N234ZM – Hughes OH-6A – 1998-09-25 NTSB Accident Report

HISTORY OF FLIGHT

At 1115 central daylight time (CDT), September 25, 1998, a Drug Enforcement Administration (DEA) OH-6A, registration N234ZM, manufactured by Hughes Helicopter as serial no. 59-1178, crashed about 1 mile east of Copeland Airport (airport identifier 4TA, airport elevation 688 feet mean sea level - msl), Newark, Texas. [1, reference footnotes following Narrative] The helicopter impacted on a southwesterly course onto slightly-rising ranchland about 3/4 mile from the headquarters of Kenneth Copeland Ministries. [2] The land in the area of the crash site was owned by the Texas National Guard and was used by the DEA for helicopter flight training. [3] There were two persons on board the helicopter: an instructor pilot (IP) who was an employee of Raytheon Corporation, and a transition pilot (TP). The TP was a DEA special agent/pilot on a syllabus flight as part of transition training from reciprocating engine-powered helicopters to the turbine-powered OH-6A. The DEA-owned public-use aircraft was being flown on a VFR flight plan, as an instructional flight conducted under the Code of Federal Regulations, 14 CFR Part 91. The IP sustained fatal injuries. [4] The TP escaped from the wreckage, having sustained severe burns. [5] The helicopter was destroyed. [6]

The flight departed the DEA operations facility at Alliance Airport (identifier KAFW), Texas, at 1028 CDT [7] for the practice area, about 9 miles west of KAFW . The TP received a commercial pilot "add-on" helicopter rating, September 19, 1998, following an FAA check flight in a Schweizer 300CB. [8] Prior to beginning the OH-6A transition syllabus with the IP, the TP flew two OH-6A familiarization flights with another DEA OH-6A aircraft commander. [9] The accident flight was the 5th flight in syllabus transitional training for the TP that started September 21, 1998, all with the accident IP, who was the designated DEA instructor for the OH-6A. [10]

Interviewed in hospital intensive care, the TP stated that upon arrival in the training area he flew a series of normal approaches and practice autorotations to recovery with power. [11] After the TP completed recovery from a practice autorotation, the IP complemented him on his performance. The TP acknowledged the instructor's complement, but stated that he may have to autorotate to a "50-foot area in Dallas." The TP then took control of the helicopter and said "watch this," [12] the IP initiated a turning climb to the left and about 300 feet above ground level (agl) initiated an "abrupt" maneuver, a near-90 degree left angle of bank and a "fast and steep angle of descent." The TP stated that he hoped "there would be enough at the end." [13]

The TP stated that the helicopter hit hard and the left skid broke. He "saw Larry" (the IP in the left seat) below him on the ground. The TP was able to unstrap and exit his seat and the helicopter, which was in flames. His clothing was burning, he rolled on the ground, tried to put out the flames, and two men came to him to assist and cut his clothing from him. He tried to sit and told them to "get Larry, get Larry." He asked for water.

A third man arrived, who had been driving in his pickup truck and had observed the helicopter flying level, then turn left and descend to impact. [14] He stated that when he ran to the burning helicopter, he saw the remaining pilot motionless and apparently fatally-injured. Because of the intensity of the fire, the men were not able to extract the IP. The third man to arrive then called Copeland Airport, notified them of the crash and fire, and requested that they immediately bring foam-producing fire extinguishers to the site.

Based on a 47-minute flight duration, it is estimated that the aircraft consumed approximately 18 gallons of jet fuel, at 22 gallons per hour approximate consumption. At this rate of consumption, approximately forty-four gallons of fuel is estimated to have remained in the tank at the time of impact.

The accident occurred in daylight, in visual meteorological conditions, at 33 degrees, 00 minutes north latitude, and 97 degrees, 29 minutes west longitude.

INJURIES TO PERSONS

The IP sustained fatal injuries. The TP sustained major injuries, as severe burns.

