OPS10IA132

NTSB incident investigation · Boeing 737-7H4 · Houston, TX · April 28, 2010

Incident · No injuriesIncident investigationFinal report
Date
April 28, 2010, 12:25 local (17:25 UTC)
Place
Houston, TX
Injuries
140 uninjured
Phase of flight
Takeoff
Aircraft
N242WNBoeing 737-7H4N6YJBell 407
Defining events
Takeoff: Air traffic eventInitial climb: Air traffic event
Weather
Visual (VMC) · Day
Status
Completed · report December 27, 2011
Report
Approved by Office Director
NTSB office
Operational Factors Division
Parties
National Air Traffic Controller Association, William P Hobby Airport, Federal Aviation Administration
Case key
75909

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

On this page

Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

The failure of the local controller to issue control instructions necessary to ensure positive control/standard separation of traffic operating within the Class B airspace.

Findings · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings.

Analysis

A Boeing 737 (B737) was departing from runway 12R and a Bell 207 was departing from the south helipad on a northbound departure route, when the aircraft came within approximately 125 feet vertically and 100 feet laterally at the departure end of runway 12R. The air traffic control tower controller did not issue traffic advisories to the B737 or the Bell 207. The incident occurred during daytime visual meteorological conditions.

Factual narrative

The factual narrative486 words

On Monday, April 28, 2010, at approximately 1225 central daylight time, a Boeing B737-700, N242WN, operating as Southwest Air Lines (SWA) flight 1322, and a Bell 207, N6YJ, operating as Sky2 were involved in a near mid-air collision at the William P. Hobby Airport (HOU), Houston, Texas. The B737 was departing from runway 12R, and the Bell 207 was departing from the south helipad on a north-bound departure route, when the aircraft came within approximately 125 feet vertically and 100 feet laterally at the departure end of runway 12R. The incident occurred during daytime visual meteorological conditions (VMC). The B737 was on a regularly scheduled passenger flight from HOU to Baltimore/Washington International Thurgood Marshall Airport (BWI), and was operating under the provisions of 14 Code of Federal Air Regulation Part 121. The B737 had 135 passengers and a crew of five onboard. The Bell 207 was departing from the south of the airport on an established departure route, and was operating under the provisions of 14 Code of Federal Regulations Part 91. The Bell 207 had one person onboard. No injuries were reported on either aircraft. At approximately 1224, the local controller issued takeoff clearance to the B737 on runway 12R, with departure instructions to turn left to the north. Approximately, twenty six seconds later the Bell 207 contacted the tower requesting a departure route to the north (cougar departure) from the south helipad. The local controller directed the Bell 207 to “use caution from the south pad, cougar departure is approved”. Approximately three seconds later, the local controller instructed the Bell 207 that he had “no restrictions”. The pilot immediately read back the “no restrictions” instructions and proceeded on the departure route. Approximately 20 seconds later the B737 reported to the tower “Hey tower that helicopter is going right across us” and “we made a pretty good duck to miss him”. Simultaneously the Bell 207 had conducted a sharp turn to the right to avoid overflying the departing B737. The aircraft came within an estimated 125 feet vertically and 100 feet laterally from each other, at approximately the 1,000-foot remaining section of runway 12R. The local controller did not issue traffic advisories to the B737 or the Bell 207. The B737 continued on the regularly scheduled flight to BWI, and the Bell 207 continued northbound to operate under visual flight rules (VFR). Radar Data Radar data for this report was obtained from the ASR-9 sensor located at HOU. A graphic showing a close-up view of the two aircraft and their minimum separation have been entered in the docket. The applicable separation standard between VFR and IFR aircraft in class B airspace is visual separation or 500 feet vertically and 1½ miles laterally. At the closest point the aircraft were separated by approximately 100 feet vertically and 125 feet laterally. The controller did not issue any traffic advisories or control instructions to establishand maintain visual separation.

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.

Aircraft · 2

Registration
N242WN
Reported as
Boeing 737-7H4
Category
Airplane
Serial number
32505
Engines
CFM Intl CFM56-7B24, 24,200 lbs thrust, turbo fanCFM Intl CFM56-7B24, 24,200 lbs thrust, turbo fan
Damage
No damage
Flight
Part 121
Operator
Southwest Airlines Co
Registered owner
Southwest Airlines Co
Departed
HOU · Houston, TX
Destination
BWI · Baltimore, MD
Flight plan
Unknown
Airport
HOU · William P. Hobby Airport, runway 12R, 7,602 × 150 ft, concrete

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.

Registration
N6YJ
Reported as
Bell 407
Category
Helicopter
Serial number
53066
Engine
Rolls-Royc 250-C47B, 650 horsepower, turbo shaft
Damage
No damage
Flight
Aerial observation · Part 91
Operator
Helicopters Inc
Registered owner
Helicopters Inc
Airworthiness certificate
Unknown
Departed
HOU · Houston, TX
Destination
HOU · Houston, TX
Flight plan
Unknown
Airport
HOU · William P. Hobby Airport, runway 12R, 7,602 × 150 ft, concrete

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.

Weather

Conditions
Visual (VMC) · Day
Wind
10° at 10 knots
Visibility
10 statute miles
Lowest ceiling
25,000 ft overcast
Temperature
73 °F, dew point 37 °F
Altimeter
30.04 inHg
Observed at
HOU

Docket · 4

The files NTSB released with the investigation on November 9, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 296 KB in all.