CAO 20.7.1B First segment

[BorisAndDoris]

For a turbine twin in the first segment 20.7.1b calls for positive gradient. If the runway has a .2% slope up, does that mean the first segment must actually be .2% to be considered as positive? If the runway slopes .2%down slope would a descending (relative to absolute altitude but not to the ground) flight path of -.1% be considered positive?

[WannaBeBiggles]

My take on it is you can take it as "not negative" so you'll need to be able to stay in ground effect while accelerating to your climb speed while in the takeoff configuration with the critical engine inoperative.

[FGD135]

No, the slope of the runway is not relevant.

[john_tullamarine]

The WAT limit requirements are for still air and in isolation to other considerations - the relevant bit of 20.7.1B specifically cites no ground effect for the first segment. That is to say, WAT limits are just lines in the sand to give the aircraft an absolute basic level of performance so that we don't have to rely too much on the curvature of the earth ...

If you have an aircraft with a poor first segment then it is sensible risk management to keep the first segment not less than an upslope runway for obvious reasons.

When does the first segment present a problem ? - ie when are you likely to be through screen before the gear has had time to retract ? -

(a) when the performance is comparatively high - low gross weight, low Hp, low OAT. Conversely, for most aircraft, high gross, high Hp, high OAT and you generally don't see a first segment as the gear is up prior to screen. That is, for most aircraft, the runway slope isn't going to present too much of a concern.

(b) high wing, physically large aircraft with nacelle mounted gear which takes forever to retract. A good example is the AW650 Argosy (remember IPEC Aviation ?). The good old Queen of the Skies ALWAYS had a first segment for EVERY takeoff. For such aircraft, first segment is something to consider due to its not inconsiderable length over the runway.

Going back a little while, I looked after IPEC's performance on the AW650 and DC9. For the Argosy, we took a management decision and made it policy to limit the RTOW to achieve not less than runway upslope for the first segment. Lost a few kilos but everyone slept a little more peacefully at night ...

[dodo whirlygig]

No, the slope of the runway is not relevant.

Agree.

Simply - a positive gradient is when the altimeter is increasing .

[rodney rude]

Dodo - if the runway is sloping up, your altimeter will rise, even though you are still on the ground. The gradient must start at 35ft above the ground.

Once you lift off, a gradient is distance forward vs distance up. Nothing to do with the way the ground slopes. If the ground slopes down after you lift off, goodo, you are safer. But a positive gradient is a distance you climb reference MSL (ie a rising altimeter meaning a pressure drop due altitude rising) versus the distance forward it takes to climb.

[dodo whirlygig]

Dodo - if the runway is sloping up, your altimeter will rise, even though you are still on the ground.

However, the first segment doesn't apply whilst you are on the ground so that comment is irrelevant.

Once you lift off, a gradient is distance forward vs distance up.

In other words, the altimeter is increasing.

ie a rising altimeter

Isn't that the same as "the altimeter is increasing"?

[FGD135]

Most of the time, you won't be over the runway during the first segment, but over the ground beyond the end of the runway (stopway/clearway, splays), so the question is almost entirely moot.

[BorisAndDoris]

Hi John.
We have an aircraft which broadly resembles the Argosy in your description, and is normally first segment limited - and retraction is normally only complete at 300ft.

[BorisAndDoris]

But if your engine fails at V1 on the runway and your "positive climb" is 0.1% and the runway is sloping up at 0.2%, you cannot get airborne.
Our aircraft is similar in general description to John's Argosy and is first segment limited, and in a normal takeoff gear retraction is only complete by 300ft.

[john_tullamarine]

retraction is normally only complete at 300ft

Now that's an interesting one. Perhaps you can PM me with details for an off line discussion ?

One needs to keep in mind that first segment (and all the segments) is relevant OEI only. As a general rule, we ensure that the AEO profile is above the OEI profile and all's well.

"positive climb" is 0.1% and the runway is sloping up at 0.2%, you cannot get airborne.

Probably not quite that problematic but it's good to see your operator is mindful of the consideration

[BorisAndDoris]

PM'ed John

[FGD135]

But if your engine fails at V1 on the runway and your "positive climb" is 0.1% and the runway is sloping up at 0.2%, you cannot get airborne.
Not quite right. The first segment starts at a point known as "reference zero", which is at 35' above the runway and where the takeoff is deemed to have ended - it does not start on the runway.

If the TODA for the runway was greater than or equal to the TODR from your performance calculations, then you are "guaranteed" to get airborne, having lost an engine at V1, and be at 35' before the start of the (rising) obstacle surface at the end of the clearway. This is the point where the first segment starts.

