September 2003

Time for a leak?                    Return To Buck Rogers Aviation

Fixing fuel tanks

Our pre-purchase inspection had revealed some expensive looking fuel leaks. A quick call to Buck Rogers Aviation had Mike de Villiers and I scurrying off to Lanseria after Buck invited them to bring the tanks in to his workshop where he could pass judgement on their condition.

Some of you will remember the long list of snags revealed during "FPI's" pre-purchase inspection. Golden Wings Attie Pinaar unveiled a tale of general neglect as he added up the myriad number of items needed to get our 182 airborne again even though it was a mere six months since its last MPI. Although sometimes difficult to detect, especially if fuel tanks are left partly filled, Attie could not miss the tell tale signs of some nasty fuel leaks. Suspicion was cast during our demo flight when I detected the insidious aroma of avgas leaking into the cabin and the telltale signs of stained headlining. Sure, this may have been a loose fuel line jubilee clip but the stains further manifested themselves on the underside of the wing. Was this going to be another big expense item?

So far, the most expensive item has been the new exhausts and after calling around to a number of parts suppliers, Comair offered the best price at R25 498.72. Mike had made tentative enquiries about replacement fuel bladders - priced at R7 500 each - a not inconsiderable sum. Attie suggested we extract them to see if they could be repaired and in no time I was on the phone to Buck Rogers Aviation in Midrand where a very pleasant and knowledgeable Patricia Dean soon grasped the problem.

Those of you who have been around aeroplanes for a while will know Buck and Patricia well. Buck was the chief bottle washer at his Grand Central-based AMO. Early this year he closed down his maintenance emporium having reached his wits end dealing with awkward customers and lists of defaulting aircraft owners who offered every excuse under the sun to avoid keeping their aeroplanes in tip top condition and paying their maintenance bills. Enough was enough, said Buck and he shut up shop and moved to a very nice plot in spitting distance of the Vodaworld building alongside the Pretoria to Johannesburg highway.

Buck has been in the aircraft fixing business for some 40 years and there's not a lot he hasn't seen or doesn't know. Some years back he became frustrated at continually replacing fuel bladder tanks. Frustrated because of the time to obtain replacements from the USA and their seemingly high cost. After a bit of head scratching, Buck realised the bladders could be repaired to the satisfaction of the FAA and thus our own DCA. This wasn't some new revelation, work of this nature was accepted business in the USA.

It isn't the cleanest of tasks and the gooey and dirty nature of tank repairing had discouraged others from adopting this practice. Discouraged not one whit by the potential mess, Buck got into the tank repair business and over the years he has grown to a thriving niche supplier to the region's AMOs. Unsurprisingly, this busy corner of his shop was not dispensed with when Buck waved goodbye to Grand Central. Today, this business thrives and Buck has gotten into other related areas including the lucrative manufacture of automotive fuel tanks.

With no promises, Patricia invited me over to inspect their workshop and suggested we remove FPI's bladders and bring them over for inspection. Fired up, Mike climbed up the ladder with a screwdriver in hand to lend help to Sello Motshele and Big Boy Sebogo and the three of them proceeded to remove the access hatches - four of them on FPI. The tanks are attached inside the wing with five clips on the upper surface and a similar amount of studs on the lower surface. These keep the bladder expanded as fuel is used. The feed nipples were then detached from the fuel lines at the wing root. Sello rolled up the tanks inside the wing and carefully withdrew them from the inboard access panels having made sure that the drains on the underside had been removed. Within an hour and a half, the tanks lay on Attie's workshop floor.

Relieved that we may have to avoid the cost of new tanks, I collected the two long range bladders a couple of days later, loaded them into my car boot and set off for Midrand. Buck and Patricia were ready for my visit and within minutes had the tanks laid out on their inspection table for a visual assessment, a cleaning with soap and water followed by a pressure test having put in five litres of fuel and then sealed off the fuel feed nipples and filler hole. The bad news soon followed there were three leaks in one tank and four in the other. Before I could digest this, Patricia said the bladders were otherwise flexible and in reasonably good condition and yes they could be repaired.

