Uncategorized Archive

No two are the same

Thursday, August 6th, 2015

Recently Mick Cullen, of the Rotary Wing Show, invited Hover Power editor Ian Twombly and me to a podcast interview (episode 31 if you want to check it out). The end of the podcast had an offer for an AOPA hat, given to the first three listeners who offered topic suggestions for Hover Power. Thanks to Lee Rilea, who asked us to describe: flight characteristics of different helicopter types, and how pilots can prepare for them.

Each model helicopter is a unique and aerodynamically complicated machine, and all have differences the pilot must be cognizant of. Even sister ships have differences, such as the 62-inch versus the 65-inch tail rotor in the Bell 206 series. The differences can be subtle too; simply changing low to high clearance landing gear can alter slope limitations for a particular aircraft.

With proper training and proficiency these aircraft differences are manageable. While the Rotorcraft Flying Handbook is a good general resource, the Rotorcraft Flight Manual and Factory Training Manuals will have specific information for a particular helicopter.

I will cover a few differences, and Hover Power blog readers can add more in the comment section.

Main rotor systems

An example of a unique flight characteristic involving the main rotor is the rigid rotor system of the BO-105, BK117 and EC145. Unlike most other rotor systems, which are semi-rigid or fully articulated, it is capable of negative Gs. Sounds great, but as in most cases there are compromises, and mast bending is one. The rotor blades, rotorhead, and mast are attached together rigidly without hinging capability. Turbulence, abrupt or extreme pilot control input, settling with power, and slope landings can all generate high mast bending. Think of the rotor system, mast, transmission, and airframe as one solid unit without any ability to hinge, with the mast actually bending when there is a shear force between the airframe and main rotor. A strain gauge is mounted inside the mast and is connected to the mast moment indicator on the instrument panel, so the pilot can assure mast-bending limitations are not exceeded.

Let’s also consider Vne and retreating blade stall in the rigid rotor system. Some aircraft are fairly docile when encountering retreating blade stall, just a gentle shutter as the aircraft slowly pitches up or rolls, but not the BO105.

One day, while flying a BO105CBS across the mountains of New Mexico I experienced retreating blade stall in a rigged rotor system for the first time. I had just a few hours in type, but fortunately was flying with an instructor. As one increases altitude, the Vne will decrease accordingly and we had made that adjustment. However, as any mountain pilot can tell you, turbulence and altitude can make for a wicked combination. A strong updraft can momentarily increase the angle of attack on a blade, creating a retreating blade stall condition. There is nothing gentle about this in a rigid rotor system, as I found out that day. We hit a particularly strong updraft at about 7000 feet, when the nose pitched up abruptly. Forward cyclic had no effect, and in fact would not even move. I didn’t recognize this as a retreating blade stall condition, but the instructor did and immediately decreased collective or we probably would have looped. Decreasing the collective removed the stall condition caused by the updraft, and allowed the cyclic to regain its effectiveness. I learned to always have my hand on the collective when flying the BO105 over mountains or when the possibility of turbulence existed. I also learned a smoother pitch attitude could be maintained in the BO105 by actually flying the collective with slight cyclic inputs. Increase collective slightly to pitch up and decrease collective slightly to pitch down, resulting in a smoother ride through turbulence.

Another characteristic of the BO105 is a phenomenon called “divergent roll.” In a descending low airspeed right bank, there is a tendency to run out of left cyclic. When turning right, one needs more and more left cyclic to maintain the bank angle without having it increase. One can reach the point where the cyclic is hitting the pilot’s left leg, which is already pinned against the center console. The remedy is left pedal, which is responsive in correcting this condition. This is not considered a cause for concern among experienced BO105 pilots, because they are prepared and knowledgeable of this characteristic.

The tail rotor and Notar

All helicopters with a tail rotor or Notar (MD Helicopters’ acronym for No Tail Rotor) are susceptible to a loss of tail rotor effectiveness in a hover or at low speed. The effectiveness of the tail rotor is dependent on a stable and relatively undisturbed airflow. There are many factors that can affect this airflow and cause LTE, such as main rotor downdraft and vortices, density altitude, gross weight, turbulence, forward airspeed, and relative wind speed and direction. Some of these factors contribute to the need of increased tail rotor pitch, resulting in a higher power requirement and a higher angle of attack of the tail rotor blades, leaving less thrust available in reserve. Other factors can disturb the airflow through the tail rotor creating a vortex ring state, such as the relative wind direction; also known as the critical wind azimuth. No two model helicopters are alike and the pilot must know the aircraft’s tail rotor limitations, typically found in the limitation and performance sections of the RFM.

A pilot flying at lower altitudes may not give the critical wind azimuth much thought, such as during a hover taxi in a right quartering crosswind. However, an increase in density altitude and gross weight also increases the required pitch from the tail rotor, making it more susceptible to LTE when wind is from the critical azimuth direction.

A different technique may be prudent to account for the increased susceptibility of LTE in certain aircraft. The MD902, with its Notar system, is more prone to LTE than any other aircraft I’ve flown when operating at altitudes over 3000 feet and at high gross weights. When hovering at altitude in the MD902, I would avoid any right crosswinds during takeoff, approach or hover; even to the point of doing a 270 degree turn at a taxi intersection rather than the 90 degree with a right crosswind. It is a manageable characteristic, as one learns “everything is into the wind above 3000 feet” in a MD902.

