A year on

2011-03-09T06:06:00.002Z

March 2011.
Not flown yet, good intent yesterday Monday went to the airfield, Sunny, Cold, Windy
Thought I'll see how it goes so took out my Doodlebug which I have been working on (more detail in a bit).
Fitted the tank which had old fuel within and after pulling the starter for a while without success I realised it was not switched on. OK so I did the necessary and away it went. After a short warm up it stopped and would not start again. Waited a while and the same happened after which there was a lot of fuel around.
Made sure that the tank was not pressurized, I have a one way valve on the tank vent which means that it can be pressurized. I found no problem.
Left things for a while and had a cupa then returned to try again. Appeared to be OK so left running for a while on tick over noticed puffs of blue smoke starting to issue from exhast so reved up until smoke disapeared. Left on tick over again, smoke started again until engine stopped.
Wind was strongish with strong gusts,not very inviting for flight and together with engine problems decided to pack up.
During the past months I have been making an SSDR trike. It is based upon the French Pulma 2000 but with wire braces all round in place of struts as per original Pulma 2000 design. I would like to use a Cors Air Black Devil engine and a French Ellipse Fuji 16 wing reinforced for the Pulma trike at the moment I have my sites on two a almost new Fuji at 1950Euro and an older one at 1000Euro. The Black Devil is £1650 + P&P direct from JVC Italia, I dont know what the P&P cost is yet but it seems better than the price in England of £2300
So there is the reason for the working on the Doodlebug, to sell and get the required cash.
I don't know if I will be moving on to Microlights or selling up or making a DIY FLP Unit as yet. Watch this space

THE POWER HG BLOG

2008-02-13T23:18:00.043Z

INDEX
art 1 - Torque for tightening bolts
Art 2 - Safety wires on tuned exhaust
Annex - competition rules (No longer in use)

Art 1 - TORQUE FOR TIGHTENING BOLTS
By John Mayer - blakelow@talktalk.net

This is for the bolts used on the Radne engine which are 5mm and 6mm 12.9 qualiy skt hd bolts
The bolts used on the Radne engine and there have been many instances of these bolts failing especially those that hold the carburettor in place.
This article I write after experiencing a period of several breakages of carburettor bolts on my unit which now seems to have been over come by using the following procedure.
First apply a little WD-40 to the bolts and thread them into their holes. You should be able to thread the bolt all the way in using only your fingers. If the bolt cannot be threaded in entirely by hand, there is some dirt on the threads that will need to be removed before assembly can continue.
Caution
Failure to clean the tapped bolt holes may result in improper torque and seating of the two parts You should feel very little resistance in screwing the bolt completely home. If you encounter significant resistance – STOP – back out, and clean again, if the dirt is persistent then careful insertion of a tap may be required but make sure that the tap does not cross thread. The worst thing you can do is cross-thread these holes. If you do not feel confident, call a friend who has done this before. Repeat this for all holes.
Afterwards, double-check that the bolts thread easily into the holes.
Fitting of new gaskets are some times glued to one of the mating surfaces but notice any small passage, these passages may supply changes in air pressure to drive the fuel pump diaphragm and must not become plugged with sealant. If this passage is plugged or restricted the engine will run too lean, or not at all.
Clean off the mating surfaces. Check that they mate correctly without any signs of rocking when placed together or when lightly bolted together, they should be perfectly flat without any serious scratches or pit marks. Any rocking may be removed by careful honing of the surfaces and using engineers blue- best left to the expert.
Apply a very thin film of high temperature RTV sealant to the mating surface align and fit the bolts finger tight
Torque the bolts
The following steps are very important and should be performed by someone who has some experience with applying torque to bolts.
Caution
Do not torque the bolts to ft-lbs.
Use a torque wrench with the proper in-lbs scale!

The photo below is of my DIY wrench, the lever is 10", measure the pull at 90 deg to the lever and the torque = 10 x the force = lbs ins torque applied.

1. Apply a bit of WD-40 to all bolts and slide them all the way down through the hole until they contact the top of the threaded hole.
2. Using an Allen wrench, thread all the bolts into the part until the head of the bolt just contacts the lock washer. Make sure the part is in level contact with its mating surface. If it is then use this sequence on the cylinder bolts shown below, go around several times and give each bolt ¼ turn until they are all evenly snug.

