Ultimate-Jets

Maiden and Test flight program

This is an article written from my 20 year experience in flight testing airliners and industrial/ military UAV.

This article in now way is trying to explain how to flight test the above vehicles, but rather is an adaptation of the core philosophy to the hobby/ UAV world.

This is a rather slow and resource intensive method but it is quite essential to the designer who puts a new airframe in the air. The procedure below will also be useful to the professional modeler who wants to flight test a very complex scale model.

The flight phase must be started after the pre-flight tests have been completed. All the snags discovered during the previous phase must be cleared before the flight test phase.

The core philosophy of a flight test program is to progressively open up the flight envelope.

It starts from low speed, flaps extended, gear extended to progressively retracting the drag elements and increase the speed. The test program is completed when top speed has been validated as well as all the high G maneuvers intended for the plane. CG position in all configuration must also be validated. For this purpose, a digital balancing equipment is a vital tool.

For all of this, 2 spotters are recommended. One program spotter who will announce the next program maneuvers announce the stall speeds, max speed, configuration changes, compute 1.3 Vs etc , one flight spotter who will check the airspace and possible conflicts and give feedback on the airplane behavior ( nose attitude, CG behavior etc ).

An additional camera operator is also recommended to capture every flight.

A full telemetry system with ground return is recommended to get a feedback of the flight speeds as well as model parameters like remote link quality, battery voltages...

 The typical flight test program is described below:

 

Taxi tests:

Configuration: fixed, gear down takeoff flaps.

Program: 

Low speed taxi, validate the steering effectiveness.

High speed taxi, validate the steering effectiveness

Rejected takeoff medium speed: validate the brakes effectiveness

Rejected takeoff high speed: validate elevator effectiveness by pulling near Vr. The nose should start to lift.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ).

 

Flight 1, configuration stalls and approach speed validation: 

Configuration: semi fixed, gear down takeoff flaps then landing flaps.

Program: 

Takeoff,

One to two patterns for trimming with takeoff flaps. Check CG behavior in turns ( how much up elevator ? ). Check the controls throw and adjust if required ( via dual rate ).

Extend landing flaps.

One to two patterns  for trimming with landing flaps. Check CG behavior in turns  how much up elevator ? ). Check the controls throw and adjust if required ( via dual rate ).

Climb and stall at comfortable altitude. Record stall speed, implement 1.3 vs that is the approach speed ( spotter's job ).

Come back for landing. Approach at 1.3 Vs.

Landing and full stop.

This flight takes typically 4 to 5 minutes.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ) internal components fastening, servos fastening, servo arm, pushrod, control horn, fuel system, flight controls slop, gear slop, bearing and gear pin slop.

Make a snag list and clear it at the workshop. Wait one week before flight 2 and review all the flight parameters and data. Briefing with the spotters. Modify the dual rate/ control throws if required. Modify the CG if required.

 

Flight 2, CG validation/ fine tuning: 

Make this flight when the previous snag list is clear.

Configuration: semi fixed, gear down takeoff flaps then landing flaps.

Program: 

Takeoff,

One pattern to confirm trimming with takeoff flaps.

One pattern to confirm the new CG behavior further ( if changed ).

Extend landing flaps.

One pattern to confirm trimming with takeoff flaps.

One pattern to confirm the new CG behavior further ( if changed ).

Climb and stall at comfortable altitude. Record stall speed, implement 1.3 vs that is the approach speed ( spotter's job ) with the new CG position.

Come back for landing.

Landing and full stop.

This flight takes typically 4 to 5 minutes.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ) internal components fastening, servos fastening, servo arm, pushrod, control horn, fuel system, flight controls slop, gear slop, bearing and gear pin slop.

Make a snag list and clear it at the workshop. Wait one week before flight 3 and review all the flight parameters and data. Briefing with the spotters.Modify the dual rate/ control throws if required. Modify the CG if required.

 

Flight 3, gear retraction and stall speeds: 

Make this flight when the previous snag list is clear.