Another aircraft I’ve flown prone to LTE were the early Bell 206s. These had the smaller 62-inch tail rotor (Bell later went to the 65-inch tail rotor), and the early flight manuals did not have the critical wind azimuth chart or its inclusion in the hover ceiling charts.

HP chart 2

For this BH206, the critical wind azimuth area is depicted to be from 050 to 210 degrees, and the hover chart shows the altitude, temperature, and gross weight that area would be designated the avoid area B.

Gross weight

Lighter helicopters can respond faster to pilot input than heavy helicopters. An acceptable descent rate below 1,000 AGL for an AStar 350 (GW of 4960 lbs) would not be acceptable for an AW139 (GW of 14994 lbs). Just as a heavy truck on a highway needs more time to accelerate and decelerate, so do larger aircraft. The pilot of a heavy helicopter needs to recognize a negative trend sooner, such as an unacceptable descent rate on short final, as it will take more time to correct.

I typically fly out of Houma, Louisiana, which is probably the busiest airport in the United States for civilian helicopter operations, with over 71,457 helicopter landings in 2014. One can watch variations in approaches and departures for different helicopters. The most obvious variables are the approach speed, profile and descent rate. Heavy helicopters, such as the Sikorsky S-92, make a slower and steeper approach than lighter aircraft. Each pilot is flying their specific type helicopter in accordance with the RFM and company flight standards, and it’s a good opportunity to see how this varies among different helicopters.

What differences have you experienced? Tell us in the comments section.

Slinging IFR

Tuesday, June 30th, 2015

Flying helicopters IFR with a sling load presents unique challenges, requiring specific skills of the pilot.  One must obviously be able to control the helicopter without any outside visual references. Less obvious, one must also be able to correctly interpret the instruments, which reflect both the behavior of the load and the orientation of the helicopter. A Class B external load (sling load) is one that is free of the earth’s surface and is attached to the helicopter by a synthetic or wire line. The pilot is “flying” both the helicopter and the load, which at times can seem to have a mind of its own.

Today slinging IFR is not a common practice, though there was a time on the North Slope of Alaska where it was employed regularly. I thought it might be interesting to look at this operation in some detail.

 

An AW139 lifts off for an external load training flight out of Deadhorse Alaska.  Photo by Dan Adams

An AW139 lifts off for an external load training flight out of Deadhorse Alaska. Photo by Dan Adams

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Controlling the sling load

Normally one can see the external load, and make the necessary corrections. Lateral swinging is more common than a fore-aft motion or a circular motion, so we will focus on that. A quick lateral cyclic input towards the load, just as it reaches its apex, moves the aircraft over the load neutralizing its motion. You are essentially moving the aircraft over the load after it has swung out to the side. This dampens the movement of the load and stabilizes it. However, when flying IFR the instruments must be used to indicate the loads’ position and movement. The best way to learn how the instruments reflect the movements of the load is during VFR flight, when the load and gauges can be seen together.

Flying IFR with a sling it is important not to make corrections reflecting the gauges as one normally would, but instead understand exactly what the load is doing beneath you. The attitude indicator reflects rhythmic changes in bank angle from the load tugging the helicopter laterally side to side, as does the ball in the inclinometer. The inclinometer is used to indicate when and how much lateral cyclic input is necessary for a correction, though there is a natural lag. The load will reach its apex prior to the inclinometer, and the pilot must compensate for this natural lag. When the ball starts to swing out of center to the right and is about half way from its apex, the load is almost at its apex to the left, the pilot then uses left lateral cyclic as a correction. The rhythmic oscillations in the attitude indicator and inclinometer reflect the movements of the load, and the average of these movements are the actual orientation of the aircraft.  The pilot learns to mentally average these oscillations in order to control the pitch, roll, and yaw of the aircraft itself.

“An ounce of prevention is worth a pound of cure”, so one learns to make flight control inputs very smoothly so as to not aggravate the load. Turns are initiated slowly, and half standard rate turns are sometimes prudent.

Determining cruise airspeed

Another consideration is determining the target airspeed at which to fly.  This must be greater than Vmini (minimum IFR speed) and less than the loads effective Vne. While the aircraft will have an external load airspeed limitation, this may not be possible if the load is unstable at a lower speed. Many loads cannot be flown at the external load Vne, and the effective Vne must be determined. As the pilot slowly accelerates during takeoff, the load is carefully watched prior to IMC to determine what airspeed above Vmini the load can be flown at. Once that airspeed is determined, it is maintained for the entire flight.

Should the load show signs of instability below Vmini or only slightly above so as to not provide a safe and adequate airspeed window, the takeoff is aborted while still VMC.

One should be sure of a load’s stability and capability at a safe airspeed prior to IMC, and one should only fly known loads in IFR or at night. A known load is one that is similar to one previously flown during the day. The load characteristics are predictable and stable.

Autopilots and external load operations

Autopilots and external loads don’t usually mix, and many Rotorcraft Flight Manuals prohibit autopilot coupling during external load operations. The autopilot can be too abrupt in pitch attitude and roll, particularly when initiating and terminating turns. A pilot can make changes with a more gentle touch; such as slowly entering a half-standard rate turn when necessary. The autopilot can be used for stability augmentation; it just shouldn’t be coupled to the flight director directly controlling the aircraft.

