Lani sta Slovenijo in Ministrstvo za obrambo obiskala astronavtka Sunita Williams ter general Frank Gorenc. Oba potomca Slovencev, ki so se izselili v ZDA, sta dokazala, da s pridnim delom in vztrajnostjo lahko uspeš. Decembra smo objavili intervju s Sunito Williams, tokrat pa smo pripravili intervju z generalom Frankom Gorencem, ki je avgusta lani postal poveljnik zračnih sil Nata in hkrati poveljnik ameriških zračnih sil v Evropi ter Afriki. (interview with Frenk Gorenc in English)

Modern airports allow passengers to pass rapidly through terminals and board aircraft via boarding bridges. In these cases the aircraft are parked with their noses right up against the airport building. In order to reach this position on arrival or return to the apron centreline, from where they can continue under their own power, on departure, aircraft are assisted by special aircraft tow vehicles that are known in technical jargon as “pushback tractors”. Tudi v slovenščini

At Ljubljana Airport, which is also the home of Adria Airways, aircraft pushback operations are carried out by four vehicles that differ in terms of weight and engine power – and therefore the total weight they are capable of moving. The most powerful vehicle is a Schopf F300, which is capable of moving aircraft with a maximum take-off weight of up to 400 tonnes and costs half a million euros. It weighs an impressive 43 tonnes and its 173 kW engine can power it to a maximum speed of 30 km/h. The heaviest aircraft it has towed to date is an Antonov An-124, which has a fully laden weight of 400 tonnes. The ground handling service at Ljubljana Airport has 21 trained aircraft pushback operators who work in three teams. On average they carry out around 20 aircraft pushbacks each day: slightly fewer in winter and more (up to 25) in summer. They also look after those aircraft that need to be moved from the apron to hangars or other parking spaces.

Once all passengers have boarded an aircraft, the loading of baggage, freight and mail has been completed and all ground handling vehicles have withdrawn to a safe distance, the captain or first officer requests the airport control tower for permission to start the engines and move the aircraft back from the terminal building. Pushback is carried out by a ground crew team consisting of a “ramp agent” and a tractor operator. The drawbar can be attached to the aircraft once passenger embarkation or disembarkation is complete and the steering bypass has been engaged, meaning that the aircraft's nose wheel is now controlled externally. The drawbar attachment and drawbar itself differ for different types of aircraft (aircraft type and weight, specific restrictions). After attaching the drawbar to the aircraft's nose gear, the operator attaches the other end to the towing tractor and, with the permission of the person in command of the aircraft, removes the chocks from the aircraft's wheels. He then waits for the signal from the ramp agent, who first checks that the area around the aircraft is clear and then talks to the pilot via the intercom. The tractor operator is advised by the operator in the ground handling service's technical centre that the aircraft is cleared to move and then waits for the signal from the ramp agent, who unclenches his fist to signal that the operation can begin. The tractor operator switches on rotating red warning lights, to show that the pushback operation is now under way. As soon as the aircraft is cleared to move from its position, the aircraft's crew switch on the anti-collision lights – flashing red lights on the aircraft's fuselage – which sends a clear message to everyone on the apron: “The aircraft is about to move. Keep your distance!” Pushback follows the planned curves of the taxiways. In the case of a non-standard pushback, Ground Movement Control (GMC) communicates with the tractor operator and gives instructions on where to move the aircraft.

Usually pushback is from the parking position to the centreline of the apron, from where the aircraft can continue under its own power in accordance with GMC instructions. During the pushback operation the ramp agent controls the thrust of the aircraft's engines. When pushback has been completed, the ramp agent first uncouples the tractor from the drawbar. He then detaches the drawbar from the aircraft's nose gear and re-attaches it to the tractor, and restores control of the nose wheel to the aircraft's crew. The pushback tractor then moves out of the taxiway safety zone. This concludes the pushback operation. The duration of the operation depends on the complexity of the procedure but on average pushback takes between 3 and 6 minutes.

The movement of aircraft is carried out according to precisely defined instructions and procedures laid down by the responsible airport services, air traffic control and aircraft manufacturers. If this were not the case, there could be a risk of damage to the aircraft (the nose wheel) or airport equipment (such as the draw bar) or even a risk of collision with another aircraft or with a ground handling vehicle. According to pushback tractor operators, it is easier to move large aircraft because they are more stable and it is easier to see what is happening. Apparently they also handle better during pushback.

