Uncategorized Archive

The little helicopter that could

Thursday, September 11th, 2014

If you’ve ever flown a Mooney you know they are fast, responsive, and a great value in terms of speed for fuel. That the company has fallen and come back time and time again is as much a testament to the product as it is an indictment of the ownership.

Fly an Enstrom and look in to the company’s history and it’s clear it and Mooney are kindred spirits. The Chinese state-owned company that controls Enstrom is only the latest in a long and undulating path that includes everyone from the famous and quirky to the publicly anonymous venture capital firm. Yet, like Mooney, the products have been strong with an equally strong following. Fly one and it’s easy to see why.

The current line-up is much the same as its been for the past 10 years–the turbine 480B, and piston F-28F and 280FX. The F-28F and 280FX are essentially the same helicopter with the exception of the 280FX’s sleeker cockpit. With the infusion of money from the new owner the company has almost doubled the size of its factory and is on an ambitious plan to produce the TH180, a trainer aimed squarely at Sikorsky’s neglected S-300.

Enstrom's upcoming TH180 trainer

Enstrom’s upcoming TH180 trainer

CEO Tracy Biegler says the trainer’s certification program is a warm-up to an expanding line of products, one that probably goes up to bigger turbines. With the right strategy, and assuming the models stay true to Enstrom’s core values, they should see success.

We had the opportunity to fly both the 480B and the F-28F, both of which are quite impressive. The turbine is a bit underpowered, but it flies beautifully, and has enjoyed a great safety record. That focus on safety is part of why the company has won some important foreign military training contracts over the last five years, and what has allowed it to go from producing only five helicopters in 2012 to an anticipated 30 or so this year.

Meanwhile the turbocharged F-28F has power to spare, at least with two on board and a slightly above-standard day. We were shooting up at 1,500 feet a minute at best-climb speed. Both helicopters are rock solid to fly, have benign autorotation characteristics, and are clearly well built.

If Enstrom can stay true to its roots and the owners remain interested, the men and women of Menominee have a bright future.

Slaying the dragon

Tuesday, August 26th, 2014

Regardless of what helicopter you are flying, whether it’s the Robinson R22, Bell JetRanger, or any helicopter for that matter, you need to be comfortable with autorotations. At our flight school we have broken the auto in to three flights. If you’re a CFI reading this, try it. If you’re the student or certificated pilot looking to get proficient, ask for it.

Start with talking on the ground, sitting in the helicopter, and going through the physical motions. Move the controls the way you would actually respond. If you are the CFI, play the whole thing down (mentally) and don’t let the student get beaten before they even lift off. If you are the client/student try to put past bad experiences with autos behind you.

First Flight: Auto-rotative decent. Climb to at least 3,000 feet. I like even higher. The only thing you want at first is RPM control. There is plenty of time to adjust airspeed. RPM is the constant in most cases. Climb back up and then try adjusting the airspeed all the way through the decent from 30-70 knots, noting what cyclic control movements do to the RPMs. Get comfortable with controlling RPM with mostly cyclic movement. The ONLY thing you want to achieve by the end of this lesson is comfort with RPM and airspeed control in the decent.

Second Flight: I like to start with quick stops from 50 feet and 60 knots, which is very similar to the flare in an autorotation. End this lesson with auto-rotative descents, followed by a flare (quick stop). Join the needles (rotor and engine RPM) very early so it seems just like the two maneuvers put together. By doing this you’ve learned to join the needles at 300 feet AGL, and not in the flare where most over-speeds occur. End this lesson being comfortable with descents and the flare.

Third Flight: Go over all three maneuvers and then combine them all together. Join the needles a little further down the line each time. Don’t be crazy about that; the auto looks the same regardless of where you join the needles.

If you want to accomplish full down autorotations, add a fourth lesson of hovering autos and run-on landings, which will be the same as a touch down from zero ground speed or from 15-20 knots if you are unable to zero out the ground speed.

This should build your confidence and make it fun, regardless of what helicopter you are flying.

