Fuel management and muffler problems - split

[frank marriott]

Last Friday my eldest daughter was to fly Tiger from Sydney to Coffs but due to a problem at BNE Airport (emirates 380) with crap on the runway Tiger had an issue where the plane for her flight was delayed and the tiger approach to something like this is to just completely cancel a flight segment and all of a sudden your no longer late, coffs was the sacrificial lamb that day......She blew her stack with them and told them to stick it.....they had the last laugh at my expense, I'd paid for the return ticket.....3 weeks for a refund......Anyway Saturday morning sees me take off from South Grafton and on the way to Maitland to pick her up and bring her home.....she can catch the train back!

 

Only about 5hrs since the 3300 was overhauled.....I immediately started a climb so as to safely go round tiger country west of Coffs (very unfriendly territory)...anyway at about 3500ft motor missed, picked back up and then stopped altogether.......I'd forgotten to turn the fuel taps on on the side pillars and ran out the header tank....... I've since determined I need to make up a placard, laminated it and add Velcro to the dash so that I cant possibly fly and forget...something I swore Id never do...... I can report that my pucker ring tension was tested multiple times and found to be within spec.....once the taps were turned on the header filled faster than my heart rate slowed to normal......

 

Beautiful smooth flight down, about 2hrs 10 minutes roughly as I had to use the closest section of the lane of entry for Maitland (that within the 25nm Willy town ring)... going home 1 hr after landing was turbulent and all of a sudden the see for miles was replaced with haze..... I have to say that if Sat morning is normal for Maitland on a shared CTAF frequency trying to get a Tx in was murder......and Meatbombers all over the place I had to detour multiple times to avoid conflict over Taree and then where I intended to go west of maitland at Elderslie to avoid having to use the lane of entry with its low ceiling and then again at Maitland, where meatbombing is clearly a big and successful business!

 

On the way back I thought that the engine sounded louder......when I landed I had a look and saw that Id lost some springs that hold the muffler to the header pipes and the remaining ones had stretched to the point that the headers had completely disengaged from the muffler..... Really lucky that I had as part of the overhaul added 6CHT and 6EGT gauges which meant that the grommet through the firewall into the cabin was stuffed to capacity....no CO, or at least none that we could detect (the other combustion products that is) where as if I had left it with the default 2 egt and 2 cht there may very well have been another thing to go wrong as the cheese holes all strived to align...

 

So.. 2 things happened that could have impacted the 4.5hrs of flight....one was clearly my fault and I intend to ensure it doesn't happen again, and the 2nd just bad luck I think

 

Andy

Andy

Have you any opinion on how the springs could have come undone e.g. too long/ loose , or do you have some other reason in mind?

 

Note: Topic originated in a different thread - Mod xox

 

 

[Guest Andys@coffs]

AndyHave you any opinion on how the springs could have come undone e.g. too long/ loose , or do you have some other reason in mind?

Frank

 

Not sure. Ive ordered a new set and will pull the bottom cowl off this weekend to try and understand why. Spoke to Keith Rule and he's aware of the springs breaking but not stretching.... Yet thats what i saw..... I'll put in a condition report to raaus with photo's.... I was worried about too much heat yet egt's were all well below 700c so dont know why they stretched

 

Andy

 

 

[frank marriott]

Andy

 

I have seen, on a Rotax actually which was subjected to higher vibration, lock wire through the springs and securing points. The lock wire was not tight but only to stop excessive movement should a spring fail. It seemed like a good and simple idea to me. I change mine regularly, when rusting has just started, but after a major service I presume yours would have been new anyway.

 

 

[facthunter]

Andy, the stretched ones may have gotten hot and softened when the exhaust gases were impinging on them. Those spring problems are common on 582's. Some goopy black stuff stops them vibrating and a wire loop stops them flying off into the prop. If you engine makes different to normal sounds you should investigate it, ASAP. An old rule but a good one. Nev

 

 

[Guest Andys@coffs]

Andy, the stretched ones may have gotten hot and softened when the exhaust gases were impinging on them. Those spring problems are common on 582's. Some goopy black stuff stops them vibrating and a wire loop stops them flying off into the prop. If you engine makes different to normal sounds you should investigate it, ASAP. An old rule but a good one. Nev

Nev

 

Thanks for that hint, I suspect your right about the gases softening them, it makes sense and something I will look for on the weekend. I had seem the silicon on the springs on my 582 trike and also the lockwire through the middle and around the outside to stop breaking springs making a mess of your prop on a trike (pusher)... but neither the silicon or the safety wire was on the springs. Keith Rule suggested that I might have lost a spring or 2 due breakage, and then that might have allowed gasses as Nev suggests to soften the remaining ones....

