RAMP RAMBLINGS……….By Keith Bradshaw. Photos Steve Jeal and Keith Bradshaw
Welcome to the first edition of Ramp Ramblings for 2017. Hope you had a good Christmas and may I wish you all a belated Happy New Year. This is the time of year for looking forward and we can certainly do that with a number of important anniversaries coming up. This year will see the 70th anniversary of the first flight for both our Ambassador and Hermes in July and September , the 50th anniversary of the first flight of our Trident on 2nd November and on 20th August, the 40th anniversary of Concorde arriving here at Duxford ! So it looks like lots of birthday cake will be consumed this year !
Ambassador basking in the Duxford sun.
We haven’t had a “Technical Tidbit” for a while so let’s kick off this edition of Ramp Ramblings with a look at the ”All flying tailplane.” In the early days before the speed of sound was approached aeroplanes were controlled in pitch by having a fixed tailplane with a moveable elevator. This was fitted on the trailing edge of the tailplane and was manually controlled by the pilot. The elevator could be offset from its zero position by applying elevator trim to enable any out of balance forces to be corrected so that the aeroplane flew straight and level without the pilot having to apply constant elevator deflection. This system worked fine until aircraft began to get faster and approach the speed of sound, when a problem known as Mach nose tuck occurred which made the aeroplane pitch down as the speed increased.
On an aircraft wing all the lift can be said to operate through a point known as the Centre of Pressure. This lift is normally perfectly balanced by the aircraft weight acting in the opposite direction through the centre of gravity. However as the speed increases this Centre of Pressure is pushed back along the wing by the transonic shock wave from the oncoming airflow. The balance between weight and lift is disturbed and the wing and hence the aeroplane will begin to pitch nose down. To counteract this the pilot will have to apply more and more nose up elevator trim. However as we have seen this is done by offsetting the elevator, so as the trim moves the elevator to bring the aeroplane nose up this leaves less and less elevator travel for the pilot to use to manoeuvre the aeroplane. Not a good situation to be in. So how was this problem overcome? Back in the early to mid- forties both the UK and the US were working on aircraft designs capable of exceeding the speed of sound. In the US the Bell company was working on its Bell X-1 which originally featured a conventional tailplane/elevator set up. However in 1942 the Miles aircraft company, based near Reading in the UK had started work on their M.52 research plane that was designed to be able to exceed 1000mph.
MILES M. 52
The Miles company had realised the Mach nose tuck problem was a biggie and had come up with a novel way of solving it. Simply put instead of the trim system displacing the elevator it would move the entire tailplane , leaving the pilot with the full range of elevator movement to control the plane. The UK and US governments at the time decided that they should share their high speed research secrets and a delegation from the Bell company visited Miles and saw the results of their labours. On returning to the US the Bell X-1 was immediately made top secret and Miles were not allowed access to any data! With the M.52 very close to first flight the Government cancelled the project in 1946. One year later, in 1947, Chuck Yeager became the first man to exceed the speed of sound flying the Bell X-1……… now fitted with an all moving tailplane!
BELL X-1 (photo credit NASA)
Miles may have been forced to pull out of the race but the legacy of their development of the All flying tailplane, now known as a stabiliser or trimmable horizontal stabiliser, has been carried on to this day with all fast jets being fitted with this system. The tailplane is now trimmed by an automatic system called Mach trim so the pilot no longer has to worry about Mach nose tuck.
So back in the present what’s been happening around the ramp? Well prior to Christmas the Sunday team finished off patching up the Britannia flaps and got them all painted in primer ready for the move into the hangar in the new year. So early January saw a combined team from DAS/IWM/Monarch attempt the move into Airspace for two weeks painting.
Well we were almost snookered at the first move when the landside/airside fence posts were found to be well and truly stuck in the concrete, even a forklift could not pull them out.
Well after some head scratching the Monarch guys wound the flaps up, with a few volunteers also putting their back into it.
Then with some very skilled tug driving by the tug driver he managed to thread the Brit around the posts and out onto the taxiway.
Two weeks very hard work with seven day working saw all the yellow, the black and the grey undersides of the wings receive several coats of bright new paint. With all the different DAS “shifts” working together on a roster devised by Project supervisor Chris it all went surprisingly well, with only a few minor problems.
So two weeks and numerous tins of paint later she was ready to leave the hangar for the short trip along the taxiway to meet her public once more.
Unfortunately the Gods were not with us and the rain came down to greet the Britannia on it’s journey back to the line up.
The rain got heavier as the Britannia made her way up the runway.
However the following day the sun shone down and the Britannia looked fantastic in her new paintwork.
With just a few odd jobs left to finish off, weather permitting , should see her spick and span for the first airshow at the end of May. For the dear old Brit it was indeed a new dawn. Well done all concerned from DAS the IWM and Monarch.
So that’s the story of the Britannia what’s next? Well the day the Brit rolled out of the paint shop the Concorde was closed to the public for two weeks for the long awaited refit to start. Prior to Christmas the IWM had provided a new uprated power source to the Concorde parking area, so now the DAS electricians , Ian and Alan, had to run this onto the aircraft and rewire the “ring main” so it can support all the new displays which will eventually be fitted. All the non- original ( for this aircraft) Concorde grey leather seats have been removed ( available to buy from Dermot on email@example.com) and the old original seats for the test engineers are being restored and will be refitted when complete.
By the time Concorde is re-opened it will also be sporting new floor covering throughout and hopefully have its Ice station position refitted in the cabin. This was used with CCTV to monitor the ice build up on the wings during flight testing. Les, the DAS welder, has done a grand job of cutting and shutting the access stairs to make them more user friendly when the visitor flow is reversed to provide entry at the rear and exit at the front. This will hopefully cut down on the queues to view the cockpit holding up access for visitors on the steps. A whole new CCTV security system is also being installed. We wish to thank the IWM for their assistance in these major works.
Elsewhere the donated ground equipment we have is being cleaned up and repaired ready for repainting hopefully by the May airshow. The Ambassador prop spinners were beginning to look a little tatty, so they were removed before Christmas for refurbishment. This now complete and they will soon be back in their rightful place in front of those magnificent Centauras engines.
As I mentioned last month this June 18th, Father’s Day, we will be running a special event here at Duxford called the AIRLINER DAY. This will celebrate all things airline and airliner, plus some other attractions, and is being run as a fund raiser for the British Airliner Collection. All the airliner cabins will be open as per normal air show days, plus bookable cockpit visits will also be available. The British Airways Brass band will be providing music, there will be a selection of Classic cars plus a display of ex USA Police cars fresh from the London New Years Day parade. Military vehicle rides will be available plus a departure re-enactment using the Ambassador as a stage. Many airline staff associations have been invited and their members asked if possible to wear their old uniforms to add to the flavour of the event. We are also hopeful of some current airline involvement. A small static park is planned along with pleasure flights in the Rapides of Classic Wings, there will however be no flying display. The DAS shop will be open selling its usual selection of books, models and memorabilia. Many other attractions are in the planning stage including the chance for a member of the public to sit in the cockpit of Concorde and operate the controls during a nose droop demonstration. We plan to have a dedicated banner on the website soon so you can check back there for regular updates about what’s happening on the day.
To finish off a little view on how things have changed over time in the airliner business. In 1959 Qantas set a record, at the time, for its fastest ever Sydney -London flight in just over 5 days using a Super Constellation. Next March Qantas launch a non- stop Perth-London flight using its new Boeing Dreamliner with a journey time of just 17hrs. Change indeed !