Paul Phelan’s article in The Australian on Fri 10 Aug.

[triadic]

Paul Phelan’s article in The Australian on Fri 10 Aug.


As an aviator for many years I have been a reader of Paul’s articles in various publications over the years and have met him on a number of occasions as he, unlike other aviation journalists frequents airports, aero club lounges and aviation gatherings. I have always been impressed in his efforts to bring some of the regulators habits and actions out in the open in an effort to get a better deal for the industry. As a pilot, he often writes of his first hand experiences and in an interesting and informative manner.

Having said that, I was most surprised and somewhat disappointed to read his article titled “Crashed Shrikes were overweight” last Friday. It is not an article that I would expect from Paul, but one that might come from a non-savvy junior journalist with little or no knowledge of the subject matter.

In very basic terms I believe the article is a sensational beat up following the recent tragic accident in Victoria which killed one of the most knowledgeable Shrike engineers in Australia, if not the world.

Let’s start with the headline:

Crashed Shrikes were overweight
I don’t think so! If the article is pointed at the accident in Tasmania and the recent one it is wrong! The Tasmanian Shrike had just one pilot on board and the recent accident had two occupants – far below MTOW.

“Flying at heavier weights increases the risk of structural failure, and the deadly mix of turbulence and latent fatigue can trigger in-flight break-up.”

To my knowledge the increased AUW for the Shrike which was approved by the Australian regulator (DCA) in the late 60’s/early 70’s has not been a factor in any Shrike loss in Australia.

The subject aircraft in the recent crash I understand had quite low hours for the type (less than 5000) and had only been in Australia for a short time, which means that for most of its life has been operated at the FAA MTOW. Besides, the investigation has some way to go and to presume at this early stage that fatigue was a factor is drawing a very long bow.

“In the US, their country of origin, Shrikes are limited to a 3062kg maximum takeoff weight, but when they were imported here as used aircraft, the (then) Department of Aviation issued a "supplemental type certificate" allowing them to fly at up to 3357kg, the equivalent of three extra passengers."

True. However the STC which permitted the increase was two fold in that there was a difference in the MTOW weight for IFR and VFR operations – brought about by the need to achieve a specific climb gradient for IFR ops – which it did (I participated in some of the test flights and saw the performance first hand!). The STC was issued to an organization operated by very experienced aviation professionals and to my knowledge not only was performance tested, but also fatigue issues investigated and considered. (That, at a time when the wing issues were well known) Initially the STC was available only to that operator, but due to circumstances which are not relevant to this discussion was extended to all Shrikes in Australia.

There is no mention of the VFR/IFR differences in the article.

Quoting what Gulfstream people might say or the contents of a dated report sound fine, but there are many other factors applicable and a broad and simple investigation will reveal that there are many aircraft modified by STC or otherwise from the manufacturer’s status. All such modifications are undertaken by persons approved for the purpose and it must be assumed in such cases that the applicable issues including fatigue are considered at the time. What the manufacturer might choose to do or not do is irrelevant to the discussion.

“The Shrike remains popular with commercial operators because of the weight concession, but its pilots are now worried that the average aircraft in Australia has flown about 25,000 hours at unusually heavy weights."

Wrong Paul! The Shrike is a popular aircraft because it is a good airframe, simple to operate and maintain with normally aspirated engines with a good airfield performance and a high reliability factor. The increase in the Australian MTOW gives a good aircraft some additional flexibility and to say that the majority of the hours flown are “at unusually heavy weights” is just pure bunkum!

Certainly there are some high time Shrikes about (many aircraft are these days) but to give the impression that the fleet average is 25,000 hours is nothing but a dramatic guess.

“…about 50 Shrike Commanders are still flying in Australia. More than half are registered to General Aviation Maintenance Pty Ltd, the operators of the crashed plane, and they are still certified to fly here at a 10 per cent heavier MTOW than the US regulator allows."

Yes, and those aircraft would have to be the best maintained Shrikes anywhere in the world for a fleet that size. Steve (RIP) was the Shrike Guru and over the past 30 years or so he has maintained Shrikes in a manner not normally seen in GA. He was also very much aware of the fatigue issues and spared no effort in conducting inspections in his fleet and often far in excess of the manufacturers recommendations or the regulators requirements.

Paul, you can do better than this and have done in the past. Are you short on work and need to take some of Steve Creedy's sensational pills to earn a quid? I for one hope that you can retain your professional standards in your future writings in supporting a struggling industry and not as you have in this article succumbed to the need to write such sensational uninformed dribble whilst seemingly taking advantage of a tragedy.

:mad::mad::mad:

[Captain Nomad]

Triadic - why don't you copy and paste your post into an email back to The Australian? Of course your reply is not as sensational but it would be great if the paper would print the other side of their story...:hmm:

Between this and the dribble fed from QF management it is no wonder the public has no idea and that pollies make stupid decisions regarding aviation :suspect:

[QFinsider]

What a load of crap.........

Typical journalist rubbish.

Seems a media sport to make an accusation without any knowledge of fact and a very tenuous link to recent events...

[illusion]

Having delved into this issue myself many years ago, I think he has hit the nail fairly and squarely on the head. There has never been to my knowledge any meaningful flight testing done at the higher (VFR) takeoff weight 3357kg or at the higher IFR wt of 3243kg. The reason for the increase would seem political in that when HC Sleigh imported the aircraft for the coastwatch contract, they needed the extra weight for payload/range specifications. The lack of climb performance at higher weights was more acute because of the added bubble windows and ~7 extra antennas. Also this category of aircraft is only required to maintain 5000' on one engine at ISA conditions. Not indicative of the aussie environment.
Certainly he article title is misleading and the timing is in poor taste; possibly not relevant to this crash. It must however be addressed:(

[triadic]

illusion

The reason for the increase would seem political in that when HC Sleigh imported the aircraft for the coastwatch contract, they needed the extra weight for payload/range specifications.

Your history is a bit out.... the increased MTOW was in place well prior to HCSleigh having anything to do with coastwatch, which was not until the later '70's. Sleigh's in fact imported very few of the Shrikes, having inherited them in a takeover. They all had the STC applied at that time.

