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vector
September / October 2009
Pointing to Safer Aviation
Changes Proposed for
Agricultural Aviation
Asymmetric Flight
Dipsticks
Taildraggers 101
vector In this issue...
34
Changes Proposed for
Agricultural Aviation
Changes Proposed for
You can participate in the rule development
process. We remind you how to get
Agricultural Aviation 3
involved, and mention some of the changes
proposed in the soon-to-be released Notice
Asymmetric Flight 4
of Proposed Rule Making (NPRM) for
Part 137 Agricultural Aircraft Operations. Which Runway Are You Going For? 8
Dipsticks 9
Prop Strikes 12
4
CAA to Relocate in Central Wellington 13
Asymmetric Flight
Taildraggers 101 14
Asymmetric flight is an exercise that
must be practised regularly. However, Flight Instructor Seminars 17
in light twins, that practice can be more
dangerous that the real life engine failure.
Airspace Changes 18
Practising must never put the aeroplane
in danger.
Competently Current 20
Aviation Safety Advisers 21
IFIS Met Now MetFlight GA 21
9
Icing Correction 21
Dipsticks
Director’s Awards 22
The fuel dipstick is a very reliable way to
measure the amount of fuel in your aircraft GPS Equipment Maintenance 23
tanks, but it is often a misunderstood tool.
Here are some reminders about dipsticks, Flight Training Changes 23
usable and unusable fuel, and aircraft
empty weight. New Products 24
Planning an Aviation Event? 24
How to Get Aviation Publications 24
14
Accident Briefs 25
Taildraggers 101
What’s New? 26
The short-field performance and prop
clearance of many taildragger types make GA Defects 27
them a logical choice if you are interested
in strip flying. Here are a few basics to get Photo Competition 28
your head around before your first lesson.
Cover: Ray Patchett, owner and pilot for Omaka based
company Patchett Ag Air, is seen here spreading lime
on a vineyard in the Awatere Valley with the Gippsland
GA200 Fatman. Photo: Gavin Conroy
Published by Publication Content Free Distribution Change of Address
The Communications and Safety Education Unless expressly stated as CAA policy, the Vector is distributed automatically to all Readers receiving Vector free of charge
Unit of the Civil Aviation Authority of views expressed in Vector do not necessarily New Zealand flight crew, air traffic controllers, should notify info@caa.govt.nz of any change
New Zealand, P O Box 31–441, reflect the policy of the Civil Aviation Authority. aircraft maintenance engineer licence holders, of address, quoting your CAA Client Number.
Lower Hutt 5040, New Zealand. Articles are intended to stimulate discussion, aircraft owners, most organisations holding Paying subscribers should notify The Colour Guy.
Tel: +64–4–560 9400, and nothing in Vector is to be taken as an aviation document, and to certain other
Fax: +64–4–569 2024, overriding any New Zealand civil aviation persons and organisations interested in Paid Subscriptions
Email: info@caa.govt.nz. legislation, or any statements issued by the promoting safer aviation. Vector is available on subscription only from
Published six times a year, in the last week Director of Civil Aviation or the Civil Aviation The Colour Guy, P O Box 30–464,
Authority of New Zealand. In the case of flight crew and air traffic
of every odd month. Lower Hutt 5040, Freephone 0800–438 785.
controllers, a current aviation medical
Reader comments and contributions are certificate must be held, and a current
Manager Communications Bill Sommer. Copyright
welcome and may be published, but the Editor
New Zealand address given, to ensure Reproduction in whole or in part of any item in
Editor Peter Singleton. reserves the right to edit or abridge them, and
magazine entitlement. Vector, other than material shown to be from
Safety Education Publishing Team not to publish those that are judged not to
contribute constructively towards safer aviation. Holders of Pilot Certificates issued by Part 149 other sources or named authors, is freely
Lakshmi Guda, Cliff Jenks, Anna McClay,
Reader contributions and correspondence certificated organisations can also apply to permitted, providing that it is intended solely
Clare Ferguson, Rose Wood.
regarding the content of Vector should be receive a free Vector (see the CAA web site for the purpose of promoting safer aviation,
Design addressed to: Vector Editor, P O Box 31–441, for details). Vector also appears on the CAA’s and providing that acknowledgment is given
Gusto Design & Print Ltd. Lower Hutt 5040, or email: info@caa.govt.nz. web site: www.caa.govt.nz. to Vector.
2 vector September / October 2009 ISSN 1173-9614
Changes Proposed
for Agricultural Aviation
A Notice of Proposed Rule Making (NPRM) on amendments to Part 137
Agricultural Aircraft Operations is due to be released soon.
T
he proposals should have no believes the changes proposed to the active Part 137 certificated operators,
surprises for those in the industry rule will help them do that. The proposed 97 aeroplanes, and 133 helicopters.
– they have been discussed at changes will help create a level playing
To be alerted when the NPRM is
previous annual conferences, and a field, and establish some standards that
published, subscribe to our email
project working group of industry will assist operators to better manage the
notification service, www.caa.govt.nz/
participants has been involved in the safety of their businesses.”
rule development since March 2008. subscribe. This notification will include
There are a number of proposals in the closing date for submissions.
John Fogden, CAA Manager Rotary the NPRM, including: certification under
Wing and Agricultural Operations, says, Part 137, fatigue management, chief The NPRM is published so that all
“At the Agricultural Aviation Association pilot responsibilities, training and super- interested parties can have their say
(AAA) conference held in Blenheim in vision of junior pilots, seat restraints, about the changes proposed. You can
determination of hopper contents, find out more about having your say, and
July, there was a strong message from
and the overloading determination in
the industry itself that the agricultural the whole process, in our free booklet,
Appendix B.
sector has an unacceptable safety record. The Rule Development Process – just
The membership was urged to take The agricultural aviation industry curr- email info@caa.govt.nz for a copy.
ownership of the situation, and the CAA ently consists of approximately 112
vector September / October 2009 3
Asymmetric Flight
An engine failure after takeoff (EFATO) will be the most
performance-critical manoeuvre in your twin-engine life.
T
his emergency happens close to the ground, at low Climb performance depends on four factors:
airspeed, at the heaviest point of the whole flight, and »» Airspeed – too little or too much will decrease climb
asks the remaining engine to operate at its maximum performance.
available power setting. Not a situation to be taken lightly.
