The Partenavia unexplained accident at Essendon in 1978
 

The No 59 tram from Airport West to the CBD parallels Matthews Avenue as is it travels South towards Niddrie. Passengers seated on the left of the tram can just see the threshold of Essendon Runway 08 on the left and Cameron Street on the right. Houses are situated most of the way on the west side of Matthews Avenue stretching from the suburb of Airport West to Niddrie. I travel the route often on my way to Niddrie Public Library and as we pass Essendon Airport, it brings back memories of an aircraft accident that cost the lives of a young family.

It was into some of these houses on the night of 10 July 1978, at 1853 hours, that a Partenavia P68B crashed with three crew aboard. It had departed from Runway 26 with the intention of executing a simulated engine failure after take off followed by a circuit and landing. The simulation was by cutting the mixture control of the starboard engine at 200-250 feet above ground level at the same time the wing flaps were retracted from setting 15 degrees to UP.

Seconds after power was re-introduced on that engine the Partenavia adopted a six degree nose down flight path until colliding with houses on Matthews Avenue. The aircraft caught fire immediately which resulted in the deaths of several occupants of the house. The crew of the aircraft survived.

The cause of the accident was that the aircraft became grossly out of trim at a height which did not permit time for the crew to effect recovery. The manner in which the out-of-trim condition occurred was unable to be determined and the possibility of a trim system malfunction cannot be eliminated. However, the more likely explanation is that the command trim switch was activated unknowingly.

See the following accident report:

https://www.atsb.gov.au/media/24632/197802547.pdf

Inadvertent elevator electrical trim use when practicing an emergency is a an event most flying instructors may have met at some time in their instructing career. This usually happens when the electrical elevator trim button is situated on the control wheel and the pilot's thumb may be resting close to the switch. It can happen in times of stress and is not noticed until a severe out of trim is felt.

For example, a case occurred recently when a go-around was attempted in a Boeing 737 flight simulator. The stabilizer trim switch is thumb operated on the pilot's control wheel. As part of the go-around procedure, full power may be applied and at the same time the aircraft is rotated up to an initial pitch attitude of 15 degrees. The flaps are then normally retracted from landing flap to 15 (close enough to be the equivalent of half flap in a general aviation type aircraft.

The combination of under-slung engines delivering high power and the pitch up to 15 degrees gives a very marked pitch up moment well beyond 15 degrees if allowed to happen. Pilot action to contain the rate of pitch up includes forward pressure on the control column backed up by appropriate forward selection of stabiliser trim to contain the forces applied to the elevator. A Cessna 172 or most light singles have a similar pitch up characteristic when full power is applied in the landing configuration.

In the case of the Boeing 737 incident in the simulator, the pilot under instruction held his thumb forward on the stabiliser trim much longer than necessary and the result was the aircraft eventually bunted over and dived into the ground. The stabiliser trim wheel of the 737 makes a loud clacking noise when operated (a design feature to alert the crew). At the time of the go-around the aircraft was on autopilot. When the pilot disconnected the autopilot, a warning siren sounded which he failed to cancel.

The noise of the siren was so loud that it disguised the clacking noise of the moving stabiliser trim and this was missed by the student. This all happened together in a time of increasing stress caused by the late go-around. It shows these sort of unexpected events can occur in any aircraft type.

A similar thing happened to a Boeing 737 of Flydubai Airlines that crashed during an IMC go-around at Rostov-on-Don, Russia, in March 2016,that killed all on board. See link below

https://en.wikipedia.org/wiki/Flydubai_Flight_981

That sounds amazingly lucky!

If I had my finger on that switch, I would have wished one extra did not survive - maybe not every day but many.

If that were the case.

Alan Baskett retired only a few years ago and is still alive and healthy. He was at the Casey airfield reunion at Moorabbin a couple of years ago. He was an outstanding and respected instructor. I was an early student of Speedair at Essendon having followed him there from Casey in Berwick.

The ATSB report does not cover the mandatory AD that resulted from Partenavia as a result of this accident to limit pitch trim travel.

The report is inconclusive as to whether it was runaway trim or inadvertent trim activation by the pilot under supervision. It was told to me at the time by the crew that it was runaway trim that they were physically unable to manually over-ride it. The report acknowledges this and the Partenavia AD is witness to this.

In my opinion, a factor that should have been considered,. but was not, is the poor town planning which did not align a street with the runway or provide any public open space that would provide additional safety off the end of runway 26.

I don't know if Alan still posts .. he PM'd me at one stage after a comment I made in the long-winded Essendon thread. Had a quick look in the history but was unable to identify the PM to check if he still posts.

Only flew with him several times .. including an endorsement on the Partenavia in question a while prior to the prang. He appeared to be quite a straight down the line operator and, certainly, a pleasant chap with whom to interact about the airport.

Always wondered about that one especially regarding a failed TO of a Partenavia at Melton the previous year. BASI said the unable to get airbourne was due to 50 (lbs/kg?) overweight.

the P68 has a pretty average trim system. it relies on the tension of the cable around the trim wheel to stop any slipping and has no physical cable lock. therefore if you move the trim to each stop and continue to operate the trim wheel it will misalign the indicator with its actual position.
I have seen pilots hold the trim wheel and operate the electric trim which slides the cable around the trim wheel and misaligns the indicator as well.
I used to check the correct alignment before every flight which takes about 2 mins.
for those that don't know gently trim full nose down, outside align the stab with the neutral rivet, stab trim should be level or slight down.
the fuel system is an even greater marvel of engineering and can cause accidents if not treated correctly.
thankfully been a while since I have had any involvement with the partbanana

Oh yes, it certainly has! This report is worth looking at, although I think it says rather more about the driver and the training system than the aircraft fuel system...

