Aero Commander accident in the past - Reason for in-flight break-up.

[Centaurus]

The Aero Commander has an unmistakeable howling engine noise while climbing. I first heard, then saw, an Aero Commander climbing away from Essendon to the north-east this morning Monday 30 September. The weather over the Melbourne area was overcast with very strong gusting northerlies and the Aero Commander was making slow headway. Soon it would be over high terrain and although I haven't seen the flight forecast experience says it is probably moderate to severe turbulence below 10,000 ft over the ranges.

It got me thinking about the Aero Commander that broke up in mid-air on the same route as todays flight I saw. That was quite a few years ago and the circumstances leading to the in-flight break up could not be satisfactorily explained by ATSB. The sequence of break-up was explained after the wreckage was examined. Apparently there was no sign of structural failure that initiated the disaster. Whatever happened it was quite sudden and may have been caused by pilot input in turbulence. A radar picture revealed a series of sharp turns and loss of altitude before the break up started to occur. Hundreds of Aero Commanders and other general aviation light twins would have flown over the same route in the same conditions over many years yet none came to grief.

I wondered what really happened and no doubt many other people wondered the same thing. The ATSB report was, as usual, bland and gave no Most Probable Cause -other than a forensic examination of the break up sequence. I have always considered it a pity that ATSB are constrained by their legislation not to state a Most Probable Cause of an accident, if the facts cannot be proven with certainty.

I understand the American NTSB are required by law to give a Most Probable Cause if they are unable to pin down what actually happened to cause the accident sequence.

In the case of the Aero Commander crash in question, the pilot and her passenger were killed. Accidents involving in-flight control surface failures have often been caused by over-controlling by flight crew. The American Airlines A300 rudder fin failure was caused by over-controlling on the rudder by the first officer for example.

I wondered if over controlling by the Aero Commander pilot in severe turbulence - or even by her passenger somehow on the controls with her in fright - may have been a Most probable Cause? Something happened and few have talked about it...

[Jack Ranga]

Got a couple of good mates flying those aircraft for GAMS, that accident often crosses my mind. They are a great bunch of pilots & and good to work with on 'the other side.' I know they have procedures for turbulence but it must be on their minds as well.

It is fact Australia is a more litigious society than the US. Something to be proud of, NOT. What is the point of the ATSB if they can't state a probable cause? Could save quite a few million if it was disbanded.

[PLovett]

A similar one also without satisfactory explanation.

Investigation: 200400610 - Aero Commander 500-S, VH-LST (http://www.atsb.gov.au/publications/investigation_reports/2004/aair/aair200400610.aspx)

[Desert Flower]

The Aero Commander has an unmistakeable howling engine noise while climbing.

Unmistakeable yes, but I certainly wouldn't call it howling. Droning maybe, but not howling. I used to love hearing the sound of ACZ (the Augusta Airways mail plane) fading into the distance as it headed north every weekend on the (then) World's Longest Mail Run.

DF.

[dubbleyew eight]

an aero engineer commented to me once that the combination of bends in the centre spar had been thought to cause about twice the stresses in the centre section as originally calculated.

[Frank Arouet]

I could be wrong, but from memory, the Essendon crash involved an overloading of newspapers which was thought a a contributing factor.

[j3pipercub]

Paul Phelan’s article in The Australian on Fri 10 Aug. [Archive] - PPRuNe Forums (http://www.pprune.org/archive/index.php/t-287677.html)

[TWT]

VH-YJB ?

Investigation: AO-2007-029 - In-flight break-up - Clonbinane, Vic; 31 July 2007, VH-YJB, Rockwell, Commander 500S (http://www.atsb.gov.au/publications/investigation_reports/2007/aair/ao-2007-029.aspx)

[Mango]

Unmistakeable yes, but I certainly wouldn't call it howling. Droning maybe, but not howling. I used to love hearing the sound of ACZ (the Augusta Airways mail plane) fading into the distance as it headed north every weekend on the (then) World's Longest Mail Run.

Desert Flower, didn't you like the drone of the chieftain as it headed north every weekend as well? I enjoyed having a cuppa tea and biscuit in your donga after refuelling.

Sorry for the thread drift. Memory nostalgia overcame me.

[gfunc]

The meteorology of the 2007 case was examined in detail by one of my colleagues at Melb Uni with their student. The "executive summary" was presented at a local conference:

www.amos.org.au/documents/item/393


Gareth.

[compressor stall]

Interesting summary.