Robinson R22: The good, the bad, and the ugly

Tuesday, July 15th, 2014

As the President of Advanced Helicopter Concepts, Inc. in Frederick, Maryland, a Robinson Dealer and Service Center for 27 years, we have learned a lot about the Robinson R22. Advanced Helicopter currently operates five R22s, including one instrument trainer, a 1983 Alpha, serial number 378, that is still going strong.

The Good: The R22 is hands-down the world’s leader in civil helicopter training. It is like the Cessna 152 of the fixed-wing world. The helicopter is reliable, cost effective and safe if operated within its guidelines. Like it or not Frank Robinson and the R22 created an entire new helicopter market. It services the recreational helicopter pilot and allows helicopter ownership. Before the R22 and R44 both were rare. The R22 is also able to feed the rapidly growing EMS and law enforcement pilot demand that was fueled by a large crop of retiring pilots. With the demand in the last 20 years, retiring military pilots could not keep pace. With that being said…

13_Helicopter Transition_0133

The Bad: The R22 does demand respect. Regardless of your experience in the helicopter, when you think you have it figured out, it will remind you that you that it demands respect. Like all helicopters, especially those with light inertia rotor systems, the recognition time during an engine failure or other emergency requiring an autorotation is critical. The trick is to get the helicopter into an autorotation in time. Once in the autorotation it does a good job and is predictable. As a pilot of the R22 you must always be aware that getting into an autorotation is the most critical time. As a CFI you must double your effort and just know at some point in the flight you may have to take the helicopter if there is a problem. If there’s no problem, great, but the awareness must always be heightened.

The Ugly: If you are not diligent, do not get the helicopter into an autorotation in the small window, and the rotor RPM get below about 75 percent you may never get it back. So it essential to just get the helicopter into autorotation and maintain RPM, deal with airspeed, and find a suitable place next. Stored energy in altitude is your best friend; continuous low operation is not a good idea. There are other problems, such as the rapid rollover rate if you stick a skid, and the helicopter can be very unforgiving. Practice your hovering and ground maneuvers with some space between you and the ground.

Despite the issues, it is still a great helicopter and we love ours. The way the average pilot can overcome any issues is to be prepared. Visit a competent helicopter company with reputable CFIs until you have slayed the dragon and an autorotation is another day at the office.

Bell 505

Sunday, March 2nd, 2014

Heli-Expo 2014, held last week in AnaheimCalifornia, is the annual worldwide helicopter convention. At the show, Bell Helicopter announced the Bell 505 JetRanger X. The latest generation of the JetRanger series that started 50 years ago. Scheduled for its first flight later this year, the company has started signing letters of intent. The new model is aimed at a wide variety of missions, including utility, corporate, private owners and training schools.

Based on the original Bell 206B, the Bell 505 JetRanger X is a five-seat, single-engine turbine helicopter with a cruise speed of 125 knots, range of 360 nautical miles and a useful load of 1,500 pounds. The fuselage has been updated to provide a sleek modern look that features increased cabin volume and side clam shell doors. The cockpit improvements include the Garmin G1000H Integrated Avionics Suite and wrap-around windscreens providing a wide field of view. The engine has been changed to the 504 shp Turbomeca Arrius 2R engine with dual channel Full Authority Digital Engine Control (FADEC), an engine data recorder and a 3000 hour TBO. The rotor system retains the two-bladed, high inertia system that gave the JetRanger its reputation for excellent autorotation capabilities.

Bell Helicopter has also announced it will build the helicopter at a newly constructed assembly facility at the Lafayette Regional Airport in Louisiana.  Also new is a website (www.bell505.com) where customers can custom build and order the helicopter online.

505

505a

Mast moment

Monday, February 17th, 2014

A rigid (or sometimes called hinge-less) rotor system is capable of transmitting high bending forces to the main rotor shaft. When a pilot makes a cyclic movement causing the main rotor disc to tilt, the fuselage wants to follow. In flight, with a rigid rotor the mast bending moment is low. However, when the fuselage is in contact with the ground and cannot follow the main rotor disc the bending moment can be very high. 