FP

It doesn't help that they seemingly re-designed the fuel system for each individual aircraft, and the differences can be very subtle as well

biggest problem I have heard of was after maintenance the fuel selector knobs were not installed at the correct positions, there is no master spline and can be fitted in potentially 20 odd positions due to its design, if the control cable tubes are not lubed then the selector drives slip as well throwing it out. hope the new ones are better!

And then there was this incident in January 1992. See http://www.atsb.gov.au/publications/investigation_reports/1992/aair/199201201/


While the title "Hard landing" is quite misleading there are some aspects of this event that appear to relate to original post i.e. Loss of elevator control.

IIRC the accident killled 4 children their mother and grandmother. It was so tragic.

I used to pass the little brown roofed house on the block years ago wondering if the childrens father was still alive.

The block was recently subdivided and a second house built on it.

Thread drift from original subject of trims. Some years ago there were several Partenavias at Essendon. I recall trying to turn the fuel selectors to their various positions while teaching a student. They were all unacceptably stiff to operate and sometimes needed two hands. I went across the tarmac and tried the same with the other Partenavias. Same defect. I wrote the defects up in the MR much to the annoyance of one operator. I was told it was a well known characteristic with these aircraft and to accept it.

Later I read a UK accident report where a Partenavia was en-route from the Channel Islands to an airport in southern England when an engine failed. I forget the finer details but the female pilot went to use the cross-feed system but was unable to physically move one of the fuel selectors into the cross-feed position. The aircraft was ditched due inability to cross-feed and some passengers were drowned. The pilot survived to tell the tale. The Brits CAA issued an AD that warned of the danger of Partenavia defective fuel selectors.

I contacted BASIS in Canberra with a copy of the AD and evidence of my own experience with Partenavia fuel cock selectors. BASIS then issued a similar AD to Partenavia owners. In brief it required pilots to write up instances of difficult to move fuel selectors and maintenance organisations to check them on scheduled servicing cycles.

Then one day a Partenavia arrived for a 100 hourly. An LAME mate rang me and said come and have a look at this Partenavia which was undergoing other rectification. He said try to move the fuel selectors. They were jammed completely and had obviously been like that for yonks. In fact the problem was at the other end near the engines - not the selectors themselves. He suggested to his supervisor that DCA airworthiness people would be interested and should be advised as a standard procedure in view of the AD. The supervisor told him to forget that idea as the aircraft owner might get upset and go to somewhere else for future servicing.

Is it just me, but are these BASI reports posted by Centaurus a lot better than today's piffle written by the current crop of experts?

Which is why I believe today's pilots can learn from these old BASI/DCA accident reports without being ambushed by the plague of political correctness that regretfully pervades much of our Public Service reports

Is that due to the MOU [Memo of understanding] between casa as well as deficient reporting by atsb??

Only speculating!!

You need to read the old Aviation Safety Digests!!! The facts from decent investigation, plus the real world judgement from someone like Centaurus.

What's been learnt though? Whether the report was written by BASI or the ATSB pilots are still going VMC into IMC and crashing, pilots are still running out of fuel and crashing and pilots are still mishandling engine failures in twins and crashing.

Please excuse the thread drift, but with regard to the Partenavia at Moorabbin in 1992, does anyone recall if a nosewheel change was carried out on that aircraft not long before that which involved a number of people sitting on the tailplane? Or was that a rumour?

What actually happened
 

Special InvestigationReport79-1


This Accident Investigation Report prepared by the Dept while appearing to be extensive and detailedin its investigation of this accident is in fact deficient in its pursuit of the subject matter to its logical extensionof the ramifications of the total assessment of all the facts.
The Dept have touched on the matter of pilot strength when they investigated control system failure caused by pilot input loads but choseto not detail in a similarmanner the requirements of FAR 23-143(c) which limit the force requiredto be exerted by a pilot on a temporary basis not to exceed 75 pounds
This report also omits to detail any reference to the fact that the position of the trim tab actuator was in a position that indicated that the trim tab travelwas other than that certified in Australia
This report omits to admit to the fact that the Dept failed to obtain flight test reports as required by ANO 101-22 prior to certifying the Autopilot/Electric Trim system.
This report omits to detail that the Trim Tab Travel Range was excessive to that required to comply with FAR23-689(f) which establishes total trim capacity requiredfor an aircraft.
This report fails totally to address the fact that the Electric Trim System was never flight tested correctly as required.
This report by not completely investigating all aspects of the Electric Trim System was able to minimize the design and certification deficiencies to enable the claim of pilot error to be raised by stating
“However,the more likely explanation is that the command trim switch was activated unknowingly.”
This cannot be supported by any supported by any evidence as the coroner found at the inquest.
The CAUSE as listed in this report is incorrect and misleading and would be more accurateif listed similar to the following.-
Cause
The cause of the accidentwas that the aircraftbecame grossly out of trim at a heightwhich did not permit time for the crew to affect recovery.The trim system design allowed control forces to be generated that exceeded pilot control force limits to be exceeded by a substantial amount. The manner in which the out of trim conditionoccurred has not been determined and the possibility of a trim system malfunction cannot be eliminated


All this was only achieved after many numerous legal orders were obtained as the Department did everything they could to stall and delay proceedings.
I think their tactic was to maximize the delaying tactics hoping that I would tire of the whole process and just go away.
I had to get a court order to get them to let me get copies All the documents were laid out on a conference table in a boardroomin no logical order.I then had to identify he relevant documents that I required to be copied. It ended up taking a full days work to sort out.
In the end I ended up accepting an offer as I had been made aware that if I didn’t,Legal Aid would withdraw their support and I would be on my own from a financial point of view if I didn’t accept what was on offer. So reluctantly I accepted and at the end of 1993 after repaying the workers compensation costs and paying my legal costs I received what was left.
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