Tag Archives: safety

Why Helicopters Don’t Normally Take Off Vertically

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Just because you can do something, doesn’t mean you should do it.

Every once in a while someone watching one of my YouTube videos or searching for answers on the web that bring them to this blog ask why helicopters don’t take off straight up. I guess these folks know that it’s possible and they’ve seen it often enough in the movies to think that it’s normal or at least okay. It’s neither.

I actually explain why in my much longer post about the Deadman’s Curve. But I’ll try to keep it simpler here.

The Basics

Let me start off by saying that helicopters can glide. Yes, if the engine fails, the pilot still has control over the helicopter and can fly it, using autorotation, to the ground. If conditions are right and the landing zone is appropriate and the pilot’s skills are sufficient, the pilot and passengers should be able to walk away and the helicopter might even be able to fly again.

Notice that I mentioned three ifs:

  • if the conditions are right
  • if the landing zone is appropriate
  • if the pilot’s skills are sufficient

Height-Velocity Diagram for R44 HelicopterIt’s that first if that the pilot usually has complete control over: the conditions of flight. That’s where the Height-Velocity Diagram comes into play. This diagram, which is part of the Pilot Operating Handbook (POH) that pilots are required to know inside and out (and even carry on board, as if we could consult it while flying), shows the flight profiles in which an autorotation is most likely to be completed successfully. By “flight profiles,” I’m referring to a combination of airspeed and altitude.

To meet the requirements of that first if — in other words, to fly the safest flight profile in the unlikely event of an engine failure — the pilot needs to stay out of the shaded area of the Height-Velocity Diagram. A recommended takeoff profile is shown on this chart by a dashed line that starts at 0 knots and less than 10 feet off the ground, accelerates through 45 knots while climbing less than 15 feet, and then climbs out at a speed greater than 50 knots.

Make a mental picture of that. If you’re not going to climb above 10 feet until you get to at least 30 or 40 knots, are you going to be flying straight up? No. You’re going to be taking off a lot like an airplane might, with a bunch of forward movement before you start climbing.

This is why a “normal takeoff” for a helicopter climbs out after gaining airspeed — instead of climbing straight up. It’s for safety reasons.

(This is only part of the reason why we don’t land straight down, but I’ll save that for another blog post if I get requests for it.)

FAA Guidance

The FAA has a wealth of free information about flying, including “handbooks” that explain exactly how to fly. I’ve linked to the Helicopter Flying Handbook many times; if you don’t have a copy of this excellent guide and are interested in flying helicopters, download it in PDF format here.

Here’s what it says about performing a normal takeoff from a hover (position 1 in the image that follows) on Page 9-12:

Start the helicopter moving by smoothly and slowly easing the cyclic forward (position 2). As the helicopter starts to move forward, increase the collective, as necessary, to prevent the helicopter from sinking and adjust the throttle to maintain rpm. The increase in power requires an increase in the proper antitorque pedal to maintain heading. Maintain a straight takeoff path throughout the takeoff.

While accelerating through effective translational lift (position 3), the helicopter begins to climb, and the nose tends to rise due to increased lift. At this point, adjust the collective to obtain normal climb power and apply enough forward cyclic to overcome the tendency of the nose to rise. At position 4, hold an attitude that allows a smooth acceleration toward climbing airspeed and a commensurate gain in altitude so that the takeoff profile does not take the helicopter through any of the cross-hatched or shaded areas of the height/velocity diagram. As airspeed increases (position 5), place the aircraft in trim and allow a crab to take place to maintain ground track and a more favorable climb configuration. As the helicopter continues to climb and accelerate to best rate-of-climb, apply aft cyclic pressure to raise the nose smoothly to the normal climb attitude.

Normal Takeoff
This is an exaggerated view. In reality, each position would be a lot farther apart horizontally.

In the above text, in an R44, effective translational lift (ETL) occurs between 15 and 25 knots, normal climb power is about 45 knots, and then climb out power (best rate of climb) is 60 knots. So you basically stay within 10 feet of the ground until you’re at 45 knots, then accelerate while climbing to 60 knots, and then climb out at 60. These numbers may be different for other aircraft but are likely similar.

