Perf Group A history
Thread Starter
Perf Group A history
I have been trying to establish, out of idle curiosity, the history of the development of aircraft Performance Groups, particularly Perf “A”, with its rigorous treatment of engine-out operation. Web searches have produced little info.
I have seen a claim that Perf A originated with FAR25, which was first published in 1965, and that the first type certificated to FAR25 was the B737. Is that correct
This raises a few queries. What standard applied before that? To what standard were 1950s propliners, the Comet, B707, and DC-8 certified in respect of engine-out operation? I know that the FAA-approved B707 was rejected by the UK ARB, which required significant changes to the fin (vertical stabilizer if you’re from the US) and the rudder boost to improve engine-out go-around controllability.
Clearly, at that stage, there were major differences between national authorities. I suspect that alignment improved later – but the UK CAA still required changes to the Mmo of the B767 in the mid-80s.
When Perf A appeared, was it applied retrospectively to existing types? I recall that, maybe about late 60s, there were reductions imposed in the UK on the MGW of the DC-3, which were said at the time to make the type commercially unviable. Though, of course, it carried on flying for many years. I assume the change was to improve engine-out performance.
Further queries on performance criteria for some RAF types. I recall conversations with Shackleton pilots back in the 60s over a beer or three; they lived at times with a 20 knot gap on take-off between the stop speed and the go speed, thus giving in that speed band a horrid choice between a slow crash and a fast one. This was in the context of Gibraltar, with its short 6000ft runway, and Sharjah, rather longer but with temperatures frequently up to 40 deg C or so. Did that always apply? Or, at UK bases such as St Mawgan and Kinloss with longer runways, was there a higher level of safety?
Also, for the A-W Argosy, similar conversations in which I was told that at times they operated to “military performance standards”, whatever they were. The RAF Argosy first flew in 1961, so pre-dates (I think) Perf A. Did they operate to Perf A in normal times? What was the permitted degradation to “mil perf standards”, and in what circumstances could that be used?
I hope there may be some performance engineers out there with relevant knowledge.
I have seen a claim that Perf A originated with FAR25, which was first published in 1965, and that the first type certificated to FAR25 was the B737. Is that correct
This raises a few queries. What standard applied before that? To what standard were 1950s propliners, the Comet, B707, and DC-8 certified in respect of engine-out operation? I know that the FAA-approved B707 was rejected by the UK ARB, which required significant changes to the fin (vertical stabilizer if you’re from the US) and the rudder boost to improve engine-out go-around controllability.
Clearly, at that stage, there were major differences between national authorities. I suspect that alignment improved later – but the UK CAA still required changes to the Mmo of the B767 in the mid-80s.
When Perf A appeared, was it applied retrospectively to existing types? I recall that, maybe about late 60s, there were reductions imposed in the UK on the MGW of the DC-3, which were said at the time to make the type commercially unviable. Though, of course, it carried on flying for many years. I assume the change was to improve engine-out performance.
Further queries on performance criteria for some RAF types. I recall conversations with Shackleton pilots back in the 60s over a beer or three; they lived at times with a 20 knot gap on take-off between the stop speed and the go speed, thus giving in that speed band a horrid choice between a slow crash and a fast one. This was in the context of Gibraltar, with its short 6000ft runway, and Sharjah, rather longer but with temperatures frequently up to 40 deg C or so. Did that always apply? Or, at UK bases such as St Mawgan and Kinloss with longer runways, was there a higher level of safety?
Also, for the A-W Argosy, similar conversations in which I was told that at times they operated to “military performance standards”, whatever they were. The RAF Argosy first flew in 1961, so pre-dates (I think) Perf A. Did they operate to Perf A in normal times? What was the permitted degradation to “mil perf standards”, and in what circumstances could that be used?
I hope there may be some performance engineers out there with relevant knowledge.
Ahh you need to correspond with John Tullamarine, I gave him my copy of the "Final Report of the ICAO Standing Committee on Performance" circa 1955. This will give a good background to the development of modern (civil) performance standards. Probably a good starting point.
D. P. Davies "Handling the Big Jets" has some detail on the development of jet transport performance standards, from a certification TP's view.
Old British military, probably AVP970, but don't really recall.
Cheers.
D. P. Davies "Handling the Big Jets" has some detail on the development of jet transport performance standards, from a certification TP's view.
Old British military, probably AVP970, but don't really recall.
