Accident Learjet 25C PT-LHU, Tuesday 28 July 1992
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Date:Tuesday 28 July 1992
Time:09:11
Type:Silhouette image of generic LJ25 model; specific model in this crash may look slightly different    
Learjet 25C
Owner/operator:Crasa Taxi Aéreo
Registration: PT-LHU
MSN: 25-099
Year of manufacture:1972
Total airframe hrs:5655 hours
Fatalities:Fatalities: 6 / Occupants: 6
Other fatalities:0
Aircraft damage: Destroyed, written off
Category:Accident
Location:Icapara, Iguape, SP -   Brazil
Phase: En route
Nature:Passenger
Departure airport:Curitiba-Afonso Pena International Airport, PR (CWB/SBCT)
Destination airport:Rio de Janeiro (unknown airport), RJ
Investigating agency: CENIPA
Confidence Rating: Accident investigation report completed and information captured
Narrative:
The Learjet 25C departed Curitiba at 08:50, bound for Rio de Janeiro. The aircraft climbed to the requested flight level FL330. After levelling off there was no adequate reduction in engine power. After three minutes and ten seconds the stick puller activated and the aircraft climbed to FL339. It then entered a steep descent of about 18000 feet per minute until it impacted the ground.

Contributing factors
a. Human Factor
(1). Undetermined Physiological Aspect
Given the characteristics of the accident, which resulted in the destruction of the bodies, making it impossible to carry out examinations, it cannot be specified whether it contributed or not. However one cannot rule out the possibility that one of the crew members has been affected by a sudden illness (2nd Hypothesis of the Analysis).
(2). Psychological Aspect - Undetermined
It may have influenced, to the extent that the commander was operating an aircraft in which he had little experience and little knowledge, and which was demonstrated by the insecurity in the operation, reported to other pilots.
b. Material Factor
(1). Design Deficiency - Undetermined
Despite the information provided by representatives of Learjet Corp. who participated in the investigations, that the compensator engine ("pitch trim") with which this aircraft was equipped, had already undergone the modifications determined by the Federal Aviation Administration (FAA), one cannot help but wonder about a possible firing and locking of the "pitch trim" engine in the extreme position (3rd Hypothesis of the Analysis). This aspect was hampered as the destruction suffered by the aircraft made a detailed analysis of the pitch trim system impossible.
c. Operational Factor
(1). Disabled Instruction - Contributed.
The commander and the co-pilot received a less than desired instruction, in quantitative and qualitative terms. As a result, the pilots did not acquire the full technical conditions necessary for the proper operation of the aircraft. The failure to perform the standard procedure to be followed in the emergency that led to the accident, i.e. the lowering of the landing gear, attests to the poor instruction given.
(2). Deficient Application of Controls: - Contributed
The pilots did not adjust the engine power properly after leveling and, after the aircraft started to abruptly descend, as a result, the "overspeed" occurred, they could not avoid the loss of control.
(3). Weak Cockpit Coordination - Contributed.
The pilots made inadequate use of the aircraft's resources for its operation.
(4). Forgetfulness - Contributed.
This aspect is in accordance with the previous one, since the lowering of the undercarriage is part of the standard procedure to be performed in cases of overspeed.
(5). Little Flight Experience in the Aircraft - Contributed
The captain, despite having 6,500 hours of flight time, had already intended to fly another jet plane, but had flown little on Learjet. The other pilot, in turn, had had less experience in jet flying as a co-pilot, and in the Learjet, specifically, flew less than the commander.
As a result, when they were faced with an emergency that required rapid identification in order to take the necessary measures to remedy it, they lacked the necessary experience.
(6). Deficient Supervisor - contributed.
The air taxi company, to which the pilots belonged, was in a hurry to train this new crew. This resulted in inadequate operational training for the pilots, which demonstrates poor supervision of the company.
The Civil Aviation System, through the regional body that deals directly with general aviation, failed to carry out proper oversight, as it did not detect the errors in the statements of instruction, and allowed the checks of the captain and the co-pilot to be carried out without reaching the minimum amount of flight hours and landings on that aircraft.

Accident investigation:
cover
  
Investigating agency: CENIPA
Report number: final report
Status: Investigation completed
Duration: 2 years and 12 months
Download report: Final report

Sources:

Folha de Sao Paulo 29-7-1992
Jornal do Brasil, 29 July 1992 p.8

Statistics

  • 82nd worst accident in 1992
  • 9th worst accident of this aircraft type
  • 5th worst accident of this aircraft type at the time

Location

Revision history:

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