 

Biggles, thanks for the hint....I need the pillar fuel taps because when tanks are full I need to transition the aircraft 180 degrees as I get it out of the hangar and that means I'm in a one wing down scenario while I turn the aircraft. without the taps closed the high tank just flows downhill to the low wing and then overboard...... As you say I got distracted as 2 trikes arrived and parked in such away to make it difficult for me to get out..... A minor thing that interrupted my normal routine. I was lucky that I had been climbing the whole time and had alt to play with.....remembering what was wrong and fixing it took only the time it took me to do a quick 180 back to friendlier ground but had it happened at Maitland where the lane of entry to the north is alt limited to 1600ft and there is ground at points close to 1000ft then I may not have had the time to be mucking about trying to work out what was wrong and fly the plane...... Its easy to think the whole HF thing is a pain...but I think all of us at one stage or another will be put in a position where you cans see first hand exactly what they are talking about. I guess the other thing is the size of the header tank....it needs to be small enough that you cant get off the ground if the taps are turned off, or big enough that you can have some height (assuming you climb after take off to safe height) to turn into time as you work the issue through.......I was climbing conservatively (new engine being kind to it cooling wise) and was at about 4000ft above ground when the motor first surged... lost about 600ft when I was again settled down to the direction I was wanting to go and recommenced climb to the eventual 8500ft to go to the west of Coffs

 

It may, in time, be as wise as the HF training, that we cover the L1 stuff....what ever that turns out to be.....

 

Andy

 

 

[facthunter]

This might sound a bit pedantic Andy but when changing fuel tank selectors I like to leave it till I am over someplace I can land IF I'm not absolutely familiar with a particular plane and have previously proven the system. Also IF you change a tank and the engine decides to play up a minute or so later restore the previous selection. This of course won't work IF you have run the previous tank completely dry. I don't usually do that as I prefer to take off and land with both tanks ON. Nev

 

 

[Guest Andys@coffs]

Speaking from my own personal experience here....fuel management isn't something that was covered at all in my training. It was covered in planning obviously, but not during flight. That said I learnt to fly on a trike which has one fuel tank and a fuel tap that as pilot you cant get to in the air so inflight management involved looking at time spent with the motor on and nothing else.

 

The J160 that I did my 10hr conversion from flexwing to fixed wing only had a single fuel tap so again was pretty much the same as the trike. My J230 has 3 taps, a common one near pilots leg and one on each pillar for each wing. As others have said, newer 230's don't have them. My fuel gauges are simply sight tubes that rock around in turbulence and its pretty difficult to take a meaningful measurement from them except in Hollywood weather..... Common advice with the J230 is to fly balanced otherwise fuel will feed from one wing more than the other (or more accurately will transfer from one wing to the other via the connecting line between the 2 wings......I have not seen any advice that says in a J230 you should fly 15 minute segments on 1 wing then the other etc etc when going long distance xcountry..

 

So I wonder if my training was simply deficient, compared to say GA......I don't know what I don't know

 

Andy

 

 

[biggles]

Speaking from my own personal experience here....fuel management isn't something that was covered at all in my training. It was covered in planning obviously, but not during flight. That said I learnt to fly on a trike which has one fuel tank and a fuel tap that as pilot you cant get to in the air so inflight management involved looking at time spent with the motor on and nothing else.The J160 that I did my 10hr conversion from flexwing to fixed wing only had a single fuel tap so again was pretty much the same as the trike. My J230 has 3 taps, a common one near pilots leg and one on each pillar for each wing. As others have said, newer 230's don't have them. My fuel gauges are simply sight tubes that rock around in turbulence and its pretty difficult to take a meaningful measurement from them except in Hollywood weather..... Common advice with the J230 is to fly balanced otherwise fuel will feed from one wing more than the other (or more accurately will transfer from one wing to the other via the connecting line between the 2 wings......I have not seen any advice that says in a J230 you should fly 15 minute segments on 1 wing then the other etc etc when going long distance xcountry..

