High altitude flying
with F-104

By Jan Meyer

With the supersonic interceptor, F-104G Starfighter, the Norwegian Airforce litterally jumped a generation of fighters. The planes destined for 331 squadron, arrived in Bodø harbour from the USA on a support-carrier in 1963. Unloaded by crane, the fighters were towed through the streets of the town to enter the airbase. Years later, two-seaters and a simulator arrived. Only the most experienced pilots underwent transition to the F-104 in the beginning, and this contributed to an outstanding safetyrecord, even if the area of operation would be the among the most demanding on the planet. The Starfighter was often referred to as the missile with a man in it, and its performance was tremendous.

Jan Meyer intervjues the former head of 331 squadron, later Airforce general and secretary general in the Norsk Aero Klubb; Olav Aamoth.

One late night in august finds Flynytt´s corespondent sitting in a window seat on SK 1345 to Trondheim watching the terminal building at Oslo Airport from the end of runway 01L, while the crew wait for takeoff clearance. The building looks like a modern rendition of a fairy tale castle with all itÕs different coloured lights at all itÕs levels. How should such a motif be photgraphed so the fairy tale look would show? The thoughts are interupted by the arrival of the clearance, the Boeing starting the takeoff roll. The lights along the runway edge move rearwards with increasing speed. Pilot Flying knows his craft, the rortation is almost imperceptible and we can once again experience the magic moment when the wings takes over the weight of the airplane and the runway edge and the lights fall away. The thoughts seek back to the day that just has passed...

- It takes one to recognise one, Olav Aamoth answers our sugestion that he must be one of the most eager aircraft enthusiasts we have ever met. WeÕre sitting in the library in NAKÕs headquarters in Tollbugaten in Oslo and talk about the time when he was CO of 331-squadron in Bod¿ at the end of the sixties. The table is full of notes, graphs and pictures. Both of us are coffee lovers, a thermo bottle and two mugs are also on the table. We have arranged this meeting to learn about a particular part of the work that was done at the squadron.

- When the F-104 arrived in 1963, Aamoth begins, - it was 331 squadron that got the honour of operating it. In many ways it was a revolution in technology and perfomance. We went from navigation with watch, compass and map in a plane that could barely reach mach 1.1 in a vertical dive from 40.000 feet to a weapon that was equipped with inertia navigation, map reading radar with terrain aviodance function and which could reach mach 2.0 in a climb. High takeoff speed (it takes to the air between 190 and 210 K) and landing speed (long, flat final between 170 and 185 K). Turning radius nobody had even dreamt of also belonged in the picture. (Glidespeed without engine was 285 K and High Key for a deadstick landing was 20.000 feet). The fighter gave us a range of possibilities as well as a range of challenges for those who flew it and those who maintained it. At first it was put in the fighterbomber role, the extreme speed and altitude perfomance were not interesting. The Canadian Forces further south in Europe utilized it the in strike role and if we may put it that way, with great success. This kind of utilisation wasnÕt even of academic interrest for our headquarter. In 1965 it was apparent that the F-86 K was completely insufficent as interceptor against the threats we were facing. We could neither reach nor follow the substancial Sovjet trafic with BADGER bombers down to our waters. And we were in no circumstance able to reach any of what was operating further north. We had no need for war, be it cold or warm to maintain daily tension. The Northern Norwegian winter weather supplied plentyful of that.

He makes a short pause, leafs through some of the papers before continuing; - It became apparent that F-104 would serve us better in the air defence role, particularly since our old F-86s were replaced with F-5s. 1. April 1967 I was appointed CO for 331 squadron and part of my assignment was retraining it to an all weather air defence squadron (AWX). 1. November we had completed the transfer program and were declared operational. The transfer program included training in using our most important "weapon", the Leica. This small, light and extremely good camera was standard equipment on board, but it posed a bit of a challenge to teach pilots not particularly interrested in photography to use it. Remember, it was completely manual. You had to adjust shutter, f-stop and focus and snap pictures of the target, preferably several exposures with varying combinations of shutter and f-stop and simultaneously fly the fighter. No one attained operational status before they had turned in an approved film.

