Buccaneer XV345
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Buccaneer XV345
Today is 41 years sine we lost XV345 over the Nellis range with the loss of Ken Tait and Rusty Ruston RIP Guys never forgotten I am no high flier in fact I was an SAC at the time but never forgotten from the ground side we were all a team. Dave
One of the most traumatic days of my career, as a young newly promoted Cpl and the only 2nd line Seat Bay man I was taken out to the site with the first responders. A truly tragic day for the squadron.
A work colleague of mine from the Airworthiness Dept at Brough took part in the subsequent investigation. He gave me a guide vane from one of the engines as a memento of the event. I kept it in my desk for about 30 years and I used to use it to remind people that no matter how good a job you think you have done, it might still not be good enough. At Brough we believed that the Buccaneer was one of the strongest and toughest airframes ever built. Sadly the Nellis accident and a number of other structural failures showed it could have been better, but hindsight is a wonderful thing and when you are pushing forwards the frontiers of aviation you occasionally get tripped up. It was a very sad and sobering time at Brough, especially after the very successful participation of the Buccaneer in Red Flag in 1977.
The subsequent investigation and findings on XV345 lead to a vastly improved understanding of fatigue management and formed a cornerstone of the MAA Structures Lectures for many years. The recovery program was thorough and lasted a few years.
But investigations are sometimes more fortuitous than scientific. My colleagues in the fatigue group couldn't understand why the wear on the Fin attachment lugs was so high. Until one of the management team visiting Lossie just happened (in the bar) to heard about the poor windscreen cleaning for salt at low level and how the crew pushed the button for fluid and kicked the rudder a few times to spread it - Bingo !
But investigations are sometimes more fortuitous than scientific. My colleagues in the fatigue group couldn't understand why the wear on the Fin attachment lugs was so high. Until one of the management team visiting Lossie just happened (in the bar) to heard about the poor windscreen cleaning for salt at low level and how the crew pushed the button for fluid and kicked the rudder a few times to spread it - Bingo !
Last edited by teeonefixer; 8th Feb 2021 at 22:29.
Yes, the low level Sea Eagle operations over the sea meant that the shortcomings of the windscreen wash system were highlighted. The fluid disappeared in the airflow before the single wiper could benefit. The aircrew had discovered that operating it with a bootful of rudder spread it better allowing the wiper to do its proper job. The unknown consequence was the high fatigue loading on the fin attachment fittings.
We still had one jet in service with the OLM system fitted but since the wash wipe operation wasn't signalled on the system - why would it be - that hadn't given us any early indication. There was however a lot of assessment of whether we could use the OLM data in the subsequent investigation. We did do some work looking at potential options, with a choice between strengthening the fin fittings or fitting a new wash wipe system (which was a novel business case) as well as advising the aircrew not to use excessive rudder when cleaning the screen but the problem eventually went away with the jets retirement.
We still had one jet in service with the OLM system fitted but since the wash wipe operation wasn't signalled on the system - why would it be - that hadn't given us any early indication. There was however a lot of assessment of whether we could use the OLM data in the subsequent investigation. We did do some work looking at potential options, with a choice between strengthening the fin fittings or fitting a new wash wipe system (which was a novel business case) as well as advising the aircrew not to use excessive rudder when cleaning the screen but the problem eventually went away with the jets retirement.
If I recall correctly, it was the RAFG jets without probes which suffered worst from the the windscreen washer problem as the UK-based aircraft's AAR probes caused sufficient airflow disturbance not to need the rudder doublet trick?
But by the time the probes went on and they flew to the Flag, the damage had already been done?
But by the time the probes went on and they flew to the Flag, the damage had already been done?
The Buccaneer windscreen wiper system file was about 2 inches thick and often used to reside on my desk. If you could read through it now, you would be able to see a distinct cyclic pattern with a wavelength of about 3 years. The crews in RAFG would complain about the difficulty of cleaning flies from the windscreen in the summer when flying low over the German plains. This was fed back to MoD in the UK who approached HSA for advice. On the first cycle we did a feasibility study and concluded the wiper motor was not powerful enough to drive the wiper above 450 knots and talked to Dunlop (I think) about uprating it. This was likely to be expensive and difficult and this was fed back to MoD. MoD then spoke to RAFG and got a response that there was no problem, either because it was now midwinter, or the original complainant had been posted. HSA were advised no action would be taken. The next summer, the cycle starts all over again.with new people in the MoD and RAFG part of the loop..........
I don't think snaking the aircraft with the rudder to spread the washer fluid was implicated in the XV345 accident. Although I am not a structural expert, I seem to remember rolling pull ups and the extended wing tips played a bigger part of the increased fatigue damage seen by the RAF fleet.
The timescale for modifications progressing from requirement to solution could be embarrassingly long and both MoD and HSA had to share responsibility. I remember being surprised to discover someone in Electrical Labs was still working on a system to automatically synchronise aileron droop and tailplane flap 6 months after the aircraft was retired from RAF service.
I don't think snaking the aircraft with the rudder to spread the washer fluid was implicated in the XV345 accident. Although I am not a structural expert, I seem to remember rolling pull ups and the extended wing tips played a bigger part of the increased fatigue damage seen by the RAF fleet.
The timescale for modifications progressing from requirement to solution could be embarrassingly long and both MoD and HSA had to share responsibility. I remember being surprised to discover someone in Electrical Labs was still working on a system to automatically synchronise aileron droop and tailplane flap 6 months after the aircraft was retired from RAF service.
As I recall, the accident to XV345 was due to a fatigue failure in one wing stub spar due to surface cracking and it was not related to any fin failure. I had finished the OCU a few days before and then did not fly the Bucc again until September 1980. We were all very shocked, especially following the loss of an aircraft in Germany the previous year when the wing fold latch pin failed in fatigue. Luckily the crew ejected from that one.
The problem with the screen wash was that, with the AAR probe fitted, it flowed from bottom right of the windscreen towards the left side and so did not clear away all of the salt etc, hence the rudder cycling. The windscreen wipers had a limit of 350 KIAS/0.6M (again, from memory) so could not be used at normal tactical low level speeds. A couple of times I did have the screen wash stick on and it took about 10 minutes for the fluid to run out so that you could see where you were going!
The problem with the screen wash was that, with the AAR probe fitted, it flowed from bottom right of the windscreen towards the left side and so did not clear away all of the salt etc, hence the rudder cycling. The windscreen wipers had a limit of 350 KIAS/0.6M (again, from memory) so could not be used at normal tactical low level speeds. A couple of times I did have the screen wash stick on and it took about 10 minutes for the fluid to run out so that you could see where you were going!
Lomcevak - I took a number of windscreen wash valves apart under F760 investigations raised because of the problem you and many others encountered. It was an odd concept, effectively a pneumatic timer relying on a stored volume of air escaping from a reservoir through a restrictor to close off the valve after 10 seconds. Unfortunately, for reasons best known to himself many years previously, the valve designer in the Brough drawing office had chosen to size the O ring groove dimensions to tolerances which were different from those recommended by the O ring manufacturer. Nothing was ever done to improve the design, Nowadays I doubt any aircraft manufacturer would consider using a pneumatic timer valve when a microchip and solenoid valve could do the job, but that's progress for you.
