Gloster Javelin ...its short career
Originally Posted by Foxed Moth
And one day at Farnborough "Simon's Circus" flew Sea Vixens in such a way as to remain in my memory almost 40 years later... but for all that I don't know that any other air force looked at the Sea Vixen as a purchase.
Just for you, out of the archives: Farnborough 1968 programme
Join Date: Jan 2006
Location: Fife
Age: 87
Posts: 519
Likes: 0
Received 0 Likes
on
0 Posts
Centre-line Closure
[As for falling out of the sky in flames, I believe this was a 'centre-line' closure problem. I could be wrong but I believe that the combustion chamber was in two halves and at high temperatures it form a figure of 8 rather than an O. The turbine blades with then hit the walls and induce an engine failure and fire.]
Pontius.
The Sapphires installed in the Javelin developed a number of interesting technical failures throughout the aircraft’s career.
Turbine failures were an early example, the “solution” was to install a form of armour plating around the rear end of the engine, so as to catch the exploding bits of blades before they destroyed the airframe.
Engine fire warning light illumination was a fairly regular occurrence; this could signify either a fire or a hot gas leak. Most of the time, though, it signified a faulty detector unit; if the red light(s) were a nuisance, particularly at night, one “cure” was to take the bulb(s) out during the RTB.
Centre-line closure was the most significant engine problem we encountered and was, I think, recognised only after the Dragmaster started flying further afield, since some tropical weather conditions provoked the failure. The problem affected the compressor, not the burner or turbine assembly; it happened when the engine was operating at high power and was subjected to rapid cooling (climbing up the middle of a tropical Cb was a good way to achieve this). Uneven contraction rates within the compressor then led to the rotating bits meeting up with the static bits, with dramatic results. I had a close up view of this when in close formation with a Mark 9 which did just this. The pilot did not survive, but the navigator’s subsequent account confirmed that the disintegrating compressor had immediately severed the hydraulics so that the flight controls were inoperative (from the spectators' viewpoint, the aircraft pitched nose down so sharply that neither I nor the number 3 could follow it through the cloud); the electrics were destroyed to the extent that not even the generator warning lights worked. Without intercom, the first indication he had that the situation was irretrievable was when the pilot’s ejection seat fired.
Once centre-line closure had been recognised, the initial reaction was to ban Javelins from flying in cloud. A couple of T3s of the Instrument Rating Squadron needed to return to Middleton St George from Nicosia and were given dispensation from the ban for the return flight. On their climb out of Orange as a close pair they met up with an embedded Cb and lost 3 engines out of the 4; the “glider” pilot ejected successfully, the other managed to get back to Orange with very much reduced power available on the surviving engine. The technical solution to centre-line closure was the Rockide (sp?) mod. which amounted to coating bits of the compressor with heavy duty abrasive, so that the blades would file themselves down, rather than go to bits.
Later on, Victor crews became worried that their Sapphires, too, might suffer from the closure problem. I believe that manufacturers' experts reassured them that, because of the difference in intake design this could not happen. This expert opinion changed only after a Victor pilot flying from Tengah earned his AFC by coping with failure of 2 of his Sapphires; at one stage he had only 1 engine functioning.
I also heard that news of this Sapphire problem did not surprise the USAF, who had already encountered something similar years before on the B47.
Pontius.
The Sapphires installed in the Javelin developed a number of interesting technical failures throughout the aircraft’s career.
Turbine failures were an early example, the “solution” was to install a form of armour plating around the rear end of the engine, so as to catch the exploding bits of blades before they destroyed the airframe.
Engine fire warning light illumination was a fairly regular occurrence; this could signify either a fire or a hot gas leak. Most of the time, though, it signified a faulty detector unit; if the red light(s) were a nuisance, particularly at night, one “cure” was to take the bulb(s) out during the RTB.
Centre-line closure was the most significant engine problem we encountered and was, I think, recognised only after the Dragmaster started flying further afield, since some tropical weather conditions provoked the failure. The problem affected the compressor, not the burner or turbine assembly; it happened when the engine was operating at high power and was subjected to rapid cooling (climbing up the middle of a tropical Cb was a good way to achieve this). Uneven contraction rates within the compressor then led to the rotating bits meeting up with the static bits, with dramatic results. I had a close up view of this when in close formation with a Mark 9 which did just this. The pilot did not survive, but the navigator’s subsequent account confirmed that the disintegrating compressor had immediately severed the hydraulics so that the flight controls were inoperative (from the spectators' viewpoint, the aircraft pitched nose down so sharply that neither I nor the number 3 could follow it through the cloud); the electrics were destroyed to the extent that not even the generator warning lights worked. Without intercom, the first indication he had that the situation was irretrievable was when the pilot’s ejection seat fired.
Once centre-line closure had been recognised, the initial reaction was to ban Javelins from flying in cloud. A couple of T3s of the Instrument Rating Squadron needed to return to Middleton St George from Nicosia and were given dispensation from the ban for the return flight. On their climb out of Orange as a close pair they met up with an embedded Cb and lost 3 engines out of the 4; the “glider” pilot ejected successfully, the other managed to get back to Orange with very much reduced power available on the surviving engine. The technical solution to centre-line closure was the Rockide (sp?) mod. which amounted to coating bits of the compressor with heavy duty abrasive, so that the blades would file themselves down, rather than go to bits.
Later on, Victor crews became worried that their Sapphires, too, might suffer from the closure problem. I believe that manufacturers' experts reassured them that, because of the difference in intake design this could not happen. This expert opinion changed only after a Victor pilot flying from Tengah earned his AFC by coping with failure of 2 of his Sapphires; at one stage he had only 1 engine functioning.
I also heard that news of this Sapphire problem did not surprise the USAF, who had already encountered something similar years before on the B47.
Last edited by NutherA2; 24th Apr 2006 at 17:04.