Cheers.
Last edited by zzuf; 23rd Feb 2018 at 11:50.
Thread Starter
A now deleted post included the statement "I've never heard of Perf A".
We have a terminology problem. UK national regs, specifically BCARs (British Civil Airworthiness Requirements) were the regs under which I first encountered public transport performance requirements, in the late 1970s. These were replaced by JAR 25 in the 1990s.
BCARs had several performance Groups, the highest of which, Group A, applied to aircraft with more than 19(?) seats or max gross weight of 5700kg. It required the aircraft to be able to tolerate the loss of the power of one engine at any time from brake release to the end of the landing roll. Other Groups applied to smaller aircraft and were less demanding.
Thus Group A was addressing broadly the same types as FAR 25, with broadly the same performance requirements.
The now deleted post included a link to a Flight Safety Foundation document that addressed some of the background I was looking for, such as the US codes under CAR4b that covered propliners and predated JAR25. No sign yet of the early US or UK jet certification standards.
I'm aware that AvP970 was the UK military design standard source. Its successor, DefStan970, is available online, but 1950ish AvP970 so far eludes me.
So, some progress; thank you.
We have a terminology problem. UK national regs, specifically BCARs (British Civil Airworthiness Requirements) were the regs under which I first encountered public transport performance requirements, in the late 1970s. These were replaced by JAR 25 in the 1990s.
BCARs had several performance Groups, the highest of which, Group A, applied to aircraft with more than 19(?) seats or max gross weight of 5700kg. It required the aircraft to be able to tolerate the loss of the power of one engine at any time from brake release to the end of the landing roll. Other Groups applied to smaller aircraft and were less demanding.
Thus Group A was addressing broadly the same types as FAR 25, with broadly the same performance requirements.
The now deleted post included a link to a Flight Safety Foundation document that addressed some of the background I was looking for, such as the US codes under CAR4b that covered propliners and predated JAR25. No sign yet of the early US or UK jet certification standards.
I'm aware that AvP970 was the UK military design standard source. Its successor, DefStan970, is available online, but 1950ish AvP970 so far eludes me.
So, some progress; thank you.
Last edited by kenparry; 24th Feb 2018 at 09:04. Reason: typo
Moderator
Some thoughts .. noting that I don't claim to have much in the way of specific knowledge of what went on in the real olden days ..
I have been trying to establish, out of idle curiosity, the history of the development of aircraft Performance Groups, particularly Perf “A”
A specifically British thing.
If you run some searches you will find the odd document of interest to this question .. eg Chaplin's paper. I suspect that references to "Performance A" in the pilot fraternity refer more to the pilot licensing theory examinations rather than the certification airworthiness regulations.
I have seen a claim that Perf A originated with FAR25, which was first published in 1965
Can't speak authoritatively as to the commencing date, but I suspect somewhat before the mid-60s. I did my theory subjects around that time and, as I recall, references to Perf A in the British system were not new. As to the first Part 25 certification, that would take some research which I will leave to you .. you might start with the TCDS for a range of aircraft; the sheets will give you the certification basis for the Types involved.
What standard applied before that?
There was a range of standards developed prior to the jet age. A reference cited later in this post will give you a bit of a rundown on the specifics.
Clearly, at that stage, there were major differences between national authorities.
Indeed. In recent years the harmonisation of, especially, European and US standards has seen a more sensible life for the OEMs
When Perf A appeared, was it applied retrospectively to existing types?
Here you are thinking of BCAR Group A (if my memory hasn't atrophied too much), which was the heavy airworthiness regulations rather than Perf A, which related more to pilot theory exams. Perf A caused much head scratching and pencil and paper work in the graphs to get folks to the standard where they could pass the relevant exams.
As a general observation, rule changes are not retrospective as this, often, would kill the old Types which hadn't been designed with knowledge of the newer rule. So, for example, the 2 second ASD fudge factor in FAR 25 A/L 42 was not retrospective, so far as I am aware.
reductions imposed in the UK on the MGW of the DC-3
I have no knowledge of that exercise
Further queries on performance criteria for some RAF types.
I can't speak to the RAF but, based on comments from RAAF flyers of that era, I have the impression that the system was more on the basis of TLAR .. ie we got over the fence last week so it should still be OK this week.
for the A-W Argosy, similar conversations in which I was told that at times they operated to “military performance standards”
The RAF may well have operated to weights in excess of the civil requirements.
