Citation Nr: 21062848 Decision Date: 10/12/21 Archive Date: 10/12/21 DOCKET NO. 14-44 465 DATE: October 12, 2021 ORDER Service connection for chronic obstructive pulmonary disease (COPD) (also claimed as bronchitis and pneumonia) is denied. Service connection for prostate cancer is denied. Service connection for diabetes mellitus is denied. Service connection for left hand peripheral neuropathy is denied. Service connection for right hand peripheral neuropathy is denied. Service connection for left foot peripheral neuropathy is denied. Service connection for right foot peripheral neuropathy is denied. Service connection for ischemic heart disease is denied. FINDINGS OF FACT 1. COPD was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 2. Prostate cancer was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 3. Diabetes mellitus was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 4. Peripheral neuropathy of the left hand was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 5. Peripheral neuropathy of the right hand was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 6. Peripheral neuropathy of the left foot was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 7. Peripheral neuropathy of the right foot was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 8. Ischemic heart disease was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 9. The Veteran did not serve in the Republic of Vietnam; did not perform duties on or near the perimeters of military bases in Thailand; did not perform service in the Air Force under circumstances in which he regularly and repeatedly operated, maintained, or served onboard C-123 aircraft; and is not shown by evidence of record to have been exposed to herbicide agents (hereinafter simply referred to as "Agent Orange," while the Board acknowledges that multiple such herbicide agents bearing different names were used) in service. CONCLUSIONS OF LAW 1. The criteria for service connection for COPD, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 2. The criteria for service connection for prostate cancer, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 3. The criteria for service connection for diabetes mellitus, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 4. The criteria for service connection for peripheral neuropathy of the left hand, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 5. The criteria for service connection for peripheral neuropathy of the right hand, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 6. The criteria for service connection for peripheral neuropathy of the left foot, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 7. The criteria for service connection for peripheral neuropathy of the right foot, including based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 8. The criteria for service connection for ischemic heart disease, including as secondary to service-connected disability or based on exposure to Agent Orange, have not been met. 38 U.S.C. §§ 1101, 1110, 1112, 1116, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty continuously from August 1954 to August 1977. The Department of Veterans Affairs (VA) is grateful for his service. He died in June 2012. The appellant is his surviving spouse, and she is recognized as the lawful substitute for the claims the subject of this appeal. See VA 21-0847 dated March 6, 2014; VA Correspondence dated April 12, 2014; see also 38 C.F.R. § 3.1010. SERVICE CONNECTION 1. 8. Service Connection for COPD, Prostate Cancer, Diabetes Mellitus, Peripheral Neuropathy of the Left and Right Hands and Left and Right Feet, and Ischemic Heart Disease In a June 2018 decision, the Board denied the appealed claims, and the appellant appealed those denials to the United States Court of Appeals for Veterans Claims (CAVC). The Secretary filed a brief requesting that Board's decision be vacated and that the case be remanded due to failure of the Board to address a theory of entitlement raised by the appellant at a March 2018 hearing before the undersigned. The unaddressed theory of entitlement is that the Veteran should be presumed to have been exposed to Agent Orange when servicing C-123 aircraft that were used in the spraying of Agent Orange, pursuant to 38 C.F.R. § 3.307(a)(6)(v). In a November 2019 Memorandum Decision, the CAVC vacated the Board's June 2018 decision and required that the Board provide a new decision with adequate reasons and bases including addressing the question of whether service connection for the claimed conditions was warranted based on presumed Agent Orange exposure on the basis of the Veteran having worked on C-123 aircraft. The Board addressed this question of C-123 exposure as well as other bases of claim for the disabilities the subject of appeal by a July 2020 decision. However, the appellant appealed that July 2020 decision, and the Secretary and the appellant filed a Joint Motion for Remand (Joint Motion) approved by the CAVC by a May 2021 Order vacating the July 2020 decision on all the issues the subject of appeal (the same issues on appeal as listed