DG Flugzeugbau

LS7 – An Often Unrecognized Jewel

by Ludwig Haslbeck (Translation by Albert Tuertscher)
published in the magazin "Segelfliegen" 4/2007

 

With the LS4 Rolladen Schneider could achieve an extraordinary sales success with more than 1000 aircrafts being built.

This sailplane is still favored due to it’s balanced and forgiving flight characteristics, which are valued especially by un-experienced pilots. The performance however is good, but not outstanding, so that this sailplane never played a big role in standard class contests. That’s why the company decided to build a successor which should be absolutely competitive at contests.

A small wing area of 9.74 m2 (104.84 sqft), resulting in a relatively high wing loading, and a low empty weight of about 235 kg (518 lbs) achieved by intensive usage of carbon fiber, are design characteristics of this airplane. Designed in 1987 by Wolf Lemke, the aircraft went into production in 1988, approximately at the same time as the ASW 24 by Schleicher, to which the LS7can be more likely compared not only due to the similar “birth date”, than to the DG-300 or the Discus.

Unfortunately the LS7 could not achieve the big success at contests: although just being second best in glide performance in this class (43 compared to 44 of the ASW 24) she quickly got the reputation of climbing worse in turbulent thermals than her competition. This in fact is true, if one circles with the speed of an LS4 or a Discus. As with the ASW 24 the air flow in this case becomes turbulent, but with a little bit higher speed this can be avoided and the glider climbs considerably better. Also as with the ASW 24 the circling performance could be improved with the usage of winglets in 1991 – but too late to substantially improve the image of the airplane. Therefore the production was stopped already in 1993 after only 164 aircraft built; over a couple of years thereafter used aircraft could be bought relatively cheap. Meanwhile the situation has changed, and the qualities of the aircraft are recognized by pilots who do not necessarily participate at a contest.

Optically typical LS

The LS7 cannot deny her roots: un-mistakenly she belongs to the LS-family, no wonder, as she has the fuselage of the LS6 (except for the LS6 C), which went into series production earlier. Almost the same fuselage is also shared by the LS8 and LS10, which are being produced now in series by DG as successors of the LS7 and LS8 after a long turmoil in connection with the bankruptcy of Rolladen Schneider.

The cockpit seams to be relatively narrow on first sight, but it is very comfortable for pilots who do not exceed  usual dimensions too much, it fits like “custom made”. Relatively little space remains for stuff one wants to have accessible during flight. Here you will have to store things well planned before take-off. All control elements are placed ergonomically and easy to reach. The gear lever is on the right side, the handling is easy and safe. Air brakes are operated on the left side. Typical LS is the operation of the wheel brakes with the heels on the rudder pedals. The T-shaped instrument panel moves upwards with the canopy and such enables easy entering and leaving of the plane, as well as a quick exit in case of an emergency after jettisoning the canopy. The canopy is locked by two long handles on the canopy frame, which are also to be used for jettisoning. The vertical stabilizer contains a water tank to balance the change of the center of gravity when loading water ballast. The tail wheel increases the comfort on the ground.

Weighting about 60 kg (132 lbs) the wings are relieving the pilot’s back during assembly thanks to the usage of kevlar for the ailerons and carbon fiber-sandwich for the wing surface. The airfoil of the double tapered wing is – like at the ASW 24 – remarkably thin. The parentage of the airplane is shown best by the typical circular bent and very large “ears”. The two-fold Schempp-Hirth airbrakes are extended upwards. Both wings have the water tanks in front of the main spar, which are not connected to each other, allowing a water ballast of 50 or 75 liter (13.2 or 19.8 gal).

Not only does the low weight make assembly of the glider easy: ailerons and air brakes are connected automatically, contrary to older versions of the LS6 and also the LS4a. Two main pins are securing the classical fork-tongue-connection. Simple and also typical LS is the assembly of the horizontal stabilizer and fixing with a large knurled nut.

Docile, agile with good performance

I had the opportunity to fly the LS7 of Axel Schneider at Eastern in Belluno on a day with perfect thermals. With normal stature one quickly feels comfortable in the cockpit, all controls are easy to reach, nothing pinches or feels uncomfortable. The take-off behind a 230hp Cessna L19 was without any problems, the ailerons are effective very soon. The view during tow was excellent.
Of course only first impressions can be sampled on just one single flight: 
Most impressive was the enormous agility of the aircraft, especially around the longitudinal axis. Climbing in thermals caused no problems. I was used from my ASW 24 that circling is done best with about 100 to 110 kph  (54 to 59 kn). The LS7 picks up speed very fast if the stick is pushed forward. The ventilation did impress me less, it was overall to weak. In return the noise level was lower. The landing caused no problems, the approach could be very well controlled by the effective air brakes. My first impression:
The LS7 is an easy to handle, very agile airplane, whose performance does not need to hide from the next generation.


