Flight test: Alou­ette II

Pre­dictable and vice-free − although very thirsty − the de­pend­able Alou­ette’s han­dling would suit a low-time pi­lot

Pilot - - CONTENTS - Words: Pat Malone Pho­tos: Keith Wil­son

Although el­derly, this heli­copter is vice-free and nice to fly but rather thirsty and needs a lot of grease!

Seventy years ago the French avi­a­tion com­pany Sud Est de­signed and built a heli­copter called the Alou­ette, and it was a bit of a dog. The cel­e­brated test pi­lot Jean Boulet wrung an im­pres­sive per­for­mance out of the pro­to­type when he set a world closed-cir­cuit dis­tance record of 675nm, but the com­pany knew it was in a blind al­ley−such odd­i­ties as twin tail ro­tors mounted on a V-shaped tail, and the lack of puff from a 200hp Salm­son pis­ton engine, meant that this par­tic­u­lar Alou­ette never went into pro­duc­tion.

So Sud Est de­cided to do some­thing re­ally rad­i­cal. They kept the pow­er­train and dis­carded al­most ev­ery­thing else, and most im­por­tantly they de­cided they were go­ing to make their old dog into the first pro­duc­tion heli­copter in the world with a tur­bine engine. At the time, this was far from a no-brainer. Tur­bines were tem­per­a­men­tal, used lots of fuel and had short lives and greedy main­te­nance ap­petites, and they were treated with sus­pi­cion by right-think­ing en­gi­neers. But Sud Est had to take a leap of faith to make their Alou­ette fly, and they de­cided to risk it.

They found what they needed in the premises of a Pol­ish refugee called Josef Syd­lowski, who’d been work­ing in Ger­many but had fled Nazi-era anti-semitism and taken his en­gi­neer­ing ge­nius to a lit­tle town called Saint-pé-de-big­orre in south­ern France. After the Ger­man in­va­sion he had fur­ther re­moved him­self to Switzer­land. His com­pany, which he called Tur­bomeca, ticked over dur­ing the oc­cu­pa­tion, and when the un­pleas­ant­ness was over Syd­lowski went back and be­gan to de­velop tur­bine en­gines.

The mar­riage of Sud Est’s air­frame with Syd­lowski’s engine−an it­er­a­tion he called the Ar­touste−cre­ated a phe­nom­e­non. The SE 3130 Alou­ette II made its first flight in 1955 and went on to be­come one of the best-sell­ing light he­li­copters ever made. In pro­duc­tion for twenty years, it was adopted by armies and air forces all over the world, had some suc­cess in the civil­ian field, set and broke in­nu­mer­able records and achieved the ul­ti­mate ac­co­lade when the Amer­i­cans asked to pro­duce it un­der li­cence; Repub­lic Avi­a­tion made a hand­ful, but they never re­ally took off in the States. The Army Air Corps in the UK bought sev­en­teen and, although the ma­chine was largely used for ob­ser­va­tion, li­ai­son and train­ing, sev­eral forces hung weapons on it, in­clud­ing anti-tank mis­siles and hom­ing tor­pe­does.

One of its most suc­cess­ful spin-offs was the SA315B Lama, a beefed-up beast with ex­cep­tional hot and high per­for­mance. In 1972−again with Jean Boulet at the stick−it set a heli­copter al­ti­tude record of 40,814 feet, which stands to­day. When Boulet re­duced power the engine flamed

out, so he set an­other record for the long­est au­toro­ta­tion.

In the civil­ian world the heli­copter has been put to ev­ery­thing from VIP trans­port to crop-spray­ing. Of the 1,300 Alou­ettes of all types built, there are said to be sev­eral dozen still in op­er­a­tion around the world. They’ve long been eclipsed by more mod­ern ma­chin­ery−the Aerospa­tiale Gazelle was their im­me­di­ate suc­ces­sor, Sud Est hav­ing been ab­sorbed into Aerospa­tiale− but they are kept aloft by en­thu­si­as­tic own­ers and pi­lots who don’t mind a bit of noise and hav­ing to grease nip­ples and fill the tank every five min­utes. One such is War­ren Davies, proud owner of N297CJ, which he keeps on a farm near his home in Al­ces­ter, War­wick­shire.