And yes, flight testing was undertaken in regard to the performance issues and the results satisfied the DCA of the day.

Coast watch was a very different environment and in fact a few Shrikes were scrapped during that period, mainly due to corrosion I recall.

I am sure the latest investigation will cover off these issues. However my issue is the article.

[DutyofCare]

Triadic, an excellant posting. :D Yes I agree, Mr Phelans article was poorly timed and ill informed. Yes I agree, SK would of forgotten more on those airframes than most engineers would of known and Yes most of those aircraft are a absolute credit to him and his organisation. Interesting to note however that these crashes both involved female crew operating in turbulant conditions and at similar heights. :confused: Please Mr Phelan, now isn't the time to vent your spleen or opinion on a company you know so well. I hope to see GAM's continue to operate into the future, as I feel that with some better check/training put in place it'd be the GA example of a great company operation! :ok:

[QFinsider]

Triadic has the right information with respect to HC Sleigh...

I extremely disappointed that someone supposedly in the know with aviation chooses this time to publish that sort of crap when the industry lost the person who owns more Shrikes than any other person, at least in this country...

It is poor form, tacky and entirely bad manners...

Any one with any industry understanding would know this without being told!

[Creampuff]

Please bear this episode in mind, next time you read one of Mr Phelan’s hard-hitting exposěs on regulatory issues.

[The Company]

Yes poor timing, but look behind Paul to the editor. Would this article caused the same responses in two or three months. The issues will be researched and over time, our ever so clever regulator will come up some whizz bang scheme that is similar to 400 series sids, PA31 spars etc, that no one else in the world does or thinks necessary.

[tinpis]

Off topic a bit ,what happened to all the Shrikes parked (abandoned?) near the GA apron in Darwhine years ago?

[Jabawocky]

Ironic perhaps that both were flown by females and in turbulent conditions........but what is the point of that comment?:=

J

[PA39]

Paully Pud Puller

[tio540]

Dutyofcare

Are you suggesting the opposite sex caused the bridge collapse in the USA too? :)

[Atlas Shrugged]

I extremely disappointed that someone supposedly in the know with aviation chooses this time to publish that sort of crap ..........It is poor form, tacky and entirely bad manners...


Pretty much sums up everything that turkey has ever written!

[bushy]

Thank god we have Paul Phelan writing in aviation newspapers and magazines. He is one of the few writers who is game to write about what he sees, and says what he thinks. Most of the other aviation stuff we read in Australia is just promotional rubbish. Nice warm and fuzzy stuff that will not upset anyone, or achieve anything.

Maybe the timing was unfortunate on this occasion, but the matter should be discussed and thoroughly investigated. It's starting to look as if there really is a problem.

I do not think Paul was saying that this aircraft was overloaded on the fatal flight, or that any particular operator was knowingly overloading them, beyond normal Australian flight manual limits.
But I think we should have a good look at the logic of what comes from our authorities.

I remember, a long time ago, when the coastwatch contract was awarded to a company that was not able to carry it out. The media told us that this company was not licenced to do the work, did not have aircraft, or crews. Other tenderers that did have these things were unsucessful. The sucessful tenderer started to operate, but could not meet the requirements and major changes were made. (another operator)

It would have been about this time that the STC for a 300 kg overload of shrikes surfaced.

Let's look at other aircraft.

The Piper PA32 aircraft has to have it's wing main spar "retired from service" at 11,000 hours because of an Australian airworthiness directive, unless it can be inspected by an inspection scheme "that is approved by CASA". There is no inspection scheme that is approved by CASA. This is not required in other countries. The aircraft manufacturer says the wing spar should be inspected at 70,000 hours (yes seventy thousand hours), and there is an inspection scheme for this. CASA will not accept it.

Last time I read the notice about the CESSNA SID program on the CASA web site it concluded by saying that this would give non cessna operators a commercial advantage, and they seemed to be trying to find a way to apply similar things to operators of other aircraft, purely for commercial reasons, to even things up.

I thank god for writers like Paul Phelan, who are game to challenge the integrity of some of the things our regulator does. Most people in aviation are afraid to upset our regulator, as they are mindful of their next renewal, and/or dispensation.

(Edited only to include para breaks.)

[triadic]

I do not think Paul was saying that this aircraft was overloaded on the fatal flight

The headline said: Crashed Shrikes were overweight

What else can you make of that comment??

The sucessful tenderer started to operate, but could not meet the requirements and major changes were made. (another operator)
It would have been about this time that the STC for a 300 kg overload of shrikes surfaced.

The increased TOW STC for the Commander 500 was in place in the very early 1970's. The coastwatch contract you refer to was around Sept '87. The failure of that operator had nothing to do with Aero Commander.

It is also interesting to note that the number of in-flight failures of the model 500 worldwide are minimal (2), and the Australian STC applied to the 500S & 500U's, where there have not, to my knowledge, been any failures to date identified with the known wing problems

I agree that there is a place for writers like Paul, but to maintain his credibility he has to get it right and not stick unjustified knives into the industry that gives him work!

[To infinity & beyond]

In June 1991, seventeen senior engineers met in Seattle to discuss the safety of AeroCommanders after the twenty-third in-flight wing failure. Lawyers watchedcarefully over their shoulders. The meeting had been called by the United StatesFederal Aviation Administration (FAA) to discuss ‘wing loads, flutter, corrosion,cracking, and possible corrective action.’ How was it that such fundamental structural problems were still unresolved after forty years?

The Aero Commander typifies the practicalities of controlling fatigue in smallcommuter aircraft. The purpose of this paper is not to criticise Aero Commandersor those involved, but to draw lessons for the future - for designers, operators, regulators and all who have an interest in structural durability.

http://www.casa.gov.au/airworth/papers/AeroCommander.pdf

Not that I am suggesting this has anything to do with this particular acident, but the figure is concerning. I am not aware of a single Cessna 300 series that has had an inflight break up world wide, and Cessna have brought in the SID's programme.

[bushy]

So an aircraft that had wing fatigue problems was authorised to carry 300 kg overloads????