Horizontal and vertical situational awareness

Class B sling loads can be jettisoned, either intentionally or unintentionally. The hook release is typically electric and controlled by the pilot. Under normal operation the load is released once it has been placed gently on the ground; however, in the case of an emergency the pilot may opt to release it in flight. Due to the possibility of the load being released in flight, persons or property are never overflown. This requires horizontal situational awareness; easy enough VFR, but IFR is another matter. Fortunately, the North Slope of Alaska provides assurance due to its desolate nature.

Vertical situational awareness must also be considered, not just for the helicopter but also for the load hanging underneath. With the typical 25 to 50’ line, the altitude of the load isn’t a factor in cruise flight; however, during the instrument approach it must be considered.

The Instrument Approach

As much fun controlling the helicopter and load may be in IFR conditions, eventually we do need to land. For that we need to fly an instrument approach. Let’s stick with the North Slope of Alaska, using the Deadhorse (PASC) ILS 05 as an example, using a little simple math.

A load 5 feet high hanging on a 50 foot line would require a 55 foot adjustment factor to the decision altitude. For the Deadhorse ILS, this means increasing the decision altitude of 267 feet to 322 feet, and ALS conditional altitude of 167 feet to 222 feet. It would also be prudent to include this 55 foot altitude adjustment into your preflight IFR planning.

Final Thoughts

While flying slings IFR is no longer common, the training for IFR slings still occurs. Having the skill and confidence to be able to fly a sling IFR is vital should unforecasted adverse weather be encountered, not unheard of on the Alaskan North Slope where the weather can change quickly. Airports and options are few and far between north of the Brooks Range of Alaska. These skills also translate well and are employed for night sling operations, which are still done on a regular basis.

Owners, pilots, and owner pilots

Tuesday, June 23rd, 2015

I’ve been thinking a lot lately about the goal differences between helicopter owners and pilots. This could be because of my annual involvement in cherry drying work which is one of the few kinds of work that probably appeal more to owners than pilots.

What Owners Want

I think I can safely say that all owners–whether they own and fly for pleasure or own primarily as part of their business–want to keep owning the helicopter. That means keeping costs low and revenue–if any–as high as possible without jacking up costs so they can continue to meet the financial obligations of ownership: insurance, debt service, storage, required maintenance, registration, taxes, etc.

Of course, if a helicopter is owned as part of a business, the owner’s main goal is probably to build that bottom line. That means maximizing revenue while minimizing expenses. While every helicopter has some fixed costs that come into play whether it flies or not–insurance, hangaring, annual maintenance–an owner can minimize costs by focusing on work that pays even if the helicopter doesn’t fly. That’s why you can lease a helicopter with a monthly lease fee that’s independent of hours flown and why certain types of agricultural work–cherry drying and frost control come to mind–pay a standby fee that guarantees revenue even if the helicopter is idle.

As an owner, I can assure you that there’s nothing sweeter than having your helicopter bring in hundreds or even thousands of dollars a day while it’s safely parked at a secure airport or, better yet, in a hangar.

If the helicopter does have to fly, the owner wants the highest rate he can get for every flight hour and the lowest operating cost. How he achieves those goals depends on his business model, the equipment he has, the services he offers, and the pilots who do the flying.

What Pilots Want

What pilots want varies depending on where they are in their career.

  • Student pilots want to learn. Their goal is to learn what they need to and practice it enough so they can take and pass checkrides. Because they’re paying full price for every hour they fly, they’re not necessarily interested in flying unless it enables them to practice the maneuvers they need to get right on a check ride.
  • New pilots want to fly. Period. Their primary interest is building the time they need to get their first “real” flying job: normally 1,000 to 1,500 hours PIC. They’ll do any flying that’s available. And even though commercial pilots and CFI may be able to get paid to fly, some will fly for free or even pay to fly if the price is right. Indeed, I’ve had more than a few pilots offer to fly for me for free, which makes me sad.
  • Semi-experienced pilots want to build skills. Pilots who have had a job or two and have built 2,000 hours or more of flight time are (or should be) interested in doing the kind of flying that will build new skills or get practice in the skills they want to focus on for their careers. So although they still want to fly, they’re more picky about the flying they do. They’ll choose a job with a tour company that also does utility work over a job with a tour company that doesn’t, for example, if they’re interested in learning long-line skills.
  • Experienced pilots want flying jobs doing the kind of work they like to do and/or paying the money they want to receive for their services. Pilots with a good amount of experience and specialized sills are often a lot pickier about the jobs they take. For some of these pilots, flying isn’t nearly as important as pay and lifestyle. A utility pilot friend of mine routinely turned down jobs if he didn’t like the schedule, just because he didn’t like being away from home more than 10 days at a time. But dangle a signing bonus in front of him and there was a good chance he’d take it.

Of course, there are exceptions to all of these generalizations. Few people fall neatly into any one category.

But what you may notice is that most of them need to fly to achieve their goals, whether it’s passing check rides, building time, learning skills, or bringing home a good paycheck.

And that’s how they differ from owners.

Owner Pilots

I’m fortunate–or unfortunate, if you look at my helicopter-related bills–to be both an owner and a pilot.  I’ve owned a helicopter nearly as long as I’ve been flying: 15 years.

