CC Ground Incident - An unfortunate coming together of CC and our tug mover has had the consequence of wrecking the 4 blade propeller and rendering the tug mover u/s.
The tug has been refitted with a stock 2 blade propeller, the engine fortunately, has not been damaged. The tug is serviceable but I would suggest we consider it as a backup to the others. If we do use it for towing, as you might expect, it displays similar characteristics to YM. Climb parameters are unchanged, for descent use 2100rpm and 110kts, this speed is conveniently marked with a yellow pointer.
The tug mover should be fixed on Jan 21st, so we have a few days of pushing and shoving. Be careful with the propellers when you do this.
CC - A recent check of instruments in CC has revealed errors in it's VSI. ASI and RPM are accurate and so the normal descent parameters apply though that might occasionally indicate higher rates of descent.
In future we will try and display this type of specific information on the panel itself.
Update on the Patch - You will have noticed it has been disappearing into it's surroundings as the grass thickens, so to remind everyone of it's position a white line is now in place around it.
The area's primary purpose is to reduce undercarriage pounding to tugs and gliders during aerotow take-offs, which it has done very well so far. If we can keep vehicles and aircraft (unless they are taking off, of course) off the area, it should serve us well into the future. So please stick with the guidelines below.
New Idents on the Tugs
A glider pilot should be able to identify the tug he or she is being towed by and hopefully the letters placed on the right flap should allow this. This in turn should facilitate communications where required. We should all encourage positive radio contact between tug and glider. Most useful in an emergency situation, but also if the glider pilot has a change in requirements.
New Patch - We have started to use the newly levelled and seeded area on the SW run. It is still a liitle soft and bare in places but with the following provisos it can be used for aero tow and motor glider take-offs only;
- It is not wet or obviously soft
- That any manoevring for take-off is done prior to entering the new surface
- That each take-off be on a different line
- Please brief that any other use of the patch will have consequences!
Aerotow Retrieves - A couple of issues recently has prompted me to remind you all of the correct procedures when an aerotow retrieve is called for.
Please read the section on Aerotow Retrieves in the Tug Pilot Manual which clarifies these requirements.
Also note that until further notice both Eaton Bray and Holmbeck Farm are to be considered as "fields" for the purpose of aerotow retrieves.
Aircraft Update
CA - Prop issue resolved now fully serviceable.
CB - New engine bedded in, new tuned silencer has improved performance, fully serviceable.
CC - Camshaft failure has required major engine work, engine is now fitted and producing more power than before. Coupled with the ITP propeller the engine will reach red line at 78kts. At top of tow it is really important to have a slow power reduction, in order to do this and not go over the red line you will inevitably climb a bit after release. That's fine - look after the engine. The engine also requires "cutting" oil.
YM - Annual complete with many new components, particularly legs and oleos, fully serviceable.
UA - Having a year off.
CB - Please note tacho is currently over-reading by 120 rpm, please adjust parameters accordingly.
As this now has a new engine please be especially careful with power changes. This engine also requires cutting oil - see notes in the hangar.
What's happened to all the tugs? - Right now we only have YM and CC available.
UA - The Super Cub is likely to be out of action for the entire year. We have finally bitten the bullet to re-cover the aircraft and that will almost certainly reveal other necessary repairs as the fabric comes off. This will be treated as a background job with entry back in to service planned for 2012.
CB - CB is the major project this winter. It is currently being fitted with a new engine. The standard 4 blade propeller has been refurbished and will be fitted to this aircraft. Additionally we will be replacing the old exhaust system with a new tuned arrangement. This will be done seperately after we have had a chance to evaluate the performance improvement from the engine/prop combination. Due out by March.
CA - CA has developed a prop control problem. This is an unusual and rare (I hope) failure, both engine and prop have been removed to facilitate a fix. Due out in a couple of weeks?
More Snow - Last year we managed some great flying in the snow, however, this recent snowfall, is deeper and of a consistency that doesn't compact to a workable surface. This has thwarted any flying from it so far. One thing is certain it will become very muddy at some point. So whether we can fly or not depends on many things and I repeat the message posted around this time last year.
Tug Take-Off Performance - Some awkward conditions recently have highlighted the need for us all to be more aware of tug take-off performance.
One example; SW run on a frosty frozen surface produced quite decent performance but as the day went on the top few millimetres of soil melted into a sticky, draggy surface which increased the take-off distance noticeably.
Another example; Taking off from Hangar Ridge with a SE wind, not only caused the inevitable long ground run, but also seriously poor climb performance. In this instance and always on NE run take-offs we need to identify a V1 (Continue OR Abandon take-off) point. This point should allow glider and tug to stop in the remaining field and clearly if the tug is not airborne by this point the tow should be abandoned. The TPM contains guidance for this.