[Paul Phelan]

Most people who regularly read newspapers understand that it’s not journalists, but subeditors, who write the headlines. Their quite valid purpose is to attract the reader’s attention, which works, and they don’t usually tamper with detail in the text except to correct things like grammar and style.

No apologies should be expected for reporting on events that have become topical as a result of recent accidents.

Would anybody care to challenge any of the following facts? All material assertions in the article are supported by documents in my possession.
When a wing or wings, or other major airframe components separate from an airframe in flight, a structural failure has occurred.

All events related to changed Shrike maximum weights occurred before Coastwatch contracts became an issue. The aircraft were imported second-hand by one Jim Wilson and (from memory) his company was called Executive Air Services.

The Shrike Commander 500-S and -U were never certificated in their country of manufacture at any weight higher than 6,750 lb. (I apologise in advance for the use of pounds instead of kilograms but all the documentation is in pounds which were fashionable at the time.)
For 25 years the type has been approved for operation in Australia at MTOWs of 7150 lb IFR and 7400 lb VFR, under an Australian STC issued by the regulator (then the Department of Aviation) in June 1971 when the aircraft were first imported into Australia.

It has been my experience that aircraft approved at a particular MTOW quite frequently take off at that weight.

Manufacture of the Aero Commander 500-S and -U ceased in the early eighties.

The Department of Aviation never made available any flight test data or structural analysis to support the higher STC weights.

The weights were challenged in 1982 when the Government Aircraft Factory’s chief test pilot flew a Shrike against the Australian certification requirement, which as we all know, with the possible exception of the occasional junior lawyer, is that it demonstrate capability to climb with the critical engine inoperative at a one per cent still air gradient in a standard atmosphere, following a takeoff at MTOW.

The test pilot reported that extrapolation of the published data revealed that at 7,150 lb the aircraft failed to meet the requirement by 0.5%. The test flight results showed a worse result. At 6,750 lb the average gradient was 0.85% short of the criteria, and at 7,150 there was a nett deficiency of 1.3%

When told of the performance figures on which the STC was based, Gulfstream American Corporation’s performance engineers didn’t believe the aircraft could be flown to perform 10% better. One of these made two comments:

 “We could sure use a test pilot with that kind of talent,” and

 “If we’d thought it could have performed to a higher weight, we’d have certified it at that weight, sold a lot more airplanes, and made a lot more money.”

The outcomes of the GAF tests are reflected in the following report by consulting aeronautical engineer Malcolm McLeary: “On the information supplied there appear to be three good reasons why a review is warranted:

 The manufacturer has not designed or the State authority of origin has not approved the operation to the higher all up weight figures. The higher weights were unilaterally taken by Australia only.

 The flight tests of an Aero Commander carried out by GAF show non-compliance to the certification standards; and

 The power loading for the type [weight per available horsepower] is suspiciously high when compared to other aircraft supposedly designed to meet the same requirements.”

And further: “Probably worth noting is the fact that if the power available is just sufficient to meet the minimum performance standards with a TOW max of 6,750 lb, the additional power required to meet the same performance standard at a TOW max of 7,150 lb (Australian Certification) is 14.8%. That is to say, for an approximate 10% increase in TOW, the additional power required is about 15%. Arguing further, if the Aero Commander was able to just satisfy the applicable certification standards at the higher TOW of 7400 lb then at 6750 lb the aircraft would need reserve power of approximately 15%. This would indicate that the flight test aircraft had in fact degraded by over 20%, which is unlikely.
The regulator of the day sought to explain the discrepancy between test flight results as the performance differences between a new and a used (3,090 hour) aeroplane. The Gulfstream American Corporation performance engineer rejected the suggestion that the performance of an aircraft that had flown only a little over 3,000 hours could be degraded by 20%: “Well, maybe if it was run over by a bulldozer,” he quipped.

McLeary further commented: “The D.O.A. exists to safeguard the established standards. I believe that they have no option but to reconsider the performance limits of the Aero Commander if written evidence to support the claim is presented. It is a serious enough deviation from the manufacturer’s limits for you to insist on a performance audit, even if it means by-passing the D.O.A. officers and going direct to the Minister.”

A detailed draft of a feature article covering these issues was provided to CASA for comment, and has also been provided to ATSB for its information and assessment. This comment contains its salient points.

CASA, when asked, was unable to cite another single example in which a factory-delivered standard aircraft without aerodynamic or power train modifications, had been certified in this country at a higher MTOW than in its country of certification.

SUMMARY:
Nigel Johnson, a now-retired lifelong GA pilot and senior manager with considerable Shrike Commander experience, comments: “This whole saga is a sad reflection on the competency of government organisations to involve themselves in the more technical aspects of aviation. It has involved three government agencies – an aircraft factory, a bureaucracy set up to guard our coastlines, and the aviation regulator which has changed its name and organisational structure countless times during these events. Almost everything each of these agencies has done during the whole episode, has had the potential to add to aviation’s death toll. No politician of any party has shown any meaningful interest in the complex problems that have been identified, and it seems that even more Shrike Commanders will have to crash before somebody does something about it.

“Although it might mean acknowledging past mistakes, a long-standing CASA aversion, that will need to happen before bureaucratic obstruction and inertia stop killing passengers and pilots.”

Apart from regulatory officials, nobody with whom I have discussed this issue believes that the process by which the STC was issued was a valid one.

Readers are invited to suggest possible conclusions that suggest an alternative explanation other than negligence or deception. I would welcome the opportunity to discuss and if necessary report on any other explanation.

(Edited only to include para breaks. T.W.)

[Wizofoz]

Paul,

Whilst not disputing the facts you present, there is a logic dis-connect between the evidence you produce and the conclusions reached or at least implied in your article.

You argue, persuasively, that the STC to increase the MTOW on the Shrike was not justified on a PERFORMANCE basis.

The accidents in question were due to in-flight failures. Whilst you draw the simple conclusion that more weight= more stress, you do not present any evidence, or even opinion from the manufacturer, that the increased MTOW was in any way related to the in-flight failures.

What evidence do you have that the aircraft, even if they had spent their lives operating at the original MTOW, would not have broken up under the stresses present in these accidents?

