# NTSB FTW98LA037: Cessna 150M, N9182U, San Antonio, TX, October 29, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 29, 1997, 17:06 local (23:06 UTC) - Place: San Antonio, TX - Coordinates: 29.54001, -98.489524 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.5400&lon=-98.4895&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 28, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 20474 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA037 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20474/pdf - Page: https://openairdocs.org/ntsb/FTW98LA037 ## Probable cause inadequate service provided by the ground controller, by clearing the Boeing 727 to taxi after the Cessna 150 was cleared to taxi behind the 727, which led to a wake turbulence (jet exhaust) encounter and damage to the Cessna 150. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Propeller blast or jet exhaust/suction, taxi - control tower service - inadequate, atc personnel(lcl/gnd/clnc) (cause) - wake turbulence - encountered (cause) ## Analysis The pilots of Cessna 150, N9182U, held short of Taxiway Delta to allow Boeing 727, N54333, to pass in front of them. After passing, the 727 came to a complete stop at the intersection of Taxiway Delta and runway 12L. The ground controller (GC) offered the Cessna pilots the choice to hold for the 727 or taxi down the taxiway. The Cessna pilots replied that they would hold. The GC then told the Cessna pilots 'okay pass behind him (the 727) taxi to Wright Flyers use caution you got company coming out of Wright Flyers.' The Cessna pilots acknowledged 'behind the 727 (uh) for Wright Flyers then we'll stay right for that outbound traffic.' The GC then cleared the 727 to proceed across runway 12L. As the 727 was throttled up to cross runway 12, the Cessna had moved into the path of the 727's jet blast & was lifted off the ground. The Cessna then struck the surface with its left wing tip and propeller, and was damaged. The pilots of both aircraft had complied with their respective taxi clearances. The Cessna pilot said that he had previously taxied behind large aircraft at the same place with no problems after receiving similar taxi clearance. He also stated that he would have not proceeded behind the 727, if he was aware that the jet was powering up from a 'dead stop.' ## Factual narrative On October 29, 1997, at 1706 central standard time, a Cessna 150M airplane, N9182U, owned and operated by Wright Flyers Inc., of San Antonio, Texas, was substantially damaged after being rolled over by jet blast while taxiing behind a Boeing 727-231, N54333, owned and operated by Trans World Airlines, at the San Antonio International Airport, San Antonio, Texas. Both occupants, the certified flight instructor and the student pilot, were uninjured. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 instructional flight. The Cessna had just landed after conducting a local training flight and was taxiing back to the ramp when the accident occurred. The flight instructor reported the following information on NTSB Form 6120.1/2 (Pilot/Operator Report): The student landed the airplane on runway 12L and exited the runway at taxiway Alpha. After receiving clearance from Ground Control (GC) to taxi to the their ramp and hold short of taxiway Delta, they taxied the airplane southeast on taxiway Romeo and received a new clearance to pass behind a taxiing Boeing 727. The 727 was passing in front of them from left to right, on taxiway Delta. The Cessna held short of taxiway Delta to allow the 727 to pass in front of them. After passing, the 727 came to a complete stop at the intersection of taxiway Delta and runway 12L. GC then cleared the Cessna taxi behind the 727 and also advised them of another aircraft that was taxiing outbound from the ramp. As this was occurring, GC cleared the 727 to proceed across runway 12L. As the 727 throttled up, the Cessna, which was then in the path of jet blast from the 727, lifted completely off the ground and was rotated to the right. The airplane struck the ground with the left wing tip and propeller and came to rest upright, facing the opposite direction of the taxing 727. Inspection of the aircraft by an FAA inspector revealed that right wing spar was structurally damaged. The following is an excerpt from a certified transcript of the ground communications during the event: 1704:52 Ground Control "cessna niner one eight two uniform a you got the seven twenty seven in sight you can hold for him or taxi down the taxiway and make a left turn on november your choice" 1704:59 N9182U "eight two uniform we'll hold for him 1705:01 Ground Control "okay pass behind him taxi to wright flyers use caution you got company coming out of wright flyers" 1705:05 N9182U "behind the seven twenty seven uh for wright flyers then we'll stay to the right for that outbound uh traffic" 1706:24 Ground Control "t w a forty three thirty three cross runway one two left hold short of one two right" 1706:29 TWA4333 "roger crossin one two left holdin short of one two right" 1706:32 Ground Control "eight two uniform caution jet blast he's moving" 1706:35 N9182U "eight two uniform" 1706:48 Unknown "(unintelligible) are you guys okay" 1706:50 Ground Control "nine one eight two uniform you all right" 1706:52 N9182U "eight two uniform we're fine sir we're going to need somebody to tow this plane off" Ground Control's taxi clearances to all of the aircraft involved were given in compliance with applicable FAA guidelines for ground movement of aircraft. Both the Cessna and Boeing 727 complied with their respective taxi clearances. The pilot of the Cessna stated that he had taxied behind large aircraft before at the same place, and with similar taxi clearances. He also stated that he would have not proceeded behind the 727 if he was aware that the jet was powering up from a "dead stop." ## Aircraft - Registration: [N9182U](https://openairdocs.org/deregistered/N9182U-2006-05-04), registration cancelled 2006-05-04, S/N 15078133, built 1976 (OpenAirDocs) - Reported make and model: Cessna 150M - Registry model: [Cessna 150M](https://openairdocs.org/model/cessna-150m) (registry code 2071830) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15078133 - Airframe hours: 8555 - Engines: Continental O-200-A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Wright Flyers Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 7, 1997, 52 hours before - Departed: SAT - Airport: SAT, San Antonio International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 1,042 total, 834 in this make and model, 965 as pilot in command, 153 in the last 90 days, 43 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 4,600 ft overcast - Temperature: 73 °F, dew point 63 °F - Altimeter: 29.00 inHg - Observed at: SAT ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19971029031119A](https://openairdocs.org/incident/19971029031119A), Oct 29, 1997: Cessna 150M, San Antonio, TX, Substantial damage. Got clearance to taxi behind crossing 727 on a taxiway. Crossed too soon. Wake turbulence blew 150 off ground. (.4) the pilots of Cessna 150, N9182U, held… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.