DAMAGE TO AIRCRAFT

The aircraft was destroyed by impact and post-crash fire.

PERSONNEL INFORMATION

The flightcrew was comprised of a contractor-provided (Raytheon) Instructor Pilot and a DEA Special Agent transition pilot. The IP held FAA ratings as an airline transport pilot (ATP), certified flight instructor (CFI), and certified flight instructor - instrument (CFI-I) in helicopters; and commercial pilot (COMM) single engine land (SEL), instrument (INST) and CFI in airplanes. He had a total of approximately 14,500 flight hours. Less than 200 of the total flight hours were in fixed-wing aircraft, the remainder in helicopters. The TP accumulated 1,003 total flight hours, 77.6 of which were in helicopters, the remainder in fixed wing. The TP held FAA ratings as COMM multi-engine land (MEL), and INST in airplanes and COMM in helicopters. Upon completion of an FAA examination, including a check flight in a Schweizer 300CB, the TP received a commercial pilot rating - helicopter, September 19, 1998.

THE INSTRUCTOR (IP)

The IP, age 51, had worked 6 years as a contractor-provided instructor at the DEA's Aviation Operations Center. The operations center was previously located at Addison Airport north of Dallas, then moved to Alliance Airport, north of Fort Worth, February 1994. The IP first soloed in 1965, and flew as a U.S. Army helicopter pilot in Vietnam in 1968. He subsequently held flight positions for operators in the United States and at foreign bases, including offshore oil rig, jungle "helerig" and South American and Caribbean drug eradication operations. His last Class I medical certificate was dated January 14, 1998, and included the limitations "Pilot must wear corrective lenses for near vision. NIDDM - No Meds - Hemoglobin A1C was 6.8."

FAA records showed no enforcement actions regarding the IP. There was one Accident/Incident Report, which referred to a Controlled Collision with the Ground, resulting from a main drive shaft boot failure, in a Bell 205 helicopter, occurring June 28, 1978. Also, DEA operational records showed two previous flight incidents. In the first incident, two uncommanded engine shutdowns occurred during two demonstrated hovering autorotations on the same day, in the accident helicopter, N234ZM. The report noted that both engine shutdowns occurred as the IP, seated in the left seat, rolled the throttle to idle. A possible cause was listed as "Mechanical problem." The left seat position did not have a flight-idle release. Responding maintenance actions recorded collective and engine linkage inspections and repairs. A second incident, occurred November 3, 1995. [15] Under Describe Event/Situation, the DEA Aviation Section Incident Form states, the IP "took control of the A/C and stated that he would demonstrate [a] zero airspeed auto-rotation. [He] then entered the maneuver and began explaining a proper procedure. At approx. 70' AGL [he] began to flare the A/C at which point [he] stated, "I forgot to roll the throttle in." As the A/C began to level at approx. [? feet] I noticed the torque gauge indicate past 120 [percent] at which point the maneuver was terminated [in] a hover."

TRANSITION PILOT (TP)

The TP, age 34, had served as a DEA Special Agent approximately 6 years. Previously, he had served for 2 years as a Dallas Police Officer, and for 2 1/2 years as an Officer in the U.S. Navy. During his Naval service, he received Naval Flight Instruction, including Aircraft Carrier Qualification. DEA records did show a designation as a Naval Aviator. FAA records showed no Accidents, Incidents, or Enforcement actions. His most recent medical certificate was Class II, dated February 11, 1998.

The TP graduated from a primary helicopter flight training course offered by SKY Helicopters in a Schweizer 300CB, September 19, 1998, which included qualification to be the solo pilot of that aircraft.

AIRCRAFT INFORMATION

The accident helicopter, an OH-6A, 59-1178, was manufactured by Hughes Helicopter as serial no. 59-1178, and sold to the U.S. Army in 1968. The helicopter was transferred to the DEA on September 4, 1992, and listed by the DEA as "mission capable," October 29, 1993. On September 23, 1998, the last flight prior to the accident flight, the helicopter had accumulated 4,783.3 total flight hours [16].