Add to that the need to accurately control the aeroplane, carry »» Drag – gear, flap, cowl flap, prop, and speed.
out the emergency actions, and follow the Standard Instru- »» Power – amount available in excess of that needed for
ment Departure. It makes you tired just thinking about it. level flight.
There is a need to practise this, so you are well prepared »» Weight – passengers, baggage, cargo, and fuel load greatly
should you be unlucky enough to face this in real life. affect climb performance.
Unfortunately, there are more accidents because of simulated
EFATO, than because of real EFATO. That does not negate the Yaw
need for practice – it just illustrates the need for a heightened
Immediately following the failure of one engine, yaw is caused
awareness of the dangers.
by asymmetric thrust and displacement of the total drag
The most critical things you lose, when you lose power from towards the inoperative engine. Yaw forces must be balanced
one engine, are climb performance and controllability. with the rudder (or by reducing power on the operating engine)
(see Figure 3).
Climb Performance Loss of power on one engine reduces slipstream (and induced
Climb performance depends on excess power. Loss of power lift) over the wing. Yaw also affects the lift distribution over
from one engine obviously represents a 50 percent loss of the wing, causing a roll towards the inoperative engine.
power, but in virtually all light twins, this results in a reduction These roll forces may be balanced by banking towards the
of climb performance of at least 80 percent (see Figure 1). operating engine.
The amount of power required for level flight depends on how If a small bank angle (about five degrees) is used towards
much drag must be overcome to sustain level flight. Clearly, the operating engine to help counteract the yaw, a smaller
drag is increased if the gear and flap are down and a prop is rudder force will be required. Since the displaced rudder
windmilling, and more power will be required to overcome increases drag, any reduction in rudder angle will lessen the
this. You may need to reach down into the memory banks, drag, and performance will be improved. Think of it as
however, to remember that drag also increases as the square ‘raising the dead’ and then you will remember to raise the
of the airspeed, and power required to maintain that speed wing with the dead engine.
increases as the cube of the airspeed (see Figure 2).
800
700
Vertical speed
Percentage of increase
+
600
0 e
d
s pe
500 air
in
ta
- ain ed
400 m pe
d to
t h airs
e i
u ir es w
300 req incr
eas
er a g
Indicated airspeed Po
w D r
200
Twin-engine climb One engine inoperative,
prop windmilling 100
One engine inoperative 100 110 120 130 140 150 160 170 180 190 200
and minimum drag One engine inoperative, gear and
flaps down, prop windmilling Airspeed (knots)
Figure 1. Effect of inoperative engine and aircraft configuration on Figure 2. Effect of airspeed on drag and power required to maintain that
vertical speed. airspeed in level flight.
4 vector September / October 2009
Photo: ©istockphoto.com / Ken Babione
Critical Engine Airspeed
The critical engine is that engine, which failed, would most Airspeed is the key to safe single-engine operations. There are
adversely affect the performance or handling qualities of the a few you should be familiar with:
aeroplane. The critical engine on most US-manufactured light
VMCA Minimum control speed airborne.
twins is the left engine, as its failure requires the most rudder
force to overcome yaw. VSSE Airspeed below which an intentional engine cut should
never be made.
In level flight, the thrust line of each engine is through the
propeller hub. But at low airspeeds and high angles of VYSE Best single-engine rate of climb speed.
attack, the effective thrust centreline shifts to the right on each VXSE Best single-engine angle of climb speed.
engine, because the down-going propeller blades produce
more thrust than the up-going blades (called asymmetric V1 Decision speed.
blade effect, asymmetric propeller thrust, or P-factor, see V2 Takeoff safety speed.
Figure 4). Therefore, the thrust line of the right engine moves
further from the centreline of the aircraft (giving a longer VMCA – Minimum Control Speed Airborne
lever arm), resulting in greater yaw and more rudder needed VMCA is designated by the red radial on the airspeed indicator,
to counterbalance the yaw. and indicates the minimum speed at which you can still control
Twins with counter-rotating propellers don’t have a critical the aeroplane while airborne, at sea level.
engine.
Continued over »
Thrust from
Off-set thrust lines
operating engine
due to “P-factor”
Drag from Direction of
inoperative yawing tendency
engine
Counterbalancing Counterbalancing
force exerted by force exerted by
rudder rudder
Figure 3. Yaw. Figure 4. Engine thrust line shifts to the right at low airspeeds and high
angles of attack.
vector September / October 2009 5
» Continued from previous page
VMCA is determined by the manufacturer as the minimum VMCA well before the stall onset, the exercise may need to be
airspeed at which it is possible, after a sudden failure of the carried out at a lower level.
critical engine, to recover directional control of the aircraft
Recovery from VMCA should start as soon as the pilot has lost
within 20 degrees heading change, and then maintain
directional control by five degrees, but it is imperative that
straight flight with no more than five degrees of bank, in the
recovery is made at the first sign of any stall onset. If the yaw
following configuration:
coincides with the stall, or soon after, a spin will be the most
»» Takeoff power on both engines. likely result. Some light twins have not had spin recovery
demonstrated, and the likelihood of you recovering would
»» Rearmost allowable centre of gravity.
be remote. Consequently, it is not advisable to fly at speeds
»» Flap in takeoff position. approaching VMCA, except in training situations or during
»» Landing gear retracted. flight tests, where you have a qualified multi-engine flight
instructor with you.
»» Propeller windmilling in takeoff pitch configuration
(or feathered if automatically feathered). Recovery from flight at or below VMCA is made by reducing
Sudden engine failures rarely occur in this configuration, power on the operating engine (to stop further yaw),
however, and therefore the actual VMCA may vary. while decreasing the angle of attack by lowering the nose.
Immediately following this initial recovery, power is returned
For instance, VMCA decreases when the propeller is feathered, to both engines, and the aircraft accelerated back to a
or when power on the operative engine is reduced, or when safe speed.
the C of G is forward of the rear limit.