hereinabove) and remanding the case for action consistent with the Joint Motion. The Joint Motion determined that the Board's finding that the Veteran had not had duties which regularly placed him "on or near the perimeter" of air bases in Thailand to be conclusory. The Joint Motion found fault with the Board's failure to define criteria for "on or near the perimeter" of bases in Thailand, including addressing specific evidence in the service personnel records, which service personnel records document his service placing him at four separate Air Force bases in Thailand. The Joint Motion requires that the Board base its determination on personnel records including "evidence of daily work duties, performance evaluation reports or other credible evidence," citing May 2010 C&P Service Bulletin. In relevant parts, still valid portions of the Board's prior decisions are reiterated herein, notwithstanding those prior Board decisions having been vacated for reasons of errors or deficiencies found in the Board's prior decisions which are herein corrected. Because applicable law, regulation, or directive does not define the phrase "on or near the perimeter" of air bases in Thailand for purposes of ascertaining whether regular duties of a soldier placed that soldier on or near the perimeter, the Board adopts the usual legal practice of reasonableness, with ordinary or common meaning in the context. The Board notes that absent an expressly defined term within a statute, "a fundamental canon of statutory construction is that when interpreting a statute, the words of a statute are given 'their ordinary, contemporary, common meaning.'" See Gordon v. Nicholson, 21 Vet. App. 270, 277 (2007). The canons of statutory construction apply to regulations as well as statutes. See Smith (William) v. Brown, 35 F.3d 1516, 1523 (Fed. Cir. 1994). The Board thereby concludes that "on or near the perimeter" of an air base in Thailand for purposes of ascertaining whether a soldier would be at that place as part of his or her regular duties, encompasses those areas where personnel would be expected to regularly be on or near the perimeter if they were assigned duties which would tend to place them on or near the perimeter of an air base, such as the duty areas of a security policeman, security patrol dog handler, or member of the security police squadron at or near the perimeter of the air base, with the focus of such duties being frequently specific to the perimeter of the air base. This is not simply tautological, but rather recognizes that it is the duties placing the soldier on or near the perimeter of the base that must be the focus of the analysis, not a question of how far from the perimeter line "near the perimeter" extends. To do otherwise would force the Board to be roped into an argument about metes and bounds of perimeters of air bases which appears to be at odds with questions of regular duties on or near the perimeter, and hence such an argument may be expected to destroy the rule by corrupting its intended meaning. Duties tending to place a soldier on or near the perimeter of an air base cannot meaningfully be deconstructed to focus merely on the isolated terms "duties," "place," "near," or "perimeter." The Board thus chooses to define the question of duties on or near the perimeter of an air base by the nature of the duties in question, rather than where a particular soldier may or may not have been standing or walking on a particular day in the course of his service, which necessarily could be neither proven nor disproven to any reasonable degree decades after the fact. Thus, the Board concludes that regular duties on or near the perimeter of an air base is defined by the nature of the duties, not the location of the soldier at a particular day or time. Certainly, there may be reasonable exceptions to such a definition if it could be established that a Veteran had been assigned to duties at the perimeter of the base or within mere feet of the perimeter of the base, but that is not the case here. As discussed below, the Board concludes that the weight of competent and credible evidence is against the Veteran having had regular duties on or near the perimeter of air bases in Thailand. The appellant contends that all the disabilities the subject of appeal, inclusive of COPD, prostate cancer, diabetes mellitus, peripheral neuropathy of the left and right hands and left and right feet, and ischemic heart disease, were due to the Veteran's exposure to Agent Orange in service. In contrast, during his lifetime the Veteran did not contend that he was exposed to Agent Orange in service. Rather, he claimed that COPD was due to respiratory infections in service, and that ischemic heart disease was due to hypertension. He died prior to being examined for his other claims the subject of appeal and never clarified the bases of those claims. The claim for service connection for hypertension was denied, and that denial is not the subject of appeal in substitution. Hence, the claim for service connection for ischemic heart disease cannot be supported on the theory of service connection as secondary to hypertension as a matter of law because hypertension is not service connected. 