N5880L

Substantial
None

American AA5S/N: AA5-0080

Accident Details

Date
Tuesday, January 19, 2021
NTSB Number
ERA21LA106
Location
Leesburg, VA
Event ID
20210119102531
Coordinates
39.081972, -77.559229
Aircraft Damage
Substantial
Highest Injury
None
Fatalities
0
Serious Injuries
0
Minor Injuries
0
Uninjured
2
Total Aboard
2

Probable Cause and Findings

The weakened structure of the left horizontal stabilizer, which resulted in elevator flutter and subsequent partial separation of the left elevator in flight. Contributing to the accident were the lack of elevator authority while landing due to the damaged left elevator and the inadequate inspection of the airplane, which failed to detect the disbonding of the left horizontal stabilizer.

Aircraft Information

Registration
N5880L
Make
AMERICAN
Serial Number
AA5-0080
Engine Type
Reciprocating
Year Built
1972
Model / ICAO
AA5AA5
Aircraft Type
Fixed Wing Single Engine
No. of Engines
1

Registered Owner (Historical)

Name
SALE REPORTED
Address
6000 DOUGLAS DR N
Status
Deregistered
City
CRYSTAL
State / Zip Code
MN 55429-2314
Country
United States

Analysis

HISTORY OF FLIGHTOn January 19, 2021, about 1055 eastern standard time, an American AA-5, N5880L, was substantially damaged when it was involved in an accident near Leesburg, Virginia. The flight instructor and student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

The flight instructor stated that, while flying direct to Leesburg Executive Airport (JYO), Leesburg, Virginia, in smooth air in a slight descent at 1,500 to 1,700 ft mean sea level while below the yellow arc indicated airspeed, the airplane began shaking and buffeting violently and loudly. The control yoke was also shaking violently, left and right, fore and aft, and the airplane was pitching up and down. He took control of the airplane from the student and initially thought there was an engine issue. He applied carburetor heat, reduced the throttle to idle and slowed to the airplane’s best glide speed, which was 80 mph, and completed the engine failure checklist from memory. He circled left looking for a suitable field in which to perform an emergency landing and declared an emergency to the JYO tower controller. As the instructor proceeded to JYO, the pilot of another airplane flew alongside and reported that the accident airplane’s elevator was “flapping in the wind.”

The flight was cleared to land on runway 17. As the airplane approached the runway, the instructor reduced power to idle and attempted to flare normally. The nose pitched down quickly, impacting the runway, and the airplane skidded on the nose landing gear and propeller. After coming to rest, the airplane was secured and both occupants egressed. AIRCRAFT INFORMATIONThe airplane was equipped with two Garmin G5’s each without an externally removable microSD card. The devices were shipped to the NTSB’s Vehicle Recorder Division; however, since no microSD cards were installed, no flight data was recovered from either of the devices.

The AA-5 Traveler airplane has horizontal stabilizers, elevators, and anti-servo tabs which are constructed using a metal-to-metal bonding process.

The elevator assembly consists of the elevator, and an anti-servo tab which extends the full length of the elevator and is attached to the trailing edge by a piano hinge. The elevator is composed of a torque tube bonded to honeycomb ribs, which are bonded to a one-piece aluminum skin formed around the elevator leading edge and bonded to the rear spar.

The elevator was attached/supported at the inboard and outboard ends. The inboard end of each elevator torque tube was supported by a bearing support bracket attached to the aft side of the horizontal stabilizer spar connector, and the torque tube was mechanically connected to a bellcrank by a bolt, washers, and a nut. The outboard end of each elevator torque tube was supported by a bearing support bracket attached to the outboard face of the outboard rib on the horizontal stabilizer assembly. As assembled, each outboard elevator bearing support bracket was attached with two threaded fasteners that are threaded into nut plates riveted to the interior surface of each outboard rib.

According to the airplane maintenance manual (AMM), at each annual or 100-hour inspection, an inspection of the bond lines for any indication of damage, peeling, or cracks should be performed. The AMM also indicated to inspect the horizontal stabilizers for damage and secure mounting.

In over 45 years, 7 months of airframe maintenance records, there was no entry associated with repairs to the left horizontal stabilizer or outer rib of the left horizontal stabilizer. The airplane’s last 100-hour inspection in accordance with the AMM was completed on December 15, 2020, at a tachometer time of 2,879.3 hours. At the time of the accident, the airplane had accrued about 51 hours since the most recent inspection.

Airworthiness Directive (AD) 76-17-03, associated with delaminations in bonded skin with an effective date of August 30, 1976, was a one-time inspection that was completed on July 15, 1977. AIRPORT INFORMATIONThe airplane was equipped with two Garmin G5’s each without an externally removable microSD card. The devices were shipped to the NTSB’s Vehicle Recorder Division; however, since no microSD cards were installed, no flight data was recovered from either of the devices.

