FSB Reports and Differences Training Levels

A Flight Standardization Board (FSB) report answers a practical question that every airline with more than one model faces: when a pilot is qualified on one aircraft, what does it take to fly its relative? The report names the pilot type rating, sets the minimum training, checking and currency for the type, and grades each difference between related models on a scale from Level A, a handout, to Level E, a Level C or D full flight simulator or the aircraft itself.

Those answers shape fleets and careers. Because the FSB gives every Boeing 737 from the -100 to the MAX the single rating B-737, an NG first officer moves to the MAX through a differences course rather than a new type rating. Because the draft of the next A320 report grades the move from the A330 to the A320 at Level E, a widebody pilot converting to the narrowbody trains in a Level C or D full flight simulator or the aircraft. Europe reaches comparable decisions through its operational suitability data, covered at the end of this article.

The Flight Standardization Board

FSBs are formed within the FAA's Aircraft Evaluation Division (AED), called the Aircraft Evaluation Groups (AEG) in older reports. The division works with manufacturers and modifiers while a new or modified aircraft is developed and certified, and it determines three things: the pilot type rating; the flight crew's training, checking and currency requirements; and the aircraft's operational suitability, meaning that it may be used in the National Airspace System and meets the operating rules, such as Parts 91, 121 and 135.

Its readers are the FAA inspectors who approve training programs, the inspectors and designees who certify pilots, and the operators and training centers that build courses on it.

The board works by evaluation, following FAA Advisory Circular 120-53, whose Revision B of 2013 was replaced on 11 September 2025 by AC 120-53C, Flight Standardization Board Evaluations. Its evaluations are numbered tests, as the 737 report shows: in 2016 the board ran a T2, a handling qualities comparison, and a T3, an evaluation of the proposed 737-800 to 737-8 differences course; in 2017 it ran a T5 on the initial 737-8 type rating course and a T1, a functional equivalence test, from the 737-8 to the 737-9.

Reports are living documents. The 737 report reached Revision 17 in November 2020, with the MAX's return to service, and Revision 20 in May 2026; a Revision 21 draft adds the 737-7. The FAA posts draft revisions on its website, and operators train to the revision in force. The FAA's A320 figures here come from the draft of Revision 7, which adds the A321XLR and is to replace Revision 6 of April 2019.

What an FSB report contains

Reports in the FAA's current format share one layout. After acronyms and definitions come sections on the pilot type rating, related aircraft, pilot training, pilot checking, pilot currency, operational suitability and miscellaneous items. The appendices hold the differences legend, the master differences requirements (MDR) table and the detailed differences tables, followed by type-specific material; the 737 report adds supervised line flying, head-up guidance training, alternate go-around flaps and the special 737 MAX training.

The training and checking sections use a fixed set of terms:

The miscellaneous section records operational facts the FAA has evaluated: the aircraft approach category (C for the A318, A319 and A320, C or D for the A321 depending on its maximum landing weight), the normal landing flap settings, where to find ETOPS suitability and the suitability of the observer seat.

Type rating designations

Each report gives the pilot type rating designation entered on a US pilot certificate:

• B-737 for every 737, from the 737-100 to the 737 MAX.
• A-320 for the A318, A319, A320 and A321, ceo and neo.
• BD500 for the A220-100 and A220-300, the designation Transport Canada also uses; it did not change when the CS100 and CS300 were renamed.
• B-787 for the 787-8, 787-9 and 787-10.

A shared rating does not let pilots move between models freely. It means the move is handled by differences training within one rating rather than by a new type rating course with a skill test (see class and type ratings).

Related aircraft and common type ratings

The reports define related aircraft as two or more aircraft of the same make, on the same or different type certificates, that the FAA has found to have commonality. Related aircraft on one type certificate data sheet are the usual case: every 737 is on data sheet A16WE, in four series groups (the original 737, the Classic, the NG and the MAX), and the A318 to A321 share A28NM (see type certificate data sheets).

Related aircraft on different data sheets are rarer. The A320 report, in its Revision 7 draft, lists the A330 and A340 as related to the A320, so their pilots can convert through related aircraft differences training, and the A350 as related for currency only, because no training evaluation had been completed. Under the draft, a pilot converting from the A330 or A340 must be qualified and current on that type and, unless other experience is approved, have at least 300 hours of line experience on it as pilot in command or second in command.

A common type rating goes one step further: two separate type ratings, on different type certificates, with enough commonality for a pilot holding one to add the other through a validated differences course and check. The 777 and 787 are the example. In 2011 the FAA announced that its 787 FSB had found the two airplanes to qualify for a common type rating and had validated Boeing's 777-to-787 differences course; no 787-to-777 course existed yet, and a B-777 holder still needed that training and checking to add the B-787. Revision 7 of the 787 report (2019) keeps B-787 and B-777 as separate ratings with commonality and grades the differences between them at Level D. The 737 and A320 reports list common type ratings as not applicable. EASA instead puts both airplanes under one rating, B777/787.