Also we should be aware that generally a downhill take-off with no wind is safer than an into wind take-off uphill. I know we are sometimes constrained to launching from the NE run because of the presence of the winch, and we need to satisfy ourselves that performance is acceptable. Finally we must all realise that there are some circumstances at Dunstable where aerotowing is inappropriate.
Take a look at AIC 127 which gives some general guidance. There is a direct link under "AICs" under the "Operational" tab.
Tug Starting - We've had a bout of starting problems as you are all aware. We've also had a number of starter breakages. In all of that I might have suggested some abnormal starting methods to some of you. However, having weighed up the problems with Aidan, we have decided sticking with the standard start method is best.
As a reminder for all tugs; we must start on the LEFT mag only. Once the engine runs we should switch the right mag on.
CA does this automatically, UA; switch Left switch on, then Right switch on when engine runs. All the other Robin's; Select Both then back one click, start engine, then select BOTH again.
State of the Airfield - I am sure you have noticed this, but the airfield is rougher now than I have ever known it. The Robin does a good job of riding the bumps but is clearly taking a hammering in the process. Here are a few suggestions to bear in mind.
Try and identify a favourable take-off run or at least try and miss the obvious bumps.
Keep the stick well back during the take-off roll to offload the nose gear as much as possible.
Taxi much slower than you might have done before and be alert to the oleos bottoming out, report soft oleos to Aidan.
CA and YM have less prop clearance than the other Robin's and there is a real risk of a prop strike. Taxi them slowly and try and keep the nose running over higher ground.
Manning Tugs - There have been a few weekend days recently when we have needed tug pilots and had difficulty finding someone. Trying to roster for maybe 4 tugs would be impossible and an imposition, but we clearly need to fly up to 4 tugs on occasions. So whilst you have a commitment via the roster for half a day every few weeks, please try and tow or be available to tow on other days particularly if they look good weatherwise or you can anticipate a lot of towing.
I expect 30 to 40 hours a year from a good regular tug pilot and to achieve that you will need to be proactive on opportunities.
You will also notice we are back to Summer rostering, there is a reminder on what that commitment is below the roster.
Tug Upsets - The BGA have considered it necessary to remind tug pilots of the dangers of a tug upset. You can read their comments here. The explanation and guidance on an appropriate response can be found in the Tug Pilot Manual, the advice has not changed but is definitely worth re-reading.
The important point is to reference any unusual activity from the glider against the effect it has on the pitch attitude of the tug. You may remember my nagging about correct pitch attitude after take-off. Setting the trim correctly and achieving the correct pitch attitude is very important, This is the datum from which you can judge a misplaced glider. From the Tug Pilot Manual; "...if a gentle back pressure is insufficient to prevent any nose down pitch - release immediately". DO NOT DIAGNOSE - JUST RELEASE. Once you are above 600' you can give the glider pilot more opportunity to correct.
One of the incidents mentioned by the BGA occurred at Dunstable during the summer, but we also had another incident where the glider pulled up after release but forgot to pull the release! This can feel pretty uncomfortable from your perspective, being suddenly pitched down without warning. However, the the weak link will give way and the tug will recover almost immediately, leaving you to replace the rope and consider your words to the errant glider pilot.
Having your hand on the release during take-off is not a good idea. However, including a "touch" of it at the end of your before take-off scan is a good practice. Try practicing operating the release, from either hand, in each of the tugs when you get the opportunity. Also remember the force needed will be greater under load.
Starting Problems and a warning - In recent weeks we have had a couple of tugs which have been reluctant to start. Overcranking is damaging and a potential fire risk. We lost our first and best Robin by fire after an extended period of cranking. During cranking, the solenoid gets incredibly hot and that combined with a lot of fuel presents a real fire risk. Please adhere to the following limitations regarding the starter motor on all of our tugs;
Additonally, if it is known that the problem is an erratic impulse magneto, then only a short burst should be used. If the impulse doesn't work on the first crank then extended cranking will not help. Wait then try another short burst in this scenario.
Rough Surfaces and Bumps - The surface at Dunstable has never been particularly smooth, however, some areas have become much worse in recent times. Take a look at the view of Dunstable and note the black lines which denote the worst bumps.
The one on the West run is well known and there is not much we can do about it.
On the SW run the old fence line has produced a line of potentially damaging bumps, we do need to avoid these with the tugs (and gliders) until such time as a fix can be made. So from now on we should avoid landing in the area marked B, and avoid taxiing in area A. We can still taxi in B, but only slowly and with care.
There is also an annoying bumpy rectangle on the SW take-off run marked with a rectangle on the diagram, we need to avoid this during take-off. We hope to spray paint the leading edges in the near future.
