skippydiesel

Recent trip to The Oaks - Condobolin, NSW, saw 1C, for 90 minutes, at 4500ft. Felt like my feet & calves were about to drop off as I dismounted on arrival.

As a result of the above experince, have been thinking on workable solutions for our short but sometimes uncomfortably cold winter flying months;

Plumb in the traditional hot air from silencer/exhaust system.

• Well tested, effective aircraft cockpit heating solution BUT will require considerable fabrication, increased risk of CO poisoning  & I suspect cockpit noise levels. Will add little/nothing for 10 months of the year.

Make up an automotive style coolant heater with small fan to circulate.

• Doable but as with above a fair bit of work involved taking the bird out of operation during some of our best flying conditions.  Additional weight (got to add at least 3-5 kg). There may also be engine overcooling issues and due to long coolant hoses, additional joins  = heightened failure risk.

High Top Ugg Boots

•  Yeah but will require changing to regular shoes for any serious ground activities (long walk to point Percy, etc). Bulky when not in use (aircraft space challenged) No longer as cheap as in my youth (last time I had a pair) $70 - $320

Heated socks that have been developed for winter activates such as skiing.

• This has real potential. No aircraft mods required.  Battery powered. Some rechargeable.  Claims of adjustable temperature from about 38C upwards (seems a tad hot to me). Relativly low cost (from low $ teens to about $450, with most under $100). Light weight and low volume. This might just be the way to go for our short winter.

I am keen to hear from anyone who has experince using heated socks.😈

9 hours ago, skippydiesel said:

29/06/25 Todays Fun

 

Departing The Oaks -Landing  Condobolin  Arrive about 10:30-11:00

 

Condobolin - Landing Cowra Arrive about 12:00 -12:30

 

Cowra - The Oaks Landing Mid afternoon?

Round trip 4.3hrs (Hobbs).

Times worked out very well - got to Cowra  before 12:00

Was almost frozen stiff by the time I got to Condo. Great air, lots of ground fog. Condo deserted - if it wasn't for a passing cattle truck, I would have thought mankind had evaporated.

Cowra, Not quite as quiet. Lots of training aircraft lined up waiting for the week to start. Met a wonderful couple, who gave me a lift into town & back for some fuel. 

Cowra to The Oaks via Wingello - Cloud at 6/8th  5000ft.. Went over the top at 7500Ft - smooth as!

This was my longest flight in the Sonex - Perth soon😈

29/06/25 Todays Fun

Departing The Oaks -Landing  Condobolin  Arrive about 10:30-11:00

Condobolin - Landing Cowra Arrive about 12:00 -12:30

Cowra - The Oaks Landing Mid afternoon?

On 27/06/2025 at 6:30 PM, BrendAn said:

 

Just back from a very nice 2 hr jaunt  - The Oak to a friends place between Yass & Canberra (did not land). Could see forever.  Not quite silky smooth but almost. 3C at 5500ft. Averaged 14.5L/hr @ 130 knots true.  Lake George was an amazing metallic purple. Great to be alive!😈

18 minutes ago, BrendAn said:

No thanks. Don't want an extra fuel line running up to the motor.  Or around the cockpit.

Thats fine BrendAn - FYL; A return line does not have to run from/to the engine. Usually T'd in somewhere between the pump & the carburettor(s). 😈

4 hours ago, BrendAn said:

2 strokes don't use the vapour lock return system because they are not affected by vapour. Good suggestion but fitting the correct pump is the way to go. Thruster has supplied the facet model number so it will be an easy job.

The vapour lock was only an added bonus (not for you) - Save your $$ and put in a return line with  a Mikuni No 35 or smaller restrictor jet.😈

5 hours ago, BrendAn said:

 

Skippy is implying that you need the pump on to get full power at critical phases of flight. 

 

 

 

Nooooo! Way out of context.

The electric Boost/Aux/Back Up/Secondary (whatever name you wish) is ON as a precaution should the Main/Mechanical fail, in whole or part at a critical time in flight ie TO/Climb-Out/Low level opps. Of course it will also be used should the mechanical fail at other times. I have never ever suggested otherwise😈

"My latest xair has a 618 and if I leave the electric pump on too long at idle it overcomes the the needles and starts flooding.  Will have to swap for a lower pressure pump or fit a regulator."

It may be simpler/less costly to fit a fuel return line (added benefit - will help to remove vaporised fuel). If already fitted - try a larger restrictor jet.😈

I may be mistaken but didnt Rover have a turbine powered car and weren't some tanks similarly powered ??😈

7 hours ago, Underwood said:

Having moved my Oil cooler to a position that allows its own air intake instead of piggybacked behind the Coolant radiator, I now have the opposite problem of over cooling the oil.

cant get max above 80c so will have to blank some of the oil cooler probably use neoprene wrap...not a problem

But allong with the low max temps its also taking ages to reach temp before flying so I'm gonna fit a thermostat. (thermostasis unit)

Was just wondering do any of you guys fit them?, or are your ambient temps high enough that warm up is hardly ever a concern?