For this Type I had plenty of performance exposure, having looked after IPEC's performance for quite a few years. The Australian certification essentially rubber stamped the UK requirements. I would have to dig out some AFMs from the filing cabinets to check just what the UK basis was but the AFMs were bog standard Perf A data .. think FAR 25 in general. In fact, typical of many UK manuals, the performance charts were great to work with as they gave all the various limitations as separate information.
I gave him my copy of the "Final Report of the ICAO Standing Committee on Performance"
Indeed .. and, again, many thanks to my colleague zzuf for the donation. I had been hunting for a copy on and off for years. zzuf's copy comes from a line of well-regarded Australian airworthiness regulatory stalwarts, including his good self. Reading the names on the cover, I remain somewhat humbled in the presence of such august company.
Prior to the Standing Committee's report, things were a bit TLAR and simplistic in the performance arena.
The rapid developments post WW2 led ICAO to a desire to get ahead of the action and develop more appropriate Standards. The upshot was the development of the PAMC on Performance which applied a much more rigorous and statistically based rationale to aircraft performance.
If I recall correctly, the then-recently certificated F27 was the first Type to be (re-)certificated to the PAMC. Again some further information in later references.
A now deleted post included the statement "I've never heard of Perf A".
The post referred to was by IGh who chose to delete it for his own reasons. A pity, as the post was quite useful and, while I won't reinstate it out of deference to the poster, the main details were
(a) a link to a paper by Wagenmakers, a quite experienced and influential airline performance guru back in those days.
(b) reference to Wagenmaker's reference text
(c) some references to the Boeing performance engineering manual Jet Transport Performance Methods. This document, which has been revised over the years, is a basic engineering reference text for the subject and is used by Boeing for training courses for airline ops engineering folks. For those who wish to read a copy, you shouldn't have too much difficulty finding a download on the net.
He made a reference to one edition (which I don't have) with credits to Walt ? Walt presumably is Walter Blake, a fine chap (now well-retired) but still active in the Industry. Walt, as I recall, was the Boeing performance boss for some years and is a very knowledgeable performance engineer quite apart from being a very nice bloke.
To give you some idea of how the very early regs were made, I recall some commentary by a chap at a training course (also attended by zzuf as a CASA - or whatever name it was that week - observer). This chap, whose name I can't recall, had been a junior engineer in the US regulator at the time. He gave two examples
(a) light aircraft maximum stall speed. Finger in the wind figure of 70 mph picked as being a reasonable balance for OEM design and crashworthiness survival.
(b) 50 ft screen height for light aircraft. This was based on a Curtiss demo at a military parade ground. The parade ground was surrounded by trees of about 50 ft height .. seemed as good an idea as any for starters.
While things had to start somewhere, one sees the eventual need for developing rigorous analytical approaches cf the PAMC on Performance.
I have been trying to establish, out of idle curiosity, the history of the development of aircraft Performance Groups, particularly Perf “A”
A specifically British thing.
If you run some searches you will find the odd document of interest to this question .. eg Chaplin's paper. I suspect that references to "Performance A" in the pilot fraternity refer more to the pilot licensing theory examinations rather than the certification airworthiness regulations.
I have seen a claim that Perf A originated with FAR25, which was first published in 1965
Can't speak authoritatively as to the commencing date, but I suspect somewhat before the mid-60s. I did my theory subjects around that time and, as I recall, references to Perf A in the British system were not new. As to the first Part 25 certification, that would take some research which I will leave to you .. you might start with the TCDS for a range of aircraft; the sheets will give you the certification basis for the Types involved.
What standard applied before that?
There was a range of standards developed prior to the jet age. A reference cited later in this post will give you a bit of a rundown on the specifics.
Clearly, at that stage, there were major differences between national authorities.
Indeed. In recent years the harmonisation of, especially, European and US standards has seen a more sensible life for the OEMs
When Perf A appeared, was it applied retrospectively to existing types?
Here you are thinking of BCAR Group A (if my memory hasn't atrophied too much), which was the heavy airworthiness regulations rather than Perf A, which related more to pilot theory exams. Perf A caused much head scratching and pencil and paper work in the graphs to get folks to the standard where they could pass the relevant exams.
