Wednesday, December 12, 2018

Event Review - Case Study: Loss of Control Due to Retreating Blade Stall

Image courtesy Australian Transport Safety Board

About 10 years ago, I corresponded with my chief pilot at Omniflight Helicopters, Mr. Eric Pangburn, about the aircraft at my base "surging" nose-up in cruise flight. It was not a violent pitch up, rather it was a smooth and steady pitch up that was overcome with a reduction of collective and forward cyclic. It was disconcerting and I wanted to know why it was happening.

The phenomenon was also experienced by another pilot at my base, Mr. Tim Lilley. Our experiences were similar and in the same aircraft, N171MU a BK-117A4. These events occurred at altitudes below three thousand feet MSL and between 60 and 90 degrees F.

Eric included his friend Shawn Coyle, a well-known helicopter expert, and writer, in our discussion, and Mr. Coyle added his thoughts - to wit that erosion of the leading edge of blades might reduce the margin to RBS. The answer: ease up and slow down.

A pilot-friend at another base, Mr. Mike Sharp (now deceased) had experienced an RBS loss of control event prior to our events. Mike was operating a BK-117A4 N117LS. His LOC was extremely violent and was similar to the event described in the linked report from the Australian Transport Safety Board. First a pitch up to near vertical, then a flopping over to a dive straight down. The medical crew became weightless in flight and came out of their seats. (Mr. Don Lamb and Mrs. Robbin Perry)

I recommend you imagine yourselves in this crews seats as you read this report. Imagine the dismay they must have felt and consider their responses, determine if you would respond in the same way or would do something differently. Mentally rehearse, prepare, and if possible prevent - this crew missed dying by a relatively small margin. The next crew might not be so lucky...

I have absolutely no scientific data to back up this assumption, but I imagine that a BK117, EC-135, or EC-145 might be similarly susceptible to this problem because of their rotor systems. If you have experience with RBS, please share what you have learned in a comment.

Safe Flights,

Dan Foulds

"Shortly after 1400 Central Daylight-saving Time, a ‘violent’, uncommanded nose-up pitching of the helicopter occurred. The pilot instinctively applied full forward cyclic control, but using both hands given the severity of the pitch-up, in an attempt to regain control but was unable to arrest the continuing nose-up pitch. At about 70° nose-up the helicopter rolled left through approximately 120° and commenced a steep descent. On seeing the ground through the windscreen, the pilot applied full rearward cyclic, which resulted in the helicopter pulling out of its now near vertical nose-down attitude and levelling off at about 1,000 ft (about 800 ft above ground level)."

Click here to access the Australian Transport Safety Board report.

Friday, November 9, 2018

Preliminary Report: Air Methods - Wisconsin - Crash Occurred April 2018. Final Report Pending. Flight Recording Device Onboard...

PHOTO: Three people were killed in a helicopter crash near Hazelhurst, Wis., officials said, April 26, 2018.
Image courtesy WSAW
Text courtesy NTSB...

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

National Transportation Safety Board
Aviation Accident Preliminary Report
Location: Hazelhurst, WI Accident Number: CEN18FA149
Date & Time: 04/26/2018, 2250 CDT Registration: N127LN
Aircraft: EUROCOPTER AS 350 B2 Injuries: 3 Fatal

Flight Conducted Under: Part 91: General Aviation - Positioning

On April 26, 2018, about 2250 central daylight time, a Eurocopter AS 350 B2 helicopter,
N127LN, impacted trees and terrain during cruise flight near Hazelhurst, Wisconsin. The pilot
and two crewmembers were fatally injured. The helicopter was destroyed during the impact.

The helicopter was registered to and operated by Air Methods Corporation as a Title 14 Code of
Federal Regulations Part 91 repositioning flight. Night visual meteorological conditions were
reported in the area about the time of the accident, and the flight was operating on a company
visual flight rules flight plan. The flight originated from the Dane County Regional Airport-
Truax Field (MSN), near Madison, Wisconsin, about 2104 and was destined for the Howard
Young Medical Center Heliport (60WI), near Woodruff, Wisconsin.

Earlier in the day the emergency medical services (EMS) crew had transported a patient to the
Madison area. The purpose of this flight was to reposition the helicopter back to 60WI. The
helicopter was serviced with 80 gallons of fuel at MSN. According to initial information, the
pilot radioed that he departed from MSN. The helicopter did not arrive at its destination at its
estimated arrival time, and the operator started their search procedures for the helicopter. The
Air Force Rescue Coordination Center placed a call to the operator and advised that an
emergency locator transmitter signal associated with the helicopter was received by the center.

