News Researcher Looks Through The Noise To Discover Potential Risks From Jet Fuel

[Ed Norton]

The user 411A is the guy who I was talking about. He gives some of the limitations imposed when 100LL is used in engines requiring green or purple gas. Above I said red but that is a low octane formulation. Just for interest. I went back and reread some of his old posts and it was really nice. I am not a member of airliners.net but he was also a major contributer to pprune.

https://www.google.com/url?sa=t&sou...ggkMAM&usg=AFQjCNH07VoOthhQ4ONg28yazMUoXxpiNg

 

[Recovery4Me]

I lived within a zone that the flight hours were clocked. Everyone had fine blue-black dust on their homes and cars everyday from NAS, sometimes up to an inch thick from fall out from the low slung take offs. Most everyone lost some hearing (including wildlife and domestic pets) and the service practices nonstop during escalation. With such power from the jets and such, the homes shake, windows rattle and some people sleep with a set of ears (coverings for range).

So to me, any research that gets performed to assist in protection of those serving in any capacity, any peoples, or any life what so ever -bravo! Just having it out there is the first step and hopefully less kids in those areas will be sick. jmho


*edited for clarity of acronyms @Ed Norton Naval Air Station (NAS). I have lived within and lived near-by quite a few that protect our shores as well as other things.

 

[Deleted member 28403]

This is really interesting, and I would never expect something like this. Time to read up a lot :P

 

[Ed Norton]

The study doesn't seem to have been published yet as I have looked again. I will try read it when it gets published with an open mind.

NAS--- Nassau Bahamas?
One problem encountered with airports was that they were usually built away from population centers but then everyone wanted accessibility to the airport so they encroached up them then complained that there's an airport nearby.

Indeed the older low bypass and straight turbojets of the past were sooty and loud but the newer ones are very quiet and in many cases follow strict noise abatement procedures.

 

[Anarchy]

OK
I seem to remember a better solid model than this one

It is only showing the sleeve valve train and the piston con rod and crank assemblies, it isn't showing the reduction gearing on the prop end of the crank

The sleeve valves are also very schematically in the model, in the actual engines they were shaped for rapid opening for good gas flow cadency.

The sleeve valve engines had the longest service interval and time before overhaul of any of the piston aero engines. The oil was usually still yellow and clear at oil changes. Harry Ricardo, who was a great fan of sleeve valves, reckoned on them allowing an additional +1 compression ratio before trouble with detonation, compared to an equivalent engine with poppet valves. Though that advantage probably disappeared with the advent of sodium cooled valve stems.

In Bristol's practice, the two row radials were a stop gap, until the next larger capacity single row radial was fully developed. AFAIK, they never went to four row radials, as P&W did with the double wasp. Even two row radials had problems with torsional resonance in the cranks, and speed settings to be passed through as quickly as possible. I gather that some of the four row radials only had two usable RPM settings, due to resonance problems in the long crank shaft.

 

[Ed Norton]

Oh man my phone won't display the link therefore I have to look in the library. I look forward to that and will probably go later today.

 

[Anarchy]

Ed,
Do you get down to Phili?

The Science museum there had a late, American made radial, sectioned. This is going back 15 years, so it might all be fenced in now, but back then, I refrained from actually climbing on it, but I had a really good peer into it.

They also had a Guiberson, static radial two stroke diesel aero engine from the inter war period. It had a large single valve on each cylinder head, that served for both inlet and exhaust, harkening back to the days of the Gnome Monosoupape (single valve) rotary radial.

On the subject of rotary radials, I think Col Palin's guys are still flying rotary radials in America, and there were some guys in Kiwi land, who'd were building and flying full size rotaries as well.

Scaled down rotaries, especially the Bentley BR2 are very popular projects for home shop guys over here.

For anyone who's not familiar with the rotaries, they were lubricated with castor oil which passed through the engine and was blown out of the exhaust as a fine mist. Biggles' white scarf was to wipe that castor oil mist off his goggles. Constipation was never a problem for pilots of rotary engined planes.

 

[Ed Norton]

Oh I'd love to see that..last time I was in an aviation exhibit I talked my way into a 707 flight deck on static display. I pulled the reversers and stuff like a kid!

I have seen some rotaries in airshows and the challenges to flying them are immense due to the gyroscopic and torque effects. The old aces put that into good service in dog fights.