Cylinder Head Bolts
3. Crank the engine over by hand and verify smooth piston travel.
4. Using an appropriate sized Allen key set your torque wrench to 25 in-lbs or 2.8 Nm and torque the socket head bolts as per the torque sequence on the left.
5. Repeat with 55 in-lbs or 6.2 Nm.
6. Repeat with 85 in-lbs or 9.6 Nm.

Carburettor Bolts
These bolts come usually in 5mm size and therefore although requiring similar treatment to the cylinder head bolts require less torque.
7. Set your torque wrench to 12 ins-lbs or 1.5 Nm and torque each bolt in turn bit by bit making sure the mating surfaces mate correctly
8. Reset to 24 ins-lbs or 3Nm and torque each bolt
9. Reset to 45 ins-lbs or 5Nm and apply final torque

Re-applying torque to the bolts
A word on Static torque vs. Dynamic torque
Static torque is the torque applied to the head bolt while it is stationary. Dynamic torque is the torque applied when the bolt is moving, as when it is being tightened. Static torque is about 30% greater than dynamic torque due to an added friction factor commonly called ‘stiction’. You don’t need to understand the physics. Just remember to loosen the bolt ¼ turn before attempting to re-torque it.
Re-applying torque to is easy
10. After your engine is completely reassembled, start and run it up to normal operating temperatures (approx. 300F CHT). Shut off the engine and let it cool back down to ambient temperature.
11. Loosen each bolt 1/4 turn, and re-torque it to the appropriate torque following the sequence step 1 to 7 or 1,2,7, 8 & 9 dependant on if working on cylinder or carburettor bolts..
Re-applying torque is part of engine maintenance
Each time you run your engine it carries out a thermal cycles. This causes minute changes as the metal parts expand and contract. It is possible for the bolts to loosen as the parts settle in. As a precaution, re-torque the head bolts in-between flights during the first 4 hours of engine time. Thereafter, re-torque the bolts at the beginning of your flying season. A bolt, that had the correct torque prior to being loosened, will return to approximately the same position during re-torque. So it should only require ¼ turn to return the bolt to proper torque.
It is also possible for a bolt which is too tight to exceed it ultimate strength and fail due to increased temperature and vibration.

Art 2 - SAFETY WIRES ON THE TUNED EXHAUST
By John Mayer – blakelow@talktalk.net

Yet again it is reported that a power hang gliding pilot had the misfortune of his tuned exhaust fail and swing into his propeller.
This item (the tuned exhaust) is often retro fitted as a DIY modification and the operator should be fully aware of what needs to be done.
Before commencing any DIY modification pilots should make sure that they are fully aware by checking all avenues of instruction such as the manufacturer of their power unit, wing, harness, what ever the modification relates to, also the BHPA safety committee, also a wide range of experienced pilots who have done the same modification such as can be found upon ‘Yahoo FLPA e-group’.
Here is a photograph which can be found on my album on the above e-group.

This picture shows the safety wire loop fitted between the tuned exhaust expansion box and the muffler. It requires the small stainless steel wrap around bracket to be made, the nut is self locking, the wire is bicycle brake cable and this is looped through one of the spring anchors on the expansion box and securely crimped together as a loop. Should the main bracket between muffler and expansion box fail the loop prevents the muffler swinging into the propeller
In the back ground can be seen similar loops which pass through the springs serving a similar purpose should a spring fail.
This is the latest exhaust made by Radne; earlier exhausts may be more prone to the failure in question and require slight modification to the method of fixing the wire loop.
The exhaust that failed this time had done 100 hrs it is reported, however the wire loop modifications are still required on the latest exhaust.

Aviation requirements:-
1. Have Belt and Braces Always if possible.
2. Any thing that can be Wire Locked then Wire It.
3. Check Every Thing Regularly.