The owner side of me is all about the revenue. I love agricultural contracts that let me park the helicopter on standby and collect a daily fee for leaving it idle. Every hour it doesn’t fly is another flight hour I can keep it before I have to pay that big overhaul bill. (I own a Robinson R44 Raven II, which requires an overhaul at 12 years or 2200 hours of flight time, whichever comes first.) It’s also an hour I don’t have to worry about a mishap doing the somewhat dangerous agricultural flying work I do.

The pilot side of me wants to fly. I love to fly. I bought a helicopter because I felt addicted to flying and needed to be able to get a fix any time. (The business came later, when it had to.)

Owning a helicopter means having a safe place to keep it when it's not flying.

Owning a helicopter means having a safe place to keep it when it’s not flying.

And because I’m an owner, with ultimate say over how the helicopter is used, and a pilot, with a real desire to fly, I can pretty much fly where and when I want to. But when the fun is over I’m the one who has to pay the bill.

Being an owner pilot gives me a unique perspective, an insight into how owners and pilots think and what drives them.

Working Together to Achieve Goals

In a perfect world, owners would think more about pilots and work with them to help them achieve their goals. That means helping them learn, offering them variety in their flying work, and paying them properly for their experience and skill levels.

At the same time in that perfect world, pilots would think more about owners and work with them to help them achieve their goals. That means flying safely and professionally, following FAA (or other governing body) regulations, pleasing clients, taking good care of the aircraft to avoid unscheduled maintenance and repair issues, and helping to keep costs down.

What do you think? Are you an owner or pilot or both? How do you see yourself working with others? Got any stories to share? Use the comments here to get a discussion going.

The K-Max returns

Thursday, June 18th, 2015

There’s good news from Bloomfield, Connecticut-based Kaman Corporation. The company announced recently it plans to restart production of the heavy-lift K-Max. An initial conservative plan includes building 10 helicopters, primarily for international buyers. Deliveries are planned for early 2017.

Known for its unusual twin intermesh rotor system, the K-Max is capable of lifting an external load of 6,000 pounds. That gives it the distinction of also being able to lift more than it weighs. Empty weight is 5,145 pounds and max gross takeoff weight is 12,000 pounds. It’s purpose-built external load roots are clear in the bubble side windows and relatively small, single-seat cockpit.

Fewer than 40 aircraft were built during the production run from the early 90s to when the line was shut down in 2003. Of those the Marines have two they use as unmanned cargo aircraft (photo below). Kaman launched that project in cooperation with Lockheed Martin, and it was nominated for the Collier Trophy.

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Master your environment

Tuesday, June 9th, 2015

Helicopter pilots work in an amazing, ever-changing environment. The skills necessary to accomplish the task at hand require a high level of concentration, ability, and finesse. Whether it is flying circles around some of God’s greatest work, air medical operations, or instructing the next generation of helicopter pilots how well you utilize your skills can easily be determined by how aware you are with all components of your flying duties. In other words, you must be fully involved and a master of your environment.

WHAT IS YOUR ENVIRONMENT?

You can’t master what you don’t know. Environment can be defined as “the setting or conditions in which a particular activity is carried on.” The activity is easily defined as flying, however, it is the setting or conditions that can make or break you. It would be impossible to list all of the components that define a particular flying environment but several are common to most, if not all, flight operations. These mainstays include: aircraft, airspace, weather, and regulations.

AIRCRAFT If you really want to get to know your aircraft, its systems, and emergency procedures, make a plan to review the Rotorcraft Flight Manual on a regular basis. Pick a chapter in the RFM each month of the year and review it religiously. Know the RFM inside and out.

AIRSPACE I used to wonder why designated pilot examiners and check airmen were so stringent about airspace during checkrides. After a few years of operational flying and getting the life scared out of me by people that didn’t know understand it, I realized why this was a pet-peeve of many examiners. Not knowing airspace is like driving in a foreign country with road signs in a language you can’t begin to comprehend. If it has been a while since you actually used a sectional chart to navigate the various classes of airspace here is a good way to humble yourself; on one of your next flights turn the GPS off. Use good old fashioned pilotage and dead reckoning to find your way. Ask yourself where you are on the chart, where you came from, and where you are going. What airspace are you travelling through? What are the weather minimums? What equipment is required? Transponder? Who do you need to talk to? On what frequency? You get the idea. If you are going to master your environment you must know everything about the airspace you are transiting in and out of.

I have a rule about avionics and eyeballs that are in any aircraft I am flying. No avionics or eyeballs ride for free. If you got’em use them! As an example, if you have two GPS systems use both of them. Use one for your destination and the other for a nearby airport close to your departure area that has an instrument approach in the event you inadvertently fly in to the clouds shortly after take-off.

WEATHER If you think all you need to know about weather comes from those ridiculous questions on the FAA knowledge exams you are mistaken. Most areas experience some sort of regional microclimate. Get to know the weather patterns in your area and when to expect them. If you are flying in an area unfamiliar to you, reach out to other helicopter pilots and pick their brains on local weather patterns. The accident statistics are full of stories about helicopter pilots that didn’t have a working knowledge of local weather patterns.