I'll remember [d^2ψˆ ( z ) ]/ dz^2 + m^2ψˆ ( z ) = 0 next time it's rough. :}


We'll never know if it was over controlling, or controlling and getting out of phase, or just the sheer force of what they went through.

I look back on what I took Shrikes through back in the day. It was years before this accident and Google so I had a deal of confidence (ignorant perhaps) in the airframe. With no radar, you'd look for the tops of the wet season CBs from a distance, dial 200 on the ADF to check, pick a heading, stick to that and wait till you were spat out the other side.

[zanzibar]

The breakup most likely resulted from an encounter with localised and intense turbulence, or from an elevator control input, or from a combination of both.

That do you Centaurus, from the ATSB report?

[Desert Flower]

Desert Flower, didn't you like the drone of the chieftain as it headed north every weekend as well? I enjoyed having a cuppa tea and biscuit in your donga after refuelling.

Lol, that's when it did depart north & not break down somewhere! Mind you, the Aerocommander had its share of breakdowns over the years too. Nostalgia for sure!

DF.

P.S. The "donga" now sits in my yard alongside the house. Still has all the memorabilia attached to the walls & hanging from the ceiling!

[romeocharlie]

Frank, the Essendon crash was empty bar the pilots. Still think about the old shrike on nights like tonight. I don't miss not having a wx radar.

[Centaurus]

That do you Centaurus, from the ATSB report?

Thanks, Zanzibar. I understood the only "payload" was an electrical component (maybe an alternator/generator/ starter motor) needed for another grounded aircraft. The passenger was the owner of the operation and most likely being an aviation man, sitting in the RH seat alongside of the pilot. The flight had been delayed because of the unavailability of an LAME to fly in the aircraft. Hence the operator, himself an LAME, rostered himself. While at least moderate turbulence was expected, occasional sharp or even violent gusts can be unnerving to even an experienced pilot. I recall one of the greatest frights of my flying career was experiencing violent turbulence in a Cessna 172 as a front passed over Melbourne while I was flying from Point Cook to Melbourne.

I was surprised that in the case of the 2007 Aero Commander accident, ATSB studiously avoided mentioning the possibility that, at the onset of severe turbulence over the hills in partial IMC, the passenger may have grabbed the controls in fright counteracting the pilot's input. On the other hand the passenger may have thought he could help the pilot with the controlling of the aircraft in severe turbulence? If indeed that was the case, things would literally have gone downhill from there.

Perhaps in their deliberations, investigators should make mention in some detail what actions by the pilot could be discounted. By not doing so, it leaves the situation wide open to healthy speculation just as I am doing right now. After all, ATSB alluded to possible over-controlling of the elevators. But not by whom

[compressor stall]

I flew the man many times, and never once did he touch - or appear to want to touch - any control.

[Tee Emm]

I flew the man many times, and never once did he touch - or appear to want to touch - any control.

As a matter of interest, how many of those flights were in violent turbulence IMC?

[avconnection]

This has been discussed at length in numerous threads all of which are merged, but:

It's worth noting that the passenger was the foremost expert on Aerocommanders in the southern hemisphere (if not the world), and the pilot was one of the more experienced on the line at the time. At 7,000ft the aircraft is nestled right into a reasonable turbulence penetration speed at cruise settings.

With the experience onboard, a low time airframe (one of the best in the fleet) and the aircraft comfortably in its niche, you could all but rule out over manipulation.

The only freight onboard was tools and parts for repairs to another aircraft.

Anecdotally, in the past 6 years I can think of at least 5 CB penetrations by Aerocommanders, that the pilots and aircraft have come away from relatively unscathed.

[prospector]

, it leaves the situation wide open to healthy speculation just as I am doing right now. After all, ATSB alluded to possible over-controlling of the elevators. But not by whom

You may think that healthy speculation, I certainly do not. In fact I would consider your speculate ludicrous. Just because the man did not have a pilots licence, does not mean he would not be aware of the possible results of any unasked for control inputs.

[Fantome]

an aero engineer commented to me once that the combination of bends in the centre spar had been thought to cause about twice the stresses in the centre section as originally calculated.


That could probably do with some elaboration from an aeronautical engineer
knowledgeable about stressing and the loadings that occur in different flight modes. Makes you wonder whether ATSB ever consult any real boffins?


re.. .. 'Healthy speculation' . . . . . aren't you being a bit harsh there on Centaurus, Prospector ?. Pre report speculation is often ludicrous, true, but post report, and in the analysis of deficiencies in reports. . . . it's a friggin' minefield, mate. Especially when the men sent out to do the forensic don't know a tapered spiggot from a knurled flange bracket.