MAINTENANCE SUMMARY

The aircraft maintenance records noted two avionics discrepancies [17]. There were no overdue inspections, or servicing actions indicated as due in the records. FAA records revealed that N234ZM sustained accident damage, August 25, 1995, resulting from a hard landing and roll during an attempted pinnacle landing. The accident was listed as Pilot-Induced. The helicopter was repaired by Corporate Jets Aerospace, Inc., the maintenance contractor for the DEA at that time. The repair recorded replacement of basically the main and tail rotor drive systems, including the main and tail rotor gearboxes, extensive sheet metal repairs, component replacements, and a test cell run of the engine.

Records showed that the September 25, 1998, accident engine, serial no. CAE400126, had been overhauled by Corporate Jets Aeorspace, Inc., June 27, 1996, and test run by Dallas Airmotive, July 9, 1996. It was installed on N234ZM, June 4, 1998, and, at the time of the accident flight, accumulated 19.9 hours since overhaul. [18] The engine was installed as a replacement engine, in response to recurring write-ups regarding hung starts. Subsequent to its installation on the accident helicopter, there was one recorded engine-related maintenance action. It regarded engine oil pressure indications. The maintenance action, dated September 24, 1998, the day prior to the accident, was to remove and replace the oil pressure sending unit. A ground run and leak check were performed and the helicopter was then released for flight. The next scheduled engine inspection was a 25 hour inspection due in 5.1 hours.

A Special Agent/Pilot for the OH-6A told investigators that he had flown the accident helicopter with the TP, twice, on September 14, and 18, 1998, to help familiarize the TP with the OH-6A, before he entered syllabus transition training. The Special Agent/Pilot stated that he had been concerned, since flying the helicopter on September 14. He also submitted a written statement to the investigation, stating that in a practice autorotation he was demonstrating for the TP, "The aircraft was flared, forward momentum was checked, and the aircraft was leveled as it started to descend toward the ground. At this time, collective was applied in order to recover to a three foot hover. I was surprised at the engine's reaction. I perceived a delay followed by an engine surge which created a significant yaw to the right. The yaw was corrected and recovery was completed approximately two feet above the ground....I advised [the accident IP] that he should try to ascertain if there was any problem with the engine prior to conducting any autorotation training. [He] advised me that he 'would definitely take a look at it.'" [19]

In the wreckage examination, it was noted that the fuel tank was not the original Military Standard tank for the Hughes OH-6A. The records contained a Memorandum from the DEA Maintenance Supervisor to the Site Manager, Corporate Jets Aerospace, Inc., dated June 23, 1994. It stated, in part, "While these tanks are not STC'd, they have been engineered and designed to current FAA standards. As you are aware, Fargo is a reputable company, which currently builds STC'd tanks for the general aviation industry. While recognizing that the fuel tanks are not STC'd, the DEA is instructing CJAI to install the Fargo OH-6 fuel tank in selected DEA OH-6 helicopters."

Aircraft Weighing Records (weight and balance) were on file and dated August 31, 1994, and September 6, 1996. [20] No prior-to-flight weight and balance records were submitted.

METEOROLOGICAL INFORMATION

The accident occurred in visual meteorological conditions (VMC). The latest weather report for KAWF prior to the accident was at 1053 CDT / 1553 UTC:

Surface winds 210 degrees at 10 knots, visibility 5 miles in haze, temperature and dewpoint, 31 and 22 degrees Celsius, altimeter 29.99 inches of mercury. [21]

AIDS TO NAVIGATION

No problems were noted with aids to navigation.

COMMUNICATIONS

The flight was not in communication with KAFW Tower or air traffic control at the time of the accident. 4TA did not have a tower.

AIRPORT INFORMATION

At the time of the accident, the flight was operating under visual flight rules in visual meteorological conditions, about 1 mile east of 4TA.