Other factors affecting this minimum control speed include: VSSE – Intentional One-Engine-Inoperative Speed
VSSE is specified by the aeroplane manufacturer and is the
»» Turbulence – which will effectively increase VMCA because
minimum speed you can intentionally fail an engine. The use
the pilot cannot control the aircraft as precisely as they
of VSSE is intended to reduce the potential for an accident
otherwise might.
arising from loss of control after an engine failure has
»» The strength and skill of the pilot – we are not all test pilots. been simulated at, or near, minimum control speed.
»» Pilot seat position – so that full and sustained rudder VSSE demonstrations are necessary in training but should
deflection is possible. only be made at a safe altitude above the terrain and with
the power reduction on one engine made at, or above, VSSE.
Practising VMCA Power on the operating engine should be set at the position
Extreme caution must be used when undertaking minimum for maximum continuous operation as airspeed is reduced
control speed exercises. With some aircraft, VMCA occurs below slowly (one knot per second), until directional control can no
VS at all altitudes. When this is not the case, there is a point longer be maintained, or there is any indication of stall onset
where the single-engine power-on stall speed will correspond (see Figure 5).
with the VMCA line (see Figure 5). In this situation, the instructor
may need to promote the loss of directional control in order VYSE – Best Single-Engine Rate-of-Climb Speed
to achieve the practise exercise. In turbocharged aircraft
VYSE is designated by the blue radial on the airspeed
there is generally plenty of power available, which means
indicator. VYSE delivers the greatest gain in altitude in
the exercise can be practised at higher altitudes. With non-
the shortest possible time, and is based on the
turbocharged engines, the power availability diminishes
following criteria:
quickly with increasing altitude. Therefore, in order to achieve
»» Critical engine inoperative, and its propeller in
the minimum drag position.
Vmca »» Operating engine at no more than maximum
continuous power.
Stall first
»» Landing gear retracted.
Single engine »» Wing flap in the most favourable position
power-on (best lift/drag ratio).
stall speed
»» Cowl flap as required for engine cooling.
»» Aircraft flown at recommended bank angle.
Pressure altitude
Recovery may be difficult Drag, caused by a windmilling propeller, extended landing
gear, or flap in the landing position, will severely degrade
or destroy single-engine climb performance. Single-engine
Yaw climb performance varies widely with type of aeroplane,
first weight, temperature, altitude and aeroplane configuration.
The rate of climb may be marginal – or even negative – under
Indicated airspeed
some conditions. Study the Flight Manual for your specific
aeroplane and know what performance to expect with one
Figure 5. Relationship between stall speed and VMCA (non-turbocharged engine inoperative (OEI).
engines).
6 vector September / October 2009
It is important to remember that the figures in the Flight
Manual cannot be guaranteed. These figures were established
in a brand-new aeroplane and in the hands of a test pilot – you
may well be unable to reproduce the stated performance.
In many light-twin aircraft, there may not be any single-engine
climb performance. Don’t bet your life on the book figures.
VXSE – Best Single-Engine Angle-of-Climb Speed
VXSE is used only to clear obstructions during initial climb-out,
as it gives the greatest altitude gain per unit of horizontal
distance. It provides less engine cooling and requires more
rudder than VYSE. Some manufacturers do not quote a VXSE,
as performance is marginal – and rarely better than at VYSE.
V1 – Decision Speed
V1 is the maximum speed, for a given length of runway,
from which a particular aircraft could be brought to rest in
the remaining length of runway after one engine has failed.
V2 – Takeoff Safety Speed
V2 is the lowest speed above the stall, while in the takeoff
configuration, and following failure of the critical engine,
where a safe margin of control is ensured for the average pilot. It is not advisable to fly at speeds
The safety speed is therefore always higher than the worst
critical speed. Takeoff safety speed is either declared in the approaching VMCA except in training
Flight Manual or is the greater of 1.2 VS or 1.05 VMCA. Takeoff
safety speed does not provide maximum performance.
situations or during flight tests,
where you have a qualified multi-
The next issue of Vector will have an article on the
practical aspects of dealing with an EFATO.
engine flight instructor with you.
Photo: ©istockphoto.com / Jeffrey Zavitski
vector September / October 2009 7
Photo: ©istockphoto.com/ Maciej Noskowski
Which Runway
Are You Going For?
There seems to be some inconsistency in the way we,
as pilots, refer to runways. This is particularly important
at aerodromes where there are parallel runways.
E
ach runway is designated by will be considered normal operations. This would
the aerodrome operator and equally apply at Tauranga, Hamilton, New
published in AIP New Zealand, Plymouth, Gisborne, and Rotorua.
Vol 4 and pilots should use those
Let’s look at a slightly more complicated example
designations.
– Wanganui. There are three parallel runways,
In order to maintain consistency, and to 29L, 29, and 29R. 29L and 29R are the grass
mitigate any human factors related risks, vectors, and 29 is the sealed vector. If you are
the CAA has been asked to clarify its joining for one of the grass vectors you could
position on the correct phraseology to add “grass” to the designator, for example
use when referring to parallel runways. “29L grass”. To ensure consistency through-
out the country, wherever there is a parallel
Let’s look at a simple example – Wanaka.
runway, when joining the sealed runway,
Here there are two parallel runways of
you should say “joining for 29 seal”.
similar length, both designated runway
29. If you are joining for Wanaka, you Now let’s look at the exceptions.
should be absolutely clear as to which Take Queenstown for example. If you
runway you intend to land on. When are flying a large aircraft intending
joining for 29 you should say “joining to land on runway 23, there will
for 29 seal”, or “joining for 29 grass”. be absolutely no need to request
Other examples of this are Woodbourne, “23 seal”. However, if you are a light
Timaru, Motueka, Kaikoura, Hastings, aircraft, you need to be completely
and Dargaville. clear, so the controller is also clear,
which vector you intend to land
Let’s look at another example – Napier.
on. You should request either
This aerodrome is slightly more critical,
“23 grass”, or “23 seal”. The
as the grass vector crosses taxiways,
same would apply at Christ-
and there is a mix of light aircraft and
church and Invercargill.
turboprop airliners. On initial contact
with Napier, Tower or traffic, inform Hopefully, this has cleared
them of your intentions, for example up any confusion. If in
“34 grass” or “34 seal”. The exception doubt, add either “grass”
would be, however, those airlines that or “seal” and then it will
always use the seal. They do not need be completely unam-
to specify the seal to the Tower – that biguous.