Configuration: variable, gear down then up, takeoff flaps then landing flaps.

Program: 

Takeoff,

One pattern to retract the gear in front of you

One pattern to confirm the new CG behavior with gear up.

Extend landing flaps.

One pattern to confirm the new CG behavior with gear up.

Climb and stall at comfortable altitude. Record stall speed, implement 1.3 vs that is the approach speed ( spotter's job ) with the gear up.

Come back for landing.

Extend the gear.

Landing and full stop.

This flight takes typically 4 to 5 minutes.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ) internal components fastening, servos fastening, servo arm, pushrod, control horn, fuel system, flight controls slop, gear slop, bearing and gear pin slop.

Make a snag list and clear it at the workshop. Wait one week before flight 4 and review all the flight parameters and data. Briefing with the spotters. Modify the dual rate/ control throws if required. Modify the CG if required.

 

Flight 4, flaps retraction and stall speed ( do not push the speed ): 

Configuration: variable, gear down then up, takeoff flaps then clean, then landing flaps.

Make this flight when the previous snag list is clear.

Program: 

Takeoff,

One pattern to retract the gear in front of you

One to two patterns to retract the flaps and trim.

One to two patterns to check CG behavior.

Climb and stall at comfortable altitude. Record stall speed, implement 1.3 vs that is the stall  speed protection ( spotter's job ) with flaps up.

Come back for landing.

Extend gear and landing flaps.

Landing and full stop.

This flight takes typically 5 to 6 minutes.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ) internal components fastening, servos fastening, servo arm, pushrod, control horn, fuel system, flight controls slop, gear slop, bearing and gear pin slop.

Make a snag list and clear it at the workshop. Wait one week before flight 5 and review all the flight parameters and data. Briefing with the spotters. Modify the dual rate/ control throws if required. Modify the CG if required.

 

 

Flight 5, flap up CG validation with inverted flight ( do not push the speed ): 

Configuration: variable, gear down then up, takeoff flaps then clean, then landing flaps.

Make this flight when the previous snag list is clear.

Program: 

Takeoff,

One pattern to retract the gear in front of you

One to two patterns to retract the flaps and trim.

One to two patterns to check CG behavior:

Climb at 45 degrees and invert the plane. Once the plane is climbing stable on its back, release the elevator pushing action. Let the plane fly alone. Note the behavior. If the nose is dropping heavily: too nose heavy. If the plane is dropping the nose slightly: good CG. If the plane is climbing more ( nose going up ): too aft CG.

Come back for landing.

Extend gear and landing flaps.

Landing and full stop.

This flight takes typically 5 to 6 minutes.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ) internal components fastening, servos fastening, servo arm, pushrod, control horn, fuel system, flight controls slop, gear slop, bearing and gear pin slop.

Make a snag list and clear it at the workshop. Wait one week before flight 6 and review all the flight parameters and data. Briefing with the spotters. Modify the dual rate/ control throws if required. Modify the CG if required.

 

Flight 6, flap up CG validation with inverted flight ( do not push the speed ): 

Configuration: variable, gear down then up, takeoff flaps then clean, then landing flaps.

Make this flight when the previous snag list is clear.

Program: 

Takeoff,

One pattern to retract the gear in front of you

One to two patterns to retract the flaps and trim.

Two patterns to check the new CG behavior:

Climb at 45 degrees and invert the plane. Once the plane is climbing stable on its back, release the elevator pushing action. Let the plane fly alone. Note the behavior. 

If the CG is good, come back for an inverted flight in front of you ( if the airframe permits it ). Note how much elevator stick pushing is required. 

Come back for landing.

Extend gear and landing flaps.

Landing and full stop.

This flight takes typically 5 to 6 minutes.

Post flight verifications: Steering servo, brakes wear, tire wear, gear components, turbine parameters, battery consumption, fuel consumption, air trap air quantity ( should be full ) internal components fastening, servos fastening, servo arm, pushrod, control horn, fuel system, flight controls slop, gear slop, bearing and gear pin slop.