The center informed the operator of a latitude and longitude in which to look for the helicopter.
The helicopter was subsequently found near that location about 0215 on April 27, 2018.

The 34-year-old pilot held a Federal Aviation Administration (FAA) commercial pilot
certificate with rotorcraft-helicopter and instrument helicopter ratings. He also held a private
pilot certificate with an airplane single engine land rating. He held an FAA second class
medical certificate issued on May 31, 2017. On his last application for the medical certificate
the pilot reported having accumulated 3,200 hours of total flight time, with 100 hours logged
with the preceding six months. According to initial information from the operator, the pilot
received training on January 5 and 7, 2018 and satisfactorily passed a check ride.

N127LN was a 2006 model Eurocopter (Airbus) AS 350 B2, four-place, single-engine
helicopter, with serial number 4149. The helicopter was configured for EMS transport services.
It was powered by a Turbomeca Arriel 1D1 turboshaft engine, with serial number 19129. The
engine had a maximum takeoff power rating of 732 shaft horsepower and a continuous power

Page 2 of 4 CEN18FA149

rating of 625 horsepower. According to initial information, the helicopter was maintained
under a company aircraft inspection program and had undergone 100 and 600-hour
inspections on April 25, 2018, at an airframe total time of 5,152.8 hours. The helicopter was not
equipped with a vehicle engine multifunction display or a digital electronic control unit.
However, it was equipped with an enhanced ground proximity warning system (EGPWS).

At 2255, the recorded weather at the Lakeland Airport/Noble F. Lee Memorial Field, near
Minocqua, Wisconsin, was: Wind calm; visibility 10 statute miles; sky condition clear;
temperature 0° C; dew point -1° C; altimeter 29.88 inches of mercury.
At 2253, the recorded weather at the Rhinelander-Oneida County Airport, near Rhinelander,
Wisconsin, was: Wind calm; visibility 10 statute miles; sky condition clear; temperature 2° C;
dew point 1° C; altimeter 29.87 inches of mercury.
At 2253, the recorded weather at the Eagle River Union Airport, near Eagle River, Wisconsin,
was: Wind calm; visibility 10 statute miles; sky condition clear; temperature 0° C; dew point 0°
C; altimeter 29.86 inches of mercury.
According to U.S. Naval Observatory Sun and Moon Data, the end of local civil twilight in the
Rhinelander, Wisconsin, area was 2031 and local moonset was at 0507 on April 27, 2018. The
observatory characterized the phase of the moon as "waxing gibbous with 88% of the Moon's
visible disk illuminated."

The helicopter was found in a wooded area about 178° and 8.4 nautical miles from 60WI. First
responders indicated that the sky was clear, the moon was visible, and there was a smell of fuel
at the time the helicopter was located. However, the wreckage did not exhibit any signs of fire.
A tree about 70 ft tall about 66° and 47 feet from the nose of the wreckage had branches broken
in its upper canopy. Trees in between this tree and the wreckage had their trunks and branches
broken and linearly separated. The path of the broken and separated trunks and branches
through the trees was steep. A ground impression about 11 ft by 9 ft and 2 ft deep was found in
front of the helicopter wreckage. The helicopter came to rest on its right side. The heading of
the wreckage from tail to nose was about 095°.

During the on-scene examination, the smell of
fuel was present at the site and in the ground below the helicopter. All major components of
the helicopter were located at the site. The cockpit and cabin area was destroyed. The fuselage
exhibited rearward crushing deformation. The tailboom was attached to the fuselage. The tail
rotor gear box and tail rotor blades remained on the tail. However, the vertical fin had partially
detached from the end of the tailboom. Both horizontal stabilizers were present on the tail. All
three rotor blades remained attached to the rotor hub, and the rotor hub was attached to the
transmission. The main rotor blades exhibited damage to include spar fractures and leadingedge
abrasions and depressions.

The main rotor hub rotated when the transmission's input drive shaft was rotated by hand. The fuel tank was fragmented. Yaw, pitch, lateral, and collective controls were traced from the cockpit to their respective servo actuators.

Engine controls were traced from the cockpit through their respective bellcranks to their engine
components. A magnetic plug in the hydraulic system had some particulate on its magnetic
end. The filter bypass button on the hydraulic control block was popped. The hydraulic pump
was turned by a drill and the pump exhibited a suction and pressure at the pump's inlet and
outlet. Disassembly of the hydraulic pump revealed scoring witness marks on the pump

Page 3 of 4 CEN18FA149

housing in its gear's plane of rotation and no debris or obstructions were observed within the
pump ports.
The engine was found on the ground and was separated from the fuselage. The engine's
compressor blades exhibited nick and gouge damage consistent with foreign object ingestion.
The power turbine blades exhibited silver colored deposits on them. The power turbine was
turned by hand and the drive train did not turn. Subsequent examination revealed that the
engine's Module 5 reduction gearbox had migrated out of its installed position, rearward, to the
extent its O-ring groove was visible. The Module 5 gearbox was removed for inspection of the
input pinion torque alignment marks. The marks were found to be misaligned approximately 2
millimeters in the tightening direction which is consistent with engine power being delivered to
the drive train during the main rotor blade impact sequence.

