Ramblings from the AEO’s Panel – Part 8

Ramblings from the AEO’s Panel – Part 8

Barry Masefield was the Air Electronics Officer (AEO) for Vulcan XH558 and had flown in this iconic aircraft for over 30 years, also being a key member of the Vulcan Display Flight (VDF), the RAF Unit which memorably flew the aircraft on the Airshow circuit until September 1992. Barry was also a member of the crew that flew XH558 into Bruntingthorpe Airfield on 23 March 1993 – her final flight in RAF service.

Since 558 flew at the Sunderland seaside show she has gone through a fairly torrid time. Who would have guessed that after those very successful couple of displays flown at Sunderland by Kev Rumens, Bill Ramsey and Phil Davies, events would unfold to ground our aircraft.  As most of you will be aware, a few days before we were due to fly at the Bournemouth, Shoreham, Oxford and Dawlish displays, Taff and his team were fuelling the aircraft up to the appropriate capacity when they noticed a fuel leak dripping from an area just aft of the nose-wheel doors.  Refuelling was immediately stopped for investigations to be carried out.  You may not be aware of the aircraft fuel system, but we have a total of fourteen fuel tanks, ten of which are in the wings.  As part of the fourteen tanks, we have four very large tanks (the biggest on the aircraft) which are in the main fuselage and positioned just above and aft of the nose wheel area. Unfortunately, the leak was in one of those very large tanks, No2 to be exact. 

I have been asked the question by some of our supporters that if there was a leak in a tank then why didn’t we fuel up all the other tanks and leave that one empty and continue with the planned display weekend.  For a host of reasons we couldn’t do that.  Firstly there was a safety issue, we have always prided ourselves on the fact that when we display in front of the public we do so with a fully serviceable aircraft that represents no danger to the assembled audience.  If we start to relax that ethic it can be the start of a very slippery slope and one that the VTTS is not prepared to be engaged in.  Secondly, there was an aircraft electrical system operating consideration. The following starts to get a bit technical so apologies to those of you who may get bored by what I’m about to describe.

We have two 28volt DC electrical operating systems that control all the relays which allow the operation of their associated equipments.  They are called the Essential and the Non Essential DC electrical systems. The Essential system ensures that the aircraft can always maintain an electrically safe flying configuration should any 28 volt DC electrical problems occur. The Non Essential system works in concert with the Essential system but its primary function is to ensure that the aircraft can complete its primary role as a bomber (not a role we envisage doing any time soon!!). If we have an electrical problem with the aircraft then the AEO has the ability to isolate the 2 systems by switching off the Non Essential DC electrical system. Sorry if I’m boring you but not much longer to go!!  Our fuel tanks are controlled by both the Essential and the Non Essential 28 volt DC systems, those in the wings are controlled by the Non Essential system and the big fuselage tanks above the nose wheel bay being controlled by the Essential system. Still with me people?  Now let’s suppose that while we are flying on our way to Bournemouth we have a 28 volt DC electrical malfunction which necessitated me having to switch off the Non Essential system. That will switch off all the wing fuel tanks leaving us with only the fuselage tanks to fuel the engines from.  Oh dear, didn’t we say that we wouldn’t put fuel in the No2 fuselage tank because it had a leak and now our DC electrical system will only allow us to use the fuselage tanks. Oops. The situation is not only embarrassing because now we haven’t got any fuel in the No2 tank to run the engines, but downright dangerous because we need as much fuel as it takes to either get home or to land at an emergency airfield. So you can see that what seemed such an easy solution to the problem of a leaking tank by not putting fuel into it has turned into a potential nightmare. That’s it people, electrical lecture over. Phew!!

Having discovered the leak there was no other option but for our engineers to drain the tank and inspect it to discover the source of the leak. Draining it is easy; the next bit is a bit more complex.  As you can imagine, a tank that has recently been drained of its fuel is still full of very highly toxic and explosive vapour, so the tank has to be filled with compressed air to blow the vapour out. I’m not too sure of the safety distance around the aircraft when this procedure is being carried out but I’m sure that there was no-one having a crafty cigarette within a hundred yards. Anyway, once the tank had been safely evacuated of all its fumes our techies could get inside it to inspect for leaks. They did indeed discover a few pin prick holes and so the decision was made to take the tank out and send it off to the factory in Portsmouth for repair. Unfortunately, so I’m told, the factory personnel were all stood down on their summer holidays and wouldn’t be back for a couple of weeks. It was obvious that we were not going to be able to fly the Bournemouth display weekend but we really would like to fly the following weekend at Dunsfold if it was at all possible but it looked as if that was going to a pipe dream.  However, our guardian angel came to the rescue yet again. The factory found some of their workers who were prepared to work on the tank even though it was their holiday time and within a couple of days had got the thing repaired. To say ‘thank you’ to these guys is just simply inadequate, they ensured that potentially thousands of the public would get to see us again very soon and it was all due to the efforts of those guys at the factory down in Portsmouth.