But from there on, there is no guarantee you won't collide with obstacles. It all depends on your first and second segment performance and the slope of the obstacle surfaces over which you are flying.

[Rudder Sir]

Sounds like this is just a reproduction of FAR25 (or equivalent) certification requirements, in which case the first segment commences at the END of the takeoff procedure (i.e. 35 feet dry/15 feet wet above the departure end of the runway), and is essentially just a requirement that the aircraft doesn't sink while the gear retracts. Runway slope is a factor for takeoff, but not climb. Obstacles in the departure splay must of course be taken into account, but this has nothing to do with runway slope.

[john_tullamarine]

If the TODA for the runway was greater than or equal to the TODR from your performance calculations, then you are "guaranteed" to get airborne,

Depending on the rules applicable to the certification, TODR will have up to half or two thirds the airborne distance to screen beyond the end TORR. This is to give you some comfort that the aircraft should be airborne by the end of TORR. Guarantee ? pretty likely but prefer not to figure in guarantees ...

before the start of the (rising) obstacle surface at the end of the clearway.

No warranty that the clearway won't have some slope associated with it ...

It all depends on your first and second segment performance and the slope of the obstacle surfaces over which you are flying.

Which is why it is prudent to consider first segment gradient and ground slope in the relevant part of the takeoff.

Sounds like this is just a reproduction of FAR25

Pretty much the case. 20.7.1B originally was the operational recasting of the Australian certification requirements. ANO 100.5 reflected the BCAR while 100.6 FAR 25 - both now well and truly binned post Ron Yeats' involvement.

and is essentially just a requirement that the aircraft doesn't sink while the gear retracts.

That's the certification line in the sand.

Runway slope is a factor for takeoff, but not climb. Obstacles in the departure splay must of course be taken into account, but this has nothing to do with runway slope.

As a general consideration, that is a reasonable position. However, for those aircraft which have an abysmal first segment performance, takeoff over rising ground (doesn't matter whether it is the runway or beyond the runway head) warrants some risk management going a little bit beyond just applying the AFM requirements.

[Rudder Sir]

Thanks John for the clarifications and summary. I absolutely agree with your point about risk management, although I'd emphasis (as you've alluded to) that minimum regulatory requirements should not form the sole basis for operational risk management - particularly the more prescriptive style rules of which you still seem to have a few in Australia (although, pleasingly, CASA is slowly learning about performance-based oversight/regulation from their good friends across the ditch :}). There will likely be some other rule requirement that a multi-engine aircraft on revenue passenger operations must 'clear all obstacles in the takeoff flightpath' after suffering a failure of the most critical engine at the most critical point, and that's probably the catch for this particular issue I'd think.

[Xeptu]

I'll just quote it as I remember it without refreshing my memory. The first segment for a two engined aircraft must be positive (there is no minimum climb gradient) from airborne until the gear is retracted. The certification requirement for subject aircraft types the gear must be fully retracted within 12 seconds.

[john_tullamarine]

Just a minor observation .. The first segment for a twin-engined aircraft must be positive (there is no minimum climb gradient) from airborne until the gear is retracted

True, regarding the gradient. However, the first segment, proper (if it exists at all), commences from screen and continues until the gear retraction is completed. Again, minimum WAT gradient is zero.

[machtuk]

I always enjoy the discussions that pop up every now & then about climb grad etc; makes for interesting reading, glad we don't have crashes every day though!:-)

[BorisAndDoris]

All well and good stating that first segment starts at 35ft - but you must get there first.
Your TODR gets you from on the runway to that 35ft point, and the transition from "on the runway" to "35ft" must be at your first segment performance.
So surely that means you must be able to climb at first segment requirement with the runway slope factored in to achieve TODR? Do you have to refer to the First Segment with runway slope factored in to calculate an initial TOW, before only then using that weight to calculate TODR,ASDR?

[john_tullamarine]

and the transition from "on the runway" to "35ft" must be at your first segment performance.

Not quite the case. (Caveat - I don't know your particular aeroplane's numbers so my comment is only generic). In general, the flare from lift off to screen will be associated with an acceleration to V2 (OEI) or, probably, a bit more (AEO). Further, the gear, initially, will be down, and then commences retraction.

So surely that means you must be able to climb at first segment requirement with the runway slope factored in to achieve TODR?

Again, not quite. The TOD calculations will include consideration of slope (see, for instance https://www.ecfr.gov/cgi-bin/text-idx?SID=1aa662955a4552969989badda36d3b9b&mc=true&node=se14.1.25_1105&rgn=div8 for the current FAR 25 requirements). Clearly, if slope presents a problem, the weight gets reduced in the AFM to suit the aircraft's capabilities.

