Beginner's Guide

Space Available ("Space-A") travel is a benefit that lets eligible military members, retirees, and their families fly on US military aircraft when there are empty seats left after official passengers and cargo are loaded. It is managed by Air Mobility Command (AMC) and operates out of passenger terminals at military bases worldwide.

Flights are typically free or very low cost, but there are no guarantees. Schedules change constantly, seats open and close with little warning, and travelers must be flexible. Think of Space-A as standby travel with extra paperwork — when it works, it's an incredible perk. When it doesn't, you need a backup plan.

Eligibility is defined by DoDI 4515.13, Table 3, which assigns every traveler to one of six priority categories. Within a category, position is determined by sign-up date and time. Higher categories always board first — Cat I has the highest priority, Cat VI the lowest. Table 3 lists 48 specific traveler types; the categories below cover the common cases.

Common required documentation across all categories: DoD ID card (CAC, retiree, or dependent ID), passport for overseas travel, and any category-specific paperwork (leave orders, EML authorization, MOH certificate, sponsor's command authorization for unaccompanied dependents). See the next section for the policy overview.

Full eligibility list (all 48 Table 3 items and restrictions per geographic segment): DoDI 4515.13 (PDF).

DoDI 4515.13 (“Air Transportation Eligibility”) is the Department of War policy that governs every passenger movement on DoW aircraft, including Space-Available travel. It was originally issued 22 January 2016, and the version currently in force — Change 7 — was approved 11 January 2024. AMC, every passenger service agent, and every traveler operates under these rules.

The policy covers seven types of air transport. Space-A is one chapter within a larger document:

• Section 3 — Space-Required: duty and mission travel; takes priority over everything else on the aircraft.
• Section 4 — Space-Available: the recreational program described on this page. Includes baggage rules, sign-up procedures, documentation, and the Cat I–VI priority table.
• Section 5 — Medical patients: aeromedical evacuation and outpatient travel; mostly Cat VI.
• Section 6 — Cargo: separate eligibility, not Space-A.
• Section 7 — Human remains: dignified transfer and escort travel.
• Section 8 — Orientation flights and Public Affairs: discretionary command-level access.
• Section 9 — Foreign governments and international organizations: exchange officers, foreign cadets, etc.
• Section 10 — Service animals, pets, and other animals: detailed rules; the kennel and ESA policy you'll see on AMC pet pages traces here.

The Space-A details on this page cross-reference DoDI 4515.13 throughout. Highlights of what Section 4 establishes:

• The 6 priority categories (Cat I–VI) and the 48 specific traveler types in Table 3. See Who Can Fly Space-A? for the breakdown.
• Sign-up windows: register up to 60 days before travel; remain active for 60 days. Position within category is determined by sign-up date and time. See How to Sign Up.
• Baggage allowance: two checked bags up to 70 lbs and 62 linear inches each, plus a 45-linear-inch hand-carry. Family allowances combine. See What to Bring.
• Documentation requirements: a valid DoD ID card is universal; passports are required for most overseas travel; leave orders required for active-duty leave travel; sponsor authorization required for unaccompanied dependent travel.
• Minors: dependents under 18 traveling unaccompanied need written sponsor authorization. Dependents under 14 must travel with a parent or legal guardian and carry their own Federal/State/local/tribal ID (a hospital certificate of birth is not accepted).
• EML travel: Environmental Morale Leave is restricted to specific designated locations per Service; sponsor and dependents must hold valid EML authorization documents.
• Travel restrictions for Cat VI Reserve retirees and 100% DAVs: limited to U.S. domestic and named possessions; international travel not authorized (see the warning above).
• Bumping rules: once accepted for movement, Space-A passengers are not bumped except for Cat I emergency or higher operational priority.

Read the full policy: DoDI 4515.13, Change 7 (PDF, 78 pages). Section 4 (Space-A) starts on page 28; Section 10 (animals) on page 56.

Where DoDI 4515.13 sets eligibility, DAFI 24-605V2 (“Air Transportation Operations,” 30 January 2025) is the Department of the Air Force's operational rulebook for how passenger service agents (PSAs) actually run a Space-A terminal. It's the regulation you bump into when you wonder why a flight lists only 19 seats, when roll-call timing is fixed, how head tax vs FIS fees are split, or what happens when a flight diverts. Most of the rules below come from Chapter 2 (Passenger and Fleet Operations) and Chapter 4 (Mission Operations).

