Sea Vixen Fuel Management
 

Apparently at least one pilot managed to flame out both engines on a Sea Vixen due to him failing to "select the right tanks".

I thought that manual fuel management went out with Lindbergh, does the Vixen really require the pilot to manually select tanks, anyone know ?

Chapter 2, para 4a.......

Sea Vixen FAW Mk 2 Pilots Notes - SeaVixen

A very good friend of mine, sadly no longer with us, told me that he only really understood the Vixen fuel system when he became an instructor on the sim. This was after doing a full tour on a carrier.

Many thanks as ever Orac, strangely I have Blakes 7 playing in the background as I type this.

Reading those pilot's notes it becomes obvious that the story I recall was caused by the pilot turning off the booster pumps with a resultant flameout when the gravity feed emptied the number 1 tank. Not sure why he would do that though.

Anyhoo, thanks again.

There were plenty of other aircraft that could flame out from fuel starvation with tons of fuel remaining, the F4 for one.

Now how on earth can anyone manage to do that?

Fonsini
I worked for a Chief who told me that a SV flipped over as it came in to recover onboard a carrier. It inverted rolling left to right and ended up crashing into the sea upside down on the stbd side of the ship adjacent fly 1.
This he maintained was somehow due to an error in fuel tank selection late upon approach.
No idea on any further detail but this would possibly have been on the Eagle, or Victorious.
Terrifyingly adjacent to the deck party, hence him remembering.
This being a tale long remembered but deffo involved fuel tank selection on finals- perhaps someone remembers the full story?

Sea Vixen tales littered my training in the FAA and they must have been horrible to be involved with in cold hard reality they killed a lot of good men.
Off thread, I often think would have been how useful to the FAA if the UK had been involved in Vietnam on the US side, or the 6 day war on either side, or even the Falklands on our side?

Hmm, now I'm confused, so there is an option for tank selection.

Always hate to hear about those crashes even when there is something to be learned from them. I can't think of a more terrifying job than sitting in the "coal hole" of a Sea Vixen during a carrier landing.

H.Peacock

Try inverted flight or even a bit of zero g mixed with a bit of negative when trying to wring the best you think you can from the JP's limited performance:🤔
Leave the throttle wide open (one doesn't have a lot of choice here!) and wait 30 seconds and you will find out!:😳😳
MB

Ah, I see. Zero/negative g v recuperator capacity. I thought you were referring to fuel mismanagement, ie pumps and tanks!

I have just been reminded that I once had a Sea Vixen parked outside my office while they worked out how to convert it for pilotless flight. My previously mentioned good friend told me that he thought that the fuel system was far too complicated to be operated remotely. However, as far as I know, they did successfully use the Vixen to replace the Meteors so they must have been able to do it.

I have yet to find a reference which confirms unmanned operation of the Sea Vixen when converted to the D.3 Drone. Evidently they could be controlled from the ground but it would appear that a standby pilot was onboard (to operate the fuel system?).

Targeting at Llanbedr

Sea Vixen Drone (D3) Era - SeaVixen

Hangarshuffle, reading through the accident listings the only one that mentions fuel transfer problems on a deck landing is XJ853 of 892 Squadron on HMS VICTORIOUS 8th February 1961. Fuel failed to transfer from starboard drop tank and on landing the overload from the full tank caused the oleo on that side to collapse. A number of other aircraft are mentioned lost due to transfer problems, but not in the vicinity of the carrier.

One hell of a loss rate, 54 airframes of the 145 built, not including both development prototypes lost, making 56/147.

http://www.seavixen.org/images/templ..._892_prang.jpghttp://www.seavixen.org/images/templ..._892_prang.jpg

Fon - you didn’t identify the particular accident, but you indicate there may have been a simple cause …. I don’t think there was anything simple about the Vixen.

I didn’t fly the Vixen but I was around when they were. ISTR one of the early problem areas we heard about, was if you had a double generator failure. This could be brought about inter alia by low level high IAS occasionally causing a belly panel to detach along with necessary electric bits. The catch was you then had about 20 minutes flight remaining before the batteries failed. When that happened there was nothing left to push the fuel to the engines so not a lot to prevent a double flameout through fuel starvation, and not a lot you could do about it. I don’t think this precise situation had been anticipated during development so it was a bit of a surprise to the squadron boys when it first happened on the Mk 1. I assume remedial modifications were quickly put in place, to mitigate the immediate problem, including for the Mk 2. The Ram Air Turbine only provided hydraulic power. I wonder if they ever considered it for electrical generation.

