Senior Member Guide





        The nature of mishap investigation is such that a Board will inquire at length into subjects which are covered only lightly in familiar resources like NATOPS and O-level maintenance publications. Some inquiries will lead beyond O- and I-level disassembly or testing capability. Impact can so completely disorganize an aircraft that pieces are difficult to identify. Overlaying signatures of impact damage and post-crash fire can confound laymen’s efforts to determine objects’ condition before impact and fire.

        Expediency and curiosity will tempt the Board and hangers-on to dive in and learn while doing. There is jeopardy to personnel and evidence in doing so. If you (or accompaniment) do not know how to do something you are about to attempt, or how to interpret what you find when you have done it---Stop. Get help. Call a pro with knowledge, the right tools and experience.

Who You Gonna Call?

         The resources immediately at hand are squadron and intermediate maintenance personnel, their tools and pubs; these work when the aircraft will yield to wrench-and-screwdriver disassembly. Base civil engineering and CFR personnel can provide brute force assistance (equipment for lifting, digging and cutting). All the former have their place and their limits.

          If component removal is the objective, you can proceed in most cases. If detailed disassembly is (or might later become) your aim for selected components, inquire further. Ask pointedly of the work detail, “Are you equipped for and capable of this operation? Can you interpret what you will see inside?” Anything less than full assurance is reason to delay long enough to task-organize, or to defer the operation to another time and place (layout, EI).

          Some might offer "I dunno" to your inquiries. Press for referral to someone who might know or can find out. Answers and assistance are out there; sometimes the hard part is finding a source.

          The first resort is talent on the government payroll. There is abundant engineering and technical expertise within Naval Air Systems Command and its subordinate commands. Contact the cognizant engineering activity for the aircraft or component of interest. Unit maintenance departments routinely have contact with personnel at Naval Aviation Depots; you will deal with the same for support. NAESU/NATEC representatives and resident manufacturers’ technical representatives have such contacts. The controlling custodian’s aviation logistics section is another which is well connected and can steer you rightly.

          The resource for the airframe might be different than for the engine, other systems or operational issues. Flight performance questions can be entertained by the Test Directorate at Patuxent River. Weapons systems and ordnance will likely fall to China Lake or Indian Head. Appendices to OPNAVINSTs 3750.6_ and 4790.2¬_ list others for ALSS, NVG, tires, etc.

           Beyond naval aviation’s support establishment, other federal agencies have specialized knowledge or capability for research and analysis. Contact Naval Safety Center for guidance to and coordination with such external agencies.

           Manufacturers’ representatives are a second resort. Companies are interested in their products’ performance, and most are willing to send knowledgeable help to the mishap, layout or EI location. Such assistance is usually covered under a continuing-support contract with NAVAIRSYSCOM, but should be cleared through the cognizant class desk or program manager for the aircraft or component involved.

           In every instance, ask EARLY...before evidence is disturbed, perhaps beyond reconstruction. The technical resources you consult will want to see the evidence in as-found condition or something very close to it. You do no one a favor to dismantle an item, submit the loose pieces in a shoebox, and inquire, "Can you figure this out?"

           Use technical assistants appropriately: observe the limits of their expertise or qualification. It is inappropriate to question the airframe maker’s representative on the workings of an engine his company did not design or build. An engineer whose expertise is hydraulic actuators will probably be unprepared for questions on avionics, ejection seat, other things outside his realm.


           Regardless of civilian or government employment, a technician or engineer assisting a safety investigation board is not a member and may not have access to privileged information. His work product (report) is not protected against disclosure; consequently, it must not contain privileged information. The best assurance this will not happen is to avoid sharing it.

           Avoid the appearance of impropriety in evidence access, handling or custody. No contractor or manufacturer representative should have unescorted access to mishap exhibits. Have such personnel accompany a board member or an engineer from the cognizant field activity, competent on the system of interest. Do not leave such guests to putter alone among wreckage or exhibits while the AMB is elsewhere.

           Assistants of every stripe are present for your aid, not you for theirs. You may tell them to hold offsite until you need them or can supervise them. When you assess there is no further need for their presence, you may send them home.

