BN2 Islander
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BN2 Islander
Hi guys,
Could anyone point me in the direction of some speed performance data, power settings and/or checklist for the BN2 Islander? I have been scouring all over the web but cannot find what I'm looking for.
Could anyone point me in the direction of some speed performance data, power settings and/or checklist for the BN2 Islander? I have been scouring all over the web but cannot find what I'm looking for.
Join Date: Nov 2005
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I have a POH and checklist you can PM me. I hope you've got a very good ANR headset!
Also here is a review of the features
Undaunted by aerodynamic reality, the design team at Pilatus/Britten-Norman has announced plans for the BN2-XL (Extra Loud), promising more noise, reduced payload, a lower cruise speed, and increased pilot workload.
We spoke to Mr. Fred Gribble, former British Rail boilermaker and now Chief Project Engineer. Fred was responsible for developing many original and creative design flaws in the service of his former employer, and assures he will be incorporating these in the new BN2-XL technology under a licensing agreement.
Fred reassured BN-2 pilots however that all fundamental design flaws of the original model had been retained. Further good news is that the XL version is available as a retrofit.
Among the new measures is that of locking the ailerons in the central position, following airborne and simulator tests which showed that whilst pilots of average strength were able to achieve up to 30° of control wheel deflection, this produced no appreciable variation in the net flight path of the aircraft.
Thus the removal of costly and unnecessary linkages has been possible, and the rudder has been nominated as the primary directional control. In keeping with this new philosophy, but to retain commonality for crews transitioning to the XL, additional resistance to foot pressure has been built into the rudder pedals to prevent overcontrolling in gusty conditions (defined as those in which wind velocity exceeds 3 knots).
An outstanding feature of Islander technology has always been the adaptation of the 0-540 engine, which mounted in any other aircraft in the free world (except the Trislander) is known for its low vibration levels, so as to cause it to shake and batter the airframe, gradually crystallise the main spar, desynchronise the accompanying engine, and simulate the sound of fifty skeletons fornicating in an aluminium dustbin.
Britten-Norman will not disclose the technology they applied in enhancing this effect in the XL, but Mr. Gribble assures us it will be perpetuated in later models and sees it as a strong selling point; "After all, the Concorde makes a lot of noise," he said, "and look how fast it goes."
However, design documents clandestinely recovered from the Britten-Norman shredder have solved a question that has puzzled aerodynamicists and pilots for many years, disclosing that it is actually noise which causes the BN-2 to fly. The vibration set up by the engines and amplified by the airframe, in turn causes the air molecules above the wing to oscillate at atomic frequency, reducing their density and causing lift. This can be demonstrated by sudden closure of the throttles, which causes the aircraft to fall from the sky. As a result, lift is proportional to noise rather than speed, explaining amongst other things the aircraft's remarkable takeoff performance. In the driver's cab (as Gribble describes it), ergonomic measures will ensure that long-term PBN pilots' deafness does not cause inflight dozing. Orthopaedic surgeons have designed a cockpit layout and seat to maximise backache, enroute insomnia, chronic irritability, and terminal (post-flight) lethargy. Redesigned 'bullworker' elastic aileron cables, now disconnected from the control surfaces, increase pilot workload and fitness.
Special noise retention cabin lining is an innovation on the XL, and it is hoped in later models to develop cabin noise to a level which will enable pilots to relate ear pain directly to engine power, eliminating the need for engine instruments altogether.
We were offered an opportunity to fly the XL at Britten-Normans' developmental facility, adjacent to the Britrail tea rooms at Little Chortling. (The flight was originally to have been conducted at the Pilatus plant, but aircraft of Britten-Norman design are now prohibited from operating in Swiss airspace during the avalanche season).
For our mission profile, the XL was loaded with fossil fuel for a standard 100 nm with Britrail reserves, carrying one pilot and nine passengers to maximise discomfort.
Passenger loading is unchanged, the normal under-wing protrusions inflicting serious lacerations on 71% of boarding passengers, and there was the usual entertaining confusion in selecting a door appropriate to the allocated seat.
The facility for the clothing of embarking passengers to remove oil slicks from engine cowls during loading has also been thoughtfully retained.