 

So I wonder if my training was simply deficient, compared to say GA......I don't know what I don't know

 

Andy

Yes , try to stay in balance at all times with ALL fuel taps fully open . One less thing to worry about if something else happens to grab your attention . Most Jabs seem to drain tanks unevenly .

 

Bob

 

 

[Old Koreelah]

Yes , try to stay in balance at all times with ALL fuel taps fully open . One less thing to worry about if something else happens to grab your attention . Most Jabs seem to drain tanks unevenly .Bob

Useful discussion, fellas. Alternating between tanks every fifteen minutes seems a bit extreme. Every thirty (after burning 7 or 8 litres) would suit me. Would it not be more prudent to fly with one tank turned off? In case of fuel leaks, at least you have that tank to fall back on if the noise stops.

 

 

[Admin]

Useful discussion, fellas. Alternating between tanks every fifteen minutes seems a bit extreme. Every thirty (after burning 7 or 8 litres) would suit me. Would it not be more prudent to fly with one tank turned off? In case of fuel leaks, at least you have that tank to fall back on if the noise stops.

Balance could be an issue

 

 

[frank marriott]

A simple method with switchable tanks [& low wing such as the SE Piper range] is to fly for the first half hour on one tank and then switch every hour after that - at any given time the max out of balance will be 30mins.

 

For the J230, with all on, if you get out of balance just push the rudder and fly half a ball out of balance and it flows across quite quickly. Mine only has the on/off switch but simple to keep fuel balanced - or trim for a heavy Pax.

 

 

[facthunter]

I wouldn't think swapping tanks every 15 minutes is required or recommended. Plenty of aircraft use fuel unevenly especially the "smaller" ones with 2 tanks selected all the time. If I was close to empty (less than 1/4) as a general rule, I would rather have 2 tanks selected at critical times. Having a 40 minutes "gascolator" seems a good scheme where you can see what's in it. I feel a bit more time might be given to fuel management. It often comes up for discussion actually the only times you know exactly how much fuel is there is when you fill it to the brim, or have it empty of useable fuel, or add or subtract a measured amount where appropriate , from the above starting points, or use a proven DIP system, accounting for out of level.. Gauges don't count alone. Even the best engines won't run without fuel. Nev

 

 

[metalman]

My plane will run the left hand tank right down before starting on the other side, it has both feeding into a collector with an on/off tap , the first time I watched the tank run down till I couldn't see the fuel sloshing (it has a window to see the fuel) I was very interested in what was under me in case. It hasn't failed and it's pretty common for the type ,I've still toyed with fitting taps to each tank, but it's more the thought of relying on the fuel to do its own thing rather than controlling it,

 

Matty

 

 

[rankamateur]

Balance could be an issue

Don't know about that, JG3 only has an extended tank in one wing of his savannah so that would be a 36 L imbalance if it mattered, beats carrying around an extra tank without sufficient MTOW to fully utilise it when carrying a passenger I guess.

 

 

[Dafydd Llewellyn]

If your fuel system has wing tanks and any way they can be both on at once, fuel cross-flow will be a problem, unless:

 

(1) The tank vents are crossed over - i.e. the left tank vent is on the right wing, outboard of (higher than) the outboard end of the right tank, and vice-versa; AND

 

(2) There is a tank ullage space vent line that goes from the high outboard corner of one tank to the high outboard corner of the opposite tank, and the bore of that line is larger than the bore of the vent lines. This ullage space interconnection line has been mandatory in FAR 23.975a(4) since about1975, but I suspect it is one of the things that has been left out of the "simplified" standards for recreational aircraft. It was introduced after a number of accidents where a loose fuel cap on a Cessna allowed all the fuel to be sucked out of the system; it's especially bad when the aircraft has rubber-bag tanks.

 

The problem with this sort of system is that there is a low point in each of the vent lines where it runs through the fuselage - so it is necessary to have a drainage provision for each vent line, separately. The fuel system gets complicated. It is also desirable to have a collector tank; you can prevent the collector tank from emptying itself to the wing tank in a sideslip by crossing over the feed lines to the collector tank. You do not normally find this level of detail design in recreational aircraft, unfortunately.