Text and photographs: Borut Podgoršek

V tej rubriki predstavljamo letališke službe.

✈ Vozila za vleko letal - Tow tractors

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Modest, unassuming, but extraordinary in all respects, Sunita Williams is one of the many descendants of Slovenians who went abroad to realise their dreams. However, the dreams of the parents have been fulfilled primarily by their children, Sunita being one of them. This year, she visited Slovenia for the second time. She also visited the Ministry of Defence. She presented her outstanding achievements, which are plenty, to Slovenians. Nobody was left indifferent.

Today, Sunita is the Director of Operations Russia in the Star City near Moscow. In that capacity, she runs an office which provides all the logistics for the US, European, Japanese and Canadian crewmembers training in Star City and who are preparing to go to space.
Tudi v slovenščini

How did work and book of Herman Potočnik Noordung The Problem of Space Travel - The Rocket Motor from 1928 influenced the development of space traveling and living in space?

I can’t exactly tell you from a historical perspective, but I am sure it was a huge influence on the first individuals who designed spacecraft.  As a visionary, Noordung’s influence has been realized in many rocket and space ship designers plans.

You have been in Cultural Centre of European Space Technologies in Vitanje? In your opinion how can we bring space and living in space to ‘normal’ people and vice versa?

Certainly!  Thru the center and the work that is going on with the International Space Station, we are hoping to share the visionary ideas and the actual scientic events that are occurring to help bring the concept of space and space travel into the household of all humans.  Lots of work in this field is out there for the public and one goal would certainly be to get as many people involved to tap into their new and creative ideas.

How can this center contribute to conquer the space, the universe?

The center is a great place as a museum and a center for advanced thought. The atmosphere of the place allows people to open their minds like Noordung did.  Creativity and imagination is the next step in advancement.  In the words of Albert Einstein, knowledge is useless without an imagination.

Would you go to the Mars? And what would you miss most?

Sure I would go to Mars. With today’s technology it would be a long trip, and we have a lot of work to ensure the crews are safe from radiation and micro gravity induced issues on the human body.  However, I think before long we will have the knowledge and technology to solve those problems.  Advancements in propulsion will be needed to send people further out to the reaches of our solar system for sure.  I think that might take a bit longer, but it WILL happen eventually.  I think the things that we miss about earth and unique to earth – our air, wind, ocean, water, other living beings that we know.  So, some memories of all these things of course would be important.  Specifically family and a sense of connection with earth thru pictures or some media would be of high importance to me.

What are you doing at present?

As an experienced ISS, Shuttle and Soyuz crewmember, I am also part of many working groups that interact with our Russian counterparts, to include Soyuz technical support – launch, rendezvous and landing - , EVA (spacewalk), Crew equipment, clothing and food, training planning, etc.  So every aspect of training and working with our Russian counterparts I seem to get involved in…funny, but it is overarching, and certainly fun, never boring.

Do you believe that there is another inhabited planet somewhere?

Absolutely.  There are millions of stars in the universe that we know.  Of course there has to be a star that is somewhat similar to our sun, which has planets that may possible be a distance that would sustain the atmospheric conditions to contain life.  Maybe not exactly as we know it, but even here on earth we are discovering new species living in very different environments, like at the bottom of an ocean in what we considered toxic gases.  So, more than likely yes.

Will Earth in 2100 still be the green planet or we will have to move?

That is a great question.  I think only we can do as much as we can to sustain life here.  Then of course there is always the possibility of us getting hit by some sort of asteroid that would change the landscape of the planet.  Nature is by nature very balancing.  When things get out of balance, it seems that generally our planet takes care of it.  However very fast change from humans is tough for our planet to keep up with. I think we all must think about how we can conserve and help our planet as much as possible and possibly slow down dramatic changes that would change our atmosphere for example. If we as humans want to remain here.

What was your first impression when seeing the Earth from the space and feel the 0g?

Incredible.  The planet is simply beautiful and alive and peaceful.  I wonder at how lucky we are to be on this planet and how we as humans all should see this view and then I am sure we would all be nicer to each other.