Real Life Situations

Watch My Helicopter Videos on YouTube

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Of course, one of the benefits of helicopters in many operational situations is that it can fly straight up. For example, I can take off from a confined space — perhaps a forest clearing — by being able to climb up above obstacles (the trees around me) before picking up airspeed and flying away. Is this safe? Well, there isn’t any signifiant danger unless the engine quits. And although the chances of the engine quitting are very slim, it is possible.

Years ago, while doing a rides event at the local airport with some fellow pilots who were working with me for cherry season, I noticed that one of the pilots was departing our landing zone by climbing straight up for 20 or 30 or even 50 feet before gaining airspeed. He was putting the aircraft right in the shaded area of the Height-Velocity Diagram. In other words, he was adding risk to his flight by basically ignoring the recommended takeoff profile.

With passengers on board. At a crowded event.

I’ve got a pretty good imagination and was immediately able to “see” what could happen if his engine quit. The helicopter would drop down with its blades still spinning. Everyone on board would likely be killed or seriously injured. And when all those spinning parts hit the ground and started flinging off in every direction, they’d likely kill or injure dozens of onlookers.

What were the chances of his engine quitting? About as close to zero as you can get without being zero. But that isn’t zero. It could happen.

After seeing him do this at least four times and realizing he wasn’t going to stop, I got on the radio and told him to stop. He asked me why. Knowing that I was talking on a frequency that could be heard by his passengers, my passengers, any other aircraft flying around the area, and anyone monitoring on the ground, I kept it simple: “Just because you can do something doesn’t mean you should.” I let him think a bit about why he shouldn’t and he stopped. (If he didn’t, I would have kicked him out of the event.)

Over the following month or so, I got to know this pilot better and I didn’t like what I saw. I don’t need to go into details here, but I feel that he’s the kind of pilot who will likely get himself killed doing something dumb in a helicopter. I’m just glad I took steps to make sure it didn’t happen on my watch.

Question Answered?

If this doesn’t answer the question about why helicopters don’t take off vertically, I don’t know what could. Please don’t hesitate to share your questions, comments, and stories in the comments for this post. Thanks!

Leaving a Parked Helicopter with the Engine Running

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An explanation of something I said in one of my recent YouTube videos.

I recently published a video on the FlyingMAir YouTube channel where I flew from my cherry season landing zone to my house. I was going to do a much longer flight that day with a friend and, when I reached the helicopter, I realized I’d forgotten my iPad, which I use with Foreflight for situational awareness and detailed airport information in flight. Faced with a choice of taking 20 to 30 minutes to drive back home and get it or just making the one minute flight up to my house on my way to pick up my friend, I went with the quicker option.

In the video, as I’m coming in for landing, I lament that a helicopter isn’t like a car and I can’t just keep it running while I go inside the house. I never explained why. A helicopter pilot — and even an airplane pilot — should know, but I forget sometimes that my video audience isn’t always directly involved in aviation. I got several questions — and a good story — in the video comments about leaving an unattended helicopter with the engine running. I thought I’d take a moment to share and expand on what was said in those comments.

First, Understand How a Helicopter Flies

The main danger of leaving a helicopter running while unattended is the possibility of it become airborne enough to move and crash. Never fear — if it does get airborne at all, it’s not going to fly away by itself. It will crash and likely pretty damn quickly. More on that in a moment.

Dynamic Rollover
The usual outcome of a helicopter trying to take off by itself is something like dynamic rollover, which is shown here. The helicopter gets hooked on something on the ground and rolls over. (This photo by John Murphy is from Wikipedia and used under the Creative Commons Attribution-Share Alike 2.0 Generic license. (Thanks, John, for sharing photos to help bloggers illustrate things like this.))

For a helicopter to get light on its skids and airborne, it needs a two main things:

  • Rotor RPM. The main rotor(s) must be spinning. Theoretically, a Robinson can fly at 80% RPM plus 1% RPM per thousand feet of density altitude. So at my house on a warm summer day, I’d estimate 83% RPM would be enough to fly, although we always fly at 100% RPM (unless there’s some sort of in-flight problem that makes this impossible, in which case, we’d land as soon as possible). For this reason, it’s never a good idea to leave the rotors spinning at anywhere near 100% RPM unless the pilot is at the controls, paying attention and ready to fly.
  • Collective Pitch. The collective control in the pilot’s left hand changes the pitch on the rotor blades the same amount (collectively) when it’s pulled up. With the collective full down, the blades are “flat” (or close enough for argument’s sake) and should not be able to get the angle of attack they need to produce lift. (And yes, the collective does look quite a bit like a compact car’s parking break lever.)