38 C.F.R. § 3.310. Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active military, naval, or air service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303 (a). Service connection may be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303 (d). Generally, service connection for a disability requires evidence of: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred in or aggravated by service. See Holton v. Shinseki, 557 F.3d 1363, 1366 (Fed. Cir. 2009). Diabetes mellitus, organic diseases of the nervous system, and cardiovascular diseases including ischemic heart disease are listed as "chronic diseases" under 38 C.F.R. § 3.309 (a); therefore, the presumptive service connection provisions based on "chronic" in-service symptoms and "continuous" post-service symptoms under 38 C.F.R. § 3.303 (b) apply. Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). For the showing of chronic disease in service, there is required a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time. With chronic disease as such in service, subsequent manifestations of the same chronic disease at any later date, however remote, are service connected, unless clearly attributable to intercurrent causes. If a condition noted during service is not shown to be chronic, then generally, a showing of continuity of symptoms after service is required for service connection. 38 C.F.R. § 3.303 (b). In addition, the law provides that, where a veteran served ninety days or more of active service, and certain chronic diseases, such as diabetes mellitus, ischemic heart disease, and organic diseases of the nervous system, become manifest to a degree of 10 percent or more within one year after the date of separation from such service, such disease shall be presumed to have been incurred in service, even though there is no evidence of such disease during the period of service. 38 U.S.C. §§ 1101, 1112, 1113, 1137; 38 C.F.R. §§ 3.307, 3.309(a). While the disease need not be diagnosed within the presumption period, it must be shown, by acceptable lay or medical evidence, that there were characteristic manifestations of the disease to the required degree during that time. Medical treatment records from years prior to his death establish that the Veteran was diagnosed with the claimed COPD, prostate cancer, diabetes mellitus, peripheral neuropathy affecting the hands and feet, and ischemic heart disease. The weight of the evidence is against the presence of COPD, prostate cancer, diabetes mellitus, peripheral neuropathy affecting the hands and feet, or ischemic heart disease in service or within the first post-service year and is against such diseases being present continuously since service. Service treatment records provide no findings of these conditions and none were found upon service separation examination. Medical records do not reflect a diagnosis of any of these conditions for years following service and provide no finding of onset of these disease processes in service or in years proximate to service. Hence, service connection is not supported for COPD, prostate cancer, diabetes mellitus, peripheral neuropathy affecting either hand or foot, or ischemic heart disease as directly related to service (with the preponderance of the evidence against) or based on presumptions for chronic disease (with evidence not supporting chronic symptoms from service or disability within the first post-service year). 38 C.F.R. §§ 3.303, 3.307, 3.309. A layperson is competent to report the symptoms that he experienced and his history of treatment. See Charles v. Principi, 16 Vet. App. 370, 374- 75 (2002). Further, under certain circumstances, lay statements may support a claim for service connection by supporting the occurrence of lay-observable events or the presence of disability or symptoms of disability susceptible of lay observation. Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009); Jandreau, 492 F.3d 1372 (holding that a layperson is competent to identify a simple condition such as a broken leg). However, lay competence does not extend to questions of medical causation which are not within the ambit of lay knowledge. Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007); Kahana v. Shinseki, 24 Vet. App. 428, 438 (2011). Thus, while the Veteran and appellant expressed a belief that the claimed COPD was related to respiratory infections in service and his other claim disabilities were related to service, the Veteran and the appellant, as lay people, lacked the medical knowledge and expertise required to address such questions of medical etiology which are beyond lay competence. The Veteran and the appellant have not been shown to have possessed the requisite expertise or knowledge to address these questions. Hence, their statements of this theory are not competent evidence to support the claim. In contrast, competent evidence has not been presented indicating any link between the Veteran's disabilities and his period of service. The focus of the appellant's