Human-Computer Interaction 3e Dix, Finlay, Abowd, Beale
This is the full story of the ill fated Draken and its drop tanks. The original of the spitfire controls in the second edition (p.47) was completely wrong (all Alan's fault!!). Happily Kai-Mikael Jää-Aro corrected us as described in /e3/online/spitfire/.
by Kai-Mikael Jää-Aro
The Englishman [sic!] Oscar Wilde said some pointed, intelligent and well-formulated things at the beginning of the century. One of his witticisms is goes approximately like this: "One's own successes are encouraging, but the failures of others are not to be despised." [I haven't been able to find the original form of this quote.]
Your successes you'll have to enjoy on your own. This article is written for you who has screwed up in the air. Who is embarrassed, feels like a complete fool and the unparalleled master of big mistakes. You are wrong, you are just an amateur. Read on and console yourself with what the real experts can cause.
The Mistake with a capital M happened one spring day at and outside the Wing [F11] in Nyköping. The star role was played by Sierra 44, an S35E Draken [reconnaisance version of the J35 Draken fighter], an aircraft that was doomed from the start and now rests on the bottom of the Baltic Sea outside Häradsskär.
The pilots of the Wing were to compete with each other for two days in noble games such as shooting, life boat paddling, orienteering and, not least, flying. Since the Wing flew both Lansen two-seaters and Draken one-seaters, the Drakens flew in pairs to make even teams for the ground-based exercises.
When the third Draken squadron had divided itself two by two, there was a lone lieutenant left on the floor. So that he would not have to fight alone he was assigned the first reserve, an SAS [the airline, that is] first officer, who had been in for a two week refresher course and therefore was considered capable of tagging along as wingman.
The happy SAS pilot, a kindly but somewhat talkative person, had a special trait. He could never, couldn't then, and probably never will, be in time. His many interests and mobile intellect are too much for the meagre allotment of time we have on earth.
The flying task, a nap-of-the-earth navigation and photographing exercise, was described in a sealed envelope that was given to the crew twenty minutes before takeoff. Due to the special character trait of the SAS pilot the short period of twenty minutes was spent more on theoretical discussions than practical preparations of the navigation.
Suddenly the leader realised it was three minutes left to takeoff! With a scream he grabbed the semi-prepared maps and rushed out through the closest door in the direction of the aircraft. His wingman followed with both feet and talking apparatus going at high speed.
They jumped into their aircraft, started the engines, taxied out, read the pre-start checklist and strapped in, in that order.
The Drakens rounded the corner of the runway on the dot, with high tails, screaming tyres and open throttles. With lit afterburners they set off along the runway.
The normally much calmer and controlled leader had by this time become somewhat flustered from stress and hurry. Probably it was this slight lack of well-being that caused him to make a small but fatal mistake. He took off from the runway at too low a speed.
The aircraft rose a few metres, retracted the wheels, whereafter Sierra 44 fell down on the runway again. With an audible "clunk" and a short squeak from the two drop tanks that got squashed the aircraft bounced up in the air again - and went on flying!
The "slightly scratched" drop tanks had lost their rear ends, so kerosene was streaming off the aircraft. By the jet exhaust it caught fire and turned Sierra 44 into a gigantic flying fireball that with rapidly increasing speed went like a warning omen over the Sármland sky.
The wingman - who suddenly and unexpectedly found himself inside the fireball - shouted on the radio in a desperate voice: "Sierra 44, you are on fire. Bale out!"
The fiery flyer for his part had already noticed that there was a fire, but not in the aircraft, but only in the kerosene around it. He decided to quickly get rid of kerosense and fire by dropping the tanks and attacked the little red button under the canopy border with his left thumb.
This is probably the place to describe some of the technical peculiarities of the reconnaissance Draken. All such planes have gone to a premature death and are scrapped with often more than half their useful service life left, so these disclosures can hardly be considered a breach of military secrecy.
All Swedish Drakens have, or have had, two attachment points for drop tanks, except the reconnaissance Draken, which was to go far and fast and therefore could take four tanks. The aerodynamics were such that if the pilot dropped all four tanks simultaneously, the aircraft twisted around with such speed that it met itself and collided.
Therefore there was a selector betwen fuselage tanks and wing tanks such that only two at a time could be dropped. That nothing happened when our pilot pressed his button was of course due to this selector being set to "WING TANKS" while the aircraft only had fuselage tanks mounted. Usually one cannot drop something one does not carry.
This technical peculiarity had for the moment been completely forgotten by our pilot, who instead suspected a "mispress", that he had gone for the wrong button. He looked down looking for red buttons and found a new one that he pressed.
If he hadn't been hot and bothered before, he was now. The new button was marked - in very small letters - "CANOPY EMERGENCY RELEASE".