 

[Ed Norton]

Jets also use castor oil for lubrication. In the big pistons endurance wasn't a matter of gas ot was a matter of oil lol

 

[Anarchy]

In the big pistons endurance wasn't a matter of gas ot was a matter of oil lol

I know some guys who have 1970s and 1980s Rolls Royce cars. The RR v8 uses a pint of oil about every 150 to 200 miles, I'm not sure of the reason, whether it is going round the piston rings or down the valve guides - what ever it is, that's the way they were made.

It's easy to forget about engines that actually need topping up with oil daily or twice daily, even when they're new, and that car engines needed reconditioning every 30,000 miles, before present day oil additives and better matching of materials and surface finishes on moving parts.

Getting back to being slightly more on topic. When I used to have a microlight, even though the rotax two stroke would have happily used mogas, I used to pay the extra for avgas - because I knew what quality of fuel I was getting. Generally the two strokes didn't wear out, they'd break a crankshaft or the needle roller bearings in the small end would break, distributing rollers everywhere.

Like the guys in olden days, we always had a field selected. I only had a sudden silence once, that was very scary silence.

the challenges to flying them are immense due to the gyroscopic and torque effects. The old aces put that into good service in dog fights.

The ones that had an actual carburettor - or what passed for one, changing the throttle setting also screwed up the mixture, so the guys had to rely on the momentum of the engine to keep it turning over while they fiddled with the mixture and got it firing again.
The Gnome Monosoupape didn't have any mixture control or throttle, so the only way to control power was to blip the ignition on and off.
Add in, wings that gave little if any warning of a stall, only one person in the world who knew how to recover from a spin (and he didn't know that no one else knew), and narrow undercarriage, It's a wonder any of them survived, let alone flew so brilliantly.
Admittedly this one clipped the fence and broke it's undercarriage (it's "late production" built to Sopwith plans and with close involvement of old TOM Sopwith. It does use a rotary engine), but it is so easy to have a landing mishap with old planes.

 

[Ed Norton]

Back in the days aviation was really Darwinian in nature. I have an autobiography of an early airmail pilot who flew those lightly wing-loaded wirebraced open cockpit jobs. It goes without saying that gyroscopic instruments, even venturi driven ones weren't yet invented but there were no laws giving authority to the pilot in command* US 14 CFR 91.3. And therefore the post office determined when they flew. They way they handled IMC conditions was as follows: Lock the controls in a climb until hopefully making it on top if that failed and they got into an upset, usually a spiral dive, pull back and add rudder to induce a spin upon visual contact recover from the spin and try again! Icing was equally appalling...wait for buildup take a forced landing in a field break it off then resume.

The early airline pilots were just slightly better off as chronicled in Ernest Kellog Gann's legendary book 'Fate is The Hunter' then finally the transition to the new fangled jets from relatively docile pistons and turboprops caused many disasters. The aviation pioneers were immensely skilled and brave aviators and every single regulation therein is written in blood, even modern Airspace classification.

Lycomings and Continentals need to still have the oil looked after but they are babies lol.

Thanks for the clarification Recovery4me now it makes sense most of those high performance jets are straight turbojets and they don't have as efficient combustion and the noise is crazy. I do believe that military operations have become more friendly with respect to being good neighbors less use of afterburning, more restrictions on practice airspace and location of military operations areas etc and a long standing prohibition of supersonic flight over land. I am not a military guy at all but I have heard this stuff second hand from military pilots.


Edit:

* The Avigation Act of 1926

 

[Anarchy]

and a long standing prohibition of supersonic flight over land. I am not a military guy at all but I have heard this stuff second hand from military pilots.

There was a really big double boom over here a couple of years ago. I'm surprised how few people recognised what it was.

we get a lot of very low military flying, but normally the sonic booms are ones refracted from the upper atmosphere from guys over the north sea.

The early airline pilots were just slightly better off as chronicled in Ernest Kellog Gann's legendary book 'Fate is The Hunter' then finally the transition to the new fangled jets from relatively docile pistons and turboprops caused many disasters. The aviation pioneers were immensely skilled and brave aviators and every single regulation therein is written in blood, even modern Airspace classification.

They certainly weren't short of names for the roads on newly built cold war air bases!

I think it was the German glider pilots during the inter war years who worked out about wave and alto cumulus lenticularis. I used to love playing in gentle wave down wind of the pennine hills. The guy who taught me to fly a microlight had been up to 14,000 feet one evening in a 2 stroke powered microlight, without the wave, i think the ceiling, 2 up, is about 5,000 feet.