Interesting to see the method of starting the Tomtit. My late father used to tell me about the times when he flew a Tomtit. His carried the preceding serial number to the one at Shuttleworth. His log books show that he flew it after starting single handed using the method preferred at the time rather than using the Armstrong method and one or more assistants. He often used to say to me, “I don’t know why they insist on using the Armstrong, propeller swinging method at Shuttleworth when there is a simpler way.” I think I remember seeing the Shuttleworth engineers using the Hucks starter too. This he thought a waste of time too. His method was to set the magneto switches to ”off”, prime the engine with a few turns of the propeller, set the propeller to top dead centre or just a wee bit after, remove the chocks, Climb into the cockpit and flick the switches to “on” and the old reliable Mongoose would fire up first time and every time. The only other required procedure was to set the propeller after switch off to a position where the bottom plugs would not oil up with any oil residue obeying the force of gravity. This ensured that when the Tomtit was needed the following morning the plugs would fire first time. His method was the only way one could start it without assistance after a forced landing in a hay field due to bad weather. I would be interested to know if anyone else has a view on this. John Shipman.
By: John Shipman - 11th September 2012 at 20:27
Tomtit starting method
Most interested to see the comments re starting the Tomtit with the magneto. Father did ask Shuttleworth about trying his method but they were not interested. Are they more open minded or adventerous today I wonder? Or maybe there is a good reason why they don’t start it this way. We used to have to swing the metal props on the Cessna 150’s most of the time at the flying school where I got my PPL. We were shown the correct way but there is always an element of risk in any task like this one. John Shipman
By: Stan Smith - 7th September 2012 at 06:49
Yep. That’s probably me in the front doing the Boss’s type rating.
By: Wessex Fan - 7th September 2012 at 01:57
Irish Air Corps Cadet
Ref post #6. When I had finished assembling the aeroplane at Baldonell and test flown it, I did a type rating for the C/O ,Brig Gen Ralph James and he did the display with it at their Airshow a couple of days later,. I also did a type rating for the CFI, Commandant James Gavin. As far as I know the aircraft was to be kept in airworthy condition and the intention was that it would be flown reasonably regularly. Given the “current economic situation” all such schemes are subject to change I suppose. Any Irish Forumites care to enlighten us??
Stan
I was lucky enough to see the Cadet fly at Baldonnel in 2007. In a much later conversation with Ralph I did ask about when we might see the Cadet fly again. At the time he told me that they had been experiencing problems with the magnetos, he also made comment on the difficulties the corps had in operating such an aircraft from a health and safety point of view. A specific point mentioned was hand swinging the prop and how you instruct an airman on a safe method of starting the engine. (I hope you all agree that hand swinging a prop is an inherently dangerous operation) All this was in the context of the operator being a modern military air component that obviously does not generally operate 1930’s aircraft.
As he was the chap in the hot seat if something did go wrong, I could see his point. The conversation was some years ago. Since then I have heard nothing new about flying the Cadet.
I have attached an image of the aircraft, taken at the Irish Air Corps family’s day.
By: Stan Smith - 7th September 2012 at 00:14
Ref post #6. When I had finished assembling the aeroplane at Baldonell and test flown it, I did a type rating for the C/O ,Brig Gen Ralph James and he did the display with it at their Airshow a couple of days later,. I also did a type rating for the CFI, Commandant James Gavin. As far as I know the aircraft was to be kept in airworthy condition and the intention was that it would be flown reasonably regularly. Given the “current economic situation” all such schemes are subject to change I suppose. Any Irish Forumites care to enlighten us??
By: Melvyn Hiscock - 6th September 2012 at 19:49
Radials tend to fire in alternate order, so 1, 3, 5, 7, for first rotation of the prop and 2, 4, 6, for the second, or at least the Warner does. I have to do the tappet gaps every 25 hours on the warner and so it is an easy job to simply mark the prop with magic marker so that when the mark lines up with the cylinder and you are getting compression, it is the one you need.
This is the same starting system as used on the Fokker DVII with the Memorial Flight. Position the prop, wind the mag and off she goes.
By: Creaking Door - 6th September 2012 at 15:29
You can certainly ‘feel’ about where top-dead-centre (TDC) is on most engines if you turn the engine forward; you feel the compression building up resistance and then it suddenly goes ‘slack’ when you pass TDC. The difficulty is knowing which cylinder you’ve got TDC on (and that must be even more difficult on a seven or nine cylinder radial).
I’ve heard of starting-magnetos (didn’t even the early Hawker Hurricanes have them?) but hadn’t really appreciated their function before; do they work on all the cylinders or only one?
By: hampden98 - 6th September 2012 at 15:13
Here is a video of the RAAF Museum’s Sopwith Pup replica that is powered by an Armstrong Siddeley Genet Major that is started in much the same way as Stan has described. The only minor difference in this particular aeroplane is the “shower of sparks” is provided by a battery powered vibrating coil, instead of the more usual hand cranked starting magneto.
Anyone that has a Genet Major and/or parts they would like to part with, please let me know… 😀
How do you know when the prop is in the right position,
can you feel it?
By: Oxcart - 6th September 2012 at 09:42
The Genet that we fitted to the Mk1 Avro Cadet that we did for the Irish Air Corps museum at Baldonell (Casement) had a hand turn start Mag. Again the suckin part is the same but the trick is to get the required “Just past Top Dead Centre” at the right place. Turn the cockpit handle furiously and “Hey Presto!!” it bursts into song.
Was this aeroplane grounded then? I thought they were going to use it for flying displays.
By: Avro Avian - 6th September 2012 at 01:03
Here is a video of the RAAF Museum’s Sopwith Pup replica that is powered by an Armstrong Siddeley Genet Major that is started in much the same way as Stan has described. The only minor difference in this particular aeroplane is the “shower of sparks” is provided by a battery powered vibrating coil, instead of the more usual hand cranked starting magneto.
Anyone that has a Genet Major and/or parts they would like to part with, please let me know… 😀
By: Stan Smith - 5th September 2012 at 23:00
The Genet that we fitted to the Mk1 Avro Cadet that we did for the Irish Air Corps museum at Baldonell (Casement) had a hand turn start Mag. Again the suckin part is the same but the trick is to get the required “Just past Top Dead Centre” at the right place. Turn the cockpit handle furiously and “Hey Presto!!” it bursts into song.
By: Sopwith - 5th September 2012 at 21:31
Perhaps there is an advance and retard on the mags of the Mongoose which enables the points to open and create the spark as per Rolls Royce cars with a mag,which I have heard could be started by moving the advace/retard lever.Just a thought,could be wrong though.
By: Creaking Door - 5th September 2012 at 21:17
Now I’d love to see that attempted at Old Warden! 😀
I have to admit though, I’m more than a bit confused as to how this method works; where does the power for the TDC spark-plug come from when you ‘switch-on’?
The Tomtit presumably has magneto ignition and no battery so where does the power come from; the magneto needs a moving magnet or coil to generate any spark energy. :confused:
Not doubting your late father…..just interested to know the science behind this method.
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September 5, 2012 at 9:03 pm