Safety Briefings

Mechanical Fuel Pump Failure - Bat Hawk with Jabiru 3300 Engine

by Charlie Marais



Bat Hawk with Jabiru 3300 Engine




An aircraft with two occupants on board experienced an engine failure during a scenic flight. The pilot initiated a glide to execute a forced landing onto the beach, which was approximately 49,2 feet (ft.) from the bush. During the glide, the pilot was unable to clear the bush. The undercarriage, keel bar, right wing and fuselage nose section were substantially damaged during the accident sequence. The pilot and his passenger sustained no injuries during the accident sequence. The aircraft was recovered by the insurance company and sent to Micro Aviation based in Mpumalanga for further investigation. The investigation found that the loss of engine power was probably due to interruptions of fuel flow to the engine, but could not conclusively determine the reason. The aircraft also stalled at a height insufficient to allow the pilot to recover.



Unsuccessful forced landing following loss of engine power inflight due to fuel starvation



·        Improper operating procedure of electrical fuel booster pump within restricted height

·        Dislodged fuel supply valve

·         Poor technique


Before we get into it allow me to state the following: I do not have it in for the pilot, the aircraft or the engine.  However, should we be able to learn from this unfortunate series of events, and I am sure we will, then it is worth commenting on.  The contributory factors section as published by CAA is not complete and void of some information that could lead to serious consequences.  No, I do not think they deliberately left it out of their short description in the report, but I feel it is sensible to regurgitate some of the unpleasant findings in the report.  The reason I feel justifies further referral to actions of poor repute, is that they give away who we actually are.  Okay, easy now, I am not saying that the pilot was to blame; he could just as well have been led astray by others who are either not known or mentioned in the report.   Then on the other hand, when I mention these pitfalls, it would once again be up to you to either take notice or cling on to the belief that there is a third force trying to stop flying fun.  But first a little reminder of what drives it all.

"The truth shall set thee free."  I apologise for starting with this one again, but I have to make some principles clear.    Standby, and please do continue reading, it may alter the way you perceive reality in the future.  Once again I will ask you to consider what the truth is, or even more precisely, what represents the truth?  I know one does not necessarily want philosophy when reading about flying, but then I do need a point of departure.

From the cradle to the grave we are driven by rules, regulations, norms, values, SOPs and so on.  I cannot think of a scientific truth, a behavioural truth, a cultural truth or the basic principles your parents taught you, that does not represent what we have established through the years as the truth.  All law, whether you like it or not, is a truth according to which you will be judged.  You may counter to say that there are many unspoken ways of behaving that are not recorded as a law and are only acceptable in a certain community.  Well, try and break any of the socially acceptable laws, spoken or unspoken, and the result will be negative.  The simplicity of the statement of setting you free lies in that when you follow the rules, you will be free from prosecution; free from judgement and free to not have to watch your step. You will have a better chance of being free from injury, damage to aircraft and even death.   It is as easy as that.  No confession about the past, nothing horrible, just follow the rules of your trade or community or environment and you will have a better chance of survival.  Following the rules will, or should never land you in trouble with any kind of authority.  You are free and therefore have a better chance of survival. Many aviation rules are written in blood and as I have said before, we are thankful, but we do not need yours as well. We are fully stocked with an overabundance of unrequired sacrifice due to the perception that we are smarter than the past one hundred years of accumulated knowledge, and skills, which form our current guidance in aviation.

Examples of straying from the published laws in this case are as follows and in no particular order of importance. The engine of this aircraft, a Jabiru 3300, actually does not exist.    It belonged to another aircraft that was allegedly lost at sea after an accident. However, the engine mysteriously re-appeared and was rebuilt.  The previous aircraft to which this engine belonged was deregistered as to the fact that the aircraft was irrecoverably lost at sea.  Now the engine is found to be the same one which in this case died on the pilot due to fuel starvation.  I do not know what you think, but I think I smell a rat.  What are the chances that an engine is reusable once recovered from the sea?  Absolutely zero, especially as it would have been there for a while.  But as the saying goes, where there is a buck to be made, there is the ever present possibility of clever bookkeeping.  Someone knows the truth, and usually others do not.  You buy a bargain and you take it to the shop. Here they charge you for fixing it and the regulator cannot trace the engine, unless of course you are so unlucky as to have an engine failure, in which case you cannot hide it.  What a rotten way to have the truth revealed.  In this case the previous ZU registered aircraft to which this engine belonged, was apparently destroyed in an accident in Mozambique on some remote beach, after which the waves dragged it into the sea.  The accident was neither reported by the effected state nor by the previous owner.  Are you also starting to smell something is off, or is it just me?  Well, apparently this accident was caused due to the fact that the then aircraft took in the wrong fuel grade, 95, and so the engine could not handle it and quit.  This is quite revealing.  A once of use of this fuel and it quits?  Again I do not think so, but when repeatedly used I would concede.  There are so many questions and so little clarity in this story.