Make a snag list and clear it at the workshop. Wait one week before flight 7 and review all the flight parameters and data. Briefing with the spotters. Modify the dual rate/ control throws if required. Modify the CG if required: if too much pushing is required when inverted, get the CG aft. If to light on the stick push, get the CG forward.

 

Repeat flight 7 program till the CG is set to your preference.

 

Subsequent flights:

Gradually push the speed to the maximum allowed speed and check the airframe.

Start introducing aerobatic maneuvers if the plane is capable of it. Start with low G's maneuvers ( rolls ) then high g's maneuvers ( loop based maneuvers ).

The last maneuver to perform will be the snap stall if the airframe is capable of it.

Verify: no signs of flutter, no cracks on the spars, skin, control horns...

Once the test program is fully completed, the plane can be flow with confidence in meetings and competitions. Note that the airframe will gradually age and once the early failure rate is eliminated, will slowly get more reliable.

Written by Olivier Nicolas — September 17, 2016

Pre-flight procedures and testing

1.    Introduction

One thing that I have learned after 20 years of building and flying all kinds of jets is that a proper testing routine of all the aircraft systems prior to the maiden will save you from lots of possible problems and crashes.

You can decide to go straight ahead and maiden your latest beauty fresh from the workshop. But this would mean that you’d actually test the aircraft components and systems in real flight conditions.

Or you can decide to follow a complete test routine and try to troubleshoot as many things as possible before the maiden, in conditions set as close to the flight environment as possible. The advantage of this approach being the following:

  • You will be able to anticipate the problems in the workshop with plenty of time to correct them.
  • You will be able to test the systems and get rid of the early failures or “infant mortality” as called in the aeronautical jargon. The idea is to position your systems in the constant failure rate area ( or highest reliability zone ) of the bathtub curve before the maiden.

 

I have detailed the complete routine that I follow before any maiden below. This might look long and constraining but I believe that it is worth the effort considering a plane that sometimes costs over 10 000 USD and is essential to certify professional UAVs..

Of course and depending on your confidence about your building capability and material reliability you could skip any of the following steps.

2.    Electrical system test

 

The electrical system test is quite important to my eyes for the following reasons:

  • You will eliminate the possibility of an early component failure
  • You will eliminate the possibility of a servo binding
  • You will be able to characterize your system’s power capability, current consumption and electrical endurance and use it for characterizing the state of your electrical system when it gets older via our statistical log reader.
  • You will discard the possibility of a regulator thermal runaway or receiver thermal lock ( Futaba FASST )

2.1. Individual component test

 

I check that the servos are operative at an early stage when fitting them in the plane. I just use a small servo tester like the Astro Flight servo tester and move the arm to each end of travel. I also use this device to center the servo hub before fitting the servo arm.

I then test again the servo when the control surface linkage and associated electrical loom is completely setup. I plug the very useful Hangar9 digital amp meter between the receiver and the loom. I test the servo from the radio in all the directions at a slow pace and make a note of the current reading. This will be useful for two reasons:

  • To setup a basic consumption value at “age 0” that will be used to monitor the servo ageing.
  • To check that there is no flight control binding or wiring problem ( bad cable, intermittent plug contact… )

An elevator servo readout at idle

 

Same elevator servo readout in motion

 

 

2.2. Torture test

 

When all the servos have been successfully tested and the electrical system is completed, I proceed with two electrical testing routines: the torture test and the endurance test.

The torture test is made with the flight controls loaded according to the maximum possible efforts found in flight ( 100% stick deflection at maximum speed ). To find the weights I’ll have to put on each flight control, I use the RC calculator spreadsheet.

This value is given in the “Fp max” cell that gives the load at the pushrod on the Control Calc software that is provided with all our kits. This weight is simply put on the flight control at the same distance from the hinging line than the horn height given in the “Yc” cell. I do this for each flight control except the rudder that is vertical by definition.