claims, however, is service connection based on asserted herbicide agents (hereinafter also addressed simply as "Agent Orange") exposure during service, including based on service in Vietnam, duties at or near the perimeter of bases in Thailand, or otherwise based on Agent Orange exposure including when performing duties as an avionics instrument systems technician. To establish presumptive service connection for a disease associated with exposure to certain herbicide agents, the evidence must show the following: (1) that the veteran served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975 (or was otherwise exposed to an herbicide agent during active service); (2) that he currently suffers from a disease associated with exposure to certain herbicide agents listed under 38 C.F.R. § 3.309 (e); and (3) that the current disease process manifested to a degree of 10 percent or more within the specified time period prescribed in section 3.307(a)(6)(ii). 38 U.S.C. § 1116; 38 C.F.R. §§ 3.307 (a)(6), 3.309(e). If a veteran was exposed to an herbicide agent during active military, naval, or air service, then certain diseases shall be service-connected, if the requirements of 38 C.F.R. § 3.307 (a) are met, even if there is no record of such disease during service. VA's Compensation & Pension Service has issued information concerning the use of herbicides in Thailand during the Vietnam War and determined that special consideration of herbicide exposure on a factual basis should be extended to veterans whose duties placed them on or near the perimeters of Thailand military bases during the period beginning on January 9, 1962 and ending on May 8, 1975. VA Adjudication Manual, M21-1, Part IV, Subpart ii, Chapter 1, Section H.5. VA identifies several Royal Thai Air Force Bases (RTAFBs) in Thailand, including U-Tapao, Ubon, Nakhon Phanom, Udorn, Takhli, Korat, and Don Muang, and pursuant to the VA Adjudication Manual, herbicide exposure should be acknowledged on a facts found or direct basis if a United States Air Force veteran served at one of the RTAFBs as a security policeman, a security patrol dog handler, a member of a security police squadron, or otherwise served near the air base perimeter, as shown by evidence of daily work duties, performance evaluation reports, or other credible evidence. VA Adjudication Manual, M21-1, Part IV, Subpart ii, Chapter 1, Section H.5.b. During his lifetime, the Veteran did not submit any statement or testimony that he set foot in Vietnam or otherwise went on missions into Vietnam, and he did not contend that he had duties which placed him at the perimeter of bases while stationed in Thailand or that he was otherwise exposed to Agent Orange while stationed in Thailand or at any other time in service. Rather, only the appellant, the Veteran's surviving spouse, has made assertions of missions into Vietnam and of duties exposing the Veteran to Agent Orange while stationed in Thailand. She has asserted that he told her of missions and duties, and that these missions and duties had led him into Vietnam and had otherwise exposed him to Agent Orange. In a March 2014 statement, the appellant asserted that the Veteran was exposed to Agent Orange that remained on the airplanes while he was working on the airplanes. In a May 2014 submission, the appellant reported that during his service duties as an avionics instrument systems technician the Veteran had frequent temporary duty assignments (TDY), including one to Vietnam "to pick up bodies of U.S. servicemen." While the Veteran's service personnel records do reflect missions to or within Thailand including for training and for aircraft retrieval and maintenance, these records do not reflect travel to or duties in Vietnam. Review of the Veteran's service personnel records reveals that he was not merely an avionics instrument systems technician, but rather was a highly dedicated, experienced, and expert technician recognized in his service for his exceeding specialized skills and abilities, who received many commendations and promotions for his work, and who by the Vietnam Era had achieved senior level positions tasked with supervisory authority over many avionics repair technicians, as a trainer of other technicians and as a supervisor of shops and repair operations. The relevance of this high-level expertise and his senior-level positions are twofold: the Veteran's time was much in demand and his duties were highly specialized. The commendations repeatedly note the Veteran's tireless efforts in his field and his extreme level of dedication to his work. For all these reasons, it is doubtful that the Veteran would have been removed from his highly in-demand, specialized, expert, sought-after work within the service to be sent to Vietnam for duties removing bodies of fellow soldiers. There is no indication in the personnel records that the Veteran was ever tasked with such tasks. Similarly, at her hearing, the appellant asserted that the Veteran had been sent all over scavenging instrument panel parts from downed planes. Again, it is unlikely such an