It’s the pilot’s responsibility to throttle down to an appropriately low RPM when on the ground. A Robinson’s cool-down RPM is between 60% and 70%; far too low for the helicopter to fly. When I flew at Papillon years ago, we’d just throttle down to the stop, which I think left us at around 70% RPM (but don’t quote me on that; it’s been 16 years). There are a few reasons why a pilot might not do this, but we don’t need to split hairs here because all of those reasons involve a pilot staying in the cockpit.

All the helicopters I know provide safety controls to prevent the collective from creeping up by itself. This is usually in the form of a collective friction lever (or possibly knob?) that the pilot should secure as part of her shutdown process. It becomes automatic. You set down, you throttle down to a cool-down or idle RPM (depending on your needs), and set the friction. Half the time, I don’t even remember doing it, but when I look down, it’s set.

So Is It Safe to Leave the Engine Running without a Pilot on Board?

Doing both of these things — reducing RPM and securing the collective in a full down position — should prevent a helicopter from misbehaving when parked when the engine is running. And lots of pilots will actually walk away from a helicopter with the engine running. Let me elaborate.

Suppose I was sitting in the helicopter with the engine running and I realized I needed something out of the back seat storage area. I need to get out to fetch it. Would I shut down?

The answer is no. I’d start by confirming low RPM and secured collective. Then I’d take off my headset and seat belt, open my door, climb out, open the back door, fetch what I needed, close the back door, and get back into my seat. During that entire time, I’d be well within reach of the controls if I started to hear or feel something weird going on.

Likewise, when I worked at Papillon, they’d routinely land a Bell 206L in the Native American village of Supai at the bottom of the Grand Canyon. The pilot would throttle down and secure the collective, then get out, walk around the front (never back!) of the helicopter, open the luggage compartment, and pull out luggage for the departing passengers. (That was back in 2004; I have no idea if they still do this but assume they do. It makes sense given the possibility of restarting difficulties without a ground support crew/equipment.)

Meanwhile, up at the Grand Canyon South Rim base, if a pilot needed to use the bathroom between flights, he’d have to wait until another pilot came down and sat in his seat until he returned. No passengers would be loaded during this time. This was a smart safety measure that some folks might consider overkill. I don’t.

A friend of mine who owned an R44 started up his helicopter on the ramp of his home base airport, which, at the time, I believe was Salinas in California. As he was warming up the engine, he realized he was missing a chart. Rather than shutting down, he simply left the helicopter empty, idling on the ramp, while he went to the on-airport pilot shop and bought the needed chart. He got into a ton of trouble with airport management when an airplane pilot complained about it. Friend or not, I think he exercised poor judgement when he did that.

The Story in Comments

One of my YouTube channel’s commenters, George Reynolds, had this to say about my video:

Not like a car, leaving the engine running. Reminds me or a true accident report where the pilot landed beside a house to impress a friend and got out, leaving the 3 forestry workers in the helicopter with the engine running. One of them thought the “handbrake” ought to be applied and the consequences was a wreck, but fortunately no injuries….

My first thought was OMG, what a story! It’s a perfect example of what can happen when a pilot fails to properly brief his passengers.

Going back to my original situation, if I had a responsible adult passenger in the front seat when I landed at my house, I’d throttle down, secure the collective, and advise the passenger to leave the controls alone, especially the collective, which should not be raised under any situation. Then I’d feel comfortable enough leaving the engine running.

What Could Happen

George’s story sent me to the NTSB database to look for the accident in question. I searched using all kinds of key words based on his story: handbrake, brake, house, passengers, pulled collective. I did not find a single story that matched.