Do you have to refer to the First Segment with runway slope factored in to calculate an initial TOW, before only then using that weight to calculate TODR,ASDR?

Not at all. Each of the various limits to be considered can be examined in isolation (albeit that some AFM presentations lump multiple limits into the one chart - eg X-D charts), TODR (OEI/AEO) give maximum weights, first (and the other) segments give other weights, and so on for all the other limits to be considered. After boring ourselves silly with a bunch of different calculations, whichever result gives the lowest weight on the day becomes the limiting RTOW figure for that combination of input variables.

[rodney rude]

Dodo you've missed my point.

When I said if a runway slopes up your altimeter will be rising you have come back and said, correctly, that the first segment doesnt start on the ground, therefore my comment is irrelevant. My comment was based on yours where you said "simply, a positive gradient is where your altimeter is increasing." My comment is not irrelevant, an increasing altimeter on a sloping runway does not constitute a positive gradient for a segmented climb.

[FGD135]

... the transition from "on the runway" to "35ft" must be at your first segment performance.Incorrect, as JT has pointed out. The "getting to 35 ft" stage is considered part of the takeoff - where the gear is still down. The TODR from your performance calculations includes the distance where you are airborne and staggering up to 35 ft.

First segment starts from 35 ft. Second segment starts from when configuration change (e.g. gear retraction) is complete.

[machtuk]

I can't believe that a few here are over thinking this! Crying out loud after 40 years oddly enough I'm still here despite 20.7.1B!

The basic segments are laid out, we can't change the % of climb in any plane above 5.7 T, every day we launch it's different, just get on with it & fly the bloody thing!

[john_tullamarine]

The "getting to 35 ft" stage is considered part of the takeoff - where the gear is still down

Minor observation. Gear will be selected up sometime during the flare to screen as determined during the FT program and declared in the AFM. If the retraction sequence is completed by screen, there is no first segment, otherwise the final bits of retraction occur during the first segment.

[FGD135]

Thanks, JT. Excellent point!

[Grizzly Bare]

Reading 20.7.1B, 7 Take-off climb performance
The CAO never mentions the term "segment" for what we all refer to as 1st, 2nd, 3rd, 4th segment.
7.3.1 and 7.32 refer to the "level flight acceleration manoeuvre", what we'd call 3rd segment, as commencing at a minimum of 400ft.
7.4.1 and 7.4.2 refer to the "en-route configuration" starting at the end of that level flight acceleration - so can be understood to also start at a minimum of 400ft.
Going back to 7.2, it describes the aircraft with gear retracted and at V2. This is what we call 2nd segment and can be understood as stating from establishing in that configuration.
And then back to 7.1.
It states " In the take-off configuration assuming failure of the critical engine so that it is recognised at V1, an aeroplane must be able to climb without ground effect at the speed established as the speed at which the aeroplane becomes airborne and in this configuration, without landing gear retraction, achieve a gross gradient of climb which is positive for two-engined aeroplanes ...".
Not referred to as "first segment", not given a starting height. There is nothing here that states "commences only at 35ft" or "commencing from the end of TOD". This states that the aircraft must be able to climb at VR.
The implication is that the flight path from runway to 35ft (and onwards to completion of gear retraction), where the aircraft starts that manoeuvre at VR must be positive (twin engine aircraft). Notice how between 7.1 and 7.2 there is no mention of acceleration from VR to V2. The CAO states that the"first segment" consideration is solely for climb potential at the speed of VR, it is not an accelerating segment. In any aircraft this "first segment" consideration would extend until the gear is fully retracted (regardless of if it's a slow retraction or not), and only after that point would the "second segment" consideration begin.
But also "first segment" consideration must apply from the moment the aircraft leaves the ground (which would be within the "up to 35ft" area defined by the TOD) as the CAO doesn't mention anything that can be taken to suggest otherwise.

[john_tullamarine]

Reading 20.7.1B, 7 Take-off climb performance

One of the problems for newer folk is an absence of the history. You are reading too much airworthiness significance into 20.7.1B when that is not what it was about originally.

20.7.1B is an operational CAO (originally ANO) and was recast from the airworthiness orders (ANO 101.5/101.6) many decades ago by non-airworthiness folk who didn't always get the story quite aligned with the original.

In turn 101.5/101.6 were based on the UK/FAA airworthiness rules (or was it the other way around ? .. so long ago now, the memory might have the two reversed). Either way, 101.5/101.6 were consigned WPB post Ron Yeats' efforts some years ago. As a consequence, the only words Oz pilots now have available are in 20.7.1B which is a bit sad in this writer's view - it certainly causes problems on occasion.

