Tag Archives: flight training

Helicopters 101: Weight

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Gross Weight ≠ Center of Gravity.

Articles in the Helicopters 101 series:
– Flight Planning
– CG
– Weight
– Hover Charts
– Ground School

I was recently pointed to a blog post by Tim McAdams, AOPA’s helicopter blogger. [A side note here: It’s nice to see that AOPA has finally realized that the first “A” in its name, which stands for aircraft (not airplane), does indeed include helicopters. I’ve been waiting more than 10 years for this. But I digress.] The post, titled simply “Gross weight,” is a brief discussion of helicopter gross weight and an accident caused by a pilot attempting to fly over max gross weight.

Commenters Miss the Point

Many of the comments following this post mentioned Center of Gravity (CG) or Weight and Balance (W&B). At least two commenters offered links to their Excel worksheets to perform weight and balance calculations for the aircraft they fly. (I also have my own Excel solution for my R44.)

It seemed to me, however, that they were missing the point. The article wasn’t about CG or W&B. It was about weight. You can do the calculations in your head for that:

+ Helicopter Empty Weight (including oil and unusable fuel)
+ Weight of Fuel On Board
+ Weight of pilot and Passengers
—————————————————
= Gross Weight

Take my helicopter, for example. Using the above formula for a flight with half tanks of fuel, me, and two people weighing 150 and 200 pounds on board, the formula would be something like this:

+ 1500
+ 150 (that’s 6 lbs x 25 gallons)
+ 500
————————–
= 2150

Because the max gross weight of my aircraft is 2500 pounds and this total is less, I’d be flying within max gross weight limitations. This does not mean I’m within CG — that’s a different calculation.

This is not higher math. A pilot should be able to make this calculation in a matter of seconds without a piece of paper — and certainly without a computer.

In my opinion, this should be the first calculation a pilot makes when planning a flight. If you’re over max gross weight, don’t even bother doing a W&B calculation. You’ll need to offload some of that weight — fuel, a passenger, cargo — before you can even consider whether it’s loaded within CG limitations.

Max Gross Weight

Although the blog post was titled simply “Gross Weight,” what McAdams was really talking about was max gross weight — the maximum allowable aircraft total weight on takeoff. The two stories he related in his post dealt with aircraft that were likely over max gross weight on takeoff. One flight was uneventful; the other ended in a crash.

There are two aspects to a helicopter’s max gross weight:

  • IGE Hover

    IGE Hover Chart for a Robinson R44 Raven II. According to this, a helicopter may be able to hover in ground effect at max gross weight at 6,000 feet when it’s 95°F out.

    There’s the max gross weight for the aircraft, which is something you should never — in a perfect world, anyway — exceed. The manufacturer has created this limitation for a variety reasons and the ability to lift off or hover may not be one of them. For example, it could be structural. Would you want to fly a helicopter over max gross weight if you knew that every time you did, you could be putting additional stress on the airframe/blades/etc. that could lead to a failure in a future flight? I wouldn’t.

  • There’s a practical max gross weight as it applies to high density altitude. Look at the performance charts. Can you maintain an IGE hover at max gross weight when the LZ is at 6,000 feet and it’s 95°F out? I do a lot of high density altitude flying in Arizona and I’ve experienced a wide range of weight and density altitude situations. I can assure you, max gross weight might be a limiting factor at sea level, but it’s an optimistic number at high DA.

I flew at the Grand Canyon one season and got to know the operation very well. Some helicopters simply weren’t as powerful as others — even within the same make and model. For example, on a hot day, if I were flying a certain ship, I wouldn’t take a load that put me within 200 lbs of max gross weight. To the company’s credit, they knew which ships were the “dogs” and tended to load them lighter. I distinctly remember being asked over the radio while waiting on the pad if I could take 4000 pounds in the ship I was flying that day — one of the dogs. It was over 90°F and the ship had been flying sluggishly since noon. When I said no, they shuffled the passengers around to lighten my load.

It’s Up to the Pilot

McAdams’ first story explains how one pilot refused to take a heavy load while another stepped right up and took over. He quotes a non-pilot bystander as saying “Now there goes a real pilot.”