But I did find others. Here are a few summaries; emphasis added:

Accident report LAX97FA149 on April 7, 1997 in Los Angeles, CA tells this story:

The pilot exited the helicopter to escort a deplaning passenger. The student pilot rated passenger was left sitting in the helicopter with instructions not to touch the controls. While the pilot was standing nearby, the helicopter began bouncing up and down in a resonant mode. The pilot ran back to the helicopter and pulled the fuel flow control lever into the cut-off position. The helicopter yawed to the right and settled back on the deck. Investigation revealed the full down position of the collective was spring loaded to keep tension against the control lock. An inspection of the helicopter revealed that the collective was not down and locked, nor were the frictions tightly applied. The manufacturer reported instances in which the collective lock was not seated properly, and consequently, the collective became released while the engine was running. If the lock slips off collective, the spring’s tension could force the control to move upward. No malfunction or failure was found with the engine or rotor systems.

So either the pilot hadn’t locked the collective or the collective lock had released due to a known design flaw.

Accident report LAX07CA034 on November 11, 2006 in Boulder City, NV says:

The helicopter rolled over after the pilot exited with the engine running and rotors turning to disconnect and move the auxiliary power unit (APU) to a secure location. The pilot left the helicopter running at 100 percent because he was charging the battery. The pilot’s back was to the helicopter when he heard the engine sound change. He turned around, and saw the front skids lift off the ground. The helicopter started to move in a backwards direction, and rolled over and went down an embankment.

Sorry, folks, but this is a stupid pilot trick, plain and simple. Never leave the helicopter at 100% RPM when there’s no pilot at the controls.

Accident report LAX01FA252 on July 21, 2001 in Los Angeles, CA reports:

The pilot got out of the helicopter with the engines running and the rotors turning to check on the security of a cabin door, and the unmanned helicopter began moving on the helipad and rolled over. The pilot had completed a nightime, helicopter, air taxi flight, and was preparing to depart the elevated helipad to reposition the helicopter to the operator’s base. After deplaning his passengers the pilot returned to the cockpit and was preparing to depart when he noticed a door unsecured indication on the instrument panel for the left cabin door. The passengers had deplaned through the right-hand door and the left door annunciation had not been on during the inbound flight. He thought one of the passengers might have released the left door latch inadvertently while preparing to deplane. He idled the engines and exited the cockpit to check the door. He reclosed the door and returned to the cockpit; however, the door open annunciation came on again. He recalled leaving the cockpit “2 or 3 times” to deal with the door and said he was “frustrated with it.” He did not recall retarding the engine power control levers to ground idle before leaving the cockpit the final time. While out of the cockpit, the wheel-equipped helicopter started to move as the pilot was returning to the cockpit. He recalled it was moving toward the edge of the helipad. He returned to the cockpit; however, before he could regain control there was a confusing sequence of events and the next thing he knew the helicopter was on its side. The pilot reported there were no mechanical discrepancies with the helicopter up to the time of the event. He remarked that it was very light [weight] with no one else on board. On the deck of the helipad there was a tire skid pattern consistent with a dynamic rollover event. The engine power control levers were found in the “fly” position.

I really feel for this guy. Something is acting up, giving him grief, and he’s frustrated. Unfortunately, that can also make you sloppy. I don’t know much about Sikorsky S-76 helicopters and nothing about the “fly” position, but I have to think that a helicopter should be set to “fly” when the pilot intends to fly. Maybe someone reading this can fill in more details? Since the chances of me ever flying an S-76 are very slim, I’m not interested in researching it.

Why This Matters

I’m a student in the School of Thought that says the more you know about what could happen, the better equipped you are to make smarter safety-related decisions.

In my video, my landing zone was good, there was little or no wind, the collective friction on my helicopter works fine, and I could have throttled all the day down to 60% RPM if I wanted to. The chances of the helicopter moving an inch while I was in my house were nearly zero.

Nearly.

There’s always a chance that something unexpected will happen. Having lost one helicopter already, I’m not interested in losing another. So I do what I think is safe, even if other folks think it’s overly cautious.

If the folks in the four accident stories I shared here had been students in the same School of Thought I’m in, their stories wouldn’t need to be shared.

Drone Pilots: Beware of Bird Strikes!

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Just a quick warning, with photos.

Last week, I did a few photo missions with my Mavic Pro flying camera. For two of the msisions, I launched from an open area at the far east side of the Tyson Wells complex in Quartzsite, just south of Keuhn Road.

