Vulcan BMk1 NBS and Memories
Vulcan Bombing Accuracy
Hey - you oldish and bold ex Vulcan crew members please answer a question that has been bugging me.
For a while I was Senior Vulcan B1 TP at Boscombe Down. In between weapon carriage and release trials I spent a slice of my life trying to marry the various black boxes and coupling units of the NBS to each other. It was quite a challenge with the Mk 10 auto pilot involved both for bombing and landing approaches. Testing of all conceivable max rate runaway conditions approaching the manoeuvre envelope boundaries kept the adrenalin flowing.
What was the eventual fix to prevent the long period directional phugoid which I discovered one night when on a long haul Navigation Bomb System (NBS) assessment. The stars kept slowly going back and forth with about a 6 degree swing with cockpit instruments all showing steady heading.
Closer examination revealed the source of the problem originated with the compass which had precessional control over the Directional Gyros (DGs) to keep them aligned. Acceleration effects on this alignment system caused the Phugoid lasting about 5 mins per cycle.
This all happened a few months before the first Vulcan Sqdn at Waddington was due for the first time to enter the USAF annual bombing competition. My temporary fix was to have the Sqdn select DGs having negligible natural precession for fitment to the co pilot's panel. Existing switching then permitted use of this DG without compass correction as the heading input for the NBS during critical phases of bomb runs. The Captain retained his DG slaved to the compass. The compromise worked well but was only accepted as temporary.
I recall flying a Vulcan into Waddington to give the competition crews a briefing. The only pilot I remember at Waddington was Sqn Ldr Podge Howard who later, or was it earlier, banged out of that Vulcan at London Airport together with the C in C of Bomber Command. Where is Podge Howard now?
Anyone know the Fix?
And one other question.
At Boscombe we wanted to know the effects of loss of up to 2 Powered Flying Control Units (PFCUs) particularly related to landing approaches. The effects of having two roll units out on one side caused a high degree of cross pitch with roll input and cross roll with pitch input.
Were squadron pilots allowed to shut down PFCUs for training?
Enough technical stuff!
Here is an interesting extract from my memoirs.
One flight with the OC involved yet more weapon release trials from the Vulcan. We had completed some releases into Lyme Bay, a restricted area off southern England when I noticed an aircraft carrier in the area close to where we had been dropping a bomb load. We both thought it most irregular for the carrier to be within our restricted area, so I decided to have a closer look. And what better way to have a close look than to make an approach as if to land on the carrier.
I lowered the undercarriage and approached the deck from astern. As we closed on the carrier we were suddenly aware of smoke and muzzle flashes from some of the carrier's guns. I immediately developed a strong desire to leave the vicinity but not before flying in to about super-structure height. I then ran the engines up to full power as I pulled up into a steep climb away.
It turned out that the carrier was in the area for gun firing training. The OC later had angry words with the Navy and the Captain of the carrier who said we had them worried for a while. Subsequently, we were always carefully briefed on naval ship movements around our dropping area in Lyme Bay.
I flew the Victor occasionally. The feel of this aircraft always gave me an impression of fragility. Control reaction, wing and tail bending combined to cause one to take care with gross manoeuvres. Handley Page had tried hard with cockpit design but it seemed overly complicated compared with the ruggedness of the Vulcan. Perhaps the cohesive structure of the Vulcan made the difference. The Vulcan felt like a fighter having excellent manoeuverability. The Victor, with its lower rates of roll and pitch, was more complex in its manoeuvre characteristics. Now, as an experienced test pilot, I became very aware of these subtle comparisons and pondered about the reasons for such differences.
Then there was the Comet 2C. There could not have been a worse flight control system. It was straight spring feel with exceptionally high breakout forces. Our stipulation that the system be changed to Q (1/2 roe V squared) feel followed which must surely have been appreciated by RAF crews.