As a general observation, rule changes are not retrospective as this, often, would kill the old Types which hadn't been designed with knowledge of the newer rule. So, for example, the 2 second ASD fudge factor in FAR 25 A/L 42 was not retrospective, so far as I am aware.
reductions imposed in the UK on the MGW of the DC-3
I have no knowledge of that exercise
Further queries on performance criteria for some RAF types.
I can't speak to the RAF but, based on comments from RAAF flyers of that era, I have the impression that the system was more on the basis of TLAR .. ie we got over the fence last week so it should still be OK this week.
for the A-W Argosy, similar conversations in which I was told that at times they operated to “military performance standards”
The RAF may well have operated to weights in excess of the civil requirements.
For this Type I had plenty of performance exposure, having looked after IPEC's performance for quite a few years. The Australian certification essentially rubber stamped the UK requirements. I would have to dig out some AFMs from the filing cabinets to check just what the UK basis was but the AFMs were bog standard Perf A data .. think FAR 25 in general. In fact, typical of many UK manuals, the performance charts were great to work with as they gave all the various limitations as separate information.
I gave him my copy of the "Final Report of the ICAO Standing Committee on Performance"
Indeed .. and, again, many thanks to my colleague zzuf for the donation. I had been hunting for a copy on and off for years. zzuf's copy comes from a line of well-regarded Australian airworthiness regulatory stalwarts, including his good self. Reading the names on the cover, I remain somewhat humbled in the presence of such august company.
Prior to the Standing Committee's report, things were a bit TLAR and simplistic in the performance arena.
The rapid developments post WW2 led ICAO to a desire to get ahead of the action and develop more appropriate Standards. The upshot was the development of the PAMC on Performance which applied a much more rigorous and statistically based rationale to aircraft performance.
If I recall correctly, the then-recently certificated F27 was the first Type to be (re-)certificated to the PAMC. Again some further information in later references.
A now deleted post included the statement "I've never heard of Perf A".
The post referred to was by IGh who chose to delete it for his own reasons. A pity, as the post was quite useful and, while I won't reinstate it out of deference to the poster, the main details were
(a) a link to a paper by Wagenmakers, a quite experienced and influential airline performance guru back in those days.
(b) reference to Wagenmaker's reference text
(c) some references to the Boeing performance engineering manual Jet Transport Performance Methods. This document, which has been revised over the years, is a basic engineering reference text for the subject and is used by Boeing for training courses for airline ops engineering folks. For those who wish to read a copy, you shouldn't have too much difficulty finding a download on the net.
He made a reference to one edition (which I don't have) with credits to Walt ? Walt presumably is Walter Blake, a fine chap (now well-retired) but still active in the Industry. Walt, as I recall, was the Boeing performance boss for some years and is a very knowledgeable performance engineer quite apart from being a very nice bloke.
To give you some idea of how the very early regs were made, I recall some commentary by a chap at a training course (also attended by zzuf as a CASA - or whatever name it was that week - observer). This chap, whose name I can't recall, had been a junior engineer in the US regulator at the time. He gave two examples
(a) light aircraft maximum stall speed. Finger in the wind figure of 70 mph picked as being a reasonable balance for OEM design and crashworthiness survival.
(b) 50 ft screen height for light aircraft. This was based on a Curtiss demo at a military parade ground. The parade ground was surrounded by trees of about 50 ft height .. seemed as good an idea as any for starters.
While things had to start somewhere, one sees the eventual need for developing rigorous analytical approaches cf the PAMC on Performance.
Thread Starter
john t:
Many thanks, I had hoped you would be able to make a contribution. You may well be correct about Perf "A" being related to pilot licensing - that was the context in which I met it.
Yes, the post by IGh was helpful, and thanks to you for repeating the links that he had posted.
Many thanks, I had hoped you would be able to make a contribution. You may well be correct about Perf "A" being related to pilot licensing - that was the context in which I met it.
Yes, the post by IGh was helpful, and thanks to you for repeating the links that he had posted.
John, I am requently amazed by your breadth of knowledge. Thank you. By the way I did my Performance A exam in 1962.
I recall from the mid 1950's at RAAF Base Townsville, a USAF RB66 "Destroyer" taking off on Runway 01 which was then about 8000 ft in length and at sea level. . In those days several RAAF airfields had Distance to Go marker boards on the flight strips. I believe that was because some military aircraft used Refusal Speeds as a rough check of take off performance. It not at a certain speed by a certain distance down the runway the pilot rejected the take off.
