## 4 Case Study  
Based on a strategic decision-making process of BN in acquiring new attack helicopters to support its operations, a multi-criteria evaluation by the PROMETHEE-SAPEVO-M1 modeling is carried out. To make the present study feasible, providing analysis as close as possible to the reality, we used the support of stakeholders present in tactical and strategic combat operations concerning the employment of helicopters of attack. For this evaluation, three officers of the Brazilian navy were consulted, one being a combat operations commander and two aviators. The alternatives chosen are among the most used helicopter models in the armed forces worldwide, with recognized effectiveness in military missions. In the sequence, all helicopters under analysis are described:  
* AH-1Z VIPER (BELL): Built to meet the needs of the United States Marine Corps (USMC), being used by this force since 2009. Due to the USMC operating in various environments, mainly at sea, this aircraft has been specially developed to withstand the maritime weather [79];
* T129 ATAK (Turkish Aerospace): Manufactured by Turkish Aerospace, the T129 ATAK was developed to meet the needs of the Turkish Armed Forces. It is a twin-engine attack helicopter, optimized for carrying out attack missions, armed reconnaissance, and precision attacks under various weather conditions and during day and night periods [80];
* Mi-35M (Russian Helicopters): Currently manufactured by Russian Helicopters and primarily developed by Mil Moscow Helicopter Plant, it is an attack helicopter that has its size as a differential, as it has relatively higher weight and dimensions than an ordinary attack helicopter [81];
* Ka-52K Katran (Russian Helicopters): Version designed to operate in the naval environment of the Ka-52 Alligator, produced by Russian Helicopters. It is a state-of-the-art reconnaissance and combat aircraft aiming to destroy armored and unarmed ground targets, troops, and enemy helicopters on both the front line and tactical reserves [81];
* Tiger HAD (Airbus): A multifunctional attack helicopter, which aims to conduct armed reconnaissance, air-to-ground escorts, air-to-air combat, air-to-air support, and attacks on armored targets on land, day or night and in harsh conditions [82];
* AH-64E APACHE (Boeing): One of the world's best-known attack helicopters, the AH-64E APACHE, produced by Boeing, is widely employed by several armed forces, such as the United States Army, Egypt, Greece, India, Indonesia, Israel, Japan, Korea,Kuwait, the Netherlands, Qatar, Saudi Arabia, Singapore, the United Arab Emirates, and the United Kingdom [83];
* Sikorsky S-70 (SIKORSKY): It is a helicopter capable of operating anywhere on the globe, whether in cold or high-temperature regions, thanks to its configuration and power reserve. Its essential mission is troop transport. Containing equipment that allows performing the flight by instruments, this aircraft is configured to enable the flight with night vision goggles [11];
* H215M (Airbus): Operated by the Brazilian Army, it is fit for employment in combat missions, combat support, and logistical support. It has several optional equipment and accessories, including 4.5-ton hooks, a 272 kg winch engine, and six stretchers for aeromedical evacuation [11];
* H160M (Airbus): This helicopter can be reconfigured in a fast way to perform missions ranging from commando infiltration to air intercept, fire support, and anti-ship warfare; up to two stretchers for search and rescue operations; as well as a fast rope system, cargo hook, and hoist, that is used equally for public missions--a versatile, all-in-one asset for modern militaries [84]. The helicopters were evaluated in light of operational and tactical criteria. It is fundamental to highlight that, after consultation with the officers and helicopter manuals, quantitative and qualitative criteria were considered relevant for the proposed analysis.