fv1609

Welcome. Did you spent much time on Humbers?

Not sure what you mean, can you show us the final entries?

Interesting link thank you. I don't know what people make of the accuracy about vehicles that they have a special interest in? As far as Pigs & Hornets go, it is perhaps best to say it is not great and no Pigs do not have coil suspension :nut:

Welcome Leighton. Yes I used to have a soft spot for the No.17 set, in fact I wish I still had them. But amateurs do like to meddle with things! I've been licensed a while but your call sign I saw on another post is a lot older than 1972?

Yes I was fascinated when I came across these investigations & having been sitting on it until I had a reliable internet connection. Equally fascinating is File No. XXIX-54 that investigated an alternative solution to the HT problem, not just reducing it but dispensing with HT altogether by means of "ignition oil". Although the idea worked it failed due to problems with temperature especially cold starting.

Yes Alec it was amazing to see some of the complex thought processes going on but missing the ignition issue. These tests were as the result of the activities at the Junkers plant in Dessau in conjunction with Siemens and Beru. The plug below was the Beru solution to the problem. This design also reduced the liability to oil-up after long periods of idling or aerobatics. Tests over 26 hours with varying loads showed the plugs to be trouble free. Seems curious that this system did not catch on?

Yes well done Derek this is indeed a sparking plug! The point is that it is a low voltage system. The problem being that at high altitudes the air density is decreased which causes problems in 10kV systems with the spark jumping the insuation in the plug itself or in the HT leads, especially after long operating periods. In this plug the spark doesn't jump an air gap but "glides" along the surface of the insulation ceramic. This can be achieved with voltages as low as 400-1000 volts. The source of this is the Combined Intelligence Objectives Sub-Committee File No. XXIX-53 15th August 1945. Diagram to follow.

Well hunted down Terry http://www.lightspeedengineering.com/Technicalities/sport_aviation95.html But this is not a high voltage system, but you are right it is ignition related but Degsy got there first.

That's not the specific issue Terry that this is designed to overcome.

That's not something I had not thought about RH. It seems a valid point but it is not related to this device.

Yes I thought it would all be over on the first night. Not St Elmo's fire as such but on a very very small scale there is a sort similarity.

To the device Andy

Electrical Derek

Alec not that sort of issue.

No I meant that ionising leads to conductivity that causes the problem.

A conductivity issue

OK here's a clue. The items are special & novel way to overcome a problem related to the conductivity of air.

Don't know Wally but this is not related.

Nope not that Richard

In fact this is a lower voltage than one might have expected

Lauren this is how something behaves in less dense air & how it effects propulsion rather than aerodynamics

Sorry missed you there Wally. It is not to do with the engine air mixture itself, but how the air outside the engine causes problems & these devices seek to avoid these problems by doing some else differently.

Good thinking Lauren nothing to do with static but the problem comes from low air density, so the design of this device allows a system to be used that circumvents the problem by doing something in a different way.

Interesting thought Richard, but everyone is thinking of exotic explanations. It is much a more basic problem concerned with flying at this altitude.

Not that Gordon, Wally already suggested it in #77