On this occasion the B66 was a long way down the runway in its take off roll when the pilot aborted using the braking parachute as well as brakes.
It taxied back and 20 minutes later tried another take off and this time it kept going.
I suspected the pilot wanted to get home to Guam for a date
Since then, I often wondered how many military aircraft of that era aborted their take off run unnecessarily; especially as marker boards v airspeed as means of judging acceleration, was only an approximation. Some years later the RAAF dumped the idea and marker boards disappeared from military airfields.
Again, in those days, there was no such thing as take off performance charts included in RAF/RAAF Pilot's notes for type. You simply opened the throttles and went. If the runway was short you pulled back the stick when there was no runway left and hoped for the best. Believe me, I am serious! The Lincoln Pilots Notes published a recommended lift off speed and a Take-Off Safety Speed (asymmetric).
For example the Avro Lincoln PN stated in part:
At 65,000 lbs ease (rotation hadn't been invented then) the aircraft off the ground at between 100-105 knots.
75,000 lbs ditto 105-110 knots
82,000 lbs ditto 110-115 knots.
There was nothing about how much runway you needed for take off and landing at various density altitudes.
For example. The length of Momote airstrip on Manus Island,north of New Guinea, was 5200 ft. There was no over-run except to ditch into the sea. It became a case of sticking up one's wetted finger to judge the w/v and go with full power +18 lbs/sq inch boost (manifold pressure) through the throttle gate. The plan was to lift off the ground before running into the shark infested water at the end of the runway. It was safer to keep on going with an engine failure or burst tyre because an abort would be fatal.
I well recall on one take off at Momote, nil wind, the rear gunner who (naturally) faced the rear seated between his two 0.5 calibre machine guns, could see the runway going away from him, remarking upon the four trails of propeller slipstream ruffling the surface of the sea as we built up airspeed at 100 feet towards asymmetric safety speed of 135 knots. Ops normal for that era, with take off performance considerations non-existent since there were no published charts. Things were so simple, then.
On this occasion the B66 was a long way down the runway in its take off roll when the pilot aborted using the braking parachute as well as brakes.
It taxied back and 20 minutes later tried another take off and this time it kept going.
I suspected the pilot wanted to get home to Guam for a date
Since then, I often wondered how many military aircraft of that era aborted their take off run unnecessarily; especially as marker boards v airspeed as means of judging acceleration, was only an approximation. Some years later the RAAF dumped the idea and marker boards disappeared from military airfields.
Again, in those days, there was no such thing as take off performance charts included in RAF/RAAF Pilot's notes for type. You simply opened the throttles and went. If the runway was short you pulled back the stick when there was no runway left and hoped for the best. Believe me, I am serious! The Lincoln Pilots Notes published a recommended lift off speed and a Take-Off Safety Speed (asymmetric).
For example the Avro Lincoln PN stated in part:
At 65,000 lbs ease (rotation hadn't been invented then) the aircraft off the ground at between 100-105 knots.
75,000 lbs ditto 105-110 knots
82,000 lbs ditto 110-115 knots.
There was nothing about how much runway you needed for take off and landing at various density altitudes.
For example. The length of Momote airstrip on Manus Island,north of New Guinea, was 5200 ft. There was no over-run except to ditch into the sea. It became a case of sticking up one's wetted finger to judge the w/v and go with full power +18 lbs/sq inch boost (manifold pressure) through the throttle gate. The plan was to lift off the ground before running into the shark infested water at the end of the runway. It was safer to keep on going with an engine failure or burst tyre because an abort would be fatal.
I well recall on one take off at Momote, nil wind, the rear gunner who (naturally) faced the rear seated between his two 0.5 calibre machine guns, could see the runway going away from him, remarking upon the four trails of propeller slipstream ruffling the surface of the sea as we built up airspeed at 100 feet towards asymmetric safety speed of 135 knots. Ops normal for that era, with take off performance considerations non-existent since there were no published charts. Things were so simple, then.
Last edited by Centaurus; 25th Feb 2018 at 03:03.
Thread Starter
Bergerie1:
Thanks for that; it takes Perf "A" back to before FAR25. Can you remember the sample aircraft type on which the paper was then based? Mine was somewhat later, 1978, and used the L1011.
Centaurus:
The UK's V-force used similar marker boards and go/stop speeds. I'm not aware of how the speed was calculated or how many variables were considered.