I then put the plane into the sun to simulate the maximum temperature at the field and activate the servo testing feature on the transmitter. I let the routine go for the equivalent period of two flights.

During the routine I check and make note of the receiver and /or regulators temperature as well as the maximum current consumption.

This routine helps me to check how the servos can cope with the maximum flight loads and the system peak consumption in a realistic environment. It also enables me to verify that there will be no regulator thermal runaway or receiver thermal lock for the Fubata FASST system.

The torture test in progress on the Phoenix

 

2.3. Endurance test

 

The endurance test is very similar to the torture test except that it will be done with lower servo loads and for a longer period of time. It is mostly designed at eliminating the infant mortality failure points and providing a base reading for our statistical log. This reading will be used to evaluate the aging of your system season after season.

To do this I remove enough ballast from the previous test to simulate the load on the flight controls when using 25% of the stick travel at 75% of the estimated maximum speed. Once again I use the RC calculator to find out this value.

I then run the servo test with the weights on but continue until the battery system is empty.

I make a note of the endurance found that way.

I’ll repeat this routine 3 to 5 times. This is done in order to eliminate the possibility of an early component failure and to run in the battery system.

After this routine you’ll have a fairly good idea of how many flights you can safely do with a freshly charged battery system.

Here is the electrical test report table that I fill for each airplane.

1.    Electrical system test

 

 

 

1.1. Individual servo test

center

Drain+

Drain-

Aileron L

 

 

 

Aileron R

 

 

 

Elevator L

 

 

 

Elevator R

 

 

 

Rudder L

 

 

 

Rudder R

 

 

 

Flap L

 

 

 

Flap R

 

 

 

Other

 

 

 

1.2. Torture test

Weight

Temp

Amp

Aileron L

 

 

 

Aileron R

 

 

 

Elevator L

 

 

 

Elevator R

 

 

 

Rudder L

 

 

 

Rudder R

 

 

 

Flap L

 

 

 

Flap R

 

 

 

Other

 

 

 

Receiver temperature

 

 

 

Regulator heat sink temperature

 

 

 

Peak current reading

 

 

 

1.3. Endurance test

Weight

Time

mAh/f

Aileron L

 

 

 

Aileron R

 

 

 

Elevator L

 

 

 

Elevator R

 

 

 

Rudder L

 

 

 

Rudder R

 

 

 

Flap L

 

 

 

Flap R

 

 

 

Other

 

 

 

Time to drain the battery system

 

 

 

Consumption per flight

 

 

 

 

 

 

 

 

3.    Pneumatic system test

 

The pneumatic system can be really tricky to troubleshoot on a completed plane. This is why I consider that an individual component system test can save you a lot of time and hassle.

 

3.1. Individual component test

 

I try to test each component outside of the plane as far as practical. I use a much higher pressure than the operational one for this. I most of the time use a value of 160 PSI. I’ll dip the component in a bucket of water if possible ( not for electronic valves ! ) and check for visual leaks.

The component is plugged to a piece of tube connected to a BVM fill valve and inflated to 160 PSI. It is then dipped into water and checked for leak.

An air tank leak test. Do not dip the gauge into water since it has a venting hole and you might introduce water into the spring mechanism, creating possible corrosion.

Carefully dry the component after the test to avoid corrosion.

If the component cannot be removed easily from the plane or is electronic, I test it by monitoring the leak rate.

I use a pump connected to a pressure gage with a T and very short pneumatic tubes the other end of the T is connected to a BVM fill valve. I then pump 160 PSI in and check how long the device can keep the pressure. A drop of 1 PSI every 5 minutes is a good value.

An air cylinder leak test. Each side of the piston is tested under pressure. You might also want to move the cylinder while under pressure to check for leak at half travel.

 

Note that most of the air tanks made in China have a very high leak rate from the cap seal. I usually fill the cap seal with Hysol E20-NS to get rid of this leak. Make sure that there is no pressure in the tank when you apply the glue.