REGULATIONS In this day and age of technology the current regulations can easily be placed in electronic format on all of your neat gadgets. Know all of the regulations that apply to your particular operations and know them well. If you don’t understand a particular regulation, seek clarification. Wiggle-room has no place when The Man is ready to take enforcement action against you. A quick survey of NASA reports shows several high-time pilots making mistakes involving regulations. Like the Rotorcraft Flight Manual, the federal regulations pertaining to your certificate privileges and operating activities need a periodic review.

HOW TO STAY SHARP? Whatever you do, don’t lose the awe factor. Not long ago I read a story about a 39-year physician. This fellow was in his late 80’s, and he still went to the office every day. His friends and family tried to get him to retire, but he simply refused. He had invented a procedure that he had performed more than 10,000 times. He was asked in an interview if he ever got tired of doing it, if it ever got old. He said, “No. The reason why is because I act like every operation is my very first one.” If you find yourself losing that awe of spooling up and pulling pitch, it may be time for a break. Taking pride in what you do and doing it with excellence can foster an attitude that enables you to master your environment.

OSAPs, HEDAs, and ARAs oh my!

Tuesday, June 2nd, 2015

Imagine being able to create an instrument approach while en-route, and then fly the approach down a minimum of 200 feet and 3/4sm. Not as crazy as it sounds. Here’s why:

IFR helicopters do this regularly, supporting the offshore petroleum industry in the Gulf of Mexico, flying as far as 200 miles offshore to land on ships, drill rigs, spars, and platforms.  All in accordance with Advisory Circular 90-80B: Approval of Offshore Standard Approach Procedures (OSAP), Airborne Radar Approaches (ARA), and Helicopter En Route Descent Areas (HEDA).  The title is certainly a mouthful, and the 58-page document can also be a little daunting. It helps to look at one in action, in this case the popular Copter Delta 30 OSAP, pronounced as “Oh-Sap.”

Before first light, prior to start-up for an IFR flight offshore, which will incorporate an OSAP approach to the destination rig.  Photo by Alex Geacintov

Before first light, prior to start-up for an IFR flight offshore, which will incorporate an OSAP approach to the destination rig. Photo by Alex Geacintov

The Copter Delta 30 OSAP is one of five charted templates in AC90-80B that a pilot can adapt to almost any location offshore. It requires specific two pilot crew training, GPS, ground mapping capable radar, and radio/radar altimeter. It is a SIAP (special instrument approach procedure), and therefore also requires FAA authorization.

While en-route, destination weather is rechecked via radio or satellite phone. If the destination doesn’t have approved weather reporting, normally required under part 135, some operators have an FAA authorization to use remote reporting stations. Operations Specifications are regulatory and issued by the FAA, with some being more restrictive and some less restrictive than the associated FAR. Think of them as an extension of the FARs for specific operators. In this case the Op Spec is less restrictive, which is a good thing because although there are some AWOSs  offshore, there never seem to be enough.

The OSAP Delta 30

The OSAP Delta 30

Wind condition at the destination is used to determine the approach course, which must be into the wind. A DWFAP (down wind final approach point) is typically created 7nm downwind from the destination, on the final approach course. The DWFAP can be created anywhere on the final approach course, as long as it is between 5 and 10nm from the destination. Depending on the en-route direction, a course reversal may be necessary in order to establish the helicopter inbound on course at the DWFAP. All this is planned and created while en-route, and then programmed into the Flight Management System or GPS. Radar in ground-mapping mode is used to determine there are no obstacles within .5nm of the final approach course. The final approach course can be adjusted for obstacles, just as long as it is within 10 degrees of the wind.

When 40nm or less from the destination, a cruise clearance is requested from ATC. This allows an immediate descent to MEA, an eventual descent to 900 MSL 20nm out, and a clearance to fly the approach and missed approach, if necessary.

Once established inbound at the DWFAP, at or below 70 knots (ground speed), a descent from 900MSL to 500MSL can be initiated.

If there are no obstacles within .5nm of course, and the radar and GPS are in agreement within .2nm for the destination target, a further descent from 500MSL to 200RA (radio altitude) can be made.

Radio altitude, from a radio or radar altimeter, is the actual height of the aircraft above the surface, in this case the ocean. The radio altimeter is used to determine the height, while the radar is used to identify obstructions. It’s a dynamic environment and just because an approach was clear of obstacles the day before doesn’t mean a drill ship wasn’t repositioned overnight.

At 1.1nm out, a right or left 30-degree turn is made to avoid overflying the destination, hence the name “Delta 30”. The heading change still has the aircraft converging with the destination, with the MAP (missed approach point) being .6nm away. At the MAP, one can proceed visually to land or go missed approach.

An OSAP is a great procedural tool for the trained two-pilot IFR crew in the offshore environment, providing precision approach-like minimums.

(These views and opinions are my own and do not necessarily reflect the views of Era.)

 

The rig looms ahead after shooting an OSAP Delta 30 instrument approach.  Photo by Paul Patrone

The rig looms ahead after shooting an OSAP Delta 30 instrument approach.  Photo by Paul Petrone

Hiller returns

Wednesday, May 20th, 2015

Few manufacturers are making personal helicopters these days, and those that are have to charge a hefty price to make up for the relatively small volume. (One could argue that Robinson’s R22 is reasonably priced, but the per-hour cost is steep). That’s why United Helicopter‘s work with old Hiller airframes is so enticing.

