Helicopters can fly in the rain as long as Visual Flight Rules (VFR) or Special Visual Flight Rules (SFVR) are met. These rules govern the operation of aircraft in Visual Meteorological Conditions. However, even if a helicopter is authorized to fly in the rain or in any other less than ideal conditions like snow, sleet, and fog, a pilot may want to avoid doing so anyway.
Some people believe that helicopters are unable to fly in the rain because they heard that Marine One, which is the call sign of any United States Marine Corps aircraft carrying the president of the United States, was grounded during bad weather.
This isn’t because helicopters aren’t able to fly in the rain, but actually because the President’s safety is far more important than flying with the increased risk that questionable weather conditions can cause. Very conservative weather minimums are therefore adhered to.
3 Factors That Determine if a Helicopter Can Fly in the Rain
Visual Flight Rules (VFR)
According to 14 CFR 91.155, which is the regulation that determines Basic VFR Weather Minimums, a helicopter is allowed to fly during the day when there is at least 1/2 statute mile of flight visibility. At night, flight visibility of at least 1 statute mile is required.
Therefore, even if it is raining, as long as a helicopter pilot’s flight visibility meets the above minimums, they are authorized to fly.
Special Visual Flight Rules (SFVR)
Under Special Visual Flight Rules, a helicopter is allowed to fly when flight visibility is below 1 statute mile, and take off or land when the ground visibility is below 1 statute mile.
However, this is only in the case provided Special VFR clearance is requested by VFR pilots, which is then either authorized or denied at air traffic control (ATC)’s discretion.
Tolerance for Risk
Even if the weather minimums say it’s okay for a helicopter to fly in the rain, it’s always better to be safer than sorry. There have been far too many fatal helicopter crashes that could have been avoided if a pilot simply waited for the conditions to improve.
It can be understandable that a pilot and/or the passengers need to be somewhere at a certain time and feel that there is very little danger that something bad will happen during the flight. After all, no one really thinks something as bad as crashing is going to happen to them until it actually does. It is also understandable that it can be very hard for a pilot to be firm and refuse to fly if their employer is insistent that they should.
However, when it comes to flying, whether that be in an airplane or helicopter, the rule is that any tolerance for risk should be low. It’s far better to be safer than sorry, even if it means that there is a delay.