War­ren is a long-time fixed-wing pi­lot who used to race a Beech Baron and fly aer­o­batic glid­ers. He got his heli­copter li­cence in 2000 and bought an R22 in which he used to bravely com­mute to the Mid­lands from the Isle of Man in two and a quar­ter hours, much of it ob­vi­ously over wa­ter. He kept G-KUKI for only nine months and con­tin­ued his com­mut­ing in fixed-wings, but he’s al­ways been look­ing for some­thing a bit dif­fer­ent and when a friend showed him de­tails of the Alou­ette II his in­ter­est was piqued. “I’d never even seen an Alou­ette,” he said. “But the spec looked good, and what was es­pe­cially in­ter­est­ing was the price−£90,000, with a spare engine thrown in. That’s about what a run-out R44 would cost, and when you think you’d pay well into six fig­ures of money just for a Gazelle engine, it looks very at­trac­tive.”

The Alou­ette II was owned by Steve Ather­ton, a York­shire-based col­lec­tor of Aerospa­tiale prod­ucts, par­tic­u­larly Gazelles, who had found him­self with one too many. Man­u­fac­tured in 1963, it had flown for most of its life with the Ger­man Army Avi­a­tion Corps, the Heeres­flieger, be­fore be­ing trans­ferred to the Por­tuguese mil­i­tary in 1981. It was later sold to a civil­ian owner and put on the French reg­is­ter. After pass­ing through the hands of sev­eral French­men it was sold to the UK, placed on the N-reg­is­ter and kept at Red­hill. It came to Steve Ather­ton in time for him to fly it to France for the six­ti­eth an­niver­sary cel­e­bra­tions of the Alou­ette in France in 2015. With a cou­ple of sparkling Gazelles in his hangar Steve wasn’t fly­ing N297CJ much, and was happy to let it go to a good home.

The Alou­ette II looks like the front end of a Gazelle stuck onto a sec­tion of Bai­ley bridge, with a big−very big−fuel tank in the mid­dle and a lit­tle engine popped on top. It sits very low on re­ally busi­nesslike skids and is clearly hewn from proper gird­ers. It is in fact the front end of a Gazelle; its suc­ces­sor took the cabin un­mod­i­fied from the Alou­ette. The tail trel­lis is of alu­minium tub­ing filled with pres­surised ni­tro­gen;

Of the 1,300, there are said to be sev­eral dozen still in op­er­a­tion

there are two tell-tales that change colour if the ni­tro­gen pres­sure drops, in which case you’d wisely sus­pect a crack.

The doors are huge, run­ning al­most the en­tire length of the cabin, and with the fuse­lage sit­ting so low it must be the eas­i­est light heli­copter in the world to climb into. Be­low the main ro­tor gear­box is a truly hu­mungous bath­tub of a fuel tank which is said to hold 580 litres of Jet-a1. War­ren thinks it’s ac­tu­ally only 575, but given that the heli­copter burns through 180 litres an hour even at a nice sen­si­ble cruise set­ting, you need some­thing that holds a lot. The Ar­touste engine was de­signed to run on al­most any­thing that would burn, the idea be­ing that in wartime you could land and siphon off what­ever was avail­able.

The blades have a light al­loy spar and are filled with syn­thetic resin foam, and they can be folded for ease of stor­age. War­ren be­lieves they’ve been fixed in place all the air­craft’s life, and even though the fold­ing ex­er­cise is said to be quite sim­ple−just pull out a cou­ple of pins out­board of the drag dampers−he wouldn’t dream of try­ing to fold them. As well as the dampers, the head also fea­tures stout spac­ing ca­bles.

There are sight glasses ev­ery­where you’d ex­pect to find oil, and top­ping off the var­i­ous fillers, some­thing that must be done reg­u­larly, is not a big job− they’re all un­ob­structed and easy to get at. At the bot­tom, just be­hind the cabin, you can see the con­trol runs turn­ing up to the ro­tor mast, and the wheel that’s ac­ti­vated by a push-rod from the ped­als; around the wheel is a dual ca­ble that runs through a se­ries of guides to the tail ro­tor pitch change mech­a­nism.