 

The problem of people taking off with the fuel turned off can be largely overcome by an arrangement whereby the fuel must be "on" before you can access the starter. There's at least one type that has this feature.

 

These problems have been around for about a century; there is really no excuse for lousy designs in fuel systems - but one sees it all the time.

 

 

[Downunder]

I really think each tank should have it's own tap/valve. Pilots have more important things to think about than flying out of balance (on purpose) and watching for crossfilling.

 

 

[facthunter]

Some arrangements will allow air into the system from a low or empty tank while there is still plenty elsewhere. This is the worst possible outcome and why I will not trust a system that allows a large variation with both selected. You can design a system that will not let this happen. nev

 

 

[Dafydd Llewellyn]

I really think each tank should have it's own tap/valve. Pilots have more important things to think about than flying out of balance (on purpose) and watching for crossfilling.

Here are the relevant requirements from FAR Part 23:

 

§ 23.951 General.

 

(a) Each fuel system must be constructed and arranged to ensure fuel flow at a rate and pressure established for proper engine and auxiliary power unit functioning under each likely operating condition, including any maneuver for which certification is requested and during which the engine or auxiliary power unit is permitted to be in operation.

 

(b) Each fuel system must be arranged so that—

 

(1) No fuel pump can draw fuel from more than one tank at a time; or

 

(2) There are means to prevent introducing air into the system.

 

§ 23.957 Flow between interconnected tanks.

 

(a) It must be impossible, in a gravity feed system with interconnected tank outlets, for enough fuel to flow between the tanks to cause an overflow of fuel from any tank vent under the conditions in §23.959, except that full tanks must be used.

 

(b) If fuel can be pumped from one tank to another in flight, the fuel tank vents and the fuel transfer system must be designed so that no structural damage to any airplane component can occur because of overfilling of any tank.

 

§ 23.777 Cockpit controls.

 

(a) Each cockpit control must be located and (except where its function is obvious) identified to provide convenient operation and to prevent confusion and inadvertent operation.

 

(b) The controls must be located and arranged so that the pilot, when seated, has full and unrestricted movement of each control without interference from either his clothing or the cockpit structure.

 

© Powerplant controls must be located—

 

(2) For single and tandem seated single-engine airplanes, on the left side console or instrument panel;

 

(3) For other single-engine airplanes at or near the center of the cockpit, on the pedestal, instrument panel, or overhead;

 

(d) The control location order from left to right must be power (thrust) lever, propeller (rpm control), and mixture control (condition lever and fuel cutoff for turbine-powered airplanes). Power (thrust) levers must be at least one inch higher or longer to make them more prominent than propeller (rpm control) or mixture controls. Carburetor heat or alternate air control must be to the left of the throttle or at least eight inches from the mixture control when located other than on a pedestal. Carburetor heat or alternate air control, when located on a pedestal must be aft or below the power (thrust) lever. Supercharger controls must be located below or aft of the propeller controls. Airplanes with tandem seating or single-place airplanes may utilize control locations on the left side of the cabin compartment; however, location order from left to right must be power (thrust) lever, propeller (rpm control) and mixture control.

 

(h) Each fuel feed selector control must comply with §23.995 and be located and arranged so that the pilot can see and reach it without moving any seat or primary flight control when his seat is at any position in which it can be placed.

 

(1) For a mechanical fuel selector:

 

(i) The indication of the selected fuel valve position must be by means of a pointer and must provide positive identification and feel (detent, etc.) of the selected position.

 

(ii) The position indicator pointer must be located at the part of the handle that is the maximum dimension of the handle measured from the center of rotation.

 

(2) For electrical or electronic fuel selector:

 

(i) Digital controls or electrical switches must be properly labelled.

 

(ii) Means must be provided to indicate to the flight crew the tank or function selected. Selector switch position is not acceptable as a means of indication. The “off” or “closed” position must be indicated in red.

 

(3) If the fuel valve selector handle or electrical or digital selection is also a fuel shut-off selector, the off position marking must be colored red. If a separate emergency shut-off means is provided, it also must be colored red.