I’m in the habit of using the Return-to-Home feature of my Mavic to get it back to its launch point quickly and efficiently. In all honesty, I’m awed by its ability to land exactly on its takeoff spot nearly every single time. I like to watch, with my finger poised over the pause button on the control (just in case), as it comes to the right coordinates far overhead, turns to the direction in which it took off, and descends to the spot.

On one of the three missions I flew from that spot, a small flock of pigeons flew right past the Mavic. I watched in shock and a bit of horror as the five or six birds swooped around my fragile aircraft. I felt relief as the Mavic continued its descent unharmed, but the whole thing repeated itself when another flock — or the same flock? — swooped past. Again, the Mavic was unharmed.

I happened to have the video camera going when this was happening. Here are two screen grabs, one from each flight, that show the closest encounter. The first one was definitely closer.

Near Miss
This reminds me of a scene from The Birds.

Near Miss
The bird is a bit farther off in this one. Can you see it?

Of course, the camera can’t capture action in a direction it isn’t pointing. For all I know they could have come closer behind the camera.

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While this is all kind of cool in a weird sort of way, it wouldn’t have been so cool if one of those birds clipped a rotor. The Mavic has four independently powered rotors. If any one of them was destroyed, I’d have to think the whole thing would immediately go out of balance and crash. This is one good reason why we don’t fly drones over crowds of people. Even though the Mavic weighs in at less than 2 pounds, having one crash onto your head from 150 feet would definitely cause some injuries.

Honestly, I’m surprised this hasn’t happened yet. A matter of time?

More on “Scud Running”

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Clarifying my position on flying in low visibility conditions.

Note: A version of this post originally appeared in AOPA’s Hover Power blog. If you’re a helicopter pilot, you owe it to yourself to check in there regularly to read great articles written by experienced helicopter pilots.

In my post about long cross-country flights for AOPA’s Hover Power blog (which I republished here), I brought up the topic of scud running. Apparently, my account of a flight into low visibility conditions, which I referred to as “scud running,” set off a lot of alarms with readers. One reader seemed to think that I “endorsed” scud running. (I don’t.) Another reader found it necessary to share Accuweather definitions and a video that described “scud clouds.” (I don’t recommend Accuweather as a source of weather information per FAR Part 135.213(a).) Someone called for a “definitive statement from you declaring NO to EVER scud running.”

It’s that last comment that got me thinking about what some readers think about the reality of flying. Fortunately, two other readers who are obviously experienced pilots came forward and offered comments that clarified my position on flying in limited visibility situations. I’d like to elaborate on those comments, provide an example situation for consideration, and review the FARs regarding helicopters and weather minimums.

My Definition of “Scud Running”

Let’s start with exactly what I’m talking about when I use the phrase “scud running.” Reader Dan Schiffer nailed it when he responded to one of the commenters. He said, in part:

It’s a term most pilots use to discuss low visibility conditions that we all are faced with occasionally due to changing weather.

To me, scud running is any situation where low ceilings or low visibility require you to alter your route around weather. And yes, low ceilings are a part of low visibility — after all, if you’re in mountainous terrain, don’t low ceilings obscure your visibility of mountainsides and peaks?

The FAA discusses scud running in its Pilot’s Handbook of Aeronautical Knowledge:

This occurs when a pilot tries to maintain visual contact with the terrain at low altitudes while instrument conditions exist.

I discuss this in more detail later, when I cover weather minimums for helicopter pilots.

Neither my definition nor the FAA’s have anything to do with a so-called “scud clouds.” I can’t find any mention of these clouds in either the Aeronautical Information Manual (AIM) or Pilot’s Handbook of Aeronautical Knowledge. I did find a definition in AC 00-6A, Aviation Weather:

scud – Small detached masses of stratusfractus clouds below a layer of higher clouds, usually nimbostratus.

A Google search brought up a similar, but more detailed Wikipedia definition:

a type of fractus cloud, are low, detached, irregular clouds found beneath nimbostratus or cumulonimbus clouds. These clouds are often ragged or wispy in appearance. When caught in the outflow (downdraft) beneath a thunderstorm, scud clouds will often move faster than the storm clouds themselves. When in an inflow (updraft) area, scud clouds tend to rise and may exhibit lateral movement ranging from very little to substantial.