Around the jet­pipe there’s a heater sleeve con­nected to the cabin by a se­ri­ously big pip­ing sys­tem that goes up hill and down dale be­fore con­nect­ing to in­ter­nal over­head dis­trib­u­tors. A heli­copter with so much Per­spex would need an ef­fi­cient heater for demist­ing on damp days, but the weight must be sig­nif­i­cant−couldn’t they find an­other way? I sup­pose with a 530hp engine haul­ing a heli­copter that weighs al­most a tonne empty, a bagatelle like this mat­ters less… On the side of the fuse­lage is a small han­dle that turns the heater from ‘purge’ to ‘on’. The engine is sup­posed to be started in ‘purge’ mode, so if you’re on your own, you’re go­ing to have your hands full switch­ing on the heater.

The tail ro­tor drive shaft runs along the top of the boom through four in­ter­me­di­ate bear­ings, each with a grease nip­ple. A lot of greas­ing needs to be done on this ma­chine, and given that he­li­copters do what they do, it gets spread lib­er­ally about. The tail ro­tor pitch change mech­a­nism is ac­ti­vated by a screw-thread ar­range­ment around which the pedal ca­ble runs, and there’s a gear­box that needs to be kept

topped off with oil. The tail ro­tor blades flap in­de­pen­dently over a sur­pris­ingly large arc, and there are two hor­i­zon­tal sta­bilis­ers of neu­tral air­foil sec­tion. There’s no ver­ti­cal sta­biliser but there’s a large steel loop be­low the boom to pro­tect the tail. Given the lowslung na­ture of the heli­copter I was par­tic­u­larly con­scious not to catch the guard by flar­ing too low.

Those mas­sive doors con­trib­uted to the ver­sa­til­ity of the heli­copter in ser­vice−you can get a stretcher across the back, or sev­eral pairs of skis. There are two catches to hold the doors open, and they’re re­leased by small han­dles that fall eas­ily to hand when you’re in the driver’s seat−un­like the door han­dles them­selves, for which you must reach way, way back be­hind you.

View is fab­u­lous all round, although the door frame is at eye level and I found that I couldn’t for­mate on the cam­era ship with­out lean­ing for­ward or back, so you’d have to be con­scious of a blank spot. The con­trols are where you’d ex­pect, with the ped­als be­ing ad­justable by turn­ing over the foot bar. The cyclic on CJ has a cou­ple of re­dun­dant switches that might once have pick­led a load or even fired a TOW mis­sile, but all that works now is the PTT. The bin­na­cle is au­then­tic 1960s, although a sub­sidiary panel in which an ar­ti­fi­cial hori­zon was once set now houses an 8.33 ra­dio. At the top of the main panel you’ve got a big red fuel flow light that comes on when you’re de­mand­ing too much of the engine and thus over­pitch­ing. There are warn­ing lights for trans­mis­sion and engine oil pres­sure, fuel pres­sure and fuel fil­ter re­stric­tion. At top left is the ASI, with a 105kt red­line, VSI next to it, and ro­tor and engine RPM gauge at top right. Next row is, on the left, com­bined Tur­bine Out­let Tem­per­a­ture (TOT), engine oil pres­sure and tem­per­a­ture; al­time­ter; and col­lec­tive pitch in­di­ca­tor, with a red line at 14.5 de­grees. You can heave the lever through this to nine­teen de­grees in ex­tremis, but you’ll cer­tainly be dic­ing with the fuel flow warn­ing light. On the bot­tom, be­low the ro­tor brake, there are elec­tri­cal

You can get a stretcher across the back, or sev­eral pairs of skis

and air pres­sure mon­i­tors, plus a fuel gauge which, War­ren points out not in­ac­cu­rately, acts like a rev counter in re­verse. In­ter­est­ingly, there’s no way you can dip the tank, so you’d best watch the stuff go­ing in.