8 vector September / October 2009
Dipsticks
The fuel dipstick is a very
reliable way to measure
the amount of fuel in your
aircraft tanks, but it is often
a misunderstood tool.
T
wo long-standing problems have been identified in Unusable Fuel
relation to dipsticks and usable/unusable fuel: there
The quantity of unusable fuel is determined
are no set standards for dipsticks, and there can be
during the original aircraft certification
variations in the way engineers take account of unusable
process. Usually, this involves a test to find
fuel in calculating empty weight.
out how much fuel remains in the tanks at
A look around the GA fleet at any aerodrome is most likely the point at which the engine fuel supply is
to reveal a variety of home-made dipsticks, calibrated in interrupted. Federal Aviation Regulation
different ways. It is rare to find a dipstick made by the 23.959(a) says that the unusable fuel supply
manufacturer for a particular aircraft. for each tank must be established as not
less than the quantity at which the first
Here are some points regarded as best practice for dipsticks:
evidence of malfunctioning occurs under
»» Dipsticks should be made up by licensed engineers the most adverse fuel feed condition
»» The dipstick should be specific to a particular aircraft, occurring under each intended operation
and have the registration letters on it and flight manoeuvre. For conventional
aircraft with a forward mounted engine,
»» It should be made of a non-absorbent material that will this is usually nose up at best angle of
show the fuel level climb attitude.
»» It should not be able to fall into the tank (usually achieved
The amount of unusable fuel can vary
with length, or a T-cross)
considerably from aircraft to aircraft.
»» The zero calibration should be the point where usable There is a big difference between Piper
fuel starts and Cessna aircraft, for example.
»» It should be calibrated in litres. The Flight Manual should show the
If using an existing dipstick, you must know if it is reading unusable fuel quantity.
usable fuel (recommended) or total fuel. If it reads total fuel,
you will need to know the aircraft’s unusable fuel quantity.
This can be found in the Flight Manual.
Continued over »
Usable Fuel
Usable fuel is the quantity of fuel available for flight planning
purposes – it is the only figure that should be used when
calculating fuel endurance. If the dipstick indicates total tank
quantity you must subtract the unusable fuel quantity to arrive
at usable fuel for calculating endurance.
Some aircraft have a placard showing the usable fuel quantity
near the filler cap.
vector September / October 2009 9
» Continued from previous page
Aircraft Empty Weight
Empty weight is the weight of an aircraft, including airframe,
powerplant(s), all fixed equipment, full oil tank(s), and unusable
fuel. The empty weight figure is found in the form CAA2173
Usable fuel
located in the Flight Manual and can be expressed in Unusable
fuel quantity
pounds or kilograms. On the back of the form is listed all
as stated in
the equipment fitted at the time the aircraft was weighed. the Flight
Manual
Engineers preparing the CAA2173 form need to adhere to the
manufacturers’ procedure for determining unusable fuel. This Fuel outlet
port
varies from type to type. For example, some manufacturers To engine
Un-drainable fuel
will use a method that runs the engine until it stops, and then
Fuel drain point
add a specified quantity, whereas other manufacturers may
say to drain the tanks entirely, and add a specified amount. Cross-section of an aircraft fuel tank (not to scale)
The resulting level may be above the fuel outlet port to allow
for the manoeuvres described above (see diagram).
»» Fuel tanks should always be dipped after refuelling to
For more information see our booklet, Weight and Balance, establish the exact amount of fuel on board – even when
and Advisory Circular AC43-2 Aircraft weight and balance adding a known quantity of fuel.
control – forms CAA2102 and CAA2173. »» The dipstick should be inserted in the filler neck perpen-
dicular to the wing surface, unless there is another method
Role of the Fuel Gauges specified in the Flight Manual. Some aircraft fuel tanks
Contrary to some opinion, most fuel gauges do read reason- must be dipped on an angle because the main spar is
ably accurately. After dipping the tanks, check the gauges and directly below the filler neck.
compare the readings – you will then know if the gauges »» Always take a fuel sample from each drain point after
are reading accurately. If they don’t, they need to be repaired. refuelling, to check for correct fuel grade and any impurities.
The fuel gauges should be an integral part of your fuel For more information, see our booklet Fuel Management.
management. Monitor levels during flight, and compare with You can get a free copy by emailing info@caa.govt.nz.
your calculations. Fuel loss in flight can happen – through fuel
venting, for instance, or a leaking fuel drain. This may not be
visible, especially in a low-wing aircraft, so the fuel gauges
may be your only clue that fuel is being used at a greater rate
than planned.
Tips for Dipping Your Tanks
Here are some points that should be kept in mind when
dipping a fuel tank:
»» The aircraft should be parked on level ground. If this is
not possible, dip each tank, turn the aircraft through 180
degrees, dip each tank again, and take the average of the
two values. This may not be totally accurate, but it will be
better than either of the two single readings.
»» Cross-feeding during refuelling, or at any other time, can be
prevented in most single-engine aircraft by selecting either
the LEFT or RIGHT tank only. The trap here is that when
you are refuelling the aircraft with the fuel selector
set to BOTH, the tank that you are filling can be
cross-feeding to the other tank. Although not large,
this could result in a quantity of fuel less than was
originally intended in the first tank by the time you have
finishing filling the second tank, and this could be a
problem if the flight requires both tanks to be full.
10 vector September / October 2009Contaminated Fuel
Contaminants (especially water) in Allow the fuel time to settle after
fuel have been known to cause engine doing this before taking a fuel
failures – usually just after the aircraft sample.
has become airborne. There have
»» Ensure that the drain vessel is clean
been instances when fuel from jerry
before taking a sample. Hold the
cans that had been contaminated
sample to the light and inspect it for
with water was used in aircraft
water (normally indicated by small
operations, with disastrous results.
globules sitting on the bottom, or a
The pilots involved were simply
‘cloudy’ appearance), and sediment.
unable to tell by looking at the sample
Check that it is the correct colour
that the fuel was contaminated.
and smell for the intended grade of
Here are some tips to check for fuel – this will also confirm that you
contaminants in fuels: have not just drained a sample of
»» After refuelling, allow the fuel to pure water.
settle for as long as possible. This »» If the sample is contaminated, empty
gives any impurities a chance to the vessel and continue draining until
settle into the drain sump of each a clean sample is obtained. Fuel tester, showing
water that has
tank. At an intermediate stop, it is a settled at the bottom
»» Do not tip the sample back into
good idea to refuel the aircraft first, (holding it against
the aircraft tank, even if it is clean – the white surface
before attending to other business
dispose of it in an appropriate helps to show the
– this will normally allow enough fuel colour and any
manner.
time for any water in suspension to water present).
settle out. »» If there are unusually large quantities
of water present in the fuel, consult
»» Water often collects in wrinkles and
an aircraft engineer.
low points within fuel bladders.
