C150 vs C152
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The UK CAA stance on MoGAS in Cessna 150s and many other types is here
http://www.caa.co.uk/docs/33/AN98.pdf
and here
http://www.caa.co.uk/docs/33/AN98A.pdf
from which, under certain conditions you CAN use MOGAS in a Cessna 150 in the UK
BEX
http://www.caa.co.uk/docs/33/AN98.pdf
and here
http://www.caa.co.uk/docs/33/AN98A.pdf
from which, under certain conditions you CAN use MOGAS in a Cessna 150 in the UK
BEX
Moderator
Bilhar,
There are no adjustments to the O-200 to operate on Mogas, though be cautioned that the configuration of the engine and fuel system can affect the interchangeability of Mogas and Avags use. In particular, "O" rings and other seals, including in particular, the plunger of the fuel strainer, may be affected by the Mogas (they could swell up). Also, some carburettors have a foam float, others a metel float. You'd rather have the metal, as the Mogas will not attack the metal, and it may the foam.
There are other considerations with Mogas use. Read and understand them. Transport Canada has an excellent document #TP10737 on the subject (I contributed to it). Once you have a good understanding, it is an excellent fuel for 150's. And the icing on the cake is that in Ontario, Canada, I get the road tax imposed upon the Mogas refunded to me, as I did not use the gas on the road!
Pilot DAR
There are no adjustments to the O-200 to operate on Mogas, though be cautioned that the configuration of the engine and fuel system can affect the interchangeability of Mogas and Avags use. In particular, "O" rings and other seals, including in particular, the plunger of the fuel strainer, may be affected by the Mogas (they could swell up). Also, some carburettors have a foam float, others a metel float. You'd rather have the metal, as the Mogas will not attack the metal, and it may the foam.
There are other considerations with Mogas use. Read and understand them. Transport Canada has an excellent document #TP10737 on the subject (I contributed to it). Once you have a good understanding, it is an excellent fuel for 150's. And the icing on the cake is that in Ontario, Canada, I get the road tax imposed upon the Mogas refunded to me, as I did not use the gas on the road!
Pilot DAR
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I knew it to good to be true we allowed to use mogas conforming to bs4040 in uk
ie 4 star leaded petrol but its sold in very few outlet at price same as avagas 1.59per litre in herts
ie 4 star leaded petrol but its sold in very few outlet at price same as avagas 1.59per litre in herts
bilhar, it will have 4 times LESS lead than 100 LL so will reduce any plug fouling problems you may encounter when using 100LL in a Continental A-65 or it's siblings. Bit of a problem carting it around in 5l containers though......
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I have no knowledge of the UK requirements for operation of an aircraft on Mogas. I can say that technically, leaded or high "octane" gasoline is not requirement for the O-200, and many other low (7:1) compression engines. The absence of alcohol is important though. The O-200 will happily run on automotive gasoline (free of alcohol) of the lowest "octane" rating available. The test methods for octane in Avgas, and "octane" in Mogas vary slightly, but are close, particularly for normally aspirated engines. Thus the fact that the O-200 was born to run 80/87 (note 80) means it does not require the "octane" rating of even the lowest automotive gasoline, which is generally around 87. The purests here will be able to offer more detailed comments, but that's the general idea.
If regular automotive gasoline (free of alcohol) is not approved for use in appropriate aircraft in the UK, someone should be considering that. The downside however, may be that regular automotive gasolines contain alcohol in the UK (I don't know). These gasolines would work (we flew a 150 with a slightly modified O-200 on pure ethanol for two years) but there are changes to be made. Still a good idea though...
Pilot DAR
If regular automotive gasoline (free of alcohol) is not approved for use in appropriate aircraft in the UK, someone should be considering that. The downside however, may be that regular automotive gasolines contain alcohol in the UK (I don't know). These gasolines would work (we flew a 150 with a slightly modified O-200 on pure ethanol for two years) but there are changes to be made. Still a good idea though...