[zanzibar]

Perhaps in their deliberations, investigators should make mention in some detail what actions by the pilot could be discounted.

And how would that be possible with the absence of a CVR or FDR? They couldn't comment on such issues generally let alone "in some detail". Get real!!!

[AdamFrisch]

As you know there was a huge investigation into the Aero Commanders, both by CASA and FAA after a series of break ups in the 70's and 80's. None of them where conclusive. Suffice to say that the blame was put alternatively on:

1. The cold forming of the main spar, especially at Wing Station 24 where it has a kink in it.

2. The stainless steel spar strap that allegedly caused galvanic corrosion.

3. The exhaust outlet at the top of the wing, close to the spar, on some of the 500-series.

Except for the galvanic corrosion below the strap (a fix for the first break ups in itself), the others might just have been due to other causes. All of them had to comply with expensive AD's and inspections and it couldn't be ruled out they hadn't been simply overstressed. Since the report and inspections started, no new in flight breakups have been recorded.

I don't know if it was a design fault or not, but my personal opinion is that I suspect it was something else. Commanders are haulers and semi-bush planes and get considerably abused, overloaded and flown in the harshest of environments by probably less than care-taking wage pilots. What do I base this my assumption on? Well, multiple things. Now, as the use of Commanders has diminished and they're not as readily operated anymore, the problems stopped. Like I said, there hasn't been any more break ups that I know of, even though the fleet has aged considerably. Secondly, I know John Towner of Central Air Southwest from my time as a Commander owner, and in his freight business he has for decades flown 500B's in the harshest of environments. Night freight in the cold midwest, medical freight, checks etc. He has at least one 500B still working for him with over 20.000hrs on the airframe. He has numerous 500's with well over 15.000hrs on them, still in service.

You simply don't get to those numbers with a weak main spar.

Here's CASA's report:

http://flysafe.raa.asn.au/scratchbuilder/aero_commander_structural_failures.pdf

[haydnc]

I once had a conversation with a Kiwi pilot regarding the AC's in flight break ups. Apparently an AC (series unknown) in kiwi land was believed to have broken up in flight due to an earlier undercarriage incident.

The commanders have a bolt which keeps the main wheels tracking in the right direction (it could be on the scissor link but i'm unsure now - i am not an engineer!). If this bolt fails, the wheel can rotate and cause considerable force on the gear leg.

Having such long legs (YEAH!!) a twisting force is easily transferred though to the spar.

A similar one also without satisfactory explanation.
Investigation: 200400610 - Aero Commander 500-S, VH-LST

"LST" had a similar undercarriage incident with its previous operator turning from the runway to the taxi way at DPO. This point i don't believe is raised in the report.

Maybe something worth some consideration.

No, i'm not an engineer, yes I do have time on type, no I havnt had much to do with commanders in a few years.

[LeadSled]

Folks,
I would have thought, by now, that the problems of various Aero Commanders was well known, at least to those of us with long involvement, several have been mentioned here.

One of the interesting characteristics of the aeroplane's wing (more or less common to all the earlier models is the wing structure and behavior with speed.

In two of the accidents here, the wing or wings failed in downward bending, the failure happens at a change of section in the area just outboard of the engines (not to be confused with failures at the wing root, in the area of the cold bent spar section) .

The current turbulence penetration speed is quite low, it is possible to cause a failure in downward bending at dive speeds beyond the Vne, that the aircraft can achieve. It would seem likely that a similar failure could happen at lower speeds (but above the turbulence speed) in severe turbulence.

The Aero Commanders are wonderful aeroplanes, but they must be flown withing their flight envelope, and they do have rather a large number of ADs.

I know of no other light twin that has flying characteristics that come anywhere anywhere near the AC 500 range. CASA's predecessors had a range of Aero Commanders over the years, from the 560/560E thought to, finally, the Gulfstream 1000 (aka AC695A) -- the ultimate Turbo Commander.

Tootle pip!!

Re: Sheet tearing howls, that is from models fitted with geared engines, and exhaust pipes feeding into a "drain pipe" augmenter (like Queenairs).

[Volumex]

There was a Commander that the CAA landed gear up, and then the crash comic gave some really complicated reason why it was the planes fault. It was some time in the late 80's / early 90's.
Blind Freddy could tell by the photo that the pilot just landed gear up - the photo in the crash comic showed that the nose gear doors were shut.