Finally the surfaces of hangar ridge, the transition from the steep to flat part of the T/O run and the area close to the clubhouse are worse and there is a real risk of dinging a prop. So choose your route carefully and taxi slowly, very slowly in some places.
CC Damaged - CC is unserviceable due to hangar damage. The incident occurred sometime this week as a result of pushing it into the hangar racking with some force. Clearly avoidable damage and worse for not being reported. I accept it might not have been a tug pilot. Either way, these are your aircraft, take care of them.
Tug Take-Off Performance - Some awkward conditions recently have highlighted the need for us all to be more aware of tug take-off performance.
One example; SW run on a frosty frozen surface produced quite decent performance but as the day went on the top few millimetres of soil melted into a sticky, draggy surface which increased the take-off distance noticeably.
Another example; Taking off from Hangar Ridge with a SE wind, not only caused the inevitable long ground run, but also seriously poor climb performance. In this instance and always on NE run take-offs we need to identify a V1 (Continue OR Abandon take-off) point. This point should allow glider and tug to stop in the remaining field and clearly if the tug is not airborne by this point the tow should be abandoned. The TPM contains guidance for this.
Also we should be aware that generally a downhill take-off with no wind is safer than an into wind take-off uphill. I know we are sometimes constrained to launching from the NE run because of the presence of the winch, and we need to satisfy ourselves that performance is acceptable. Finally we must all realise that there are some circumstances at Dunstable where aerotowing is inappropriate.
Take a look at AIC 127 which gives some general guidance. There is a direct link under "AICs" under the "Operational" tab.
Vintage Gliders - Wherever possible use UA or YM for towing them. For YM tow at 60kts IAS, which with YM's ASI error will give a 55kt tow to the glider. Leave flaps in T/O position and remember to retract them just before release. Monitor #3 CHT gauge, if temp is still increasing at 2000' either speed up 5kts or wave glider off. Either way take a bit more time to reduce power.
For CB and CC, slowest tow speed we can offer is 60kts, which may be too fast for the glider, so check. CA is not suitable for vintage gliders, not slow ones anyway.
Letter to Tug Pilots - PC has written to you all recently on a number of points. I agree with the points raised and I also recognise that it requires a degree of self discipline to avoid drifting away from our tried and tested standard procedures. All the information you need to do the job well is contained in the tug manual and other parts of this website. I urge you to revisit it from time to time and keep yourself in tune. I also agree that we probably do have the best towing operation of any Club and that is the sum of all our contributions. You should be proud of that and your place in that team.
You can review the letter here.
Starters and Starting - You may be aware that we have suffered a number of starter failures in the last year or so. Aidan has been replacing them with the newer and, so far, more reliable "Skytech" type, only UA and CA still have the old type. With them comes a warning though;
It is important that the engine is started with the LEFT MAG only selected. This is to avoid the engine "kicking back" which can be very damaging and very expensive. This has always been the correct procedure but it is especially important now due to the increased speed at which the starter now cranks the engine. It is fast enough, in fact, for the right mag to produce a spark without the aid of an impulse spring as fitted to the left mag. The right mag is further advanced than the left mag hence the risk of "kick back" during starting.
Airspace and Transponders - Transponder usage is coming and it'll soon be mandatory on light aircraft. So far only CA, CB and YM have transponders and they are mode A only (no height output). CC will come back with a Mode S transponder and eventually these will have to be fitted in all the tugs.
Once you switch the transponder on, the world knows your precise position and with mode S your altitude and callsign too. It is imperative, that as a tug pilot, you know your options and position accurately. If you have a C of Ex Revalidation this winter you will have the benefit of a one to one session on the subject, if not you will probably want to get one. Knowing boundaries precisely and optimising your tow patterns is the theme.
There are a few new concepts and procedures to learn:
Knowing which Airspace is available and it's implications. How to glean this information if it's not obvious and how we should use the transponders we have. All this is presented on laminated cards which will reside in each Tech Log. There are also detailed maps which will allow you to identify points on and around the boundaries. You should refer to the appropriate diagram when towing and use your towing activity to improve your personal knowledge.
You can view these details by following this link or the one in "Op Info".
Bent prop - On investigating a drop in performance with UA, it was discovered that the prop was bent at one end. It can only have occurred by pulling the aircraft from the tip of the prop. Whilst I can't believe any tug pilot would have done this, it may well have been done by "willing helpers".
Please avoid contact with tugs as much as possible, use the tug mover for the Robins and supervise moving the Super Cub carefully. Only pull on the prop at the root, no pushing on the tailplane, and if you have to push on the struts do it close to their attachments to the fuselage.
Precautions to take
- Operate carb heat immediately after a cold engine start.
- Operate carb heat prior to take-off.
- Check that max rpm is attained during take-off.