This is the attitude that’ll shorten a pilot’s career — and possibly his life. The attitude that says, “I’m a better pilot because I can handle the heavy load that this wimpy pilot won’t try.” The attitude that ignores aircraft limitations and flying conditions just to prove you can do something that a wiser pilot won’t attempt.

You know about old pilots and bold pilots, right?

[Another side note: When I flew at the Canyon, late in the season, the last fight of the day for one of the routes had the pilot facing right into the low-lying sun at a critical point in the flight: just as we were attempting to climb up the side of a canyon wall in a relatively confined area to fly over the North Rim. My eyes are extremely light sensitive — which is why I just about always wear sunglasses outside — and I simply could not see in front of me when I flew this part of the route at this time of day. So I asked the lead pilot to not put me on that route for the last flight of the day. Although he was obviously pissed off, he complied –probably because there were at least eight other pilots on duty who simply didn’t care and would do the flight without question. My point: don’t fly beyond your comfort level.]

Real Weights

McAdams’ second story, about the crashed heavy helicopter, relates how the pilot estimated weights: 150 lbs per passenger. Ah, if only our passengers were that light!

The FAA’s estimate is closer to 190 per person average.

In a perfect world, we’d be able to weigh every single passenger, fully dressed and holding their carry-on things, moments before the flight. Those weights would be used in our calculation. This is exactly what they did where I worked at the Grand Canyon, so they never loaded a ship over max gross weight and always had perfectly accurate numbers for CG calculations.

Nowadays, most of my flights are booked by phone and I have to trust passengers to give me accurate weights when they book. But I don’t. I add 10 pounds to each person. If the caller is estimating the weight of another passenger, I add 20 pounds. It’s better to overestimate the weight than underestimate it.

Center of Gravity

One more thing: being out of CG and being over max gross weight are two separate things. While you can be in both conditions, you can also be in either condition. This means that you can be within max gross weight limitations but still be out of CG.

But I’ll save a discussion of that for another post.

“I Want to Fly”

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E-mail from a reader.

I get the occasional e-mail from readers who evidently think I can perform miracles for them — or perhaps take them by the hand and lead them to the life they dream about. Like this one, which I got today:

I’m 35 no wife or kids and no ties to anything or anyone and want to learn top fly I can get the money to go to a school I just want to change careers and I have learned to live on 35k a year no matter how much income I dont mind being away from home for 14-28 days as long as there is hot showers and the internet please get back to me as I would like to find out more directly from you as to what I should be doing I have looked around for schools and filled out my FAFSA for aid

To the person who wrote this — who I won’t embarrass by mentioning any names — what the hell do you expect me to do for you?

If you’re incapable of doing your own research to find a flight school in your area, you’re likely incapable of learning to fly or getting a job as a pilot, too. Stop whining and begging for help from strangers. You’re 35 years old! Get your fucking act together and make your future happen.

And for chrissake, if you’re going to contact people by e-mail, learn how to punctuate!

Sorry, folks, but this is the end of a long week for me, I have a splitting headache, and I’m spending the night at a Super 8 Motel inhabited by loud drug addicts. Whatever patience I usually have for e-mail crap like what’s quoted above is long gone.

Real Pilot Experience

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Not all flying hours are equal.

A fellow helicopter pilot and I often debate the merits of the current system of pilot experience building.

In the U.S., a pilot generally gets his (or her) private, commercial, and CFI ratings, often picking up an instrument rating along the way. He then spends the next 500 to 1000 hours as a flight instructor, teaching other people how to fly under the close supervision of a chief flight instructor. With the golden number of hours — 1,000, for most helicopter pilot jobs — logged, the pilot goes on to an entry level position in a company where he’s closely supervised by a chief pilot who calls all the shots. Through the logging of time in various aircraft, the pilot works his way up to better-paying, more challenging jobs.

Parked in an Orchard
My helicopter, parked beside a pond in an orchard, waiting for rain during cherry season.