Pilot Opinion

Axel Schneider, who flies a lot in the, decided two years ago to sell his DG-300 to buy a model with higher performance.

segelfliegen: Axel, what should the new plane offer more than the DG-300?

Axel: Important for me was better gliding and speed performance, as the 300 was doing anyhow fine in climbing. On the other hand the better performance should still be affordable. And of course I didn’t want to do without the comfort of the 300 with automatic hook-ups. Additionally the airplane should be low on hours.

segelfliegen: Which planes did you take into consideration?

Axel: In the standard class it was the Discus and the ASW 24, in the 15m-class the LS6, which with the exception of the LS6c, had no automatic hook-ups. Furthermore the LS6 is traded at high prices.

segelfliegen: Why did you end up with an LS7?

Axel: The asked prices for available Discus were quite high, in addition most of the airplanes which were available back then had a whole lot of hours. With the ASW 24 I had problems with the seat bowl, but later I learned that different versions are existing. Depending on your body height you have to be careful here. The LS7 fit me right from the beginning. Of interest is also the index of 106, the same as the DG-300.

segelfliegen: How was the market for the available airplanes and which prices were asked for?

Axel: Back then some Discus were on the market, a few ASW 24 and a few LS7. LS7 and ASW 24 were sold between 32.000 and 38.000 EUR, the planes having winglets or not made a significant price difference.

I made a find at a club, who sold me their LS7 with barely 1000 hours, but without winglets. If you want winglets you should buy an airplane with this feature, as the upgrade is an unaccountable financial risk, as I had to experience myself. The reason was that the winglets were delivered in a relatively bad shape, and the correct fitting was difficult, time consuming and thus expensive.

segelfliegen: Which experiences did you have so far with the LS7?

Axel: The first year I flew without winglets, there were problems when I was flying with water. In this case the airplane was climbing relatively bad. Other than that I was excited about the gliding performance, especially in the upper speed range. Final approaches over 70 kilometers (44 miles) with comparable or even better airplanes didn’t show much of a difference.

Excellent are also the handling and flight characteristics: the LS7 is absolutely docile, the rudder coordination fits, the airplane is very agile. Especially to be pointed out is the ease of movement of the ailerons. A difference to the DG-300: you have to circle a bit faster, especially at steeper circles, because then the machine climbs better. The LS7 is also a comfortable airplane, despite the cockpit being relatively narrow one sits very well, also the suspension of the gear is excellent. Be careful when braking, due to the main wheel being located far behind the airplane tends to get on its nose quickly. Also the wheel could be a bit larger. The ventilation is not quite optimal. All controls within the cockpit are well accessible, the view is also good. I could fly my plane with winglets now for about 35 hours, she’s circling now even nicer and calmer, but lost a bit agility. Meanwhile I also flew the LS7 with water: up to 60 liters (16 gallons) is ok, with more ballast she climbs worse.

segelfliegen: Would you buy the LS7 again?

Axel: Concerning the flight characteristics in any case, but after the bankruptcy of LS the spare part supply might be a bit more difficult than with other planes. But in this case comprehensive cover insurance can help to offset the higher costs in the case of a repair. 


Dealer Opinion

We asked Hannes Zimmermann, International Sailplane Service, about the market for this airplane.

segelfliegen: Mr. Zimmermann, how is the market for this type?

Hannes Zimmermann: There are only few machines offered, however the demand is good. This is based on the fact that the image of this airplane, which was “killed by mouth” at the beginning, has meanwhile improved considerably and the good performance is now valued.

segelfliegen: What is the price range for the LS7?

Hannes Zimmermann: It is only a bit below of the ASW 24 and the Discus, which are still traded highest in this class. For a good LS7 one should be able to achieve 32.000 EUR to 35.000 EUR.

segelfliegen: On what should you pay attention with the LS7?

Hannes Zimmermann: Principally those are things which are valid for all LS-planes, like the gear dampers, which fatigue over time, or paint problems, which many airplanes from this manufacturer have.


Spare Parts Supply

For spare parts supply segelfliegen asked Holger Back from DG-Flugzeugbau. This company took over type certificate holdership for the LS7 after the bankruptcy of Rolladen Schneider. According to him all usual spare parts are still available. Of advantage is further that the LS8, which is still under production at DG, shares many parts with the LS7. Problems occur with a damage of the wing or aileron. The forms for these are no longer available, here one has to try to find used parts. DG also performs retrofitting of front tow hooks or winglets. These cost including installation about 3000 EUR.

 

LS8 and LS6 15/18m Glider
3-side view

 

Spare Parts

Type certificate holder:

 

DG Flugzeugbau GmbH
Otto-Lilienthal-Weg 2 / Am Flugplatz
D-76646 Bruchsal

Phone: +49 (0) 7251 3020-0
e-mail: info@dg-flugzeugbau.de
internet: www.dg-flugzeugbau.de
Previous Manufacturer:
Rolladen-Schneider Flugzeugbau, Egelsbach