The CAO never mentions the term "segment" for what we all refer to as 1st, 2nd, 3rd, 4th segment.

However, if you read back to the original O/S documents, you will find references to an option to develop the takeoff NFP by a segmental approach … eg, see the current FAR 25.111(d) https://www.ecfr.gov/cgi-bin/text-idx?SID=16c7974b0f68b39ce0e9da3885b669a5&mc=true&node=se14.1.25_1111&rgn=div8 (https://www.ecfr.gov/cgi-bin/text-idx?SID=16c7974b0f68b39ce0e9da3885b669a5&mc=true&node=se14.1 .25_1111&rgn=div8)

Some aircraft even have a 5th final acceleration segment (eg AW650 under the UK rules).

7.3.1 and 7.3.2 refer to the "level flight acceleration manoeuvre", what we'd call 3rd segment, as commencing at a minimum of 400ft.

.. and 400 ft goes back somewhat further to the ICAO PAMC on Performance, if my recollection is correct, a document to which reference is made on occasion in PPRuNe.

And then back to 7.1. It states " In the take-off configuration assuming failure of the critical engine so that it is recognised at V1

After realising that far too many overruns were occurring on critical runways, that V1 idea went out some years ago in favour of the concept that V1 coincides with the application of the first element of the rejection process and the now common cry that "if you haven't started stopping by V1, then you're going .." (with the failure having occurred at Vef). See, for instance, https://www.faa.gov/other_visit/aviation_industry/airline_operators/training/media/takeoff_safety.pdf

There is nothing here that states "commences only at 35ft" or "commencing from the end of TOD".

But do have a read of FAR 25.115(a) https://www.ecfr.gov/cgi-bin/text-idx?SID=255d3b6cad33ff9c83537e34c8670de5&mc=true&node=se14.1.25_1115&rgn=div8 (https://www.ecfr.gov/cgi-bin/text-idx?SID=255d3b6cad33ff9c83537e34c8670de5&mc=true&node=se14.1 .25_1115&rgn=div8)

The implication is that the flight path from runway to

I really think that you need to re-read the CAO a little more critically and, also, read it in conjunction with the foreign rules from which, ultimately, it derives.

But also "first segment" consideration must apply from the moment the aircraft leaves the ground

If you read all the story, rather than the bits you might choose to support your position, you might relax it a little bit ? The TODR element covers getting to screen, first segment, should it exist, covers the final bit of gear retraction, should that not have been completed by screen. There are words in the airworthiness standards which require positive gradient (capability) at all stages of the takeoff and takeoff flight path. See, example FAR 25.111(a) and (c)(1)

One of the main problems with the present setup is that the design rules which went into the certification of various Types, change. So, Type A met a different set of rules (the frozen design standards) than did Type B. Ergo, one looks up the TCDS to find out what set of rules are applicable. 20.7.1B gives no regard to this. As a consequence, how does the pilot figure out if his/her aircraft AFM actually has any resemblance to whatever 20.7.1B has to say ? Those of us with a suitable background can make a reasonable attempt with some relevant sums but, for the typical pilot, and his FOI who probably doesn't have the background either, both are probably a bit at sea ?

I'm afraid this writer has the idea that Ron missed the boat in the aspect of rubber stamping overseas standards for certification … without introducing any pragmatic means for the local Oz operators and pilots to relate the local rules back to the foreign NAA requirements. I am not aware that this problem has been tested in Court as yet but, if not, it will come eventually and then there will, no doubt, be egg on face in various quarters .. Ron, I suspect, was mainly driven by consideration of QF's situation and, unfortunately, the wider Industry got left behind in the process. I'm not having a go at Ron, he was a fine chap. However, the follow on from his Report didn't dot all the i's and cross all the t's as it could have done ..

[Xeptu]

I agree with everything you have said in post 28 John. Add to that the subtle differences in terminology between European built and certificated aircraft verses US built and certificated aircraft. Pilots historically are not strong with this subject, that's why we are presented with ready made takeoff charts and special procedures. The problem today is that when that information is presented to a captain who knows his stuff, looks at the data and "knows" this can't possibly be right for this runway. This is where we are at today and it's in every airline, then someone dreams up a standard operating procedure change which has a fundamental flaw. it's only a matter of time before all the holes line up, I think we have been lucky but for how much longer.

