GAA19CA234

NTSB accident investigation · Cessna T310 · Philadelphia, PA · March 24, 2019

Accident · No injuriesData collectionFinal report
Date
March 24, 2019, 15:30 local (19:30 UTC)
Place
Philadelphia, PA
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N358MNCessna T310
Defining event
Landing: Landing gear not configured
Weather
Visual (VMC) · Day
Status
Completed · report November 6, 2019
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20190324001919A
Case key
99347

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The pilot’s and flight instructor's failure to verify that the landing gear were extended, which resulted in a gear-up landing. Contributing to the accident was the flight instructor’s inadvertent pulling of the landing gear motor circuit, which prevented the landing gear from extending.

Findings · 5

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Attention/monitoring: task monitoring/vigilancePersonnel issues › Psychological · Student/instructed pilotCessna T310R: 2 casesAll aircraft: 330 casesProbable cause
Attention/monitoring: task monitoring/vigilancePersonnel issues › Psychological · Instructor/check pilotCessna T310R: 2 casesAll aircraft: 330 casesProbable cause
Landing gear system: gear extension and retract sysAircraft › Aircraft systems · Not used/operatedCessna T310R: 3 casesAll aircraft: 416 casesProbable cause
Use of equip/info: use of equip/systemPersonnel issues › Task performance · Instructor/check pilotCessna T310R: 1 caseAll aircraft: 1,391 casesProbable cause
Landing gear systemAircraft › Aircraft systems · Unintentional use/operationCessna T310R: 1 caseAll aircraft: 113 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The flight instructor in the retractable-landing gear, multiengine airplane reported that, while performing aerial survey training for a newly hired pilot, the airplane was slowed to the mission airspeed of 117 knots, which meant reduced power and the use of more than 15° of flaps. He added that he then pulled the landing gear warning circuit breaker to silence the landing gear warning horn to ensure clear communication but that he did not pull the landing gear motor circuit breaker. The pilot receiving instruction reported that he did not know that the instructor had pulled the landing gear warning circuit breaker. The instructor further reported that, while returning to the departure airport, the landing checklist was "accomplished" 15 to 20 miles from the airport. He saw that the pilot was "falling behind on power and descent management" and that the airplane was high and fast for the approach. The instructor advised the pilot to correct but then began to assist the pilot when it "was taking longer [than anticipated.]" The airplane decelerated into the white airspeed arc, and the instructor moved the landing gear selector switch into the down position and added full flaps. He added that, because the flaps were added shortly after the landing gear selector switch was put into the down position, he could not tell by the flight characteristics that the landing gear had not extended. Neither he nor the pilot noticed that there was no green down-and-locked position light indicator. The airplane landed with the landing gear retracted. The airplane sustained substantial damage to the fuselage and both engines. The instructor added that, while configuring the airplane on the runway, he observed that the landing gear warning horn and landing gear motor circuit breakers were tripped. The director of maintenance reported that, during a postaccident examination, the airplane was lifted onto jacks and an emergency gear extension and three electrical landing gear retractions were conducted, and no defects were found. In a photograph provided by the flight instructor, the landing gear warning horn and landing gear motor circuit breakers are right next to each other. Despite the instructor's statement that he did not pull the landing gear motor switch, given the proximity of the breakers to each other, it is likely that the pilot inadvertently pulled the landing gear motor switch when he pulled the landing gear warning horn switch, which prevented the gear from extending. The airplane manufacturer's Pilot's Operating Handbook contained a note in the section titled, "Landing Gear Warning Horn," which states, Do not pull landing gear warning circuit breaker to silence horn as this turns off the landing gear control relay, thus the landing gear cannot be retracted.

Factual narrative

The flight instructor in the retractable landing gear, multi-engine airplane reported that, while performing aerial survey training for a newly hired pilot, the airplane was slowed to the mission airspeed of 117 knots, which meant reduced power and the use of more than 15° of flaps. He then pulled the circuit breaker to silence the landing gear warning horn to ensure clear communication, but did not pull the landing gear motor circuit breaker. The pilot receiving instruction reported that he did not know that the instructor had pulled the circuit breaker. The flight instructor further reported that, while returning to the departure airport, the landing checklist was "accomplished" 15 to 20 miles from the airport. He observed that the pilot was "falling behind on power and descent management" and the airplane was high and fast for the approach. The instructor advised the pilot to correct but then began to assist the pilot when it "was taking longer [than anticipated.]" The airplane decelerated into the white airspeed arc, and the instructor moved the landing gear selector switch into the down position and added full flaps. He added that, since the flaps were added shortly after the landing gear selector switch was put into the down position, he could not tell by the flight characteristics that the landing gear had not extended. Neither he nor the pilot observed that there was no green down and locked position light indicator. The airplane landed with the landing gear retracted. The flight instructor added that, while configuring the airplane on the runway, he observed that the landing gear warning horn and landing gear motor circuit breakers were tripped. The airplane sustained substantial damage to the fuselage and both engines. The director of maintenance reported that, during a postaccident examination, they lifted the airplane onto jacks and performed an emergency gear extension. He added that they then did three electrical landing gear retractions and no defects were found. In a photo provided by the flight instructor, the landing gear warning horn and landing gear motor circuit breakers are immediately next to each other. The airplane manufacturer pilot operating handbook contains a note in section titled "Landing Gear Warning Horn", which states, Do not pull landing gear warning circuit breaker to silence horn as this turns off the landing gear control relay, thus the landing gear cannot be retracted.

Aircraft

Registration
N358MN
Reported as
Cessna T310 (R)
Category
Airplane
Serial number
310R0881
Built
1976
Airframe hours
7,124.8
Engines
Continental TSIO-520-EB, 300 horsepower, reciprocatingContinental TSIO-520-EB, 300 horsepower, reciprocating
Damage
Substantial damage
Flight
Other work use · Part 91
Operator
Keystone Aerial Surveys Inc
Registered owner
Keystone Aerial Surveys Inc
Airworthiness certificate
Standard, Normal
Last inspection
Annual · December 6, 2018
Departed
FRG · Farmingdale, NY
Destination
PNE · Philadelphia, PA
Airport
PNE · Northeast Philadelphia, runway 24, 7,000 × 150 ft, asphalt
Equipment
Electronic flight bag or handheld device, Stall warning system, Auto-pilot

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
47
Injuries
None
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Last flight review
March 27, 2018
Seat
Right
Restraint
3-point
Flight hours
7,636 total · 3,800 in this make and model · 7,611 as pilot in command · 54 in the last 90 days · 35 in the last 30 days
Role
Pilot
Age
26
Injuries
None
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
February 25, 2018
Seat
Left
Restraint
3-point
Flight hours
849 total · 12 in this make and model · 704 as pilot in command · 14 in the last 90 days · 14 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
250° at 12 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
63 °F, dew point 19 °F
Altimeter
30.09 inHg
Observed at
KPNE, 1 nm away

Docket · 6

The files NTSB released with the investigation on June 27, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.6 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.