The pilots in the Air Force were at that time trained for calm and controlled behaviour in the heat of battle. The total crisis that now was present therefore logically caused the pilot to regain his calm and harmony. In a split part of a second the situation was clear to him, the causes and the remedying actions.
He toggled the selector, dropped the leaking tanks and went around to land at Nyköping with his 35 "Convertible".
There the problems could have ended for the day. In fact they had hardly begun.
The dropped tanks had the larger part of eastern Sörmland as potential target, but yet chose to hit the Grängesberg-Oxelösund railway, a feat in itself as it has a narrower gauge than the usual SJ [Swedish State Railways] tracks. The voluntary fire brigade in Stigtomta turned out and in good spirits and with a lot of foam managed to extinguish the fire with commendable speed.
The good spirits rapidly departed when they realised the mistake. The gravel ridge under their and the railway's feet contained, apart from approximately 500 litres of kerosene moving downwards, also the water supply for the city of Nyköping. If kerosene and water were to unite, the future of the ridge as a water supply was finished for the next 50-100 years. What to do?
The same, but in reverse! Brooms and shovels out and foam away. Then set fire to the railway and the kerosene again. After four hours the kerosene had burnt out and the ridge was saved!
The lost canopy should also be retrieved before the horrid enemy and other industrial spies found it. The Wing engineer rapidly borrowd a pilot with a little helicopter from the Artillery Flying School on the other side of Nyköping and together they swept away with their eyes to the ground.
The search was fairly unnecessary. The canopy had landed fifty metres from a little playing boy who was neither impressed nor scared. He went in to his mother and said: "There's an aeroplane in our yard."
The somewhat excited mother immediately called F11 and said: "My son Hudor says there is an aeroplane in our yard."
After a short description of the object it was clear to the Wing that the canopy had been located. The engineer however could not be stopped. He had landed with the helicopter in order to study a suspicious-looking object and did not respond to radio calls.
While the engineer was searching in the busehes the helicopter pilot rose into the air again to continue searching on his own.
In hindsight on can say that he should have been looking at something else than his own, since he never noticed a badly placed power cable. The rotor got caught in the cable, the helicopter fell to the ground with a crunch and was turned into scrap.
When the dust had settled, the pilot opened his eyes, looked through the windscreen and removed it from his face where it had ended up. Then he stood up in the middle of the scrap pile.
Of the originally three rotor blades on the helicopter remained only one half. It was still attached to its axle, which rotated at a low but noticeable speed. The end of the blade hit the pilot right in the head, scalped him and sent him on to three months in hospital.
If you still think you have made a big mistake, forget it. You are, as you see, just an amateur and should look out when the experts get at it again.
What happened to Sierra 44? Well, the machine was doomed from the beginning. That it survived the fatal flying contest didn't mean Fate was going to let go of its prey.
A grey day in February that aircraft returned after a flight with a pilot that reported an abnormally large oil consumption - however he knew that, as there was no instrument in the cockpit showing the amount of oil.
The Wing engineer and his deputy had gone far away in the line of duty.
Number three, that now had to act, didn't have a very large experience of things like this, but his ability for decisive action was great.
"The pilot says the oil will run out in 10 minutes, but I don't believe that", he said. "He can't know that! Send the aircraft for a test flight. Nyköping to Gotland and back, minimum altitude, maximum speed!"
The number three Wing engineer was quite right, the oil lasted longer than 10 minutes. It lasted for 12. By that time the aircraft was on its way home somewhere far outside Arkásund. The engine said "CLUNGK" and stopped dead. The pilot tried to glide back to the coast of Östergötland with bad results. At 500 metres and clearly headed downwards he left Sierra 44 to its destiny and the plane went through the ice to its cold grave, where it rests to this day.
The pilot looked at the spectacle hanging from his parachute when he discovered that just below him was a hole in the ice covered by only a thin glistening sheet of ice!
He stretched his legs to go cleanly through the ice and that caused the second "CLUNGK" of the day!
The ice was half a metre thick - the thin crust was just an illusion!
The stiff legs collapsed completely from the shock against the ice and couldn't be used for normal walking and standing for the nearest half an hour.
Due to this the pilot looked fairly deceased where he lay on the ice with his parachute beside him, which was far from the truth, as he was completely unharmed, apart from the "leg shock".
Thus was caused the most dangerous situation of the entire day. The rumour of the fate of Sierra 44 spread over all of Götaland and half of Svealand with surrounding coastal areas. Soon the airspace over the crash site was full of Drakens, Viggens and other smaller flying objects circling at minimum height, with all eyes looking at the hole in the ice, and none at the others in the air.
That no-one hit anyone else in that mess was the great miracle of the day.