# NTSB LAX07FA012: Piper PA-42, N121CS, Prescott, AZ, October 18, 2006 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: October 18, 2006, 13:47 local (20:47 UTC) - Place: Prescott, AZ - Coordinates: 34.880279, -112.253334 - Nearby events: https://openairdocs.org/map.md?lat=34.8803&lon=-112.2533&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 5 fatal - Status: Completed, report September 27, 2007 - Report: Approved by Office Director - Parties: WP-FSDO-Scottsdale, AZ, New Piper Aircraft - NTSB case key (mKey): 64728 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX07FA012 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64728/pdf - Page: https://openairdocs.org/ntsb/LAX07FA012 ## Probable cause The failure of the pilot following a jet aircraft to maintain adequate separation from the high velocity jet core exhaust. The separation of the T-tail upper section vertical stabilizer of the following aircraft due to contact with the high velocity jet core exhaust was a factor. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - clearance - inadequate, pilot in command (cause) - vertical stabilizer - failure,total (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The pilot of a MiG 21 and the pilot of a Piper PA-42 Cheyenne III met just prior to the flight to discuss the flight in which the Cheyenne pilot would be taking aerial photos of the MiG. The two pilots established a minimum altitude of 2,500 to 3,000 feet agl and 200 knots as their minimum airspeed. The pilots did not establish a minimum separation distance, as it was not intended to be a formation flight. The MiG pilot reported that after takeoff the aircraft experienced a problem with the landing gear retraction. The pilot recycled the landing gear and a successful gear retraction was indicated. The MiG pilot notified the Cheyenne pilot of the situation and the Cheyenne pilot indicated that they would join up with the MiG, look it over and check-out the landing gear, and let the MiG pilot know what they saw. The MiG pilot flew at 9,000 feet msl in a 30-degree right hand turn at 200 knots (about 90 percent power set) with approach flaps selected (approximately 25 degrees) until the Cheyenne met up with the MiG. The MiG pilot reported that he observed the Cheyenne meet up with him at his 5 o'clock position about 300-400 feet behind him and about the same altitude. In this position, the Cheyenne was in the direct path of the high velocity jet core exhaust from the MiG. The MiG pilot looked forward and when he looked back, he could not see the Cheyenne. The Cheyenne pilot then contacted the MiG pilot and made a comment about the right landing gear or gear door, but the statement was not completed. The MiG pilot did not hear back from the Cheyenne pilot. The MiG pilot then observed smoke rising from the desert terrain and notified air traffic control. The airport manager that was monitoring the conversation between the two aircraft stated that he heard the Cheyenne pilot indicate that he would "drop down and go underneath and let you know how it looks." Wreckage documentation noted that the main wreckage was located in an inverted position on flat terrain. The T-tail, which consisted of the upper half of the vertical stabilizer, horizontal stabilizer, and elevator had separated in flight and was located about 1/2 mile south of the main wreckage. Inspection of the upper portion of the aft vertical spar displayed a right bend and twist at the point of separation. No evidence of pre-existing cracks, corrosion or wear was noted to the material. Inspection of the MiG aircraft found no evidence of contact between the two aircraft. ## Factual narrative HISTORY OF FLIGHT On October 18, 2006, at 1347 mountain standard time, a Piper PA-42 (Cheyenne III), N121CS, was destroyed when its tail section separated in flight while maneuvering about 16 nautical miles northeast of Prescott, Arizona. The airline transport pilot and four passengers sustained fatal injuries and the airplane was destroyed by impact damage and post-crash fire. The airplane was registered to Flying Moose LLC and operated by the pilot under the provisions of 14 CFR Part 91 as an aerial photography flight. Visual meteorological conditions prevailed and a flight plan was not filed for the local flight that departed the Ernest A. Love Field, Prescott, about 15 minutes before the accident. The intent of the flight was to take aerial photographs of a MiG 21 airplane (N21UT). The pilot of the MiG 21 indicated that he and the Cheyenne pilot discussed the photo flight the day of the accident, and had established 2,500 to 3,000 feet above ground level (agl) as their minimum altitude and 200 knots as their minimum airspeed. The MiG and Cheyenne pilot did not establish a minimum separation distance, as it was not intended to be a formation flight. The MiG pilot reported that they intended on adjusting the in-flight separation as the flight progressed. The MiG pilot reported that he departed the Prescott airport and flew straight out on a northeast heading. On departure, he experienced a problem retracting the landing gear and noted that only the nose landing gear successfully retracted. He recycled the landing gear handle from up to off and back to the up position, and received a successful gear retraction indication. He notified the Cheyenne pilot of the landing gear problem, but informed him that he believed the landing gear was retracted. The Cheyenne pilot indicated that they would join up with the MiG, look it over and check-out the landing gear, and let the MiG pilot know what they saw. The MiG pilot flew the airplane at 9,000 feet mean sea level (msl) in a 30-degree right-hand turn at 200 knots (about 90 percent power set) with approach flaps selected (approximately 25 degrees). He continued to circle in that configuration to allow the Cheyenne to rendezvous with the MiG. The MiG pilot reported that he observed the Cheyenne meet up at his 5 o'clock position about 300-400 feet behind him and about the same altitude. The MiG pilot looked forward and when he looked back to the Cheyenne, he could not see it. About 30 seconds later, he heard the Cheyenne pilot comment about the right landing gear or gear door, but the statement was not completed. The MiG pilot waited to hear back from the Cheyenne pilot, but when he did not receive any additional information, he asked the Cheyenne pilot to repeat because he did not understand the last transmission. The