Jump to content

The BN2 Islander, a plane best forgotten?


Recommended Posts

For many years as a parachute pilot , i would be asked to stand in for the pilot of the Red Devils Islander, I t was a plane I was checked out on so all was above board. however it was sooooo noisy it became quite well known as 50,000 rivets vibrating in unison, and if they stopped vibrating the plane would not fly. The jokes were legion, as a plane to fly it was quite benign but as a pilot you looked to the left and the prop was about 6 inches away from your ear and no amount of noise cancelling headphone could drown out that row.

 

Whilst researching my father for the Battle of Britain monument with the creator of the monument last week , he happened to be researching another BOB pilot who survived the war only to be killed test flying one of the early islander prototypes, and whilst talking to family friends etc he was given this tongue in cheek article

 

 

 

 

          Undaunted by technical realities, the design team at Pilatus Britten - Norman has announced plans for the BN2-XL, 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 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 degrees of control wheel deflection, this produced no appreciable variation in the net flight 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 in to the rudder pedals to prevent over-controlling 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 O-540 engine which, when mounted in any other aircraft in the free world (except the Trislander) is known for its low vibration levels. The Islander adaptations 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. PBN will not disclose the technology they applied in preserving this effect in the XL but Mr. Gribble assures us it will be perpetrated 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 that goes."

However design documents clandestinely recovered from the PBN shredder have solved a question that has puzzled aerodynamicists and pilots for many years, disclosing that it is actually noise which causes the BN2 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 creating 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 in-flight dozing. Orthopaedic surgeons have designed a cockpit layout and seat to maximise backache, en-route 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-Norman's development facility, adjacent to the British Rail tearooms at Little Chortling. (The flight was originally to have been conducted at the
Pilatus plant but aircraft of BN design are now prohibited from operating in Swiss airspace during avalanche season). For our mission profile, the XL was loaded with coal for a standard 100 N.M. trip with British Rail 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 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 been thoughtfully retained.

Start-up is standard, and taxiing, as in the BN2 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 at 180 ft/lbs. of backpressure.

Initial warning of an engine failure during takeoff is provided by a reduction in vibration of the flight instrument panel. 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 BN2 routes because of ethnic consideration).

Shortly after takeoff the XL's chief test pilot, Capt. Mike "Muscles" Mulligan demonstrated the extent to which modern aeronautical design has left the BN2 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 ft and ISA, we achieved a vibration amplitude of 500 CPS and 240 decibels, for a fuel flow of 210 lb/hr, making the BN2-XL the most efficient converter of fuel to noise after the Titan rocket.

Exploring the Constant noise/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 BN2 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 ear and shouted "Whazzat?"

We returned to Britten-Norman convinced that the XL model retains the marque's most memorable features, whilst showing some significant and worthwhile regressions.
PBN are not, however, resting on their laurels. Plans are already advanced for the Trislander XL and noise tunnel testing has commenced. The basis of preliminary design and performance specifications is that lift increases as the square of the noise, and as the principle of acoustic lift is further developed, a later five-engined vertical take-off model is also a possibility."

  • Like 2
Link to post
Share on other sites

Great one !  :)   As a regular BN2 Islander flyer (and former regular passenger, luckily for short 35 mns flights), I must admit that the possibility of reducing the engine sound to 17-18 in FSX settings allows me to sometimes understand what the ATC is telling me...

Link to post
Share on other sites

Possibly all quite true Nigel but I understand that it was and probably still holds the record as the UK's best selling aircraft. I saw plenty of them in the boondocks of SE Asia.

 

As it comes from the place I was born, the IoW, it holds a special place in my heart and if I'm in the mood for some low and very slow it's marvellous.

 

The Flight 1's Islander has captured all the above characteristics perfectly.

 

Great post though Nigel. :thum:

Link to post
Share on other sites

nice vid Al,

I defy anyone to do a soft landing at St Mary's there is always a little curler that dumps you uncerimoniously on the terra firma, you can hear the pilot increasing the revs to reduce the rate of descent the closer you got, mind you he was a bit low all the way in but hell thats just being picky, that little airfield has caught lots of pilots out over the years.

  • Like 1
Link to post
Share on other sites

I rest my case. The above vids show what a rugged little terrier it is, from the Scottish Islands to the Great Barrier Reef this workhorse,(or welsh pit pony) of a plane shows it's mettle. It's simple, no frills, easy to maintain, its USP, bit like a 2CV eh Nigel? and it ain't pretty. So what? No soundproofing, more payload, lands on a sixpence, takes off on a shilling, worth every penny.

 

A plane best forgotten? Not to anyone who flew in one.   :)

Link to post
Share on other sites

I rest my case. The above vids show what a rugged little terrier it is, from the Scottish Islands to the Great Barrier Reef this workhorse,(or welsh pit pony) of a plane shows it's mettle. It's simple, no frills, easy to maintain, its USP, bit like a 2CV eh Nigel? and it ain't pretty. So what? No soundproofing, more payload, lands on a sixpence, takes off on a shilling, worth every penny.

 

A plane best forgotten? Not to anyone who flew in one.   :)

 

oh they are rugged m8 ,no argument there,  however to own one privately will bankrupt you. they are hellishly expensive to ,operate , rather than bore the other persons here i am willing to give you some examples via PM.

they do have reasonably benign stall characteristics but they are not benign like a cessna for example , ignore the warnings and abuse the situation and you are in pawn, the islander like any other British a/c will give you a massive wing drop that takes more than a thousand feet to recover from.

 However like you I do look at them with a soft eye after all they are British , What?

another plane I look at similarly was the avro 748, which in my youth I thought was a trailblazer, especially for rough runways, British !! fly the flag!!  dont you know!!! 

but having flown one a few times albeit RHS and have a load of friends who have many many hours in them , the only conclusion is that it was not very good at all, unless you have fat purses like british airways had, they nearly bankrupted every airline they flew for, sad but true! they hot started for a living and were way overconstructed and overweight (how many times have we heard that levelled at british planes????)

that is why its replacement the ATP didnt sell well. the commonwealth had shrunk and those that had left, felt less inclined to buy british  hence planes like the saab 2000 sold well. So where has that left uk a/c production?

They did produce the islander in Romania but they had 100,000 rivets that vibrated loose, i have flown the turbine islander that the red devils now use and that is much quieter, their first turbine islander had lycoming turbines that were hellishly powerful after take off you aimed it at the blue , it would give an F16 trouble to 4000 feet , the problem was after kicking out the pasengers it was very easy to over cool the engine on descent entailing many hot end changes which is v expensive so they retro fitted the allsions which seems an agreeable marriage.

 

Link to post
Share on other sites

I remember years ago at the Greenham Common Air Show watching a demo flight. the aircraft taxied to the side of the runway, then took off across it! Much to the astonishment of a couple of USAF officers who were standing next to me!

Going back to the flight though, It remains the only scheduled airliner that I've ever flown it where the are signs above the windows saying "DO NOT OPEN IN FLIGHT!"

Link to post
Share on other sites

I have to admit to being a bit confused by the first video. The plane was pretty much on the ground during the entire approach (what? maybe 500 ASL?) so the runway appeared as a bit of a surprise. Then it occurred to me that the pilot had actually chosen a heli pad - the roundish bit. He then proceeded to brake on the taxiway, run out on the golf club lawn and stop in the carpark. Where is this place???

 

I flew in one of these aircraft down in the Caribbean. St Lucia to somewhere. It must have been fairly benign because the flight doesn't stand out as memorable - just successful.

 

Much fun, Nigel. Thanks for sharing. 

Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...