Before you Cherokee owners sniff and say "yeah our Piper's use aluminium tanks', it' worth remembering that there's an 80-percent less chance of fire in an accident than with rigid or wet wings. Our 1969 182's tanks were of dissimilar manufacturing dates and manufacturers, indicating previous problems. One tank had been made by Uniroyal in 1979 and the other by Goodyear in 1970. Buck prefers Uniroyal tanks saying they seem to stay softer than others. The bladders can last a long time, sometimes up to 30 years. I was shown a tank newly removed from an early pre-sixties 182 and Buck said with little hesitation that the owner had probably kept them full empty tanks leads to early degradation of the rubber. Moreover, fuel bladders do not store well and the best place for them is in the wing.

The next repair stage was to thoroughly clean both the outside and inside surface with Methyl Ethol Ketone - or MEK as it's known in the trade. This is followed by buffing the areas around the leaks with sandpaper to offer as best a surface possible for the Phenol Phaylene sealant to bond with. Each hole is thus treated and two leaking nipples replaced with new ones. The holes are then patched, as is a split around one of the access holes. Buck's team is obviously very experienced, two of them, Chauke "Sputla" Sello and Johannes "Snarks" Meboa have repaired and installed over 4 000 fuel tanks - they know their stuff. The last stages are to allow the sealant to dry and then to pressurise the tanks again as a final check against further leaks followed by a complete coating of rubberised paint before the bladders are stored ready for installation.

Buck Rogers Aviation is no slouch and no sooner had I returned from Oshkosh than Patricia was on the phone to arrange an installation date. This level of service always impresses me, especially when, for a change, it is the service provider that is pro-active in getting the job done. Patricia arranged to bring the tanks to Lanseria for Sputla and Snarks to fit. This process is always carried out by Buck Rogers as things can go wrong during installation and the company has a warranty to honour. A poor job might open another hole as has been discovered by owners who allow their regular AMO to re-install the bladders.

Although this type of tank repair is usually a three to four day task, my overseas trip meant there was a couple of weeks gap and I wanted to be there as the repaired tanks were installed. A day after returning to South Africa, I met up with Patricia, Sputla and Snarks at Golden Wings to install the bladders. The first move was to lay out the rubber tanks on the ground and in the sun to soften them up. They were then covered in talcum powder, again to help their passage through the small diameter panel on top of the wing.

The team then climbed onto the wing and applied sticky tape over the inside rivets and skin joints to prevent chafing. The tanks were carefully furled up and fed through the access ring and into the wing apertures before the clips and studs were correctly located. Sputla pulled the feed pipes through into the cabin via the holes in the wing root. Importantly, the "sniffle" valve, which lets in air as fuel is burned up is then attached to the left hand tank as is the cross-over balancing tube that allows fuel to feed equally when the selector on the cabin floor is turned to the "both" position. Finally, Attie is invited to double check Sputla and Snark's work as it is Golden Wings that has to sign off the installation.

A tank repair job can be a real money saver and in our case it was particularly gratifying to see how Buck Rogers Aviation got stuck into the task with a high degree of customer service. This area of aircraft maintenance is not always so smooth. According to Patricia, removing the tanks can be a wise decision, especially as some AMO's may recommend a complete new replacement in order to maximise profits. There are many stories of maintenance companies recommending owners buy new fuel cells without actually removing the existing bladders and submitting them for repair. For us, the cost of our 182 fuel tank repair was about R4 000 including installation a big saving over buying new ones.

Despite the apparent simplicity of bladders, there have been some ADs over the years. For instance, if you are unfortunate to have Goodyear BTC-39 tanks installed (made between 1960 and 1970), these must be condemned when removed. In 1990 an AD mandated the addition of a vent and additional nipple on left hand Cessna 180 tanks. Then there was the famous 1984 AD that attempted to address leaking filler caps, wrinkles and problems with the quick drains affecting Cessna models from the 180 to early 210s. There have been various attempts to resolve the inevitable wrinkle problem, which can trap water. This is a perennial situation as we saw in FPI's bladders and the industry has yet to discover a method of removing them. However, keeping the tanks full and filler caps well sealed (despite Africa's problem with fuel theft) is the best way to keep water out and maintenance bills low. And before you Cessna owners weep at the cost of new fuel tanks spare a thought for hapless Aero Commander owners who are faced with maintaining and replacing all their 22 separate wing bladders!

Buck Rogers Aviation can be contacted on +27 11 318 0220 or email triciadean@mweb.co.za