The tank was duly delivered back to Taff and the lads who then set about refitting it. Once it was in it had to be pressure tested to ensure that there were no further problems and then they could fuel it up ready for our flight to Dunsfold the following weekend. The phone calls went out from Martin Withers to me and Bill Perrins; we were going to be the crew alongside Martin for that flight. Having already planned the trip and drawn up maps and charts in anticipation that Taff and the engineers would have successfully weaved their magic and got the aircraft serviceable, we all assembled at Doncaster on the Sunday morning ready for the eagerly awaited flight. Pre flight planning and briefing over Taff drove us to the aircraft for our flight to Dunsfold and back.

After an uneventful take-off all was progressing well as we climbed away from Doncaster and after a short transit down to an area just north of Peterborough, Bill Perrins started to carry out a practice display prior to him doing the real thing at Dunsfold. During the display the pilots noticed that the hydraulic pressure gauge was reading lower than it should be. I had a look through my periscope at the under surface of the aircraft to find that the starboard undercarriage door was not only drooping slightly but was getting progressively worse. Martin abandoned the practice display and elected to fly back to Doncaster. We had just turned north for our transit home when the hydraulic pressure recovered with the pressure gauge reading normally and the starboard undercarriage door then closed flush with the wing surface as it should be. Thinking that all was now well we turned back south again to continue on to Dunsfold. Only a few minutes after turning south Martin noticed that the hydraulic pressure was starting to fall yet again. Because it was continuing to fall we elected to lower the undercarriage whist we still had enough hydraulic pressure to do so. Rather slowly and reluctantly the undercarriage came down and after what seemed like an eternity all the indications were that the wheels were safely down and locked. Meanwhile I was on the radio keeping Doncaster informed of what was going on. Having listened to the weather for Doncaster airport and hearing that the crosswind was quite excessive we elected to divert the aircraft to an airfield which had a longer runway and less crosswind. It was all starting to get just a bit anxious and so with Martins permission I declared an emergency on the radio and told Doncaster that we were diverting to RAF Coningsby in Lincolnshire which had a suitable runway length and facilities to cover aircraft in case of emergencies.

Setting heading to Coningsby, we were eventually handed off by Doncaster air traffic control to the Coningsby controller.  RAF Coningsby is normally in a stand-by mode at the weekends although it can be brought to full active mode within a few minutes should the Typhoons which are on stand-by there get scrambled.  Because they were in a stand-by situation and not anticipating any Typhoon aircraft scramble, the fire section were using their stand-down time to carry out a training session on the airfield. In the middle of their training they got a message from air traffic control to tell them that there was a Vulcan inbound having declared an emergency with a hydraulic problem. Suddenly their training session became the real thing. We meanwhile, with an ever decreasing hydraulic pressure, continued with our landing procedure. Two of the services that are operated by the hydraulic pressure are the wheel braking system and also the nose wheel steering facility. With the hydraulic pressure at the low level it was it was debatable whether we would have sufficient pressure in the system for the brakes to bring the aircraft to a halt before we ran out of runway. However, we do have a back-up system for the hydraulics. ‘Oh no’ I hear you cry. He’s going to get all technical again. Ok, yes I will be, but only for a few sentences I promise.

Once again we have to cast our mind back to what 558 was designed to do. Her mission in life (death) was to drop bombs on the enemy. To do this, it would have probably involved her flying through enemy anti-aircraft fire which could possibly have seen the hydraulic system knocked out of action. The bomb doors are operated by the main hydraulic system and if there is no pressure to open them and subsequently drop the bombs then the mission will all have been a waste of time. Consequently a back-up system was installed called the Emergency Hydraulic Power Pack (EHPP) which is a electrically driven hydraulic pump installed high up on the bomb bay starboard wall. This was designed for two purposes only, to open the bomb doors in an emergency so we could drop our bombs and, secondly, to provide emergency hydraulic pressure to operate the wheel brakes after the subsequent landing. That’s it. Lecture over!!