My friend and I didn’t follow this typical career path. Instead, we learned to fly, bought our own helicopters, and started our own flying businesses, learning through more varied experiences in a much shorter time. We both worked closely with the FAA to get our Part 135 certificates and pass annual check rides and inspections. And we generally agree that the hours we’ve logged are “worth” more than those logged by a typical pilot on the typical career path.

Now I know that the mere idea that all logged hours are not the same will bother a bunch of readers who are pilots on that typical career path. So I’ve decided to provide a comparative list of experiences based on real-life pilots so you can objectively consider my argument.

I recently had the opportunity to fly with two relatively new helicopter pilots. And a year ago, I flew with another one. I spent more than 14 hours of flight time with all three of them. Here’s how their experience stacks up against mine.

ThemMe
All three of these guys had private, commercial, and certified flight instructor (CFI) endorsements. At least one also had an instrument rating and a CFII rating.I only went through Private and Commercial helicopter training. I never became a CFI and although I started work on an instrument rating back in the beginning of 2008, I haven’t finished it.
All three of these guys had right around 300 hours of flight time. The vast majority of that time was in Robinson R22 helicopters — although I think one of them might have had most of his training in Robinson R44s because of his size. (He wasn’t fat, but he was very tall and with height comes weight.) Virtually all of their flight time was built with a CFI in the seat beside them, flying within 50 miles of the airport where they learned to fly.I have about 2,100 hours of flight time these days, built in Robinson R22, Robinson R44, and Bell 206L helicopters, with a tiny bit of stick time in a Hughes 500 and a Bell 47. I’ve flown in nine states, including Arizona, New Mexico, California, Nevada, Utah, Colorado, Oregon, Washington, and Idaho. I’ve flown over deserts, mountains, lakes, forests, canyons, and coastlines.
All three of these guys built their flight time in basic and more advanced training. That’s 300 hours of hovering, flying traffic patterns, practicing autorotations, and performing other textbook maneuvers to textbook standards. They flew mostly during the day in good weather, at or near sea level. When (or if) these guys get jobs as CFIs, they’ll build their next 700 hours of flight time sitting in a seat beside a variety of student pilots, handing the controls only until the student can perform basic maneuvers without assistance. Then they’ll keep the student pilot out of trouble by being ready to get on the controls while daydreaming about their next flying job — the one that might actually pay them enough money that they can afford to pay their rent.I built my flight time with about 200 hours of basic and advanced training followed by an enormous amount of cross-country flying — including far more solo flight time than the average pilot — and flights for hire. The for-hire flights include short rides, sightseeing tours, photo flights, aerial survey flights, video flights, air-taxi flights, wildlife survey flights, cattle spotting, and cherry drying. I’ve flown in perfectly clear daytime weather, under (and over) low clouds, around thunderstorms, through rain showers, and into the complete darkness of a remote desert night. I’ve landed on and off airports, from sea level to over 10,000 feet density altitude.
These guys have always flown under the close supervision of a CFI or chief flight instructor, following the rules laid down by their flight schools. Decision-making was likely limited to go/no go decisions that were likely based on conservative guidelines; in other words, if there’s a real go/no go decision to make, don’t go.About 1/4 of my flight time was flown under the close supervision of a CFI, chief flight instructor, or chief pilot. The rest of it was flown under my own supervision. I made all the decisions that needed making, from how much fuel to load and where to seat the passengers to what route to take and where to stop for fuel to how to find my way around the unforecasted thunderstorm in my path. And go/no go, of course.
All three of these guys are qualified to teach student pilots how to fly helicopters.I’m not.

What bothers me most is that limited experienced pilots are the ones teaching people how to fly. Then, after logging hour after hour of doing the same thing in the same basic conditions, they’re more qualified for a job than someone else with “better” experience but fewer hours.

Is there something wrong with this situation?

I’m not complaining about not being able to teach. I don’t want to. I like life far too much to put it into the hands of someone who doesn’t know how to fly. I just question the wisdom of using our least experienced certificated pilots to teach non-pilots how to fly.

Spraying with a Helicopter
An experienced agriculture pilot sprays wax on Apple trees from a JetRanger in Washington state.