Lateral shaking of the aircraft wing »» In cold winter conditions, small
will help to work any trapped water amounts of water can freeze the
down to the fuel drain sumps. drain plug, rendering it inoperative.
Flight Instructor Jonathan McKay of the
Wellington Aero Club looks at the fuel
readings on the aircraft’s dipstick.
vector September / October 2009 11Prop Strikes
Engine and propeller manufacturers are quite clear about what constitutes a
prop strike and what maintenance is then required.
T
extron Lycoming defines a prop strike in its Service
Bulletin 533A as, “Any incident during engine operation
in which the propeller impacts a solid object which
causes a drop in RPM and also requires structural repair of the
propeller (incidents requiring only paint touch up are not
included). This is not restricted to propeller strikes against
the ground, and although the propeller may continue to rotate,
damage to the engine may result, possibly progressing to
engine failure.
A bent propeller that can be repaired.
“Textron Lycoming must take the position that in the case of a
... propeller/rotor strike ... the safest procedure is to remove
and disassemble the engine and completely inspect the
reciprocating and rotating parts including crankshaft gear and
dowel parts. Any decision to operate an engine which was
involved in a ... propeller/rotor strike ... without such an
inspection must be the responsibility of the agency returning
the aircraft to service.”
Therein lies the heart of the matter. As an engineer you are
responsible for returning the aircraft to service. If you do not
get the inspection done, what acceptable data are you basing Cracking of the crankshaft after impact damage, shown up by fluorescent
the return to service decision on? light during magnetic particle crack testing.
Even if no drop in engine rpm was seen – it’s unlikely the pilot’s If the fear of the cost is making your aircraft owner nervous,
attention was on the rpm gauge when hearing loud crunching they need to realise that this cost is usually covered by the
noises from the propeller – there could still be significant insurance policy, and the cost of not doing it may be much
damage to the engine. higher if they suffer an in-flight engine failure.
Alan Hockey of Flightline Aviation Dunedin says, “There The inspection of the engine must be carried out by an
doesn’t seem to be any pattern to the damage to the engine appropriately approved Part 145 Maintenance Organisation
when compared to the damage the prop has sustained. I have and includes a complete dismantling of the engine, inspection
seen propellers that seem to have minor damage, but of all rotating components and engine-driven accessories,
the engine attached to them has a broken crank-shaft. Like the replacement of particular parts (such as connecting rods
aircraft that hit a hidden airfield marker board.” and nuts, and anything specified in the Replacement of
The Prop Shop at Safe Air stresses that you Mandatory Parts Bulletin) and probably some non-
cannot just straighten the prop out and destructive testing.
continue on flying. You have no idea Propeller testing and overhaul must be
what damage has been done without completed by an approved maintenance
a proper inspection. provider.
Bends are measured in degrees over a two inch
length using a protractor.
12 vector September / October 2009CAA to Relocate
in Central Wellington
The CAA is to relocate from Petone, Lower Hutt to central Wellington in
February 2011.
I
t will occupy one-and-a-half floors Director of Civil Aviation Steve Douglas that we will move to is modern in design,
of a commercial office block, still says the process was thorough and all with good energy efficiency design
under construction, directly opposite options were carefully examined. characteristics. Our people will have a
Wellington’s Railway Station. The only good working environment, and be
“The CAA’s Board has been fully
other tenants in the 15-storey building located close to public transport.
involved since the project began in
will be the Inland Revenue Department “And as those who have a longer history
2007. The relocation and the funding
and the Aviation Security Service. with the CAA will remember, this will be a
arrangements were approved by
The CAA currently occupies two the Board with the support of the return to central Wellington for the CAA.
The organisation moved from central
buildings in Petone, of which one is a Government in 2008.”
Wellington to Lower Hutt in 1988.”
converted warehouse. Neither is suitable
The CAA has conservatively estimated
for the CAA’s long-term requirements.
the one-off costs of the move will be
The expiry of the lease on the two $6.7 million, and will be funded from the
ay
buildings provided an opportunity to CAA’s reserves and cash flow. Beehive ton
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consider relocation and the CAA started
Steve Douglas says the move to
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advice to evaluate the relocation ay
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that is in the long-term interests of the Qu
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requirements in the next 15 to 20 years, “We set about finding office space that yS
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to the aviation industry and closer to from industry, and to meet our current
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other transport sector agencies. and future requirements. The building
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vector September / October 2009 13Taildraggers 101
You take off, accompanied by friends and a picnic basket full of delectable
treats. You fly over some of New Zealand’s most incredible scenery, and
land on a remote strip. You while away the afternoon in a beautiful spot.
Then the alarm clock goes off…
W
hy not make this dream a reality by learning to fly a taildragger? Figure 1. Directional instability of a taildragger.
The short-field performance and prop clearance of many taildragger
types make them a logical choice (but not the only choice) if you are
interested in strip flying.
Aircraft momentum
Here are a few basics to get your head around before your first lesson.
On the Ground
Taxiing successfully requires your full attention at all times. In addition to using
your feet quickly and purposefully, instructor Paul MacDonald tells students
transitioning from flying a nose wheel aeroplane, to the C185, “Don’t be afraid
to use power and brake at times, always position your ailerons in the correct
sense for the wind direction, and catch things early.”
Taildraggers act as a weather vane, and turn into wind naturally. A turn in that
direction is simple, but turning downwind can be very hard. In strong winds
you will need appropriate use of rudder, brake, and power. Power will increase
the air flow across the rudder, making it more effective. Main wheels
Watch the nose direction at all times and concentrate on keeping it straight.
Anticipate any movement of the nose and use positive rudder inputs to control it.
