H.201 Standard Libelle notes

© Martin Gregorie, December 2021.

Cockpit and storage space

The chief problem with Libelles, if you're thinking of buying one, is cockpit size. The cockpit is generally long enough for most pilots but is quite narrow, so if you have more than averagely broad shoulders you may not fit. If there's a local one you should try sitting in it as the first move. If you do fit, it should be pretty comfortable. I have no complaints on that front.

All Libelles come with both nose and belly hooks and are draft-free due to a fibre-glass disk, held in place behind the nose hook by hex-head machine screws. Ventilation is generally good provided you don't tape up the 10mm gap between fuselage and lower wing skin just in front of the trailing edge. The tiny adjustable vents on the front coaming do a good job of clearing the canopy and in extremis the front of the canopy can be lifted 30mm in flight, which will instantly clear anything that's not ice.

There's little space for 'stuff'. The stick is mounted on a beam with space under it that I've heard can be used for water, etc. but I've been unable to discover how people secure anything under there. I have a 'saddle bag' with a semicircular cross section that clips on the spars behind my head. Hansjörg Streifeneder (Glasfaser) supplies them. This doesn't restrict the rear view at all. I can still see my fin with it fitted. Having sat in a Std Cirrus once (though never flown one) I can say there's no comparison in rear vision - the Std Cirrus doesn't have much, being similar to a Junior in this respect.

Since the panel fits under the cockpit coaming and is actually ahead of the canopy frame, you can't easily mount PDAs etc. so they stick up over its top. See my panel rebuild page for details of how I've arranged the instruments and the battery box page for ideas on carrying a pair of 12v 7.2 AH batteries in the standard battery box. This last season I've been flying with LK8000 running on a Medion S.3747 PNA mounted on a flexi-mount in front of the panel. This has worked out very well.

I've also fitted an LX RedBox FLARM. This unit is small and light, so I had no problem with fitting it on the instrument tray. The chief problem is where to fit the antenna, which had to be remote from the FLARM because otherwise the upper row of instruments prevented it 'seeing' other gliders lurking behind me. I know of two solutions to this. I'm using the first, which came from Thorsten Mauritsen, a Danish Libelle pilot:

I was able to rearrange my panel to hold the FLARM display, the standard 40mm x 60mm LX Red Box unit, without removing anything and still managed to keep space for a Trig TT-21 display in case we get forced to fit transponders.

Rigging etc.

Nobody runs away if you ask for help rigging or de-rigging a Libelle. It helps a lot that the spar stubs are fully visible during this process. The elevator is self-connecting and the tailplane is locked in place with a single screw. There's a single, central pin that holds the wings together and the airgrakes are self-connecting.

Obviously you'll put the wings on before the tailplane and take them off last, after you've put the fuselage in its dolly and retracted the main wheel.

The only major rigging issue is that the aileron connectors are just inside the fuselage and you MUST feel under them as you drop the spring-loaded center drive pin through the ball bearing on the end of the aileron push-rod. If you can't feel the end of the pin projecting 5-6 mm (1/4") or so through the underside of the bearing or you can feel any movement of the pushrod relative to the drive assembly you've done it wrong: pull the pin up against the spring and reposition the push-rod until the pin is fully through the center of the pushrod bearing. You can't see under there, so use a finger to check that the pin is correctly fitted and sticking out of the underside of the bearing.

The aileron drives are relatively fragile. NEVER, EVER apply any force to the stick if you've got aileron locks on or the wing dolly fitted. For this reason its also better to have the wings off or at least disconnect the ailerons before taking the instrument panel out or putting it back in because doing this needs the stick to be hard over to one side in order to slide the panel past it. Doing this with the ailerons connected and locked will destroy the aileron gimbal drive that's buried in the wing immediately in front of each aileron.

You will probably notice sooner or later is that there are some, fairly rare, circumstances where the wings just won't pull together no matter what you try. This may be because the right wing is slightly out of line with the left one. The trick is to move the right wing's root 3-5mm (1/8"-1/4") forward or aft relative to the fuselage after looking at the position of the lift pin wing sockets relative to the the fuselage pins to see which way to move it. After lining them up the right wing should just slide in when you try the lever again. In my experience doing it this way is faster and easier than getting the person on the tip to move forward or aft until the wing is better aligned. I think this works because the spigots on the spar ends are pointed enough to self-align, while the lift pins, with their blunter ends, are not so tolerant of misalignment.

Support

The type certificates for all Glasflugel gliders including the Libelle are held by Glasfaser in Germany. They're a pleasure to deal with and very helpful if you need spares and/or drawings.