Startup is standard, and taxying, as in the BN-2, is accomplished by brute force. Takeoff calculations called for a 250 decibel power setting, and the rotation force for the (neutral) C of G was calculated as 180ft/lbs of back pressure.
Initial warning of an engine failure during takeoff is provided by a reduction in flight instrument panel vibration. Complete seizure of one engine is indicated by the momentary illusion that the engines have suddenly and inexplicably become synchronised. Otherwise, identification of the failed engine is achieved by comparing the vibration levels of the windows on either side of the cabin. (Relative passenger pallor has been found to be an unreliable guide on many BN-2 routes because of ethnic considerations).
Shortly after takeoff the XL's chief test pilot, Capt. "Muscles" Mulligan, demonstrated the extent to which modem aeronautical design has left the BN-2 untouched; he simulated pilot incapacitation by slumping forward onto the control column, simultaneously applying full right rudder and bleeding from the ears. The XL, like its predecessor, demonstrated total control rigidity and continued undisturbed.
Power was then reduced to 249 decibels for cruise, and we carried out some comparisons of actual flight performance with graph predictions.
At 5000' and ISA, we achieved a vibration amplitude of 500 CPS and 240 decibels, for a fuel flow of 210 lb/hr, making the BN-2 XL the most efficient converter of fuel to noise since the Titan rocket.
Exploring the constant noise-variable speed and constant speed-variable noise concepts, we found that in a VNE dive, vibration reached its design maximum at 1000 CPS, at which point the limiting factor is the emulsification of human tissue. The catatonic condition of long term BN-2 pilots is attributed to this syndrome, which commences in the cerebral cortex and spreads outwards.
We asked Capt. Mulligan what he considered the outstanding features of the XL. He cupped his hand behind his car and shouted. "Whazzat?"
We returned to Britten-Norman field convinced that the XL model retains the marque's most memorable features, while showing some significant and worthwhile regressions.
Pilatus/Britten-Norman are however not resting on their laurels. Plans are already advanced for the three-engined Trislander XL, and noise tunnel testing has commenced. The basis of preliminary design and performance specifications is that lift increases as the square of noise, and as the principle of acoustic lift is further developed, a later five-engined vertical takeoff model is another possibility.
Also here is a review of the features
Undaunted by aerodynamic reality, the design team at Pilatus/Britten-Norman has announced plans for the BN2-XL (Extra Loud), promising more noise, reduced payload, a lower cruise speed, and increased pilot workload.
We spoke to Mr. Fred Gribble, former British Rail boilermaker and now Chief Project Engineer. Fred was responsible for developing many original and creative design flaws in the service of his former employer, and assures he will be incorporating these in the new BN2-XL technology under a licensing agreement.
Fred reassured BN-2 pilots however that all fundamental design flaws of the original model had been retained. Further good news is that the XL version is available as a retrofit.
Among the new measures is that of locking the ailerons in the central position, following airborne and simulator tests which showed that whilst pilots of average strength were able to achieve up to 30° of control wheel deflection, this produced no appreciable variation in the net flight path of the aircraft.
Thus the removal of costly and unnecessary linkages has been possible, and the rudder has been nominated as the primary directional control. In keeping with this new philosophy, but to retain commonality for crews transitioning to the XL, additional resistance to foot pressure has been built into the rudder pedals to prevent overcontrolling in gusty conditions (defined as those in which wind velocity exceeds 3 knots).
An outstanding feature of Islander technology has always been the adaptation of the 0-540 engine, which mounted in any other aircraft in the free world (except the Trislander) is known for its low vibration levels, so as to cause it to shake and batter the airframe, gradually crystallise the main spar, desynchronise the accompanying engine, and simulate the sound of fifty skeletons fornicating in an aluminium dustbin.
Britten-Norman will not disclose the technology they applied in enhancing this effect in the XL, but Mr. Gribble assures us it will be perpetuated in later models and sees it as a strong selling point; "After all, the Concorde makes a lot of noise," he said, "and look how fast it goes."