What does it mean cancellation of Space shuttle program for future? Does NASA have near future plans to built new vehicle or you will rely on Russia and their transport capabilities?

NASA is building a new vehicle to hopefully take us out of low earth orbit.  The space shuttle was an amazing vehicle and it was absolutely needed for us to build the International Space Station.  However, we now would like to go further than low earth orbit – someplace that doesn’t necessarily have a runway to land on – like the moon or Mars.  So we need a vehicle that can land under a parachute or with landing jets.  We are working on that future vehicle which will safely transport people further and return them.  It is the next good logical step in exploration.  In the meantime, our Russian counterparts are helping us out by transporting humans to the ISS.  We should have commercial providers, just like the airline industry which will soon take over that function of delivering people to low earth orbit alongside the Russians.

You have been launched also with Soyuz. What was the main difference compared to space shuttle launch?

Both are essentially the same.  Except the shuttle uses solid rocket booster primarily for the first stage.  The Soyuz uses all liquid engines in distinct stages for each propulsion to space.  However, both rides are about the same amount of time, dictated by physics and both spacecraft are made to be the home to humans in space.  They have different seats, but that is primarily for the landing phase of flight.

What do you think about privat companies like SpaceX, Orbital Science Corporation?

I think they are great.  With them, there will be competition for the job to take humans to low earth orbit.  With competition we will have a vehicle to do that job before long.  There is a lot of young, new innovation with these new companies. I love their work ethic and their enthusiasm.

How would you rate Pipistrels achievements in NASA competitions? You visited Pipistrel.

Pipistrel is a wondering company. I love that their work is so innovative. They are really guiding the way of future general aviation. Their ideas and way of working is so clean, precise and elegant.  This is the way our future will advance – thru technology that is good for our planet.  I had a wonderful time visiting with the folks who work at Pipstrel, and I feel they are a family.  They care about each other as well as their product.  Cooperation, sharing ideas is the way of the future.

What does it mean to you the medal of merit which you got from the president of Republic of Slovenia?

The award and everything that it means was totally humbling.  There are so many people and events which occurred to get me into space that I can only say that the award is really for all of them too.  Of course my parents are a huge influence on me, so this award is really for them.  I have had the opportunity to be taught by so many amazing people from elementary school to test pilot school.  This award is for them.  I have also worked alongside many international partners preparing for my spaceflights, this award is also for them.  I just hope I am representing all of these people, their commitment, dedication and professionalism, to merit such a great honor.

What do you think about Slovenia and Slovenians?

Slovenia and Slovenians are awesome!  I love the country.  I feel at home there for both of those reasons.  The people are as warm and inviting as the landscape.  I love the natural feel of the country and pride that the people who live there take in keeping it that way. I think Slovenians really understand what the meaning of preserving our planet is.  They love and appreciate nature and love to be part of it.  I am very pleased to be from a place on the planet that epitomizes these ideas and ideals.

Author of the interview Borut Podgoršek and Sunita Williams on the left photo

Foto: NASA, UPRS, MORS, Reuters

On 20 November 2013, the International Space Station (ISS) celebrated the 15th anniversary of the launch of its first module to space. The station was jointly built by five space agencies. It is divided into the Russian and American parts, which are used by several countries. The ISS is used as a research laboratory carrying out experiments in biology, physics, meteorology and other sciences. Sunita Williams has been on the ISS twice and was the second woman to become commander of the ISS.

Skromna, neopazna, toda v vseh pogledih izjemna Sunita Williams je ena izmed mnogih potomcev Slovencev, ki so odšli v svet, da bi uresničili svoje sanje. No, sanje svojih staršev so uresničili predvsem njihovi otroci, med katerimi je tudi Sunita.

Letos je drugič obiskala Slovenijo, gostili pa smo jo tudi na Ministrstvu za obrambo. Svoje izjemne dosežke, ki jih je kar nekaj, je predstavila Slovencem, tudi Urši, Romani in Andreji. Nikogar ni pustila ravnodušnega. Danes je Sunita Williams vodja operacije Rusija v Zvezdnem mestu (Star City) pri Moskvi. V tej vlogi vodi urad, ki zagotavlja vso logistiko za ameriške, evropske, japonske in kanadske člane posadk, ki se usposabljajo v Zvezdnem mestu in pripravljajo za odhod v vesolje. Interview is also in English

V mesecu avgustu sva se s planespotterskim kolegom Vladimirjem (oba sva člana SloPlanespotters team-a) po enoletnem premoru ponovno odpravila na tradicionalni, vsakoletni, tokrat 2-dnevni »trip« na letališče München, natančneje Flughafen München - Franz Josef Strauß MUC/ EDDM (v nadaljevanju MUC).