Pilot DAR
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Ahem, there's more form the CAA about the use of unleaded MogAS here
http://www.caa.co.uk/docs/33/AN98C.pdf
and a very good saftey sense leaflet here
http://www.caa.co.uk/docs/33/ga_srg_07webSSL04.pdf
BEX
http://www.caa.co.uk/docs/33/AN98C.pdf
and a very good saftey sense leaflet here
http://www.caa.co.uk/docs/33/ga_srg_07webSSL04.pdf
BEX
Re reduced power takeoff.
When teaching for the Cpl I always did a reduced power takeoff as a dual exercise. The purpose was to expose the student to how the airplane would feel and what the performance would look like when attempting a high density altitude takeoff. It was also valuable for reinforcing the importance to fly the airplane on speed and perfectly coordinated. The difference between a few knots too fast and the ball 3/4 out of the cage can be as much as a 50 % reduction in climb rate for a low powered airplane and high DA.
I also used the "make the airspeed indicator go to zero" exercise (in the C150/C172) part of my slow flight training. I was amazed at how many students had never been slower than 55 kts and how they thought they were going to die if the stall warning horn came on on flight. Concentrating on what the aircraft felt like at low speeds was a good confidence builder and emphasized the point the airpalne should always be doing what you want it to be doing at any given part of the flight.
When teaching for the Cpl I always did a reduced power takeoff as a dual exercise. The purpose was to expose the student to how the airplane would feel and what the performance would look like when attempting a high density altitude takeoff. It was also valuable for reinforcing the importance to fly the airplane on speed and perfectly coordinated. The difference between a few knots too fast and the ball 3/4 out of the cage can be as much as a 50 % reduction in climb rate for a low powered airplane and high DA.
I also used the "make the airspeed indicator go to zero" exercise (in the C150/C172) part of my slow flight training. I was amazed at how many students had never been slower than 55 kts and how they thought they were going to die if the stall warning horn came on on flight. Concentrating on what the aircraft felt like at low speeds was a good confidence builder and emphasized the point the airpalne should always be doing what you want it to be doing at any given part of the flight.
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Concentrating on what the aircraft felt like at low speeds was a good confidence builder and emphasized the point the airpalne should always be doing what you want it to be doing at any given part of the flight.
Moderator
Yes, the airspeed indicating zero in an airborne C150 was I problem I encountered during the initial flying in my recently purchased STOL C150 21 years ago. Whenever I flew in the STOL speed range, the airspeed information was not useful. Shortly thereafter, I purchased a Bell 206 helicopter airspeed indicator, and marked it appropriately for Cessna 150 speeds. As that airspeed indicator will indicate reasonably down to 10 MPH, it does the job. There is a little position error at the high angles of attack, but by flying in dead still air, and comparing the GPS, it's only 1MPH or so. My lowest indicated airspeed during level flight was 21 MPH, with 25 MPH being easily attainable. You don't want to spend too long there though, as the engine gets warm! Bear in mind though, takeoff, approach and landing are not possible at such speeds though, becasue the angle of attack is such that you strike the tail before the mainwheels touch or leave the runway as the case may be (ask me how I know).
As an aside, I used to fly a late model Robertson STOL Cessna 185 on Wipline ampibious floats. The Robertson Flight Manual Supplement for that aircraft instructed that a runway takeoff be rotated at 32kts IAS. the factory airspeed indicator is just quivering at that speed, but the plane would fly. This was possible because the angle formed between the main wheels and the transomes of the floats was large enough to permit the high angles of attack on the ground to really get the STOL kit doing what it should be.
The use of alcohol in aircraft has considerations in addition to operating compatability, those are fuel flow and flight manual information. The lower energy density of the alcohol results in the possible need for changing the jet size in the carb to permit increased fuel flow. If there is a greater fuel flow, the preformance information (range) in the flight manual is no longer valid. The problem is that depending upon the mixture of gasoline and alcohol in the system the fuel flow varies considerably. The Pure enthanol C150 I used to fly had a fuel flow at takeoff of 11 to 13 GPH, at takeoff, and 9 or so in cruise. When run on pure gas, it was more like 7 to 9 on takeoff, and 5 GPH in cruise. When taking off on pure gasoline, you'd have to have the mixture about half way out, or the engine would flood, and quit. These variabilities made the aircraft very operator technique sensative, and thus not eligible for STC approval.