When I was an 800-hour pilot, it bothered me that a typical 1,000-hour pilot on the typical career path was considered more experienced than I was. I was willing to prove that I was an as good — if not better — pilot than he was, but no one wanted to give me the opportunity. Sure, he can do autorotations better than I could — after all, he’d been doing them every day for much of his 1,000 hours of flight time. But how was he on off-airport landings? Planning cross-country flights? Landing at unfamiliar airports? Flying around or under or through weather? Managing power with a full load of full-sized passengers at high density altitude? Simply feeling the aircraft as an extension of his body that gave him the ability to fly?

That’s water under the bridge now. I’ve built my time and now qualify for a wide range of jobs. And if I get my CFI — which I expect to this winter — I could probably be a pretty good flight instructor.

But for now, I’ll just continue on my own career path. It may not be typical, but it’s challenging. And every flight offers the possibility of a real learning experience.

Not Ready for Solo?

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This one is too absurd to pass up without comment.

I was going through the NTSB reports for helicopters today, looking for a specific accident in Arizona that hasn’t yet been listed on NTSB.gov. I did, however find this report that seems to indicate a training problem with a solo student pilot that has 64 hours of helicopter flight time:

According to the pilot, she departed Frederick Municipal Airport (FDK), Frederick, Maryland, about 0745, with an intended destination of Lancaster Airport (LNS), Lancaster, Pennsylvania. The pilot reported that she conducted the cruise portion of the flight at an altitude of 3,000 feet above mean sea level (msl), at an airspeed of approximately 110 knots. After she established communications with the LNS air traffic control tower, and was getting ready to begin her descent to the airport, the pilot noticed that the vertical speed indicator was indicating a descent of approximately 1,000 feet per minute, and that the airspeed was approximately 120 knots. The pilot “raised the collective” pitch control in an effort to reduce or stop the descent, but the helicopter did not respond as the pilot expected, and the descent continued. She determined that she would not be able to reach LNS, and selected a field suitable for a landing. The helicopter landed hard in a soybean field approximately 8 miles west-southwest of LNS. It remained upright, and the engine continued to run after touchdown, until the pilot shut it down using normal shutdown procedures.

The preliminary report goes on to say that when investigators tested the aircraft’s engine, they didn’t find anything wrong with it. It was up to date on all maintenance, the fuel samples were clear, and there was no evidence of a problem.

Is it me or is the problem as simple as what can be gleaned from the above-quoted paragraph? Let’s review:

  • The helicopter was descending at 1000 feet per minute, which is pretty quick, but not nearly as quick as an autorotation or a steep descent from altitude. (I commonly descend at at least 1500 feet per minute when coming off the Weaver Mountains (4500 feet) to Congress (3000 feet) toward Wickenburg (2400 feet).)
  • The helicopter’s airspeed was up to 120 knots from 110 knots. That’s fast, even for an R44. I normally cruise at 110 knots when alone; I have to push pretty hard to get it up to 120 knots without adding power or beginning a descent.
  • The pilot “raised the collective.” Helicopter Flying 101 says that when you pull pitch (raise collective) on a helicopter with a governor or a correlator (or both, as this helicopter has), you’re increasing power.

So the pilot is already zooming through the sky, but she adds power to stop the descent? Doesn’t she understand how the cyclic works? Pull it back to slow down. If you keep your power setting the same, you should also slow your descent rate.

Here’s what I think happened, based on the information provided in the preliminary report and a little research. The pilot was cruising at 3,000 feet. She was “getting ready to begin her descent” to an airport at an elevation of 403 — a required descent of 2600 feet. What she didn’t realize is that she had already begun the descent. Possibly with the airport in sight, she’d pushed the cyclic forward, perhaps to adjust the sight picture of the horizon before her. (This is something I recall doing more than once when I was a new pilot descending from altitude, so I can understand how she might do it, too.) The net result of a forward movement of the cyclic without a power change is to speed up and descend — which is exactly what happened. With a power setting of 18 to 20 inches of manifold pressure, she could easily get into this situation.