My military flying was all single-engine, so my initiation to the complications of multi-engine performance came only when I moved into the airline world. For the Hunter, in the late 60s, we had limited runway performance data, but it did include the ability to work out a ground roll distance. The engine failure case was simple, of course, in principle: stop or Martin Baker exit. However, there was no way of deriving a stop speed. The only info was a quoted "emergency braking speed", which IIRC was 100kt. Some problems with that: our only speed indication was IAS, and the single quoted speed took no account of what we then called take-off weight. I suppose the Perf A nearest equivalent is Brake Energy Limit, but that does account for at least some of the related variables.
By the way I did my Performance A exam in 1962.
Centaurus:
The UK's V-force used similar marker boards and go/stop speeds. I'm not aware of how the speed was calculated or how many variables were considered.
My military flying was all single-engine, so my initiation to the complications of multi-engine performance came only when I moved into the airline world. For the Hunter, in the late 60s, we had limited runway performance data, but it did include the ability to work out a ground roll distance. The engine failure case was simple, of course, in principle: stop or Martin Baker exit. However, there was no way of deriving a stop speed. The only info was a quoted "emergency braking speed", which IIRC was 100kt. Some problems with that: our only speed indication was IAS, and the single quoted speed took no account of what we then called take-off weight. I suppose the Perf A nearest equivalent is Brake Energy Limit, but that does account for at least some of the related variables.
Last edited by kenparry; 25th Feb 2018 at 08:21.
Info U.K. CAA 2006 (JAR)
https://publicapps.caa.co.uk/docs/33/CAP698.pdf
CAA JAR-FCL Examinations Aeroplane Performance Manual
Engine out perf may have orrigionated from ICAO obstacle clearance studies?
P.S. The paper ‘Analysis if takeoff performance’ 1967 refers to BCAR. There may be other refs of interest.
http://naca.central.cranfield.ac.uk/...rc/cp/1034.pdf
References (#2) British Civil Aircraft Requirements 1966 section D
https://publicapps.caa.co.uk/docs/33/CAP698.pdf
CAA JAR-FCL Examinations Aeroplane Performance Manual
Engine out perf may have orrigionated from ICAO obstacle clearance studies?
P.S. The paper ‘Analysis if takeoff performance’ 1967 refers to BCAR. There may be other refs of interest.
http://naca.central.cranfield.ac.uk/...rc/cp/1034.pdf
References (#2) British Civil Aircraft Requirements 1966 section D
Last edited by PEI_3721; 25th Feb 2018 at 09:22.
john_tullamarine, Re RAF Argosy Military Operating Standards, personally, was never required to use them and always operated to Perf A - Phew!
I can't recollect the approximate difference in what we could lift or TOD/TOR required but I know a man who probably can. Surprised he hasn't turned up to comment.
I can't recollect the approximate difference in what we could lift or TOD/TOR required but I know a man who probably can. Surprised he hasn't turned up to comment.
Moderator
Biggest problem with the AW Queen of the Skies was its invariable, miserable, abysmal first segment performance. Far more than any other aircraft I have dealt with, first segment gradient was a regular constraint on TOW.
Then again, those main legs went up a long way to the cowls.
Then again, those main legs went up a long way to the cowls.
There is a book and a film by David Beatty called Cone of Silence about performance problems with a fictional airliner. The film uses an Avro Ashton.
Flight International reviewed the film in 1960 and made a reference to jet runway lengths ,ground stall effects and manual unstick speeds being again under close review.
https://www.flightglobal.com/pdfarch...0-%200610.html
Flight International reviewed the film in 1960 and made a reference to jet runway lengths ,ground stall effects and manual unstick speeds being again under close review.
https://www.flightglobal.com/pdfarch...0-%200610.html
Last edited by tubby linton; 25th Feb 2018 at 10:06.
Can you remember the sample aircraft type on which the paper was then based? Mine was somewhat later, 1978, and used the L1011.
I believe that the type used prior to that was the Britannia.
Basil:
I have indeed operated the Argosy to MOS including in the Middle East. Basically speaking, the MTOW went up from 97,000 lbs to 105,000 lbs. I have come out of Bait al Falaj at the latter weight so TORA wasn't a problem but an engine failure could not be contemplated.
I have indeed operated the Argosy to MOS including in the Middle East. Basically speaking, the MTOW went up from 97,000 lbs to 105,000 lbs. I have come out of Bait al Falaj at the latter weight so TORA wasn't a problem but an engine failure could not be contemplated.
