INVESTIGATION CATALYST
Quality Assurance Tutorial
© 2004 by Starline Software Ltd.
Step 4: Convert, format and document the actions in the accident report (continued).

NOTE: If you have completed the witness statement analysis tutorial, you may wish to enter data into the INVESTIGATION CATALYST Matrix directly from the marked up report.

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The following commentary describes how EBs are created from the accident report text. The text of the report is quoted, and then the following bulleted line discusses the EB preparation.


Again pilot (X) made an approach at 90 mph and 25deg. flaps.
  • EB 1 = Pilot established approach at 90 mph and 25 deg flaps

    He stated
  • This is not really an EB for the accident scenario, but rather what happened during the investigation. No EB but the next part of the expression is.

    that he touched down
  • he refers to pilot, but actually it was the aircraft that touched down on the runway. Therefore, using the unique name of the aircraft, EB 2 = N4668J touched down on runway approximately 50 feet past the runway threshold numbers.

    He raised
  • Here, He is the pilot, so EB 3 = Pilot raised the flaps,

    then proceeded to apply the toe brakes.
  • the actor is still He, so EB 4 = pilot applied the toe brakes

    At this point, he claims
  • another action, but part of the investigation rather than the accident - EB 5 would discarded.

    the aircraft pulled to the right sharply,
  • this is direct - EB 6= N4668J pulled to the right sharply

    and he straightened its path
  • EB 7 = pilot straightened aircraft path by use of rudder.

    Mr. (X) now attempted stopping the aircraft by applying the hand brake and foot brakes.
  • This is complicated as stated. The actions were EB 8 = Pilot applied hand brake and EB 9 = Pilot applied foot brakes. The X now attempted may be superfluous in this case, unless that decision was the result of considering other options. If so, this decision making process needs to be explored with the Pilot.

    This time the aircraft started off toward the left of runway centerline.
  • Since EBs focus on the initiation of a change of state, the verb begin is useful. For example, EB 10 would be N4668J began to travel toward left of runway centerline - long but all the elements are needed to depict that the aircraft began changing direction.

    N4668J went off the departure end of the runway, left of centerline.
  • This describes the aircraft's movement past a certain point in space. The EB 11 = N4668J went off the runway departure end left of centerline.

    His estimated speed(A) at this time was approximately 30 mph.
  • The action inferred here is the estimation of the speed at which the aircraft was traveling. Unfortunately, the report in unclear about whom made the estimate, and when it was made. If the pilot estimated the speed as part of the decision affecting what he did, it should be converted into an EB if it was an input into a subsequent action. Otherwise, it can be appended to EB 8 it pilot verifies this was the purpose of the estimate. Alternatively it could be said that EB A = N4668J decelerated to 30 mph at end of runway.

    He traveled through 10 feet of grass,
  • Pronoun problems again - tentatively, assume the writer probably was referring to the aircraft traveling through the grass, since the pilot and passengers (PX) were still on board. EB 12 = N4668J traveled through 10 ft. of grass.

    then his main landing gear struck a small trench,
  • nothing subtle until you try to picture what struck the trench, and then it gets fuzzy - most probably it was the wheel, rather than the main landing gear. Use what witness says until you get more accurate data. The trench needs to be identified more clearly, with a reference to a sketch, for example. But at present EB 13 = main landing gear struck small trench

    the aircraft then struck a dirt pile
  • Direct, at first glance. However, the aircraft is a large object - did the entire aircraft strike a large dirt pile, or some parts of it? For the moment, EB 14 = N4668J struck dirt pile.

    where it came to rest.
  • This also seems direct until you try to visualize the aircraft at rest. Did it come to rest on the dirt pile, where it struck it, or where? Again for the moment, use EB 15= N4668J came to rest at dirt pile.

    Pilot and passengers exited N4668J without injury.
  • More than one EB here. Technically, each person should be treated separately if, for example, injury or rescue had been involved. For this exercise, EB 16a = pilot exited aircraft uninjured and EB 16b = passengers (PAX) exited aircraft uninjured are acceptable.

