-light

aircraft suddenly decayed from 84 km/h (45 knots) at 08:30:13 AM to 32 km/h (17

knots) at 08:30:16 AM. This accounts to a speed decay of 52 km/h (28 knots) over

a period of 3 seconds. The index marker #896 was captured 5 seconds later at

08:30:21 AM, the ground speed was then captured at 2 km/h. The height flown

during the surveillance pattern varied between 80 - 150 feet above ground level

(AGL).

Figure 7. GPS profile of the surveillance pattern that was flown


The screen shot in figure 8 below displays the last phase of the flight. It was

significant that the second orbit initiated by the pilot, was much tighter than the first

orbit. It was during this orbit that the accident occurred. The blue line as well as the

yellow straight line tracks from the point of impact should be ignored; as this was

post impact movement that was captured on the unit.

Figure 8. GPS flight profile displaying the last phase of the flight prior to ground impact


Figure 9. Some of the GPS parameters including the accident phase of the flight (Index # 894, 895, 896)

1.12 Wreckage and impact information

1.12.1 The micro-light aircraft impacted an open section of ground that was surrounded by

bush-type of terrain in a game reserve on a heading of 060°M. It was evident that

the aircraft was in a substantial nose-down attitude on impact as the nose wheel

assembly bent backwards approximately 90°, and was compressed into the lower

fibreglass nose pod/canopy structure, which displayed compression deformation as

a result of the impact. Adjacent to the first ground marking to the right was where

the right main gear impacted with the ground and it was severed from the structure


and propelled forward several meters.

Figure 10. An aerial photograph of the wreckage (courtesy of a pilot from SANParks airwing)

Figure 11. First ground impact markings and final position of the wreckage

First ground impact marking

Right main wheel impact marking

First point of impact


Figure 12. Deformation of the nose wheel and the lower nose pod/cabin structure

Five point two (5.2) meters after the first ground impact marking, the wooden

propeller made contact with the ground, which indicated that the aircraft was in a

substantial nose-down attitude at that stage, as the engine was mounted above the

cabin/cockpit area. The wooden propeller was shattered, with several pieces visible

along the impact line until the final position of the main wreckage. Approximately

5m further on the right, the wing collided with a tree and the micro-light aircraft

nosed over, coming to rest in a semi inverted attitude against some large shrubs.

The distance from the first impact mark to where the wreckage came to rest was

17.8m.


Figure 13. Position of the wreckage as it came to rest

Figure 14. A view of the engine in an inverted attitude and broken propeller blades


Figure 15. These items were removed from the baggage compartment behind the cabin

1.13 Medical and pathological information

1.13.1 Not applicable.

1.14 Fire

1.14.1 There was no pre- or post-impact fire.

1.15 Survival aspects

1.15.1 The accident was survivable. Both occupants were properly restrained by making

use of the aircraft equipped safety harness. Due to the high rate of descent, the

aircraft impacted the ground heavily in a substantial nose-down attitude and both

occupants suffered spinal injuries.

1.15.2 Two emergency medical services (EMS) helicopters were dispatched to the scene

from where the two injured occupants were airlifted and admitted to a private

hospital in Mbombela. Before the helicopters arrived on scene, the two injured

occupants were attended to by two doctors who had been flown to the scene from


Skukuza camp in the Kruger National Park (KNP).

1.15.3Tests revealed that the pilot had suffered a T8 and T9 vertebral compression

fracture. The passenger sustained an L1 and L3 vertebral compression fracture.

He underwent spinal surgery in July 2015, which resulted in a fusion to his L4, L5

and L6 vertebrae; the fusion remained intact.

1.16 Tests and research

1.16.1 No tests or research were conducted.

1.17 Organisational and management information

1.17.1 The aircraft was registered in the name of a provincial entity, which dealt with

tourism and parks. The pilot made his services available on a “freelance” basis and

was not employed by the entity at the time of the accident. A signed letter was

presented to the investigator to substantiate this agreement. The passenger (game

ranger) on board the micro-light aircraft was an employee of the provincial entity

and was on official duty at the time of the accident. The accident occurred within

the boundaries of a Nature Reserve under governance from the provincial entity.

1.17.2 The micro-light aircraft was maintained by an Approved Person with stamp #274

under the Approved Person Scheme from the Aero Club of South Africa. The last

maintenance inspection prior to the accident flight was certified on 8 October 2015

at 62.1 airframe hours. Following the maintenance inspection, the micro-light

aircraft had flown a further 12.4 hours.

1.18 Additional information

1.18.1 Interview with the passenger

The passenger was also interviewed, while he was in hospital. He indicated that he

accompanied the pilot on a private flight, which entailed a border/fence patrol, and

from there they started flying a surveillance pattern over the reserve, documenting

the location of certain species of animals. He indicated that the take-off was

delayed for approximately one hour due to unfavourable winds and light drizzle.