[Grizzly Bare]

While we may choose to be contemptuous of bureaucrats in Canberra, we're in Oz so the laws of Oz apply. There are many who have been prosecuted over what the law actually said, versus what the law was meant to say.
So, to answer the original question:
20.7.1B 4.1(a) states that TODR and ASDR must consider "aerodrome elevation, ambient temperature, wind component along the runway, runway slope and runway surface conditions ..."
20.7.1B 4.1(b) states that the climb requirements ("segments") must consider "either ambient temperature and aerodrome elevation, or approved declared conditions"
Therefore the answer is: "No, runway slope is not legally required to be factored in to first segment climb through the application of CAO 20.7.1B"

[john_tullamarine]

This is where we are at today and it's in every airline

Which is why the better groups bite the dollar bullet and put a bit more effort into training. Going back a ways now, IPEC took some management decisions to do just that and spent both time and money on initial and recurrent training in performance and weight and balance work. I don't know that I made any of the boys into performance engineers but they certainly had a better level of understanding and appreciation of the the ins and outs than did the majority of other operators' pilots.

While we may choose to be contemptuous of bureaucrats in Canberra

I don't think there is any need for contempt. The majority of the CASA folk try to do a good job and some are extremely knowledgeable and competent.

There are many who have been prosecuted over what the law actually said, versus what the law was meant to say.

But that will only be relevant if there be a delinquency in respect of the requirement. So far as I read this thread, there is no suggestion that any variation should be other than conservative. It is a lemma that the rulebook's requirements specify the minimum standard and there is no adverse concern with those who choose to aspire to a higher placing of the bar.

Therefore the answer is: "No, runway slope is not legally required to be factored in to first segment climb through the application of CAO 20.7.1B"

Definitely the case, as several posters have indicated earlier in the thread. However, there are some situations where it might represent prudent corporate and personal risk management to do so ? This latter consideration is the value represented in this thread, I suggest. The reason for the words (looking more at the originating airworthiness, rather than the operational recasting) is that the concern was with WAT requirements. Terrain avoidance comes into play elsewhere.

[werbil]

I've been trying to work out how much extra performance an aircraft will gain over 1st Segment Performance due ground effect prior to climbing to 35'. I've had to make numerous assumptions to guess a performance gain - can anyone look at the following calculations and confirm whether I'm on the right track?

For the purpose of the exercise, I'm using an aircraft with a wingspan of 66' 8", and a wingtip clearance to the ground with no weight on the undercarriage of approximately 12'. The engines are flat rated to 680SHP each, driving 94" four bladed propellers.

I understand the reduction in induced drag due ground effect is 1.4% at 1 span, 23.5% at 0.25 span, and 47.6% at 0.1 span. The undercarriage does not droop at all during the retraction process, and as the gear doors only have to close behind the gear I'd be surprised if there was any significant increase in drag during the retraction process. Using the quarter span wingtip height of 16'8" results in a wheel clearance of just under five feet, which I believe is good enough for the exercise. Accordingly, we can use an assumed induced drag reduction of 23.5%.

To calculate the amount of thrust available, I have used a speed of 89 KTAS, and assumed a propeller efficiency of 0.8. Using the formula thrust in pounds equals HP x prop efficiency x 326 / KTAS gives 680 * 0.8 * 326 / 89 or 1992 lbs for the single engine case. The aircraft has auto feather, so we can discount the drag effect of a windmilling propeller.

I have found several references that show climb gradient equals (thrust - drag) / weight assuming close to horizontal flight. We're going to assume we're operating at weight of 14,000 lbs in conditions that result in a published first segment climb gradient of 0%. As thrust equals drag in this scenario, total drag out of ground effect equals 1992 lbs.

I am going to have to take a wild guess that induced drag is 50% of total drag at this speed out of ground effect - I really have no idea. Based on this wild assumption, a 23.5% reduction of induced drag is 1992 / 2 * 0.765 or 762 lbs, resulting in a total drag of 1758 lbs.

Plugging these numbers back in the climb gradient formula (1992 - 1758) / 14000 gives a climb gradient of 0.0167 or 1.6%. If this is correct, the aircraft can mush along just above a slightly rising runway whilst the undercarriage is retracted.

Am I on the right track? Is there anyway to improve the above calculations.

[john_tullamarine]

Not knowing the certification background in detail for your particular aeroplane, I can only observe that the first segment data should relate to the post screen component of the gear retraction period (although one will see references to the first segment's being associated with post lift off flight). If your aircraft has been run through the process in the normal manner, then IGE considerations ought not to be of any significant concern for the first segment. However, the main consideration from a corporate risk management perspective is that a court case argument is going to revolve around what the AFM has to say so that remains the principal concern, I suggest.