This then leads to another truth or law that was, and in many cases, still are ignored.  The use of fuel grade.  The engine manufacturer clearly stipulates AVGAS 100/130, which we refer to in SA as 100LL or low lead fuel, but because this is more expensive in the short term, some opt for the longer term engine cut and loss of aircraft and life which is on offer.  Who is trying to kill aviation now?  My mother always used the saying, "Penny wise and Pound foolish." But then again, she was from the previous era, so what did she know?  Well, she understood that if you are cheap when quality counts, the results will always be more costly.  This has been proven time and time again.  Aristotle wisely observed, to his amazement, people fully knowing the truth (or rather what is wright versus wrong), but still electing to do what is wrong, totally aware of the possible consequences.  He ascribed this to lust.  The man definitely did mean sex, but he also meant a lust for money, power and all things that are outside of the acceptable norms and researched or accepted values.  In our accidents case, I could find no evidence that the fuel was tested, but the pilot claimed that he mixed AVGAS and normal petrol according to the aircraft and engine handling notes.  I will reserve my frown on this one and opt that it had a higher possibility of only containing normal octane and probably unleaded fuel.  But in this case it does not matter as the engine failure was not due to the fuel grade. 


Then the next truth is that the engine did cut due to fuel starvation.  There are two sides to this story.  Firstly, it was found that the mechanical fuel pump had dislodged a one way valve, which disturbed the fuel flow and caused an engine cut.  This was discovered afterwards during testing under certain power settings of the mysterious engine.  This then would account for the reason of an engine cut, but note well, which could have been avoided if the electrical fuel pump was activated below 1500 feet AGL - just one of the SOPs or truths that the manufacturer prescribes in the handling notes of the aircraft.  But, as electrical fuel pumps tend to wear and tear quite a bit, it has become standard practice by many aircraft and helicopter operators, where the electric fuel pump must be on below 1500 feet, to leave it off to prevent unnecessary maintenance costs.  As the engine does not cut often, we become used to it not having to be on and soon it becomes second nature to not follow the SOP. 

Another one of those things we do to save money is to work on the machine ourselves.  We all know this is done behind closed doors as long as we can get some guy that can sign it out, if so required.  The reasoning behind it all… "It is not that I am a qualified mechanic on any kind of engine, it is just that if it starts, surely I can change the oil?  If I can change the oil, surely I can do the inspection in accordance with the manufacturers guide?"  In this case the pilot did just that.  Unfortunately, it is not possible to prove him either competent or incompetent after the accident.  Did this have a direct effect on the cause of the accident?  Possibly not, but then how would I know, I am not a qualified mechanic or AME.

Then the last little button I have to push is that of low flying.  I do not want to spoil your fun, but seeing that you have the potential to spoil all ours, let me at least say the following.  The wise pilot will always leave himself with a better chance of recovery when something may go wrong.  Yes, this aircraft is built for observation and it is a great machine, I simply love it, but it cannot hover without an engine.  Oh, now the realisation that it is not a helicopter, it only has the view of a helicopter from the inside, but as a helicopter without height, this machine without potential energy to convert into kinetic energy or speed, forces the aircraft to land wherever the energy becomes spent.  In this case a great forced landing area was only 50 Feet away, but no matter the distance, energy is needed to achieve distance.  So how low did they fly?  Unfortunately the investigation did not stipulate any findings.  So how low is low enough to impress your passenger?


This is the part where I have to say wise things to wise men.  Wise, in this case, only means to know what is right and following it.  Let me begin with the aircraft engine fiasco.  I am in no way insinuating that the following was wrong, but remember that I comment on all possibilities.  My comments are therefore not necessarily factually grounded in this specific accident, but more principally referenced.