United is taking Hiller’s ubiquitous UH-12B and C models and completely restoring them from the canopy to tail rotor, a process that takes 1,500 hours of labor. The company restores all components, provides custom paint and interior choices, and sells it for roughly $159,000. Prices vary depending on options, such as doors, aux fuel tank, ground handling wheels, and so on. Donor airframes can be either supplied by the customer or rolled in to the purchase price. An employee at Sun ‘n Fun said they have around half a dozen ready to go, and that many more are in barns and hangars scattered around the country.

Hiller’s UH-12 is one of the great early helicopter designs. First developed in the late 1940s, it went through a number of airframe and engine changes over the years. That it was used as a primary trainer for the Army should speak to its robustness. The B and C models, which United focuses on, are powered by Franklin engines. The employee said they work on those two because parts are easy to find and they offer the best mix of performance and value. Both have a rotor system with an extremely high amount of inertia. Perhaps best of all, the tail rotor is the only time limited component. Only four components are life limited–the tail rotor rod, blade, and yoke assemblies, and the tail rotor tension torsion bar. Each has to be pulled at 2,500 hours. The Franklin engine is a bit of a sticking point in that it has a lower 1,200 hour overhaul interval.

Ignoring the life limited components for a bit, the per hour operating cost is around $150, including insurance and annual. That assumes 100 hours of flying. Throw in those components and the price goes up a bit, but still well below other competitors. And since its able to carry 600 pounds of people with full fuel across three seats, there are lots of cabin options as well. That’s pretty impressive coming from a guy who designed his first helicopter before most kids graduate high school.

Have you flown a Hiller? Give us your impressions in the comment section.

Flying on coconut time

Wednesday, April 29th, 2015

Fresh coconuts everywhere! We hadn’t had any fresh food in the last couple weeks, unless you count coleslaw; nothing lasts longer at sea than cabbage and carrots. I started up the Bell-Soloy helicopter to begin shuttling crew to a Pacific island atoll. We were going grocery shopping.

 

An uninhabited Pacific atoll

An uninhabited Pacific atoll

 

It was 1988 and we had been at sea almost two months and the holds were far from full. My job was to fly the helicopter in search of tuna, and then help catch them by herding them into the net. We were to fill the Maria Rosana II with about 1,300 tons of tuna. She was a fast 225-foot tuna clipper with a crew of 23, five speedboats, and a helicopter. We used a seine net almost a mile long and 500 feet deep, with one end attached to the skiff and the other to the ship. When setting the net, the skiff was released and the tuna boat would make a huge circle back to the skiff. A cable, which ran through metal rings all along the bottom of the net, was then winched, closing off the bottom of the net. The net was then pulled through a power block until the tuna were packed tight. They were then scooped out and funneled through a chute into a hold for freezing. Simple enough, except tuna are 47 mph fast and lately schools had been hard to find. Holds full or not, we would soon be low on ship fuel and have to return to port. After months of hard work, we could now have a little enjoyment. After all, how many people get to land on uninhabited Pacific atolls?

After shuttling several guys to the island, I shut down the helicopter and started walking around. The birds had never seen humans and were unafraid of us; we had to zigzag to avoid stepping on them. As I walked the oceanside I saw multitudes of fish and some very large and inquisitive moray eels. The lagoon side was full of baby sharks. It was pristine and untouched.

Back at the helicopter, the guys had already accumulated a very large pile of coconuts. The copilot side door had been installed (no dual controls), so we were able to fill that entire side of the cockpit with about 20 coconuts.  I then flew back to the ship, landed and then reached over to pop the door open, watching most the coconuts roll out onto the deck. The mechanic then reached in and got the few remaining stragglers. After many trips we had a few hundred coconuts all over the helideck. The helideck had a metal lip about 4 inches high around the edge and was cambered, which caused the coconuts to roll away from the helicopter. Soon, there was barely enough room to land.

 

Just before start up and flying coconuts to the boat

Just before start up and flying coconuts to the boat

 

Later that day our pleasure was ruined by learning we had to waste a day meeting up with a sister ship to get a needed part. Seems one of the refrigeration solenoid valves was bad. Our mood was quickly restored when some genius figured out gin went really well with coconut milk, likely the helicopter mechanic.

The next day, I flew to the other boat to get the part and while the other pilot cleared the deck, we chatted on the radio.

“Oh by the way, the stabilizer is busted” he said. The stabilizer is a U-shaped hydraulic flume tank near the stern, married to the inside hull of the boat. Tuna clippers are long and sleek; so without a working stabilizer there isn’t much roll stability.

I knew what that meant. But I asked how bad it was anyway.

“Well she is rolling a bit in this swell, just pick your moment and you should be okay.”

“How much is rolling a bit?” I said. He was really getting my attention now.

“Oh, about 30 degree each way, but she’ll settle down once in a while for you to land. No problem, just get the timing right.”