The takeoff flare to screen is a fairly dynamic period but, whatever sums have been done during the certification workup, they will be validated by the FT workup.(often with a little bit of fudge factoring to suit getting the final numbers right for certification). As a general consideration, I would suggest that trying to analyse the detailed components of climb during the flare (in the absence of windtunnel or FT data) is probably a fairly difficult exercise and fraught with frustration.

[werbil]

The aircraft is commuter category, and the performance graphs in the FMS refer to FAR 23.67 (e) and 23.77 (c). From the FMS "The landing gear was retracted as soon as aircraft had left ground and positive climb rate established. Primary controls were used to control direction and wings level attitude after take-off. Trim and engine power settings were not changed during this phase."

At gross weight at sea level the TODR charts provide a take off distance to 35' on a runway with 1% up slope at temperatures significantly warmer than the first segment chart shows a zero climb gradient. The only way I can see this as being possible is with the assistance of a significant amount of ground affect with the flight path possibly even paralleling the runway at quite a low level until the undercarriage retraction is complete. I appreciate that it is difficult to quantify the amount of benefit gained - I certainly didn't expect it too be as much as the number I came up with.

Unfortunately the AFM is not the ultimate defense. If a pilot believes the performance data is optimistic garbage but relies on it anyway, and a crash proves this to be true, the courts are likely to treat this as reckless.

[john_tullamarine]

The only way I can see this as being possible

Sometimes it is rather difficult to reconcile data differences without input from the manufacturer or the organisation which undertook a post-manufacture STC activitiy.

Unfortunately the AFM is not the ultimate defense.

This view probably would need an appropriate legal opinion to support it. Note CAR (1988) 138 (1) as being the minimum standard. My (non-legally competent) take on this is that the AFM would provide a defence.

Certainly, if an operator/pilot held the view that details in the AFM were non-compliant with the certification basis, then that ought to be drawn to the attention of the Regulator in an appropriate manner. Either the operation should be suspended by the operator or, if the operator holds adequate technical competence, the operation should be varied conservatively with respect to the AFM in order to meet the operator's assessment of the certification requirement pending Regulatory response and possible action.

If a pilot believes the performance data is optimistic garbage

As a general consideration, I see AFM performance data for larger aircraft as being reasonably compliant with the design standards.

One needs to keep in mind that, at times, the certification data may appear to be a little artificial when viewed from out there in real world conditions. That perceived delta then comes within the ambit of an operator's corporate risk management protocols. I noted earlier that, at the now long defunct IPEC Aviation, we made such a decision in respect of first segment concerns for the Argosy. It is always open for any operator to operate to a higher than minimum standard.

At the end of the day, we need to consider two requirements - first, making sure we do not fall below extant regulatory requirements, and second, making sure that we don't scratch the paintwork.

Certainly the AFM is not always infallible. Over the years, I have picked up a couple of AFM technical errors (as well as quite a few administrative errors - including one helicopter which had had the wrong AFM since its initial CofA, years before) which, following subsequent Regulator review, were subject to amendment. Indeed, for a while there, when I was actively involved in Industry audit work, the Regulator was quite cheerfully happy to use me as a defacto AFM review and checking resource.

[werbil]

CASA's favorite, Section 20A of the Act (reckless operation of an aircraft) trumps the Regs. Whilst complying with the AFM is a defence, it may not keep you out of goal.

I believe that I've established a reasonable explanation for what at first glance appeared to be a significant discrepancy between the two charts. As yet no one has yet disproved the validity of my contention, which is a defence for Section 20A.

Getting everyone off the aircraft in the closest possible condition to they got on is my number one priority. Not scratching the paintwork is usually the best way to achieve this.

[john_tullamarine]

Perhaps we should have a beer or two over the AFM at some stage and see what we might be able to figure out ...

[LeadSled]

----------------. Whilst complying with the AFM is a defence, it may not keep you out of goal.
I believe that I've established a reasonable explanation for what at first glance appeared to be a significant discrepancy between the two charts. As yet no one has yet disproved the validity of my contention, which is a defence for Section 20A.
.
Folks,
An interesting sidelight of the CASR 21-35 reforms of 1998 ------ All the old DCA etc little black books aha flight manuals, became legally obsolete.
A quite considerable exercise in comparing the "Australian" performance figures and manufacturers AFM (by whatever name) for common light aircraft, was carried out ----- and there were some startling differences. Never explained was that "Australian" performance figures were almost always more optimistic than the OEM.
Tootle pip!!

[john_tullamarine]

A quite considerable exercise in comparing the "Australian" performance figures and manufacturers AFM (by whatever name) for common light aircraft, was carried out

By whom ? and when ?

there were some startling differences.

No argument, there.

Never explained was that "Australian" performance figures were almost always more optimistic than the OEM.