Letališče je 7. najbolj prometno letališče v Evropi, prek katerega je lani potovalo 38,7 milijona potnikov. Letališče MUC je t. i. drugi hub Lufthanse, Lufthanse Citylina in Air Dolomitov, ki so stalnica letališča, prek katerega lete opravlja še 86 letalskih družb v potniškem prometu ter 7 tovornih oz. cargo letalskih družb.

Pot naju je vodila po avtocesti čez Karavanke, Beljak, Salzburg vse do Münchna, kjer je letališče MUC še 28,5 km izven mesta. Teh 28,5 km se ob 7. uri zjutraj, ko si poln adrenalina pred letalsko »meko«, vleče neskončno dolgo. Po prihodu na 1. planespottersko pozicijo letališča ob stezi 26L so naju najprej pozdravile meglice, saj je bila sobota, kot večina letošnjega poletja, deževna. Da sva to deževno soboto začela v veselem vzdušju, je poskrbel South African Airways z 2-urno zamudo, saj po točnem času prileti v MUC nekaj po 6. uri zjutraj, a tokrat je njihov A340-641 v najino veselje zamujal. Do 13. ure sva tako ujela še kar nekaj lepih letal, in sicer Qatar Airways z B787-8, Etihad Airways z A340-641, Arkio z B757-300 in v spremstvu vojaškega oklepnika Turkish Airlines z A330-300 ter seveda Lufthansina A340-641 in A330-300, žal drugih tipov  Lufthansinih »heavyjev« v MUC ni. Ravno tako v MUC ne boste zasledili Lufthansinih Boeingov na nobeni od njihovih linij iz in v MUC. Za zanimivost naj povem, da Lufthansa med Münchnom in Frankfurt/Main-om samo ob sobotah leti 9-krat dnevno z Airbusom A321-231. Samo ob sobotah v MUC pristane nekaj čez 400 letal in jih približno toliko tudi odleti.

Po 13. uri sva se prestavila na 2. spottersko pozicijo na prag steze 26R, kjer sva »pospremila« Unitedovo floto Boeingov B767-424ER (tisti dan kar 4) in Deltinega B767-424ER. Na najino veliko veselje je ravno v tistem času iz steze 26R poletel tudi Airbus A320-214 v barvah Etihad / Airberlin. Po »odpremi« vseh zgoraj naštetih letal sva se odpravila na kosilo v terminal. Kot zanimivost naj povem, da sva ob razglednem hribu in muzeju našla parkirno mesto, na katerem plačaš 1,50 € za 4 ure. Od tam do terminala je 1,2 km peš poti, kar pa ni tako hudo. Za primer naj navedem, da ura v parkirni hiši ob terminalu stane 4,5 €.

Po kosilu sva se vrnila nazaj na 1. planespottersko pozicijo, kjer sva pospremila odhod Emiratesovega Airbusa A380-841 za Dubai, ki sedaj s tem tipom letala leti v MUC 2-krat dnevno. Najbolje se mi zdi, ko pilot po navedbi let. družbe in številke leta v odgovoru kontroli letenja doda »Super«, ki je oznaka za Airbus A380. V preostanku dneva sva poleg Lufthansinih letal ujela še Croatio Airlines z Dashom 8Q-400, Etihad Airways z Airbusom A330-300, KLM z Embraerjem E190 in B737-800, Cyprus Airways z A320-232, S7 z B737-800 v barvah letalskega združenja One Word, Air China z A330-200, Aegean Airlines z A320-232, Air France s celotno družino A320 in še bi jih lahko našteval, saj je MUC zelo prometno letališče. Moram pa omeniti še en čarterski let, in sicer Bulgarian Air Charter z MD-82, dobri stari mad-dog in njegov zvok motorjev.