FLIGHT RECORDERS

The aircraft was not equipped with cockpit voice or flight data recorders. None were required.

WRECKAGE AND IMPACT INFORMATION

Examination of the wreckage site, including ground scars, evidenced that the helicopter first impacted in a nose-high attitude, on a course of 230 degrees, about 50 feet northeast of the location where the main wreckage came to rest. There were two initial scars in the hard, dry soil, in the size and shape of tail rotor blade airfoil-shaped tips [22]. Continuing on the southwesterly impact course, there were three more ground scars that by size, shape, and distance apart, evidenced that they were the result of impact from the two fractured tail rotor blades. Further on the impact course, these ground scars were followed by a scar in the soil, approximately 4 inches in depth, that by shape and depth evidenced having resulted from ground impact of the tail rotor hub.

Immediately to the right of the initial tail rotor blade ground-scar, was a swipe of white paint in a small ground scar, evidencing that it was the initial location of tail "stinger" ground impact. Tail rotor blade and hub impact marks continued on initial impact course. The fractured left skid and ground scar indicated that the rear of the left skid impacted the ground about 12 feet beyond the first tail rotor blade impact. [23] Wreckage and ground scars indicated that the aircraft rolled left and then pitched nose-down following left skid impact.

Scars, impressions, and paint transfers indicated that after initial tail rotor blade impact, a main rotor blade passed down through the through the tail pylon and tail drive shaft, and main rotor blades then dug into the ground. The helicopter slid slightly to the right of impact course and came to rest on its left side, on a heading of approximately 260 degrees, to the right of an approximately 11 foot tall, bush-like tree [24]. The main wreckage was extensively burned, and a grass fire burned surrounding grass and small trees.

The aft portion of the pylon and tail rotor assembly were found about 55 feet northwest of the final resting location of the fuselage. Prior to the fuselage coming to rest, transparencies separated from the exterior of the cockpit. Near the transparencies and on the wreckage path prior to the final resting location of the fuselage were the left seat pilot's (IP's) tail rotor control pedals, and one pedal from the right seat pilot's (TP') station, as well as the lower blade from the lower wire cutter, and the left skid tube. The main gearbox, rotor head, and rotor blades lay near the edge of the main wreckage / main fire area and sustained limited fire damage. One main rotor blade lay in the main fire.

MEDICAL AND PATHELOGICAL INFORMATION

The IP sustained fatal injuries due to impact and post-impact fire injuries. The Regional Flight Surgeon, ASW-300, in a letter to the NTSB (Subject: Toxicology Report) stated, in part, "Note Dr. Canfield's comments regarding elevated Glucose levels on the 2nd page of the supplemental toxicology report." Subsequently, the Medical Officer of the NTSB provided a statement that states, in part, "It is likely that this marked elevation in blood sugar was largely a result of the extreme stress of the crash and post-crash environment. It is unlikely that the levels contributed significantly to the accident." [25]

The TP sustained severe injuries due to fire, and was moved to the Burn Unit at Parkland Hospital, Dallas.

FIRE

As noted in the TP's interview and evidenced at the site, fire erupted immediately upon impact. The intensity of the fire prevented the first persons at the site from extracting the IP. There was no fire-fighting equipment at the site. The third man to arrive at the crash site called Copeland Airport and requested foam-producing fire-fighting extinguishers, immediately. Local fire-fighting units arrived and put out remaining fire, including a large surrounding grass fire. The in-aircraft fire extinguisher was found in an exploded condition, 405 feet northeast of the fuselage final resting site.

The aircraft fuel tank was destroyed in the impact and fire. The fuel system/cells were not original to the accident helicopter, as described in the Maintenance Summary, above. The replacement fuel system provided for greater capacity. An operations representative / party coordinator stated that replacement crashworthy fuel cells were not available. [26]

SURVIVAL ASPECTS

The impact and immediate fire were not survivable for the IP, and the intensity of the fire prevented initial rescuers from access to his location in the wreckage. The TP extracted himself from the right seat and egressed with his clothing on fire.