For the record, I’m definitely not endorsing flying anywhere near a thunderstorm or cumulonimbus cloud. The FAA says to maintain 20 miles separation from thunderstorms and that’s a pretty good rule of thumb.

So, in summary, when a pilot uses the phrase “scud running,” it usually means flying in low visibility conditions and has nothing to do with so-called scud clouds.

A Real-Life Example

I can only assume that readers who expect me to definitively state that a pilot should never ever engage in scud running as defined above either:

  • Haven’t had much time flying.
  • Haven’t gone on many long cross-country trips.
  • Fly in a place where visibility is never an issue.

Flying in low visibility is not something I want to do, but sometimes it’s something I have to do.

A Note about flying in remote areas

I’ve done just about all of my flying in the west: Arizona (where I learned to fly), Nevada, Utah, Colorado, New Mexico, California, Idaho, Oregon, and Washington (where I now live). In the 3,300 hours I’ve logged, I’d say that at least half of them were in relatively remote areas. Because of this, it’s difficult for me to remember that most pilots fly in more populated areas, where they’re seldom out of sight of a town or building.

As difficult as this might be for some people to believe, there are still many places in the U.S. where a helicopter pilot can fly for over an hour and not see a single sign of human life. I’ve flown 90 minutes in a straight line somewhere between Elko, NV and Burns, OR without seeing a building or a vehicle on one of the few dirt roads — just herds of wild horses running at the sound of my approach. I’ve flown over the high desert of the Arizona Strip, crossing just one dirt road over an 85-mile stretch of forest and canyons. I’ve flown the length of Lake Powell from the Glen Canyon Dam to Canyonlands National Park in the winter, passing just three seasonally closed marinas along the lake’s blue water and canyon mouths. I fly with a SPOT personal tracking device for a reason; if I go down out there — even by choice in a precautionary landing — no one would find me without some help.

So while “scud running” might seem like an unreasonable risk when you’re in an area with towns and airports every five or ten miles, it could be a matter of life and death when you’re out in the middle of nowhere and need to get somewhere safe. It’s not a black and white situation with a right or wrong answer.

Let’s look at an example. Suppose you’ve done all your flight planning and believe you can make a 2-hour flight to Point A, which is a rather remote place, without any weather/visibility concerns. You start the flight and things are fine for the first ninety minutes or so. Then the weather starts deteriorating. Maybe the ceiling drops or there are scattered rain showers that lower horizontal visibility in various places along your path. You can see well enough in your general forward direction and easily find paths around those showers that will get you closer to your destination, but things might be worse up ahead. Who knows? Even a call to Flight Service — if you can reach them on the radio in mountainous terrain with low ceilings preventing you from climbing — might not be able to provide adequate weather information if the area is remote enough.

Here’s where experience, judgement, and personal minimums come in. As helicopter pilots, we have three options:

  • Alter your route to completely avoid the weather, possibly ending up at a different destination. This might be the best option if there is an alternative destination and you have enough fuel to get there. But if your intended destination is in a remote place and you’re only 30 minutes out, there might not be an alternative.
  • Land and wait out the weather. Heck, we’re helicopter pilots and can land nearly anywhere. There’s nothing wrong with landing to wait out a storm. Remember, in an emergency situation, you can land if necesary, even in an area where landing is normally prohibited, such as a National Park, National Forest, Wilderness Area. (Again, I’m not recommending that you land in any of these places in non-emergency situations.) Do you have gear on board for an extended or perhaps overnight stay? This is another good reason to bring food on a cross-country flight.
  • Continue toward your intended destination. At the risk of sounding like I’m a proponent of “get-there-itis,” the destination is a known that’s a lot more attractive than the unknowns offered by the first two options.