Vladimirjem sva se najbolj razveselila Adriinega presenečenja ob 20.25 na letu JP108, saj je tisti večer v MUC priletela »Vesna« (Bombardier CRJ900NextGen S5-AAV). Počakala sva vse do njenega odhoda ob 21.05, saj je prav fascinantno gledati »rush hour« ob 21.00 na letališču MUC.

Prenočišče sva si uredila približno 5 km stran od planespotterske pozicije v hotelu Hallbergerhof, kjer sva bila prav presenečena nad ceno (26,00 € po osebi) in storitvijo, ki so jo nudili za takšno ceno. Jaz bom rekel: »Nemci pač znajo«.

Sončno nedeljsko jutro je bilo kot naročeno za planespotting na letališču MUC. Prvo presenečenje Etihad Airways z B777-200LR in Airbus A340-541, kar je pomenilo v dveh dneh 4 različni tipi letal za Etihad Airways. Air Berlin naju je ponovno presenetil z Airbusom A320-214 Fan Force One ter Air France z A320-211 v barvah letalskega združenja Sky Team. Od vsega pa sem bil najbolj vesel naše Adrie s tremi leti: Ljubljana, Lotz in Priština. Jutranji let iz Ljubljane s CRJ900 S5-AAK, ki je let nadaljeval v Lotz, ter popoldanski let z A319-132 S5-AAR iz Prištine. Kar se je na letališču MUC spremenilo, je to, da so turbopropelerska letala po zaključku obratovanja let. družbe Augsburg Airways in prodaji letal ATR72-500 Air Dolomitov skoraj popolnoma izginila Edini let. družbi, ki sta še ostali s turbopropelerskim letalom, sta Croatia Airlines in Eurolot z Dashi 8Q-400, kar me zelo žalosti, saj ves čas največkrat videvaš iste tipe letal.

V nedeljo popoldan se je eden najinih zdaj že tradicionalnih izletov na MUC zaključil in pot naju je po ustaljeni »trasi« München, Salzburg, Beljak, Karavanke z 823 fotografijami in 172 video posnetki vodila proti domu.

Besedilo in fotografije: Miha Žnidar

Največja letalska nesreča nad ozemljem Hrvaške.

10.  septembra 1976 sta na deset tisoč metrih višine nad Vrbovcem, ne daleč od Zagreba, ob 11 uri in 14 minut, trčili potniški letali British Airways in Inex-Adria Aviopromet. Letalo Hawker Siddeley Trident 3B British Airways je letalo na progi London/Heathrow – Istanbul, letalo Douglas DC-9-32 Inex-Adria Avioprometa pa je bilo na progi Split – Köln/Bonn.

Britansko letalo je zadelo krilo letala DC-9, ki je odpadlo. Prizor je bil apokaliptičen. Deli letala so bili bolj podobni ožgani plastiki, kot pa železu, prtljaga in trupla so bili  razmetani na površini deset kilometrov v širino in 62 v dolžino. Raztreseni so bili po koruznih poljih, gozdovih in dveh vaseh - Gaj, na katero območje so padla trupla in prtljaga z letala Trident in Dvorišta, kamor je padlo letalo DC-9.

Zaradi usodne napake kontrolorja poletov v Zagrebu, 28. letnega Gradimira Tasiča, in posadke obeh letal, je življenje nad Vrbovcem izgubilo 176 ljudi. Mladi kontrolor  zračnega prometa je bil edini na sodišču spoznan za krivega in obsojen na sedem let zapora. Kasneje so mu kazen prepolovili. Kazni pa ni prestal do konca, saj je bil zaradi množične peticije svojih kolegov predčasno izpuščen na svobodo. V času nesreče je bila zagrebška kontrolo poletov prezaposlena. Tasič je bil ta dan tretji po vrsti v izmeni, ki je delala po 12 ur.

Strokovnjaki so kasneje ugotovili, da bi se tragediji izognili le za tri stotinke sekunde.

Skrivnost poleta JP550

Britansko letalo Trident Three G-AWZT, na letu št. BE476, je vzletelo z londonskega letališča Heathrow ob osmi uri in 32 minut. Običajni polet proti Turčiji je potekal preko zahodne Evrope in območja nekdanje Jugoslavije. V hrvaški zračni prostor je letalo priletelo štiri minute po 10 uri in se javilo kontroli zračnega prometa. Po oddaji osnovnih podatkov o višini leta na 330 (približno 10.000 metrov), je Trident nadaljeval polet brez stika s kontrolo letenja, saj ta ni bil več potreben.