Food Chain

           Many people who arrive to assist a mishap investigation are also part of the string of commands and corporations which designed, built, supplied, maintained, overhauled, scheduled or operated the aircraft. Consequently, they could have interest in the evidence and the investigation's outcome.

           This does not mean you must stay in another hotel, travel separately or sit apart at dinner. It means: Be Discrete. The content of the Board's privileged interviews may not be shared, wholesale or piecemeal; the Board's speculations on cause should not be aired beyond its membership. Simply confine discussion to facts and sterile hypotheses when any within hearing are not admitted past the veil.

Remains, Autopsy, Toxicology

           What follows is explained in greater detail in the Flight Surgeon’s Pocket Guide for Aircraft Mishap Investigation, since they are matters for the medical member. They are generalized here because they bear on Board proceedings and might require your attention when military and civilian jurisdictions cross or generate confusion.

           Custody of decedent’s remains often rests with local law enforcement or affiliated medical authority, more so when the mishap occurs off-base. Custody and procedure vary from state to state. Although procedure in the vicinity of home base should be known to your flight surgeon, mishaps away might cause confusion.

            In some jurisdictions, law might require autopsy for a death other than by natural cause; in others, an apparently accidental death might require only a police or coroner’s determination the occurrence was accidental. Some jurisdictions employ a medical examiner (physician, pathologist); some have a lay coroner.

            If the case falls outside federal jurisdiction, the Board’s medical member should make contact with the local medical examiner or coroner to offer military handling of the remains and use of a military facility; the local authority may decline the offer, or may waive his jurisdiction in favor of federal authority. If local authority retains jurisdiction, have the medical member request attendance at autopsy and distribution on the report. If there are multiple fatalities, or condition of remains portends a difficult case, request attendance of a pathologist or path team from AFIP.

             For proceedings under civilian jurisdiction, have the medical member determine the extent to which the medical examiner will obtain samples, conduct toxicological tests, obtain Xray, conduct dental examination or other wanted examinations. If the procedure under state law is less extensive than desired for the purposes of the SIR, Flight Surgeon’s Report, or JAG Manual investigator’s report, have the medical member request sufficient specimens be obtained or procedures performed to permit supplementary examination by AFIP. This is not a deficiency in civilian proceedings: their focus is law enforcement (criminal investigation). A crime has not been committed, or you would not be in session.


             The Naval Safety Center is tasked by CNO in OPNAVINST 3750.6_ to investigate Navy and Marine Corps aircraft incidents and mishaps. The Center has a division of trained, experienced mishap investigators who travel to assist investigations of most Navy and Marine Corps Class Alfa mishaps.

             The Center’s flight operations, maintenance and aeromedical analysts are Navy and Marine Corps members with recent fleet experience. An extensive database of mishap information can be mined by occurrence, model, type or other criteria.

             The Naval Safety Center can assist in finding resources to accomplish data recovery and analysis. The process requires time-sequenced data (radar, DSU, DFIR, mission/navigation computers).

              Data retrieved from recording devices is factual information when presented without alteration in tabular or graph format. Reconstruction and simulation might involve subjective manipulation and data smoothing, resulting in a privileged product. In other words, the AMB may share with the JAGMan investigator the raw content of any recording device successfully downloaded, but might have to protect a RAPS production as privileged.

              In hard cases for which you cannot find a source, ask the Aircraft Mishap Investigation division at Naval Safety Center; investigators have probably encountered a like problem and know a resource. Examples are: Armed Forces Institute of Pathology, USAF 84th Radar Evaluation Squadron, Naval Research Laboratory, Federal Bureau of Investigation, Federal Aviation Administration and National Transportation Safety Board. More are accessible.


             As mentioned above, the FRCs are a resource for technical support. A FRCs usually is synonymous with cognizant field (or engineering) activity (CFA or CEA), meaning it has the highest level repair capability within the Naval support structure or has engineering oversight for support contracted to other services and civilian repair facilities. FRCs capabilities usually include detailed disassembly, reconditioning, overhaul, and functional test; consequently its personnel are familiar with components’ materials, maintenance and manufacture. Material analysis capabilities are extensive: staff metallurgists and chemists are equipped to perform analyses down to molecular level.

