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The TIGHAR Guide to
Aviation Historic Preservation Terminology

This Guide presents terminology and definitions assembled by TIGHAR from sources in the United States, Great Britain, the Netherlands, and Australia. The foundation is especially grateful to David Hallam (TIGHAR #0912C), Senior Conservator at the National Museum of Australia, Canberra, for his help in assembling the pioneering work done on this subject in his country.

Special thanks also to:

  • Tom D. Crouch, Chairman of Aeronautics, National Air & Space Museum, Smithsonian Institution, Washington, D.C., USA.
  • Michael Fopp, Director, The Royal Air Force Museum, Hendon, London, Great Britain.
  • David Lee, Assistant Director, The Imperial War Museum, Duxford, Great Britain.
  • Stephen Grey, The Fighter Collection, Duxford, Great Britain.
  • Jack Hilliard, Curator, United States Air Force Museum, Wright-Patterson Air Force Base, Ohio, USA (retired 1993).

The most important thing to understand about the language used to describe historic aircraft and their management is that it is no different from that used to describe other historic preservation disciplines. While there are a handful of terms unique to aviation (such as airworthy), most of the definitions in this Guide come directly from related fields, such as industrial and maritime historic preservation, and are the result of years of scholarly consideration and debate. Regrettably, a long period of self-imposed isolation has, until now, made aviation historical language a Tower of Babel, with each air museum and collection devising whatever definitions make its own aircraft look best. It is hardly surprising, therefore, that when standardized, rigorous and well-thought-out terminology is applied to the world's collections, we find some surprises.

For example: Old boats and old airplanes are two sides of the same preservation coin, but maritime historic preservation is many years ahead of aviation in defining its terms and its artifacts. In July of 1990, the U. S. National Park Service published the result of a five year study entitled The Secretary of the Interior’s Standards for Historic Vessel Preservation Projects. Among its findings is that rehabilitation, defined as “returning the vessel to a state of utility through repair or alterations,” is the choice of last resort. And yet many in aviation have, for years, considered an historic aircraft’s return to airworthy condition to be the most desirable objective. Most of the contents of the world’s air museums, and virtually all vintage airplanes flying today, should be properly termed reconstructions rather than restorations. And yet, that same NPS report specifically notes that “replicas, reproductions, and reconstructions are not historic vessels.”

Describing Rare Aircraft

Determine the most accurate nomenclature for the specific aircraft you wish to describe. Include the manufacturer, model number or military designation, variant or mark designation, popular name (if any), and its individual civilian or military registration and name (if any). Examples:

  • Boeing B-17G Flying Fortress 42-32076 “Shoo Shoo Shoo Baby”
  • Ryan NYP NX211 “Spirit of St. Louis”

Find the noun which most accurately describes the aircraft as it exists now. The possibilities below are listed in descending order of desirability. Naturally, when more than one term applies the least desirable description must be used. Note: Use of the terms original, restoration, and reconstruction must include a reference date (for example, original to 1947).



Modify the description with adjectives which provide further information about the aircraft.


Fourth Where applicable, complete the description with the date, in the case of originals, restorations and reconstructions; or, in the case of rehabilitations, reproductions, adaptations and replicas, specify whether the aircraft is represented in factory or service condition.


“Shoo Shoo Shoo Baby,” now on display at the United States Air Force Museum, was damaged on a raid over Germany during World War II and landed in Sweden. The aircraft was interned and later extensively modifed for a number of post-war uses by various owners in Scandinavia and France. In 1972 it arrived at Wright-Patterson AFB, Ohio, in boxes, having been cut up for shipment with chain saws. Moved to Dover AFB, Delaware, the aircraft underwent an extensive rebuild which included the replacement of many major components with parts from other B-17s, and, in some cases, newly fabricated parts. Although the USAF Museum does not generally fly aircraft in its collection, the only practical, and ultimately the safest, way to deliver “Shoo Shoo Shoo Baby” to Ohio was to fly it there. The aircraft was therefore rebuilt to airworthy condition and flown to the United States Air Force Museum in 1988. The aircraft is not an original nor is it a restoration. It is correctly described as:

Boeing B-17G Flying Fortress
#42-32076 “Shoo Shoo Shoo Baby”
a composite rehabilitation to factory condition.


The “Spirit of St. Louis” was delivered to the Smithsonian Institution in 1928 at the conclusion of Lindbergh’s extensive public relations tour which followed his triumphal return from France the previous year. During that time, routine maintenance and repair work replaced much of the material which had been part of the airplane when it made its Atlantic crossing. However, once accessioned into the Smithsonian collection, the aircraft was conserved rather than subjected to more radical treatment. Today the aircraft is correctly described as:

Ryan NYP NX211 “Spirit of St. Louis,” a preserved,
definitive original, reference date 1928.

Important Considerations
Many of the terms in this Guide will be familiar to aviation professionals and enthusiasts, while others will be less so. Some of the words, such as repair, fabric, and maintenance, mean something very different when used in an historic preservation context than they do when they are used during an aircraft’s active service (just as irrigation means something very different to a physician than it does to a farmer).
Rare vs. Historic
This is a very important distinction and one which is commonly misunderstood. The criteria for judging historical significance are listed under the term's definition, but the decision as to whether a particular machine is an historic aircraft or merely a rare aircraft will depend, in large part, upon its historical integrity. Because historical integrity is determined by how much of the aircraft's original fabric survives, we must accept the fact that aircraft routinely assumed to be historic do not qualify for that special appellation. However, it also means that concerns about the destruction of historic aircraft in flying accidents should, more accurately, be aimed at preventing the loss of rare aircraft because, by definition, an aircraft rehabilitated to airworthy condition is no longer an historic aircraft.