There are many variables that will determine which option you pick. Here are a few of them:

  • Experience. If you’ve encountered situations like this before, you have a better idea of your comfort level than if you haven’t. You’ve likely also established personal minimums, possibly fine-tuned by real scares. The more experience, the better you’ll be able to deal with the situation and make the right decision.
  • Alternatives. If there is an alternative destination within range that you can safely reach with available fuel plus reserves, why wouldn’t you go for it?
  • Available fuel. There’s a saying in aviation: “The only time you have too much fuel is when you’re on fire.” One of the challenges of planning a long cross-country flight is making sure you have enough fuel on board to deal with unplanned route changes. But when flying to extremely remote areas, you might need almost all the fuel you have on board to get there. That definitely limits your options.
  • Actual weather conditions. If you can see a path ahead of you with potential landing zones and escape routes along the way, you’re far more likely to succeed at moving toward the destination than if the weather is closing in all around you. Never continue flight to the point where you don’t have at least the option to land and wait it out. The trick is to turn back or land before that happens; experience will be your guide. Likewise, if what you’re seeing tells you that the weather is localized and better conditions are just up ahead — perhaps you see sunlight on the ground beyond those heavy showers? — continuing flight might be the best option.

So what’s the answer? There isn’t one. As the pilot in command, you are the decision maker. You need to evaluate and re-evaluate the situation as it develops. You need to make a decision based on your knowledge and experience. If in doubt, choose the safest option.

Clouds
With mist, rain, and low clouds, would you keep flying?

Weather Minimums

Despite the severe clear weather I usually see around my home in Central Washington State, weather minimums are on my mind lately. Why? Mostly because my Part 135 check ride is coming up and I’m always a bit hazy on them. Spending most of my flying career in Arizona didn’t do me any favors when it comes to knowing when it’s legal to fly — or being able to identify different types of fog by name, for that matter.

So let’s look at weather minimums as they apply to helicopters.

FAR 91.155, Basic VFR weather minimums sets forth weather minimums for each type of airspace. I’m going to concentrate on Class G airspace, mostly because that’s the type of airspace I’ve been talking about.

According to the FARs, a helicopter may legally operate under VFR in Class G airspace during the day with a minimum of 1/2 mile visibility clear of clouds. Conditions less than that are technically IMC, thus invoking the FAA’s definition of “scud running” discussed above.

But what if visibility in your desired flight path is 1/4 mile or less but visibility 30° to the right is a mile or more? That is possible with localized showers or very low scattered clouds. Are you allowed to fly? I think that if you asked five different FAA Inspectors, you’d get a bunch of different answers. But if you crashed while flying in those conditions, the NTSB report would claim you were flying VFR in IMC.

What’s the answer? Beats me.

Scud Happens

What I do know is this: If all your preflight planning indicates that weather and visibility will not be an issue during a flight but unexpected weather conditions come up, you need to react to them. As helicopter pilots, we’re lucky in that we have options to avoid flying into clouds and the terrain they obscure. At the same time, we don’t want to push that luck and get into a situation we can’t get out of safely. Experience, skill, and wisdom should guide us.

Scud running is never a good idea, but sometimes it’s the best idea under unforeseen circumstances. It’s your job as a pilot to (1) avoid getting into a dangerous situation and (2) make the best decision and take the best actions to complete a flight safely.

Doors-Off Flying

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Things to keep in mind.

Note: A version of this post originally appeared in AOPA’s Hover Power blog. If you’re a helicopter pilot, you owe it to yourself to check in there regularly to read great articles written by experienced helicopter pilots.

Summer is on its way and, in most parts of the northern hemisphere, that means warm weather will soon be upon us. Not every pilot is fortunate enough to fly a helicopter with air conditioning. When I lived and flew in Arizona, it was common for me to take all of the doors off my R44 in May and leave them off until September. It was that hot every single day. (And no, I don’t miss it one bit.)

Of course, pilots don’t need warm weather as a reason to take the doors off. Sometimes the mission you’re flying requires it. Aerial photography is a great example — there aren’t too many photographers who would be willing to pay hundreds of dollars an hour to fly with you and be forced to shoot photos through highly reflective, possibly scratched Plexiglas.

Door Off
For this memorable video flight, the videographer sat behind me with his door off.

When you remove the doors from a helicopter, you add an element of risk to the flight. Fortunately, the risk can be controlled if you fully understand it and do what’s necessary to reduce or eliminate it. That’s what I want to touch upon in this post.

Loose objects

The most obvious risk is from loose objects blowing around the cockpit or, worse yet, exiting the aircraft. This is a real danger, especially if an object hits the tail rotor or someone/something on the ground.