This type of rotor system is used on the helicopters designed and built by the German manufacturer MBB (now Airbus Helicopters). Because large cyclic displacements on the ground have the potential to damage the mast assembly, a mast moment indicator (MMI) is installed. The gauge is a single dimension indicator that shows the total moment being applied to the mast. When the gauge reads high, the pilot has to figure out what direction to move the cyclic to reduce the mast moment. Over time, experience makes knowing how to keep the mast moment low a natural reaction, however, pilots new to these types of helicopters would have to be very careful not to exceed the limit. Recently, to help reduce any possible confusion a new style gauge has been developed. It is two dimensional (using a circle instead of a straight line) which makes knowing the correct direction to move the cyclic control easier. 

Normal pick-ups and set-downs require care as to not exceed the limits on the MMI. Generally, this is not difficult. However, slope landings and running landings can be more challenging. In these situations, the pilot needs to be comfortable with the MMI being close to limits and making very small cyclic adjustments. If a limit is exceeded, the amount (in percentage) and duration dictate how extensive an inspection or repair will be.

Older style MMI

Older style MMI

                   

Newer electronic single dimension MMI

Newer electronic single dimension MMI

 

 

 

 

Latest two dimension MMI

Latest two dimension MMI

Teaching autorotations

Saturday, February 1st, 2014

One of the most critical maneuvers that helicopter CFIs perform with their students is autorotations. It requires precision, timing and the ability to multitask.  Rotor RPM, airspeed and trim must all be maintained within allowed parameters while simultaneously finding a suitable landing area and maneuvering the helicopter into the wind. From 500 feet above ground level, a student has 20 to 30 seconds to process and manage all the factors and make the right decisions to achieve a successful outcome.

Allowing a student to perform an autorotation requires constant vigilance from the instructor. The best way for students to learn is by doing as much of the maneuver as possible, however, the instructor does not always have a lot of time to decide to take the controls before the student gets the helicopter in an unrecoverable situation. Sometimes, the difference between a successful practice autorotation and an accident is just a second or two.

During the first 2 months of 2012 three accidents happened from practice autorotations and the NTSB issued the following probable causes:

  • The flight instructor’s delayed remedial action during the pilot-receiving-instruction’s practice autorotation that developed a high rate of descent. Contributing to the accident was the pilot-receiving-instruction’s improper control inputs during the practice autorotation. 
  • The flight instructor’s failure to apply power during a practice autorotation in order to arrest a high rate of descent, which resulted in an in-flight collision with terrain. 

These two happened in a Robinson R22 and a R44. However, the following is from an AS350 with a more experienced instructor. 

  • The flight instructor’s improper use of the collective control during a practice hovering autorotation, which resulted in a hard landing.

Even an excellent and experienced instructor who gets distracted, even for just a second or less, can damage an aircraft. Full touchdown autorotations (that is, not bringing the engine back in before ground contact) add another level of risk. Fortunately, most accidents that happen from practice autorotations are not fatal.

 

NTSB accident references:

NTSB Identification: WPR12TA120

NTSB Identification: ERA12CA179

NTSB Identification: ERA12CA137

NTSB top 10

Sunday, January 19th, 2014

On January 16, 2014 the National Transportation Safety Board released its 2014 Most Wanted List, the top 10 advocacy and awareness priorities for the agency for the year. With the high accident rate in the helicopter industry, helicopter operations have been added to the list. According to the NTSB, between January 2003 and May 2013, 1,470 helicopter accidents have occurred, with 477 fatalities and 274 serious injuries.

The NTSB understands that helicopters are used for a range of operations, each of which presents unique challenges. For example, helicopter emergency medical services (HEMS) operators transport seriously ill patients and donor organs to emergency care facilities, often creating pressure to conduct these operations safely and quickly in various environmental conditions.  These include flying in marginal weather, at night, and landing at unfamiliar areas. Air tour operators and airborne law enforcement units face similar issues.