Oh yes, I was to comment on the engine saga.  Well, come to think of it, it is a rather bizarre story.  We all want to buy cheap, but no one wants to look cheap.  I have heard that it is all okay to skip the line, just do not be caught.  If you are caught it is because you were not clever enough.  It does not really matter as should any insurances be involved, they will, and it is their right, to clear the facts of any claim.  This would have been an interesting one.  I recommend two things in this case; firstly do not look for a cheapie and if it is too good to be true, it certainly in most cases cannot be true.  I would not bet my life on a bargain that is not verifiable. Flying is not a bargain sport.

An engine recovered from the sea?  I have never heard of such rebuilds, but then again, if this is normal and standard practice, I would like to learn more about it.  My opinion is that the engine was never in the water.  Note that the engine did not cut due to being a poor engine, it was just a mechanical failure which lead to fuel starvation.  The recommendation here is that one must always buy parts that are traceable.  It may take your life and then again it may not.  Whatever the worst possible scenario could be, is it worth your life?

Mechanical and electrical fuel pumps all have a very specific function.  The electrical is always there to back-up the mechanical one and visa-versa.  For the electrical pump to function it needs to be serviceable and made functional in the time between when a mechanical failure occurs and when you have run out of height.  If you have no time to deploy your standby, why have it at all?  Manufacturers will always advise you to the best practice, while your financial auditor may disagree when the parts need to be replaced due to actually working wear and tear.  My advice would be to always follow the manufacturer's instructions.  There are many deadly reasons why a safety feature was designed and installed.  Fuel starvation due to the non-usage of safety features will always point to an individual's decision.  To say that it was not recommended is simply not true as the manufacturer actually does so in writing.  Why is it that we always believe our buddies who actually got the information second-hand from untraceable sources?  Remember, to get away with it for 600 hours, just an example, does not guarantee the next hour.  Statistics have already proven that the safety feature was actually necessary.

When I start talking about the fuel grade used, many already have a thousand reasons and excuses, again not one is reputable.  The reason I can say this is that if we think about this clearly, no manufacturer can afford to advise their clients in a way that suits everyone's pockets, but rather what engineering has proven to be the best.  The engineers building these engines have done so with very specific performances in mind and have nothing to gain by us using the wrong octane or fuel blend. Their reputation is on the line, so their advice as written in the handling notes is the proven best.   Okay, so you still think it is a capitalistic scam.  Well, just ask yourself why so many of these specific engines do not last their design life?  And are you really telling me that you mixed the fuel?  Thousands may believe you, but I surely won't.  My advice again is to use what the manufacturer of these engines recommend in their operating manuals and not what your best buddy says. 

Now for the one that we all believe is responsible for killing our beloved sport.  The cost of servicing the aircraft and engine.  Costs are spiralling out of control.  The parts are imported and are becoming absurdly expensive.  To boot, the AMOs are asking an arm and a leg to do the prescribed servicing.  I am not in any way denying that costs have made the sport sour.  The catch 22 now reveals that if I use bogus parts, or bogus service personnel, the end is also a dying sport.  The obvious answer is to use cheap parts and cheap labour.  The reality, unfortunately, is that with the cheap comes a definite portion of sorrow.  To skip the rules is always an option and one that is easily succumbed to.  I can only advise that parts must be the real deal, or the outcome is seldom predictable.  I hear you say; "but surely this nut can have no adverse effect?" The vibrations an aircraft endures, the bending and twisting of the frame and attachments are clearly not understood by every pilot.  Some could probably argue that certain aircraft parts may have no relevance, being bogus or original, to safety.  I mean so one can think, but only until the alternator came loose during flight, the exhaust clamp fell off, the engine retainer nut or bolt broke due to DIY shopping.  The truth is AME's are taught to not use bogus parts and it is not their fault that they cost so much.  If you can get some discount on the servicing, good for you, but to do it yourself will always leave the door open for that small item you missed because you were unaware of it.  If it was like servicing a car, any mechanic could have been used, but you see, this is not a car.

Just a question; who would you use to service and check your spacecraft when you are off to the moon?  I believe you would use the best service personnel, the best parts and the best paperwork to follow.  Well, look at it this way, every time we defy gravity, we might as well have gone to the moon.  In both cases, falling out of the sky can have serious consequences.  To fly five or fifty miles makes no difference in the aerodynamics or mechanics.  I urge you to treat your life with equal respect irrespective of the distance, unimportance, or perceived lack of danger of the sortie.

So, life will happen, but through application of the "truth" we will all have a better chance of keeping aviation alive.  Seek the SOP, know the SOP and then apply the SOP, your family deserves it.

Charlie M (3043)