Moving on from ORAC’s link to the Vixen Mk 2 PNs dated 1970, and for lack of any more specific answer (so far) to your question, here’s a most succinct quote from the same seavixen.org website, by the famous Jon Whaley, who is still current on type -

“Fuel management was one of the Vixen's highest workload for the crew. There are FOURTEEN tanks if you were carrying two drops, a total of 13,500 lbs or 7,670Lts. You had two fuel gauges, one for each side. You or normally the Obs could cycle the gauges to show the contents or sum of tanks 1 - 4. The fuel in the Pinion tanks and Drop tanks was not gauged. (The Pinion tanks were only on the Mk2 being extensions to the Mk1's booms in which fuel could be kept). Air pressure from the engines pushed the fuel from the drops into the No 2 & 3 tanks. To pump all this about, there are 10 main Booster Pumps and 6 auxiliary pumps. If I tell you that the P/Ns have 16 pages on the fuel system, you'll understand why I don't go into much detail. Fuel management was critical.”

‘Nuff said ? ..... LFH

ps .............. including well over 50 aircrew.



......................

Sounds like an improvement on the Tornado F3......

Not Sea Vixen, but about unusable (unreachable?) fuel.


My dad was leading a group of F-4s from Viet Nam to California for depot-level maintenance. One of the guys ejected over the Pacific after fuel starvation despite a full drop tank.


From what my dad told me, they were always supposed to burn off the center line drop tank first as it used bleed air instead of a pump to move fuel up. If you waited too long, ice could form and block the fuel line. No fuel. No thrust. In a Phantom that means the glide ratio of a rock.
At least they had plenty of time to radio for SAR to come get him.


Side note - the fuel system for the Sea Vixen sounds like a nightmare.

Mechta,

I believe you are right in thinking that the Sea Vixen drones never flew without a pilot on board. I worked on the project at Brough in the 1970's, as we were at that time the Sea Vixen design authority as part of Hawker Siddeley Aviation. I assume that was because were were also design authority for Buccaneer and Phantom, so must know something about carrier borne aircraft. The drone control pack that sat in the cockpit in the observers station was known locally as 'the iron man' I made several trips down to Tarrant Rushton airfield to liaise with Flight Refuelling who were doing the majority of the design work. I can remember watching one of the aircraft weave its way down the runway under the control of the ground operator.
There was considerable debate about the safety of the system fitted and what was the preferred method of destroying the aircraft if control was lost. There were a number of explosively driven actuators that put in full aileron, elevator and rudder control deflections, independently of the main drone actuators. I seem to remember the plan to minimise the potential cone of impact was for the aircraft to be pitched up into a spin rather than pitched down into a spiral dive.
I don't know why the project never came to fruition but I believe there was some concern about the extent of corrosion in the airframes and there was a possibility of the aircraft breaking up under the loading of the planned evade manoeuvre that the aircraft was to perform when approached by the missile being used against it.
Like a lot of MoD sponsored projects at the time it just seemed to drift along with no clear end in sight and then faded away with no feedback why. Then again maybe I was in such a lowly position in the organisation in those days the management never told me such things.

Walbut

Here is what I recall of the "incident". It was a 4 ship on bombing practice, our man was tootling along quite happily in the slot position when suddenly there was a double flameout accompanied by all the bangs associated with disrupted airflow in the inlets. The Vixen dropped out of formation and began to lose altitude, the Obs commented that the pilot's hands were suddenly a complete blur as he began switching tanks and throwing switches to find some fuel, eventually succeeding and performing an air restart. In the debrief the Boss chided him for poor formation flying. The fuel mis-management and flameouts were never mentioned by the aircrew as I assume this would have resulted in a write-up of some kind.

Following a brief and exciting association with the Sea Vixen, I concluded that it was an aircraft where the adage "if I can start it, I can fly it" did not apply. The parking brake being the problem.
Any flight without a fuel pump failure was a success. (was it 10 switches on the gang bar to get them on, but not so many to turn off after flight, and nearly as many white 'dolls eyes')
The inboard engine would flame out at high altitude with any slight disturbance; I didn't know that, so back to re read the pilots notes - a short two line entry explained the problem (pt 3, 2, c).

Then there was mod xxx, which enabled the approach speed to be reduced by 5 kts; wow what great aerodynamic achievement was this. None could be found on the airframe, but the small print in the tech log explained that if the bubble canopy was fitted then with a higher seat position the speed could be reduced.
Transonic flying was always full of surprises; the control system changed gear. A slight wing drop approaching M1.0 (pilots notes) was invariably a roll through 180deg followed by a supersonic recovery.

A few years later I was able to exchange experiences with one of the DH test pilots. After several beers we concluded that the difference in our views was due to the intervening years and experience; his stopped with the Vixen, mine started with the Lightning.
The Sea Vixen was a very good aircraft for its time, and in latter years enabled me to enjoy a rewarding love-hate relationship. Sadly my aircraft had to go to the drone factory.

I believe one of the reasons the Buccaneer fuel system was originally designed to have no electric pumps was because the Navy had such poor experience with the Sea Vixen multi pump system. Two were eventually introduced to transfer the bomb door tank fuel but as far as I can remember they were reasonably reliable.

Walbut