At the bot­tom of all this there’s a guarded ‘start’ but­ton, and three tog­gle switches for fuel boost, genny and batt, with as­so­ci­ated warn­ing lights. In the quad­rant be­low the bin­na­cle there are three levers−on the left, the emer­gency fuel shut-off, wire locked for the dis­cour­age­ment of in­ap­pro­pri­ate use. Then there’s the gover­nor lever – ap­par­ently you can use this to tweak the engine revs down­ward by about 1,000 in the cruise for econ­omy, but it makes

lit­tle dif­fer­ence and there’s a plas­tic plug to stop it mov­ing. On the right is the power lever, marked ‘throt­tle’, no doubt to the fury of purists.

Sur­pris­ingly (to me, any­way) the engine was ridicu­lously easy to start. If you’re used to the three­handed split-brain se­quence of some­thing like a six­ties Al­li­son in a Je­tranger, you’ll be an in­stant con­vert to the French Way. First, check to see you’ve got a blade at twelve o’clock. If you haven’t, you’ll be bar­be­cu­ing one on the jet pipe, so get out and sort it. Ro­tor brake off, batt on, CBS in, fuel on, flick the fuel boost on for thirty sec­onds. Lift the guard and switch the starter to ‘on’. Lights will il­lu­mi­nate as the starter spools up−red when the starter re­lay is en­gaged, and orange at 4,000 revs when the flame ig­niter mi­crop­ump comes on. Watch the TOT, which is red-lined at 550 de­grees; on this day it didn’t get much above 450 be­fore fall­ing back, and War­ren tells me he’s never seen it hit 500. The engine is self-sus­tain­ing at the 12,000rpm idle set­ting, and a green light tells you you’re in busi­ness. And that’s all there is to it.

The noise level is fairly high, and the high­est-pitch tur­bine whine in­trudes through the ANR head­sets, although it’s never un­com­fort­able and you can ac­tu­ally make your­self heard with­out a head­set on−i wouldn’t rec­om­mend it for long, through. Work the ‘throt­tle’ gen­tly up to 23,000 revs, dip­ping it quite sharply in the early stages in or­der to en­cour­age the clutch to kick in. Carry on to 28,000rpm, fric­tions off, throt­tle to 34,000 revs, by which time ro­tor rpm should be get­ting up to­wards 350rpm. Throt­tle fi­nally to the gate, and you’re ready to roll.

See if you have a blade at twelve o’clock. If you haven’t, you’ll be Bbqing one on the jet pipe

Vi­bra­tion lev­els are quite re­mark­ably low. The head is well bal­anced and there’s no ap­pre­cia­ble buzz at all from the engine; the bin­na­cle re­mains rock steady. Lights out, Ts and Ps good, and lift the lever. CJ suf­fered a lit­tle from a crotch­ety lever− War­ren thinks the fric­tion sys­tem may not be fully dis­en­gag­ing and is get­ting it fixed−but oth­er­wise the con­trols were sen­si­tive to the point of frisk­i­ness. Only the cyclic is boosted, but tail ro­tor author­ity seems mar­vel­lous, and the light­est touch was needed on the ped­als. Fly­ing out of balance, as one does when hav­ing one’s pic­ture taken from an­other heli­copter, was a sim­ple ex­er­cise.

With two POB and an al­most­full tank we hov­ered at 13 de­grees on the col­lec­tive and climbed out at 14 de­grees. Best rate of climb is 50 knots, so I used 55 for climb­ing and de­scend­ing. She may weigh a tonne, but CJ han­dles well−not as squir­relly as small pis­ton he­li­copters but in­stantly re­spon­sive to small con­trol in­puts. In level flight at 13 de­grees we set­tled out at 90 knots, and the lack of vi­bra­tion is truly im­pres­sive. You can put the power to work by climb­ing zero-speed at 2,000fpm or more, but the over-rid­ing thought is for fuel flow, which must be well north of 200 litres an hour dur­ing hard work. She comes down as fast as she goes up, set­tling out at around 2,200fpm in au­toro­ta­tion, and with that big heavy ro­tor head there’s all the time in the world to flare off speed and rate of de­scent for the land­ing. The ro­tor speed range is mas­sive−min­i­mum is 280 and max­i­mum 450. Steep turns were pre­dictable, with lit­tle ten­dency for the pitch to change, but an in­ter­est­ing fea­ture was a vi­bra­tion that arose dur­ing de­cel­er­a­tion, par­tic­u­larly at low speeds−the tran­si­tion to the hover was ac­com­pa­nied from around forty knots to twenty knots by an air­frame shake that is all the more sur­pris­ing, given the lack of