• Sign-up timestamps are Zulu (GMT) (§ 2.25.4). The clock time stamped on your sign-up confirmation is GMT, not local — this affects how your position is ranked against other travelers at the same terminal who signed up the same calendar day.
• Family groups can register together; non-family must register individually (§ 2.27.4). One person can't sign a friend up for Space-A; each independent adult registers their own slot.
• Expired-leave members stay on the backlog (§ 2.31). Military members whose leave dates have passed remain in the Space-A backlog until their orders are formally cleared.
• Roll-call timing — no earlier than 2 hours 20 minutes before departure (§ 2.34). That's the AMC-wide floor. Terminals can roll earlier (Ramstein runs at 4h 20m, Dover around 4h), but never inside the 2h 20m window.
• Once you're on the manifest, no other Space-A passenger can bump you (§ 2.34.3). Don't worry about a higher- category Space-A traveler arriving later and displacing you.
• But Space-R (duty) passengers CAN bump Space-A (§ 2.72). Late-arriving duty travelers do displace Space-A. The bumped Space-A passenger keeps their original sign-up date and time — you go back into the backlog, not to the bottom.
• Weights are actual, not estimated (§ 2.43). PSAs ask for your real body weight and carry-on weight at check-in; both feed into load planning. Don't round.
• The 19-seat cap on cargo flights is real (§ 4.7.5). Verbatim: “Load Planning must leave a pallet position open to accommodate palletized baggage for organic aircraft carrying 20 or more passengers.” The paragraph's Note adds the escape hatch that affects what you bring: “If the mission payload does not allow enough space for a baggage pallet, ATOC will communicate with the aircrew to approve floor loading of the baggage or limit passengers to hand carried baggage.” In practice: if every Space-A traveler packs down to one carry-on plus a small personal item, the crew can often seat more than 19 — see the FAQ below.
• Diverted flights — who pays (§ 2.77). If a Patriot Express mission diverts to a location with no onward Space-A availability, the contract carrier is responsible for your meals, billets, and onward movement. If the diversion stop DOES have onward Space-A availability, those costs are on you.
• Head tax and FIS are separate fees (§ 2.105). Head tax applies to PE passengers arriving or departing the customs territory of the U.S. The Federal Inspection Service (FIS) fee is a separate CBP-passenger-arrival fee, charged only to Space-A passengers (not Space-R). The combined $41.63 you pay at Ramstein is base $23.40 head tax + ~$18 FIS.
• Cashless payment is the rule, not the exception (§ 2.101). Terminals accept cash, credit/debit, and government travel cards, but most now run card-only — Ramstein went cashless on 1 January 2025, and Hickam and SeaTac followed earlier. Travel with a card.

Read the full regulation: DAFI 24-605V2 (PDF, 30 January 2025, 193 pages). Chapter 2 (Passenger and Fleet Operations) covers most of what Space-A travelers will care about.

1. Pick a window. You can sign up up to 60 days before your intended travel. Earlier sign-ups win tiebreakers within a category, so submit as soon as your window opens.
2. Choose terminals.Sign up at every terminal you'd be willing to fly from. Most travelers sign up at 3–5 terminals to maximize their chances.
3. Submit a sign-up form. You can email the terminal directly (form on the AMC travel page), use the AMC online sign-up form, or drop off a form in person. List up to five destination countries.
4. Confirm your sign-up.Wait for the auto-reply or confirmation. If you don't get one within 24 hours, call the terminal.
5. Monitor the 72-hour schedule.Once your sign-up is active, watch the 72-hour flight boards on this site or the terminal's Facebook page for matching flights.

"Roll call" is when the terminal announces the flight, releases the seat count, and calls names in priority order. You must be physically present at the terminal at roll-call time— if your name is called and you aren't there, you're skipped.

Arrive at least 2–3 hours before roll call. Mark your bags, have ID and passport ready, and listen for announcements. If you're selected, you'll be directed to check in, clear security, and board — the whole process can happen fast, so stay close to the gate.

If you're not selected, your sign-up rolls over automatically to the next flight. No action needed unless you want to add destinations or cancel.

Space-A demand isn't evenly distributed across the year. If you can pick when you travel, the windows below tend to be 3–10× harder to get on than a typical week.

DoWEA (Department of War Education Activity) runs schools for military families overseas and at some CONUS bases. When DoWEA goes on break, the rotators fill — these are the most reliable seat-competition spikes in the calendar.

Europe and Pacific each follow one region-wide calendar; every district within the region breaks together. Americas is the exception: each district mirrors its local public-school calendar and can vary by a week or two.

Year-to-year drift is small — Thanksgiving and spring shift with the calendar week; winter consistently brackets Dec 22 – Jan 2. Source: DoWEA Regional Calendars.

Which terminals to watch: European breaks push traffic through Ramstein, BWI, JB McGuire-Dix-Lakehurst, and Andrews. Pacific breaks spike Hickam, SeaTac, Travis, Yokota, and Kadena. Americas breaks barely move Space-A — those families are already in CONUS.