in-demand, specialize, expert, sought-after, highly dedicated professional would have been sent into Vietnam for such tasks. The personnel records do reflect special missions including secret missions, but as noted, they are now documented in the Veteran's personnel records and reflect only missions to Taiwan or Thailand or within Thailand, not missions to Vietnam. The appellant has asserted that the Veteran's military personnel records clearly show Vietnam service. However, while the Veteran's service personnel records contain duty records reflecting "Vietnam R" from May 29, 1969 to March 9, 1970, the Veteran's subsequent service personnel records inform that he was actually stationed at the Takhli Royal Thai Air Base, Thailand during that interval. Thus, "Vietnam R" may have represented Vietnam region, or may have been orders that were changed. Regardless, the service personnel records establish stationing in Thailand during that interval rather than Vietnam. There is a TDY in the Veteran's 201 file from April 23, 1969 to May 20, 1969, with the 4417 Combat Crew Training Squadron (CCTS) Instrument Section. Accordingly, an inquiry was sent to the U. S. Army and Joint Services Records Research Center (JSRCC) (formerly the U.S. Armed Service Center for Research of Unit Records (USASCRUR)). However, a reply from the Defense Personnel Records Information Retrieval System (DPRIS) in September 2014 informed that they had no record of a TDY of the 4417th CCTS into Vietnam during the January to June of 1969 interval. Hence, because none of the Veteran's service personnel records support such a TDY into Vietnam, this does not support the Veteran having set foot in Vietnam. Thus, service records do not support service in Vietnam or a TDY into Vietnam. Service records also do not support duties at or near the perimeter of bases while in Thailand. In a May 2018 submission, the appellant contended that the Veteran was exposed to Agent Orange in multiple ways while in service, including the following: while working near the perimeter at the Takhli air base; while sleeping, showering, and eating near the perimeter of that base, including due to open-air showers and windows being open; through participation in Operation Ranch Hand; and by the Veteran being in Vietnam for a short time, with tasks the Veteran performed in Vietnam including fixing an airplane, ensuring that an airplane was functioning, and escorting bodies. The Veteran served on active duty continuously from August 1954 to August 1977. By the time he was stationed in Thailand during the Vietnam War, he had reached supervisory ranks and would have been unlikely to be quartered with lower-level soldiers in primitive hooches at the periphery of bases as the appellant contends. A performance review for the Veteran's service period of observation from April 23, 1969 through April 20, 1969 records his rank as Staff Sergeant ("SSgt"), a Non-Commissioned Officer (NCO) rank. As noted above, pursuant to the VA Adjudication Manual, herbicide exposure should be acknowledged on a facts found or direct basis if a United States Air Force veteran served at one of the RTAFBs as a security policeman, a security patrol dog handler, a member of a security police squadron, or otherwise served near the air base perimeter, as shown by evidence of daily work duties, performance evaluation reports, or other credible evidence. VA Adjudication Manual, M21-1, Part IV, Subpart ii, Chapter 1, Section H.5.b. Thus, Air Force veterans with such regular duties placing them at the base perimeter where spraying occurred are to be distinguished from other Air Force Veterans who were merely stationed at one of the RTAFBs but had other duties not at the perimeter of the base. The May 2021 Joint Motion requires that the Board consider the appellant's statement in her May 2018 submission "that the Veteran was exposed to herbicides while working near the perimeter at multiple air bases in Thailand, to include while sleeping, showering, and eating near the perimeter of the base, including exposure due to open-air showers and sleeping in hooches with open windows." (Joint Motion, pg. 3.) The Board has duly considered the appellant's statement, and finds it unsupported by credible evidence and contrary to other evidence of record; and hence the Board finds that the appellant's statement is not credible evidence supporting the Veteran's exposure to herbicides in service. As noted, the Veteran's duties were in highly specialized avionics repair, avionics repair instruction, and avionics repair supervision. Such duties do no imply work at the perimeter of Air Force bases, such as would a security policeman, security patrol dog handler, or member of the security police squadron, or other personnel who would generally work at the perimeter of the Air Force bases. If showering, eating, and sleeping were to be evidence of such work at the perimeter of Air Force bases as to support exposure to herbicides by regular duties at the perimeter of Air Force bases, then certainly all personnel at RTAFBs would qualify, since all stationed at the bases presumably