Taming the Big Lanc
(An extract form the CMFC news letter)
Firstly, without Terry’s great trust in allowing me to fly his pride and joy this article could not be written. Thanks Terry for the privilege!!
Whenever Pete and I fly the Lancs at public events, we tend to get barraged by other modellers who are keen to know what they’re like to fly. The assumption is that, just because they’re big and have four engines, they must be tricky to fly. Well I’m glad to say that, with the odd exception, they’re just like big trainers! Don’t get me wrong, if you don’t treat them with respect they will ‘bite’ and those that witnessed the demise of Terry’s Mk 1 version can testify to this. Spinning is not recommended!
Preparation and pre-flight checks are vital and should be approached methodically. The initial assembly requires checking of all internal systems carefully for transit damage, installing the main RX NiCad and anchoring the nose ballast (lead). Careful attention is paid to all plug connections and these are taped over for added security. The wing is retained by dowels at the front and two large steel bolts at the rear. The cockpit cover is secured with screws and the wing center cover with sprung hatch catches.
With everything assembled we give her a good look over to check linkages, hinges, fin security, undercarriage and finally the engines. Once everything has been inspected she’s ready for fuelling. With four twelve-ounce tanks she gets through quite a lot of fuel. A weekend show will consume over a gallon!
Starting any four-engined model requires both time and patience. The logistics of getting four engines running happily consumes a lot of time and requires the TX ‘peg’ for at least the slot before we intend to fly. Starting the engines requires four people. If you rush it, accidents can occur or you may get airborne and lose an engine at a critical point.
· One to
hold the transmitter and operate the throttles.
· One to hold the glowplug nicad/lead and operate the chokes.
· One to operate the electric starter.
· One to anchor the tail.
Fortunately there’s always a groundcrew ready and willing to help!
Once I have the transmitter and peg, I switch on and check all functions. I then set the failsafe as follows:
· Outer engines
· Inner engines at about ¼ power.(prevents nose down by helping elevator work)
· Aileron neutral
· Elevator slightly up.
· Rudder slightly left or right (depends on operating circuit of the day). If she goes into failsafe just after take-off I want her to turn away from the crowd.
Starting commences with the starboard outer, working along the wing in turn to the port outer. The throttles work in pairs, the main throttle stick operates the inners as a pair and the extra stick the outers. We use a modified Fleet PCM 7 transmitter, which is ideal for this. Before the first flight of the day, each engine is started, set on it’s own and then shut down. Max RPM is measured on a digital tacho and then the mixture is richened slightly for safety. The inboard O.S. 70 Surpass’s top out at about 10.000 rpm on their 13 x 6 props. The outer Saito 40’s give about 9500 rpm on their 12 x 5’s. Synchronized RPM is not the slightest bit important, it’s reliability that you’re looking for. I have never known any of them to rev the same.
Once all have been individually run, they’re all started together from starboard to port as before. A full power check is performed both on the ground and with the nose held up.
I now check over all the flight controls again and if necessary operate the failsafe for the show organizers. This will then require a full restart again but keeps the safety officer (and me) happy that all is well.
Taxiing out requires physical help to restrain and guide her to the takeoff point. Without brakes, and in the confines of a show, this is a wise precaution.
Once at the takeoff point, I run her up to full power (inners first, outers second) and check for engine ‘note’. If in doubt I richen the offending engine slightly. Once again I go through the pre-flight checks and check both the takeoff run and approach.
You need to be relaxed, confident and fully aware of what you are doing at this point. You also need to have assessed what you would do if something goes wrong during takeoff and what your options are. Just like the full size, you need to know where your takeoff decision point is (V1) and stick to it.
Rudder authority on the ground is poor as you start the takeoff run, and a crosswind requires a lot of work to keep her straight. As speed builds up, rudder authority increases and all is well.
I open up the inners, then the outers, and if everything looks good, and with a bit of up elevator, I signal for release. As I said before, you need to work the rudders quite hard at this stage to keep her straight. As speed builds I ease off the ‘up’ elevator and give slight nudge of down to ‘unstick’ the tail. When she seems ready you ease back on the stick gently and she rises into the air. Climb out should be fairly shallow to allow speed to build up before the first turn. If you loose an engine during the takeoff run, and there’s sufficient room, shut them all down and stop. Unless you’re out of room and have sufficient speed, don’t try to takeoff on three, it’s not worth the risk! If you’re committed, pray that it’s the crowd side engine that’s stopped so that your first turn is away from it! A prop watcher is useful here.
The transmitter has 100% rudder to aileron mix, which I switch in as soon as she’s airborne. Without it, the tail tends to ‘hang down’ in the turns and the subsequent drag reduces speed. Even with this I tend to give additional rudder in right hand turns just to keep her in ‘balance’. This is particularly important if the first turn after take off is right handed.
In the air and at height I reduce the outers and inners to about ¾ power. This helps to reduce the possibility of one engine stopping. She flies quite happily at this power and I only throttle up the inners to full power after a low pass.
Handling in the air is ‘ponderous’ but very predictable. You just have to think forward a little to compensate for the momentum. I would go so far as to say that, I’ve flown a lot of trainers that are harder to fly! With the extra power of the 70’s this year I was happy to give Terry his first go on the sticks this summer. The smile afterwards said it all!! Not quite ready for a landing/takeoff yet, but a step in the right direction.
Landing is all about engine and speed management. You need to get the power levels right at each point of the circuit to ensure that she’s in the right place at the right height at the right time. I ease back the outers on the downwind leg to about 1/3rd. This starts a gentle sink and keeps the speed up for the turn onto base leg. After turning onto ‘base’ I pull back the inners to about ½ power and sink increases. You need to balance speed with attitude using the elevator. After turning onto ‘finals’ I bring the outers back to idle and adjust the sink with the inners until it’s right for getting her over the threshold in the correct position. As she crosses the threshold, I bring the inners back to ¼ and bring her in on elevator. If you pull the inners back to idle there’s not enough elevator power to round out! If you need to ‘go around again’ for whatever reason, remember, inners up first and watch for engines going out on you. Once on the ground, the inners come back to idle and you’re working the rudders hard again to stay straight until she stops. She will taxi on the inners but it’s best to get the helper out there again and guide her in. Once back in the pits, I shut her down a breath a sigh of relief!!
There’s quite a lot to think about with a model like this and it pays to take your time. Show safety officers and other flyers understand this and tend to give you the time you need. Quite often they want to watch anyway!
Terry and I have just started to build another Lanc, which will be more scale and will have both flaps and retracts as well as working bomb bay. This one will represent ‘9J-V’ of 227 Sqn. and the aircraft flown by my father in WWII. With a bit of luck it should take about a year or so to get her in the air.
I hope this has
given you an insight into flying four engined models and look forward to seeing
you at one of the shows next year. Both Lancs, the Manchester and Catalina in
the air together are an awesome sight and sound.