Every item tested is then identified with a permanent marker to make things clearer.

3.2. In aircraft test

 

I always proceed with a complete test of each pneumatic system after the plane is completed. I check each system one after the other the following way:

I first check the leak rate when the radio is off by pumping the normal pressure in the system

I then do the same test with the system in each state ( gear up , leak check, then gear down ,replenish the air tank, leak check, for example ).

The leak shall not be more that 1 PSI per minute or a 10 PSI drop for 10 minutes.

Note for trouble shooting purposes  that if a leak is detected when the radio is off, it then means that the latter is located upstream of the valve. If it is detected with the radio operating, it is then located downstream of the valve.

I make a note of the leak rate in each system state as a reference value.

 

Here is the pneumatic test report table that I fill for each airplane:

2.    Pneumatic system test

 

 

 

2.1. Component test

160 PSI

 

 

Air tank 1

 

 

 

Air tank 2

 

 

 

Left Main retract

 

 

 

Left main door piston

 

 

 

Right main retract

 

 

 

Right main door piston

 

 

 

Nose retract

 

 

 

Nose door piston

 

 

 

Gear valve

 

 

 

Brake valve

 

 

 

Other

 

 

 

2.2. Aircraft test

PSI/10’

 

 

Radio OFF gear

 

 

 

Radio OFF brakes

 

 

 

Radio OFF other

 

 

 

Radio ON gear

 

 

 

Radio ON brakes

 

 

 

Radio ON other

 

 

 

4.    Fuel system test

A sound and reliable fuel system is essential to preserve your beloved model. Most of the crashes/hard landings are the consequence of an engine failure. A lot of the engine failures that I have seen were due to a fuel system problem ( air bubble, line clogging, fill line venting… )

Here again, the best routine that I have found is to do an individual component check at an early stage and to then do complete system tests as detailed below.

4.1. Component test

The first component that I test carefully is the fuel tank. I first rinse it with raw kerosene to remove any dust or layup residues. I then glue the required hardware on it. When the glue is set I proceed with the leak test. I close the tank with the required hardware and slightly inflate it by blowing air by mouth or hand pump into an open tube. All the other tubes shall be closed. I then dip the tank into water and look at any air bubble escaping.

The Kevlar tank is SLIGHTLY pressurized ( not more than 10 PSI )

I then do the same thing with the air trap tank or UAT.

I finally make sure that the filling system is totally leak proof. On that respect I prefer to use a simple fuel dot system with its threaded sleeve.

The fuel dot is the simplest, yet most reliable fueling system…

4.2. Aircraft cold test

 

I then hook up the complete system in the plane to set the correct tubing length up to the fuel pump. The engine shall not be connected but the system should be in close loop. The pump output or safety valve output should be connected back to the last tank vent. This way the fuel loops backs into the system. I do a functional test by running the fuel pump up to the maximum voltage relevant to the used engine.

The fuel test on the F-84G. The fuel system is looped back to the main tank after the ball valve ( the fest and tygon tubes are joining above the engine FOD, which is not visible on this picture )

The pump is operated via the “test function” menu on the GSU or data terminal. While doing this test routine I make sure that the air trap tank or UAT remains  completely full. I then check carefully the pump outlet/valve outlet to make sure that no air bubble is found there.

The second step is to move the model while doing this test in all the expected  flight situations ( nose up, nose down, and inverted ). In each phase I check the pump outlet/ valve outlet carefully to make sure that no air bubble comes out.

If any air bubble is found at any time, a trouble shooting routine shall be done. Simply check the line upstream to see where the bubbles are generated from. Then re-plug the faulty equipment or change it.

After you have done a satisfactory cold fuel test, you can connect the pump output to the engine for the hot test.

4.4. Aircraft hot test

 

The next step is carried out during the engine test phase. Check the pump output with the engine running at full thrust to see if any air bubble is passing through.