The accident occurred during the surveillance phase of the flight, when he

requested the pilot to fly another orbit (left-hand as he was seated on the left)

around the animals in order for him to take better photographs. While in a left-hand

orbit, the left wing of the micro-light aircraft suddenly ‘dropped’ and the rate of

descent started to increase considerably with the micro-light aircraft in a substantial

nose-down attitude. The pilot was unable to arrest the rate of descent and they

impacted with the terrain. He also submitted a statement with regard to the

accident.

1.18.2 Instrument panel

The micro-light aircraft was equipped with a limited instrument panel as can be

seen in figure 16 on the next page. The airspeed indicator was an electronic

display unit (MGL Stratomaster Velocity) with a monochrome display. The turn and

slip indicator was installed below the airspeed indicator and next to it on the right

was an MGL electronic engine monitoring system. The unit, left top, which appears

to be a standalone unit, was a VHF radio.

Figure 17 displays a photograph of the instrument panel of another Bat Hawk micro-

light aircraft, which was taken by the Investigator at the manufacturing facility of

these micro-light aircraft. It was added for illustration purposes as it was fitted with

a conventional analogue airspeed indicator. The airspeed indicator was colour-

coded red, yellow, white and green for easy reference to the pilot, whereby the

critical airspeed range as well as the normal operating range of the aircraft as per

the pilot operating handbook (POH) are displayed.


Figure 16. The instrument panel of ZU-IBR

Figure 17. Conventional airspeed indicator installed in another Bat Hawk

VHF Radio

Airspeed indicator

Turn and slip

Engine monitoring system

Airspeed indicator


1.18.3 Spin

Source: https://en.wikipedia.org/wiki/Spin_(aerodynamics)

“A spin is a special category of stall, resulting in autorotation about the vertical axis

and a shallow, rotating, downward path. Spins can be entered intentionally or

unintentionally, from any flight attitude if the aircraft has sufficient yaw, while at the

stall point. In a normal spin, the wing on the inside of the turn is stalled, while the

outside wing remains flying; it is possible for both wings to be stalled, but the angle

of attack of each wing, and consequently its lift and drag, will be different. Either

situation causes the aircraft to autorotate (yaw) toward the stalled wing due to its

higher drag and loss of lift. Spins are characterised by high angle of attack,

an airspeed below the stall on at least one wing and a shallow descent. Recovery

may require a specific and counterintuitive set of actions in order to avoid a crash.

A spin differs from a spiral dive in which neither wing is stalled and which is

characterised by a low angle of attack and high airspeed. A spiral dive is not a type

of spin because neither wing is stalled. In a spiral dive, the aircraft will respond

conventionally to the pilot's inputs to the flight controls and recovery from a spiral

dive requires a different set of actions from those required to recover from a spin.

How a spin occurs

Many types of airplane will only spin, if the pilot simultaneously yaws and stalls the

airplane (intentionally or unintentionally). Under these circumstances, one wing will

stall, or stall more deeply than the other. The wing that stalls first will drop,

increasing its angle of attack and deepening the stall. At least one wing must be

stalled for a spin to occur. The other wing will rise, decreasing its angle of attack,

and the aircraft will yaw towards the more deeply stalled wing. The difference

in lift between the two wings causes the aircraft to roll, and the difference

in drag causes the aircraft to yaw.

One common scenario that can lead to an unintentional spin is an uncoordinated

turn toward the runway during the landing sequence. A pilot who is overshooting

the turn to final approach may be tempted to apply rudder to increase the rate of

turn. The result is twofold: the nose of the airplane drops below the horizon and the

bank angle increases. Reacting to these unintended changes, the pilot may then

begin to pull the elevator control aft (thus increasing the angle of attack), while

applying opposite aileron to decrease bank angle. Taken to its extreme, this can

https://en.wikipedia.org/wiki/Spin_(aerodynamics)

https://en.wikipedia.org/wiki/Stall_(flight)

https://en.wikipedia.org/wiki/Autorotation_(fixed-wing_aircraft)

https://en.wikipedia.org/wiki/Aircraft_principal_axes#Vertical_axis_.28yaw.29

https://en.wikipedia.org/wiki/Angle_of_attack

https://en.wikipedia.org/wiki/Airspeed

https://en.wikipedia.org/wiki/Spiral_dive

https://en.wikipedia.org/wiki/Angle_of_attack

https://en.wikipedia.org/wiki/Lift_(force)

https://en.wikipedia.org/wiki/Parasitic_drag

https://en.wikipedia.org/wiki/Coordinated_flight

https://en.wikipedia.org/wiki/Coordinated_flight


result in an uncoordinated turn with sufficient angle of attack to cause the aircraft to

stall. This is called a cross-control stall, and is very dangerous, if it happens at low

altitude, where the pilot has little time to recover. In order to avoid this scenario,

pilots are taught the importance of always making coordinated turns. Certificated,

light, single-engine airplanes must meet specific criteria regarding stall and spin

behaviour”.