• DoD ID card and, if applicable, DD Form 2 (Retired)
• Passport (and visa/SOFA documents if required)
• Printed sign-up confirmation and leave form if on active duty
• Two checked bags (≤70 lbs each) and one carry-on per person
• Entertainment — cargo aircraft are loud; bring earplugs and noise-canceling headphones
• Warm layers — cargo bays get cold at altitude, even in summer
• Snacks and water — meals may not be served
• Power bank — seats don't usually have outlets
• Cash and credit card with no foreign transaction fees
• A backup commercial ticket option — always have Plan B

Most cargo-aircraft Space-A flights (C-17, C-5, KC-135, C-130) cost nothing. The fees you'll encounter apply to Patriot Express commercial-charter flights and are federal air-transportation excise taxes collected on behalf of the IRS — they are not optional and apply to every passenger regardless of category.

Current rates (per IRS Form 720):

• International head tax — $23.40 per passenger. Charged on any Patriot Express departure or arrival outside the US (Ramstein, Yokota, Kadena, Spangdahlem, etc.).
• Alaska/Hawaii facilities tax — $11.70 per passenger. Applies to departures from or arrivals at Alaska or Hawaii (Anchorage, Honolulu/Hickam, Kona).
• Domestic segment tax — $5.30 per segment. Rarely applies to Space-A; most domestic Patriot Express legs are bundled into an international itinerary.
• Optional meal fee — typically $5–15. Patriot Express crews offer hot meals on long-haul legs; pay at check-in if you want one. Bring snacks regardless — meals are not guaranteed.

Children under 2 not occupying a seat are exempt from the head and facilities taxes. Pay by card at the terminal check-in counter — most terminals no longer accept cash.

Rates update periodically; check the IRS Form 720 instructions for the current quarter if you want to verify before travel.

Space-A travelers cannot bring pets. Pet transportation on AMC aircraft is reserved for service members and DoW civilians traveling on Permanent Change of Station (PCS) orders. Space-A, leisure, and TDY/TAD travelers are not eligible — if you're flying Space-A, plan to make commercial arrangements for your pet or leave them at home.

The rules below apply to PCS travelers on the Patriot Express (the only AMC mission that accepts pets — cargo aircraft never do). They live in the Beginner's Guide because PCS travelers often also use Space-A for the legs around their move, and the same pet eligibility rule (PCS orders) governs which segment can carry the pet.

• Reserve through the departure terminal. Call ahead — pet space cannot be reserved online. Some terminals open a pet wait-list when sign-ups go active.
• Health paperwork. US-issued APHIS/USDA health certificate (within 10 days of travel for most destinations), proof of current rabies vaccination, and a microchip that meets ISO 11784/11785 standards. International destinations have their own additional requirements — Japan, the UK, and Australia in particular have multi-month lead times for import permits.
• Kennel must meet IATA Live Animal Regulations. Hard-sided, ventilated on at least three sides, large enough for the pet to stand and turn. Soft-sided carriers are not accepted in cargo hold.
• Pet fees. Set by AMC and assessed per kennel based on combined pet + kennel weight. Rates change — confirm with the terminal at booking. Cash is rarely accepted; bring a card.
• Hawaii requires quarantine.Hawaii is rabies-free and runs one of the world's strictest pet entry programs. The 5-Day-Or-Less program requires advance paperwork submitted to Hawaii's Animal Industry Division at least 30 days before arrival, with two FAVN rabies blood tests spaced 30 days apart. Skipping this paperwork means a 120-day quarantine at your expense.
• Service animals follow ADA rules and are not counted against the pet slot allocation, but you still need the required destination-country health paperwork.

For the official policy and current fee schedule, see AMC's Pet Travel page.

• Be flexible.If your dates, destinations, or priorities are rigid, Space-A will frustrate you. The travelers who do best are those who can pivot to a different flight on 30 minutes' notice.
• Sign up for multiple terminals.Travis, JB Charleston, and BWI often have overlapping Europe/Pacific routes — sign up at all three if you're heading in that direction.
• Watch inbound arrivals, not just outbound schedules. A crew that just arrived at Ramstein is very likely to fly back to the US the next day — inbound traffic is a leading indicator.
• Mid-week flights are often less competitive. Fridays and weekends fill up with leisure travelers; Tuesdays and Wednesdays are usually your best bet.
• Don't book Space-A return legs on a deadline. You may get stuck. Plan a buffer of 3–7 days before any hard commitment.
• Dress respectfully.No ripped clothing, offensive slogans, or revealing attire — you're representing the military community.
• Ask the terminal staff questions. They deal with first-timers every day and are usually happy to walk you through the process.

• AMC Travel Page (Official) ›

  Air Mobility Command's official Space-A travel portal.

• Space-A Sign-Up (Take A Hop) ›

  Unofficial tool to manage sign-ups at multiple terminals at once.

• AMC Gram ›

  Official newsletter with terminal updates and schedule changes.

• Space-A Travel Facebook Groups ›

  Active community — traveler reports, tips, real-time gouge.

• Dirk Pepperd's Space-A Pages ›

  Classic reference site with terminal contacts and FAQs.

• Poppin Smoke — Space-A Guide ›

  In-depth written guides and printable checklists.