These and other operational issues have led to an unacceptably high number of helicopter accidents and the NTSB stated there is no simple solution for reducing helicopter accidents. However, they have recommended some safety improvements to mitigate risk. For instance, helicopter operators should develop and implement safety management systems that include sound risk management practices, particularly with regard to inspection and maintenance. Moreover, establishing best practices for both maintenance and flight personnel that include duty-time regulations that take into consideration factors like start time, workload, shift changes, circadian rhythms, adequate rest time, and other factors shown by recent research, scientific evidence, and current industry experience to affect crew alertness. Operators should also make sure that their pilots have access to training that includes scenarios such as inadvertent flight into instrument meteorological conditions and autorotation. Also noted as invaluable when an accident occurs is a crash-resistant flight recorder system that will assist investigators, regulatory agencies, and operators in identifying what went wrong and how to keep it from happening again.

Recent NTSB investigations of 3 accidents resulted in the issuance of 27 safety recommendations pertaining to issues that include risk management, pilot training, maintenance, and flight recorders.  These include a June 2009 accident near Santa Fe, New Mexico, involving a helicopter on a search and rescue mission, an August 2011 HEMS accident near Mosby, Missouri and a December 2011 air tour accident near Las Vegas, Nevada.

During the last 10 years the NTSB has issued over 100 safety recommendations. If the high helicopter accident rate continues, the FAA could step in and enact regulatory changes that would force changes on the entire industry.

 

High voltage

Thursday, January 9th, 2014

The flight characteristics of a helicopter make it suitable for a variety of interesting missions. One such job is the repair of live high voltage lines. The voltage on these lines is typically between one hundred thousand to one million volts.

A typical configuration uses a platform mounted to the helicopter’s skids with a wire attached to the helicopter’s airframe. The lineman sits on the edge of the platform as the pilot hovers the helicopter next to the line that needs repair. In some cases, the pilot must maneuver the lineman within several inches of the power line. Because this is considered an external load operation, the platform can be jettisoned. However, the lineman’s harness is attached to the helicopter.

The helicopter and the high voltage wire have different electrical potentials, so to equalize them a metal wand is brought close to the wire. When the wand is close enough the voltage jumps across causing an arc. Once the wand makes contact with the wire, a clamp is connected to the platform with a 5 or 6 foot cable that is attached to the helicopter insuring the voltage potential remains equal. The wand is then removed and the repairs can begin. In the event of an emergency the clamp will break away from the power line. The helicopter now has a high electrical potential and the pilot must be careful to not let the helicopter get to close to an object (a tree, for example) that will allow the voltage a path to ground. This will significantly increase the current flow through the helicopter causing high heat and serious damage to equipment and personnel.

Several accidents have happened from engine failures or the rotor system coming in contact with part of the power line infrastructure. One such accident happen in August of 2013 and according to the NTSB the helicopter was conducting an electrical power line construction operation with a lineman standing outside on the skid. The wire was temporarily suspended by a hoist and the lineman was inserting a fiber shoe to attach the wire to the arm of the tower. While the helicopter was hovering next to the wire at about 200 feet above ground level the hoist slipped and the wire fell onto the top of the helicopter’s skid. Control was briefly lost and four of the helicopter’s main rotor blades impacted the tower resulting in substantial damage to the main rotor blades. The pilot quickly regained control and made an emergency landing in tall corn about 200 feet from the accident location.  Fortunately, the pilot did an excellent job and no one was injured.

Even when everything goes right, high voltage power lines create a very strong electromagnetic field. This field produces an induced current that anyone close to the line will feel along their skin. As such, the pilot and lineman wear a special suit with a metal weave that allows the current to flow around the skin. Even with the suit, the sensation has been described as a feeling of pins and needles.

