What do you mean they went inadvertent

Flying Safety, July, 2003 by Michael K. Phillips

"What do you mean 'They went inadvertent IMC'?"

As the unit Safety Officer, that was my response when I heard one of our crews had "punched in." Of all the times for it to happen, it occurred during a deployment to Bosina, over mountainous terrain and at night, while wearing NVGs. If that wasn't bad enough, the flight was a medevac mission with a patient on board, and the two pilots had about 800 flight hours combined. (The pilot-in-command did have some additional civilian flight experience and is considered one of the more squared-away PICs in the company.)

I used to consider inadvertent IMC (IIMC) as a "self-induced emergency caused by pilot error." For the most part, I still think that's true. But I guess there are times when you just cannot see the clouds. Or, if you're wearing NVGs, by the time you realize you're in a cloud, it's too late to continue VMC.

I never gave IIMC much thought until that day. We're not supposed to do it, we have procedures in place in case we do it, and nobody ever does it. So why worry about it? I've been in Army aviation for more than 11 years and had never been in a unit when a crew had gone IIMC. This perfect track record had lulled me into a false sense of security. It allowed me to think it couldn't happen, or wouldn't happen. Not on my watch, anyway.

Why would it happen? We train our crews to avoid it at all costs. We tell them over and over, "Don't attempt to fly VFR in IFR conditions. It's dangerous." We've all seen the Safety Center posters showing the catastrophic results. If weather is bad, don't fly. If weather get bad, turn around and go back, or Land where you are and wait it out. Or, if you are trained, equipped, prepared and proficient for IMC flight, request an IFR clearance from ATC and continue the mission IMC. (That last option may not always be available in Bosnia, or on other deployments, based on local NAVAINDS and instrument approaches.)

Have we all been lulled into a false sense of security? We've all heard the old pilot joke: "If it's too bad to go IFR, we'll go VFR." To avoid going IFR, many of us have gone "scud running." A Federal Aviation Administration publication defined scud running as "pushing the capabilities of the pilot and the aircraft to the limits by trying to maintain visual contact with the terrain while trying to avoid physical contact with it."

I've had several encounters with deteriorating weather while flying VFR. There have been many times when I simply turned around and went home. On a few occasions, I radioed ATC and received an IFR clearance so that I could continue the mission IMC. But, I've never gone inadvertent. I've turned down countless missions (including medevac missions) because of poor weather. Somehow it's easier to refuse a mission while standing in the flight operations office, compared to refusing to continue to fly a mission while in the air. We all want to succeed in our mission, especially if that mission is to save a life.

There are times when a patient's only hope of survival may be via a flight on an Army helicopter. Air ambulance units, like the one I'm in now, are frequently called upon to fly in poor weather and at a moment's notice. All too often, Dustoff crews will fly a medevac mission in weather that they wouldn't even consider on a training flight. (Been there, done that.) The desire to succeed can easily turn into a perceived pressure to complete a mission, particularly a medevac mission. That pressure is almost always self-induced and is felt by pilots and even non-rated crewmembers. Commanders will always support crews that turn down missions for safety reasons.

According to an NTSB study, unplanned entry into IMC is the single most common factor in fatal emergency medical service helicopter crashes. Because most of the IIMC accidents result in pilot fatalities, accident investigators are able to learn little about the events that led to the accidents. In cases where pilots lived to tell their story, it's like the Safety Center has been telling us all along: The pilots tried to fly VFR in IFR conditions. They also felt pressure to accomplish the mission, in spite of deteriorating weather conditions.

Fortunately for those of us in Army aviation, there are established procedures in place that prepare us in the event that we do go IIMC (Air Force has those, too. Ed.). We brief IIMC procedures with the crew prior to every flight. The Aircrew Training Manual (ATM) clearly states, step-by-step, what to do after encountering IIMC. Local standard operating procedures (SOP) also provide guidance in case we accidentally punch in.

On this night when our crew went inadvertent, they did everything by the book, just like they were taught. The PIC briefed IIMC procedures to the crew prior to the mission. The pilots obtained a valid weather briefing and had even updated it just prior to takeoff. The PIC had the only available instrument approach procedure open and strapped to his kneeboard, and approach control frequencies were set in the radios. (The weather forecast called for better-than-VFR conditions, but proved to be incorrect.)