Annex - POWER HANG GLIDING XC RULES

These rule are no longer applicable and are saved for ref only

The aim of this competition is to create something extra for power hang gliding pilots in the UK to aim for thereby making the power hang gliding branch of sport aviation even more enjoyable to the pilot and hopefully creating good publicity for that branch of the sport.
It will provide pilots with a means to compare their performance with others and it could improve their navigation skills, keep their knowledge of air law bright and shiny and improve their confidence. Along the lines of not trying to imposing any restriction on the pilot there will be no entrance fee and will be open to all pilots holding a P rating and a power hang gliding rating and of course flying a powered hang glider. Pilots with a restricted power rating may enter under supervision and must keep within eight nautical miles of there take off field unless flying a declared task under supervision, all as laid down by the BHPA power flight rules.
All pilots must be well aware of air law, be vigilant of air space infringement and obey BHPA rules regarding power hang gliding.

THE COMPETITION
1a The competition will run from November 2008 to October 2009.

2a A flight shall comprise of one take off and one landing

3a All flights must be flown on a foot launched powered hang glider.

4a Maximum fuel load shall be 10 litres.

5a All flights must start and end within an imaginary single 400 metre diameter vertical cylinder the centre of which is defined by co-ordintes usualy situated but not necessarily at the take off and landing field.In order to close a flight circuit the pilot needs to start and finish his flight by at least flying into the 400 metre cylinder when starting and finishing the flight.
Reminder This can be at any point on the flight and does not have to be at a turn point.

Failure to start and finish within the 400metre cylinder will render the flight void

6a Scores will be a simple point per kilometer, however multipiers may apply

7a Each flight must be entered within 28 days of making the flight.

8a The pilot with the highest score from up to six of his best flights at the end of the competion will be the winner. Should there be a draw from six or less flights then the pilot with the highest score from his last flight will be the winner down the flights 6, 5, and so on.

TYPES OF FLIGHT

1b Out and Return Flight: -
These commence at a cordinate start point, can go round one or two turn point coordinates and finish at the original start point, see 5a above. The greatest distance between two co-ordinates is scored.

2b FAI triangle: -
These flights commence at a co-ordinate start point, go round three turn point coordinates one of which may be the start point and finish at the original start point, see 5a above. Score will be the total of the straight line distance between the co-ordinates of the FAI triangle
An FAI triangle is one that satisfies the FAI 28% rule i.e. the shortest side of the triangle flown must be 28% of the distance flown. It is adjudged that extra planing and navigation is required for an FAI triangle therefore a multiplier of 1.15 will be applied to the score for this type of flight.

3bDefined flights.
Before flying a defined flight the pilot must notify his intention by e-mail, TEX message or any other method which records the date and time sent and giving the proposed co-ordinates which must be the co-ordinates of the turn points and the co-ordinate for the centre of the 400 metre cylinder for his start and finish points.
blakelow@talktalk.net or mobile Tex to07793579323.

4bDefined out and return
The defined out and return flight is identical to the undefined out and return flight (see 1b) except that the pilot states where he is going to fly before taking off (see 3b above)
It is adjudged that some degree of extra planning and navigation skill is required to fly a defined out and return therefore a multiplier of 1.1 will be applied to the score.

5bDefined FAI triangle
Here again the defined FAI triangle is identical to the undefined FAI triangle (see 2b above) except that the pilot states where he is going to fly before taking off.(See 3b above)
It is adjudged that further skill is required to plan and fly a defined FAI triangle therefore a multiplier of 1.2 will be applied.
Should the pilot fail to complete the defined triangle then the greater distance of either an undefined out and return or FAI triangle will be used to score.

Visiting Flight
This is a special task to allow pilots to score points whilst taking part in a "Fly In" or visiting a different flying field.
The scoring and distance rules are as per the defined out and return flight
except the scoring distance will be the straight line distance between the take off/Landing field and the defined visiting field only. The task must be completed on the same day within daylight hours as defined by Air Rules.The pilot may land and refuel if necessary at the single defined visiting field only.
A mutiplier of x 1.1 will be applied to the score which will be 1.0 point per Km flown.This type of flight may require the pilot to be familiar with airport landing and take off procedure.