vi­bra­tion in other regimes of flight. Wind di­rec­tion seemed im­ma­te­rial. I’ve since ques­tioned pi­lots with ex­pe­ri­ence on type about this, and they say “they all do that, sir”.

After land­ing, the throt­tle was re­tarded to 28,000rpm for one minute, then closed all the way with the fuel boost off. Starter switch goes to the off po­si­tion at this point. Ro­tor brake can be ap­plied at 170rpm but we were con­tent to let it set­tle in its own time−and again, there was no ‘pad­ding’.

‘On con­di­tion’ op­er­a­tion

It’s 64 years since the Alou­ette II first flew. Sud Est dis­ap­peared into what be­came Air­bus He­li­copters, and Tur­bomeca be­came Safran, one of the big beasts of the Euro­pean tur­bine world−and both owe their suc­cess to the foun­da­tion laid by the Alou­ette.

The Alou­ette II is a tur­bine with the sort of han­dling char­ac­ter­is­tics that make it suit­able for a rel­a­tively low-time pi­lot. Pre­dictable and vice-free, it rep­re­sents an easy step up from a ba­sic trainer. Mov­ing from the joys of own­er­ship to the de­spair of pay­ing for stuff, you’d have to say that the break you get on the pur­chase price could well be com­pen­sated for by the thirst of the beast. But fur­ther in its favour, ev­ery­thing is on-con­di­tion so it costs noth­ing to look at it sit­ting on the ground. Spares are not hard to come by, I’m told. I’m still go­ing to buy a 109 when my num­bers come up, but I could see my­self get­ting an Alou­ette too, for the sheer hell of it.

ANTI-CLOCK­WISE FROM TOP: air­craft struc­tures do not come any sim­pler than the Alou­ette’s ‘tail trel­lis’; skid strut shock ab­sorber; ‘hu­mungous bath tub’ of a fuel tank, symp­to­matic of the thirst of the Ar­touste tur­bine (note the cabin heater duct­ing!)

CLOCK­WISE FROM LEFT: the ca­ble-braced ro­tor blades can be folded – some­thing owner War­ren Davies says he’s never dared to try; sight glasses ev­ery­where there is oil to be kept topped up; the ni­tro­gen pres­sure tell-tale (if it shows red, you’ve a cracked frame tube); ca­bles and pul­leys all out in the open, where they are read­ily in­spected; and one of many grease nip­ples to be at­tended

ABOVE: the Aloutte’s cabin de­sign looks like a Gazelle’s be­cause it was car­ried through to its younger sib­ling

LEFT: next to the col­lec­tive (white grip) are levers for emer­gency fuel shut-off, gover­nor and ‘throt­tle’

ABOVE: cabin ven­til­la­tion and demist­ing are things to be taken very se­ri­ously in he­li­copters, where an un­in­ter­rupted view is ab­so­lutely es­sen­tial. The ro­tor brake, which can be ap­plied once it has slowed to 170rpm has its own fric­tion lock and is mounted over­head

ABOVE: Trig 8.33 ra­dio and transpon­der oc­cupy the space once taken by the AI

ABOVE: while the panel is sited where both in front can see the flight in­stru­ments, the es­sen­tial switchgear, ra­dios and GPS screen are all po­si­tioned to suit the pi­lot in com­mand seated, in heli­copter convention, on the right. That panel clock is a di­rect de­scen­dant of the Jung­hans J30BZ used in WWII Luft­waffe air­craft

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