We interrupt: - From our own experience we remember intelligence briefs that drew up pictures of intense military activity all way up to the border east of Kirkenes on the Sovjet side, particularly if there were excersises in progres on our side. Could you expand on apparent threats?

- You may safely say that we experienced the Sovjet superpower´s ambitions to dominate the high seas as a threat. The fleet in the north was expanded and presence on all seas increased. At our lattitudes we percieved it as an increase of trafic in transit to other areas and as increased excersise activity by Sovjet´s most modern aircraft types in our own close quarters. A scenario with attacks against the most northerly parts of our country to secure advanced bases and to improve defence of the Kola bases was an absolute possibility. Our practical area of interest was the coverage area of our radar warning system. - What Sovjet aircraft were involved? - Even before the squadron was declared operational we were getting results. Training missions occationally stumbled across "Zombies" that flew through our training areas. The first good pictures from our Leicas were duly celebrated the summer of ´67. During the next two years we encountered most of what the Northern Fleet, DA, Border Patrol or KGB operated. Most were of course comparatively simple targets, BAGDER, BEAR and BISON in all varieties.

Some were slow like CUB on the "milk run", others were high and fast as BLINDER. The most difficult were the ones that went low in ground clutter and the slow ones at high altitudes. A BADGER at mach 0.6 at 40.000 feet made life troublesome for a 104-driver, particularly at night. I see that you´re doubting, shouldn´t a 104 manage a slow BADGER?



Remember that the fighter had high stallspeed. At mach 0.6 at that altitude it would barely be above stallspeed and well behind the power curve. Aamoth continues: - We knew there were things that flew above BACKFIRE, not only U2 ans SR 71. Intelligence reports had for a long time described a Sovjet "U2" and we were well aquainted with MANDRAKE and FOXBAT. We wanted to encounter and photograph or engage such targets. By the way, BACKFIRE wasnÕt seen until long after the zoom program was completed, but there were rumours.

- We seem to remember some basic facts that up to 30.000 feet altitude man can manage by gradually substituting nitrogen with oxygen to maintain partial pressure. Over 30.000 feet you have to resort to pressure breathing to get sufficient oxygen. If we climb above 48.000 feet we will need a pressure suit, we recall from an old indoctrination.

- Absolutely correct, Aamoth replies, - Of course our fighters have pressurised cockpits, but pressurised cockpits may fail or be shot apart. Anyways, pressurisation is lost if the engine stops. In peacetime we normally limit maximum altitude to 50.000 feet. He searches through the papers and produce a transparency with a graph. - Take a look at the fighter´s flight envelope, he says, - the K could only cover the lower part of it, up to mach 1.0 and up to approximately 45.000 feet, slightly smaller than the 104 in military power, that is without the lighting afterburner (AB). You see that the 104 is largely limited to 50.000 feet and mach 2.0.

But if we swap speed for altitude we can reach higher. We know that light C-models have been zoomed to more than 100.000 feet. You may see from the graph that that such a high zoom is not very interesting for interceptions, there is no margin for maneuvering, we have to stay below the 1.0 G stall line to be able to maintain altitude and have a small margin for manuevering. So we set out to determine how high we could reach and still fly past the taget with control in order to identify and photograph it.

- You actually wanted to develop tactics to utilise the 104´s zoom properties in order to intercept high flying Sovjet targets. Hadn´t the Americans already developed methods for this? - Lockheed had considered the problem to some degree, but we couldn´t use their results directly. We knew that the Dutch had done extensive research and posessed some knowledge. The first we had to tackle was physiological safety for pilots that were to fly that high. When the planes were delivered, some MC3 pressure suits came with them. They had been duly stored at Kjeller. They had been in storage too long, some rubber parts had to be exchanged, they were uneconomical to repair.

