Kaaaarl, my Airbus won't start!

[Chock 17,769]

A tale of dead airlines and potential problems with the undead....

Despite Thomas Cook Airlines having folded way back in September of last year, there are still several airliners sat at Manchester Airport wearing the Thomas Cook livery. Most of Thomas Cook's A320s, A321s and A330s were towed onto the remote stands at the time of the firm's collapse and were then impounded, pending airport fees being paid. However, in the weeks following the airline's collapse, most of these aircraft gradually disappeared from the ramp, of necessity, since they were taking up a great deal of room. But four A330s remained, one was in the enormous Thomas Cook (now acquired by Jet2) hangar on the Fairey Apron, and the three others were parked up on stands 65 and 66, the one in the middle of these three facing the opposite way so that they could be placed closer to one another and take up less room.

Five months on and with the approach of the summer flight schedules, Manchester had to look at moving these aircraft out of the way, so for the past couple of weeks, engineers have been working on the engines of these aircraft and presumably doing all the other bits necessary to get them airworthy. As I understand it, Virgin and Jet2 acquired these aircraft some time ago, but for most of the time they've just been sat there with engine covers on since they would notbe needed during winter. So the other day, these aircraft were towed off those stands and moved to stands 807, 809 and 811, where they can be seen in this picture, which I took from the cab of a truck on Stand 70L today:

There'll be a fair bit of work necessary to get those TC A330s ready to fly, and some of that work will be quite unusual and not something most people would think about... 

If left standing for a long period of time, the fuel tank of an airliner will start to accumulate microbes. In fact, it really doesn't take long for this to start occurring, but most of the time it is dealt with by occasionally draining the tanks a little through a vent in the bottom of the wings, since the bottom of the tank is where small quantities of water accumulate. If present, microbes start off living in that small amount of water, particularly if it is not drained regularly, but as these microbes multiply, they start living elsewhere in the fuel system, including in fuel lines and filters etc, or just about anywhere where they can feed on the hydrocarbons in the jet fuel.

When these organisms feed on the fuel's ingredients, naturally this degrades its quality, but it also does another thing which is surprising; it can start to cause the fuel gauges to read incorrectly. This is because the fuel gauges in an airliner function by measuring the electric capacitance of the fuel in the tank, and from the fuel's known ability to hold a certain amount of electrical charge per gallon, the aircraft systems can work out the fuel quantity in the tank by the capacitance value. Since those microbes have a different capacitance than jet fuel, the gauges will start showing incorrect readings if there are a lot of those little bugs present, which is one of the ways you can tell this problem is occurring.

Another thing which is an interesting side effect of this, not to mention sometimes being a clue as to whether an airliner has got a large quantity of microbes living in its fuel system, is if there is a problem with the fuel filters when the engines are at high thrust settings. Most jet engines on airliners have a set of very fancy fuel filters, yet unlike the fuel filters on a typical car, the fuel filters on a jet airliner's engine have an automatic system which will bypass the filters if a sensor detects that a filter blockage is restricting fuel flow, and guess what is one of the most common causes of a fuel filter blockage? Yup it's those microbes creating a sludgy mess which blocks the filter. So when the aircraft is required to use its engines at high power settings without any glitches (such as on take off), in order to not restrict the flow of fuel if a filter blockage is detected, the aircraft's systems will choose to bypass the filters to ensure a good fuel flow. However, since this means the engines are using unfiltered fuel, the system will report that this bypassing is occurring. So if you see a system message that the fuel system is bypassing the filters, it can mean that it's time to disinfect the fuel system to get rid of those microbes.

Contamination from microbes in fuel also occurs with cars and trucks and motorcycles etc if you leave fuel in those for a long time, which means when you watch those zombie apocalypse movies where people are still finding cars which work several years after the apocalypse merely if you charge the battery a bit, now you'll know that it's unlikely they really would. So with The Walking Dead now on Season 10, in reality, the living would mostly be walking too, because pretty much all the cars would be in dire need of a really good service, and so would the aeroplanes.

You'll be pleased to know that guns and crossbows would work just fine though, so definitely have some of those around if the zombie apocalypse comes.

 

Edited February 18, 2020 by Chock

[overspeed3 410]

So. what's happening to to the fuel tanks of the many hundreds of B737 Max aircraft grounded worldwide?

 

[Chock 17,769]

4 hours ago, overspeed3 said:

So. what's happening to to the fuel tanks of the many hundreds of B737 Max aircraft grounded worldwide?

 

I would assume that the tanks have probably been drained and flushed out with some sort of protective detergent or anti-fungal wash. I know there are companies which provide such services for testing and dealing with such issues, but I don't know the actual materials they use. Someone told me that engineers occasionally faff about with the five TUI MAXs which are parked up at Manchester near the end of Runway 23, presumably to prevent the tires getting flat spots etc.

I suspect they might have occasionally cranked the engines up (which would of course require them to have fuel on board), but I don't know that for sure because the only time I end up anywhere near those MAXs at Manchester is when we do a long pushback to Golf 3 off stands 49-54 and even then we don't end up that close to them. I do see those TUI 737s from some distance away when coming past the airport on the way in to work, but from that distance all I can tell is that they have their engine covers on. Actually, if it is quiet at work today, I might have a drive out to them and see what they are like.

What I do know is that if they have not done any of that sort of thing, the contaminants in the fuel systems can be corrosive, so I would assume Boeing have either issued some kind of directive to operators on what to do to prevent this, or possibly Boeing may have a support program which deals with that kind of issue. It's unlikely that Boeing would have done nothing about it.

The issue with those ex Tommy Cook A330s, is that for a while they were probably not the responsibility of any engineers at all whilst the receivership of the company's assets was being dealt with and confusion reigned over whose responsibility they were, although sometimes, the engines and tires on aeroplanes are not owned by the airlines and I think it was Rolls Royce who actually owned the engines on those A330s, so you would think they might have been doing something about them if they thought it was an issue. But as far as I'm aware it was only fairly recently that anyone appeared to be doing any work at all on them, and when they were on Stand 65 I did drive right past them and park near them on most days at work because they were right next to the West Gate airside entrance, which is where we go to collect and drop off cargo (which I always seem to get lumbered with doing lol), so I'm pretty sure I would have noticed any work being done on them. When I worked for Aviator (who were the company I worked for which had Thomas Cook as their main client) we did tow them to those locations originally, but after I lost my job with Aviator as a result of Thomas Cook folding and went working for Menzies Aviation instead, I and everyone else who had worked for Aviator ceased to have anything to do with those aeroplanes. As far as I'm aware, it would probably have been RGF which towed the A330s to their new location and I think it is Storm Aviation who are dealing with them now, certainly it was Storm which took over the engineer duties for all those rescue flights we did back last year which repatriated all the people who were stuck abroad after Thomas Cook folded. I know a lot of the ex Thomas Cook engineers went working on Jet2 A330s because they serviced the Air Tanker A330 which Thomas Cook had leased and it was Jet2 which ended up leasing that one, so they might possibly have still looked after those A330s given that I think Jet2 bought one of the ex Thomas Cook ones and it may possibly have been Virgin's engineers doing a similar thing given that I think they bought one as well.

[vadriver 247]

alan

is there ever a dull day at EGCC airside ...... it looks so organised at +15' agl.

[Chock 17,769]

1 hour ago, vadriver said:

alan

is there ever a dull day at EGCC airside ...... it looks so organised at +15' agl.

Appearances can be deceptive lol