    Examination of the accident scene of 11-29-79 by EA-GADO-11 maintenance and operations personnel disclosed the following:
  • These phrases refer to what investigators did, so no EBs are required for these actions. However the results of the examination reveal some inferred actions, as follows. Runway 18 showed one tire skid mark(B) which measured approximately 300 feet long.
  • The skid mark description implies that a tire skidded along the runway for 300 feet and then kept skidding until the tire reached the dirt pile. The next phrases indicate where it started. These words infer EB B = tire skidded 300 feet on runway.

    It started(C) on runway centerline
  • EB C = tire began skidding and on runway centerline, 300 feet from end of runway

    traveled to the end, gradually traveling toward the left edge.
  • EB 18 would be 'tire started skidding toward left edge of runway

    From the end of the runway hardtop, the skid mark went through(D) the grass
  • the implied event, including information from prior data, is EB D = tire skidded through 10 feet of grass at end of runway.

    across a 14 inch wide trench(E),
  • Here we find out more about what struck the trench. The skid mark implies that the skidding tire skidded the trench so EB E (and EB 12) actually are the same - ? tire skidded across 14 in wide trench.

    terminated<(F) at the dirt pile.
  • This one identifies what struck the dirt pile - the skidding wheel. So EB F = skidding tire struck dirt pile.

    Examination of N4668J was conducted(G) on 11-29-79 in a hangar at (X) Airport
  • this action is another one that refers to the investigation so there is no EB G that should be noted.

    where the aircraft had been moved(H) to protect it from vandalism.
  • Same as G. No EB H.

    'The left wing was deformed(I), buckled(J) and wrinkled(K) at the rear spar, starting at the wing root and traveling outboard for approximately 7 feet.

  • This is the first of three phrases implying something stressed the left aircraft wing, doing the damage described. We can speculate that the skidding wheel striking the ditch produced the damaging stresses, but we can't conclude that from the information provided. So, EB I = ? deformed left wing, EB J = ? buckled left wing EB K = ? wrinkled left wing at rear spar etc. If the trench did produce the stresses that produced the damage, that would be the actor (the 'stressor') in these EBs.

    Rivets were popped(L) and skin wrinkled(M) on the left wing lower side at the area behind the left main gear well.
  • As above, this sentence contains a series of implied events that resulted in the observed damage to the left wing lower side. Thus EB L = ? popped rivets on left wing lower side, and EB M = ? wrinkled skin on left wing lower side.

    The right main landing gear disc brake assembly had failed(N) at the area were it is welded to the brake disc housing.
  • This is a good example of why 'failed' is an undesirable word to use in EBs: it offers no information about what happened - did parts separate, bend, twist, rotate, or what did they do? The next sentence implies that corrosion was implicated in some way. In this instance, the EB N = right main landing gear disk brake assembly ? (failed?) would be an appropriate way to describe this event, to indicate that more information is needed.

    This area was badly corroded(O) to the point where the metal in this area is paper thin.
  • This implies that something corroded the metal 'in this area' (where 'failure' presumably occurred) but note that it does not explicitly link that the corrosion to what happened. The wording suggests that there is a relationship, but does not make the link between the corrosion, the "failure" and what the aircraft did. This is a common way of implying "causation" in accident reports. However, the best that can be documented for EB O = ? corroded metal in ? area of disk brake assembly.

    Both propeller tips were bent(P) 90deg. and one bend had a crack(Q) 1-1/2 inches long.
  • More implied actions to produce the observed effects, but no clear statement of the stressor was. So, EB P = ? bent propeller tips, and EB Q = ? cracked bend in ? propeller tip.

    Nose wheel gear was torn <(R) and bent (S).
  • Another example of multiple implied events, as above. EB R = ? tore ? nose wheel gear, and EB S = ? bent nose wheel gear

    N4668J had sustained major structural damage to the left wing.(T)
  • This is a categorization statement, rather than the description of an event. An EB T would produce no contribution to understanding what happened.


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