Pinnacle Airlines Flight 3701

Pinnacle Airlines Flight 3701
Company machine of the same type as the aircraft involved in the accident
Accident summary
Accident type	Crash due to stall and flame stall
place	Jefferson City , USA
date	October 14, 2004
Fatalities	2
Survivors	0
Injured	0
Aircraft
Aircraft type	Bombardier Canadair Regional Jet CRJ200
operator	Pinnacle Airlines (now Endeavor Air) operated for Northwest Airlines
Departure airport	Bill and Hillary Clinton National Airport
Destination airport	Minneapolis-Saint Paul International Airport
Passengers	0
crew	2
Lists of aviation accidents

Pinnacle Airlines Flight 3701 was a Pinnacle Airlines flight on October 14, 2004, a Bombardier Canadair Regional Jet CRJ200 operated for Northwest Airlines crashed near Jefferson City in the US state of Missouri . The two pilots who were traveling alone on this transfer flight were killed in the attempted emergency landing . Due to the circumstances of the accident, the crew was proposed for the negative Darwin Award .

the accident

Information on the crew, aircraft and flight mission

The crew consisted of a 31-year-old captain and a 23-year-old co-pilot. The master had a total flight experience of 6,900 hours since 1995, of which 973 on the CRJ200, the co-pilot 761 hours in total since 2001, of which 222 on the CRJ200. Both were to transfer the machine, a Bombardier CL-600-2B19, marketed as the CRJ200, with the registration number N8396A, from Little Rock , Arkansas to Minneapolis . The machine had the serial number 7396 and was delivered to Pinnacle on May 18, 2000. At the time of the accident, the aircraft had completed 10,168 flight hours on 9,613 flights. The takeoff weight was 39,336 pounds, approximately 13,500 pounds less than the maximum takeoff weight, and the center of gravity was within the allowable range. The last routine maintenance work took place on October 13th and October 7th, and no discrepancies were found.

Flight history

The machine took off at 9:21 p.m. CDT from Little Rock National Airport (now Bill and Hillary Clinton National Airport ) and was cleared to climb to 33,000 feet (10,000 meters ). Shortly after take-off, the crew abruptly increased the angle of attack to 22 °, which caused an acceleration of 1.8 g and activated the stick shaker . This is intended to warn the crew of an impending stall. The maneuver was repeated two more times during the climb. In the meantime the crew members changed places, why could not be clarified.

At 9:36 p.m., the crew received the clearance to climb to 41,000 feet (12500 meters) instead of the planned 37,000 (11,280 meters), the maximum permitted altitude of the aircraft type, which, however, was not reached during normal flight operations because the aircraft was too loaded difficult for this altitude. For this reason, an air traffic controller from the Area Control Center (ACC) in Kansas had the aircraft types confirmed:

Kansas ACC: "I've never seen you guys up at forty one there."

"I've never seen you fly so high before."

Flight 3701: "We don't have any passengers on board so we decided to have a little fun and come on up here. [...] this is actually our service ceiling. "

"We don't have any passengers on board and we just wanted to have a little fun [...] that [flight level 410] is our service ceiling, by the way."

At 21:54:32, the crew saw that the aircraft's speed continued to decrease; four seconds later the stick shaker was activated again, as the aircraft was flying just above the demolition speed. At this point the speed was still 150 knots (280 km / h ) at an angle of attack of 7.5 °. At 9:54:45 p.m. and 9:54:54 p.m., the stickshaker was operated again, while the engine speed and fuel flow decreased. After the stick pusher had automatically pushed the control column forward, the pilots pulled it back again, which led to an angle of attack of 29 ° and a stall . At 21:55:06 h the master declared an air emergency , during which the crew initially succeeded in intercepting the aircraft at around 34,000 feet (10,360 meters). At this point in time, the engines had failed due to a flameout .

The controller allowed the crew to descend to 24,000 feet (7315 meters) without knowing at this point that both engines had failed. The crew started the auxiliary power plant to maintain power and began going through the engine restart checklist . This required an altitude of 13,000-21,000 feet (3960-6400 meters) and a speed of 300 knots (555 km / h) if the auxiliary power unit was not to be used. The restart was also unsuccessful because tests showed that the engine experiences a so-called core lock in the event of a sudden failure . The blades of the turbine rub against the outer casing of the engine because they expand due to the temperature differences (hot exhaust gases compared to cold ambient air). To avoid this core lock , a speed of more than 240 knots (445 km / h) is required, but this speed was not flown, the machine flew between 170 (315 km / h) and 236 knots (437 km / h) fast.

At 22:03:09, the master informed the pilot that one engine had failed and that the second engine would be restarted at 13,000 feet (3960 meters), which was approved. Four attempts to start the engines with the auxiliary unit were unsuccessful during this time. At 10:10 p.m., the controller gave the crew information about the nearest airport, Jefferson City Memorial Airport ; the crew could see the airport from 10:14 p.m. but could no longer reach it. The last sound before the impact near a road was recorded by the cockpit voice recorder at 10:15:06 p.m.

The aircraft was destroyed by the impact and a fire that broke out and the crew killed on impact. Several garages and gardens were affected, people on the ground were not harmed.

causes

The NTSB saw the cause of the aircraft accident only in the crew; problems with the aircraft or due to the weather could be ruled out. Particular emphasis was placed on the unnecessary stress on the aircraft during the climb up to the response of the stickshaker and stickpusher , the ascent on flight level 410 with the vertical speed mode , which determines a rate of climb, but gains the energy required for the climb through the speed, so that this dropped and led to the fact that the available thrust was no longer sufficient to maintain a speed above the stall speed at this altitude as well as the wrong reaction to the failure of both engines, in particular the too low speed that caused the inner shaft to seize of the engines ( core lock ) and the failure to select a suitable landing field in good time.

Trivia

Due to the circumstances, in particular that the crew had brought themselves into the threatening situation without need and then did not take the right steps to save themselves for several minutes, the two pilots were proposed for the negative prize of the Darwin Award , which "honors" people who have killed themselves through their own stupidity or carelessness.

Individual evidence

1. ↑ ^{a b} What Went Wrong: The Crash Of Flight 3701. Two joyriding pilots took a jet to its 41,000-ft. ceiling - and paid for the stunt with their lives. PM investigates the crash of Flight 3701. In: Popular Mechanics. January 4, 2006, accessed April 20, 2016 . 
2. ↑ ^{a b c d e f g} Crash of Pinnacle Airlines Flight 3701 Bombardier CL-600-2B19, N8396A Jefferson City, Missouri October 14, 2004. (PDF) In: National Transportation Safety Board . January 9, 2007, accessed on April 20, 2016 (final report of the US Aircraft Accident Authority). 
3. ↑ Mishaps - Pinnacle Airlines 3701. (No longer available online.) In: Code 7700. Archived from the original on April 20, 2016 ; accessed on April 20, 2016 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
4. ↑ 4-1-0 Club. In: Darwinawards.com. Retrieved April 20, 2016 . 

Coordinates: 38 ° 32 ′ 57 "  N , 92 ° 8 ′ 36"  W.