For helicopters, that is.
Tomorrow, I’ve got a lengthy charter booked with a new client. It’s an animal survey mission, which will likely require me to fly low and slow over varied terrain. The job’s starting airport is at 5,600 feet, so the whole job will be at high density altitude. Fortunately, there’s just two of us on board, so power shouldn’t be much of an issue.
Unless the wind becomes one.
When I checked the weather on Saturday for Tuesday, it was forecasting winds 12 to 24 mph with gusts up to 37. I imagined myself battling a 13 mph gust spread with a tail wind when I was flying at 40 to 60 knots. It wasn’t a pretty picture.
I e-mailed the client and suggested that we move the flight up to today (Monday) or earlier on Tuesday, before the wind kicks up. I knew he was traveling, so I figured I’d follow it up with a phone call later in the day.
When I checked it again last night, the winds in that area had dropped considerably and forecasted gusts were only 25. That was more reasonable. I called the client and left him a voicemail message on his cell phone, explaining the situation and offering to change the date and time, but not making it seem so urgent.
This morning, the forecast is as follows for tomorrow in the flight area:
Sunny, with a high near 72. South southwest wind 7 to 10 mph increasing to between 15 and 18 mph. Winds could gust as high as 30 mph.
I sure wish the National Weather Service would make up its mind.
So the question is, how much wind is too much wind to fly?
My Experience with Wind
Although I liked (and still like) my primary flight instructor very much, there were two things he “babied” me on in initial training:
- Radio work. I was crappy on the radio — which is odd, considering how well I can let my mouth run when around family and friends — and he made it a non-issue by handling many of my radio calls for me. I developed an early attitude of avoiding radio communication with ATC by actually altering routes to avoid airspace. I’ve since gotten over this problem and will talk to anyone on the radio.
- Flying in wind. If wind speeds got over 8 or 10 mph, he’d cancel our lesson. I don’t think it was because he was afraid of the wind — he had over 1,000 hours of flight time. I think it was because he was afraid of letting me try to fly in the wind. Maybe he was worried I’d have a lot of problems. It didn’t matter. He made me afraid of the wind, which is ridiculous when you consider I’m flying a helicopter and can take off or land into the wind anywhere.
As a result of my initial training, I always faced windy flying days with caution. Maybe too much caution.
I remember flying my R22 from Wickenburg, AZ to Placerville, CA years ago. I was supposed to do it in one day. I got an early enough start. But I hit windy conditions at the Tehatchapi Mountain pass where I’d planned to cross from the high desert near Edwards Air Force Base to California’s Central Valley. Anyone who knows the area shouldn’t be surprised. It’s lined with dozens, if not hundreds, of windmills for a reason. But I was afraid to brave the pass and wound up spending the night at Rosamond, CA. I don’t recommend doing that and I certainly won’t do it again.
Could I have made the trip safely? Nowadays, I think I could. But then, I wasn’t sure.
I built all my flying time in my own aircraft on personal and commercial flights. When I got to 1,000 hours, I applied for a job at the Grand Canyon. I had a friend who recommended me to one of the tour operators there. I had a good interview and got the offer. Flying at the canyon had always been a dream of mine, so I happily took the job.
One thing about Arizona in the spring is that it’s windy. One thing about northern Arizona in the spring is that it’s very windy. I soon learned not only how windy it could get at the Grand Canyon, but how much wind we were expected to fly in.
Our company had two methods for determining whether it was too windy to fly:
- We’d fly until one of the pilots came back and said it was too windy. Now most of the pilots were guys and most of them were in the 24 to 30 year old range. They spent their pilot lounge waiting time watching car races and extreme skateboarding shows on the television there. There was a definite testosterone thing going on. Obviously, if you came back from a flight and said it was too windy to fly, you were a sissy. So none of the young guys did it. There were also two women on staff, including me. Neither of us would call it because then we’d be confirming that we were sissies, which the guys already suspected. (Frankly, my personal gauge of what was too much wind was way off and I couldn’t trust my judgement anyway. I figured if it wasn’t too windy for everyone else, it couldn’t be too windy for me.) Fortunately, there was an older pilot named Ron who didn’t care about macho bullshit. When Ron went out on a flight and got tossed around too much in the sky — usually by the Dragon’s Tail or Dragon’s Head (two calling points on the Dragon Corridor) — he’d come back in a huff, go straight to the lead pilot, and shut us down for weather. The rest of us would breathe a silent sigh of relief.
