Characteristics of air-shower-triggered atmospheric families detected in the hybrid experiments together with emulsion chamber and As-array at high mountains are compared with those of simulations. The analysis of families accompanied by air-showers with N(e) >= 10(7) shows that the experimental family-energy distribution favors a proton-dominant chemical composition of primary cosmic-rays but the lateral distribution favors a heavy-dominant composition. Thus no simulations can describe the overall characteristics of the data of hybrid experiments.

The Ne spectrum of extensive air showers at Ten-Shan (experiment HADRON) is analyzed. It is shown, that around 10(17) eV a bump is observed in the spectrum. A sharp break in the spectrum at 3 PeV and the bump at 100 PeV are interpreted as an additional CR component, caused by the radiation from one or two close CR sources. It is noticed, that the mass composition of the basic CR component and the additional one can differ.

At the last Symposium it was the view that the problem of the knee in the CR spectrum is practically solved and does not demand further experimental investigation. A frequent basis for this opinion is the simulation dependent procedure of extracting the information oil the CB. mass composition. This report is a survey of the experimental data which contradict such a point of view. These data point to the restricted self-descriptiveness of some EAS installations and show the shortcomings of some processing methods. Therefore, not looking to continue research for another 50 years, we present a solution to the problem of the knee.

Characteristics of the air-showertriggered atmospheric families detected in the hybrid experiment together with emulsion chamber and AS-array at Mt. Chacaltaya, Tibet and TienShan are studied in detail by comparing with those of CORSIKA simulations using interaction models of QGSJET, SIBYLL and EPOS. In the Chacaltaya data, family-energy distribution in the events with air-shower size of Ne ≥ 107 is favorable to heavy-dominant chemical composition of primary cosmic-rays but the lateral distribution is favorable to heavy-dominant composition. The Tien-Shan data, however, energy and lateral characteristics of the EAS-triggered families are not much different from those expected in simulations using QGSJET and EPOS models.