NOTE In the 2008 power league competition it became evident that using a rigid wing gave more kilometers than a flex wing in order to try and create a fair handycap for pilots using this type of wing a multiplier of 0.82 will be applied. This multiplier was derived from evidence that the rigid glider flies at an average cruise speed in level flight of 56 Km/hr whilst the flexwing flies at an average cruise speed of 46 Km / hr.

1c EVIDENCE & HOW TO MAKE YOUR ENTRY: - Your flight must be proven through the presentation of a GPS track log showing
that no intermediate landing has been made and must show turn points, take off and landing points.
Interuptions in the track due to loss of signal will not invalidate the flight providing gaps do not bring into question the continuity of the flight.
If your track is over or under restricted airspace that has a lower limit of 2500ft ASL or less or is from ground level to an upper limit e.g. ATZs, CTRs etc. then altitude data is required. No altitude data the distance your track is covered by restricted airspace will be deducted from your distance.

2c GPS HELP: -
Your GPS units set-up / map datum should be set to degrees – minutes and wgs84

3c RECORDING THE TRACK-
First clear the track log before taking off also make sure that the track log recording is on.

4c DOWN LOADING YOUR TRACK:-
In order to do this you need to down load to your computer a small
programme called GPSDump. Search for the free download of this software on your computer, make sure you download the latest version. Run the program and follow the instructions as follows.
1· Set your GPS for data transfer.
2· Set the com port in GPSDump by selecting Misc / set com port from the main menu.
3· Read the track log by clicking Logs on the main menu, and then select your flight instrument/GPS type.
4· Your track log will then be read into GPSDump.

5c CREATE YOUR IGC FILE:-.
1.With your track log displayed on your computer it is important to select the portion of the track that relates to your flight and does not include your manoeuvres
around the field etc before and after the flight.

2.To find the start of the flight on your IGC file first make sure you have the correct date then scroll down to take off time.

3.Scroll down until significant changes in speed and / or altitude that show your
take off, go back a little to find a track point just before take off, the position data remains fairly stable before take off.

4.Mark the start by clicking in the date column.

5.Scroll down to the end of your flight and double check that the data is all on the date of your flight, press and hold the shift key and click on the date column to select a track point shortly after landing. This will highlight all the data between take off and landing.
Older computers just highlight by pressing and holding the left mouse button and move the mouse to scroll down to your flight end.

6.With the appropriate track data highlighted, select File /Save flight log/.IGC ) from the main menu.

IMPORTANT Don't forget to enter these details below if you fail to give them, your flight will not be entered in the competition
Fill in your name and where your launch / landing field is, email address, BHPA number in the details space, enter glider and unit details, press save and take careful note where the flight log is being saved on your computer.

6c UPLOAD YOUR TRACK LOG to blakelow@talktalk.net

Find the saved file on your computer and raise an e-mail with the file attached and send to the above address where hopefully I can resurrect your flight complete with
calculations on straight-line distances flown on Google Earth.

If you have any photographs or stories about your flight that you don’t mind being published then include these in your e - mail.

OPEN DISTANCE
A request has been made by a pilot for an open distance class to be added. Because this type of flight may be wind assisted which is an un-known quantity it is deemed unfair to place this type of flight along side circuit flights, a separate section is therefore added for these flights.All that is required is a complete IGC file showing the complete flight together with co-ordinates for your take off and landing. In order to enter the flight you must enter all your details including glider, unit and BHPA number as detailed above. One point will be awarded per Km flown and it will not count towards the circuit competition.

Best of Luck,

John

PointsITEMS THAT MAY BE OF INTEREST

Correct torque of quality 12.9 socket head 5 & 6 mm diameter bolts as used on the Radne Raket engine