Now this comment, methinks, is more than a bit over the top. I spent much of my earlier engineering life involved with these flight manuals and compared more than a few here and there. Perhaps you might cite some specific examples, with substantiating data, to support your claim ?

[LeadSled]

JT,
By whom: A team headed by the principle of Southdown Engineering, a well known (then) CAR 35 engineer with substantial light aircraft certification experience, including test flight approval.

Most of the major leg work was done by CASA staff seconded to the CASA Review program office.

OTT: Not really, and we were most surprised, as we expected exactly the opposite ---- give that the "Australian" surface conditions were, as I recall, "short dry grass", not a sealed surface.

We came to the conclusion that a lot of OEM and local "test flying" was pretty rough and ready. Where we found variances, there was no real pattern just differences.

That was also when we discovered that the Chipmunk had never been "properly" certified in Australia.

Unlike the UK., C.of As were just issued to airframes in ex-military condition ---- but not in accord with the ANR/ANOs that applied at the time ----- a good thing, and we had not spent lots of money on meaningless "civil modifications" ---- a significant, (if unintended oversight) variation to DCA at al practice pre 1998.

Tootle pip!!

[john_tullamarine]

Southdown Engineering

Can't bring the organisation to mind. Perhaps you might PM with the principal's name ?

Most of the major leg work was done by CASA staff seconded to the CASA Review program office

Likewise ?

OTT: Not really, and we were most surprised, as we expected exactly the opposite

Having compared more than a few sets of charts, my experience does not support your contention. Again, perhaps you might offer some specifics ?

We came to the conclusion that a lot of OEM and local "test flying" was pretty rough and ready

I concur there. There were some strange outcomes consequent to saving a dollar eg the landing charts based on gross approach speed where the lower weight distances increased. However, they were pretty obvious cheap and nasty workarounds.

the Chipmunk had never been "properly" certified in Australia.

I had some involvement with several Chippies. Perhaps you can indicate where the deficiencies lay ?

C.of As were just issued to airframes in ex-military condition

Don't recall ever being involved with ex-MIL machines so I can't comment there.

[LeadSled]

JT,
A reply in part, re. the Chipmunk:

The deficiencies were legal process, not the aeroplane.

When the ARB certified the aircraft in UK, there was a laundry list of meaningless modifications, in my view not one of them made any difference to the safe operation of the aircraft. They cost a lot of money to carry out. Fundamentally, military and civil didn't recognise each other, much the same for pilots, SAL4 Pilot Licensing didn't recognise military qualification beyond just hours logged.

As you will well recall, the ANR/ANOs had a well defined process for certifying any aircraft to "Australian standards", which added sometimes tens of thousands of pounds/dollars to the cost of putting an aircraft on the register, and doing a "first of type" certification was a long and painful business ---- and you may recall that the number of aircraft damaged by DCA "test flying" resulted in no insurance coverage for such flying, the "Pool" said no.

Somehow or other, that process was never visited on the Chipmunk. We speculated that the most likely reason was that Sir Donald Anderson was patron of Royal Newcastle Aero Club, but we don't really know. There was no "first of type", the aircraft were just given individual C.of As.

To this day, a little seaplane, a Riviera, rests at the bottom of Pittwater, the damage to DCA's own Merlin at Mangalore, and Max Hazelton fought a long court battle to recover damages from the Commonwealth, subsequent to a test flying "event" during "certification" ---- I think that was the first Beech 1900, two cooked engines and structural damage, but not as bad as the Merlin.

Re: Southdown Engineering, think Seabird Seeker, Jabiru and several others, first degree from Sydney (we started Engineering the same day) and long time in DCA in Melbourne in Airworthiness early in his career. Later, engineering-wise, ran the CSIRO F-27, for all the interesting things it got up to. Headed up the Airworthiness Tec. Subcommittee of the CASA Review from 1997-1999. First person to hold a CASA delegation to sign off for a Type Certificate, other than a CASA employee ---- an idea stoutly resisted by the "iron ring" in CASA, but an intent of Part 21.

Tootle pip!!

[john_tullamarine]

When the ARB certified the aircraft in UK,

Indeed

Somehow or other, that process was never visited on the Chipmunk.

I was not aware of that history. I doubt that Donald George would have had any direct involvement .. small world, though, I completed my PPL at RNAC with Stan and Jack, many years ago, now.

Re: Southdown Engineering,

Ah, DL - of course - a fine and honourable chap, if ever there were one. Long time since he and I have crossed paths, hopefully he enjoys good health in his retirement ?

