Convair CV-580

Operator:

Registration:

N5825

Flight Phase:

Flight Type:

Survivors:

Site:

Schedule:

Washington DC – Harrisburg – Bradford – Erie – Detroit

MSN:

386

YOM:

1956

Flight number:

AL737

Location:

Bradford

Pennsylvania

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

5761

Captain / Total hours on type:

499.00

Copilot / Total flying hours:

8220

Copilot / Total hours on type:

738

Aircraft flight hours:

27285

Circumstances:

Allegheny Airlines Flight 737 was a scheduled passenger flight from Washington, DC, to Detroit, MI, with en route stops at Harrisburg, Bradford, and Erie, PA. The flight was uneventful until it arrived in the Bradford area, about 20:22. About 20:23, Erie Approach Control asked flight 737 to report their distance to the airport: "Allegheny seven thirty seven, what are you showing DME from Bradford?". Upon which the crew replied, "Fifteen". Erie Approach Control then instructed, "... descend and cruise four thousand via Victor thirty three and cleared for the VOR thirty two (runway 32) approach to the Bradford Airport, report leaving six and Bradford's current weather sky partially obscured, measured ceiling eight hundred overcast, visibility one and one half and light snow showers, wind one seventy degrees at ten (knots) Bradford altimeter twenty nine point four nine." At ten miles from the airport Flight 737 asked for clearance to make its instrument approach to runway 14 instead of runway 32. The Bradford FSS Specialist obtained approval for this change from Erie Approach Control and so advised the flight. At 20:31 the flight reported completing the procedure turn inbound. The Convair clipped treetops 4,7nm short of the airport and cut a swath through trees bordering a fairway of the Pine Acres Golf Course. The aircraft came to rest inverted. Both pilots and 9 passengers were killed while 17 other occupants were injured. The aircraft was destroyed.

Probable cause:

Investigations were unable to determine precisely the probable cause of this accident. Of some 13 potential causes examined by the Board, three remain after final analysis. They are:
- Misreading of the altimeter by the captain,
- A malfunction of the captain's altimeter after completion of the instrument approach procedure turn, and
- A misreading of the instrument approach chart. Of these three, no single one can be accepted or rejected to the exclusion of another based on the available evidence.

Final Report:

Crash of a Convair CV-580 in Chicago: 28 killed

Date & Time: Dec 27, 1968 at 2022 LT

Type of aircraft:

Operator:

Registration:

N2045

Flight Phase:

Flight Type:

Survivors:

Site:

Schedule:

Minneapolis – Wausau – Green Bay – Manitowoc – Milwaukee – Chicago

MSN:

369

YOM:

1968

Flight number:

NC458

Location:

Chicago-O'Hare

Illinois

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

10972

Captain / Total hours on type:

123.00

Copilot / Total flying hours:

2421

Copilot / Total hours on type:

526

Aircraft flight hours:

27180

Circumstances:

On final approach by night to Chicago-O'Hare Airport, at an altitude of 200 feet, the captain decided to make a go-around when the airplane lors height, struck the ground then crashed inverted onto a hangar. Three crew members, 24 passengers and one people on the ground were killed while 18 other were injured.

Probable cause:

Spatial disorientation of the captain precipitated by atmospheric refraction of either the approach lights or landing lights at a critical point in the approach wherein the crew was transitioning between flying by reference to flight instruments and by visual reference to the ground.

Final Report:

Crash of a Convair CV-580 in Bradford: 20 killed

Date & Time: Dec 24, 1968 at 2012 LT

Type of aircraft:

Operator:

Registration:

N5802

Flight Phase:

Flight Type:

Survivors:

Site:

Schedule:

Detroit – Erie – Bradford – Harrisburg – Washington DC

MSN:

410

YOM:

1957

Flight number:

AL736

Location:

Bradford

Pennsylvania

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

6701

Captain / Total hours on type:

1477.00

Copilot / Total flying hours:

4330

Copilot / Total hours on type:

928

Aircraft flight hours:

29173

Circumstances:

Allegheny Airlines Flight 736 departed Detroit, MI for a flight to Washington, DC with intermediate stops at Erie, Bradford and Harrisburg, PA. The Convair CV-580 took off from Erie at 19:46. At 20:06 Flight 736 reported over the VOR outbound at the beginning of the instrument approach procedure. Erie Approach Control then told the crew to contact the Bradford Flight Service Station (FSS). At 20:08:47 the flight reported that they were doing the procedure turn inbound for runway 32 and Bradford FSS told them wind was 290 degrees at 15 knots. The Convair descended in light snow showers until the aircraft contacted trees along terrain which had an average upslope of 1.5deg some 2,5 NM short of the runway. The airplane cut a swath through the trees and impacted the ground at a point 800 feet from the initial tree contact. The fuselage came to rest inverted.

