Porterville - Porterville

The captain reported that, while returning to the departure airport following an uneventful aerial drop, he noticed that the hydraulic pressure gauge indicated 0. The first officer subsequently verified that the sight gauge for the main hydraulic fluid reservoir was empty. The flight crew began performing the emergency gear extension checklist and verified that the nosewheel landing gear was extended. The captain stated that the first officer then installed the pin in the nosewheel landing gear as part of the emergency checklist. As the flight crewmembers diverted to a nearby airport because it had a longer runway and emergency resources, they briefed the no-flap landing. The first officer extended the main landing gear using the emergency gear release, which resulted in three down-and-locked landing gear indications. Subsequently, the airplane landed normally; however, during the landing roll, the nosewheel landing gear collapsed, and the airplane then came to rest nose low. Postaccident examination of the airplane revealed that the nosewheel landing gear pin was disengaged from the nosewheel jury strut, and the pin was not located. The disengagement of the pin allowed the nosewheel landing gear to collapse on landing. It could not be determined when or how the pin became disengaged from the jury strut. Installation of the pin would have required the first officer to maneuver in a small area and install the pin while the nose landing gear door was open and the gear extended. Further, the pin had a red flag attached to it. When inserted during flight, the flag encounters a high amount of airflow that causes it to vibrate; this could have resulted in the pin becoming disengaged after it was installed. Evidence of a hydraulic fluid leak was observed around the right engine cowling drain. The right engine hydraulic pump case was found cracked, and the backup ring was partially extruded, which is consistent with hydraulic system overpressurization. The reason for the overpressurization of the hydraulic system could not be determined during postaccident examination.

Flight / Schedule

Porterville - Porterville

Registration

N4692A

MSN

726-7247

Year of Manufacture

1958

Operator

Minden Air

Date

June 15, 2014 at 08:44 PM

Type

CRASH

Flight Type

Fire fighting

Flight Phase

Landing (descent or approach)

Crash Site

Airport (less than 10 km from airport)

Crash Location

Fresno California

Region

North America • United States of America

Coordinates

36.7394°, -119.7848°

Crash Cause

Technical failure

Narrative Report

On June 15, 2014 at 08:44 PM, Porterville - Porterville experienced a crash involving Lockheed P-2 Neptune, operated by Minden Air, with the event recorded near Fresno California.

The flight was categorized as fire fighting and the reported phase was landing (descent or approach) at a airport (less than 10 km from airport) crash site.

2 people were known to be on board, 0 fatalities were recorded, 2 survivors were identified or estimated. This corresponds to an estimated fatality rate of 0.0%.

Crew on board: 2, crew fatalities: 0, passengers on board: 0, passenger fatalities: 0, other fatalities: 0.

The listed crash cause is technical failure. The captain reported that, while returning to the departure airport following an uneventful aerial drop, he noticed that the hydraulic pressure gauge indicated 0. The first officer subsequently verified that the sight gauge for the main hydraulic fluid reservoir was empty. The flight crew began performing the emergency gear extension checklist and verified that the nosewheel landing gear was extended. The captain stated that the first officer then installed the pin in the nosewheel landing gear as part of the emergency checklist. As the flight crewmembers diverted to a nearby airport because it had a longer runway and emergency resources, they briefed the no-flap landing. The first officer extended the main landing gear using the emergency gear release, which resulted in three down-and-locked landing gear indications. Subsequently, the airplane landed normally; however, during the landing roll, the nosewheel landing gear collapsed, and the airplane then came to rest nose low. Postaccident examination of the airplane revealed that the nosewheel landing gear pin was disengaged from the nosewheel jury strut, and the pin was not located. The disengagement of the pin allowed the nosewheel landing gear to collapse on landing. It could not be determined when or how the pin became disengaged from the jury strut. Installation of the pin would have required the first officer to maneuver in a small area and install the pin while the nose landing gear door was open and the gear extended. Further, the pin had a red flag attached to it. When inserted during flight, the flag encounters a high amount of airflow that causes it to vibrate; this could have resulted in the pin becoming disengaged after it was installed. Evidence of a hydraulic fluid leak was observed around the right engine cowling drain. The right engine hydraulic pump case was found cracked, and the backup ring was partially extruded, which is consistent with hydraulic system overpressurization. The reason for the overpressurization of the hydraulic system could not be determined during postaccident examination.

Aircraft reference details include registration N4692A, MSN 726-7247, year of manufacture 1958.

Geospatial coordinates for this crash are approximately 36.7394°, -119.7848°.

Fatalities

Total

0

Crew

0

Passengers

0

Other

0

Crash Summary

The captain reported that, while returning to the departure airport following an uneventful aerial drop, he noticed that the hydraulic pressure gauge indicated 0. The first officer subsequently verified that the sight gauge for the main hydraulic fluid reservoir was empty. The flight crew began performing the emergency gear extension checklist and verified that the nosewheel landing gear was extended. The captain stated that the first officer then installed the pin in the nosewheel landing gear as part of the emergency checklist. As the flight crewmembers diverted to a nearby airport because it had a longer runway and emergency resources, they briefed the no-flap landing. The first officer extended the main landing gear using the emergency gear release, which resulted in three down-and-locked landing gear indications. Subsequently, the airplane landed normally; however, during the landing roll, the nosewheel landing gear collapsed, and the airplane then came to rest nose low. Postaccident examination of the airplane revealed that the nosewheel landing gear pin was disengaged from the nosewheel jury strut, and the pin was not located. The disengagement of the pin allowed the nosewheel landing gear to collapse on landing. It could not be determined when or how the pin became disengaged from the jury strut. Installation of the pin would have required the first officer to maneuver in a small area and install the pin while the nose landing gear door was open and the gear extended. Further, the pin had a red flag attached to it. When inserted during flight, the flag encounters a high amount of airflow that causes it to vibrate; this could have resulted in the pin becoming disengaged after it was installed. Evidence of a hydraulic fluid leak was observed around the right engine cowling drain. The right engine hydraulic pump case was found cracked, and the backup ring was partially extruded, which is consistent with hydraulic system overpressurization. The reason for the overpressurization of the hydraulic system could not be determined during postaccident examination.

Cause: Technical failure

Occupants & Outcome

Crew On Board

2

Passengers On Board

0

Estimated Survivors

2

Fatality Rate

0.0%

Known people on board: 2

Operational Details

Schedule / Flight

Porterville - Porterville

Operator

Minden Air

Flight Type

Fire fighting

Flight Phase

Landing (descent or approach)

Crash Site

Airport (less than 10 km from airport)

Region / Country

North America • United States of America

Aircraft Details

Registration

N4692A

MSN

726-7247

Year of Manufacture

1958