[triadic]

Paul,

What you argue is in fact the procedural justification and process for the STC, not that the aircraft is in anyway unsafe.

Do you have any evidence to suggest that the increase in the AUW in Australia has contributed to any in-flight failures?

At this time I do not believe there is any proven link.

The timing of your article was at best inappropriate!

[Atlas Shrugged]

Paul,

Quite simply, IT IS NOT for you, me or anyone else to decide, speculate or make unqualified assumptions on the cause of this or any other accident.

Whether or not you are qualified, leave it to the ATSB and those responsible for the investigation until you have ALL OF THE FACTS, then you can make your comments and perhaps earn back some of your lost credibility.

[Paul Phelan]

I hesitate to enter a dialogue on a forum where I am anonymously accused of dishonesty, opportunism, sensationalism, ignorance of contextual issues, and onanism.

My discussions with the manufacturers’ representatives took place over 25 years ago, so their comments could not be expected to cover issues that had not become evident at that time.

The manufacturer’s representatives expressed surprise at the certification to higher weights, and asked if somebody had fitted “a couple of turbo 350s” for the flight test.

No, there is no evidence that the aircraft would not have broken up if they had been operated at a lighter weight. In fact some of the (about) 30 Shrikes which have now suffered structural failures had probably not been exposed to higher operating weights. Clearly however, higher operating weights increase the risk of a failure incurring . That is one of the two reasons why MTOWs are imposed.

As to whether the type is safe or not, a quote from Mr Swift’s treatise seems relevant. “Things are not always what they seem. Despite the robust appearance, at last count 24 Aero Commanders had lost wings in flight, 35 spars had been found cracked on the ground, and hundreds of other spars had defects caused by fatigue, corrosion, stress corrosion and static overload.” Obviously frustrated by inaction on the issue, Mr Swift exclaimed: “How was it that such fundamental structural problems were still unresolved after forty years?”

That was written in 1995. I do not understand why anybody who is interested in this issue doesn’t keep a copy of Mr Swift’s study in their office.

I have not identified a single pilot who believes that an unmodified factory standard Shrike was ever able to demonstrate a 1% engine-out climb under the certification conditions at any weight in excess of 6,750 lb. I once tried it at 6,750 and the outcome was fully consistent with the results reported by the GAF chief test pilot.

Pilots who are much more familiar with the type than I am assure me that the average airframe hours on the Shrike fleet are in the order of 25,000. This would be partly explained by their use on coastwatch and night freight operations.

As for “appropriateness”, this is a live issue which has been ignored by responsible people for a long time.

I don't plan to continue debate on this forum. If anybody wants to communicate on relevant issues my e-mail is [email protected]

(Edited only to include para breaks. T.W.)

[Captain Nomad]

Paul's research has raised some interesting questions though...

Operationally speaking it is a good thing that the type has not had a spate of engine failures in IMC. I wonder how many pilots flying the machine IFR actually recalculate their approach minima's to a height that would guarantee obstacle clearance based on what can only be argued as increadibly poor single engine climb performance? The figures suggested for the type fall way short of the 100' clearance @ 2.5% which the charts are based on... :hmm:

[Diatryma]

Most people who regularly read newspapers understand that it’s not journalists, but subeditors, who write the headlines.


Really? Is there a survey of readers which shows this to be the case? Or is this just another assumption on your part?

Whether it's you or subeditors who write the headlines, this particular one is a disgrace. It reflects badly on you and your paper.

I believe your paper should issue an unreserved apology to the grieving families and friends of those who perished in both accidents. It's the right thing to do - and probably wise!

Di :yuk:

[Wizofoz]

Paul,

First up, thanks for having the cohonas to defend yourself publically- not many journalists do.

No, there is no evidence that the aircraft would not have broken up if they had been operated at a lighter weight.

Why, then, was this the clear implication of your acticle?

Clearly however, higher operating weights increase the risk of a failure incurring . That is one of the two reasons why MTOWs are imposed.


But there is no evidense that this was the reason or even a factor in these accidents. The original MTOW was imposed for the OTHER of the two reasons, performance. Indeed you note that there have been quite a number of in-flight break-ups of aircraft opperated to the original MTOW.

As the headline of the article is clearly misleading, and your name is on the by-line, have you asked the newspaper to print a retraction?

[triadic]

There are clearly two issues in this discussion:
(1) the increased Australian TOW, and
(2) the known problems with the wing.

The known spar issues have no proven association whatsoever to do with the increased TOW applied in the Australian STC.

Some investigation, would to me, indicate that the known problems with the spar relate to the "inner" wing - ie: inboard of the engines. Both of the failures in Australia were, I understand, in the outer wing.

I agree with the previous two posts, an apology in the Australian would be the right thing to do. And the sub-editor should butt out of what he obviously knows nothing about.

I have not identified a single pilot who believes that an unmodified factory standard Shrike was ever able to demonstrate a 1% engine-out climb under the certification conditions at any weight in excess of 6,750 lb.

Crap – Look harder! I recall a number of the Exec pilots acted as observers on test flights back in the early 70's and the Shrike at 7150lb made the required climb at 5000ft. There were others around at the time that would verify that also. The VFR requirement I recall was to maintain height at 7400lb - it did that also.

I hesitate to enter a dialogue on a forum where I am anonymously accused of dishonesty, opportunism, sensationalism, ignorance of contextual issues, and onanism.

Paul, it is good to see you here, however get your facts right, publish at an appropriate time with due consideration for factors at the time and perhaps this dialogue would not occur.

I don't plan to continue debate on this forum.

Your call. And I say again, it is good to see you post here. But just like our mate Dick has found, to ignore this type of discussion only makes it worse - for yourself as a industry advocate and the credibility of both you the journals you write for. You should be well aware after many years writing about aviation matters that when you fail to get it right, you can always expect some flak!

In this case it is well deserved!

[Sunfish]

Without wishing to comment on the actual case, whose details I do not know, nor do I know the slightest thing about Shrikes.

The known spar issues have no proven association whatsoever to do with the increased TOW applied in the Australian STC.