However, design documents clandestinely recovered from the Britten-Norman shredder have solved a question that has puzzled aerodynamicists and pilots for many years, disclosing that it is actually noise which causes the BN-2 to fly. The vibration set up by the engines and amplified by the airframe, in turn causes the air molecules above the wing to oscillate at atomic frequency, reducing their density and causing lift. This can be demonstrated by sudden closure of the throttles, which causes the aircraft to fall from the sky. As a result, lift is proportional to noise rather than speed, explaining amongst other things the aircraft's remarkable takeoff performance. In the driver's cab (as Gribble describes it), ergonomic measures will ensure that long-term PBN pilots' deafness does not cause inflight dozing. Orthopaedic surgeons have designed a cockpit layout and seat to maximise backache, enroute insomnia, chronic irritability, and terminal (post-flight) lethargy. Redesigned 'bullworker' elastic aileron cables, now disconnected from the control surfaces, increase pilot workload and fitness.
Special noise retention cabin lining is an innovation on the XL, and it is hoped in later models to develop cabin noise to a level which will enable pilots to relate ear pain directly to engine power, eliminating the need for engine instruments altogether.
We were offered an opportunity to fly the XL at Britten-Normans' developmental facility, adjacent to the Britrail tea rooms at Little Chortling. (The flight was originally to have been conducted at the Pilatus plant, but aircraft of Britten-Norman design are now prohibited from operating in Swiss airspace during the avalanche season).
For our mission profile, the XL was loaded with fossil fuel for a standard 100 nm with Britrail reserves, carrying one pilot and nine passengers to maximise discomfort.
Passenger loading is unchanged, the normal under-wing protrusions inflicting serious lacerations on 71% of boarding passengers, and there was the usual entertaining confusion in selecting a door appropriate to the allocated seat.
The facility for the clothing of embarking passengers to remove oil slicks from engine cowls during loading has also been thoughtfully retained.
Startup is standard, and taxying, as in the BN-2, is accomplished by brute force. Takeoff calculations called for a 250 decibel power setting, and the rotation force for the (neutral) C of G was calculated as 180ft/lbs of back pressure.
Initial warning of an engine failure during takeoff is provided by a reduction in flight instrument panel vibration. Complete seizure of one engine is indicated by the momentary illusion that the engines have suddenly and inexplicably become synchronised. Otherwise, identification of the failed engine is achieved by comparing the vibration levels of the windows on either side of the cabin. (Relative passenger pallor has been found to be an unreliable guide on many BN-2 routes because of ethnic considerations).
Shortly after takeoff the XL's chief test pilot, Capt. "Muscles" Mulligan, demonstrated the extent to which modem aeronautical design has left the BN-2 untouched; he simulated pilot incapacitation by slumping forward onto the control column, simultaneously applying full right rudder and bleeding from the ears. The XL, like its predecessor, demonstrated total control rigidity and continued undisturbed.
Power was then reduced to 249 decibels for cruise, and we carried out some comparisons of actual flight performance with graph predictions.
At 5000' and ISA, we achieved a vibration amplitude of 500 CPS and 240 decibels, for a fuel flow of 210 lb/hr, making the BN-2 XL the most efficient converter of fuel to noise since the Titan rocket.
Exploring the constant noise-variable speed and constant speed-variable noise concepts, we found that in a VNE dive, vibration reached its design maximum at 1000 CPS, at which point the limiting factor is the emulsification of human tissue. The catatonic condition of long term BN-2 pilots is attributed to this syndrome, which commences in the cerebral cortex and spreads outwards.
We asked Capt. Mulligan what he considered the outstanding features of the XL. He cupped his hand behind his car and shouted. "Whazzat?"
We returned to Britten-Norman field convinced that the XL model retains the marque's most memorable features, while showing some significant and worthwhile regressions.
Pilatus/Britten-Norman are however not resting on their laurels. Plans are already advanced for the three-engined Trislander XL, and noise tunnel testing has commenced. The basis of preliminary design and performance specifications is that lift increases as the square of noise, and as the principle of acoustic lift is further developed, a later five-engined vertical takeoff model is another possibility.