It is important to be proactive, because once a taildragger starts to turn, they
CG
tend to continue turning. This characteristic is related to the C of G position.
A taildragger’s C of G is behind the main gear, to stop it tipping on its nose.
If a taildragger taxis in a straight line and then turns left (as in Figure 1), the
C of G becomes positioned behind the right main wheel. Due to momentum,
the C of G continues moving along its original path, which is straight ahead.
This continues the turn by pushing against the outside wheel.
When you press the rudder pedal in a taildragger, there will be a slight delay Tail wheel
between applying the pressure and seeing movement. Once the nose is moving,
it will continue to move whether the pedal is pressed or not, so rudder is only
used to initiate movements, not held in while turning. You will then need to
14 vector September / October 2009Figure 2. Lift forces on takeoff.
Lift Forces on Takeoff
In Figure 2, you will see that the horizontal tail surfaces on the
trike produce a downward force to raise the nosewheel. This
‘negative lift’ effectively adds weight to the aeroplane and requires
the wing to produce additional lift for takeoff. By comparison,
the horizontal tail surfaces on a taildragger produce an upward
force (positive lift) to raise the tail. Since the tailplane supports
some aircraft weight, the wing does not have to produce as much
additional lift to get the aeroplane off the ground.
Takeoff techniques vary between types and between instructors.
Many higher performance aeroplanes (such as the Pitts Special)
start the takeoff roll with the stick hard back until there is plenty of
airflow over the rudder, then raise the tail. Whereas some slower
taildraggers begin the takeoff roll with the stick hard forward so
Lift forces of the tail surfaces in nosewheel vs tailwheel aircraft. the tail comes up as soon as it has enough speed.
In either case, here are a couple of issues to be aware of.
apply rudder with your other foot to stop the nose where you Any time the propeller disc moves its plane of rotation,
want it. The amount of rudder required is inversely proportional gyroscopic forces occur. Raising the tail too abruptly on takeoff
to your speed. The faster you are moving, the less rudder you (by forcefully pushing the stick forward), will cause the propeller
need for directional control. to precess, and the aeroplane to turn left. Always use positive
rudder inputs to keep the aeroplane straight, do not let it start
The degree of difficulty you will have in controlling a taildragger to turn in the first place.
is directly related to your ability to see slight movements of
Raising the tail too high during takeoff will set the wing at a
the nose and correct for them. Tiny movements need tiny
negative angle of attack and drive the main landing gear harder
corrections – let big movements develop and you will need
onto the ground. The increased tyre friction created, along
big corrections, or potentially loose directional control.
with the additional drag produced by such a tail-high attitude,
It will take new taildragger pilots time to get used to the will reduce your acceleration considerably. It can even prevent
restricted visibility over the nose. Slowly S-turning along the some low-powered taildraggers, at a high density altitude,
taxiway will give you the ability to look for other traffic and see from ever reaching liftoff speed.
where you are going. Continued over »
vector September / October 2009 15Photo courtesy of Craig Hayden
» Continued from previous page
Figure 3. Bounce on touchdown.
Angle
of atta Momentum
ck inc
reases
CG
Paul MacDonald explains to his students, “On takeoff, slight would usually require either full forward or back elevator
forward pressure is needed to get the tail up and flying, then pressure, heavy braking, or a combination of these with power.
ease back gently to lift off. Since the Cessna 185 naturally lifts The key to avoiding this is understanding the effects of C of G
off at around 35 or 40 knots, you may need forward pressure position and the wind, taxiing slowly with your controls in the
after liftoff to accelerate to a safe speed – depending on the trim appropriate position, and smoothly applying brake.
setting.” Your instructor will show you what the appropriate
Ground loops after landing are usually caused by losing direc-
takeoff trim settings are for the type of aircraft you are flying. tional control through inattention. They happen when yaw is not
anticipated, and then assertive rudder inputs are not made to
Landing firstly stop the turn continuing, and secondly bring the nose
The key to a successful landing in a taildragger is to touch back parallel with the centerline. When the nose begins to swerve,
down straight, at the appropriate speed and attitude for the unless it is caught, it continues to yaw with a progressively
type of landing you have opted for. shorter turning radius. As the arc made by the aircraft begins to
spiral inward, the rate of turn also increases. Simultaneously,
A bounce is the result of a pilot error; a factor of landing centrifugal force increases, and unless this is interrupted, the
speed and rate of descent. The C of G location in a taildragger aircraft ultimately loses balance and topples toward the outside
(behind the main gear) contributes towards their propensity to wing. Anticipation is essential. If you wait until the nose swerves,
bounce, but a pilot cannot shift the blame for a bounce onto and then try to correct it, it is too late. Paul MacDonald says,
the aircraft design. If the aeroplane is landed in the appropriate “After landing, keep your feet working and steer straight away –
wheeler or three-point attitude, at the appropriate speed, a don’t go to sleep once you are on the ground.”
bounce will not occur.
Ground loops are not that difficult to avoid. Just remember that
The aeroplane in Figure 3 has been allowed to touch down a taildragger landing is not complete until the aircraft is parked –
prematurely, and the tailwheel is still off the ground. If the don’t think your job is done after a successful touchdown.
touchdown occurs with any significant sink rate, the momentum
Learning to fly a taildragger is not necessarily more difficult than
of the C of G tends to push the tail further down. In the process,
learning to fly a trike. They are just less tolerant of errors made
the nose rises, increasing the wing’s angle of attack. As a result,
along the way.
additional lift is produced, causing an involuntary liftoff.
Newton’s third law also applies. For every action there is an Specialist taildragger instructor, Kerry Conner, says, “the
equal and opposite reaction, so the ground ‘pushes back’. challenge of flying a taildragger is controlling and handling it
correctly on the ground.
If the tail wheel touches simultaneously with the main gear,
however, or slightly earlier, the angle of attack cannot be made “When a new taildragger pilot has mastered the three-point
to increase providing the aircraft is virtually stalled when in the landing, and their confidence is building, their concentration
three-point attitude, resulting in a minimal touchdown speed. drops off, they get a wind gust, and bam – they are off the
runway or facing 180 degrees to the landing direction. After
New taildragger pilots often look out the side window as the
this lesson, it is time to move on to wheel landings – no wind
aeroplane settles on the ground. This makes it difficult to judge
at first, to get the technique mastered, and once that is
if you are rolling straight or not. Instead, look straight ahead
under control I take them out in a crosswind. Students start by
and use your peripheral vision to look at both sides of the
learning the three-point crosswind, then a wheel crosswind,
runway at once. This will make minor movements of the nose
which eventually has them landing on one wheel.
easier to detect, and a quicker response possible.