But with my engineers hat on, I have to say this is not the truth, the whole truth and only the truth because such a relationship certainly exists in theory.

The fatigue life of a chunk of Aluminium alloy is a function of its entire stress history from new. That is the integral of load applied times length of time applied.

In addition, as loads increase, so does sensitivity to stress corrosion and cracking at stress raisers caused by allowable manufacturing defects.

The "Hard Time" limits prescribed for the replacement of certain parts after a certain number of hours or cycles is predicated on the expected loading of that part. Change the loading conditions and the part may last a lot shorter time before failure.

This is an inexact science, as the continual stream of SB's and AD's even for Boeing's finest attests.

IF (and its a big if) structural failure was a factor in this terrible accident, then it will not be the first time that a well maintained and professionally flown aircraft has fallen victim to the aircrafts previous history.

[john_tullamarine]

There are a few suggestions in this thread which are a bit wide of the mark.

I note that I missed Paul's original article so I offer no comments specifically directed towards it.

The Commanders have a known set of problems which the TC holder and regulators set out to address via SBs, ADs, etc ... just like every other Type

Some general thoughts from the depths of the memory cells only -

(a) the then FAA requirement (if you wish you can review it on the FAA website's historical rules) for OEI climb differed to what the ANO required. The relevant Australian operator sought to utilise that difference to gain some extra weight and that sort of thing has been done for various aircraft over the years. My recollection is that the justification was based on structural detail comparison with larger models within the range with any non-conservative differences being addressed by mod - eg, the 500A, with which I had some involvement, had to have uprated wheels/brakes as best I recall. Models involved had to demonstrate the climb capability to justify certification aspects of the proposed weight delta.

(b) generalised references to aircraft being overweight are "correct" only to the extent that the Australian permissible MTOW exceeded the US figure. However, it must be understood that such "excess" weight was perfectly legitimate and authorised by the Australian AFM. It is very important to keep in mind that the then rules permitted local recertifications. Many were done and all required the appropriate level of tap-dancing ... DCA et seq certification folk were never amenable to being hoodwinked. When we are talking about the period and performance we are looking at eminently fine chaps such as Tenenbaum, Fincher, et al. All highly principled (sometimes to the point of being a pain in the neck). That doesn't suggest that mistakes were never made .. but the attitude and general attention to detail was always there. To suggest that the Oz regulator engineering folk were other than first rate is not supported by history regardless of what popular perception may be or have been.

(c) He was also very much aware of the fatigue issues ... Notty and I have discussed various structure cracks over the years .. he was very aware of such problems and always appeared conservative in his attitude. However, as Steve indicates in his paper, the very nature of inspection aspects of fatigue is tied up with inspectability ... ie it's a bit of a mongrel beast ..

(d) There has never been to my knowledge any meaningful flight testing done at the higher (VFR) takeoff weight 3357kg or at the higher IFR wt of 3243kg .. It would be useful for the writer to check his facts with CASA airworthiness. The basis for the Oz weights were the climb tests.

(e) the coastwatch contract .. came much later. If I recall correctly, the earlier Shrikes were used for the Navy target towing contract ? I recall a colleague relating a tale wherein the towing to simulated attack run evolution got a bit out of synch with the target retrieval ... something about the target filling up with water ...

(f) Also this category of aircraft is only required to maintain 5000' on one engine at ISA conditions. Not indicative of the aussie environment. .. misses the point. The certification requirement only puts a line in the sand. It is up to the operator's policy as to whether any further conservatism ought to be incorporated into routine operations.

(g) In June 1991, seventeen senior engineers met in Seattle . The linked paper is well worth a read for general education. Be assured that Steve Swift and Alan Emmerson, both with the Regulator and fine chaps, were very soundly versed in structural fatigue matters.

(h) The Department of Aviation never made available any flight test data or structural analysis to support the higher STC weights. .. but the data exists .. it was used to broker the subsequent 500A work. One needs to keep in mind that the Regulator has always taken the proprietary rights interests of certification data pretty seriously.

(i) The weights were challenged in 1982 when the Government Aircraft Factory’s chief test pilot . I don't recall this episode nor have I seen any related data. However, one needs to be careful that one matches the appropriate standards against the performance ? 101.22 went through several revisions (as I recall to suit some problems with which the Nomad presented). The 500S work was done to the earlier (and simpler) requirements. It is not at all inconceivable that the stated GAF tests were done to one of the later revisions ? (Note - I am not anti-Nomad, in fact quite the opposite, having worked on the beast during two separate periods).

(j) The higher weights were unilaterally taken by Australia only. ... as was quite right and proper under the regs of the time. It is only since the later regs came in that the local regulator has been tied to the NAA requirements.

(k) Probably worth noting is the fact that if the power available is just sufficient to meet the minimum performance standards with a TOW max of 6,750 lb, the additional power required to meet the same performance standard at a TOW max of 7,150 lb (Australian Certification) is 14.8% .. sounds like arrant nonsense to me. The two certification requirements were quite different.

(l) It is a serious enough deviation from the manufacturer’s limits for you to insist on a performance audit, even if it means by-passing the D.O.A. officers and going direct to the Minister. Having worked over the years with these officers may I assure readers that they were never pushovers when it came to demonstrating certification compliance. On the contrary, there are numerous instances of FOT certifications where the local regulator required additional performance tests .. the Rockwell Commander singles come to mind as an instance ..

(m) The manufacturer’s representatives expressed surprise at the certification to higher weights, and asked if somebody had fitted “a couple of turbo 350s” for the flight test. Only speculation but this comment only makes sense in terms of considering a recertification to the original requirement, not a different one ...

(n) I have not identified a single pilot who believes that an unmodified factory standard Shrike was ever able to demonstrate a 1% engine-out climb under the certification conditions at any weight in excess of 6,750 lb. .. apologies but I have so flown. The secret, of course, is that one has to define WHICH certification standard is subject to test ... certainly, the higher Oz weights could be flown to the then Oz requirement.

(o) I wonder how many pilots flying the machine IFR actually recalculate their approach minima's to a height that would guarantee obstacle clearance based on what can only be argued as increadibly poor single engine climb performance?[/i] ... you mean like most other light twins of similar certification basis ?