Nekoliko prej je z letališča Split poletelo jugoslovansko letalo DC-9-32 YU-AJR,  na letu št. JP550, in se povzpelo v smeri Kostajnice. Letalo je upravljal pilot Jože Krumpak.

Ob 10 uri, 14 minut in 38 sekund so kontrolorji zračnega prometa izgubili stik z obema letaloma. Zgodila se je strašna nesreča takrat dveh najsodobnejših letal. V letalu DC-9-32 je bilo 108 potnikov,  večina turistov iz Zahodne Nemčije. Letalo DC-9 je z zadnjimi petimi metri levega  krila udarilo direktno v kokpit britanskega letala Trident, v katerem je bilo 54 turških potnikov. Potem sta obe letali padli proti zemlji. Deli letal so ležali v krogu sedmih  kilometrov. Krivda za nesrečo se je mesece dokazovala in na koncu pripisala zagrebški kontroli letenja. Ta je dovolila, da ste se letali znašli na isti višini in trčili vodoravno.

Nesreča, ki je nastala pri hitrosti letal 900 kilometrov na uro najbolje opisuje dejstvo, da so deli letala ležali med Vrbovcem in Križevci. Domačini vasi Gaj in Dvorišta se še danes spominjajo tega groznega dneva. Po nesreči so v vas prišli policisti in vojaki, bilo je obsedeno stanje. Trupla, kovčki, deli letala, jedilni pribori, stvari iz letala – vse je ležalo razmetano po strehah hiš in okolici. Trupla potnikov so bila razkosana.

»Bilo je nekaj najstrašnejšega, kar sem videl v svojem življenju,« se spominja prostovoljni gasilec Franjo Fabijanec. »Petdeset vaščanov je bilo v pomoč reševalcem in so ves teden po nesreči zbirali umrle in njihove stvari. To ni mogel delati vsakdo. Dali so nam sendviče in žganje, da smo lahko lažje zbirali vsa ta trupla. Tukaj na travnik je padlo dekle, ki je v nesreči ostala cela. Mladi so potem na to mesto prinesli cvetje in sveče. Vzdušje je bilo grozno,« še pove Franjo.

Gašenje požara

»Takšnega zla nisem nikoli videl! Ravno na mojo zemljo je padlo več mrtvih, med njimi tudi kapetan in stevardesa. Kovček s knjigami je padel tik ob hiši. Skoraj cela vas je bila prekrita,« pravi Valent. V vasi Gaj so še leta kasneje govorili o tem groznem dogodku. Nekateri domačini so mesece po tragediji v strahu hodili na polja, da ne bi kje naleteli na ostanke človeških teles.

Sedem kilometrov naprej se je zrušil in zagorel jugoslovanski DC-9. Osem minut po padcu letala so na kraj zrušenja prišli lokalni gasilci in kasneje gasilci iz Zagreba. Šele po osmih urah so lokalizirali ogenj. Večina trupel potnikov in stvari je zgorelo, zato je bilo kasneje težko narediti njihovo identifikacijo.

Preiskavo na terenu je vodil prof. dr. Zdravko Bukljaš, predavatelj na Fakulteti prometnih znanosti v Zagrebu in specialist za prometno-tehnična strokovna znanja v takratnem sekretariatu za notranje zadeve. Spominja se: »Bilo je grozno. Najprej smo morali prešteti vse dele teles, da smo tako določili številčno stanje potnikov v letalih. Organiziral sem obsežno iskanje na terenu. Sama preiskava je trajala dva meseca. Z izvedenci smo ugotovili, da sta bili obe letali v zraku v vodoravnem položaju. To je bil zelo pomemben podatek glede na to, da je večina trdila, da je bil jugoslovanski  DC-9 v fazi vzpenjanja v času udarca. Kasneje smo rekonstruirali celotno situacijo. V hangarju zagrebškega letališča smo sestavili preostale dele letala Trident.«