TESTS AND RESEARCH

Under Safety Board Investigator-in-Charge (IIC) oversight, engineering disassemblies and examinations were conducted at Rolls Royce Allison, Indianapolis, Indiana, for the accident engine, and at Boeing, McDonnell Douglas Helicopter Systems, Masa, Arizona, for the main gearbox, transmission drive shaft, and overriding clutch. Engineering reports and attached photographs were provided by Rolls Royce and Boeing as Attachments 18 and 19. A 1-page memorandum was provided by the FAA representative at the examinations at Rolls Royce Allison, Attachment 20.

ORGANIZATION AND MANAGEMENT

The DEA Operations Training Officer at KAFW interviewed, once, and the Senior Pilot/Instructor Coordinator was interviewed, twice. It was not evidenced that scheduled standardization meetings were held for instructor pilots.

The basic flight operations manual was essentially copied from the U.S. Army manual. Regarding instructional techniques and student performance requirements, in, for example, autorotations, the DEA OH-6 Pilot Transition lesson plan states, "Introduce autorotations." There was no more precise writing found to describe to instructors how to introduce or students how to perform autorotations. When asked, the Training Officer stated that would be a Raytheon document. When the Chief Pilot was asked a similar question, in a second interview, he stated that there were not more precise lesson plans or instructional descriptions at the unit. [27]

ADDITIONAL INFORMATION

The following are also attached:

a. NTSB Pilot / Operator Aircraft Accident Report, Form 6120. 1/2, prepared by Operator, Attachment 23.

b. NTSB Form 6120.4: Supplements E -Second Pilot Information; F - Pilot / Second Pilot Training and Proficiency; G - Rotorcraft; I - Crash Kinematics; K - Occupant, Survival and Injury Information (for IP and TP); L- Seat, Restraint System and Fuselage Defloration (for IP and TP); M - Search / Rescue / Firefighting / Medical Treatment; N - Fire / Explosion; Attachment 24.

c. NTSB Attendance Records, and List of Disassembly and Inspections participants, Attachment 25.

_______________________

Footnotes:

[1] 1115 CDT was 1615 universal coordinated time (UTC). Regarding the time of the accident, Attachment 1 contains notes of Mr. Tim Liddle, Federal Aviation Administration, Flight Standards District Office at Alliance Airport (FAA, KAFW FISDO), regarding receipt of an "initial phone call" from Mr. Bob Johanneson (DEA); and an FAA Aircraft / Incident Preliminary Notice.

[2] Reference sketch of aircraft flight path drawn by witness Mr. Lyndon Thompson, attached to his statement (see Witness Statements), and the Tarrant County Sheriff's Department's list of First Fire Unit on scene and witnesses, Attachment 2.

[3] Reference Attachment 2.

[4] Reference from Tarrant County Medical Examiner: Cause of Death, Attachment 3.

[5] Reference Attachment 2

[6] See Wreckage and Impact Information section; and Wreckage Diagram, including photographs, Attachment 4.

[7] Reference DEA operations camera photograph of departing aircraft, Attachment 5, and portion of VFR sectional chart, Attachment 6.

[8] Reference DEA Aircraft Mission Reports, Attachment 7, and Pilot Records (TP), Attachment 8.b.

[9] Reference Memorandum of Special Agent/Pilot Stephen E. Baston, 2 pages, undated, presented during the on-site investigation; and two DEA Aircraft Mission Reports, dated September 14, and 18, 1998, Attachment 9.

[10] Reference Attachment 7, includes records of four previous syllabus flights for the IP and TP, September 21 through 23, 1998. After completion of the initial transition syllabus under a DEA IP, a TP would then be sent to a certified training base (the Boeing facility, Mesa, Arizona, was planned for advanced training for the TP). A TP would then return to the DEA facility at KAFW to begin operational flying as a copilot in model, included further training under a DEA IP, leading to a check flight for designation as pilot (aircraft commander) in model. The DEA Flight Operations Training Officer stated that check flights for a pilot rating were under a DEA supervisory instructor/check pilot, who, in the case of the OH-6A, was based in Washington, D.C., and would fly to KAFW to conduct the check.