1.18.4 Bat Hawk Flight Manual

Spin Recovery (Section 3, Pg. 4)

“In the event of an inadvertent spin, the following procedures must be followed:

- Close the throttle

- Centralise the ailerons

- Apply full opposite rudder:

Spin to the left – apply right rudder

Spin to the right – apply left rudder

- Progressively move the stick forward (down elevator) until the spin stops

- Raise the nose and recover as per the stall recovery procedure”.


1.19 Useful or effective investigation techniques

1.19.1 No new methods were applied.

2. ANALYSIS

2.1 Pilot

The pilot was the holder of a valid commercial pilot licence. He had conducted his

familiarisation flight onto the Bat Hawk type aircraft on Wednesday, 20 July 2016,

which was endorsed in his pilot logbook. The accident occurred five days after he

had completed his familiarisation on the aircraft type. His flying time on the Bat

Hawk aircraft was 11.5 hours, which included the accident flight. The flight was

categorised as a surveillance flight, which included aerial photography (wildlife), this

was a new type of flying for the pilot and something he had limited exposure to. He

was dependant on the guidance of the ranger on the profile he had to fly, as he was

not subjected to a dual check ride by a pilot experienced in the field prior to him

flying solo in this type of environment. The pilot most probably became distracted,

while manoeuvring the micro-light aircraft in order to position it as such that the

ranger was able to take good photographs of the animals on the ground. While

manoeuvring, he failed to monitor the airspeed, which was an electronic

monochrome unit, the prevailing winds from the south had an impact on the speed

and flight characteristics of the micro-light aircraft and they entered into a spin. The

passenger indicated that the micro-light aircraft was in a steep nose-down attitude

towards the ground. According to the data obtained from the GPS, they were most

probably at a height of approximately 100 feet above ground level when they

entered the spin. The pilot immediately identified the situation and initiated a

recovery, but due to the low level operation, he was unable to return the aircraft to

normal flight before ground impact followed. From the ground impact markings, one

can conclude that they were in the process of recovering from the spin, but were too

low.

2.2 Machine (Aircraft)

The micro-light aircraft was properly maintained and the last annual inspection prior

to the accident flight was certified on 8 October 2015. The airframe hours were low

for an aircraft that was more than two years old already. The investigation found

that the integrity of the aircraft was not compromised and flight control continuity


was ensured. The engine delivered power on impact with the spinner displaying

evidence of high revolution rotation during ground impact and the propeller was

shattered in pieces that were found scattered along the impact path. There was still

ample fuel on board and the fuel filter to the engine was free of contamination. The

pilot indicated that he had not experienced any flight control related problems or

engine related malfunction with the aircraft and the engine responded accordingly

when he applied power close to the ground.

The instrument panel contained limited instrumentation, and basically all the

instruments apart from the turn and slip indicator were of the electronic display type.

This included an electronic airspeed indicator with a monochrome display, which did

not provide the pilot with any critical ‘colour’ speed indications as depicted in the

analogue airspeed indicator in figure 17 of this report, which was installed in

another Bat Hawk aircraft. The analogue gauge was not only larger in diameter

than the electronic gauge it was also easier to view for the pilot, especially with the

pilot flying from the right-hand side as was the case on this flight. The electronic

airspeed indicator was regarded to be not the most suitable instrument for the

operational application this micro-light aircraft was utilised for at the time of the

accident flight.

2.3 Environment

Several other pilots that reside in the area of the accident site, who also fly Bat

Hawk micro-light aircraft, were interviewed with regard to the prevailing weather

conditions on the morning of 25 July 2016. They all concurred that they decided not

to fly due to a strong southerly wind in the area, which they estimated to be

between 15 to 20 knots. The pilot of ZU-IBR opted to fly, after the flight was

postponed for one hour due to unfavourable winds and drizzle. According to

available information, the surface wind was light by the time they took off. Neither

the pilot nor the passenger made any reference to the wind strength again after

they became airborne. It should be kept in mind that they were airborne for one

hour and fifteen minutes by the time the accident occurred. By that time, the wind

conditions might have changed substantially from what they were like when they

took off and could have had a profound effect on the flying characteristics of the

micro-light aircraft, especially while manoeuvring in flight, which the pilot was doing

when the aircraft suddenly dropped its left wing and entered into a spin.


The possibility that the pilot lost focus during this phase of the flight by focusing on

the animals on the ground and not monitoring his airspeed could not be excluded as

this was a new type of flying for him.

3. CONCLUSION

3.1 Findings

3.1.1 The pilot was the holder of a valid commercial pilot licence. He had conducted his

familiarisation onto the Bat Hawk type aircraft five days before the accident flight,

which was endorsed in his pilot logbook.

