Based on the probabilistic approach and using the extreme value distribution (EVD) technique, we address the helicopter undercarriage strength in a helicopter-landing-ship (HLS) situation. Our analysis contains an attempt to quantify, also on the probabilistic basis, the role of the human factor in the situation in question. This factor is important from the standpoint of the operation time and, hence, from the standpoint of the likelihood of safe landing during the lull period in the sea condition. The operation time includes the time required for the officer-on-ship-board and the helicopter pilot to come up with their go-ahead decisions, and the time of actual landing. It is assumed, for the sake of simplicity, that both these times could be approximated by Rayleigh’s law, while the lull duration follows the normal law. Safe landing can be expected if the probability that it takes place during the lull time is sufficiently high. The probability that the helicopter undercarriage strength is not compromised can be evaluated as the product of the probability that landing occurs during the lull time and the probability that the relative velocity of the helicopter with respect the ship’s deck at the moment of the encounter of the undercarriage with the deck does not exceed the allowable level. The developed model can be used when establishing the requirements for the undercarriage strength, as well as when developing guidelines for personnel training. Particularly, it can be employed for establishing the times that need to be met by the two humans involved to make their decisions for landing and to actually land the helicopter in a timely fashion. It goes without saying that plenty of additional risk analyses (associated with the need to quantify various underlying uncertainties) and human psychology related effort will be needed to make such guidelines practical.