DCA18CA049

NTSB accident investigation · Embraer S A ERJ170-200LR · Saint Louis, MO · December 18, 2017

Accident · Serious injuriesData collectionFinal report
Date
December 17, 2017, 23:45 local (Dec 18, 2017, 05:45 UTC)
Place
Saint Louis, MO
Injuries
1 serious, 56 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N128SYEmbraer S A ERJ170-200LR
Defining event
Enroute-descent: Cabin safety event
Weather
Instrument (IMC) · Night
Status
Completed · report July 8, 2020
Report
Approved by Office Director
NTSB office
Major Investigations Division
Lead agency
Other
FAA report
20171217024599A
Case key
96503

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 abrupt pitch up maneuver which caused the flight attendant to lose her balance and injure her ankle.

Findings · 1

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.

Use of equip/info: aircraft controlPersonnel issues › Task performance · Flight crewEmbraer S A ERJ 170-200 LR: 1 caseAll aircraft: 9,295 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

On December 17, 2017, about 2345 central standard time, SkyWest flight 5788, an Embraer ERJ700, N128SY, experienced a sudden pitch correction during descent into St. Louis International Airport (STL), St Louis, Missouri. Of the 57 passengers and crew onboard, one flight attendant was seriously injured. The airplane was not damaged. The flight was operating under 14 Code of Federal Regulations Part 121 as a regularly scheduled domestic passenger flight from San Francisco International Airport (SFO) to STL. According to the flight crew, the captain was the pilot monitoring and the first officer (FO) was the pilot flying and was on his second day of initial operating experience (IOE). The air was smooth with no turbulence. Air traffic control requested the flight give its "best forward speed" and cleared it direct to the airport. The crew discussed and planned the descent and after entering the data into the flight management system (FMS), noticed they were past the top of descent point for the 3-degree descent path they had entered. As a result, the captain had the FO select flight level change and the descent rate briefly exceeded 5,000 feet/minute and the airspeed increased. To prevent an overspeed condition, the captain instructed the FO to deploy the speed brakes, but the speed continued to increase, so the captain disconnected the autopilot and pitched the nose up. At the time of the unexpected pitch input, the rear flight attendant (FA) was preparing the galley for landing and was thrown off-balance onto the floor, causing her to twist her ankle. Medically qualified passengers assisted the FA until landing. After landing, the FA was transported to the hospital where she was diagnosed with an ankle fracture.

Factual narrative

On December 17, 2017, about 2345 central standard time, SkyWest flight 5788, an Embraer ERJ700, N128SY, experienced a sudden pitch correction during descent into St. Louis International Airport (STL), St Louis, Missouri. Of the 57 passengers and crew onboard, one flight attendant was seriously injured. The airplane was not damaged. The flight was operating under 14 Code of Federal Regulations Part 121 as a regularly scheduled domestic passenger flight from San Francisco International Airport (SFO) to STL. According to the flight crew, the captain was the pilot monitoring and the first officer (FO) was the pilot flying and was on his second day of initial operating experience (IOE). The air was smooth with no turbulence. Air traffic control requested the flight give its "best forward speed" and cleared it direct to the airport. The crew discussed and planned the descent and after entering the data into the flight management system (FMS), noticed they were past the top of descent point for the 3-degree descent path they had entered. As a result, the captain had the FO select flight level change and the descent rate briefly exceeded 5,000 feet/minute and the airspeed increased. To prevent an overspeed condition, the captain instructed the FO to deploy the speed brakes, but the speed continued to increase, so the captain disconnected the autopilot and pitched the nose up. At the time of the unexpected pitch input, the rear flight attendant (FA) was preparing the galley for landing and was thrown off-balance onto the floor, causing her to twist her ankle. Medically qualified passengers assisted the FA until landing. After landing, the FA was transported to the hospital where she was diagnosed with an ankle fracture.

Aircraft

Registration
N128SY
Reported as
Embraer S A ERJ170-200LR (200LR)
Category
Airplane
Serial number
17000445
Built
2014
Engines
GE CF34-8E5, turbo fanGE CF34-8E5, turbo fan
Damage
No damage
Flight
Part 121
Operator
Skywest Airlines Inc
Registered owner
Skywest Airlines Inc
Airworthiness certificate
Standard, Transport
Departed
SFO · San Francisco, CA
Destination
Saint Louis, MO
Flight plan
IFR

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
Flight instructor
Age
47
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
January 18, 2017
Seat
Left
Restraint
5-point
Flight hours
9,059 total · 2,562 in this make and model · 222 in the last 90 days
Role
Co-pilot
Age
24
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
December 11, 2017
Seat
Right
Restraint
5-point
Flight hours
2,253 total · 15 in this make and model

Weather

Conditions
Instrument (IMC) · Night
Visibility
10 statute miles
Temperature
-54 °F
Observed at
ATC

Docket · 1

The files NTSB released with the investigation on July 13, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 518 KB 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.