- Operate carb heat in descent, if the flight has gone up to or beyond cloudbase.
- Operate carb heat during or after prolonged ground running.
- Operate carb heat during the approach checks as normal.
Remember normal carb heat operation is to select for 10 to 20 seconds and then return to cold.
A few days recently have started with a frost and sub zero temperatures. In such cases, DI the tug|(s) in the hangar and then pull out just before they are needed, start up and warm up as soon as you can and then tow straight away if possible. This should reduce the possibility of frost forming on the wings and engine parts.
Airspace Changes - May 11th saw some major changes to our airspace. Every pilot must have an airspace briefing. Not surprisingly there are some changes to our tow procedures as a consequence.
1. It is now unlikely we shall tow above 4000' agl.
2. The tow out route South of the airfield when Luton are using 08 is essentially unchanged. The 1000' box is now superfluous and you can route further South if you wish, however, you must exit this box North Eastwards before climbing through 1000'agl. Click here to check the diagram.
3. When Luton are using 26; CTA8 may be used to 4000' agl. Also glider pilots may use LGC 26 Airspace, subject to radio clearance. Click here to check the chart.
4. When Luton are using 08; The railway line effectively limits our towing to the West, though this unlikely to trouble us with an Easterly wind. The Spin area is available to 4000' agl and you will need to learn the new line. The "Tree" still features, the Totternhoe Quarry and the one by the A5 help to locate the Southern boundary. The A5 neatly defines the Eastern end. Click here to check the chart.
5. Infringements by gliders, or tugs for that matter, can't be tolerated. As a tug pilot you should be alert to anything in the "wrong" place and you may have to "fly alongside" to alert the pilot that he is somewhere he shouldn't be.
6. If you are not sure about any of this, please ask Andy or me for further clarification.
Use of 26 airspace for towing - Before flying, the office will contact LATCC and give notice of our intention to start flying. They will respond with the area that we may use. It will be determined by the operational runway at Luton, but there are also other factors which may preclude our use of 26 airspace. It is no longer acceptable to monitor the Luton ATIS for this purpose. You will have to check with the office. Obviously if the airfield status is 26, you can assume we have 26 airspace and tow accordingly. If the status is 08 because of the lack of tower controller for example, but LGC has been given 26 airspace then we should make full use of it. In this case remember to drop the glider close to the 08 boundary line or beyond.
Also when the status is 26, encourage glider pilots to request 26 on tow. This will give you greater flexibility with routing and allow the release to be inside 26 airspace.
Stones & Propellers - After the recent dry weather some areas of the field, particularly near the Clubhouse, are full of small stones and grit that will and does damage our propellers. Generally they are easy to spot as areas without a grass covering. When pulling out tugs take them far enough in to the field so that the propeller is not located over one of these bald patches and that the subsequent taxi out can remain over grassy areas. Likewise when returning for fuel approach the stopping area from the East. See the pictures below. After refuelling make sure the tug is located for taxiing such that you again avoid these areas.
Note the area with puddles, these are now dry and contain the offending
material, along with similar areas.
Please stop all tugs except the Super Cub, short of the peri-track and pull the aircraft to the pumps using the tug mover. Likewise for starting, all tugs except the Super Cub must be pushed back to the airfield side of the peri-track. I know this a pain at times, but plans are still ongoing to provide a peri-track crossing point and a taxi in - taxi out refuelling system. Work should start on this in the near future.
Finally do NOT coast across the peri-track with the engine stopped. It can only mean you have not shut down correctly and it looks and is quite unprofessional.
DI's - In addition to the normal aircraft check, please also check or do the following;
- Spare Rope - On board and correctly stowed. This means that the metal parts should be in the centre of the bundle and the whole bundle under the parcel shelf bungees.
- Propeller - Please clean before flying each day. Get rid of the bugs to ensure the propeller works as efficiently as possible.
- Oil - The guidance given under "Op Info" is still valid. Long operational days are now possible, so make sure the oil level is appropriate for the coming day.
Curvy skid for XI - A newly designed skid is now attached to XI. Apart from the obvious, it is designed to avoid damaging the tail end when being reversed into the tug hangar. It is only the right side that causes problems, so take extra care when using that side. The other skids may be similarly modified if this idea works.
Pilot Recency - This is a reminder to all pilots that you must fly each type at least once in the preceeding 3 months. Our current "Types" are Robin(Fixed Pitch prop), Robin(VP prop) and Super Cub.
For the Super Cub, it has been out of service for so long now no-one is current on it. Expect to see a refresher program for all Super Cub pilots published soon.
For CA, this has been out of service for 7 weeks now and it is likely some of you will be out of recency on this. It is due to return to service this week-end. If you find you are out of recency on it, contact me, Andy or Pete to arrange a refresher session.