3.1.2 The pilot was the holder of a valid aviation medical certificate that was issued by a

CAA approved medical examiner.

3.1.3 The micro-light aircraft was in possession of a valid Authority to Fly.

3.1.4 The last annual inspection that was carried out on the micro-light aircraft prior to the

accident flight was certified on 8 October 2015 at 62.1 airframe hours.

3.1.5 There was adequate fuel on board the micro-light aircraft for the flight.

3.1.6 The micro-light aircraft was found to be loaded within the weight and balance

limitations for the flight.

3.1.7 The GoPro camera that was installed on the micro-light aircraft was undamaged;

however, it was removed from the aircraft structure prior to the arrival of the

investigator on site. According to available information, it did not contain any

footage pertaining to the accident flight.

3.1.8 The GPS unit that the pilot utilised during the accident flight was undamaged;

however, the unit was removed from the accident site prior to the arrival of the

investigator on site.

3.1.9 The data from the GPS was downloaded by the pilot and the data file was

forwarded to the Investigator via e-mail. The data were viewed with the assistance

of a service provider that specialises in these types of devices and the flight route

and parameters captured by the device could be viewed.


3.1.10 The data from the GPS unit indicated that the speed, which was ground speed, was

captured at 84 km/h (45 knots) and 3 seconds later, the speed had decayed to 32

km/h (17 knots), and 5 seconds later the speed was 2 km/h.

3.1.11 The minimum manoeuvring speed (Va) of the Bat Hawk micro-light aircraft was 63

knots indicated airspeed (KIAS); this information was available on a placard on the

instrument panel, with the never exceeded speed (Vne) being 92 knots.

3.1.12 The weight and balance was within the prescribed limits; it should, however, be

noted that the passenger, who was seated on the left side, was 40 kg heavier than

the pilot, which could have had an effect on aircraft controllability.

3.1.13 The structural integrity of the micro-light aircraft was not compromised, flight control

continuity was ensured, and the engine delivered power on impact.

3.1.14 The initial take-off time was postponed for one hour due to unfavourable winds and

drizzle in the area.

3.1.15 The prevailing wind conditions at the time had an aerodynamic effect on the flight

characteristics of the micro-light aircraft.

3.2 Probable cause:

3.2.1 Failure to maintain flying speed (stall), while manoeuvring the micro-light aircraft for

aerial photography, which caused the aircraft to enter into a spin, with the pilot

being unable to return the aircraft to normal flight due to insufficient height available.

3.3 Contributory factors:

3.3.1 The prevailing wind from the south during the accident flight was something the pilot

had not monitored adequately, while he manoeuvred the micro-light aircraft during

low level flight.

3.3.2 This was a low level operation, which limited the altitude available to recover the

aircraft.

3.3.3 Lack of experience by the pilot on the micro-light aircraft type.


3.3.4 Lack of experience by the pilot in surveillance and aerial photography flying.

3.3.5 Inadequate monitoring of the airspeed by the pilot, while he was manoeuvring the

micro-light aircraft for aerial photography.

3.3.6 The electronic airspeed indicator was found not fit for the application in which the

micro-light aircraft was utilised at the time as it did not display critical airspeed

colour markings for quick pilot reference.

4. SAFETY RECOMMENDATIONS

4.1 It is recommended to the Director for Civil Aviation that all Bat Hawk micro-light

aircraft that will be operated in the surveillance/aerial photography application their

airspeed indicator be reviewed with a possibility of mandating that aircraft be

equipped with an airspeed indicator that displays the critical airspeed regimes in

colour, similar to the analogue unit as displayed in figure 17 of this report for pilot

reference as the correct speed limitations needs to be adhered to in order to ensure

the aircraft sustains normal flight during surveillance/aerial photography operation.

4.2 It is recommended to the Director of Civil Aviation that in the process of issuing a

Certificate of Airworthiness or an Authority to fly SACAA obtains photographs and/

or details of the interior of such an aircraft, which should be kept on aircraft file or

database. Photographs/ locations of components and or instruments are a very

important part of accident investigation for reference purposes and in many

instances, aircraft are extensively damaged or destroyed by fire, which leaves the

investigators without a detailed photographical history of that aircraft, and in turn

makes difficult for IIC due to lack of reference. It is further recommended that if

any aircraft are modified, especially when an avionic systems had been modified

such modifications should be kept in aircraft file of aircraft database for future

reference.

5. APPENDICES

5.1 None.

Documents

AIRCRAFT ACCIDENT REPORT AND EXECUTIVE SUMMARY and Incidents Reports/9560.pdf · CA 12-12a 20 NOVEMBER 2015 Page 1 of 31 Section/division Accident and Incident Investigation Division