We bought three new ones. Dr. Vogt Lorentzen at FMI had studied problems pertaining to flight above 48.000 feet and entusiastically wanted to participate in the project. He had good contacts at the American hospital in Wiesbaden. They supported the American operations with U2 and SR71 in these parts of the world. We were cleared by headquarters and together with capt. Langsrud from LFK we went to Wiesbaden in the fall of ´67. The Americans provided transport in an unbelievably cold C47. The Americans were willing to help us with our new MC3 pressure suits. They had the necessary support- and test equipment and access to a pressure chamber so we might test our equipment and train. Well home again we could proceed with the work. We adapted extra equipment to the plane´s survival equipmnet. We also got in touch with RNeAF´s department at Leeuwarden. They had done some work in the same field, had pilots in USA on Edwards as well as flown with Test Pilots School. They had put in a lot of work, on the parctical as well as the theoretical side and had decided to go for some French equipment which in their oppinion was better than the American.

- When did you start flying and who participated? - We were ready for the next step in the fall of Õ68. We, that is Johnsen, Westskogen and myself from the pilots and Ssjt. Thomassen from the Survival Equipment Section in Bodø went on our way to Wiesbaden in one of LKN´s Twin Otters. We had our three pressure suits in the lugage. We had the suits fitted and tested them in the pressure chamber. We made climbs to 80.000 feet and explosive decompressions to 60.000 feet. The latter was mildly spoken a different experience, but the equipment functioned as advertised. On our way home we went through Leeuwarden to discuss experiences and establish a flight program. The airport was actually closed due to construction, but our Twin Otter impressed by landing on the gras in front of the tower.

- We can see from the flight envelope that the problems you could encounter would be how the plane behaved at low indicated airspeeds. It looks like you will be short of load factor for maneuvering, we interupt.

- That is absolutely correctly observed, Aamoth answers, - During a zoom manuever the indicated airspeed could vary between 700K + down to zero in extreme cases. If the 104 got below 200 K it required particular attention. Aerodymaic maneuverabilty is lacking and if the plane is not on a stable path towards lower altitudes and higher indicated airspeeds, the plane and pilot would be in serious trouble. Precise control with angle of attack and nice nurturing of the engine was paramount. We wanted to find out how high we could go and obtain operational results. The practical side of it was finding out how high we could maintain level flight for long enough to pass a target, identify and photograph it and then return to base. Aamoth finds some pictures that were made at Survival Equipment Section in Bodø. They show a very young Westskogen being helped by Thomassen to don his pressure suit. The attire, if we may use such a word, looks like it belongs in a Flash Gordon cartoon. Finally he puts on his Air Force blue flight suit over the pressure suit. The picture of the flyer in front of his aeroplane clearly tells that it hardly was comfortable attire. It looks cramped and with limited room for movement, which Aamoth aknowledges. - The helmet was attached to a rail around the neck and didn´t have much room for movement. If you turned your head you would only see the inside of the helmet. It was poorly suited for what we intended to do, fly formation, observe and photograph to the side of the aircraft, he adds.

- How was the test program put together? - First we had to test the aircraft. Then we would develop tactics we could use, and then we wanted to establish a training program for the rest of the squadron. All in all we flew 25 trips during the summer ´69, all together 16 hours. The trips were shared between us three. Aamoth leafes through his notes again and produces a map. - In order to obtain reasonably realistic and repeatable conditions throughout the test program, he continues, - we esatblished a profile with a simulated intruder passing south west on the outside of VesterŒlen and Lofoten. You see the stippled line on the map. We scrambled the fighter which for the occation flew without external fuel tanks, only a pair of AIM9s (Sidewinders) on the Catamaran Launcher below the fuselage. The fighter should first get up, then accelerate to mach 2.0 behind the target so that it might zoom up and complete the intercept. If you look at the flight envelope you will see that steady state maximum thrust envelope tops just below nach 1.0. Then it decreases before it starts to rise againat mach 1.2 and wonÕt reach the mach 1.0 level before mach 1.3. In words this means that drag increases faster than thrust from the engine in this speed segment, and that it is necessary to trade altitude for speed to be able to accelerate further up to mach 2.0. We managed that by climbing in afterburner with mach 0.9 to 36.000 feet and then dive down again towards 20.000 feet to accellerate to mach 1.4. Then we had the power to accellerate to mach 2.0 and climb to 40.000 feet behind the target.

- How did radar guidance from GCI fit into this picture? We assume it would be GCI that were to scramble the fighter and would know where the target was?