The Oneida County Coroner was asked to perform an autopsy on the pilot and to take
toxicological samples.

The helicopter was equipped with an Appareo Vision 1000 recorder unit, which records to both
a removable secure data (SD) card and internal memory. Both the unit and the SD card
sustained impact damage. The unit and its SD card were shipped to the National
Transportation Safety Board Recorder Laboratory to see if they contain data in reference to the
accident flight. (emphasis added)

A hydraulic fluid sample and a fuel sample were retained for testing.
Additionally, the hydraulic magnetic plug, the hydraulic pump, hydraulic filter, four actuators,
and the EGPWS were retained for further examination.
Aircraft and Owner/Operator Information
Aircraft Make: EUROCOPTER Registration: N127LN
Model/Series: AS 350 B2 NO SERIES Aircraft Category: Helicopter
Amateur Built: No
Operator: AIR METHODS CORP Operating Certificate(s)
On-demand Air Taxi (135)
Operator Does Business As: Operator Designator Code: QMLA
Page 4 of 4 CEN18FA149

Editor's note: These guys were just.like.us. What happened to them could happen to us. Let us never forget these good souls. Let us keep their families - who will suffer for this until the end of their days - in our hearts.  And let us resolve to learn from this tragedy in order to prevent something like this from happening again.


It will.

Rico CarusoKlint MitchellGreg Rosenthal.

Tuesday, September 25, 2018

It’s Time to Check the Checklist! By Josh Henke, Flight Nurse

Checklists and standardization have saved countless lives. But
"collective mindfulness" requires us to think beyond the list.

I think we can all agree that the checklist has revolutionized our industry both in commercial aviation, military aviation and HEMS. Gone are the days of going through checks thinking you put all the A tabs into the B slots and taking off by memory. And hopefully gone are the days of realizing at 500 feet of altittude that you forgot to put tab A123 into slot B 420 and returning rapidly to the earth.

Yes, checklists are good.
But they can also be bad.
Yup, I said it. Blasphemy……

Yes, checklists can be bad.
We have likely seen it or been a part of it - I know I have. We all climb in the aircraft and run through the checklist and everything is the same as the day before.

“Chocks, covers, cords?


“Engine mode switches?

“In flight”

“Caution and warning lights”

“All out”

“Doors and belts?

“Secure left, right, etc.”

We say the same things every flight. And we get into a routine. We all do it. You are not immune, I am not immune, Chuck Yeager is not immune.

Complacency is unavoidable. It is a problem that is NEVER solved, but constantly managed. The key to coping with complacency is learning how to have a functional relationship with it, knowing what it looks like and how to call it out on the carpet when it’s identified.

The checklist can be a great tool, but we need to check on it every now and then. It would be foolish to put a checklist in place, dust off our hands and say, “OK, the checklist is in place, now just follow it every time and we will be just fine.”

The checklist is a link to our survival and safety, but you can’t just put one in place and ignore it hoping that it is functioning appropriately. You need to monitor it. In short, just like everything else, you have got to check the oil and make sure it's functioning properly.

In the checklist above, can you see the problem?
Better yet, can you NOT see the problem?

In that checklist, we can lay eyes on every part of what we are covering just before lifting, except for the covers and chocks.

The point I’m trying to make is, just because you have a checklist doesn't mean that everything is OK. It needs to be evaluated and re-vamped from time to time. You need to seek out the faults in your checklist and bring them to light.

In our particular checklist, there is one item that we can’t visually inspect at the time the checklist is being performed. This leaves us prone to error. I have suggested a change of operation for my program to mitigate this.

I suggest that each of you take a look at your checklists and try to find a hole. Find something that isn’t quite right and fix it.

Go……go check the oil. Make sure everything is working the way it should be. Be a stickler about perfect function.

GO……..think outside of the box, look at things critically and make tomorrow just a little safer.

We save lives for a living. Let's save our own while we are at it.