I have one, never used - came with the aircraft.

I can only sympathise with those that must endure long cold winters - living near Sydney, Australia, I enjoy a more moderate environment. I still "blank" off part of my coolant radiator & oil cooler when day temperatures routinely go below 25C.

After much trial/error I arrived at a good compromise blanking, which I have photographed for future reference. In Cruise I have Oil temp. 90-95C. Coolant/CHT 90C. Climb OUT 100-105C.

I find that the engine warm up period (Oil -50C) is well spent on checks, review of plan, etc

I use  adhesive backed refrigeration aluminium tape. Easy to cut & apply -  can leave a residue when removed. Residue responds to most hydrocarbons.

Reasons for use -

• Engine operated in seasonally very cold climates  eg. N. America, UK, N Europe etc
• Speeds warm up. Reduced fuel consumption & frustration. Certainly important in cold climate opps but more of a perception benefit, in warmer climates
• May maintain even engine temperatures on descent - assist with carburettor ice prevention (if fitted) 

Reasons against - 

• Significant added complexity = more to go wrong = heightened risk. From memory, at lest 4 additional joins in oil supply hose. All things mechanical will fail.
• Increased weight. Probably a minor concern however every minor increase adds up.
• Cost. Depending on arm length & depth of pockets, may or may not be an issue.😈

3 hours ago, turboplanner said:

Electric fuel pumps on Basic (training) GA airctraft were introduced as an extra safety feature in the case of a mechanical fuel pump failure near the ground.

The Check list was:

Pre Start:                                                  Fuel pump on, check making pressure.

After Start:                                                Fuel pump off

Pre Take Off:                                            Fuel pump on, check pressure

1000 feet:                                                 Fuel pump off

Pre-Landing checks (downwind leg):    Fuel Pump On

After landing:                                           Fuel Pump Off 

 

The reason for turning off after engine start and in flight was to avoid the situation where a fuel line might be cracked, or blow off at a connection and cause a runaway situation spraying fuel in the engine compartment until there's a fire or the smell makes you turn it off and hope.

 

The pumps were not designed as "boost" pumps. They were simply a redundancy item like twin spark plugs and twin magnetos.

The carburettors determined how much fuel they wanted to draw.

 

RA Airctraft, including self built are likely to have anything in their system, and in some cases producing less efficiency than the kit designer specified. Speculative negativity, without foundation

 

RA "Boost" Pumps

This implies a pump that boosts the pressure. Some do - mine by about .5psi

If it really is a boost pump, and not just an incorrect name, this implies that a mechanical pump is fitted, but doesn't have enough capacity to supply fuel to the engine at full power. In this case if you don't have your boost pump working you could run the engine lean and  get combustion chamber damage. (I suspect that people here are just mis-calling the name of the pump, but you never know.) Agreed - see below.

 

 

Some comments on your statements above;

NOTE: My comments are with reference to Rotax naturally aspirated (carburetted) engines. Fuel injection is a whole diffrent ball game.

3 hours ago, turboplanner said:

 

The term "Boost Pump" is as you say a misnomer - Back Up/ or Auxiliary Pump  would be more a acurate description of the function.

 

My usage (slightly diffrent to yours) & reasoning;

• Pre Engine Start - Boost Pump ON - observe pressure rise  - OFF. Reason for off, is that there is no further benefit to the starting regime (unless vapour lock suspected). Fuel system has been primed and there is no good reason to add the small additional electrical load when demanding a high starting load.
• Pre Take -Off - Boost Pump ON - observe any changes to fuel pressure.
• At or about Circuit Hight  - Boost Pump OFF (when convenient to do so. There is no reason for hast)
• Pre Landing (including any low level opps) - Boost Pump ON
• Post Landing - Boost Pump OFF (when convenient to do so)

While it is possible to run the Boost Pump continually (some do) there is no benefit in this practise. There are two potential disadvantaged in continual use - shorten the pumps service life and may hide a deterioration in the performance of the Primary mechanical pump. 

The Boost Pumps primary purpose is to ensure fuel supply to the carburettors at times of potential or actual high engine power demand, when a loss of power may result in crash. Its secondary function is to prime the fuel supply system to ensure a "good" engine start. The latter may include hot starts where vapour lock is a potential or suspected 😈

3 hours ago, turboplanner said:

 

5 hours ago, Thruster88 said:

Regarding your posts that the carburetor engine still receives adequate flow even at low fuel pressure, I TOTALLY AGREE, however to say the fuel pressure gauge is in error sometimes makes no sense. How can it be in error sometimes?  I don't recall using the word "sometimes" in this context. Have checked back on posts  - nope!

