An argument for the experimental, light sport header
tank!
Some light sport pilots spend much of
their flying time within a relatively
small area around local airfields – well within- at most: an
hour of flying time before landing.
These pilots
don’t need to top off their fuel
tanks, as the required safe amount of gas required for an hour of flying- plus
the required ˝ hr. of reserve time is
less than 10 total gallons (for example: at 5 gallons per hr. burn rate for a
typical light sport engine).
If you have 2 wing tanks, that would
be no more than 5 gallons per side of useable fuel for your local flying
excursion.
But most of us know that using your
fuel gauges, you cannot judge the last 5
gallons of useable fuel in your tanks; these gauges are widely inaccurate
when judging fuel level.
The typical solution:
just load up with LOTS of extra fuel on each side and be done with it! We
don’t want to worry about running out while flying.
Extra fuel is the answer!
Here is the problem:
throwing an extra 5 gallons “for safety” into each
wing adds about 60 lbs. of weight to your aircraft – weight that is
present just to make us feel secure that we won’t run out – even for those local
trips of less than hour around the patch.
No surprise: there is a substantial amount of useable fuel left in our wing
tanks even when the gauge reads empty: but the problem is – just how much??
Your life and safety is not worth the gamble to find out.
Have you ever come close to running out of fuel because you misjudged the level in the tanks…
and the resulting pucker factor will not let you ever forget?
(We are ALL human, after all – mistakes can and will be made in our
lifetime).
Didn’t we work REAL hard while
building our plane to watch for adding any extra weight – even to the point of
analyzing options down to the ounces and pounds before putting them in our
aircraft? And now that we are flying
– we throw an extra 60 lbs. of dead
weight (fuel) – just because we cannot accurately understand how much useable
fuel we have on board?
For those of you who haven’t flown
your aircraft yet- maybe you are still building at this time – let any pilot
that flies a light sport warn you that keeping the weight down as much as
possible means your plane will perform so
much better in the air! DO work at keeping the weight off!
You will later have to experience to believe!
The header tank is a GREAT solution
for this problem Note: I spend 75% of my
flying time visiting local airstrips, my flying time is well within an hour and
fuel is always available.
The header configuration is as follows: With
a high wing homebuilt aircraft, both wing tanks are plumbed into a common 2
gallon header tank (header tank size is your choice…keep in mind mounting
restrictions and weight).
The header tank then feeds the engine. This way
all fuel from both tanks MUST flow thru the header tank first. The
header tank is always FULL until: the last useable drop from both wing tanks is
consumed. This is typically long after the wing tank gauges read empty!
If the header tank fuel gauge starts moving off FULL, you know you have
reached the point where the wing tanks are no longer contributing to the header.
By monitoring
accurately the level in a 2 gallon
header tank, you can know and watch the approximate last half hour of fuel
before the engine stops. There is no guessing when that time has come – the
needle on the gauge will move like a minute hand… steady towards the last ounce
of fuel. What you decide to do
during that last half hour is your choice (Land!). With this setup, you now have
ability to accurately monitor your fuel level like never before! (Even expensive
fuel flow gauges fail to inform when there is an unexpected loss of fuel from a
wing tank due to a leak, etc).
These are my own opinions and findings
– your experience will vary. I
really enjoy flying a lot more now that:
I have eliminated that nasty feeling flying when close to empty
(Did I estimate my flight time and fuel reserves properly for those longer
trips?) We need to always plan carefully for fuel managementand provide for the
mandated reserve – the number one
cause of accidents – but it is quite a
safety feature to have awareness your last half hour of flight, minute by
minute down to a “science”.
My aircraft is performing at optimum levels because I have eliminated 60 lbs. of
dead weight!
(Take off distances, flight speeds,
maneuvering performance, etc. -
everything is affected adversely by weight).
The benefits from 60 lbs. of weight reduction is not as evident on much
heavier, certified aircraft. I am
only referring to the magnitude of benefits with light sport class aircraft!
Of all the efforts I made to eliminate
excess weight from the plane while building, the installation of a header tank
was the significant winner by far!
Jon Croke
Comments? YouTube video: HEADER Tanks