[LeadSled]

Volumex,
CASA predecessors were very good at landing gear up: one of the 695As was landed gear up twice. If you are going to land gear up, an Twin Commander is the aeroplane, with a bit of luck, all you will have is gravel rash along the belly.
Also the DCA NSW Region C-310 --- twice.
The DH 125 at Avalon.
Dove at Camden
Plus a few write-offs, both in "normal" operation and in "test flying" (a nice little Italian amphib. at the bottom of Pittwater, the severely damaged Merlin at Mangalore. ) and some amazing incidents like dead-sticking an F-27 onto Mudgee after shutting down the wrong engine.
The there was the C-310 that ran out of motion lotion and wound up in a paddock.
Tootle pip!!

[Fantome]

ahhh .. .. . Leadie . .. . what a memory you have for all them expensive landings!

Ballarat February 1986 . . . two day ripper airshow (Col had the MkV111 out for her show debut) . ... we were over from slowbart with CLV filled up with plane buffs. Got there fairly early on the saturdee. Charlie alpha something (the departments 'blue canoe') calls up coming in. We're all standing round having just deplaned. Someone says 'looks like the department's here ' pointing to said balus on a shortish final. ."No mate' says old mate . . ..'can't be one of them . . . he's got his gear down"

this propensity to forget the odd pre-landing incidental probably explains in part the inordinate time the gents who flew all this equipment round the country and beyond at our expense. . . the long long time they took to start engines and the longer time that elapsed before they even thought about brakes release.

Jeeeesus chriiiist almighty . . . it used to send the flight sisters and other occupants of the old NSW air ambulance hangar at Mascot spare. . . . the shrill whine of old CAO that went on and on and on after the whackers had lit the fires. One time dear old Harry Papadopoulous, the cleaner, went out and waved his mop at them from a hop and a step in front of them. Can still see the two bland faces peering out from close behind the glass. . . struggling to comprehend why the man with the mop is so agitated.

(Russ Evans NEVER. He who gave a 15 year old neophyte wagging school a circuit at Canberra in the C310C VH-CAZ. Bliss. Them were the days.)

[john_tullamarine]

Russ Evans .. one of nature's finer gentlefolk.

I remember, fondly, a day relaxing at RNAC (shortly after I had finished my PPL there with Stan Hone, as I recall) ... Russ and Henry turned up in the prototype AirCruiser and beat the daylights out of the clubhouse and flagpole for a while before giving it away and landing for a convivial ...

Just as well no-one thought to grab a camera and record it all for posterity ... probably would have come back to haunt us all in our ever increasing nanny state society ...

I recall Stan's tales regarding Russ' trips to RNAC to renew Instructor Ratings .. demo forced landings invariably involved turning the ignition off, throwing the keys into the rear baggage compartment and then watching the subsequent deadstick onto the aerodrome.

[Dora-9]

CASA predecessors were very good at landing gear upLeddy, they weren't bad at taking off with the gear (prematurely) up either! AC680 (or a 560?) at Wittenoom George, c. 1969? It didn't do the pilot's career any harm though, he went on to become the Regional Director, but maybe that's the Public Service mentality...

[Fris B. Fairing]

LeadSled

Dove at Camden

Do you have any more details of that one?

Rgds

[Frank Arouet]

I understand from the depths of history somewhere, a DCA or CAA Commander under maintenance, and during a hangar party, had a child retract the undercart while Dad, who was a functionary of said organization, helplessly looking on in the cockpit.

This came out during the PPRune discussions on the Bonanza "gutzer" at Goulburn, but we won't go there.:oh:

[john_tullamarine]

a DCA or CAA Commander under maintenance

Merlin, perhaps as I recall, sometime after I had left the Flying Unit. Know the dad well. Red faces all around as one would expect.

There, but for the grace .. go many of us, I suspect.

I suspect that a few systems changes were put in place to fix the gaping holes in procedure ...

[Frank Arouet]

Yes a Merlin. I've had numerous phone calls to that effect.

Disregard everything after I understand:hmm:

[john_tullamarine]

Disregard everything after

Love it.

[Wally Mk2]

'JR' I often wonder what it's like to drive for Gam's these days. I know they pumped out a lot of good all round drivers years ago who could think on their own two feet something that Airlines don't want as they just want 'puppets'.

