After the BBMF Lanc was resparred some years ago, BBMF was quoted as saying that her fatigue life was now way beyond what the projected availability of AVGAS was and it’s that fact that will ground her first.
On the basis of the Friends of the Earth petition to the US EPA in Nov last year to regulate AVGAS, and then Continental Engines President’s Rhett Ross statement in Feb this year that they were concerned of the future availability of AVGAS and were working on a diesel engine for GA use, what’s the implications of being able to run Merlins, Allisons, P&W etc’s in warbirds, in what now seems the near future rather than 20-30 years down the road……?
Found this worrying article as well…..:eek:
http://www.epi-eng.com/aircraft_engine_products/demise_of_avgas.htm
By: Arabella-Cox - 29th July 2008 at 21:52
There is also a ‘new generation’ of aircraft engines around, i’ve seen a brochure and photos of one of the pre-production ones here in the UK. The engine is a development of the Wankel rotary system but is supposedly more efficient. The engine is in the process of certiication i believe (currently a single rotor system is on a microlight). The great advantage of Wankel engines is that they can be turbo compounded, a turbo can be attached to the crank to increase the power for a smaller engine size. These engines are also meant to be able to un on any fuel.
By: J Boyle - 29th July 2008 at 14:56
…and then Continental Engines President’s Rhett Ross statement in Feb this year that they were concerned of the future availability of AVGAS and were working on a diesel engine for GA use….
This has been a concern in the GA world for many years.
It’s not a “world runnining out of oil” concern…
Simply put…jet fuel/diesel is more readily available in may parts of the world than AVGAS.
Since trucks, generators, and turbine powered aircraft already use the stuff, it’s available most everywhere.
Imagaine the task of laying in a rather limited suply of AVGAS in remote locations (like the bush…or even larger places like St. John’s, Newfoundland for the now few piston planes crosing the Atlantic) for the exclusive use of a few aircraft who might only buy a hundred gallons at a time.
Diesels are approved for a number of GA types and the list will only grow,
By: low'n'slow - 29th July 2008 at 13:54
Ultimately the availability of 100-octane, leaded fuel (avgas) is governed by the continuing demand from the General Aviation sector.
No matter how thirsty warbirds are, they are relatively few in number compared with tens of thousands of Cessnas and Pipers and the like.
While they are flying, there remains a (reasonably) viable business case for continuing to produce Avgas.
The relatively low volume of Avgas production also gives it a reasonable case against environmental issues too. The major reason for the removal of lead compounds from road fuels (remember 4-star and 5-star?) was because of high lead accumulations in the atmosphere at ground level at major road intersections.
As aeroplanes fly around, what little lead-laden fumes are generated are pretty thinly dispersed. You’re more likely to get lead in your bloodstream from some Victorian piece of lead plumbing!
While diesel engines have been used recently in light aircraft, the fact that the biggest diesel engine producer is currently in financial trouble, isn’t likely to encourage too rapid a change-over from gasolene. In fact there’s a good supply reason to stay with petrol, as every other form of transport is fighting over diesel fuels, shoving the prices ever-higher!
Some modern engines such as the Rotax, are designed to run on unleaded ‘mogas’ type fuels (and in fact some vintage engines can handle it too). However there are some potential problems in using it.
It is more prone to vapour-locking at higher ambient temperatures and the recent introduction of ethanol into some ‘mogas’ supplies can potentially make that issue even worse.
Having had a vapour-lock on an aircraft engine on climbout 😮 I’m back to being a keen advocate of Avgas on my aeroplane, even if I have to clean lead deposits off the spark plugs a bit more often!
I guess if leaded avgas were to be phased out, there might be a case for adding lead compounds, as classic car owners do as ‘octane boosters’. But as the EPI article points out, some of these compounds are themselves much more toxic than lead-compunds and there would have to be a bit of testing done to ensure the additive didn’t attack fuel system or engine internals.
Although the article is alarmist – I’m sure that the financial case for ongoing production will keep supplies of 100LL going for a another 20 years at least.
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July 29, 2008 at 1:21 pm