             The issue of FRC support usually comes up twice: early in the field investigation and toward the end of layout. In the first instance, FRC personnel can help identify parts and determine whether they merit further examination or that their condition is unremarkable except for damage explained by impact or post-crash fire. In the second instance, FRC personnel can accomplish detailed test, measurement or examination of selected exhibits the AMB presents. When the FRC sends personnel to the field, one will be designated lead engineer and provide a report of the summary observations or determinations made on the wreckage.

             An engineering investigation is tightly focused on objects the AMB submits for examination, not the whole aircraft. Depending on which activities have cognizance, various parts might go to separate destinations, resulting in as many EI reports.

             Not everything merits engineering investigation. An article known or suspected to have malfunctioned or failed warrants investigation if the question--Why?---has not already been answered. The rationale for others should be: pointed question(s) the Board expects are answerable by an exhibit’s examination, and examination is not possible with local resources. No questions, no fishing expedition. The AMB’s charter to determine mishap cause may not be passed to another as random EIs in hopes something will appear.

             When multiple EI exhibits are inducted at a FRC, a lead engineer will parcel them out to engineers and technicians in appropriate divisions for test (condition permitting) or detailed disassembly. Work on the lot usually proceeds concurrently. The lead engineer writes the report section representing his work and collates subsidiary reports by others. Some components’ examination might take place at another service’s depot, a manufacturer’s plant or an authorized repair station. When components are redistributed in this fashion, the cognizant FRC engineer attends to oversee the process and to record its findings; the EI report will be written by Navy Department personnel.

             An engineering investigation report is an authoritative source of factual information, accessible to safety, administrative or legal proceedings and to public inquiry. An engineer is limited to what can be determined with confidence from the material exhibits, component history cards and maintenance record---hard evidence.

             In the absence of a solid determination among your exhibits (it happens), you might be frustrated that you cannot elicit an engineer’s speculation. As scientist, he is bound to rely on hard evidence, which might be too limited or obscured by damage. You might be tempted to sweeten the pot by offering information you can substantiate only from privileged sources. Don’t. It remains the AMB’s job to determine mishap cause by synthesizing an explanation from a combination of the real and the privileged evidence.

Federal Aviation Administration

             If the aircraft could have been visible to radar, FAA is a potential source of that information regardless of filing, flight rules or squawk. NAVAID status and area weather are also available. If the crew attempted contact or was handled by FAA, additional information is possible: taped radio/telephone communication, pilot reports, and more.

             Make timely requests through the military liaison at FAA regional headquarters. Unless reserved for inquiry, recording media are recycled after 15 days; temporary notes (weather, aircraft routing slips, PIREPs) might be discarded on expiration unless the handling facility has prompt notice that the aircraft was involved in a mishap. FAA personnel may provide witness statements and interviews, although there is considerable formality to such requests. Use the military liaison (NAVREP). At any point the Board entertains FAA functions, services or personnel might be a factor in the mishap, proceed as described in the section on FAA and NTSB participation.

Escape Systems, Flight Equipment, Survival Equipment

             No single activity has cognizance or comprehensive technical knowledge of all Aviation Life Support Systems. Because of interaction among installed restraint or escape systems and equipment airmen wear, a multidisciplinary Mishap Investigation Support Team is available to provide technical support on-site.

             MIST should be requested for mishaps involving major injury or fatality, or when inadequate performance of ALSS is known or suspected. MIST may be requested through the attending Naval Safety Center investigator or directly from NAVAIRSYSCOM.

             A MIST coordinator will head a field team from various activities which support the installed escape system, cartridge-actuated devices, parachute or flight equipment for the involved aircraft.

             Escape systems and survival equipment are intended for one-time use. Even for a successful egress or survival situation (no apparent equipment problem), recovered ALSS equipment should be shipped to NAWCAD Patuxent River for examination and disposal. An EI will not be conducted nor a report written for equipment shipped for disposal. If the equipment’s function is in question, request the EI to obtain a report.

Contact Info: 757-444-3520 Ext: 7813 | POC:
Last Reviewed February 26, 2013