(p) [i]single engine climb exercise, please divulge how exactly you set zero thrust ... not relevant .. OEI tests are done shutdown and feathered.

[Justin Grogan]

:hmm:
Seen some feathered propellers in my time but never a feathered engine!

[LeadSled]

Folks,

To add a little fuel to the fire!

Are the increased gross weight any longer valid, an STC to an airworthiness standard that has been repealed, and an Australian AFM that is no longer valid.

This came up when C-47, VH-EDC went swimming in Botany Bay some years ago. The pilot was accused of operating over MTOW, base on the old Australian AFM weights, (26,200lb, as I recall, the end result of an industrial dispute) but the pilot was entitled to operate the aircraft to the FAA AFM, which specified (in this case) a higher weight.

My best guess is that the T-C AFM limitations now apply to Aero Commanders--- comments --- unless CASA has produced a concession to continue operations at the "Australian" weights.

There must have been some structural justification of the higher weight, as I recall a spar strap was required, and the existing Australian spar strap was an acceptable means of compliance when an FAA AD for a spar strap appeared on the scene.

Tootle pip!

[Pentacle]

I note that I missed Paul's original article so I offer no comments specifically directed towards it.

John, excellent post. For your information, Paul Phelan's article is still available online (http://www.theaustralian.news.com.au/story/0,,22216475-23349,00.html) (in The Australian).

[tail wheel]

Following article courtesy of The Australian:

Crashed Shrikes were overweight

Paul Phelan | August 10, 2007

GOVERNMENT officials were warned 25 years ago that Shrike Commander aircraft like the one that crashed near Melbourne on July 31 were allowed to fly at weights 10 per cent higher than they were designed for.

At least 25 Aero Commanders worldwide have disintegrated in flight, another having crashed fatally in Tasmania in February 2004 when a wing separated.

Flying at heavier weights increases the risk of structural failure, and the deadly mix of turbulence and latent fatigue can trigger in-flight break-up.
In the US, their country of origin, Shrikes are limited to a 3062kg maximum takeoff weight, but when they were imported here as used aircraft, the (then) Department of Aviation issued a "supplemental type certificate" allowing them to fly at up to 3357kg, the equivalent of three extra passengers.

Though CASA insists that test flights were carried out to prove the aircraft's capabilities, performance engineers from Gulfstream American Corporation, its manufacturer told Australian operators the assessment must be wrong.

"If we thought it would fly 10 per cent heavier, we'd have certified it at that weight, sold a lot more planes, and made a lot more money," said a Gulfstream engineer. The decision created such dismay at the Government Aircraft Factory, which was building competing aircraft, that its management hired a Shrike Commander and its chief test pilot flew a series of test flights to evaluate its engine-out performance against certification requirements.

Though aircraft in this category must show they can maintain a 1 per cent climb gradient with one engine shut down, tests showed it didn't quite meet the requirement even at the US-certified weight, and it couldn't even maintain height on one engine at the higher weights approved in Australia.

Consulting aeronautical engineer Malcolm McLeary supported calls for a review, saying there appeared to be three good reasons why it was warranted: "The manufacturer has not designed or the state authority of origin has not approved the operation to the higher all up weight figures. The higher weights were unilaterally taken by Australia only. The flight tests of an Aero Commander carried out by GAF show non-compliance to the certification standards. And the power loading for the type (weight per available horsepower) is suspiciously high when compared with other aircraft supposedly designed to meet the same requirements."

Mr McLeary said that to carry the extra weight safely, the Shrike would have needed at least 15 per cent more horsepower than it had. He also scoffed at the DoA's suggestion that the GAF test aircraft's performance was due to age: "This would indicate that the flight test aircraft had in fact degraded by over 20 per cent, which is unlikely."

The Gulfstream engineer agreed that the performance of an aircraft that had flown only a little over 3000 hours could be degraded by 20 per cent: "Well, maybe if it was run over by a bulldozer," he quipped.

CASA engineer C. S. Swift, when he published a detailed study of the Shrike's woes, exclaimed: "How was it that such fundamental structural problems were still unresolved after 40 years?"

But 12 years later, about 50 Shrike Commanders are still flying in Australia. More than half are registered to General Aviation Maintenance Pty Ltd, the operators of the crashed plane, and they are still certified to fly here at a 10 per cent heavier MTOW than the US regulator allows.

The Shrike remains popular with commercial operators because of the weight concession, but its pilots are now worried that the average aircraft in Australia has flown about 25,000 hours at unusually heavy weights.

---------------------------------------

Without commenting on the veracity of the article it is worthy to note the article states:
GOVERNMENT officials were warned 25 years ago that Shrike Commander aircraft like the one that crashed near Melbourne on July 31 were allowed to fly at weights 10 per cent higher than they were designed for. (my bold Italics).

That statement appears to be confirmed by this CASA pdf document (http://www.casa.gov.au/airworth/papers/AeroCommander.pdf) and does not attribute the recent Shrike accident in Victoria to the Australian DCA/CASA approved higher gross weight for the Shrike.

Tail Wheel

[Andy_RR]

But with my engineers hat on...

...The fatigue life of a chunk of Aluminium alloy is a function of its entire stress history from new. That is the integral of load applied times length of time applied.


Perhaps you should rephrase or hand your engineer's hat back in Sunfish. Fatigue strength is more about stress cycles and less about static load.

If the Shrike really was designed to run at the ragged edge of fatigue strength design factors such that a 10% MTOW increase would push it over the edge, then surely it would have been fitted with some kind of fatigue index device, a la Bulldogs etc?

A

[Diatryma]

Parallels may end riddle

Article from: The Sunday Tasmanian

MICHAEL STEDMAN
August 19, 2007 12:00am

THE Civil Aviation Safety Authority has confirmed it is looking into alarming similarities between a plane crash that killed two in Victoria last month and an accident near Hobart in 2004.

Millionaire aviation businessman Steve Nott and young pilot Janelle Johnston died when their twin-engined Aero Commander 500 went down near Clonbinane in Victoria on July 31.