- When the wind in the company’s tower at the Grand Canyon Airport hit 50 miles per hour, we’d shut down. And yes, if Ron wasn’t around, we’d sometimes fly right up until that point.
So, as you can imagine, I quickly learned how to fly in high winds.
The only time I got into any real trouble was one day when I was landing on a pad in front of our terminal at the Grand Canyon. There was a good, stiff crosswind coming from my left as I hover-taxied into position. I was flying a Bell 206L1 C30P Long Ranger. Anyone with any experience in Bell products should be able to imagine what a 1000-hour pilot brought up in Robinson equipment might experience in such a situation: LTE (loss of tail rotor effectiveness). I started rotating to the right. I added left pedal and nothing happened. I added more left pedal and got a tiny bit of response. I was now almost 30° off center and my tail would soon be approaching the fuel pit. I slammed the left pedal to the floor, spun the nose of the helicopter around to face the front of the pad, and brought the collective down swiftly, for a rough yet straight landing. It was my first LTE experience and it scared the hell out of me. Robinson puts a hell of a lot more authority in its tail rotors than Bell does.
As another flight instructor once told me, “The wind is your friend.” He was right — but I couldn’t understand why until I’d flown in windy conditions. That taught me how the wind could help me take off and land with a heavy load or get to my destination faster. And how it forced me to dance on the pedals for a crosswind landing, or milk the collective to avoid the [over-]sensitive low rotor RPM horn on takeoff or landing.
The Risks of Wind
LTE is only one risk of flying in windy conditions. As I fly tomorrow, any time I’m in a crosswind situation, I need to worry about the aircraft trying to weathervane into the wind. If the wind is from the left, LTE becomes an possible issue — although I’ve never had an LTE problem in a Robinson. We’ll be flying light with just two on board, so I should have enough power to handle the situation. The trick will be to either avoid it (which I prefer) or recognize the onset and avoid it before it causes a problem.
Another risk of high wind to semi-rigid rotor systems (which is what most two-bladed systems are) is excessive flapping. This was our main concern flying Long Rangers at the Grand Canyon in high wind. (And you thought it was pilot air sickness.) When Ron came back and shut down flying for the day, he’d come into the pilot room and tell us all how crazy we were for flying. It was dangerous, he’d say. But what did we know? We were 1000-hour pilots, many of whom had no real life flying experience. How many of the former flight instructors around me did what my first CFI did and keep their students — and themselves — out of the wind?
My main concerns tomorrow will be keeping the aircraft under perfect control as I fly a search pattern. There will be a lot of turning back and forth and maybe even a little hovering. I’ll have to keep track of where the wind’s coming from and what low-level obstacles — think hills and ridges — it has to cross to get to me. Each little bump in the ground means a bump in the air on a windy day.
How much wind is too much?
I know a lot of pilots who won’t fly in what I now consider moderate winds (10 to 25 mph). This past February, I was in Parker, AZ, doing a video flight for an off-road race. There were a bunch of helicopters working for various race teams or video production crews. Before dawn, as the cars were lining up at the starting line, they took off, one by one. The winds were 13 gusting to 18. I was prepping my passengers for the flight when the pilot of a Jet Ranger came over and asked if I was going to fly. I told him I was and I think he was surprised. He told me it was too windy for him.
Anyone with significant flight time who reads this should be able to give me an idea of their own personal maximums for wind. I’d love to get your feedback here. Use the comments link or form. And if I’ve said anything absolutely stupid in this post, please correct me gently.
At this point, I’m thinking that 30 mph with a gust spread of no more than 10 mph should be okay for this mission. If I find out I’m wrong, I’ll be sure to let you know.
In the meantime, I’m hoping my client calls to start the mission an hour or two earlier. I think if we can finish up before noon, we’ll avoid the worst of the wind.