regularly showered, ate, and slept. The appellant's supposition that the Veteran's duties at the RTAFBs caused him to shower, eat, and sleep in places and manners that caused him to be exposed to herbicide agents, in contrast to other Air Force veterans who did not otherwise have perimeter duties, is not supported by the personnel record. The Board has discounted the appellant's assertions of the Veteran having gone on missions into Vietnam either for retrieval of dead bodies or for scavenging of aircraft parts as not supported by the record and not credibly consistent with the nature of the Veteran's highly specialized and in-demand work as a high-level avionics specialist, as already discussed. Based on her other non-credible assertions, and absent evidence corroborating these other assertions and absent evidence corroborating her assertions of the Veteran having regularly showered, eaten, and slept by the perimeter of bases as well as in open-air hooches near the perimeter of bases, the Board find all of these assertions by the appellant to be not credible and not supported by evidence of record, with the preponderance of the evidence, inclusive of the nature of the Veteran's highly specialized duties and higher rank during the Vietnam War, against her assertions. The Board must analyze the credibility and probative value of the evidence, account for the evidence that it finds persuasive or unpersuasive, and provide the reasons for its rejection of any material evidence favorable to the claimant. Kahana v. Shinseki, 24 Vet. App. 428, 433 (2011). This includes weighing the credibility and probative value of lay evidence against the remaining evidence of record. See King v. Shinseki, 700 F.3d 1339 (Fed. Cir. 2012); Kahana, 24 Vet. App. at 433-34. In determining the weight to be assigned to evidence, credibility can be affected by inconsistent statements, internal inconsistency of statements, inconsistency with other evidence of record, facial implausibility, bad character, interest, bias, self- interest, malingering, desire for monetary gain, and witness demeanor. Caluza v. Brown, 7 Vet. App. 498, 511, 512 (1995), aff'd per curiam, 78 F.3d. 604 (Fed. Cir. 1996). The Board finds the appellant's assertions of the Veteran's exposure to herbicide agents while stationed at RTAFBs in Thailand including in the course of showering, eating, and sleeping near the perimeter of these bases including in open-air hooches, not to be credible based on their facial implausibility, inconsistency with evidence of record concerning the Veteran's rank and duties in service, and based the appellant's other statements of record concerning missions into Vietnam also not being credible. Because the Board finds that these statements by the appellant are not credible evidence supporting the Veteran having regular activities or duties at the perimeter of RTAFBs, and other evidence of record also does not support the Veteran having regular activities or duties at the perimeter of RTAFBs, the Board concludes that the preponderance of the evidence is against the Veteran having been exposed to herbicides on such bases. Rather, the Board concludes that based on his higher rank and highly specialized duties in avionics repair, instruction, and supervision (as evidence by numerous evaluation reports contained within his personnel records), the Veteran was rather likely to have been one of the least likely Air Force personnel to have had regular activities or duties at the perimeter of RTAFBs, since the Air Force would be highly unlikely to take a highly specialized, capable, and in-demand senior, supervisory technician who worked on, supervised work on, and instructed work on crucial and complex avionics parts of aircraft and place that technician at the perimeter of a base to perform that work, supervision, and instruction, where such highly valuable personnel and equipment would be least protected and most likely to be at risk of harm by hostile forces. The Board notes that the perimeter of bases, with its perimeter boundaries and guards, etcetera, are precisely to protect the personnel and equipment of the base, and hence having among the most senior, valued, and technically expert technical personnel regularly perform work on highly valuable equipment at the perimeter of the base is simply not plausible. It is also not plausible that the Veteran, as a Staff Sergeant with the above-noted duties, would have been assigned to guard duty at the perimeter of bases while in Thailand. The Board accordingly concludes that it is not plausible and not supported by credible evidence that the Veteran had regular duties or assignments or regular activities placing him at the perimeter of bases in Thailand, and hence his exposure to herbicides by such means is also not plausible. The appellant has also submitted copies of favorable decisions of the Board of Veterans' Appeals (Board) in other Veterans' cases. The appellant asserts that these other cases involved other veterans being exposed to Agent Orange, with evidence relied on in those cases including pictures of bases