First person to hold a CASA delegation to sign off for a Type Certificate, other than a CASA employee

That's probably not quite the case. There was a number of OEM engineers who held FOT AP appointments. For instance, I had ANR 27/40/41 from the mid-70s, courtesy of the long-departed and illustrious Edward Mannix B. And the earlier chaps prior to me with that OEM, I am sure, would have predated DL's appointment.

However, can you provide some specifics re the suggestion regarding P-chart problems ?

[LeadSled]

However, can you provide some specifics re the suggestion regarding P-chart problems ?
Afraid not, any copies of paperwork on the particular issue that I might have had have long since been archived, and I no long have (or really want to have) access, all I can recount is the general outline of what we found.

Re. "the first", I was really referring to certifying a new design in Australia, not first of type/type acceptance of an import.
The particular delegation was issued pursuant to a clause in Part 21 that CASA subsequently deleted when nobody was looking ---- no consultation, nothing that made the situation clear to the Minister of the day etc., nothing in the explanatory memorandum with the "amendments", and it is much harder to pick up a subtraction than an edition.
The particular provision enabled "industry certification" for aircraft up to 750 kg, and was a provision put together by DL and RSJW, and, of course, initially Leroy Keith.

Tootle pip!!

PS: As the OEM POH/AFM were, for all examined, more restrictive than the DCA books, we decided that there was no problem that required more time and effort.

[zzuf]

JT,
Max Hazelton fought a long court battle to recover damages from the Commonwealth, subsequent to a test flying "event" during "certification" ---- I think that was the first Beech 1900, two cooked engines and structural damage, but not as bad as the Merlin.
Tootle pip!!
I recall working with DL while he was a departmental officer and during his later involvement as project engineer/TP with many of the aircraft I flew.
He made pretty nice violins as well.
But I mostly enjoyed the things I bought after certain parties made claims about the Beech 1900 then settled out of court.
Seems that they were advised that hearsay was not a good basis for public criticism.

[john_tullamarine]

As the OEM POH/AFM were, for all examined, more restrictive than the DCA books

Some differences were due to differences in rules, eg the 500S GW change. In general, though, I think I have to continue to disagree with your overall assessment. I thought the local product generally was pretty reasonable for operational use. Perhaps we should just agree to disagree ?

He made pretty nice violins as well.

Learn something new every day. A talented chap, indeed.

[LeadSled]

As the OEM POH/AFM were, for all examined, more restrictive than the DCA books
Some differences were due to differences in rules, eg the 500S GW change. In general, though, I think I have to continue to disagree with your overall assessment. I thought the local product generally was pretty reasonable for operational use. Perhaps we should just agree to disagree ?
He made pretty nice violins as well.
.
JT,
I am/was not really making of a relative quality assessment of either.

Our concern, at the time, was that, as the DCA et al Flight Manuals would no longer have a legal existence, that OEM data didn't present any bear traps. It was an instructive exercise all round. We had had some concerns that some thought that marketing departments of at least one US OEM "created" the performance number, with the assistance of their legal departments.

Re. violins, probably not a surprising interest, his father was first violin in the SSO for many years.

Re. the Aero Commander 500S ---- I can advise you, from personal experience, the current TC holder doesn't want to know about Australian airframes that have been operating at "Australian" weights --- that even "thinking" about it could generate a liability. Personally, I do not believe the operation at increased weight was significant in the two AU losses due wing structural failure in the air, outboard of the engines.

DL does do a very good presentation on the root cause of the AC wing root cracking and subsequent ADs.
Tootle pip!!

[john_tullamarine]

OEM data didn't present any bear traps.

Oh, there be dragons awaiting the unwary in some areas ... probably not too much of a concern now that all the older P-chart folk are dying off, I guess. Having run up a few of the P-charts, I thought the DCA approach was more than reasonable for GA purposes.

his father was first violin in the SSO for many years

Ernest. Of that I was unaware. Small world - until aeroplanes interfered with my plans as a younger chap, I was heading towards a career as a professional flautist (a student of Victor McMahon in Sydney). A number of my schoolboy buddies continued on with instrumental work and ended up in this and that SO around the country. Ah, the most fond memories of the Sydney Con ... but let's not go there so that the guilty be protected from their youthful inappropriatenesses, as it were ...
.
Re. the Aero Commander 500S

I have no current knowledge of the situation. However, the basis for the recertification was component comparison to heavier airframes with whatever changes were required and the GW ending up limited per the ANO 101.22 OEI climb requirement - made a useful difference VFR ops. The US basis was, as I recall, the climb limited requirement. On a like tack, I did a similar recert for the 500A some time later and on the same basis. I fail to see that there would be any real concern regarding the increased weights from a point of airworthiness signficance ?