Sunday, September 9, 2018

NTSB Final Report : North Memorial Air Care Crash

The pilot and two medical crewmembers were conducting a night instrument flight rules cross-country flight to pick up a patient. During the instrument approach to the destination airport, the weather conditions deteriorated. The pilot was using the helicopter's autopilot to fly the GPS approach to the airport, and the pilot and the medical crew reported normal helicopter operations. Upon reaching the GPS approach minimum descent altitude, the pilot was unable to see the airport and executed a go-around. The pilot reported that, after initiating the go-around, he attempted to counteract, with right cyclic input, an uncommanded sharp left 45° bank . Recorded flight data revealed that the helicopter climbed and made a progressive right bank that reached 50°. The helicopter descended as the right bank continued, and the airspeed increased until the helicopter impacted treetops. The helicopter then impacted terrain on it's right side and came to rest near a group of trees.

Postaccident examinations of the helicopter and flight control systems did not reveal any malfunctions or anomalies that would have precluded normal operation. The helicopter was equipped with a GPS roll steering modification that featured a switch that allowed the pilot to manually select the heading reference source. In case of a malfunction or an erroneous setting, the helicopter's automatic flight control system had at least two limiters in place to prevent excessive roll commands. Further testing revealed that the GPS roll steering modification could not compromise the flight director and autopilot functionalities to the point of upsetting the helicopter attitudes or moving beyond the systems limiters.

Recorded helicopter, engine, and flight track data were analyzed and used to conduct flight simulations. The simulations revealed that the helicopter was operated within the prescribed limits; no evidence of an uncommanded 45° left bank was found. The helicopter performed a constant right climbing turn with decreasing airspeed followed by a progressive right bank with the airspeed and descent rate increasing. In order to recover, the simulations required large collective inputs and a steep right bank; such maneuvers are difficult when performed in night conditions with no visual references, although less demanding in day conditions with clear visual references. The data are indicative of a descending accelerated spiral, likely precipitated by the pilot inputting excessive right cyclic control during the missed approach go-around maneuver, which resulted in a loss of control.

Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot's excessive cyclic input during a missed approach maneuver in night instrument meteorological conditions, which resulted in a loss of control and spiraling descent into terrain.

Good Souls...

Sunday, June 17, 2018

...The Journey to High Reliability

While attending a recent Promedica Health Safety Conference to present a class on hazardous attitudes, I was able to take in a presentation by Dr. Kate Kellogg (MedStar, Washington DC) on "High-Reliability Organizations."

Jonathan Godfrey, Randy Mains, and Dan Foulds
presenting AMRM topics and learning about
High-Reliability Organizations from
Dr. Kate Kellogg, MD

At AMTC, I heard Dr. Ira Blumen state that, regarding risk to patients flown in EMS helicopters, "the real risk starts when they are unloaded from the helicopter and wheeled into the hospital." Hospitals have come under scrutiny for causing harm to patients, and some of them have looked for ways to stop doing this.

Many hospitals and health-care systems have made great strides in improving patient care and reducing incidents of harm by adopting the tenets of (Air) Crew Resource Management, and then developing them further. HRO research started with the Nuclear Navy, management of the power-grid (nuclear), and air traffic control. Instead of focusing on industries and companies that went wrong (Three Mile Island) three UCB researchers concentrated on complex industries that did things right - successfully!

This video is long, and you may not get through it all in one sitting, but I encourage you to get a cold drink, and a note-pad and capture the key ideas and techniques that Dr. Mark covers.

If we want to eliminate fatal crashes in HEMS, it's apparent that we are going to have to do something different. What we are doing now doesn't work. We kill patients and crews regularly.

When you think about fatal crashes in HEMS, the only acceptable number is ZERO.

PS. Feel free to share this with your company's C.E.O; because that's where your company's journey to High Reliability will have to start...

Tuesday, May 29, 2018

My Engine Just Quit! NOW WHAT? Pilot Professional Development Courtesy of the AOPA Air Safety Institute

British warbird pilot, Mark Levy, was part of a 21-airplane formation in the annual airshow at Duxford, England when the P-51 he was flying had a partial engine out. Levy recorded the entire event on a pair of point-of-view video cameras, and he shared the images, as well as his lessons learned, in a candid discussion with Richard McSpadden, Executive Director of the AOPA Air Safety Institute.

We recommend you gather a notepad and pen and catch the key words and phrases that Mark mentions as he discusses his mishap. This is an excellent foray into pilot-psychology, how emergencies affect our physiology, when to act instinctively and when to take a deep breath and think things through. Mark repeatedly mentions "startle effect" which is a hot topic with the FAA right now.

One of the greatest pilot-learning resources is "hangar flying" with other pilots, but a HEMS pilot has little opportunity to do this. This video is a great hangar-flying experience, and might just save your life someday. Kudos and thanks to AOPA and the Air Safety Institute...