CEN21LA388

NTSB accident investigation · Cessna 172 · Iron Mountain, MI · August 3, 2021

Accident · Minor injuriesClass 3 · LimitedFinal report
Date
August 3, 2021, 11:30 local (16:30 UTC)
Place
Iron Mountain, MI · on the ramp
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Taxi
Aircraft
N6778ACessna 172
Defining event
Taxi: Prop/jet/rotor blast/suction
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
Flight Standards District Office, Skywest Airlines
Case key
103772

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 mechanics’ failure to follow procedures for high-thrust operations at the nontowered airport, which resulted in jet blast damage to an airplane taxiing nearby.

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.

Info processing/decision: understanding/comprehensionPersonnel issues › Action/decision · Maintenance personnelCessna 172: 1 caseAll aircraft: 70 casesProbable cause
Knowledge: knowledge of proceduresPersonnel issues › Experience/knowledge · Maintenance personnelCessna 172: 1 caseAll aircraft: 41 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 pilot landed the Cessna 172 at the nontowered airport and taxied toward parking. As the Cessna 172 passed about 200 ft behind a Bombardier CRJ-200 parked on the ramp, two mechanics onboard the CRJ-200 were conducting a maintenance test and were not aware of the Cessna 172. The mechanics increased the CRJ-200’s engine power, and jet blast lifted the Cessna 172’s tail, which resulted in the Cessna 172 nosing down and sustaining substantial damage to the left wing. The mechanics did not follow several of the operator’s procedures for high-thrust maintenance operations at a nontowered airport, including notifying airport management personnel of high-thrust operations, selecting the most appropriate location on the airport, and actively communicating high-thrust intentions on the airport’s common traffic advisory frequency. Their failure to follow these procedures led to their performing high-thrust operations near a taxiing airplane.

Factual narrative

On August 3, 2021, about 1130 central daylight time, a Cessna 172, N6778A, was substantially damaged when it was involved in an accident at Ford Airport (IMT), Iron Mountain, Michigan. The pilot and passenger suffered minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported he landed at IMT, a nontowered airport, and taxied toward parking. As the pilot passed about 200 ft behind a parked Bombardier CRJ-200, he noted that cones were placed around the CRJ-200 and the airplane’s beacon was rotating, but no marshal or spotter was on the ramp. Two mechanics were conducting a maintenance test on the CRJ-200 and were not aware of the taxiing Cessna 172. The mechanics did not announce an intention on the airport’s common traffic advisory frequency to increase engine power. After engine power was increased, jet blast lifted the Cessna 172’s tail, which resulted in the Cessna 172 nosing down and sustaining substantial damage to the left wing when it contacted the ground. The mechanics did not comply with the operator’s procedures for high-thrust maintenance operations at a non-towered airport. The procedures included notification of airport management personnel of high-thrust operations, selecting the most appropriate location on the airport, and actively communicating intentions on the airport’s common traffic advisory frequency. Following the accident, the operator reinforced training and communications to mechanics on the risks of high-thrust maintenance operations at nontowered airports.

Aircraft

Registration
N6778A
Reported as
Cessna 172
Category
Airplane
Serial number
28878
Built
1956
Airframe hours
2,502
Engine
Cont Motor 0-300 SER, 145 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 15, 2021
Departed
IMT · Iron Mountain, MI
Airport
IMT · Ford

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
28
Injuries
Minor
Certificate
Airline transport
Airplane ratings
Single-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
June 21, 2021
Seat
Left
Restraint
4-point
Flight hours
7,109 total · 425 in this make and model · 2,902 as pilot in command · 220 in the last 90 days · 64 in the last 30 days · 0 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 4 knots
Visibility
10 statute miles
Temperature
75 °F, dew point 63 °F
Altimeter
29.99 inHg
Observed at
KIMT
METAR
KIMT 241654Z AUTO 20004KT 10SM FEW021 24/17 A2999

Docket · 4

The files NTSB released with the investigation on December 15, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 5.6 MB in all.