- You can see from the map that the fighter weren´t sent directly to the target. It needed time and room for climb and accelleration. You may view the map with respect to the graph in "Standard zoom pofile". The tactic we developed was letting the interceptor climb on opposite course and with a 50 NM offset to the intruder up to 36.000 feet. We defined a gate (t=0) when we had a predetermined angle to the intruder and commenced the dive for accelleration. At gate plus 1:05 minutes at Mach 0.96 we commenced a turn into the intruder, altering course 110 degrees. At gate plus 2:20 minutes the speed had reached mach 1.1 and we rolled out on course. At gate plus 3:45 minutes we reached mach 1.4 and could commence climb again simultaneously with further accelleration. At gate plus 5:25 minutes we reched mach 1.7 and commenced turn to pick up the intruderÕs track. The alteration in course now was 70 degrees. At gate plus 6:35 at mach 1.8 we were paralell with the intruder. So at 7:05 minutes after gate we reached mach 2.0 and 40.000 feet behind the intruder and might commence the zoom, pull up point (PUP) if we had radar contact. We flew the zoom by pulling 2.3 G and lift the nose to 20 degrees above the horizon. Radar contact and very accurate flying were paramount. After pull up the aircraft was in a ballistic trajectory for all practical purposes and without much opportunity for correction of the flight path. How far behind the intruder we established and started pull up, roll out distance (ROD), depended on the intruders airspeed. It varied from 4.5 to 10 NM for target speeds between mach 1.4 and mach 0.9. How long time we would have paralelling the intruder depended on how high he flew. We tested intercepts up to 70.000 feet indicated, that is 74.000 feet true altitude.

- We mentioned GCI, there must have been som breaking of new ground at Reitan as well?

- Absolutely, tactics were developed in cooperation with the controllers at Reitan. They had to develop new tools as well. Radar operators use an aid they call handy dandy. Its a transparent sheet they place over the radar screen. The sheet has lines that aid the controller with calculating the headings to be flown in the different segments to effect an intercept. The traditional technique assumed constant speed. The aid lines are then straight. Since the 104 accellerated the entire time, the lines become curved. We had to make entirely new handy dandies and train people in using them.

- Did the rest of the squaron use the same program for training? You had as we understand, no more than three pressure suits and they seemed to be individually adjusted? Aamoth shakes his head,

- You touch the conclusion we reached. Fighter pilots in Northern Norway then as now operate largely over water during training and intercepts of Sovjet trafic. To give them a remote chance of survival in case of an ejection and where it is largely probable that he will land in water, he needs a good immersion suit. This requirement could not be combined with the pressure suit, there excisted no good combination. A typical intercept meant flying over ice cold sea more than half an hour and an intercept of a high flying intruder only meant no more than a minute and a half flying above 48.000 feet. Further, the pressure suit was cumbersome to don and unacceptably uncomfortable to wear over prolonged periods on readiness. We concluded that we could train to 60.000 feet without particular aids provided time over 48.000 feet didn´t exceed 90 seconds. The aircraft and it´s systems had demonstrated reliabilty that permitted this. Actual intercepts needed special authorisation anyway.

The old general smiles in afterthought and adds: - I have a special place in my memory for that aircraft. This work was clearly the apex of my work in my time as 104-driver. One felt like one mastered the heavens. The fighter had fenomenal power, it was a real hot rod and the engine got more powerful as the speed increased. At mach 1.5 the compressor changed mode, the turbine RPM increased with 4 % and accelleration increased further. What limited the engine and with that practical speed was compressor inlet temperature (CIT). That shouldn´t exceed 120 degrees. There was a reasonably large warning light in the cockpit that lit up in yellow if it got too hot there. We also had to watch the fuel diligently. We flew without external fuel and burned 450 pounds per minute during accelleration. The warning light for low fuel would usually come on during the turn away from the target. At that altitude there was little difference between full and idle thrust. We usually had 1100 punds remaining when we landed in Bodø. The margins were small. Aamoth collects his papers,

- No Norwegian fighters have been higher. And, he adds, - it doesn´t look like they will get there again for some time.




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