HAD GREAT FUN, sorry, mustn’t shout – it’s the deafness you know – one day in an Islander taking off on a positioning flight with no pax and with fairly low fuel levels. On the day in question there was a cracking wind gradient building upon an already stonking headwind. On reaching approx. 1000ft agl, H ‘n’ H requested an “early right turn on track”. There was a distinct delay in the response as the ATCO was clearly “backtracking and levitating” his viewing point back from his anticipated location of me at the time of my call as there was nothing to be seen in his initial anticipated position – somewhere near the upwind end of the active. Eventually, by craning his neck sharply up, and looking level with the tower (set mid-field) rather than towards the upwind end of the 2800 ft runway, he located me almost above him – at which point, he then realised why the rather strange request! The response was “C/S, early right turn approved ………… so that’s how it’s done, eh!!!!!!!”. So, h88b, the “vertical take-off” BN dream is almost within the grasp of the 250dB take-off - given a bit of a breeze to help things along! :-)
I did about 500 hours on the Islander and I loved it to bits. Flying with the rear port door removed just about managed to raise the noise level to an acceptable maximum and it also improved the efficiency of the air-conditioning system (especially in winter) immensely. I can remember leaving Marseilles with a 45 knot Mistral blowing heading for Nantes. The only thing that saved the day was that I was able to use my gliding knowledge to use the wave system over the Massif to my advantage otherwise I would never have got there. Speedy, she was not, but she was as strong as a horse and great fun to fly.
h88b wins the internet 
Chapeau!
Chapeau!
Islander
Interesting attitude towards the BN2.
I think the clue is in the name ISLANDER.
This is not a high speed high flying long distance machine, but rather a twin engine pick up truck for 'hopping' short distances over the water, plus having to contend with the most basic of landing surfaces and distances.
The 'Twin' bit is required due to the regulations appertaining to public transport operations over water, and the twin it replaced was a fabric covered biplane that although in itself was a sterling provider of service could not continue indefinitely in that role.
To this must be added its 'multi role' ability (passenger-freight-passenger) in minutes, or a combination of both.
Yes a double layer window abeam the props would have been nice (and indeed modded by some) but when the wind is buffeting across a short wet strip and a job 'has' to be done then it does what it says on the tin, and all the drivers I know had great confidence in it not to mention the fun.
I think the clue is in the name ISLANDER.
This is not a high speed high flying long distance machine, but rather a twin engine pick up truck for 'hopping' short distances over the water, plus having to contend with the most basic of landing surfaces and distances.
The 'Twin' bit is required due to the regulations appertaining to public transport operations over water, and the twin it replaced was a fabric covered biplane that although in itself was a sterling provider of service could not continue indefinitely in that role.
To this must be added its 'multi role' ability (passenger-freight-passenger) in minutes, or a combination of both.
Yes a double layer window abeam the props would have been nice (and indeed modded by some) but when the wind is buffeting across a short wet strip and a job 'has' to be done then it does what it says on the tin, and all the drivers I know had great confidence in it not to mention the fun.
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May I make a small correction to Roger Bacon/h88b's amusing post. The Manifold Pressure gauges on the Islander were calibrated in dBx10. Take-off power on a good day, as long as family of sparrows hadn't nested in the induction manifolds, was 294dB, and economical cruise was as low as 200dB if you had all day and struggled up to FL80.
Had the pleasure of flying in Mustique Airways BN-2's many years ago, BGI-MQS-UNI-BGI (J8-VAN and J8-VAT).
I think POBJOY is spot on with his analysis. Sitting on a bench seat in a commercial aircraft....can this be bettered?! I can remember the "....watchout/duck/be careful...." briefing from the pilot before and after the flights
The UNI-BGI leg was at night, with tropical thunderstorms illuminating the surrounding night and the gentle glow of the cockpit lights providing the only real reference in the cabin. And yes the engines provided ample equalisation to deaden the effect of any thunderclaps
I have also had the pleasure of some Central American jungle flying in C208's and its not surprising to see why the later has been so successful in this class.
Sorry Pilot U no numbers for you, but thanks for the trigger of some happy memories.
I think POBJOY is spot on with his analysis. Sitting on a bench seat in a commercial aircraft....can this be bettered?! I can remember the "....watchout/duck/be careful...." briefing from the pilot before and after the flights
The UNI-BGI leg was at night, with tropical thunderstorms illuminating the surrounding night and the gentle glow of the cockpit lights providing the only real reference in the cabin. And yes the engines provided ample equalisation to deaden the effect of any thunderclaps
I have also had the pleasure of some Central American jungle flying in C208's and its not surprising to see why the later has been so successful in this class.