where exposures occurred and information about duties of those other Veterans. However, decisions by the Board are not precedential, and the Board's decision for each case is fact-specific and may be subject to variance in its application of specific law based on facts and circumstances unique to an individual case. See 38 C.F.R. § 20.1303; Hudgens v. Gibson, 26 Vet. App. 558, 566 (2014). The Board is thus not required to be consistent in its decision-making. Id. The Board does not here consider these submitted other Board decisions pertaining to other claimants to be probative for purposes of the Board's adjudication of the appellant's claims, since these other decisions were made in the context of other evidence and circumstances of which the undersigned cannot be fully aware, not having reviewed the files of those other veterans. The Board finds that the preponderance of evidence presented is against the likelihood that the Veteran was stationed in Vietnam, had missions in Vietnam, or otherwise set foot in Vietnam, and is also against the Veteran having duties at or near the perimeter of bases when stationed in Thailand. The record contains no indication that aviation instrumentation repair facilities at which the Veteran worked were located at or near the perimeter of military bases. The appellant has presented no credible evidence supporting a likelihood that the Veteran's duties as an avionics systems technician or as a supervisor took him into Vietnam, or supporting these duties being at or near the perimeter of a base in Thailand. In light of the considerable body of service treatment and service personnel records documenting the Veteran's stations and missions while in service, with none of these supporting the appellant's assertions of duties exposing the Veteran to Agent Orange or missions sending him into Vietnam, and in light of the highly valued and specialized work of the Veteran while in service most likely effectively precluding him from missions into Vietnam to pick up bodies of fallen soldiers (as the appellant has alleged), the Board finds that the preponderance of the evidence is against the likelihood of such missions into Vietnam or duties at or near the perimeter of bases in Thailand. While the appellant is competent to testify to what she may have been told by her spouse, the Veteran, about actions or missions in service, such statement may have been told in other contexts for other purposes, and hence may not be reliable accounts of actions of the Veteran. The Board finds more probative the countervailing service personnel records and service treatment records which do not place the Veteran in Vietnam and do not support perimeter duties while the Veteran was in Thailand. The Board must now address the question of whether service connection for claimed conditions is warranted presumptively based on Agent Orange exposure based on the Veteran having worked on C-123 aircraft. The relevant regulation, in pertinent part, states that Agent Orange exposure is presumed for [a]n individual who performed service in the Air Force or Air Force Reserve under circumstances in which the individual concerned regularly and repeatedly operated, maintained, or served onboard C-123 aircraft known to have been used to spray an herbicide agent during the Vietnam era shall be presumed to have been exposed during such service to an herbicide agent. For purposes of this paragraph, "regularly and repeatedly operated, maintained, or served onboard C-123 aircraft" means that the individual was assigned to an Air Force or Air Force Reserve squadron when the squadron was permanently assigned one of the affected aircraft and the individual had an Air Force Specialty Code indicating duties as a flight, ground maintenance, or medical crew member on such aircraft. Such exposure constitutes an injury under 38 U.S.C. § 101 (24) (B) and (C). If an individual described in this paragraph develops a disease listed in 38 C.F.R. § 3.309(e) as specified in paragraph (a)(6)(ii) of this section, it will be presumed that the individual concerned became disabled during that service for purposes of establishing that the individual served in the active military, naval, or air service. 38 C.F.R. § 3.307(a)(6)(v). While the appellant in her March 2018 testimony did not then report having any specific knowledge of the Veteran having worked on C-123 aircraft, including any such aircraft used to spray Agent Orange, she did reference the existence of regulations allowing for service connection for presumptive conditions on that basis, and she testified to the fact that the Veteran did work on aircraft generally in the Vietnam War. She also referenced submitted reports about military operations including Operation Ranch Hand. See Hearing Transcript, pages 5, 9. In its November 2019 decision, the CAVC characterized the appellant's testimony as asserting that the Veteran was exposed to herbicides while working on C-123 aircraft. The appellant did not say this, but this distinction is immaterial, since her testimony amounted to no more than argument because the appellant