Nearing the boat, I could see they had recently set the net and were laying stern-to in a following swell. This was worst possible position and she was rolling heavily, but I noticed there were pauses. I made an approach, trying to gauge and anticipate the roll. Once over the actual helideck, it was a combination of looking at the horizon and down at the landing area. The deck was moving up and down a manageable 6 feet, but the roll was bad. It was necessary to wait until the deck was fairly level and within the slope limitations of the helicopter, and then get it down fast before the next roll.  As soon as the floats touched down, I quickly bottomed the collective before the next roll. The mechanic rushed out with cargo straps, cinching us to the deck, and I began the two-minute cool down. The ship then took a big roll, which was not a lot of fun; an idling helicopter on a 30-degree slope 35 feet above the ocean. I doubt I could ever get used to that. Soon we shut down and I went into the bridge to look at the inclinometer gauge, which measures the amount of roll. I could hardly believe it, but it was showing regular rolls to 28-degrees both ways; a 56-degree swing.

After the part had been loaded, I climbed back in and started the turbine. After bringing the rpm up to 100 percent, I signaled the mechanic to release the last remaining cargo strap. Waiting for the ship to level, I then applied max power and nosed her over.

After I cleared the ship, I radioed the other pilot. “Hey man, how long has it been like that?”

“It went out at the beginning of the trip about a month and half ago,” he said.

“ Well, if there was a tuna boat helicopter pilot hall of fame I would vote for you.”

“Ha, well the first week is rough, but you get used to it,” he said.

I wasn’t so sure I would get used to it.  Rick was one of our most senior pilots and had been doing this for more than six years and was very good.  I was sure glad our stabilizer was working, and made a mental note to buy some drinks for our chief engineer the next time we hit the beach.

The rest of the trip was uneventful, until we blew up one of the helicopter’s floats with a ¼ stick of dynamite….buts that’s for another blog.

(These views and opinions are my own and do not necessarily reflect the views of Era.)

Flying to the ship

Flying to the ship

Why wait?

Wednesday, April 15th, 2015

We have a lot of great safety related resources in the industry. If you are flying professionally and have made it to that career goal you set years ago you may be familiar with most of these great resources. However, for reasons I cannot fathom many of these great resources are only introduced after a pilot makes it to his or her career position, whether it is HEMS or another side of the industry. This has to change!

Any HEMS pilot is all too familiar with a risk assessment (RA) tool. In fact, the regulations now require their use. The use of a risk assessment tool is a reminder that every flight has some level of risk associated with it and can sometimes open one’s eyes to previously unforeseen safety culprits. Say what you will, but a properly utilized risk assessment tool can be a tremendous asset when utilized correctly. So, why wait? Why are we waiting until a pilot reaches that first HEMS job at 2,000 or more hours to introduce them to this risk management tool? Why do we have to wait until he hits the 2,000 hour mark to make him safe and professional?

So much time is spent with a new primary flight student on learning to fly that many important facets are being neglected. Any CFI will remember studying the laws of learning and particularly the law of primacy. It states that those things learned first tend to stick with the student throughout his or her flying career. Instead of waiting for 2,000 hours to pass, why not teach the importance of the risk-management process (and tool) from the very beginning? And I do mean from the very first flight; the new student watches the CFI conduct a preflight risk assessment and explains what he or she is doing and more importantly why they are doing it. I have heard of just a couple flight schools utilizing risk assessment tools with students for flight training and I strongly applaud them! Hopefully others will follow suit.

We have other amazing resources for students. The United States Helicopter Safety Team (USHST) does a great job of conducting and providing analysis of helicopter accidents for the purpose of distributing “lessons learned” type of information. This group has produced dozens of nice training bulletins and fact sheets. They should be mandatory reading for any new student. But sadly I am finding that many beginning pilots have no idea what the USHST is. Why wait? CFIs should take the time to introduce the USHST to all of their students. Their website provides mounds of good useful reading material.

Unfortunately air medical related accidents have surfaced on a near regular basis in the United States. Many of the accidents involve inadvertent entry into instrument meteorological conditions. Many in the industry have taken note and developed various mitigation strategies. One of those strategies is an absolutely ingenious concept developed by the National EMS Pilots Association (NEMSPA). This group of highly talented professionals created the Enroute Decision Point (EDP). Simply stated, this concept says that pilots should establish a “trigger-point” when flying in less than perfect weather conditions. Their recent campaign has pushed a “down by 30” concept. This philosophy says that when a pilot finds himself in a deteriorating weather condition that requires him to reduce airspeed by 30 knots it is time to land or turn-around–or go IFR if capable. This is a great concept so, why wait? Why are we as an industry waiting until a pilot reaches the HEMS pilot hour requirements before we teach him this life-saving technique? Inadvertent IMC accidents and are not limited to the HEMS part of the industry.

And finally, Matt Zuccaro and the other fine folks at Helicopter Association International (HAI) have developed the “Land & Live” program. This concept stresses the importance that a pilot should land the helicopter before the situation becomes an emergency, such as in the case of a chip-light, low-fuel, or weather situation. The program has a strong emphasis towards commercial operators to not have a punitive culture for pilots that use good judgment and make the decision to “Land & Live”. This concept may sound like common-sense to many but all too often we read of situations where the outcome could have been entirely different had a pilot used this simple concept. So, why wait? Why not introduce this philosophy very early on in a student’s training?

This article has covered just a sample of the various philosophies and techniques that are being used by the most experienced pilots in our industry. If I haven’t made it clear, we as an industry need to start teaching these and other great safety practices to student pilots very early in their training.

Fly the cloud: Controlling whiteout and brownout

Wednesday, April 8th, 2015

When landing helicopters in potential obscuration conditions, there are two techniques that have worked well for me over the years.  Whether the rotor wash kicks up loose earth causing a brownout or snow causing a whiteout, the techniques used to mitigate the obscuration are alike. While best to avoid these conditions by having ground personnel pack the snow, wet down a dusty area or find another landing zone, there are ways to manage the risk.

Unless you have a wheeled helicopter and a surface for a safe run-on landing, you likely need to land with zero groundspeed. This can be done safely using one of these techniques, without the risk of losing visual references and basically becoming IMC in a hover.

The Shallow Approach

The shallow approach is my preferred method in flatter terrain and a large area without obstructions.

Before discussing the actual approach, the “rotor wash contact point” should be understood. This is the point where the rotor wash meets the ground, and where the obscuration is formed. Its position, relative to the aircraft, is a function of aircraft airspeed, tilt of the rotor disc, and surface winds. All these variables affect where on the ground the obscuration will be formed and where it will drift after being formed. For example, decreasing airspeed or moving the cyclic aft will move the rotor wash contact point closer and more beneath the aircraft. The pilot can control the position of the obscuration cloud, by managing airspeed and the fore/aft position of the rotor disc.

This picture demonstrates the snow cloud being formed perpendicular to the rotor disc. Though this is actually a takeoff and not a landing, the pilot is using proper technique to maintain required visibility and surface references under applicable FAA regulations (FAR 91.155, 91.157, 135.205, and 135.207).

This picture demonstrates the snow cloud being formed perpendicular to the rotor disc. Though this is actually a takeoff and not a landing, the pilot is using proper technique to maintain required visibility and surface references under applicable FAA regulations (FAR 91.155, 91.157, 135.205, and 135.207).

As the approach is made, allow the aircraft to gradually slow down as you near the landing area.  Looking to the side, you will see the obscuration cloud catching up from behind as you slow. Allow the natural drag of the aircraft to be the cause of slowing, not aft cyclic. Any use of aft cyclic will quickly move rotor wash contact point, and thus the obscuration cloud, forward.

With practice it is possible to make a shallow approach to your precise landing spot without aft cyclic, resulting in a touchdown with the obscuration just reaching the mast area. One caveat is that you need to be sure of your touchdown area; this is not the time for a slope landing or to be unsure if it is a suitable landing area. The procedure is to touch down just as the groundspeed reaches zero, without ever having the rotor disc tilt aft of horizontal.

The wind can be beneficial or detrimental, so be sure to make the approach into the wind, even if just a few knots. A headwind will help keep the obscuration aft as long as possible, and help slow down the helicopter to a zero groundspeed without aft cyclic. If the wind is strong you may even be able to hover, keeping the cloud aft. If you need to slow a little quicker during the approach, use a little pedal to get out of trim and increase the drag. If I’m solo I will use the same pedal as the side I’m sitting on, to better see the obscuration cloud behind. If I have another person on board, I will use opposite pedal so that I can better see the landing area, having them watch the cloud.

For training purposes, I have flown over a snowy field at 50 feet and practiced moving the snowy obscuration cloud fore and aft, using the cyclic, but always keeping it behind. With practice you can position it and keep it exactly where you want as you make your approach. Think of it as flying two objects, the helicopter and the cloud.

The Steep Approach

This is a good technique when the area does not allow for a shallow approach, when unsure of the actual landing area, or when there is a hardpan of dirt or snow just below the loose stuff.  This technique does require more aircraft performance than the shallow approach technique, and an extended period of time hovering out of ground effect. Realistically, I do this technique about 80 percent of the time, and the shallow technique about 20 percent.

Make a slow and steep approach to your landing area, keeping the descent rate less than 300 feet per minute; settling with power considerations. Terminate to a hover, typically between 20 and 100 feet, at the first sign of an obscuration forming on the surface. The height this occurs is a good indicator of how bad the obscuration potential is. (I had a rule of thumb flying EMS at night: anything more than 75 feet was unacceptable and I would opt for another LZ.) Hold the hover as the obscuration dissipates. If there is a hardpan under the loose dirt or snow, it will get better. Adjust your altitude as necessary to remain above and clear of the obscuration. In a no-wind condition, it may take a couple of minutes for the obscuration to dissipate.

The fire truck wet down the area prior to the EMS Bell222A landing, helping mitigate the potential for a brownout.

The fire truck wet down the area prior to the EMS Bell222A landing, helping mitigate the potential for a brownout.

If the obscuration dissipates and you think it safe to land, find an object very close to your landing spot to use as a visual reference, preferably just a few feet in front of you at the 2 to 3 o’clock position (sitting right side). A rock, bush, twig will work; anything that won’t blow away. If the rotor wash unexpectedly kicks up more dirt or snow during landing, this may be your only reference to control the helicopter.

Should you ever find yourself in instrument conditions in a hover from a brownout or whiteout, you basically have two not very good options. If still high above the ground, pull max power and hopefully fly out of it without losing control, or if close to the ground lower collective and hopefully land without rolling the helicopter. Be safe and remember:  it’s better to use superior judgment, avoiding the necessity of superior skill.

(These views and opinions are my own and do not necessarily reflect the views of Era.)

CH53s landing in dusty conditions at sunset in Iraq, by pilot Dan Adams.

CH53s landing in dusty conditions at sunset in Iraq, by pilot Dan Adams.