As Martin successfully flew us onto the runway Bill Perrins streamed the big brake parachute. I could see from looking through my periscope that the fire engines were following us with their blue lights flashing but more importantly, that the parachute had deployed successfully. All very dramatic. Because we had such low hydraulic pressure after using what little hydraulic pressure was left to lower the landing gear Martin applied the brakes in one continuous braking action as per the book until we trundled to a halt.  We knew that we could always bring the EHPP into action should the need to use the emergency braking system arise but there was no need for that on this occasion.  Unfortunately, by the time we had come to a halt we had run out of every last drop of hydraulic pressure and the gauge read ‘zero’. This presented a bit of a problem because, as I mentioned earlier, the hydraulics control the nose wheel steering and now we couldn’t turn the nose wheel to vacate the runway.  With no option, we had to shut the aircraft down on the runway. On opening the door I was met by Sgt Steve Parsons and his fire crew who set about making the aircraft safe by chocking it to prevent it rolling either forwards or backwards. Immediately I got out of the aircraft, I could see a steady stream of hydraulic fluid pouring onto the runway from just aft of the nose wheel area. Steve and his team immediately set about putting drip trays and absorbent paper towels around the area to catch the majority of the fluid to prevent any lasting damage to the runway service. I must say that I was so totally impressed with everything that Sgt Parsons and his fire crew did for us and I’d like to thank them not just from a personal perspective but also on behalf of the VTTS management.

Now that we were safely on the ground and chocked, Martin had to start ringing all the people who he thought should know. Most were contacted but I’m sure that there was possibly one or two who were inadvertently missed for which we apologise. I then contacted Phil Davies who was at a wedding to let him know that disappointingly, he would not be flying the following day. Having made all our calls the firemen invited us back to the fire section for us to have a much needed cup of tea while we waited for Sam Evans and Ray Watts to arrive from Doncaster to take control of the situation. Once they had arrived we then bade farewell to Sgt Steve Parsons and his team and drove back up to Doncaster to collect our cars and wend our way home.

It had been a long but interesting day. Not the sort of day I had envisaged, but one which stirred the old grey matter. Anyway, it all turned out to be a safe day and that’s all that matters. It was disappointing that we never made either of the Dunsfold displays and we feel for the crowds that had turned up to watch us. We now have to let Taff and his team do their work at RAF Coningsby and hopefully get 558 repaired in time for us to fly to Portrush in Northern Ireland on the 4th September.

This blog has been a bit different from my previous ones. If I’ve been a bit too technical for some of you I apologise, but I do know that there are those of you who do like to know just that little bit of how the aircraft works and is operated, so it is with them in mind that I’ve tried to include that, to explain just why we take the actions we do when faced with an emergency.

And finally. You will recall that it was envisaged that when Martin Andrews (Junior) became qualified as my replacement I would then retire. Unfortunately the display at Bournemouth which was going to be Junior’s final assessment was, as mentioned previously, cancelled.  This meant that he would have to be checked out on a future display trip.  As you all know Junior is still in the RAF and has been posted away from Waddington with effect from 30th August  before he could do his assessment  and, consequently,  is not available to fly for the next six months. This means that he cannot qualify as a Vulcan AEO until next March at the earliest. If I was to continue with my plan to retire after the last display in a couple of week’s time that will mean that the VTTS will only have one AEO, Phil Davies, on the books. The reason why we have always had two AEOs, is to provide cover for each other should one become ill or not be able to fly for whatever reasons. Leaving the VTTS with only one AEO would not be a an ideal situation and so I was asked by our Execs if I would reconsider my intended retirement and continue on until such time as Junior becomes qualified. I have now agreed to stay on, so all of you who thought that you had finally managed to get rid of me – think again. I shall still be around to annoy you. The pipe and slippers are put to one side for at least six months or so and will only be brought out for me when Junior comes of age as a fully fledged AEO. Then you will you be all be able to breathe a sigh of relief as I finally hang up my flying suit and helmet.

That’s it for this time. 

Happy landings.

Barry Masefield


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