In 2001 Euroavia Toulouse organized a symposium on ground effect. We invited most of the Russian and German actors, and some experts from Holland, UK or France for a week of science around the subject of ekranoplans / flying boats. This was dedicated to students. A book was issued... and now that all copies have been sold for a while I am sharing this on LinkedIn for everyone. Enjoy. Stéphan AUBIN

1. Flight Testing of the Hoverwing
Prepared for the EAGES 2001 International Ground Effect Symposium
Toulouse, France
June 2001
Hanno Fischer
Fischer - Flugmechanik
Kickenstraße 88
47877 Willich / Germany
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3. Flight Testing of the Hoverwing
Hanno Fischer
ABSTRACT
The second generation of Lippisch ground effect configuration is currently under development
at Fischer Flukmechanik. The development of a full size prototype, the 2-seater HW-2VT proved
the concept of the Hoverwing technology to be an efficient and economically viable solution for
take-off.
In this paper are presented the requirements for the Hoverwing 80-seater from the German
authorities as well as some of the results and methods that permitted the validation of the concept.
ABOUT THE AUTHOR
Ing.Hanno Fischer was the Technical Director to Rhein- Flugzeugbau GmbH (RFB)in Germany.
He has developed around 12 different aircraft like Fantrainer, Fanliner, RW 3 and the military used
WIGs X113, X114 and X114 H (X114 with hydrofoils) .They were designed as aircraft to fulfil the
military requirement with free flight capability. The concepts were based on the works of Dr.
Lippisch.
After retiring from RFB he founded the company Fischer - Flugmechanik together with his
partner Klaus Matjasic. Their target is to develop the ground effect technology towards commercial
application.
Based on their patents, they successfully designed the first generation of WIGs for civil use-
the Airfisch 1, to Airfish 3, for which they granted a production licence to RFB.
In order to achieve a higher economical efficiency, they have developed the Hoverwing techno-
logy, which can be considered to be a basis for the second generation of WIGs. Their works are
government sponsored from the German Ministry of R&D.
Last design is the Airfisch 8 called now Flightship 8, a 8 seater which has made the maiden
flight in February 2001 and is delivered to Australia after successful flight demonstration.
Author of many articles and papers in the field of ground effects, for instance in Australia 1996.
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Base of Experience in Wing in Ground Effect Craft
Manned Aircrafts
X-113 Single seat military test craft 390 kg
X-114 Six seated military test craft 1800 kg
X-114 H Take-off aid with Hydrofoils 1800 kg
Manned Boats
Airfish 1 Single seat airfoil boat 390 kg
Airfish 2 Modified airfoilboat 600 kg
Airfish 3 A Two seats airfoilboat 760 kg
Airfish 3 PA Power Augmented 950 kg
Airfish 8 (Flightship 8) 8 seats 4310 kg
Hoverwing 2 VT 2 seats 1150 kg
Model Testing
Wind Tunnel Tow Tank
Radio Controlled Free Flight Circular Control Line
Lippisch Airfoil Boats Airfish Variants
Tandem Airfoil Boats Hydrofoils
Static Air Cushion Hoverwing Technology
Theoretical and Experimental Research
DFVLR G¨otingen / Braunschweig
Institut Luft- und Raumfahrt University Aachen
Vesuchsanstalt f¨ur Binnenschiffbau VBD

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Demonstrator Hoverwing 20/3
Weight
Empty Weight 6534 kg
20 Passengers + 20 kg Baggage 2000 kg
Useful load 2460 kg
Take-off weight 8994 kg
Dimensions
Length 20.98 m
Width 20.00 m
Height 4.94 m
Cabin Length 6.20 m
Cabin Height 1.8 m
Cabin Width 5.0 m
Performance
Range (no Reserves) 500 km
Endurance 3h
Cruise Speed 175 km/h
Cruise Height ≤ 1.75 m
Take-off Speed 126 km/h
L/D 18
Cruise Power 465 PS
Figure 4 : Hoverwing 20

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Characteristics of Airfoil Boats
Automatic Height Stability
”Hands-off” Cruise
No pilots licence or pilots experience
Jump Capability
High Manoeuvrability
Short Turn Radius
Short Landing Distance
Flaring over Ice, Snow, Sump
Compact Dimensions vs. Aircrafts
Lower inspections costs than Aircrafts
Capsize Proof
No Sea Sickness
High Comfort due to Boat-like Volume
Limitation of Take-off and Landing (Sea state vs. Scale)
Figure 7 : Hoverwing 80