“Once they have mastered the three, two, and one wheel landings
A ‘wheel landing’ can be more difficult to perform. It is executed
on a sealed runway, a new taildragger pilot is ready to fly solo.
in a near-level attitude by literally flying the main wheels onto
the runway. The pilot has better visibility during a wheel landing “Throw in the short landing technique and you can have five or
due to the aircraft attitude, and when it is gusty, a wheel landing six different types of landings with which to test your piloting
allows you to maintain control right down to the runway. skills. Flying a taildragger is a test of a pilot’s situational aware-
ness of wind when determining landing type, making the
In most taildraggers, it is possible to nose over during touch-
correct decision, and being able to execute the chosen landing
down, but flying a stable approach profile, using the correct
while keeping both pride and aircraft intact,” says Kerry.
technique for the landing type, maintaining speed control, and
immediate directional control, will avoid this. It is also possible If you do take up the challenge, make sure you learn with an
to nose over when taxiing with a tailwind, or turning – but this instructor who is experienced on type.
16 vector September / October 2009Flight Instructor Seminars
The recent flight instructor seminars held in Masterton, Hamilton, and Ashburton were a great success,
with approximately 130 instructors attending. The prime objectives were to give instructors the
opportunity to network and to give them direct access to CAA expertise.
“We deliberately hold the seminars affects your student’s attitude and Day one was finished off by Rachel
away from the main centres because perception of flying. Donald giving a presentation on Spider-
it’s important for them to get together tracks – the New Zealand developed
Mark Price, CAA Examiner AME and
and find out that they have the same flight following technology.
very experienced maintenance engineer,
problems as each other. It can feel pretty
emphasised that as pilot-in-command Day two started with Dr Claude Preitner,
isolated, working away in a small aero
you are the final decision maker when CAA Senior Medical Officer, and pilot,
club on your own, and we want to send
it comes to determining if the aircraft is talking on life changes, particularly the
the message that instructing counts,”
airworthy. He then talked about what aging process, and the Recreational
says John Parker, CAA Flight Examiner.
is airworthy and what is not. Pilot Licence.
This year’s theme was changes – what
John Parker, organiser of this event, The rest of the day was an instructional
changes have recently occurred, what is
spoke about threat and error manage- techniques refresher by Kaye Sutherland
coming up, and how to deal with change.
ment. He encouraged instructors to of Air New Zealand.
Day one saw Rex Kenny, CAA Manager become familiar with this approach, as
Sport and Recreation and prolific Jeremy Anderson of Nelson Aviation
they will see more of this in general
amateur aircraft constructor, give a College says, “I enjoyed it immensely.
aviation, not just in the airlines.
presentation on the future use of Light It was the first time I have been, but I
Sport Aircraft for flight instruction. Airways gave a presentation on radar am really keen to get to the next one.
air traffic control, using a radar screen Probably the best thing about the
ASL gave a presentation on the changes replay to show how air traffic controllers seminar was the ability to talk to other
to examinations, particularly the intro- maintain separation and traffic flow in a instructors and to the CAA directly. Now
duction of computer-based exams. busy radar environment. that doesn’t mean that the sessions
Peter Wheeler, CTC Aviation Hamilton, weren’t good – they were, some of them
Carlton Campbell, CAA Training
gave a presentation on the changing were great, especially the ones on air-
Photo courtesy of Cessna Aircraft Company
Standards Development Officer, A-Cat,
face of avionics and new GPS worthiness and your job as an instructor,
and experienced mountain flyer, gave a
technologies available in GA aircraft. and the one from the doctor.”
heads up on the terrain and weather
There is some very high-tech gear
training being introduced into the PPL Steve McNabb, of Helipro in Paraparaumu
available for light aircraft.
and CPL syllabuses, and how that added, “I thoroughly enjoyed it, and I
Brendan Bourne, CAA Aviation Examiner training is being rolled out. He also didn’t really expect to. The networking
and experienced A-Cat, talked about alerted instructors to the current was important, but for me, I really
the responsibilities you take on as development by the CAA of a new enjoyed the stuff on Spidertracks,
an instructor. How your attitude and mountain flying DVD, and the topic of mountain flying, and the instructional
professionalism, especially as a C-Cat next year’s AvKiwi Safety Seminars. techniques refresher.”
vector September / October 2009 17Airspace Changes
This year’s round of airspace changes will come into effect 19 November 2009,
to coincide with new Visual Navigation Charts. Here is a summary of the main
changes. It is not exhaustive – pilots should familiarise themselves with all
the changes published in AIP Supplements 134/09, 135/09 and 136/09.
T
here are two main outcomes from the safe and efficient flow of VFR traffic. The second outcome is an increased
the 2009 airspace review process. This will reduce the number of circuitous number of Common Frequency Zones
VFR aircraft will have increased tracks flown to avoid controlled air- (CFZs). CFZs are designed to improve
access to portions of controlled air- space, and also reduce controller safety by establishing a single frequency
space, either by the establishment of workload. Always operate your trans- to assist collision avoidance, and reduce
VFR transit lanes, or by the removal ponder on mode A and C, to provide congestion on 119.1 MHz. Use of the
of controlled airspace entirely. Where added safety assurance when operating CFZ frequency is not mandatory.
controlled airspace is not used by IFR near controlled airspace boundaries,
aircraft, it has been released to improve especially within VFR transit lanes.
