Air Safety

The same question enters your head as you arrive at the site to start the investigation, but you immediately force it from your mind. “You are here to gather all the evidence first, then come to a conclusion, not vice versa. ” Should you make up your mind first, you will always find evidence to back you conclusions, always! You’ll disregard any evidence that does not agree with you.

It happened to you once because the cause of the accident looked so obvious, and two weeks of very hard work went right down the drain. Not very good for the ego. You had to go right back to square one and start again. Never again, and certainly not this time!

As you are setting up, you overhear two of the rescue personnel discussing the accident. “Probably pilot error,” one says. God you hate that expression! It reminds you of the days gone by, when the accident report had to nominate one primary cause. All other causes were listed as contributory causes. In 99. 9% of occasions, a pilot’s failure to cope with a situation is the proximate cause of the accident. This was often incorrectly stated as the primary cause.

Having to nominate a primary cause focussed the investigations towards the events immediately prior to the accident. All other causes tended to become less important, were often not rectified, and all encompassing ‘pilot error’ findings were common. Little or no attempt was made to find out why the pilot failed to cope.

Today a lot more is known about the limitations of humans in the role of pilot. There have been quantum leaps in areas such as engineering, and so you know there will be a better than 90% chance that this accident will have been caused by human factors. About the only time you hear ‘pilot error’ mentioned these days is in the lay media, certainly not in an accident investigation. The term is simply not specific enough, and just drips with connotations of incompetence and culpability.

You feel quite secure in the knowledge that the investigation you are about to undertake will add to flight safety. You will gather the evidence, build a sequence of events that lead to the accident, then decide which events in the sequence were causes. Recommendations can then be made to eliminate those causes, so as to prevent their recurrence in a later chain of events.

It is a tried and proven system these days, we are learning more and refining the system every day. However, it still saddens you, because you know you are probably going to find a sequence of hazards, insignificant on their own, lined up like ducks in a row and culminating in the accident. You also know that those hazards could have been discovered and eliminated by an annual flying safety survey. However, this time it has taken a fatal accident to find them. 0430: (alarm rings) “Oh groan just another 5 min. ”

0530: “Oh Christ I’m late . . . lets see 10 min to dress, 30 min to the airport, 10 min for a quick plan and . . . yep, wheels in the well by 0630 . . . no problems!”

0550: (In the car) “Yeah no problems, quick plan, weather will be okay . . . always is this time of the year. NOTAMS? . . . probably the same as yesterday . . . no drama . . . Threshold displaced R/W 25 due works. Warming up early this morning . . . could really hack a cuppa . . . no time, with luck planning will be smooth. Only a ferry flight, but the Boss wants the jet there on time. Some big wheels are in to check out the mines. Looks like I’ll get to the airpor t five minutes earlier than I thought . . . Great, I’ll have time to call Judy for her birthday before I go.

0620: (Walking out to the aircraft) “Yep . . . the jet, she looks fine. A quick 360 around, pull the pins and covers and we’re away!” 0630: “Full power, Ts and Ps are in the green . . . rolling! Love these bizjets, they really move! Positive rate of climb, gear up, flaps up, lights . . . SH. . !! Nose gear is still down! Better slow up . . . ” 0632: ( ATC) “Rescue one SCRAMBLE, grid A3, bizjet, POB 1 . . . SCRAMBLE!”

Evidence

The weather conditions were: Wind 250/5, Vis 10km, C AVOK, Temp 24 deg C, QNH 1021.

The wreckage, consistent with that of a slow forward speed impact, was distributed over an area of 30m long by 15m wide.

Examination of the engines showed them to be developing full power at impact. This was supported by inspection of the engine instrumentation and thrust levers. All certification and maintenance records were in order.

The airframe was found relatively intact. Flight controls were examined and found to be in working order at impact. Investigation of flight instrumentation confirmed a 25 deg left wing low and 15 deg nose down attitude at impact. All airframe certification and maintenance documentation were in order, and there were no recent, nor significant, unserviceable items logged. The only anomaly was, the main undercarriage which was up with the nose gear down. Additionally, the nose gear up lock pin was still fitted.

The pilot was considered by the Chief Pilot to be of an above average standard. He was an experienced pilot who had recently transferred from another aircraft type in the company. Throughout his conversion course he had performed admirably.

Both the Pilot and Meteorological Briefing Officers were familiar with the mishap pilot. They noted an unusual haste and shortness, contrary to the mishap pilot’s generally thorough and professional approach. Whilst short, his disposition was described as cheerful. However his plan showed several errors, omissions, and corrections.