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Preliminary Results of the Comparing Tests with Hoverwing VT
Recommended
by Test Scaled
Performance Results to RESULTS
Specification HW-80
Scale 1 : 1 1 : 3.35 1 : 1
FLARE MODE
Inherently yaw stable 0 0 0 proven
Inherently height stable
up to : 3.5m 1.5m 5.0m proven
Inherently height stable
up to : b/2 b/4 b/4 pending
Radius for 90 degrees turn ≤ 1000m 280m 938m proven
TAKE-OFF
AND LANDING
Take-off distances ≤ 1500m 430m 1440m proven
Take-off at wave height 1.5m 0.55m 1.85m significant
better
Landing at wave height 1.5m 0.6m 2.1m significant
better
Landing at wave height 2.5m often often pending
Stop distance from cruise ≤ 1000m 200m 670m significant
better
Emergency stop distance 400m 120m 402m almost
proven
ECONOMICAL TEST
RESULTS
Glide Ratio 12 13 13 proven
Speed 180km/h 110km/h 200km/h significant
better
Installed Power kW/to 150 59.2 118 proven
Fuel Consumption
gr
PAX.km
40 cruise 37 proven
30.3 kW
MISCELLANEOUS
Maximum Take-off Weight 30 214kg 1 065kg 40 040kg significant
better
Maneuvering
in displacement under wind 0 0 0 failed
Weight to Thrust Ratio - 6.4 6.4

15. Hanno Fischer Flight testing of the hoverwing 209
Results of the Sea Trials with Hoverwing 2-VT
1999 - 56 take-offs 6h29min flight time 725km flown
TOTAL - 127 take-off 24h36min flight time 2700km flown
MTOW 1 180kg Useful load : 310kg
(Max. Take-Off Weight) (2 seats and ballast)
CG Range 2.777mm ↔ 3.218mm =12 % chord
Take-off time Single seated 24sec
2 seated 43sec
Reduction of Lateral area improved manoeuvrability
Turn Radius diametre : 600m
Obstacle avoidance with 50 m at 125km/h
from 170m
Take-off Power 85kW Minimum : 38kW
Maximum Speed 135km/h
Cruising Speed 110 km/h at 53kW
Minimum Speed 95km/h at MTOW
Height up to 1.9m constant
Hands-up More than 4 minutes at constant height
Testing in Landing with Tailwind
Dangerous Situations 1m wave height
No Structural damages

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HW-80 Dynamic testing
Jump
Figure 9 : RPM
Figure 10 : Speed
Figure 11 : Height
Figure 12 : Angle of attack
Figure 13 : Elevator

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Landing
Figure 14 : RPM
Figure 15 : Speed
Figure 16 : Height
Figure 17 : Angle of attack
Figure 18 : Elevator

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DISCUSSION
Mario Mihalina (MM), Euroavia Zagreb
I have a question about emergency again. Imagine that your craft has to make a jump. What can
happen is that the craft rolls to much and crashes during the jump.
Hanno Fischer (HF), Fischer Flugmechanik
You are right if the craft makes the jump with a high angle of attack because then you take the
risk that one of the wing can stall and then what you described happens. But with the direct lift
control system that we have, the craft maintains at a constant pitch angle, we do not have the risk
of any stall. Anyway our aspect ratio is quite small and for airplanes it is known that the risk you
describe is larger when the aspect ratio is bigger. So I would say that the risk is really limited.
Chairman Allan Bonnet (AB), SUPAERO
Another question following this question. You make a jump over a boat but you discover that
behind this boat there is a second one. Can you make several jumps ?
HF
Not too many ! But you have the chance to make a turn. Jumping is not something that you do
regularly. This is a chance to minimize the chance of collision.
Graham Taylor (GT), Independent Consultant
First of all, Mr Fischer, let me say very great thanks for presenting an excellent presentation that
brings together theory and practice. I would like to make a few comments related to my flying
experiments with models. Your direct lift control is very difficult to achieve on anything else than
a Lippisch layout because for example on an ekranoplan layout like I use in my models, the only
place where you can use a flap is at the trailing edge and doing so, you change the pitch angle for
any use of this flap.
HF
With your configuration, with a flap on the rear, if you deflect a flap, you will change the moment
of the wing and the lift distribution. On our craft, we have a forward swept wing and the lifting
line is at 50% between the trailing edges of the inner airfoil and the outer airfoil so we have a
balance of the flap effect. It can work only with this kind of forward swept wings.
GT
That was exactly the point that I wanted to mention. I do not know if you remember but I
tried something equivalent on one of my models, the Mk 6 which I showed a picture of in my
presentation1
. The holes would serve to mimic your system. . .but I do not expect it to work as well
as half of your own.
1
Page 153, Figure 13. The Editor