Enthanol works, but there's more to it than meets the eye.
Pilot DAR
As an aside, I used to fly a late model Robertson STOL Cessna 185 on Wipline ampibious floats. The Robertson Flight Manual Supplement for that aircraft instructed that a runway takeoff be rotated at 32kts IAS. the factory airspeed indicator is just quivering at that speed, but the plane would fly. This was possible because the angle formed between the main wheels and the transomes of the floats was large enough to permit the high angles of attack on the ground to really get the STOL kit doing what it should be.
The use of alcohol in aircraft has considerations in addition to operating compatability, those are fuel flow and flight manual information. The lower energy density of the alcohol results in the possible need for changing the jet size in the carb to permit increased fuel flow. If there is a greater fuel flow, the preformance information (range) in the flight manual is no longer valid. The problem is that depending upon the mixture of gasoline and alcohol in the system the fuel flow varies considerably. The Pure enthanol C150 I used to fly had a fuel flow at takeoff of 11 to 13 GPH, at takeoff, and 9 or so in cruise. When run on pure gas, it was more like 7 to 9 on takeoff, and 5 GPH in cruise. When taking off on pure gasoline, you'd have to have the mixture about half way out, or the engine would flood, and quit. These variabilities made the aircraft very operator technique sensative, and thus not eligible for STC approval.
Enthanol works, but there's more to it than meets the eye.
Pilot DAR
Moderator
Sorry Roger,
Those aren't drawbacks, they're benefits! And there are many. If you're running an O-200 on 100LL, leaning at all altitudes is very important. Lead builds up on the plugs and exhasut valves if not leaned properly, and although you may not pay the bills, if you stick a valve, or foul some plugs, you may be wishing you'd leaned. It runs poorly on three cylinders.
Mogas use was very much promoted by Ceasar Gonzales, a former senior engineer at Cessna, whose personal 150 kept fouling plugs on 100LL. He told me that he force landed twice because of a loss of power. He has written an excellent book on the subject.
Pilot DAR
and with the drawbacks of using mogas I don't really see the point!
Mogas use was very much promoted by Ceasar Gonzales, a former senior engineer at Cessna, whose personal 150 kept fouling plugs on 100LL. He told me that he force landed twice because of a loss of power. He has written an excellent book on the subject.
Pilot DAR
Moderator
No drawbacks! At present in Ontario, Mogas is just about one half the price of Avgas, so you're (I'm, anyway) saving 50% right there. On top of that I get $.12 road tax refunded to me. No drawback in saving $.
There is no less power in Mogas, inless it is mixed with alcohol. Indeed Canadian spec Mogas is equal to or as much as 2% more engergy dense than Avgas (that means that for the same weight of fuel you go a little farther).
Mogas has a slightly greater propensity to allow the formation of carb ice, which I can see being an issue more in the UK, but I really have not found to be a problem at all here. Good carb heat management will prevent this being a problem.
Avgas has some horrible drawbacks in O-200's and other low compression engines as I have previoulsy mentioned. Mogas is good for the O-200.
After more than 3000 hours of flying on Mogas, I could not be more pleased to use it as an aviation fuel, in appropriate aircraft - The standard Cessna 150 is ideal. No drawbacks!
Cheers, Pilot DAR
There is no less power in Mogas, inless it is mixed with alcohol. Indeed Canadian spec Mogas is equal to or as much as 2% more engergy dense than Avgas (that means that for the same weight of fuel you go a little farther).
Mogas has a slightly greater propensity to allow the formation of carb ice, which I can see being an issue more in the UK, but I really have not found to be a problem at all here. Good carb heat management will prevent this being a problem.
Avgas has some horrible drawbacks in O-200's and other low compression engines as I have previoulsy mentioned. Mogas is good for the O-200.
After more than 3000 hours of flying on Mogas, I could not be more pleased to use it as an aviation fuel, in appropriate aircraft - The standard Cessna 150 is ideal. No drawbacks!
Cheers, Pilot DAR
