Pee among the clouds on the way to bomb Iran: the secret of the F-35 pilots is revealed

In the field of aviation medicine, we are very familiar with the phenomenon of “Tactical Dehydration”. For decades, pilots used to avoid drinking long hours before takeoff so as not to need the bathroom during the flight. However, this is an extremely dangerous practice. Dehydration, even a slight one, leads to a decrease in plasma volume and venous return, which causes a dramatic decrease in resistance to G forces. A dehydrated pilot is at least 50% more likely to suffer from G-LOC, a temporary loss of consciousness caused by a lack of oxygen supply to the brain during a sharp maneuver. In addition, a lack of fluids harms cerebral perfusion and causes a significant cognitive decline, impairment of reaction time and narrowing of the field of vision – phenomena in the cockpit of a fighter jet at supersonic speed can be devastating.

In the United States, the realization that the pilot’s health is a critical component of the aircraft’s lethality led to a technological revolution that was officially recognized in 2025. The leading system currently in the US Air Force (USAF) for F-35 pilots is the Skydrate. It is a completely automatic and wearable pumping system that eliminates the need to use hands. The system consists of a dedicated end accessory, a sort of collection cup for men or a technological pad for women connected to a fluid detection sensor and a small electric pump. As soon as the pilot starts to urinate, the sensor detects the liquid within milliseconds and activates a vacuum pump that sucks the urine through a thin tube built into the overalls. The liquid is transferred to an external collection bag that is usually located on the shin or in a designated pocket in the flight suit. The system runs on rechargeable batteries with a USB-C connection and allows the pilot to continue flying the plane, control the stick and throttle and manage the mission without looking away or performing any physical action.

On the other hand, in Israel and in many units in the world that have not yet implemented the pumping systems, the accepted solution remains the “Piddle Pack”. These are durable plastic bags that contain a chemical absorbent material (Super Absorbent Polymer) that turns the urine into a solid gel and prevents leaks. The use of these bags in the cockpit of the F-35 is a complicated logistical challenge due to the density of the cabin and the advanced harness system (QRB) that locks the pilot into the ejection seat. Trying to use a carry-on bag during an operational flight requires a high level of concentration and considerable physical maneuvering, which can sometimes lead to a loss of spatial orientation.

The process of using the urine bag during the flight, step by step, looks approximately like this. First, the pilot must make sure that the plane is in stable flight and in autopilot mode, carefully scanning the airspace and the radar systems to make sure there is no immediate threat. In the second step, the pilot is required to slightly loosen the safety straps and harnesses that fasten him to the chair, an operation that requires complex movements under the limitations of space in the cabin. In the third step, the pilot must locate the bag stored in the pockets of the overalls, unzip the flight coveralls and suit the assembled G, and insert the bag into the appropriate position. In the fourth step, while maintaining eye contact with the instrument monitors, the chemical crystals inside the bag immediately react with the liquid and turn it into a solid mass. Finally, the pilot must close the bag with the ziplock, zip it back up and re-tighten the harnesses. full combat.

The risk of manually using these bags is not only sanitary or physical comfort. There have been cases in aviation history where fiddling with the urine bag distracted the pilot at a critical moment, or a leak of urine caused a short circuit in the sensitive electronic systems located on the cockpit floor. In the F-35, where all systems are connected and based on advanced computing technology, any fluid leak is a serious safety event. In addition, prolonged restraint causes an increase in blood pressure, abdominal pain and mental stress that reduce the pilot’s concentration, which leads to human errors.

The transition from cumbersome manual systems to automatic pumping systems in the US marks the end of the “tactical dehydration” period and paves the way for improved performance and better health for the fighters. For the fighter pilot, the ability to drink enough water without fearing the moment he will have to evacuate is the real tactical advantage that allows him to remain sharp, focused and lethal until the moment of landing.