Sorry Pilot U no numbers for you, but thanks for the trigger of some happy memories.
Islander FUN
As an aside; when I speak to drivers that have been elevated to the higher flight levels (and very high with Concorde) they all look back to their BN2 days with a smile.
Not just because they were always 'solo'. but also because the nature of the operations gave them a great start in making decisions.
The Islander was in the same category as the C180/185 and the later Caravan in that it was fun to operate because of the nature of the tasks required.
The low speed handling was a great help when getting into limited strips in adverse conditions but I always thought the single engine performance was rather optimistic due to the load it was expected to carry. In practice (and especially in turbulent conditions) knocking a few hundred pounds off its Max permitted wt would ensure a positive single eng ROC, and therefore a reasonable safety margin. STOL aircraft are not always 'high flyers' but you never forget the experience of making it work for you. When operating off contaminated surfaces the pilot has to use judgement rather than (reading the numbers) and this is where the BN2 shows its mettle (its honest)
Not just because they were always 'solo'. but also because the nature of the operations gave them a great start in making decisions.
The Islander was in the same category as the C180/185 and the later Caravan in that it was fun to operate because of the nature of the tasks required.
The low speed handling was a great help when getting into limited strips in adverse conditions but I always thought the single engine performance was rather optimistic due to the load it was expected to carry. In practice (and especially in turbulent conditions) knocking a few hundred pounds off its Max permitted wt would ensure a positive single eng ROC, and therefore a reasonable safety margin. STOL aircraft are not always 'high flyers' but you never forget the experience of making it work for you. When operating off contaminated surfaces the pilot has to use judgement rather than (reading the numbers) and this is where the BN2 shows its mettle (its honest)
Last edited by POBJOY; 5th Nov 2017 at 19:02.
Pobjoy,
How right you are about the aircraft. (The version that I flew for some 12 years was known as the "Defender" (don't ask!!). However, it was one of the most enjoyable aircraft/tasks ever! (Never mind the fast jets etc. etc. in the RAF). Yes, noisy, shaking and all the rest but it did what you wanted!!
Bill
How right you are about the aircraft. (The version that I flew for some 12 years was known as the "Defender" (don't ask!!). However, it was one of the most enjoyable aircraft/tasks ever! (Never mind the fast jets etc. etc. in the RAF). Yes, noisy, shaking and all the rest but it did what you wanted!!
Bill
Islander FUN
Probably the most unusual 'uniform' I ever flew in was in the dear old BN2.
The task was an Island destination charter of Americans who also happened to be friends of the management.
Unknown to all I 'borrowed' a 'Disney' style Mickey Mouse outfit and when the flight was called led them out to the waiting machine (you can imagine the surprise that caused with the other people waiting for their flight)
The next surprise to the charter px was when 'Mickey' not only boarded them but then climbed in the front and gave them the brief.
Needless to say 'Mickey' could not actually see properly or wear a headset so had to remove his head for the flight, but this was soon replaced after landing and the happy band was led into the 'arrivals' with a suitable Disney wave, and gasps off delight from the terminal. No doubt another first for the BN2.
IT was damm hot in that outfit though !!!
The task was an Island destination charter of Americans who also happened to be friends of the management.
Unknown to all I 'borrowed' a 'Disney' style Mickey Mouse outfit and when the flight was called led them out to the waiting machine (you can imagine the surprise that caused with the other people waiting for their flight)
The next surprise to the charter px was when 'Mickey' not only boarded them but then climbed in the front and gave them the brief.
Needless to say 'Mickey' could not actually see properly or wear a headset so had to remove his head for the flight, but this was soon replaced after landing and the happy band was led into the 'arrivals' with a suitable Disney wave, and gasps off delight from the terminal. No doubt another first for the BN2.
IT was damm hot in that outfit though !!!
I was once told that running out pof fuel through anything other than battle damage resulted in a mandatory Court Martial. But where the PIC was of 1-star or above it was the fuel that was court martialed for being AWOL rather than the pilot for failing to notice its absence...
PDR
PDR
I believe the Acoustic Lift Technology is courtesy of Paul Phelan.
When I was flying them it was 65 knots for everything...
When I was flying them it was 65 knots for everything...