 

Is your fuel pressure on the ground, Boost pump only the same as while flying, engine pump only? Boost pump only, on the ground, about 5 psi - in Air, mechanical pump only, 4.5 psi. Mechanical + Boost delivers about 5.5 psi

 

In a tecnam /912 I have been flying lately they are the same. Turning off the boost pump in flight results in zero change in fuel pressure on the mechanical fuel pressure gauge. Below is a 912 fuel pump. A blockage in the vent line might explain your pressure rising over a minute or two. The little spring controls fuel pressure and should immediately take over from the boost pump unless perhaps the diaphragm is being held down and not able to stroke.

There is no blockage - I have tried to "fix" this anomaly over the last 18 months to no avail. As there has never been even a hint of engine hesitation, I will just live with it. 

In about 3 years (5 year scheduled replacement) I will replace the mechanical pump - it will be interesting to see if the new pump delivers the same/diffrent performance/characteristics.😈

 

 

 

2 hours ago, Thruster88 said:

How would the fuel pressure gauge know that you had just turned the boost pump off and then decide to indicate a lower pressure for 1 to 2 minutes? It must be a very clever or mischievous one, or it might just be showing what is actually happening. 

Nope - no effect on engine performance ie engine still receiving a sufficient fuel - remember pressure , in this context, is a secondary indicator of supply  - the engine runs on volume not pressure..

It can only be an anomaly of my fuel distribution system or some inherent fault in the pressure sensing.

IF the pressure is actually dropping , as indicated, the engine is somehow still receiving sufficient volume of fuel to keep functioning normally.😈

So northerly direction from Canberra - how does that fit the prevailing winter wind direction?

I guess it will depend on the prevalence/location of the low/high pressure systems at that time and luck😈.

Hi AntekinCanberra,

I have fantasised about such a trip for years.

Not sure from your post, if you are looking for Pax and / or other aircraft to join your safari??? I have my own aircraft, so would be "flying in company".

From where and when do you plan on departing?

Do you plan a clockwise/anti clockwise rout ?😈

2 minutes ago, BrendAn said:

what is the idea behind them.  do they work like turned up wing tips.

I guess that the theory. 

I remember, some many years back, that this was flagged as the next propeller performance innovation. As we all know, doesn't seem to have eventuated. I wonder why?😈

Sonex Legacy/Rotax 912 ULS - Boost pump on for Take-Off and all low level opps. Turn off Boost when at/above Circuit height - immediate drop in fuel pressure. Pressure return/recovers slowly over about 1- 2 minutes. Never been any change in engine note, so am of opinion that gauge is likly in error.😈

29 minutes ago, danny_galaga said:

Yes, I do know that. Hence I was just joking about it. You see, calling it a built in prop strike negates it being a prop strike and thus.... nevermind. The moments passed.

The jokes on me then - I didnt realy think it was a deliberate change to the tip.😈

Naa - Not a strike - aerodynamic enhancement 😈

SPY!!!!😈

9 minutes ago, red750 said:

Resurecting this old thread - there are a number similar.

 

I came across this image, and know what it is, but thought I'd see who else knew.

 

 

 

 

 

 

A "Terriblia  Confused"  - will consult with psychiatrist to determine gender😈

32 minutes ago, spacesailor said:

Many thanks " skippydiesel " .

No idea when my granddaughter will ever get enough time from her nursing job .

She seems to be working long hours everyday of the week.

Saving for her first house .

spacesailor

 

Not going anywhere within foreseeable future but do have tentative plans to visit Perth, when weather window opens and the Gods smile upon me.😈

On 11/11/2023 at 8:37 PM, spacesailor said:

Now November 

Not a whisper. 

spacesailor

Hi Spacesailor. Didnt see this post, sorry.

If Granddaughter still looking for a TIF, I may be able to help. I am based at The Oaks International (just up the road from Camden) Only one little problem - my Sonex is weight challenged, so passenger must be of slight build and I need advanced warning so as to be sure fuel load also suitable.

Had a terrific short fly this afternoon - perfect weather, visibility unlimited, smooth as silk at 5500 ft😈

On 18/06/2025 at 2:50 PM, Blueadventures said:

I use the Bendix brake grease product, blue colour and also put a smear between caliper piston and back plate of brake pad to reduce squeaking.

Good for you. So a lubricant actually designed for this purpose - not something someone found on the workshop shelf that they thought might just do the job.😈

4 hours ago, BrendAn said:

Is that like when you sent me a DM advising me not to offer McKay heater hose to people then a couple of months later you were saying McKay hose was good quality 

?????????????????

NOTE: I have NO experience with MCKay hoses. I have found that they offer an astonishing range, which may be of benefit to someone wishing to try them - end of story.😈