The AA-5 Traveler airplane has horizontal stabilizers, elevators, and anti-servo tabs which are constructed using a metal-to-metal bonding process.

The elevator assembly consists of the elevator, and an anti-servo tab which extends the full length of the elevator and is attached to the trailing edge by a piano hinge. The elevator is composed of a torque tube bonded to honeycomb ribs, which are bonded to a one-piece aluminum skin formed around the elevator leading edge and bonded to the rear spar.

The elevator was attached/supported at the inboard and outboard ends. The inboard end of each elevator torque tube was supported by a bearing support bracket attached to the aft side of the horizontal stabilizer spar connector, and the torque tube was mechanically connected to a bellcrank by a bolt, washers, and a nut. The outboard end of each elevator torque tube was supported by a bearing support bracket attached to the outboard face of the outboard rib on the horizontal stabilizer assembly. As assembled, each outboard elevator bearing support bracket was attached with two threaded fasteners that are threaded into nut plates riveted to the interior surface of each outboard rib.

According to the airplane maintenance manual (AMM), at each annual or 100-hour inspection, an inspection of the bond lines for any indication of damage, peeling, or cracks should be performed. The AMM also indicated to inspect the horizontal stabilizers for damage and secure mounting.

In over 45 years, 7 months of airframe maintenance records, there was no entry associated with repairs to the left horizontal stabilizer or outer rib of the left horizontal stabilizer. The airplane’s last 100-hour inspection in accordance with the AMM was completed on December 15, 2020, at a tachometer time of 2,879.3 hours. At the time of the accident, the airplane had accrued about 51 hours since the most recent inspection.

Airworthiness Directive (AD) 76-17-03, associated with delaminations in bonded skin with an effective date of August 30, 1976, was a one-time inspection that was completed on July 15, 1977. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest upright on the runway with the nose landing gear collapsed. The left elevator remained attached at the inboard bellcrank and supported at the inboard support bearing assembly, but was separated at the outboard attach point. The elevator was displaced down from its normal position hinging on the bellcrank and inboard support bearing assembly. Movement of the control yoke produced movement of each elevator control surface.

Postaccident examination of the airplane following recovery from the runway was performed by representatives of the Federal Aviation Administration (FAA), as well as representatives of the airplane type certificate holder.

Examination of the left horizontal stabilizer revealed that the upper skin at the juncture of the surface and outboard rib showed evidence of upper surface debonding from the rib. The debonding measured approximately 9 1/2”, as measured from the upper horizontal surface training edge forward to the visible termination of the debonding. The end rib displayed an approximate 7/8” vertical crack emanating from the upper edge of the rib at the 7 1/2” location, as measured from the upper horizontal surface trailing edge forward. Corrosion was noted throughout the interior of the left horizontal stabilizer and under the bond lines where debonding occurred and also on the outboard surface of the left horizontal stabilizer outboard rib, just below and just aft of the forward lightening hole. The bearing support assembly, part number (P/N) 301030-501, was missing from the left horizontal stabilizer end rib. A section of the outboard rib was missing from the aft end of the lightening hole to the aft spar of the horizontal stabilizer. The aft spar was structurally damaged.

Examination of the elevator control system revealed no discrepancies with the elevator stops, mass balance weights, or four “idler” pulleys. Control cable tension checks of the upper and lower elevator control cables revealed that the upper and lower cables were less than the minimum specified. The upper and lower cables were a maximum of 12.5 pounds and 18.5 pounds, respectively, less than the lower specified limit. Although there was no maintenance manual requirement for a “Free Play” check of the elevator trim tab for the accident make and model airplane, an inspection of the accident airplane using the procedures for an AA5A or AA5B was performed for the right side and the free play measured 0.031 inch, while the maximum specified for the AA5A or AA5B was 0.27 inch. Rigging check of the elevator using the right elevator revealed the nose-up was 3.0° greater than the maximum limit, while the nose down was 5.8° less than the minimum limit. It was noted that the damage could have affected the measurements.

The right elevator remained attached at the bellcrank and both the inboard and outboard attach points; however, the associated trim tab had disconnected from its inboard control arm and was only attached to the elevator by its hinge attachment.

The horizontal stabilizer assembly, both elevators with trim tabs from the accident airplane, as well as the horizontal stabilizer assembly from another AA5 were sent to the NTSB Materials Laboratory for examination.

According to the NTSB Materials Laboratory Factual Report of the accident airplane components, the aft spars on the horizontal stabilizers were fractured at approximately left station 19 to 20 and right station 14. On the left horizontal stabilizer aft spar, the upper...

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ERA21LA106