did not testify to having any personal knowledge, based on the Veteran's statements to her or otherwise, of the Veteran working on C-123 aircraft in service. The appellant has not articulated having knowledge, through conversations with the Veteran during his lifetime, through conversations with others, or through any written statements about the Veteran or his service activities, of the Veteran having worked on C-123 aircraft, or of her having other proofs of his having performed such work, other than based on service documents which have been associated with the electronic claims file and reports more generally about operations that were performed in Vietnam. The record contains no specific information in any such military operations reports which identify the Veteran or one of his units as having worked on C-123 aircraft. Hence, the Board must base its analysis on review of the Veteran's service personnel records to discern the likelihood that the Veteran regularly and repeatedly operated, maintained, or served aboard C-123 aircraft known to have been used to spray Agent Orange, as is required for presumptive service connection pursuant to 38 C.F.R. § 3.307(a)(6)(v). The claims file contains multiple copies of the Veteran's voluminous service personnel records. These personnel records inform of the Veteran's long and illustrious career performing work on aircraft, instructing on the performance of work on aircraft, and supervising and commanding crews performing work on aircraft, including both on the aircraft themselves and in repair shops performing work on aircraft parts and systems, as well as performing work on machinery used in the repair or testing or calibration or maintenance of aircraft. These records include reviews of the Veteran's work over intervals and include numerous detailed commendations for his exemplary performance and the quality of his work and the work of his crews. These records inform that his specialty was in aircraft instruments and avionics, and he progressed through the ranks to increasing levels of authority, from repairman to specialist to instructor and supervisor to technical sergeant. He completed many specialized trainings and was recognized in the service as a remarkably qualified and capable technical specialist in his areas of expertise. However, the Veteran's work and expertise, being of a technical nature, was necessarily not universal, and it cannot be assumed that he worked on every kind of aircraft on every type of instrumentation or avionics system, even though his personnel records do inform that he worked on several specific systems. His personnel records inform that he worked on instrumentation or avionics systems (or instructed or supervised the work of other soldiers on these systems) of the B-66, K-135, B-52/K-135, F-105, EB-66, F-101 B/F, T-33, C-130E, and Aircraft 032. These fighter aircraft and other aircraft necessarily contain particularized instrumentation and avionics systems of which the Veteran had to gain mastery. These notably did not comprise every aircraft within the fleets of those used in the Vietnam War, just as they also did not comprise any helicopters, Jeeps or other land vehicles, or any watercraft. The Veteran's service personnel records quite clearly document that the Veteran was a technical specialist, and while he had achieved such technical expertise for a number of aircraft, nowhere do his service personnel records inform of his having completed training for the instrumentation or avionics systems of C-123 aircraft, and nowhere do his service personnel records inform of his having performed work on C-123 aircraft, instructed on work on C-123 aircraft, or supervised work on C-123 aircraft. This is in contrast to service personnel records which do clearly document, including in performance reports and statements of commendation, his work with the above-listed other aircraft. Hence, the Board concludes based on careful review of the record, including in particular careful review of the Veteran's service personnel records, that it is highly unlikely that the Veteran regularly or repeatedly performed work on C-123 aircraft during service, with the preponderance of the evidence against this, precisely because if he had done so it would have found some mention in his service personnel records which are careful to note the aircraft on which he did work and for which he did gain technical mastery. The Board accordingly concludes that the preponderance of the evidence is against the Veteran having regularly and repeatedly operated, maintained, or served aboard C-123 aircraft known to have been used to spray Agent Orange, as is required for presumptive service connection pursuant to 38 C.F.R. § 3.307(a)(6)(v). Accordingly, the Board concludes that (Continued next page) service connection for the claimed conditions on a presumptive basis based on presumptions available under 38 C.F.R. § 3.307(a)(6)(v) is not warranted. L. CHU Veterans Law Judge Board of Veterans' Appeals Attorney for the Board D. Schechter The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.