Aero Commander 690 N15VZ

Summary

On 15 October 1996 at about 10:00 local time, a Aero Commander 690 registered N15VZ, operated by Sun West Aviation, was involved in an accident near Phoenix, Arizona, United States. 4 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

15 October 1996 at 10:00

Classification

Accident

Location

Phoenix, Arizona, United States

Nearest airport

Phoenix Sky Harbor (PHX)

Coordinates

33.4295, -112.0109

Aircraft

Aero Commander 690

Registration

N15VZ

Category

Airplane

Engines

2

Operator

Sun West Aviation

Operating rule

Part 135: Air Taxi & Commuter

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Show Low → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

LAX97LA019

Nobody was injured.

failure of the main landing gear to fully engage in the down-and-locked position for undetermined reason(s). Loss of hydraulic pressure to the main gear for undetermined reasons(s) was a related factor.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot reported that during flight, the nose gear dropped from the wheel well, he noted the hydraulic pressure had dropped to 600 psi, & the landing gear in-transit light illuminated. He said he accomplished emergency procedures, but was unable get the main landing gear to lock in the down position. The main landing gear collapsed during touchdown, & the belly of the airplane was damaged. The brake & landing gear systems were powered by 2 engine driven pumps (1 on each engine) & an auxillary (electrical) pump. For backup operation, gas pressure from an emergency nitrogen storage cylinder was continuously provided to a 2nd set of main gear actuators to provide pressure for main gear extension. During gear retraction, nitrogen was compressed back into the nitrogen cylinder. During extension, hydraulic pressure & nitrogen pressure work together to extend the main gear. After the accident, a hydraulic fluid leak was found at a hydraulic line fitting on the right main landing gear brake system, but no other leak was found. The leak was repaired, & the landing gear was functionally checked; the retraction & extension cycle functioned normally, & no system fault was found. No reason was found to explain why gas pressure from the emergency nitrogen storage cylinder did not lock the main gear in the down position.

Quoted verbatim from the NTSB record.