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Here's what I found on Wikipedia about the history of Part 25:
Part 25
This part contains airworthiness standards for airplanes in the transport category.
Transport category airplanes are either:
Jets with 10 or more seats or a maximum takeoff weight (MTOW) greater than 12,500 pounds (5,670 kg); or
Propeller-driven airplanes with greater than 19 seats or a MTOW greater than 19,000 pounds (8,618 kg).
A rather important section of this part, is the 121 - climbing guaranteed with one engine out for multi-engine aircraft.
The Boeing 737 and later types, and Airbus A300 series, are well-known airplane types that were certified according to standards set out in FAR Part 25.
Most of the Federal Aviation Regulations, including Part 25, commenced on February 1, 1965. Prior to that date, airworthiness standards for airplanes in the transport category were promulgated in Part 4b of the US Civil Air Regulations which was in effect by November 1945. Effective August 27, 1957, Special Civil Air Regulation (SR) 422 was the basis for certification of the first turbine-powered transport airplanes, such as the Boeing 707, the Lockheed Electra, and the Fairchild 27. SR 422A became effective July 2, 1958, and was superseded by SR 422B, effective August 29, 1959. Only a few airplanes were certified under SR 422A, such as the Gulfstream I and the CL-44. First generation turbine-powered transport category airplanes such as the DC-8, DC-9, and B-727, were originally certified under SR 422B. SR 422B was recodified with minor changes to 14 CFR part 25, which became effective February 1965.
This part contains airworthiness standards for airplanes in the transport category.
Transport category airplanes are either:
Jets with 10 or more seats or a maximum takeoff weight (MTOW) greater than 12,500 pounds (5,670 kg); or
Propeller-driven airplanes with greater than 19 seats or a MTOW greater than 19,000 pounds (8,618 kg).
A rather important section of this part, is the 121 - climbing guaranteed with one engine out for multi-engine aircraft.
The Boeing 737 and later types, and Airbus A300 series, are well-known airplane types that were certified according to standards set out in FAR Part 25.
Most of the Federal Aviation Regulations, including Part 25, commenced on February 1, 1965. Prior to that date, airworthiness standards for airplanes in the transport category were promulgated in Part 4b of the US Civil Air Regulations which was in effect by November 1945. Effective August 27, 1957, Special Civil Air Regulation (SR) 422 was the basis for certification of the first turbine-powered transport airplanes, such as the Boeing 707, the Lockheed Electra, and the Fairchild 27. SR 422A became effective July 2, 1958, and was superseded by SR 422B, effective August 29, 1959. Only a few airplanes were certified under SR 422A, such as the Gulfstream I and the CL-44. First generation turbine-powered transport category airplanes such as the DC-8, DC-9, and B-727, were originally certified under SR 422B. SR 422B was recodified with minor changes to 14 CFR part 25, which became effective February 1965.
Thread Starter
aterpster: thanks, that pins down the code used for the early jets, and confirms the FAR25 date.
JW411 and Basil: Wow, I would have thought Bait to be exciting enough at Perf A without going heavier. I never went there, but heard you guys talking about it in the Muharraq bar. Who could authorise use of MOS? Was it Capt's discretion, OC Ardet, or higher up the food chain? And what was the level of need? Just a heavy load day, or something more urgent?
JW411 and Basil: Wow, I would have thought Bait to be exciting enough at Perf A without going heavier. I never went there, but heard you guys talking about it in the Muharraq bar. Who could authorise use of MOS? Was it Capt's discretion, OC Ardet, or higher up the food chain? And what was the level of need? Just a heavy load day, or something more urgent?
tubby L
'Cone of Silence' was based on Harry Foote's accident at Ciampino:-
https://aviation-safety.net/database...?id=19521026-0
I flew with him several years later on a Britannia.
Read my post about D.P. Davies and his comments in the second audio.
Nothing like blaming the pilot when a problem is not fully understood!
D P Davies interviews on certificating aircraft
'Cone of Silence' was based on Harry Foote's accident at Ciampino:-
https://aviation-safety.net/database...?id=19521026-0
I flew with him several years later on a Britannia.
Read my post about D.P. Davies and his comments in the second audio.
Nothing like blaming the pilot when a problem is not fully understood!
D P Davies interviews on certificating aircraft