Takeoff in car tow this is a much desired option for pilots of Antares 18T and Antares 23T, as it allows for even more independence for these aircraft with home return assistance. The first extensive test launches in aerotow with the Antares 18T have shown that this type of launch can be a useful addition to winch launching or aerotow. Now we have continued the testing of car towing in Reinsdorf near Berlin with an Antares 23. It should be investigated whether the Antares 23 in car towing can still reach altitudes from which it can continue flying independently, even with full water ballast. After all, the 23 weighs almost a ton with full tanks. The data obtained during the test will also be used to verify our mathematical models of auto-tow launch for large flight masses.
Since the maximum flight mass is identical for the Antares 23T and the Antares 23E, it was possible to use an Antares 23E that was just available for testing. Unlike the flight test with the Antares 18T, the engine remained in the fuselage during testing of the 23. For certification, the aircraft had to be flown up to the maximum permitted speed for winch launch – which meant well beyond the operating range of the engine. It was found that greater disengagement heights were achieved with increasing towing speed. During the first flights with a take-off mass of 642 kilograms, i.e. without water ballast, and with flaps set to +1, an altitude of around 280 meters was achieved at a towing speed of 140 to 150 km/h. The aircraft was then flown at a speed of 1,000 km/h. The first flights were also performed at a speed of 1,000 km/h. At 160 to 165 km/h, it was as much as 300 meters, and that was with a 20 to 30 km/h headwind coming from the side at about 30 degrees.
A 258 hp BMW 530d Touring with all-wheel drive was used as a towing vehicle during the test flights on the grass field, which was a good two kilometers long (we did not use the full length of about 2,800 m). The dyneema rope used had a length of 370 meters. The flights with full water ballast – the Antares 23E then weighs 901 kilograms – resulted in significantly lower release altitudes. Takeoffs at about 140 km/h towing speed ended at 200 meters altitude, tows at 145 to 155 km/h at about 250 meters. This meager altitude yield speaks rather against the car tow launch with the 23 with water ballast. Steering in the tow was similar to that in the winch launch and brought no surprises. The steering forces to be applied were low. Also, no large deflections were required to keep the surfaces horizontal from roll-on. Also, with a slightly tail-heavy trim, there was no particular need to push during the climb. With the flights we have noticed: The Antares 23E takes off at 70 to 80 km/h. Further, the speed increases when a significant climb attitude is assumed. In this phase it is important that the tow vehicle continues to accelerate above 90 km/h, otherwise the pilot must be careful not to adopt too large a climb angle, as in the winch launch. Safe and effective takeoff becomes with airspeeds from 120 km/h. The car has to accelerate to around 110 km/h for this. Of course, with a corresponding headwind, a lower speed is sufficient. For the tests, the Tost coupling was used again, which can be mounted on trailer couplings without any effort. Now the certification of the Antares for the take-off mode autotow is pending. In order for it to be used, pilots need to have the auto-tow license entry and airfields need to include the auto-tow takeoff type in their permit.