Striking similarities have emerged with the death of 21-year-old-pilot Heather Cochrane who was the sole occupant of an identical plane that crashed in fine weather on the way from Hobart to Devonport in 2004.
The Australian Transport Safety Bureau, which is investigating the crash, has noted "intriguing parallels" between the two accidents.

It is hoped the new investigation may provide answers about what caused the 2004 tragedy -- the exact cause of which remains a mystery.
Wreckage was scattered over 1300m in the 2004 crash "consistent with the aircraft having sustained an in-flight structural failure of both wings and the tailplane," the ATSB report said.

Early accounts of the Victorian accident are that the plane sustained massive damage in mid-air -- with both wings and its tail torn off.
The tail section was found 700m from the fuselage.

CASA spokesman Peter Gibson said it had contacted the operators of 65 registered Aero Commanders around the country to see if they had had problems with their planes.

Five Aero Commanders are registered in Tasmania.

But Mr Gibson said, at this stage, there was no need to ground the fleet -- most of which were more than 30 years old. "We are aware of the similarities (between the accidents) but we need evidence of a real problem and at this stage we don't have that," Mr Gibson said.
Operators too are not worried about the safety of the planes, which are often described as the "workhorses of the sky".

Tasmanian Aero Club manager Joe Miller said he and his pilots had no concerns about flying their Aero Commanders, which is the sister aircraft to the one that went down in 2004.

"They are built like a brick ****house and we have not had any problems with wing fatigue or structural problems since we started operating them here," he said.

But Aero Commanders have had a long history of in-flight accidents.
A paper prepared by CASA principal fatigue engineer S. Swift in 1995 highlighted 24 cases where Aero Commanders had lost wings in flight, and 35 others where serious cracks had been found.

CASA said problems with wing fatigue and cracking had been addressed in ageing aircraft maintenance directives and through ongoing inspections.
ATSB deputy director aviation safety and investigation Julian Walsh said early evidence from the Victorian crash was that the maintenance regime had been adhered to.

He said investigators were looking for anything that linked the latest crash with the Tasmanian accident.

"There is no doubt there are some intriguing parallels between the two and, as the investigation develops, that will be something we will be particularly interested in," Mr Walsh said.

He said the weather on the night of the accident, which included severe wind gusts of up to 80km/h, was of "significant interest".
They will also look closely at the auto-pilot, which was identified as a possible factor in the Tasmanian crash.

Tasmanian independent aviation consultant Brian Morgan, who investigated the 2004 accident for charter operator Tasair, said two similar accidents were not proof of an inherent problem.

"Aero Commanders are one of my favourite aeroplanes to fly -- they are wonderful aeroplanes, very stable and very easy to fly," Mr Morgan said.
"Both aircraft appear to have suffered structural failures in the air but, whether that is due to inherent problems of the aircraft or entirely different circumstances, we may never know."

A preliminary report into the Victorian accident is likely to be released by the end of the month.


THIS is a bit more of a professional effort from a journalist!

Di :ok:

[bushy]

Would there have been further investigations into these two accidents if Paul had not written his article?
Those who say "leave it to ATSB" or "Leave these things to CASA" should read the Coroner's report on the Lockhart River crash. In a report that many say is "too forgiving" the Coroner criticises the aparent agressive disagreements between ATSB and CASA.
Thank god they are both watching each other. This is much better than it was when they were all the one happy family and no-one was watching. Pilots and operators were not game to criticise, as they all had renewals coming up, or approvals, dispensations etc to get or renew.
But it appears that this may be affecting the integrity of their reports now, and the Coroner discounted some of their findings. We cannot just say "leave it to the ATSB" although their reports usually contain valuable information.
It appears that Australia's Shrikes did have approval to fly in Australia at weights much greater than the maker or the FAA approved, and many (if not all) probably did it many times.
I wonder why this approval was given "only in Australia".

[novicef]

CASA spokesman Peter Gibson said it had contacted the operators of 65 registered Aero Commanders around the country to see if they had had problems with their planes.

Five Aero Commanders are registered in Tasmania.

But Mr Gibson said, at this stage, there was no need to ground the fleet -- most of which were more than 30 years old. "We are aware of the similarities (between the accidents) but we need evidence of a real problem and at this stage we don't have that," Mr Gibson said.
Operators too are not worried about the safety of the planes, which are often described as the "workhorses of the sky".

Tasmanian Aero Club manager Joe Miller said he and his pilots had no concerns about flying their Aero Commanders, which is the sister aircraft to the one that went down in 2004.

So what sort of response did Peter Gibson expect from the operators?

Tasmanian Aero Club manager Joe Miller said he and his pilots had no concerns about flying their Aero Commanders, which is the sister aircraft to the one that went down in 2004.

"They are built like a brick ****house and we have not had any problems with wing fatigue or structural problems since we started operating them here," he said.

So succinctly put, a true GA manager.

Was the increase in MTOW requested to obtain an advantage in order to obtain a contract? The fact is that a number of these aircraft have broken up mid flight should question the wisdom of such an approval.

In the US, their country of origin, Shrikes are limited to a 3062kg maximum takeoff weight, but when they were imported here as used aircraft, the (then) Department of Aviation issued a "supplemental type certificate" allowing them to fly at up to 3357kg, the equivalent of three extra passengers.

Though CASA insists that test flights were carried out to prove the aircraft's capabilities, performance engineers from Gulfstream American Corporation, its manufacturer told Australian operators the assessment must be wrong.

"If we thought it would fly 10 per cent heavier, we'd have certified it at that weight, sold a lot more planes, and made a lot more money," said a Gulfstream engineer.

As the man said if they could have certified the aircraft at a higher weight they would have. CASA should seriously look at these and the other old, old aircraft like the PA31, C402 etc who have been around 30 years or more as to their continued viability (SAFETY).

If the ATO disallowed well off individuals to claim tax breaks when operating an aircraft or charter company at a loss, the number of shady operators would be reduced. At the end of the day it’s all about money and knowing the right people. By that I am not implying the company concerned is shady but there are a number who would fit the bill.