Want some examples of how dangerous this can be?

  • NTSB WPR14CA363
    “While in cruise flight an unsecured jacket departed the helicopter through an open window. The tail rotor drive shaft sheared as a result of the jacket’s contact with the tail rotors. The pilot subsequently initiated a forced landing to an orchard where during landing, the main rotors struck and separated the tailboom.”
  • NTSB WPR13CA071
    “Prior to the flight, the doors were removed in order to make it easier for the passengers to board and exit the helicopter…. After the two passengers were transported to a work site location, the right rear passenger exited the helicopter and placed the headset on the hook located behind the front seats. After departing the site, about 3 to 5 minutes later while en route at an elevation of about 1,000 feet above ground level, the pilot felt something strike the helicopter. After landing and upon inspecting the helicopter, the pilot discovered that the right rear headset was missing and that the leading edge of the tail rotor had been damaged.”
  • NTSB LAX03TA150
    “While in cruise flight, the back door on the helicopter opened, and a flight jacket that had been unsecured in the back seat departed the helicopter and became entangled in the tail rotor assembly. The tail rotor assembly subsequently separated from the tail boom, and the pilot was unable to maintain control of the helicopter.”
  • NTSB FTW86LA047
    “The pilot failed to assure the cabin door was properly closed before flight, or the cabin door just popped open during flight, allowing an unsecured life vest to blow out the door and into the tail rotor blades. This resulted in the entire tail rotor assembly departing the helicopter.”

(As some of these examples show, you don’t need to have the doors removed to have an unsecured item depart the helicopter and get into the tail rotor.)

Robinson Helicopter warns about this in Safety Notice SN-30, “Loose Objects Can be Fatal.” It recommends that pilots firmly latch all doors and even goes so far to recommend that pilot never fly with a left door removed. (Remember, the tail rotor is on the left side in a Robinson and many other helicopter models.)

I know that my engine starting check list includes an item to assure that loose items are secure. Yours should, too. While this is always important, it’s vital for doors-off flight.

Be sure you warn passengers of the danger of an item exiting the aircraft. Even something as small as a lens cap or lens hood can do significant damage to the tail rotor in flight.

Never Exceed Speed

You might not realize this, but your helicopter’s never exceed speed might be reduced with the doors off. On a Robinson R44, for example, Vne is reduced to 100 knots with the doors off, even if other conditions such as altitude and temperature would allow a faster speed.

My understanding from the Robinson Factory Safety Course is that this reduction of Vne is for structural reasons. (If someone knows better, please correct me in the comments.) There’s more buffeting wind inside the cabin with one or more doors off than with all doors on.

Check the Pilot Operating Handbook for the aircraft you fly the next time you remove doors to make sure you don’t operate beyond doors-off Vne.

Securing Passengers

This might seem like a no-brainer, but if you’re going to remove doors, your passengers had better be secured in their seats with either seat belts or harnesses.

Because some of my aerial photography or video clients like a greater range of movement in their seats than seat belts allow, I have a mountain climbing harness with a suitable strap for securing it to the aircraft frame. I make this available to clients as an option if they don’t have their own. Under no circumstances do I allow my passengers to fly without being secured, especially when their doors are off.

Keep in mind that while a photographer might use a harness to secure himself in the aircraft, you must make sure he knows how to release the harness from the aircraft in the event of an emergency — just as your preflight briefing must tell passengers how to release their seat belts.

Dangling Seat Belts

Of course, it was my generous offering of a harness to a photographer that resulted in more than $2,000 of damage to my aircraft when he used the harness but failed to secure the seat belt at his seat. The seat belt buckle dangled outside the aircraft for the duration of our 90-minute video flight chasing racing trucks over desert terrain. On landing, the passenger side fuel tank and area just outside the door frame had at least 50 dings and paint chips in it. How he didn’t hear it repeatedly striking the aircraft near his head is something I’ll never figure out.

Of course, it was my fault for not catching this prior to starting up and taking off. Expensive lesson learned.

Conclusion

While I don’t think there’s anything wrong with taking the doors off a helicopter prior to flight, it does give the pilot more responsibilities to assure that everything is secure and all passengers are properly briefed.

Or isn’t that something we’re already supposed to be doing?