 

Here is the fuel test report table that I fill for each airplane:

3.    Fuel system test

Tick

 

 

3.1. Component test

 

 

 

3.2. Aircraft cold test

 

 

 

3.3. Aircraft hot test

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.    Engine test

Testing the engine is another important step. To make sure that I will not be tempted to do the maiden  flight straight after the test, I usually do as much as I can at the workshop or in the garden ( mind your grass ! ).

5.1. Component test

The first step in the engine test routine is to check the engine components. I use the “test function” menu when the engine is set in the airplane to confirm that every component is working as expected ( the first two points will be already tested during the cold test if you do it ):

  • The pump runs correctly in the correct way ( I prime the fuel system at the same time )
  • The fuel valve is opening correctly
  • The start valve ( kero or gas ) is opening correctly ( I’d prime the gas line at the same time if required )
  • The glow plug is working correctly ( adjust the tension at the same time so that the filament is bright red for a gas start engine)
  • The EGT sensor is reading a correct value
  • The starter motor is working correctly

5.2. Start routine test

 

I then fill up the fuel system and do a short start test. The idea here is to check that the starting sequence is working correctly. I usually do this in front of the workshop up to the end of the start sequence ( learn idle sequence finished ).

During this first start sequence, I make a note of the max EGT and max current drained from the battery ( requires a Hall Effect amp meter to avoid opening the battery line).

The starting sequence shown with a Hall Effect amp meter hooked in to the black ECU supply wire. 8 amperes are drew.

 

When the engine is stabilized at idle I check the heat buildup in the back end of the fuselage. I read the upper fuselage skin temperature with an infra red device. If the value gets above 65 degrees Celsius, I shut down the engine immediately and cool the fuselage down with a blower. This means that an additional heat protection method shall be used ( increase the  Heat Shield + coating or lay up some ceramic blanket or aluminum foil… ). In any case, this step is critical because heat buildup in the back fuselage can result in structural failure or melted servo wire/ damaged servo if not identified at an early stage. The idea is to fly a plane that remains cold or mild in this area even on the ground during taxi.

5.3. First runs

The next step is to do some more extensive engine run -p when the potential start or heat buildup problems are solved.

The engine run up is done primarily to test two things: the max EGT and the acceleration capacity.

If the engine gets a very high EGT or spit flames or hiccups during acceleration, I reduce the acceleration parameter ( low RPM acceleration, high RPM acceleration or acceleration delay parameters )

I also check during this phase that the venturi effect at the engine cone is working correctly. The engine casing temperature taken with an infra red thermometer shall remain moderate ( around 80 degrees Celsius )

I also check the idle RPM and stability during this test. If the idle RPM has a tendency to drop below the minimum value during deceleration, I increase the minimum RPM parameter by a few thousands.

Finally this is the moment to check that no air bubble is entering the engine as explained above.

 

Here is the engine test report table that I fill for each airplane:

4.    Engine test

Tick

 

 

4.1. Component test

 

 

 

Fuel valve test

 

 

 

Fuel pump test

 

 

 

Gas valve test

 

 

 

Starter motor test

 

 

 

Glow plug test

 

 

 

EGT sensor reading

 

 

 

4.2. Start routine test

Temp

Amp

 

Max start EGT

 

 

 

Max start current drain

 

 

 

Fuselage temperature

 

 

 

 

 

 

 

4.3. First runs

Temp

x/x

RPM

Max EGT

 

 

 

Acceleration parameter

 

 

 

Min RPM

 

 

 

Venturi effect

 

 

 

 

 

 

6.    Aircraft balancing

I use a modified Great Planes CG machine to check the position of the Center of Gravity before the maiden.

http://www.greatplanes.com/reviews/gpmr2400-man.html

The modification enables me to balance planes up to 30 kgs/ 66 lbs. It consists in adding two 7 mm carbon tubes to the steel arms to triangulate them. These tubes are linked to the steel arms with Kevlar rows and CA.

The modified CG machine

The horizontal support rods are extended to 70 cm and the graduated rulers extended to 50 cm. Balancing my giant 1/7th scale F-18F from FEJ becomes an easy game with this device.