The air traffic controllers, at the time of the accident, reported that after takeoff, the mishap pilot advised of a landing gear malfunction. The pilot then requested a low level righthand circuit.

This request was approved as the tower controllers assumed that the low level circuitwas to facilitate inspection of the landing gear. Both controllers observed the aircraft enter an early right downwind position, when the nose attitude seemed to raise slowly yet abnormally high. The nose was then observed to rapidly descend with a marked left wing drop. The aircraft then impacted the ground. No transmission other than the request for the low level right hand circuit was heard from the pilot.

Probable causes

The possibility that this accident occurred as a result of one or more of the following causes needs to be considered:

a. Physical incapacitation of the pilot; b. Engine failure or malfunction; c. Airframe failure or malfunction; and d. Loss of control by the pilot.

a. Incapacitation: The possibility that pilot incapacitation has been a factor in this accident is considered unlikely. Whilst the autopsy did reveal limited food intake on the morning of the accident, suggesting no breakfast was consumed, it was not considered to have impaired the pilot’s physical or mental ability. No physical signs of incapacitation were found.

b. Engine Failure/Malfunction: Neither engine failure nor malfunction is considered to be a factor in this investigation. The engines were found to have been developing full thrust at impact.

c. Airframe Failure/Malfunction: The only airframe failure or malfunction found was that of the nose wheel down and the up locking pin still in place. No other failure or malfunction was found.

d. Loss of Control: The only plausible cause of this accident is the pilot’s failure to maintain control of his aircraft in that he became channelised with the nose gear problem and stalled at low level. This is supported by the impact debris pattern and witness statements. The finding that the engines were developing full thrust at impact, would suggest the pilot did attempt to recover the situation, albeit too late.

Sequence of events

1. The nose wheel locking pin warning flag had become detached from the locking pin approximately three weeks prior to the mishap.

2. (Cause) The locking pin flag had not been written up as a discrepancy in the tech log.

3. The three other pilots qualified on the mishap aircraft type had become familiar with the discrepancy on the mishap aircraft.

4. The mishap pilot had not previously flown the mishap aircraft, and had not been told of the discrepancy.

5. The mishap pilot slept late, did not consume a breakfast, and rushed both his flight plan and preflight.

6. (Cause) The mishap pilot failed to remove the nose wheel locking pin during his preflight.

7. After takeoff the nose wheel remained in the down position.

8. The pilot informed the tower and requested a low level circuit.

9. The tower approved the request in the belief that the circuit would be used for an inspection of the landing gear.

10. (Cause) During the turn downwind, the pilot became channelised with the nose gear problem, failed to recognize the stall warning indications, and allowed the aircraft to stall from an irrecoverable height.

11. The aircraft crashed and was destroyed, killing the pilot.

Recommendations

1. Company personnel be briefed on the importance of discrepancy entries in the tech log.

2. Company pilots be briefed on the importance of not allowing themselves to be rushed. Emphasis needs to be placed on pilots being more assertive, and accepting the consequences of making required operational decisions, albeit that such decisions may be brought about by non-operational factors (eg waking up late).

3. Additional sequences be included in the company conversion to adequately familiarise pilots with the stall characteristics of the aircraft type.

4. The company review their safety promotion and monitoring programs with attention to the following areas:

a. Introduction of safety refresher lectures;

b. Establishment of an Incident and Accident review forum;

c. Appoint a pilot to undergo a Flying Safety Officers Course; and

d. Conduct periodic Safety Surveys.

Have you an air safety story to tell? Particularly one with a lesson that might save other pilots from making a similar error of judgement? If you have, write to Macarthur Job, cl- Australian Aviation, PO Box 3105, Weston Creek, ACT 2611. Contributors to this series are assured their anonymity will be fully respected!

Postscript

So there we have it, the accident investigation is complete. Weeks of interviewing, organising and reviewing technical reports, and assembling your thoughts on paper. Thinking back t that first day, your hunch about that chain of seemingly insignificant events was correct, but who would have thought a nose wheel locking pin flag.

It all seems blindingly obvious in hindsight; it a/ways does. These insignificant hazards just seem to roll around until they at are to pop up in sequence. The only safe way is to identify and eliminate them. A good annual flying safety survey would have identified discrepancies not written up, as well as pilots feelings of shortcomings in the conversion course. Such a tragic loss of human life. But then it always is.