BK117

Monday, December 23rd, 2013

The BK117 is a twin-engine, medium size helicopter developed jointly by Messerschmitt Bolkow Blohm (MBB) of Germany and Kawasaki of Japan. In early 1977 the two companies signed an agreement to share costs and produce two prototypes each. Although development took longer than originally planned, Japanese and German authorities certified the helicopter in late 1982 followed by the United States in early 1983.

The BK117 is a compact design with a total length of 43 feet and a main rotor diameter of 36 feet. MBB used a hinge-less rotor system with four main rotor blades attached to a titanium hub. A high tail rotor and rear clamshell doors made the BK117 very popular in the EMS industry.

The first version was the BK117 A-1 powered by two Lycoming gas turbine engines. Two major problems with the A1 were the low gross weight (6280 lbs) and a lack of tail rotor thrust and stability. In 1985 MBB introduced the A3, with a larger tail rotor, an optional yaw stabilization augmentation system (YSAS) and a gross weight increase to 7,055 pounds. A year later came the A-4, with increased take-off limits and an improved tail rotor hub. All A-series BK117s use the 650 shp Lycoming LTS-101- 650B1 turbine engine de-rated to 550 shp.

In 1987 MBB introduced the B1, which used the more powerful 750 shp LTS-101- 750B1 engine (still de-rated to 550 shp) and the YSAS became standard equipment. Next was the B2, with a beefier landing gear, shorter pitch change horns to improve main rotor response time and a gross weight increase to 7,385 pounds. Also available at the same time was a C1 model with Turbomeca Arriel 1E engines rated at 708 shp for better hot and high performance.

BK117

BK117

 

 

 

 

 

 

 

 

 

In 1992, MBB and the helicopter division of Aerospatiale merged to form Eurocopter. Under the newly formed company, the BK117 underwent several upgrades including a new forward cockpit design with modern avionics. It carries the FAA designation BK117 C2, but is marketed as the EC145. Powered by a pair of Turbomeca Arriel 1E2 engines rated at 738 shp each, the gross weight jumped to 7903 lbs. In 2006, the US Army signed a contract for 345 EC145 aircraft for use as a light utility helicopter. Known as the UH 72A (Lakota), the program has been a major success for the US Army.

UH 72A Lakota

UH 72A Lakota

EC145

EC145

 

Scheduled for certification in 2014 is the EC145 T2 featuring new FADEC equipped Arriel 2E engines delivering 1039 shp each. Additional improvements include a Fenestron tail rotor, a 4-axis autopilot and a gross weight increase to 8047 lbs.

EC145 T2

EC145 T2

Volocopter

Saturday, December 7th, 2013

Over the years there have been many different inventors and engineers who have attempted to built vertical lift aircraft. The single main rotor with a smaller anti-torque rotor emerged as the most popular. With recent advances in technology, innovative engineers have been attempting to build a practical electric-powered helicopter. As it turns out, the single main rotor design is not the most efficient – efficiency is necessary for an electric-powered helicopter to be capable of lifting a reasonable payload. As such, engineers are designing very different vertical lift vehicles. One of these is the 2-person Volocopter and its first successful flight was November 17, 2013.

Designed and built in Germany, the Volocopter has an especially unique design. It uses 18 rotors, each powered by its own electric motor. They are mounted on a light weight carbon fiber ring above the cabin. Several on-board computers monitor and control the speed of each rotor system to achieve directional control – eliminating the need for any type of mechanical linkage. The system is designed so that if one of the motors fails (actually, several can fail at the same time) the aircraft can still safely land. Additionally, there is a ballistic parachute system for added safety.

Currently, the biggest limitation is battery life. The battery allows a flight time of 20 minutes, however, the company believes that advances in battery technology will extend the flight time in the near future. As an interim solution, the Volocopter will be built as a hybrid which will allow several hours of flight time. This is achieved by using a combustion engine to power a generator that supplies the batteries and motors with electricity.

The manufacturer, E-volo, claims the production aircraft will be extremely cost effective to operate, very quiet and easy to fly. More information can be found on their website: www.e-volo.com.

vc200_first-flight_13

vc200_first-flight_04