Rather than attempt to slow down by pulling the cyclic back, she elected to arrest descent by adding power. This would only make the problem worse if she didn’t add aft cyclic. It was probably a flare near the bottom — perhaps drilled into her by numerous practice autorotations — that slowed her down and enabled her to touch down without slamming any harder into the ground.

What should she have done? As soon as she realized she was going so fast and descending, she should have added aft cyclic. This should both slow her down and reduce her descent rate. It doesn’t matter how much power is available; if the rotors are not stalling, the helicopter will fly. Gentle aft cyclic should enable her to get a better idea of what the problem is — if there is indeed a problem.

But it’s hard to imagine a power problem if there’s no loss of RPM or yawing to the right — neither of which is mentioned as a symptom of the problem. And believe me, if a Robinson has low rotor RPM, you’ll know it — the damn horn starts blaring at 97% RPM; she would have had enough power to fly with RPM as low as 85% (or probably lower).

What do I take away from this? This solo student pilot was not prepared for her solo flight. She evidently did not understand how the controls work together to manage airspeed and climb or descent rates. (This may have something to do with her experience as an airplane pilot.) When she noticed the descent rate and high speed, she possibly panicked and did the first thing that came into her mind: raise the collective to stop the descent. But if she had been properly trained and knew what was going on, she would have reacted properly by simply pulling the cyclic back to slow down and reduce the descent rate.

As a result, a helicopter is destroyed, the NTSB is required to waste time and resources to investigate, and a student pilot, although lucky to be alive, has an accident on her record.

Literacy Might Be a Good First Step

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I’ve received messages and comments that were barely literate, but this one takes the cake.

I just received the following e-mail message from someone who had likely read one or more of my posts about flying helicopters or the helicopter job market:

Bare in mind that I have never flown a acraft of any type before…… I want to get into flying a turbine helicopter (of my owne) and I live in Mississippi. Everything I find online about schools is very, for lack of a better term eather full of crap and or confusing as all hell. and there are more schools than you can shake a stick at, but all have a list of requierments a mile long just to take a class. I ask you because you are already a pilot, and might atlaest be able to give me a guide line and rough idea with out all the bullcrap to confuse it. I need to know what I have to do to get a helicopter pilot licence, both for comercial and privet flying. where I can go to do so. and a high ball estimit of what it will cost me. could you please help me on this matter?

I did not edit the above. This is exactly how I received it, copied and pasted into my blog editing software.

Those of you who don’t see a problem with the above…I have one question: what the hell are you doing here? My writing must seem like Greek to you, since I tend to write at a Grade 8 level or higher.

While I don’t know anything about the age and background of the author of the above (other than the tell-tale Mississippi comment), I like to think that he’s in at least eighth grade. (And, for the record, although I live in Arizona, I didn’t go to school here.)

I had to read it three times to understand what he was getting at. I can see why he finds online information “confusing as hell” — his understanding of properly spelled words in the English language is likely minimal.

This is the kind of e-mail I get sometimes.

You know, I want to help people achieve their dreams. I really do. That’s one of the reasons I blog about the things I do. I can do these things, so it follows that other people can, too.

But I can’t tell people how to perform miracles.

This guy is doomed before he starts. I know that if I were hiring and someone sent me an e-mail or cover letter or (heaven forbid) resume with as many errors as the above message, I wouldn’t even bother to answer it. This guy’s failure to put together a single error-free sentence makes me wonder how he’ll fare when it’s time to study the POH (that’s Pilot Operating Handbook) for the turbine helicopter he wants to fly.

I’ve said it before and I’ll say it again: you cannot get anywhere in life without basic communication skills — including writing skills. These days, with spelling and grammar checkers built into half the writing software out there, there’s no reason to send out a communication like the one above.

You want a career as a pilot — or anything else? Learn how to communicate first.

And, for the record, it is not my intention to ridicule the author of the above. If I wanted to, I would have included his name and e-mail. (Even I’m not mean enough to do that.) I’m just using his communication as an example. I’m hoping that my e-mailed response to him — that it’ll cost $40K to $80K to get the ratings he needs to fly helicopters for a living — scares him into more reasonable aspirations.

Like getting his GED.