Hamilton
OLD NEW
WOODBOURNE
OLD NEW
18 vector September / October 2009Auckland
The collision avoidance frequency for
Wellington
The Paraparaumu MBZ has
AIXM Database
aircraft transiting between the Auckland been extended offshore,
The CAA provides an Aeronautical Infor-
City MBZ and the Ardmore MBZ has been while onshore portions of the
mation Service (AIS) comprising the AIP
clarified with the establishment of a new MBZ have been reduced. The
New Zealand, aeronautical charts, NOTAM
Ardmore CFZ using 118.1 MHz. Adjacent MBZ will become transponder
and pre-flight briefing services. Airways
MBZ and CFZ boundaries have been mandatory from 1500 feet amsl
Corporation are contracted to provide
adjusted in accordance with feedback and above. To the East of the
this service. The CAA also provides
from airspace users. MBZ, a new Tararua CFZ has been
a legal description of airspace,
A new Coromandel CFZ has been established on the same frequency
as Paraparaumu. and the geographical coordinates
established between the Great Barrier, of designated points and other
Ardmore and Bay of Plenty areas. As Within the Wellington control zone, significant locations contained in
a consequence, the following aero- new sectors have been established to the New Zealand Air Navigation
dromes will change to 124.5 MHz on allow safer transit of VFR aircraft
Register (ANR).
19 November 2009: Coromandel, Great above the new wind turbines west of
Mercury, Matarangi, Pauanui Beach, Wellington. The data for the various AIS prod-
Thames, Waihi Beach, and Whitianga. ucts and the ANR resides in
many separate databases. Currently,
Tasman
Waikato The Nelson VFR transit lanes have
human processing is involved at
several key stages of AIS production.
Two new VFR transit lanes have been been expanded and merged. The MBZ
Information is submitted for the
established within the Hamilton control at Motueka has been enlarged at user
AIP in paper format, then manually
zone. The Northern VFR transit lane request, and a new Motueka CFZ has
processed to produce a paper
(NZT 251) will allow aircraft operating by been established adjacent to the MBZ,
day to transit from the north to the east, format AIP New Zealand. All users
on the same frequency.
below 1000 feet amsl, without the need manually enter the data into their
Woodbourne airspace has had major systems, and the CAA manually
to contact ATC. Even though the transit
changes to allow VFR aircraft to updates the ANR.
lanes have been designed to be well clear
operate to and from Omaka aero-
of IFR procedures, pilots need to carefully This is in the process of changing.
drome, by day, without an ATC
identify the new transit lane boundaries The CAA and Airways are devel-
clearance. This will significantly reduce
so they do not infringe controlled airspace. oping an Aeronautical Information
Woodbourne Tower’s workload. How-
The landscape within the transit lane eXchange Model (AIXM) database
ever, as Omaka is very close to the
has relatively few prominent features. to serve as the single source of
extended centreline for Woodbourne
To assist pilots, a railway/road intersection national aeronautical information.
Aerodrome’s runways, it is essential
and major roads have been used as the This move is in line with develop-
transit lane boundaries. that Omaka traffic respect and comply
with the strict limits of the new ments in the rest of the world, and
The Northern VFR transit lane has also Omaka VFR transit lane. The Waihopai will use an ICAO recognised format
been merged with the Hospital VFR and Ponds VFR transit lanes will be to reduce the need to manually
transit lane to allow helicopters to freely disestablished as a result. manipulate data. Once all aerodrome,
arrive and depart from the Hospital heliport, airspace, navaid, obstruction,
Heliport by day. Fixed wing pilots should Within the Omaka VFR transit lane, instrument procedure, route, and
note that the rule 91.311 requirement to pilots must not cross New Renwick
significant point data has been
maintain 1000 feet above built up areas Road unless they receive an ATC
entered into the database, and
means it is not possible for them to use clearance to do so (this road was
verified, it can then be transferred
the portion of the VFR transit lane above the northern boundary of the
electronically to users.
Hamilton City. disestablished Fairhall Sector).
Benefits:
The new Te Awamutu VFR transit lane to To the south and west of
Woodbourne, a large portion of »» A single source database for aero-
the south will allow VFR aircraft to operate
control area (CTA) has been nautical data.
freely south of Lake Ngaroto, below 1000
feet amsl, by day. disestablished in order to allow » Paper based products will be
gliding operations to take place generated directly from the AIXM data
Taupo in class G airspace in this area. with minimum manual intervention.
At the request of airspace users, the » Aeronautical data will be available to
Taupo MBZ has been extended to the Canterbury the aviation community in an electronic
east. The transponder mandatory portion A new Rangiora CFZ has been format.
of the MBZ has been lowered to 2500 established, so the frequency
The AIXM is currently being populated with
feet amsl. The Centennial Park CFZ has of Rangiora Aerodrome will
existing data. Over the next two years the
been also extended and its upper limit change to 120.2 MHz. The
AIP New Zeland and the ANR will begin to be
raised to 4500 feet amsl to better reflect Canterbury CFZ has had
produced out of the AIXM database, going
the normal operating area of gliders near a consequential boundary
‘live’ once the products are fully tested.
Centennial Park Aerodrome. amendment.
vector September / October 2009 19Competently Current
Unless you are employed as a pilot it can be hard to stay current – and even
then you may need a top-up from time to time. Current shouldn’t just mean
legally current, it should mean competently current.
T
he bare minimum required to be legally current is far You are the best person to be able to judge if you are current
from ideal, and it could leave you floundering in an enough to do a particular flight or task. To allow for things
unexpected or emergency situation. you hadn’t planned on, you must be prepared to a higher
standard than may prove necessary on any particular flight.
In flying, as in any other endeavour in life, the rewards and
satisfaction achieved are proportional to the effort put in.
Are you happy to be a ‘bare minimum’ pilot, or would you How to Improve Currency
rather be thought of as a careful and competent pilot others
In Your Aircraft
are happy to go flying with.
Decide what flying you really need. Money seems to have
stopped growing on trees, so tailor your flying to best prepare
Currency you for the type of flying you do.
You progressively lose your touch the longer you go without
If you are an infrequent flyer, collecting type ratings
flying. The longer the break, the less current, competent,
may be fun, but is it the safest option for
and confident you become.
maintaining an adequate currency level?
There are legal minimum requirements to be able to Sticking to one type may help you feel
exercise the privileges of your licence, including recent more confident, and your flying will be
experience requirements. But these may not be enough to safer and enjoyable.
be truly current.
Currency is not just the number of flying
hours and takeoffs and landings you
have completed in the last 90 days –
it’s a measure of your readiness
to undertake a particular exercise
without significant risk.
20 vector September / October 2009You can also read