Paul keep going with this, do not allow individuals with vested interests deter your reporting. It’s only individuals like you who bring incidents like this to the fore. Regardless of how well respected the owner of the company was or how knowledgeable on Shrikes he was, to my knowledge he was a LAME not a stress engineer a big difference. Perhaps you should frequent this forum more often and highlight through research the problems that GA has.

[Diatryma]

Would there have been further investigations into these two accidents if Paul had not written his article?



I really don't think CASA were waiting for some journo to write an article before deciding whether or not to conduct further investigations. The similiarities were fairly obvious - even to me!



It’s only individuals like you who bring incidents like this to the fore.


Oh for crying out loud!



What is the world coming to if believe we need to rely on the journalist profession to direct aviation safety in Australia.

The fact that these sort of comments are being expressed on PPRuNe is a sad indictment of CASA.

Di:sad:

[Walrus 7]

Yes, this is a sad indictment of CASA. Every now and then they need a bit of a clout to be reminded they are here to serve us not control us. When journos stop stirring the pot so vigorously that the regulators are embarrassed into a move, then democracy is in real trouble! I don't really think that Paul's article has forced CASA's hand. Remember CASA don't do crash investigation. There would have been an ATSB investigation anyway. Whether or not CASA acts on the recommendations is another question.

Paul Phelan has been accused of CASA-bashing in the past and his "Backlash" column in Australian Flyinghas copped its fair share of criticism. However, Paul's research is usually second to none in the industry and he's never taken a backward step. This is what we need more than anything: someone who's prepared to write their name to considered comment and thumb their nose at the regulators on our behalf.

As a GA scribbler myself, some of my work has also been changed by subs to something that was not intended. It is infuriating, but there's nothing that can be done about it. The subs and editors have the final say; we with the bylines get the public thumping. That's the industry!

Walrus
Disclaimer: Walrus has had work published by AF in the past and has had intermittent contact with Paul Phelan over the past three years or so. This post was edited to remove an embarrassing typo before anyone saw it.

[equal]

someone help me here, why is VH-YJB mentioned in the article by mr phelan?

this particular aircraft was registered feb 2007 and had recently been brought over by G.A.M. from the states, is it safe to assume this aircraft had been adhering to the FAA MTOW for it`s previous life?

if so then this particular aircraft and accident doesn`t belong anywhere near the overweight shrike debate.

[Jabawocky]

Maybe not, but its brothers and sisters seem to have a history or serious cracks, and maybe this one has not been as carefully checked as others.....who knows:uhoh:.

Will have to see what the ATSB find, either way it seems the extra weight is not the only factor, and all it may do is accelerate the cracking.

I do think the earlier comment about if the manufacturer felt it was capable of it and they would have tested and had it certified, they would have done so and sold more aircraft as a result, was quite relevant.

J

[gaunty]

As thinking people and passionate about our craft Mr Phelan and I don't always see eye to eye, but whether I agree with him or not I do respect his views.

He is absolutely spot on in regard to this subject.

"If we thought it would fly 10 per cent heavier, we'd have certified it at that weight, sold a lot more planes, and made a lot more money," said a Gulfstream engineer. is game set and match, thank you umpires, thank you ball boys.

I hope someone who was around then can help me out with my increasingly cranky memory but I have an recollection?? that the increased GW was a result of the then DCA who had ordered a swag of the 680E?? for "liason" finding that this fine aircraft did not quite come up to "Australian" expectations. Simple really as the certifying authority you simply change the rules to make em fit. There is no other rational explanation.

In any event the "history" of the type is not exactly news and I have wept on more than one occasion when I hear the young tyro (younger even than the aircraft) proclaim,.............. exultantly even.................."I'd fly her to hell and back, she's built like a brick one mate". :ugh::ugh::ugh::{

[triadic]

Gaunty, we have partly to disagree on this one.

Whilst Paul has been writing about aviation matters for some time, and I always like to see what he has to say, on this occasion he got it wrong and to top matters off he had a rogue sub-editor and the timing was disgusting.

He is absolutely spot on in regard to this subject.

Quote:
"If we thought it would fly 10 per cent heavier, we'd have certified it at that weight, sold a lot more planes, and made a lot more money," said a Gulfstream engineer.
is game set and match, thank you umpires, thank you ball boys.

Only on the assumption that the quote from the engineer was correct and that he was indeed representing the manufacturer (??) My understanding is that much of the work carried out on the model 500 in Australia was known to the manufacturer and in at least some areas supported and perhaps 'admired'.

The STC for the increase in gross weight was undertaken by an organisation in Melbourne that did all the structural justification and the appropriate test flying and as mentioned in previous posts, it met the requirement of the day to suit the regulator.

It had nothing whatsoever to do with the DCA Aero Commanders. To my knowledge, DCA never owned a Shrike. And yes, those early 560/680 models were not so brilliant performers.

If my memory serves me correctly much of the justification for the IGW was the result of the difference between the 'Normal' and 'Utility' category (as per FAA guidelines). Again if my memory serves me correctly the structural justification for the model 500S/U was up to around 7800lb on that basis.
That would give some margin above the 7150lb for IFR ops that the STC permitted when approved.

To date there is no proven link between the Australian STC and either of the in flight failures in this country. And as I said in a previous post, the failures in Australia were I understand in the outer wing, whereas the known problem areas were the inner wing. YJB had less than 5000hrs and had not been in the country for that long, so to assume that the IGW STC was a factor is nothing other than a wild guess.

I am sure the ATSB are very much aware of these issues and they will obviously investigate these apparent ‘links’ as part of their investigations. Obviously CASA will take an interest in the proceedings. At this time there is no link, and we will all have to wait for the experts to deliberate.


Jabawocky

Maybe not, but its brothers and sisters seem to have a history or serious cracks, and maybe this one has not been as carefully checked as others...

I bet it was, as were all the imports by that company.

But Mr Gibson said, at this stage, there was no need to ground the fleet -- most of which were more than 30 years old. "We are aware of the similarities (between the accidents) but we need evidence of a real problem and at this stage we don't have that," Mr Gibson said.

For once I agree with him!