I also recall at times the AC's launching out of EN on a less than ideal morning for the usual gaggle of bank runs into the soup whilst we couldn't turn a wheel (B200's) due poor viz, these guys must have had special dispo's for zero viz Ops:E Not what ya know but who ya know I guess:-)

Many years ago when 'Notty' was a young scrawny apprentice I/we could see he was going to be an authority on AC's & became so but he never had an interest in flying himself funnily enuf, well as far as I can recall.
Those screaming AC's unique sound especially the Grand's will stay in my head long after I hang up my flying goggles:)

Wmk2

[LeadSled]

Folks,
Funnily enough, my introduction to Aero Commanders was watching an inadvertent gear up at Biggin Hill in 1962, the first time the owner had flown the aeroplane since his last gear up. Back to the hangar, again!!!
Re. Russ Evans, last time I spoke to him, about a year ago, he was alive and well and still going strong. I got the very distinct impression he doesn't think much of CASA.
Re. the Dove at Camden, sorry, before my time there, one of the many stories of Camden.
The fabled Blackjack Walker also has a certain propensity to neglect to dangle the Dunlops --- including on a test flight of a Baron, after DeHavs repaired a --- guess what ---- gear up??? Huge cloud of dust on the old 05/23 YSBK.
Tootle pip!!

[tail wheel]

Blackjack - rest his soul - also had a propensity for underestimating the required quantity of motion lotion to get from A to B, or in one of his adventures, Cairns to Port Moresby in a Baron.

"Instrument rating? God no, who needs one of those?"

[NOSIGN]

Centaurus, I think that with the recent extreme weather in Melbourne, we have all been thinking about GAM, Steve and Janelle. A few days before your post, I was standing on the apron watching/ waving to YJO as they flew away, thinking about what if anything has changed.

I don't have the diagrams or memory at hand but when I flew for GAMS, I often wondered about the damage that the ladder, hydraulic cans and oil bottles loaded in the rear compartment could do in severe turbulence. Out of interest, does anybody know how these bits survived the accident?

I have experienced severe turbulence on three occasions - each instance in Victoria and on two occasions, associated with mountain wave. The two wave instances were sudden jolts - not unlike somebody hammering a piece of tin with a punch. The other CAT was associated with an approaching squall line (150nm away from memory) tracking from Williamstown to Pt Cook. That was like several vertical jolts, but before one direction could finish, the next would take effect. That went on for several seconds. Each severe turbulence encounter involved more vertical than horizontal motion.

[Fantome]

On descent into Hobart in the Heron, (last balloon wind at 10,000 240/60) smooth as silk, till about 5000, then whammo into the lee of Wellington.

5 kg extinguisher in it's bracket on the rear bulkhead instantly becomes loose object. If someone had been in the rear seat closest, they would have received a bump upon the scone. . or worse.

used to watch the wings flex on the C402s. and used to watch them not flex on the Queenairs. One O'Dea, navy pilot from Nowra, ETPS graduate and all that . . .. he looked out from the front right seat one morning while we were being bounced about in the B80 Goulburn to Sinney,,, and says in a pleasant terse sort of a way . .. ' Rather have a wing with a bit of give'.

[DanS333]

Hi People,
I basically grew up at Essendon as my old man was an Airport Safety Officer there. I would run around that airport like I owned the place. I would be in and out in all the hangers annoying everyone but Notty always had time for me. I would jump in any Test flight I could, the most memorable being in “The Grand” UJA full noise whilst doing a “Missed Approach”
I remember when the Air Races were held in Tassie, Notty entered UJA with Guy Burke flying. They mounted a G meter on the dash, it had a big red line on 4g with Notty stating don’t go over that!
There was a video taken from inside and Burkie had it pegged on the redline all the way round the course.
I can also recall one of the Department’s G1000’s on its belly with its leg’s dragging behind it like a dead duck after the U/C was selected up instead of the flaps after landing.
As for the Dove at Camden, I have been researching Doves for my website and facebook page http://dh104preservation.webs.com/ (http://dh104preservation.webs.com/) & https://www.facebook.com/pages/DH104-Dove-Preservation-Group/523574834358937 (https://www.facebook.com/pages/DH104-Dove-Preservation-Group/523574834358937) (Shameless plug)
It was C/N4400 G-AMXV was to be VH-DHD but was Written off before that reg was taken up. Details below come from Wiki.

On 2 December 1952, Reginald C. Adsett of Arncliffe, Civil Aviation Department, senior examiner of airmen was fatally injured and T. H. Dalton, of Manly and R. J. Harris, of Bankstown, Civil Aviation Department examiner of airways were seriously injured in a takeoff incident at at Narellan, near Camden, Australia.
I have not been able to find any official report. Maybe some can help out?
Cheers, Dan

[mustafagander]

I am reliably informed that because of that crash Tas Dalton became the first one-eyed CPL in the country.

I'm not sure about the whereabouts of Tas Dalton, but I'm quite sure that among the records of de Haviland, where ever they are, would be a report. After all it was their aircraft and Tas was their employee.