Handling

The Standard Libelle is pretty much a viceless glider. Handling is light and precise with control forces remaining light at all airspeeds up to Vne, though the trim range is minimal on mine. Like most gliders you tend to run out of trim in a steep thermal turn but mine also runs out of trim at the other end of the speed range so I find myself holding the stick forward above 60-65 kts though the forces are still light. Its more a matter of needing to monitor the speed than of noticing you're having to push the stick if you see what I mean. The automatic trim control is a nice touch.

There are only four handling items that need comment:

  1. Weak brakes.
    This applies equally to the first series, which has both top and bottom surface brakes, and to the B series which has top surface brakes only. I've not had problems with land-outs though really small fields could be 'interesting' because Libelles do float further than aircraft with better brakes. Brake effectiveness does vary with speed: while sticking the nose down on finals scrubs off height without much speed increase, they're not doing much toward the end of a fully held-off landing, so raising the nose for a two pointer will cause you to balloon if the glider wasn't ready to sit down. However, they slip really well due to drag from pushing that tear-drop cross-section fuselage sideways.
  2. A tendency to snap-rotate as it leaves the ground on a winch launch.
    This is not mentioned in the glider's flight manual but is easily handled provided that you know about it. I set full forward trim and then push the stick just past the trim's dead band so I start to feel the spring again. The glider lifts off in its ground run attitude and will start to drop its nose as the ASI passes 55 kts if the stick is still where you started the take-off roll, but ease it back before then or as the nose starts to drop and its a pussycat. However, be gentle: if you allow an over-rapid rotation to start, even full forward stick won't slow it down though this rotation stops once the full climb attitude is reached. Once in full climb it handles just like any other glider.
  3. Aileron stalls.
    You may stall the inner aileron in a 45 degree banked turn with a lot top aileron. If the inner aileron stalls it feels a little like an incipient spin but without the nose drop and recovery is the same: the aileron unstalls as soon as you centre the stick. I think its only a problem for the first flight or two: I did it 3 or 4 times when I first got mine, once at the start of the next season and never again since then.
  4. Undercarriage
    The undercarriage retract lever is on the right, so you'll have to change hands on the stick when raising or lowering it, but that's easy enough to get used to. The thing to be aware of is that the handle rotates outward to lock the gear down and has no spring bias to keep the handle in the 'down' detent. This isn't a problem with the gear up as there's no 'up' detent anyway, but when you lower it, be sure to push the handle outward into the 'down' detent: if you don't do this, the gear may sometimes retract on landing. Don't ask how I know this!

Performance

I've never been outclimbed in a thermal in mine, even by Sarah Kelman in a T-21 when she was really coring it. I hear that the Std Cirrus has a better high speed polar and that this is due to flow round the wing root. Glasfaser sell an approved root fairing kit. Mine doesn't have that, but does have a full span lower surface turbulator which seems to help when cruising fast: my SDI C4 seldom shows an L/D less than the Glasflugel figure of 36:1 and the turbulator formerly affected the BGA handicap, so its not just my imagination. There's a set of tiplets available though I've not seen a Libelle with them fitted (only photos) so don't know how much good they do.

All control deflections are fairly minimal. This has no effect in normal flight, but does mean that control effectiveness is low at the start of both aero tow and winch launches. This has no adverse effect on roll rate in flight.

My Libelle is the most spin-resistant single-seater I've flown. I can't spin it from level flight and during the 2010 season, when I was a bit slow pushing over from a zoom entry into a thermal it merely mushed round the first 90 degrees without any hint of wing drop: I'd lowered the nose, of course, and it just picked up speed and climbed away, still circling. It will spin if crossed-up with a nose high attitude. Recovery is normal, though it takes 1/2 a turn rather than the usual 1/4 turn, probably due to the rudder deflection being only 25 degrees.

Distinguishing the H.201 Libelle from the H.201B.

Its difficult to tell when the original H.201 became an H.201B because this took quite a time to do. Here's what I've found out:

Balsa Libelles don't generally suffer from the mysterious inner rottings that bite the ASW-15 though I suppose its possible that the wing skins could be damaged if they've ever been retro-fitted for water since leaky water bags reportedly did for a number of H.301 Open Libelles. A few (including mine) were briefly fitted with Kestrel bags but these were long gone when I bought it.

My wings have no sign of waviness after more than 45 years and a refinish in polyurethane in 1983, but I have no way to know if that is the result of having balsa surfaces or not: my considered opinion as a model aircraft designer and builder is that balsa might make a stiffer, more damage-resistant skin than foam.