By John Mayer

The 6 and 5 mm bolts are used on the Radne engine and there have been many instances of these bolts failing especially those that hold the carburettor in place.
This article I write after experiencing a period of several breakages of carburettor bolts on my unit which now seems to have been over come by using the following procedure.
First apply a little WD-40 to the bolts and thread them into their holes. You should be able to thread the bolt all the way in using only your fingers. If the bolt cannot be threaded in entirely by hand, there is some dirt on the threads that will need to be removed before assembly can continue.
Caution
Failure to clean the tapped bolt holes may result in improper torque and seating of the two parts You should feel very little resistance in screwing the bolt completely home. If you encounter significant resistance – STOP – back out, and clean again, if the dirt is persistent then careful insertion of a tap may be required but make sure that the tap does not cross thread. The worst thing you can do is cross-thread these holes. If you do not feel confident, call a friend who has done this before. Repeat this for all holes.
Afterwards, double-check that the bolts thread easily into the holes.
Fitting of new gaskets are some times glued to one of the mating surfaces but notice any small passage, these passages may supply changes in air pressure to drive the fuel pump diaphragm and must not become plugged with sealant. If this passage is plugged or restricted the engine will run too lean, or not at all.
Clean off the mating surfaces. Check that they mate correctly without any signs of rocking when placed together or when lightly bolted together, they should be perfectly flat without any serious scratches or pit marks. Any rocking may be removed by careful honing of the surfaces and using engineers blue- best left to the expert.
Apply a very thin film of high temperature RTV sealant to the mating surface align and fit the bolts finger tight
Torque the bolts
The following steps are very important and should be performed by someone who has some experience with applying torque to bolts.
Caution
Do not torque the bolts to ft-lbs.
Use a torque wrench with the proper in-lbs scale!
1. Apply a bit of WD-40 to all bolts and slide them all the way down through the hole until they contact the top of the threaded hole.
2. Using an Allen wrench, thread all the bolts into the part until the head of the bolt just contacts the lock washer. Make sure the part is in level contact with its mating surface. If it is then use this sequence on the cylinder bolts shown below, go around several times and give each bolt ¼ turn until they are all evenly snug.

Cylinder Head Bolts
3. Crank the engine over by hand and verify smooth piston travel.
4. Using an appropriate sized Allen key set your torque wrench to 25 in-lbs or 2.8 Nm and torque the socket head bolts as per the torque sequence on the left.
5. Repeat with 55 in-lbs or 6.2 Nm.
6. Repeat with 85 in-lbs or 9.6 Nm.

Carburettor Bolts
These bolts come usually in 5mm size and therefore although requiring similar treatment to the cylinder head bolts require less torque.
7. Set your torque wrench to 12 ins-lbs or 1.5 Nm and torque each bolt in turn bit by bit making sure the mating surfaces mate correctly
8. Reset to 24 ins-lbs or 3Nm and torque each bolt
9. Reset to 45 ins-lbs or 5Nm and apply final torque

Re-applying torque to the bolts
A word on Static torque vs. Dynamic torque
Static torque is the torque applied to the head bolt while it is stationary. Dynamic torque is the torque applied when the bolt is moving, as when it is being tightened. Static torque is about 30% greater than dynamic torque due to an added friction factor commonly called ‘stiction’. You don’t need to understand the physics. Just remember to loosen the bolt ¼ turn before attempting to re-torque it.
Re-applying torque to is easy
10. After your engine is completely reassembled, start and run it up to normal operating temperatures (approx. 300F CHT). Shut off the engine and let it cool back down to ambient temperature.
11. Loosen each bolt 1/4 turn, and re-torque it to the appropriate torque following the sequence step 1 to 7 or 1,2,7, 8 & 9 dependant on if working on cylinder or carburettor bolts..
Re-applying torque is part of engine maintenance
Each time you run your engine it carries out a thermal cycles. This causes minute changes as the metal parts expand and contract. It is possible for the bolts to loosen as the parts settle in. As a precaution, re-torque the head bolts in-between flights during the first 4 hours of engine time. Thereafter, re-torque the bolts at the beginning of your flying season. A bolt, that had the correct torque prior to being loosened, will return to approximately the same position during re-torque. So it should only require ¼ turn to return the bolt to proper torque.
It is also possible for a bolt which is too tight to exceed it ultimate strength and fail due to increased temperature and vibration.

A WAY OF CALCULATING THE LENGTH OF THE 3rd LEG TO FOLLOW THE FAI 28% RULE
leg A + leg B divided by 2.5715 = lrg C. Of course leg A and B must be approx of equal length and at least longer than leg C