[11] Reference summary the TP's interview in the Burn Unit, Parkland Hospital, Dallas, September 28, 1998, with the Investigator-in-Charge (IIC), Attachment 10. The summary was not signed by the TP. It was prepared following the interview as best summary, and assisted by the DEA Party Coordinator, who witnessed the interview, and FAA Party Coordinator who helped prepare the writing.

[12] The TP stated the terms "watch this" and "abrupt," initially, after being asked to describe what happened in his own words. Later in the interview, when those phrases were repeated, he stated that he had not used those words, and the IP was highly experienced.

[13] In his initial description of the event, the TP did not mention engine power during the accident autorotation. After he completed his initial description, the TP was asked some questions, including whether he recalled power coming-on during the recovery portion of the autorotation, whether he observed the needles indicating engine power during the recovery, or whether the helicopter was flared during the recovery. To each of these questions he stated that he could not remember. When asked if he followed the instructor on the controls, or noticed the twist grip coming back-on during the recovery, he stated that he was Navy-trained, and when an instructor says "I've got it," he takes his hands off of the controls. After the above questions were asked regarding the availability and application of engine power during autorotative recovery, the TP again emphasized that the instructor was highly experienced, and stated, "Make sure that you check that engine."

[14] Reference the witness statement and summary of post-statement interview of Mr. Lyndon Thompson, Attachments 2 and 10.

[15] Reference DEA Aviation Section, Incident Form, Attachment 11.

[16] Daily Aircraft Flight Log, 1 page, and Aircraft Status Report, Attachment 12.

[17] Reference Helicopter Log Book; Airworthiness Directive Records - McDonnell Douglas, and Manufacturer's Notices and Letters of Compliance Records; Raytheon Aerospace Repeat Deficiency and Recurring Discrepancy Reports; and Corporate Jets Aerospace, Inc., Customer Work Record, 1993, Attachment 13

[18] Reference Engine Log, Attachment 14

[19] Reference Attachment 9.

[20] Reference Memorandum, Subject: OH-6 Fuel Tanks, June 23, 1994; and Aircraft Weighing Records, August 31, 1994, and September 5, 1996, Attachment 15.

[21] Reference Texas A&M Weather Interface, Attachment 16.

[22] Reference Wreckage Diagram and site photographs, Attachment 4.

[23] In a static measurement of an exemplar OH-6A, 12 feet was about the distance from the rear of the left skid to the tail rotor tip path.

[24] Reference Attachment 4. There were a number of similar trees near the impact site, the tree immediately next to the location where the fuselage came to rest evidenced scars in its upper branches. When asked about trees in his interview, the TP stated that his previous power-recovery practice autorotations had been to that area, and he had not been concerned by trees. The final approach path was over slightly rising terrain, that came out of a large "dish" of land, approximately 30 feet below the impact site.

[25] Reference statement from G.J. Salazar, M.D., Regional Flight Surgeon, ASW-300; Forensic Toxicology Fatal Accident Report, from Dennis V. Canfield, Ph.D., Manager, Toxicology and Accident Research Laboratory, FAA; and Medical Analysis of Accident IAD98GA110, from Mitchell A. Garber, M.D., M.P.H., M.S.M.E, Medical Officer, NTSB; Attachment 17.

[26] Reference Attachment 15.

[27] Reference DEA Additional Commercial Rating, Helicopter, Objectives and Course Syllabus, and Helicopter Training Record and Airplane / Helicopter Training Record - Instrument sample forms, Attachment 21; and OH-6A/DOJ Pilot Transition, Objectives and Course Syllabus, Attachment 22.