CAA accident report - executive summary: BushyBaby
Date of accident: September 18 1999
Time of accident: 1415
Aircraft registration: ZU-BCX
Type of aircraft: Bushbaby
Pilot-in-command licence type: PPL
Pilot-in-command flying experience: Total Flying Hours: 69
Hours on Type: 69
Type of operation: private
Last point of departure: Ermelo
Next point of intended landing: Secunda
Location of accident site: In a quarry on a early left-hand down-wind position for RWY 13 at Ermelo.
Meteorological information: South easterly wind of 15-20kts with good visibility; temperature 10°C.
No. of people on board: 2
No. of people injured: 0
No. of people killed: 2
SYNOPSIS
The ill-fated aircraft was one of three aircraft taking off for a flight to their destination when the pilot of number two aircraft stalled the aircraft turning from crosswind to down-wind. Due to insufficient altitude the pilot was unable to recover and crashed in a quarry north of the aerodrome. The aircraft exploded on impact.
PROBABLY CAUSE
The pilot stalled the aircraft.
Jim’s analysis
All crashes are sad, but this one is particularly heartbreaking because the poor pilot was not stepping over the line. He was not cowboying, or showing off, or doing anything illegal or even mildly stupid. It is just that at a critical time he simply stopped concentrating on the job at hand – flying the aeroplane.
We have this new pilot, taking his buddy flying and they are all going off for a fun weekend with their mates in another couple of LSAs. They fall victim of something that is often poorly understood, even by experienced pilots – the dreaded downwind turn. This crash illustrates exactly what I am talking about in my Tips & Traps article in this issue - a downwind turn is not aerodynamically dangerous, but it still kills – for a whole bunch of different reasons.
When a Bushbaby, like many other two-seaters, is carrying full tanks, two guys and a bit of gear, it is at, or close to, gross weight. It will not climb like an angel, particularly at a density altitude of 6200ft, which it was at Ermelo that day.
In addition, a flight-test report stated, “The Bushbaby is challenging to fly accurately. To maintain balanced turns, rudder input is essential and in this respect it’s not unlike a Tiger Moth. Full stick deflection is also hampered by the occupant’s legs – an unwelcome quality.”
And so we have a slightly tricky aeroplane, at gross weight, climbing badly, in turbulent air, flown by a low-hour pilot who is almost certainly concentrating on watching, and following another aeroplane. He doesn’t notice the airspeed decaying through the few knots that separate his climb speed from the stall speed. Suddenly the quarry fills the windscreen and there is no space for recovery. Very sad.
What can we learn?
• Low-level downwind turns are extremely dangerous, for several reasons that are not easy to foresee unless you know what you are looking for.
• You always need to fly the aircraft; let nothing distract you from that. It is your main job – flying the aeroplane. I suspect this guy was so interested in looking for, and catching up with, the lead aircraft that he stopped thinking about airspeed. Two guys killed themselves in UK through trying to close the door of a Cherokee just after take-off. Fly the aircraft, fly the aircraft, fly the aircraft.
• Load is everything. Most of this guy’s flying had almost certainly been in a lightly loaded aircraft that you could point at the sky and expect to climb at 1000ft/min. This day, the same aircraft was probably struggling to see 300ft/min. The pilot was sub-consciously pulling back, or trimming up, to get his usual nose attitude until he stalled the aeroplane.
• Learn to expect the illusions and the pathetic angle of climb that a low-level downwind turn will throw at you.
Jim Davis has 15,000 hours of immensely varied flying experience, including 10,000 hours civil and military flying instruction. He is an established author, his current projects being an instructors’ manual and a collection of Air Accident analyses, called Choose Not To Crash. Visit Jim's website by clicking here.