Usodna napaka zagrebške kontrole zračnega prometa je bilo pomanjkanje komunikacije med kontrolorji. Preiskava je bila osredotočena na mladega, takrat 28-letnega kontrolorja Gradimirja Tasiča, ki je na dan nesreče delal tretji zaporedni dan po 12 ur na dan. Za neopremljeno zagrebško kontrolo letenja je bilo običajno. Zagrebški center je bil eden izmed najbolj obremenjenih centrov kontrole zračnega prometa v Evropi. S premalo ljudi so morali spremljati približno 760.000 letal na leto. Tasič je bil pomočnik kontrolorju Mladenu Hochbergju, ki je nadziral letala v zgornjem sektorju, na najvišjih nadmorskih višinah. Tasič je tako stopil v stik z britanskim letalom medtem, ko je bila Hochberger kratkotrajno odsoten.

Jugoslovansko letalo, ki je letelo v srednjem sektorju je nadzoroval Bojan Erjavec s pomočnikom Gradimirjem Pelinom. Ko je slovenski kapetan Jože Krumpak zaprosil za dovoljenje, da se povzpnejo na višji višino, je moral pridobiti odobritev Hochbergerja ali Tasiča. Tasič je bil zaseden v pogovoru z drugim letalom. Bojan Erjavec se je zato odločil in osebno pristopil k njemu, ga potrepljal po rami in mu na monitorju pokazal piko - jugoslovansko letalo. Z gesto je zahteval, da mu Tasič potrdi vzpenjanje letala v zgornji sektor. Tasič je napačno razumel in je nestrpno prikimal, kot je kasneje povedal v svojo obrambo. Ta trenutek je odločil o nadaljnji usodi 176 življenj, ki so letela nad Vrbovec.

Usodni nivo 350

Erjavec se je vrnil v svojo mizo in kapetanu Krumpaku odobril dvig na višino 350.  Vendar, da bi prišel na to višino, je moralo njegovo letalo prečkati višino 330, na kateri je letel britanski Trident, ki ga je upravljal kapetan Denis Tann Victor. V zadnjem trenutku je nekdo opazil, da pike na radarskem zaslonu preveč približujeta.  Kontrola letenja je začela panično komunikacijo s kapetanom Krumpakom in mu povedala, da ostane na višini na kateri se nahaja in da preneha z vpenjanjem. Toda bilo je prepozno.

Vseh pet kontrolorjev zračnega prometa je bilo v istem trenutku odstranjenih z dela in kmalu tudi pridržani. Sojeno jim je bilo v procesu desetletja, ki se je začel aprila 1977. Obsojen je bil samo Tasič na sedem let zapora. Kasneje so mu kazen prepolovili. Iz zapora je bil izpuščen predčasno zaradi množične peticije svojih kolegov. Danes je Tasič že pokojni. čŒeprav je bila v javnosti ustvarjena slika, da je Tasič odgovoren za nesrečo, je to daleč od resnice. Resnica je ta, da so bili zagrebški kontrolorji zračnega prometa v tistem času najbolj obremenjeni v Evropi. En človek je delal na treh delovnih mestih, trdijo mednarodne letalske organizacije.  Smrt tujih turistov je pokazala, kaj lahko povzroči varčevanje pri varnosti.

Po tridesetih letih so nesrečo upodobili na filmu.

Nesrečo je videl nemški pilot

Nesrečo, na višini deset kilometrov, je videl samo nemški pilot letala Lufthanse, ki je letel nekaj kilometrov stran. Opazil je ogromen blisk in nato gost dim. Svoje opaženje je takoj sporočil v zagrebški kontrolni center.  To je bilo nekaj minut po tem, ko je  kontrola letenja spoznala usodno napako.

Britansko letalo Trident Three je upravljal 44 letni kapetan Dennis Tann Victor, ki je  več kot dvajset let delal za letalsko družbo Biritish Airways. Letel je skupaj z 29-letnim kopilotom Brianom Edwardom Helm in prvim častnikom, 24-letnim Martinom Finta Honthana. Kabinsko osebje je imelo dve vodji stevardes in štiri stevardese.

Jugoslovansko letalo DC-9 je upravljal kapetan Jože Krumpak, 51-letni izkušen pilot  iz Rogaške Slatine, z več kot 10.000 urami letenja. Z njim je letel še 29-letni kopilot Dušan Ivanuš ter tri stevardese.