Probable cause:

The continuation of the descent from the final approach fix through the Minimum Descent Altitude and into obstructing terrain at a time when both flight crewmembers were looking outside the aircraft in an attempt to establish visual reference to the ground. Contributing factors were the minimal visual references available at night on the approaches to the Bradford Regional Airport; a small but critical navigational error during the later stages of the approach; and a rapid change in visibility conditions that was not known to the crew.

Final Report:

Crash of a Convair CV-580 in Santa Barbara

Date & Time: Nov 12, 1968 at 1728 LT

Type of aircraft:

Operator:

Tex Johnson Inc.

Registration:

N73135

Flight Phase:

Flight Type:

Training

Survivors:

Site:

Schedule:

Santa Barbara - Santa Barbara

MSN:

YOM:

1968

Location:

Santa Barbara

California

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

4741

Captain / Total hours on type:

866.00

Circumstances:

Following an uneventful training flight in the region of Santa Barbara Airport, the aircraft belly landed, slid for few dozen yards and came to rest on the runway. All four occupants escaped uninjured while the aircraft was damaged beyond repair.

Probable cause:

The accident was caused by the combination of the following factors:
- The student pilot failed to extend the landing gear on approach,
- Inadequate supervision of flight on part of the pilot-in-command,
- The crew failed to use the approach checklist,
- The landing gear warning horn was inoperative for undetermined reason.

Final Report:

Crash of a Convair CV-580 near Marseilles: 38 killed

Date & Time: Mar 5, 1967 at 2007 LT

Type of aircraft:

Operator:

Registration:

N73130

Flight Phase:

Flight

Flight Type:

Survivors:

Site:

Plain, Valley

Schedule:

Chicago – Lafayette – Cincinnati – Columbus – Toledo – Detroit

MSN:

YOM:

1952

Flight number:

LK527

Location:

Marseilles

Ohio

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

22425

Captain / Total hours on type:

403.00

Copilot / Total flying hours:

4166

Copilot / Total hours on type:

250

Aircraft flight hours:

16216

Circumstances:

While descending to Toledo Airport and flying at an altitude of 7,000 feet, all four propeller blades on the right engine detached simultaneously. The blade number two penetrated the fuselage, causing a sudden cabin decompression. The pilot lost control of the airplane that entered a dive and eventually crashed in an open field located two miles southeast of Marseilles, Ohio. The aircraft was totally destroyed and none of the 38 occupants survived the crash.

Probable cause:

Failure of the right propeller due to the omission of the torque piston nitriding process during manufacture, and the failure of manufacturing quality control to detect the omission.
The following findings were reported:
- Loads on the torque cylinder caused by the failed torque piston of the n° 3 blade of the right propeller exceeded the finite fatigue of the cylinder and it failed in fatigue,
- The loss of oil pressure in the right propeller due to the failed torque cylinder caused the propeller pitch to decrease at a rate which exceeded the propeller pitch lock capability,
- The right propeller oversped, causing the blades to separate in overstress,
- The n°2 propeller blade of the right propeller penetrated the fuselage, destroying the structural integrity to the extent that together with the force of a right yaw attending the propeller separation, the fuselage failed along the line of the propeller penetrations,
- The torque piston n°3 blade had not been nitrided to surface hardening of the helical splines during the manufacture,
- The omission of the nitriding process was not detected by inspection,
- The omission of the nitriding process was associated with the movement of 10 torque pistons from the normal production flow to the Allison laboratory and return to the production process,
- The Allison quality control system lacked the accountability necessary to assure the requisite quality of the individual parts,
- The metal contamination oil check to isolate defective torque piston did not serve the intended purpose,
- Allison underestimated the seriousness of the defective torque piston problem.

Final Report:

Crash of a Convair CV-580 in Midland

Date & Time: Dec 21, 1963 at 1142 LT

Type of aircraft:

Operator:

Registration:

N7601

Flight Phase:

Executive/Corporate/Business

Flight Type:

Survivors:

Site:

MSN:

452

YOM:

1960

Location:

Midland

Texas

Country:

Region: