ZEL is a cold war proven method for launching the aircraft. The system becomes bulky to carry around with larger aircraft but the future is a2a light jet drones. They can be towed around more easily. It can be experimented with converting the retired Mig-21 or F-7pg to experiment for that role and even dronizing them. In cold war it was planned for second strike capability and heavier aircraft. Light a2a loaded aircraft would be more easier to launch.
Another way of launching is dolly launch. It was also used extensively in WW2 german rocket aircraft/jet Me-163 and Arado-234. Also notice at the end it lands by landing skids.
One problem with dolly launch is the jet engines of modern aircraft are prone to debris on the unprepared-ground-grass runway. Mig-29 has foreign object blocking option closing the inlets below the aircraft and breathing air from top of the aircraft while taking off and landing. Another solution can be the aircraft would stay angled looking up while taking off from the trolley. If the nose is slightly looking upwards on the trolley there is less chance of debris coming inside the engine inlet. In that case the engine nozzle should be directed a little upwards to not to dig through the runway while taking off and then engine nozzle should be leveled while in flight. If the aircraft is light or a drone version it would be easier in my opinion. If the intakes are not under the fuselage like F16 and if the plane has Y intake or side top intakes it would be easier to take off with a dolly-trolley.
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Landing is a different and more difficult issue.
*Vtol is hard to implement and requires an extremely powerful engine. Double engine also has problems to adjust the airflow so they are mostly if not all single engine aircraft with possible risky vertical jets yak-141 or ducted fan engine on the front like F-35. The plane would be designed for vtol and other required concerns like stealth would be more expensive in design and production as well.
* Landing skids were used in ww2 aircraft like me-163 and Arado-234. It would be somewhat hard to install retractable versions on stealth a2a drones-fighters. But if the drone is light retractable landing skids can do the job in my opinion for rough landings.
Sud-Est S.E.5003 Baroudeur also used landing skids. Rough landing wont be a problem for unmanned aircraft and stealth wont be compromised if its is retractable landing skids.
* Ultra long highways can be more easily repaired and can be used for landing if not taking off and carrying aircraft to launch locations by ZEL or towed Trolley-Dolly. It would be difficult te determine the exact used location by spy satellites-pictures and attacked part can be repaired while other portions are used for landing.
* ZEL was first intended with Mat landing. It was called ZEL-MAL. Inflatable very large mat is carried around to the landing location. Then can be carried to somewhere else in scoot mode to not to be targeted. Arrestor hook was used for landing on the inflatable mat. Landing was successful but there were problems. The pilot was injured from rough landing which can easily be overcome for future aircraft since they would be drone versions with no pilot issues. The mat was damaged which can be overcome with current materials and the nose of the aircraft pierced through the mat while landing. This can be overcome with some airbags opening under sharp points of the aircraft while landing on the mat in my opionion.