Prepis pogovora med pilotom britanskega letala Trident s kontrolnim stolpom v Zagrebu:

10: 4:12 Trident vstopi v hrvaški zračni prostor

BE476: Zagreb, Bealine 476, dober dan!

ZAGREB: Bealine 476, dober dan, nadaljujte

BE476: 476 Celovec na 02, 330 predvidevamo Zagreb 14

ZAGREB: Bealine 476 potrjujem (to je v redu), pokliči me, ko boste prešli Zagreb nivo letenja 330 (kontrolor letalu dodeli identifikacijsko kodo Alfa 2312)

BE476: 2312 prihaja, sem ga vključil.

(To je zadnja komunikacija britanske posadke z zagrebškim kontrolnim stolpom. Posadki se ni bilo več potrebno javljati, kar je običajno za načrtovane polete na običajnih koridorjih leta. Direktni udarec je odtrgal pilotsko kabino deset minut po zadnjem stiku z Zagrebom.)

Letalo Trident je imelo v času trčenja hitrost 889 km/h.

Pod številko JP550 je letalo vzletelo s splitskega letališča ob 09:48. 17 minut kasneje je posadka vzpostavila prvi stik s kontrolo letenja v Zagrebu. Prepis pogovora med pilotom jugoslovanskega letala DC-9 s kontrolnim stolpom v Zagrebu:

9: 54:49

JP550: Dober dan Zagreb, Adria 550.  Prečkamo 130 in se vzpenjamo na  180 v smeri Kostajnica.

ZAGREB: Razumem, odobreno 240, Adria 550.

09: 55:50

ZAGREB: Adria 550, odobreno 260. Sporočite prehod 220 (višina letenja)

09: 56:02

ZAGREB: Adria 550, Zagreb.

JP550: 550, 260 odobreno, pokličemo vas, ko bomo prečkali 240, me slišite?

09: 56:12

ZAGREB: Pokličite nas, ko se boste prečkali 220!

(Po številnih spremembah višine leta je kapetan Krumpak šest minut po 10 uri zaprosil za dvig na večjo višino od dosedanje 260.)

10: 05:57

JP550: Adria 550, letalo izravnano na nivoju letenja 260, čakamo na večjo višino.

ZAGREB: 550, žal 330… e… 310 ni prosta. Se morda lahko povzpnete na višino  350?

JP550: Da, da, z veseljem!

(Potem je prišlo do usodne napake v komunikaciji med Bojanom Erjavec in Gradimirjem Tasičem)

10: 07:40

ZAGREB: Adria 550, odobren nivo letenja 350

JP550: Hvala, vzpenjamo se na 350!

(Sledi vrsto pregledov tehničnih parametrov višine. Ob 10:14 kontrolorji na zaslonu radarja opazijo točki, ki se približujeta. V kontrolnem stolpu je nastala panika.)

10: 14:14

ZAGREB: Kakšna je vaša trenutna višina leta?

JP550: 327

ZAGREB: (jecljanje) ... e ... zadržite letalo na tej višini!

JP550: Na kateri višini?

ZAGREB: Na kateri ste sedaj v vzpenjanju! E... pred sabo imate letalo na is….(nerazumljivo), 335 od leve proti desni!

JP550: O.K., ostajamo točno na 330.

(To je bilo zadnje sporočilo jugoslovanskega letala DC-9 zagrebški kontroli letenja.)

Od višine leta 327 je minilo 12 sekund, dokler je posadka dojela, da mora ohraniti svojo sedanjo višino. V teh 12 sekund se je letalo povzpelo za 150 metrov in doseglo višino 32.850 čevljev. V naslednjih 9 sekundah, ko je posadka kontroli sporočila "O.K., ostajamo točno na 330." se je letalo povzpelo še za naslednjih 100 metrov in doseglo višino 32. 950 čevljev (330).

Zapisovalnik podatkov o letu (črna skrinjica) je zabeležil, da je bilo letalo pred trčenjem v vodoravnem letu s hitrostjo 861 km/h in na višini leta 330, 10.000 metrov.

Besedilo: Franci Jeraj

Vir: Revija Letalo