Differences levels A to E

Each difference between a base aircraft and a related aircraft gets a training level and a checking level. Appendix 1 of the 737 and A320 reports defines the scale:

The levels are applied item by item in the differences tables, which the manufacturer proposes and the FSB validates. Each row names a design feature or a maneuver, records whether it changes flight characteristics or procedures, and gives the minimum training and checking levels that, in the reports' own words, operators "must use". From the 737-800 to the 737-8, for example, the 8 in longer nose gear is A/A, the new display system and the LEAP-1B engines are B/B, and the demonstration of MCAS activation is E*/A, the asterisk pointing to the special training of Appendix 7.

Checking and currency levels

Checking has its own scale. Level A checking means no check when the differences training is done, although the differences can and should feature in later proficiency checks. Level B is an oral or written exam or a CBT self-test. Levels C, D and E use the same classes of device as the matching training levels, up to a Level C or D simulator or the aircraft.

Currency has its own section. The 737 report adds nothing to the recent experience rules of Parts 61, 121, 125 and 135, and its later revisions accept Level B differences training for currency between the NG and the MAX once a pilot has completed the initial E* training. The A320 report treats its four models as one: meeting the currency requirements in any of them satisfies all.

Mixed fleet flying, operating a base aircraft and related aircraft together with credit for training, checking and currency, has its own rules. For pilots flying both the A320 and the A330, the Revision 7 draft of the A320 report requires, every 90 days, three takeoffs and three landings as pilot flying, at least one landing flown manually in each type, and one line segment in each. Between the 737 series groups the FSB recommends alternating the proficiency check, every 6 months for captains and annually for other pilots. The 737 report also sets supervised line flying between series: none between the NG and the MAX, but "2/5", at least 5 hours including two flight segments, between older series such as the original 737 and the Classic.

Master differences requirements

The MDR table condenses the differences tables into one entry for each pair of related aircraft, the minimum training and checking for the whole move, taken from the highest level among its items. Direction matters, because the levels from base to related aircraft and back can differ. An excerpt from the 737 report:

The E* flags Appendix 7, which every pilot must complete before operating the MAX: ground training through Boeing's 737 MAX CBT or an FAA-approved equivalent, and five simulator exercises, among them an MCAS activation demonstration, flown in a 737 MAX Level C or D simulator, with an NG simulator accepted for the two manual trim exercises.

The A320 table of the Revision 7 draft is simpler. Between any two of the A318, A319, A320 and A321 the minimum is B/A; a move to the A321neo ACF or the A321XLR carries B/B; the A330 or A340 to the A320 is E/E; and the A350 is not evaluated.

Operators then show how their own courses meet these minimums. The 2003 JAA evaluation of the A320 family calls the operator's version operator differences requirements (ODR) tables, and it required approved ODR tables from every operator of more than one variant.

Examples: A320 family, 737, A220 and 787

A320 family. The FSB requires differences training between the four models and between different engine makes and models, so a pilot moving between CFM and Pratt & Whitney powered A320neos takes a course although the rating is unchanged. The Revision 7 draft prints no ceo-to-neo table, so that content comes from the operator's approved course (A320neo and A320ceo differences). Its special emphasis list includes the XLR's control law reconfigurations, which follow from deleting the flight augmentation computers and the third spoiler elevator computer and fitting an electrical rudder.

737. The MAX kept the 737 rating, but since the 2019 to 2020 grounding the conversion carries the Appendix 7 training on top of the Level B differences course (737 NG and MAX differences). Unreliable airspeed with an erroneous high angle of attack joins the stabilizer trim items as a special emphasis area, repeated at least once every 36 months.

A220. The two models differ mainly in length, weights and capacity. The FAA sets Level B differences training between them; Transport Canada, the authority that certified the type, sets Level A, a pilot differences handout, with no check, and accepts currency on either model for the other (see A220 family and limitations).

787. Moving between the three models takes Level A differences training, by self-instruction, with no differences checking or currency. In a fleet that mixes 777s and 787s, the report has proficiency checks alternate between the two types and may allow takeoff and landing credit from one to the other (787 family and flight deck).

The European equivalent: operational suitability data

EASA built operational evaluation into certification with Regulation (EU) No 69/2014, in force from 18 February 2014. Type certificates now carry operational suitability data (OSD), whose flight crew part, approved against the certification specification CS-FCD, sets the minimum type rating syllabus and the differences between variants. Evaluation reports issued earlier by the JAA or EASA, called operational evaluation board reports, were deemed to be OSD. EASA's type rating and license endorsement list shows which aircraft share a rating and points to the data behind it.

The European scale is a close relative of the FAA's. The 2003 JAA report on the A320 family, evaluated by FAA, Transport Canada and JAA pilots and following both the JAA handbook and AC 120-53, uses the same levels with a third letter for currency: B/A/A between the four models, where Level A currency means that recent experience on any variant counts for all. The words differ at the edges: the conversion to the A318 that the FAA and Transport Canada call differences training appears in that report as familiarization training.

Library articles are written for study and exam preparation. They do not replace your aircraft's approved documentation, your operator's procedures or the regulations themselves.