Cheyenne pilot did not respond and the MiG pilot never received additional information. The MiG pilot continued flying in that manner and tried to reach the Cheyenne pilot over the radio. After a couple of minutes he observed a column of smoke rising from the desert terrain and became concerned about the Cheyenne. The MiG pilot called the Prescott air traffic controller and asked if they were receiving an emergency locator transmitter (ELT) because he could not see the Cheyenne; could not reach him over the radio, and could now see a column of smoke in the area in which they were flying. The controller reported that they were not receiving an ELT signal but asked for global positioning system (GPS) coordinates for the smoke so they could send someone to check it out. The MiG pilot provided the coordinates and flew around a while longer to burn off fuel prior to landing. He informed the controller that he was having problems with his landing gear so the controller cleared him for the option. The MiG pilot subsequently landed uneventfully. The passenger (a non-pilot) in the MiG indicated that she heard the MiG pilot state to the Cheyenne pilot to "go ahead and fly under the airplane and check." A statement provided by the Prescott airport manager indicated that he observed the Cheyenne pilot and the MiG pilot discussing the upcoming photo flight. The MiG was to form up with the Cheyenne and make passes at the right side of the Cheyenne where the cameras would be located shooting out the open right side window. The airport manager also stated that he observed the Cheyenne takeoff and noted that the right side window had been removed. The airport manager stated that he was listening to both aircraft as they taxied and departed the airport. He then switched frequencies to the air-to-air frequency used by the MiG and Cheyenne pilot (123.45 Mhz). He reported hearing the conversation between the MiG and the Cheyenne pilots, and then heard the Cheyenne pilot indicate that he would "drop down and go underneath and let you know how it looks" after the MiG pilot informed him that he had recycled his landing gear and believed they were retracted. PERSONNEL INFORMATION The pilot of the Cheyenne held an airline transport pilot and commercial pilot certificates and was rated in the multi-engine land, single-engine land and sea aircraft. The pilot held type ratings in the Cessna CE-500, DC-3 and authorized experimental aircraft: N-T28. The pilot's flight logbook indicated approximately 4,363 hours of flight time in all aircraft, with 4,088 hours as pilot-in-command. A class I Federal Aviation Administration medical certificate was issued on September 1, 2006. No waivers or limitations were noted. AIRCRAFT INFORMATION The accident aircraft was manufactured by the Piper Aircraft Company in 1981, as a PA-42, Cheyenne III. The airframe primary structure is of all metal construction. The fuselage is an all metal, semi-monocoque structure with riveted skins. The airframe consists of three basic units: the nose section, the pressurized cabin section, and the tail section. The Piper Aircraft Pilot Operating Handbook, Description & Operation section describes the empennage as, "The empennage is a T-tail design consisting of a vertical stabilizer (fin), a rudder, a horizontal stabilizer and elevators. The rudder and left elevator each have trim tabs which are controlled from the cockpit. The right elevator has an anti-servo tab to provide pitch control forces. The empennage group components are metal cantilever structures with removable composite tips. Both the vertical and horizontal stabilizers incorporate two full span main spars." The MiG 21 UM, was manufactured by Mikoyan Gurevich in 1974 as a fixed wing, single-engine turbo-jet. The turbo-jet is a Tumansky model R-11F-300 which is located in the tail section and emits a high velocity exhaust gas from the aft end. The aircraft is operated under an experimental classification and exhibition category. WRECKAGE AND IMPACT INFORMATION The Cheyenne's main wreckage (which included the entire aircraft with the exception of the upper half of the vertical stabilizer, horizontal stabilizer, and elevator) was located at a global positioning system (GPS) measured location of 34 degrees 52.821 minutes north latitude and 112 degrees 15.197 minutes west longitude at a terrain elevation of 4,366 feet msl. The main wreckage came to rest on a heading of 230 degrees, in an inverted position, and had sustained fire damage throughout its entirety with the exception of the aft empennage, lower vertical stabilizer, and rudder. The fuselage and wing skin had melted allowing investigators to trace the control cables from the cockpit to the ailerons, rudder, and base of the elevator pushrod. No anomalies with the cables were noted. In addition, the engine controls were traced from the cockpit to their respective engines. Evidence of both wings flight control surfaces were noted in their respective positions. The T-tail section of the airplane came to rest at a GPS measured location ## Aircraft - Registration: [N121CS](https://openairdocs.org/deregistered/N121CS-2007-01-05), registration cancelled 2007-01-05, S/N 42-8001032, built 1981 (OpenAirDocs) - Reported make and model: Piper PA-42 - Registry model: [Piper PA-42](https://openairdocs.org/model/piper-pa-42) (registry code 7104202) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 42-8001032 - Airframe hours: 5317.9 - Engines: Pratt & Whitney Canada PT-6A turbo prop - Damage: Destroyed - Fire: On-Ground - Flight: Personal, Part 91 - Operator: William Friedman - Registered owner: Flying Moose LLC - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, May 1, 2006 - Departed: PRC, Prescott, AZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: fatal; commercial, airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1; seat: left; toxicology performed; flight hours: 4,363 total, 4,088 as pilot in command, 85 in the last 90 days, 7 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 18 °F - Altimeter: 30.07 inHg - Observed at: PRC, 16 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20061018029639A](https://openairdocs.org/incident/20061018029639A), Oct 18, 2006: Piper PA42, Prescott, AZ, Destroyed, 5 fatal. (-23) The aircraft was involved in an attempt to photograph a russian MIG-21 in flight 16 miles NE of Prescott AZ. Before the attempt was made the MIG-21… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.