- Date
- May 12, 2014, 19:30 local (23:30 UTC)
- Place
- Boston, MA
- Injuries
- 166 uninjured
- Damage
- Substantial damage
- Phase of flight
- Pushback/towing
- Aircraft
- N933DNMcdonnell Douglas MD90 - 30
- Defining event
- Pushback/tow-engine not oper: Landing gear collapse
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 30, 2020
- Report
- Approved by Office Director
- NTSB office
- Major Investigations Division
- FAA report
- 20140512008291A
- Case key
- 89211
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 captain's failure to verify the communications between himself and the tug operator, which resulted in him applying of brakes while the airplane was being pushed back from the gate by the tug with tow bar attached.
Findings · 2
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.
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 May 12, 2014, at about 1737 eastern daylight time (EDT), Delta Airlines flight 1612, a Boeing MD-90, N933DN, experienced a partially collapsed nose gear during pushback from the gate at Boston Logan International Airport (KBOS), Boston, Massachusetts. The passengers and crew exited the aircraft via the jet bridge and there were no injuries. The flight was operating as a 14 Code of Federal Regulations Part 121 regularly scheduled passenger flight between KBOS and Minneapolis-Saint Paul International Airport (KMSP), Minneapolis, Minnesota. According to the flight crew, during pushback they received a new route clearance due to weather along the route. The captain and first officer discussed how they would handle the associated tasks, and agreed they would load the new route and then contact dispatch after the engine start had been accomplished. The crew stated the interphone conversation quality was degraded due to low volume, and there was considerable radio traffic on both clearance delivery and ramp frequencies. As the flight crew finished coordinating tasks, the captain heard on the interphone what he believed was "set brakes" and, because he did not discern any aircraft motion, began to apply the brakes. The airplane immediately shook and several warnings went off in cockpit. According to the tug operator, while at the gate he received brakes released and clear to push from the flight crew, and he proceeded to push the airplane off of the gate and to the area where it was clear to start engines. As they airplane approached the engine start spot, the tug operator stated "cleared to start", and the airplane immediately stopped, and the tug operator saw the airplane nose immediately drop and the nose gear partially collapse. Further inspection revealed the airplane sustained substantial damage to the nose landing gear assembly.
Factual narrative
On May 12, 2014, at about 1737 eastern daylight time (EDT), Delta Airlines flight 1612, a Boeing MD-90, N933DN, experienced a partially collapsed nose gear during pushback from the gate at Boston Logan International Airport (KBOS), Boston, Massachusetts. The passengers and crew exited the aircraft via the jet bridge and there were no injuries. The flight was operating as a 14 Code of Federal Regulations Part 121 regularly scheduled passenger flight between KBOS and Minneapolis-Saint Paul International Airport (KMSP), Minneapolis, Minnesota. According to the flight crew, during pushback they received a new route clearance due to weather along the route. The captain and first officer discussed how they would handle the associated tasks, and agreed they would load the new route and then contact dispatch after the engine start had been accomplished. The crew stated the interphone conversation quality was degraded due to low volume, and there was considerable radio traffic on both clearance delivery and ramp frequencies. As the flight crew finished coordinating tasks, the captain heard on the interphone what he believed was "set brakes" and, because he did not discern any aircraft motion, began to apply the brakes. The airplane immediately shook and several warnings went off in cockpit. According to the tug operator, while at the gate he received brakes released and clear to push from the flight crew, and he proceeded to push the airplane off of the gate and to the area where it was clear to start engines. As they airplane approached the engine start spot, the tug operator stated "cleared to start", and the airplane immediately stopped, and the tug operator saw the airplane nose immediately drop and the nose gear partially collapse. Further inspection revealed the airplane sustained substantial damage to the nose landing gear assembly.
Aircraft
- Registration
- N933DN
- Reported as
- Mcdonnell Douglas MD90 - 30 (30)
- Category
- Airplane
- Serial number
- 53543
- Built
- 1997
- Airframe hours
- 31,006
- Engines
- International Aero Engines V2500, 28,000 lbs thrust, turbo fanInternational Aero Engines V2500, 28,000 lbs thrust, turbo fan
- Damage
- Substantial damage
- Flight
- Part 121
- Operator
- Drelat Air Lines, Inc.
- Registered owner
- Wells fargo Delaware Trust Co Trustee
- Airworthiness certificate
- Standard, Transport
- Last inspection
- Continuous airworthiness · May 12, 2014
- Departed
- KBOS · Boston, MA
- Destination
- MSP · Minneapolis, MN
- Flight plan
- IFR
- Airport
- KBOS · Boston Logan International
- Equipment
- Electronic multifunction display, Electronic primary flight display, Onboard weather, Stall warning system, Angle of attack indicator, Auto-pilot, Data recorder
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
- 53
- Injuries
- None
- Certificates
- Commercial, Airline transport
- Airplane ratings
- Single-engine sea, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Unknown
- Last flight review
- October 15, 2013
- Seat
- Left
- Restraint
- 5-point
- Flight hours
- 12,066 total · 1,450 in this make and model · 7,934 as pilot in command · 172 in the last 90 days · 3 in the last 24 hours
- Role
- Co-pilot
- Age
- 36
- Injuries
- None
- Certificates
- Airline transport, Commercial
- Airplane ratings
- Multi-engine land, Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Unknown
- Last flight review
- July 19, 2013
- Seat
- Right
- Restraint
- 5-point
- Flight hours
- 3,575 total · 773 in this make and model · 221 in the last 90 days · 3 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 190° at 10 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 75 °F, dew point 48 °F
- Altimeter
- 29.96 inHg
- Observed at
- KBOS
Docket · 1
The files NTSB released with the investigation on March 31, 2020, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.7 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.