Investigation brief · generated 2026-10-09 · source: NTSB public docket and accident database
BOEING 757 — Las Vegas, NV, USA, 2008-08-06
NTSB number
ENG08IA038
Operator
DELTA AIR LINES INC
Registration
N666DN
Highest injury
No injury
Regulation
Part 121
Damage
—
Cohort
Part 121 airline
Recorder data
Tier 1 — decoded recorder tables
Every sentence below is taken directly from NTSB records — the accident database, the docket's recorder reports and the Board's findings — with its source noted. Nothing is paraphrased or inferred.
NTSB summary
The Delta Air Lines Boeing 757 airplane had just started its takeoff roll from the McCarran International Airport, Las Vegas, Nevada, when the right engine, a Pratt & Whitney (P&W) PW2037, experienced an uncontained release of high pressure turbine material. The examination of the engine revealed a hole in the high pressure and low pressure turbine case flanges at the bottom of the engine in line with the 2nd stage turbine rotor. The engine was removed from the airplane and shipped to Delta's Technical Operations Center for disassembly. The disassembly revealed four adjacent 2nd stage turbine blades were missing. In addition, the 2nd stage turbine hub had four blade retaining lugs that were fractured. Metallurgical examination of the fractures determined the fractures were due to fatigue at elevated temperatures from multiple origins along the blade slot serrations. The metallurgical examination also revealed that there were no material defects in the hub. A dimensional inspection of the hub's blades slots showed that they were missing material. Delta reported that they had to use a grit blasting procedure that was more agressive to remove the varnish-like scale from the hub in order to clean it sufficiently to permit the fluorescent penetrant inspection. Although the incident hub was only grit blasted one time, maintenance records for another PW2037 2nd stage hub that was found to have multiple cracks in the blade slots showed that it had been grit blasted multiple times to clean the hub. Grit blasting tests conducted by P&W showed that if the appropriate grit blasting procedures were not adhered to that significant material loss could result.
The engine experienced an uncontained release of high pressure turbine material due to fatigue cracks that occurred on four consecutive blade retainig lugs on the 2nd stage turbine hub. The cracked lugs resulted in the release of four 2nd stage turbine blades that penetrated the engine's cases and nacelle. The lugs cracked due to loss of material and resultant increase in stress load on the blade slot serrations due to excessve grit blasting when the hub was being overhauled by Delta Air Lines. Contributing to the uncontained incident was the FAA's and Pratt & Whitney's failure to act in a timely manner when another PW2037 2nd stage turbine hub was found to have multiple cracks in the blade retaining lugs.
Verbatim, NTSB determination.
Flight data recorder
— 53,367 samples, 33 parameters, 24:56:50.0 to 25:24:50.0.
Parameter
Max
at
Min
at
Final
at
Pressure altitude ft
2,127.0
25:13:32.5
2,089.0
25:17:52.5
2,101.0
25:24:49.5
Ground speed kts
7.0
25:13:23.8
0.0
24:57:04.8
0.0
25:24:49.8
Pitch attitude deg
0.4
25:21:33.0
-1.1
25:14:37.0
0.2
25:24:49.0
Roll attitude deg
1.1
25:14:42.2
-1.1
25:13:25.2
0.0
25:24:49.2
Vertical acceleration g
1.1
25:24:12.9
0.8
25:24:12.5
1.0
25:24:49.9
Magnetic heading deg
258.4
25:24:12.8
75.6
25:14:26.8
254.9
25:24:49.8
Computed from the docket's tabular attachment; times as recorded (local or SRN as published).
Sequence of events (FDR factual report)
Time
Event
Page
15:45 PDT
Delta Airlines 624, a Boeing 757-232 equipped with Pratt & Whitney PW2037 engines, experienced an uncontained failure in the turbine area of the No. 2 (right) engine
1
N/A
The crew received a No. 2 engine fire warning light and rejected the takeoff
1
N/A
Smoke was observed from the No. 2 engine at the time the takeoff was rejected
1
N/A
Metal debris was found on the runway after the airplane had taxied clear
1
N/A
Examination of the engine at the gate revealed a hole in the engine cowl that was in line with a hole in the high pressure turbine case
1
SRN 91454
The Eng2 Vib parameter shows a rise in engine vibration
4
SRN 91462
The Eng2 Fire indication is set
4
Extracted by claude-sonnet-5; 6 of 7 stated events verified against the raw recorder data.