Hierarchy of Desirability:

Historic Aircraft


Rare Aircraft


Decisions regarding the treatment and management of any particular aircraft must balance the need to safeguard its original fabric against the desire to present an attractive and meaningful object for public exhibition.



Modification of an object to serve a new compatible use.


Capable of meeting current regulatory standards for flight.


Any object made by human work.

Compatible Use.

A use which involves no change to the historically important features of an object.

Condition, Factory.

The condition an object was in when it left the manufacturer.

Condition, Service.

The condition an object was in at a particular time in its economic life.


All the processes of looking after an object so as to retain its culturally significant qualities, and minimize deterioration.

Conservation, Display.

Treatment of an object to arrest deterioration, prevent further deterioration, and, at the same time, provide for cosmetic display considerations.

Conservation, Emergency.

Stabilization of an object in need of immediate measures to arrest and prevent rapid deterioration.

Conservation, Preventive.

Long-term care of an object by measures designed to prevent deterioration and damage.

Conservation, Project.

Progressive treatment of groups of similar objects.


An object that has been altered to effect a representation of or resemblance to another object.

Economic Life.

That period of an object’s life during which it is in active service, whether performing its originally intended function, or some later useful adaptation.


All the physical material of an object.


Capable of flight. Note: not the same as airworthy.

Generic Example.

Means the same as representative object. An object which has no individual historical or cultural significance other than as a surviving example of its type.

Historic Aircraft.

An aircraft which retains a meaningful degree of historical significance. See historic property.

Historical Significance.

An object’s æsthetic, scientific, technological, and social merit assessed in terms of its:
  • condition and extent of remaining original material.
  • association with a particular historic event or individual.
  • rarity as a survivor of its type.
  • evidence of past design innovation, style, construction techniques, etc.
  • political, cultural or spiritual significance to a particular segment of society.
  • exceptional æsthetic qualities of form or decoration.
Integrity, Historical. The degree to which an object retains its fabric and identity.
Integrity, Structural. The degree to which an object retains its physical composition.
Interpretation. The cultural message communicated by the treatment and management of an object.
Maintenance. The continuous care of an object without alteration of its fabric.
  1. (Latin, a place of study) A building, or part of one, in which are preserved and exhibited objects of permanent interest in one or more arts and sciences. [Webster’s Second International Unabridged Dictionary]
  2. An institution that collects, studies, exhibits, and conserves objects for cultural and educational purposes. [Encyclopedia Britannica]
Object. Means the same as property. Any physical entity considered for treatment or management.
Object, Composite. A representative object built up from pieces and components from others of its type.
Object, Definitive. An irreplaceable object of great historical and/or cultural significance.
Object, Representative. Means the same as generic example. An object which has no individual historical or cultural significance other than as a surviving example of its type.
Object, Working. An object whose purpose is to provide a functioning example of its type. In the working object, repair has priority over preservation and historical integrity is thereby sacrificed.
Original. The actual fabric that is passed down from a particular time in history.
Preservation. Maintaining the fabric of an object in its existing state and halting deterioration.
Rare Aircraft. An aircraft of a type of which relatively few examples exist. Not necessarily an historic aircraft.
Reconstruction. Returning an object to a known earlier state by means of repair of the existing fabric and, to a substantial degree, its replacement with new materials.
Recovery. The removal of an object from surroundings detrimental to its conservation.
Rehabilitation. Return of an object to a state of utility through repair, reconstruction, and often adaptation or conversion.
Repair. Means the same as restoration. Returning the existing materials of an object to a known earlier state with minimal introduction of new material.
An object constructed to represent, to a greater or lesser degree of accuracy, an object which existed at some previous time.
Reproduction. A copy of an existing object.
Restoration. Means the same as repair. Returning the existing fabric of an object to a known earlier state with minimal introduction of new material.
Reversible. Capable of being undone with no adverse effect to the original fabric of the object.
Stabilization. The short-term arresting of deterioration pending the implementation of further conservation measures.

The point of all historic preservation is the safeguarding of the physical material passed down to us from the past.

The TIGHAR Guide to Aviation Historic Preservation Terminology makes available to the aviation world the language it needs to truly save the relics of its heritage. A PDF may be downloaded for printing HERE. It is free.

For a 65 page transcript of in-depth discussions on the principles of aviation historic preservation, copies of Proceedings: Aircraft to Artifact, An International TIGHAR Seminar are available. Held at the Royal Air Force Museum in London, September 1990, this first-of-its-kind event brought together directors and representatives of ten air museums from eight countries. It will be available shortly as a PDF in the TIGHAR Store.

The TIGHAR Guide To Aviation Historic Preservation Terminology is a publication of The International Group for Historic Aircraft Recovery, a non-profit foundation. The terms and definitions presented here, while gathered from the most authoritative sources, were selected and edited by TIGHAR. TIGHAR is solely responsible for this publication.

© TIGHAR 1991
All Rights Reserved
Second Revised Edition © 1992
Third Revised Edition © 1993
Fourth Revised Edition ©2017

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