Remember when you balance your plane that the air trap tank or UAT shall be full. The landing gear shall be extended unless otherwise specified by the manufacturer of the kit. Finally the main tanks shall be empty.

Do not forget to fit the all batteries in the plane and remove all the protective coveres before balancing…

5.    Aircraft balancing

mm

 

 

CG position

 

 

 

 

7.    Radio and range test

7.1. Radio programming

 

Make sure that you note all the travels on a document while programming the radio ( have a look at the document at the end of the article ).

I consider very important to program 3 rates for each control axis for the maiden. I usually go with 0% exponential / 100% travel on the first position, then 15% exponential/75% travel, and 25% exponential/ 55% travel. I am not a big fan of the exponential function, but of course this is a matter of taste and habits.

I also tend to keep the programming as simple as possible initially.

7.2. Programming test or flight simulation

 

The final test that I do in the workshop is a flight simulation after having programmed the radio. I set the plane on its cradle with the pneumatic system refilled and simulate all the flight phases of the maiden as per the pre-established program ( I’ll come back to this point in a future article ).

This includes selection of the gear up, retraction of the flaps, trimming all the channels in both directions, selecting all the possible dual rate combinations, using al the programmed flight modes and any other specific function like wheel brakes,  speed brakes, bomb drops…

The idea here is to check that no programming bug was introduced.

7.3. Range test

 

I finally do a preliminary range test in front of the house to verify roughly that the system is working as expected. For a detailed range test routine, refer to the Weatronic article that I wrote in the previous issue.

Here is the programming and range test report table:

6.    Radio and range test

 

 

 

6.1. Control throws

mm

degrees

 

Ailerons up

 

 

 

Ailerons down

 

 

 

Elevators up

 

 

 

Elevators down

 

 

 

Rudder right

 

 

 

Rudder left

 

 

 

Flaps 1

 

 

 

Flaps 2

 

 

 

Steering right

 

 

 

Steering left

 

 

 

6.2. Programming test or flight simulation

Tick

 

 

Taxi

 

 

 

Brake

 

 

 

Takeoff mode

 

 

 

Gear up

 

 

 

Flaps retraction

 

 

 

Flight mode

 

 

 

Dual rates test

 

 

 

Approach mode

 

 

 

Flaps down

 

 

 

Gear down

 

 

 

Braking

 

 

 

6.3. Range test

Meters

 

 

Range distance

 

 

 

 

Conclusion

 

All the aspects of the pre-flight tests are time consuming. However they might trap some  errors and even save your model. They will definitely make you become familiar with your aircraft systems before the maiden. This will contribute to greatly reduce your level of stress for this decisive event and will increase the chances of a successful first flight.

 

Note that all the complete report table can be found here. I fill this type of table for every plane and it is a great tool to check again all the plane system at the beginning of the flight season and to monitor the ageing of the airframe and components.

The associated file is downloadable on my ftp:

http://www.geohei.lu/olin/data/modelisme/Weatronic/Pre-maiden-procedures.doc

Written by Olivier Nicolas — October 11, 2015

Welcome to Ultimate Jets.

We are the one and only USA based turbine powered UAV and hobby models manufacturer. Ultimate jets offers some of the best engines, kits, and accessories to the Industry. ................................................... We offer in-house design and manufacture services for military and hobby companies. Our expertise extends from aero dynamics design to carbon fiber aerostructures manufacture and 5 axis CNC milling and turning. ................................................... We are the USA distributors for Behotec, BF-Turbines, Mibo and Aviation Design and provide in-house support and service for these products. ................................................... We also are dealers for the following brands: Jets-Munt, Permagrit, Ultratool, Cotronics, Techflex and many other aerospace industry suppliers. ................................................... We finally house a unique technical blog that you will find below, providing industry reference articles. Please feel free to browse through these pages. Enjoy... Barry, Woody, Shaun and Oli.