PT — Aircraft Flight Model (.PT)¶

.PT files are the per-aircraft aerodynamics and avionics records. There are 145+ .PT files in FA_2.LIB, one per aircraft variant. They use BRF (Brent's Relocatable Format) — plain ASCII text that is parsed at game startup by SetupPT.

Tools¶

fx¶

fx pt info   F16C.PT          # field dump: thrust, speed, fuel, stall, ceiling
fx pt unpack F16C.PT -o F16C.pt.txt
fx pt pack   F16C.pt.txt -o F16C_mod.PT

See BRF.md for the full field reference (OT base fields + PT extension fields, G-envelope section, hardpoints, systemDamage array).

File Layout¶

Plain text; BRF syntax. This page documents the in-memory PLANE_TYPE binary struct the text compiles into — the text-format field reference lives in BRF.md.

In-Memory Struct: PLANE_TYPE¶

At game startup _SetupPT (0x4A7220) chains through _SetupNT → _SetupOT → FUN_004a6b10 to load each .PT file and lock its binary data into memory. The binary layout is needed for runtime patching, network-sync analysis, and AI parameter extraction.

Layout derived by direct byte-counting against F16C.PT (type_size = 660 = 0x294). Offsets marked confirmed were read or written directly by decompiled the game executable code. All others are inferred from packing (BRF fields written sequentially, no alignment padding).

file_name is not stored in the binary struct — it is the LIB lookup key only. ot_names is a single ptr; it points to a name-record holding all name strings.

Total layout: OBJ_TYPE 166 B (0x00–0xA5) + NPC_TYPE 20 B (0xA6–0xB9) + PLANE_TYPE main 258 B (0xBA–0x1BB) + 9 hardpoints × 24 B (0x1BC–0x293) = 660 B ✓

OBJ_TYPE section (0x00–0xA5, 166 B)¶

Offset	Size	Field	BRF type	Notes
`0x00`	1	struct_type	byte	= 5 for PT
`0x01`	2	type_size	word	F16C = 660
`0x03`	2	instance_size	word	confirmed — `_T_AddObj@12` reads `(short)(ptr+3)`
`0x05`	4	ot_names	ptr	single ptr to name record; F16C = ptr
`0x09`	4	ot_flags	dword	F16C = `$806bf3` (flyable, visible in library)
`0x0D`	2	obj_class	word	confirmed — `_SetupOT` tests bits `0xc000`/`0x2000`/`0x1000`/`0x800`/`0x400`/`0x200`
`0x0F`	4	shape	ptr	confirmed — `_SetupOT` passes `iVar4+0x0f` to `FUN_004a71e0`; string compared to `"eject_SH"`
`0x13`	4	shadow_shape	ptr	confirmed — `_SetupOT` reads `(char*)(iVar4+0x13)` for shape-name derivation
`0x17`	4	(damage_shape_a)	ptr	filled by `_SetupOT` (`"_a"` variant); dword 0 in source BRF
`0x1B`	4	(damage_shape_b)	ptr	filled by `_SetupOT` (`"_b"` variant); dword 0 in source BRF
`0x1F`	2	Unknown	word	F16C = 0; possibly dst_debris_pos[0]
`0x21`	2	Unknown	word	F16C = 0; possibly dst_debris_pos[1]
`0x23`	2	Unknown	word	F16C = 30; possibly dst_debris_pos[2]
`0x25`	4	(damage_shape_c)	ptr	filled by `_SetupOT` (`"_c"` variant); dword 0 in source BRF
`0x29`	4	(damage_shape_d)	ptr	filled by `_SetupOT` (`"_d"` variant); dword 0 in source BRF
`0x2D`	2	Unknown	word	F16C = 30; possibly dmg_debris_pos[0]
`0x2F`	2	Unknown	word	F16C = 0
`0x31`	2	Unknown	word	F16C = 0
`0x33`	4	dmg_type / damage_set	dword	F16C = 0; written `_Rand(2)+1` at destruction, selects the `{_C,_D}` wreck pair when `2` — see shape-selection.md
`0x37`	4	year_available	dword	F16C = 1984 (F-16C service entry year)
`0x3B`	2	max_vis_dist	word	F16C = 148
`0x3D`	2	camera_dist	word	F16C = 0
`0x3F`	2	laser_targeting_sig	word	F16C = 88
`0x41`	2	ir_signature	word	F16C = 88
`0x43`	2	rcs_signature	word	F16C = 100
`0x45`	2	hit_points	word	F16C = 100
`0x47`	2	dmg_planes	word	F16C = 0
`0x49`	2	dmg_ships	word	confirmed — `_T_AddObj@12` reads as `DAT_0050ce8e` (crash damage threshold); F16C = 92
`0x4B`	2	dmg_structs	word	F16C = 255
`0x4D`	2	dmg_armor	word	F16C = 255
`0x4F`	2	dmg_other	word	F16C = 255
`0x51`	2	Unknown	word	F16C = 255
`0x53`	2	Unknown	word	F16C = 255
`0x55`	1	explosion_type	byte	F16C = 30
`0x56`	1	crater_size	byte	F16C = 0
`0x57`	4	empty_weight	dword	F16C = 14,567 lbs (matches real F-16C)
`0x5B`	2	Unknown	word	F16C = 199
`0x5D`	16	movement info	8×word	speed/accel params; F16C = 0,16380,14560,−14560,16380,0,0,0
`0x6D`	16	movement dwords	4×dword	F16C = ^0,^0,^300,^60000
`0x7D`	4	utilProc	symbol	F16C = `_PLANEProc`
`0x81`	4	loopSound	ptr
`0x85`	4	secondSound	ptr
`0x89`	4	engineOnSound	ptr
`0x8D`	4	engineOffSound	ptr
`0x91`	1	(byte)	byte	F16C = 1
`0x92`	16	sound params	8×word	F16C = 15000,320,160,20,1600,0,20,60
`0xA2`	4	hudName	ptr

NPC_TYPE section (0xA6–0xB9, 20 B)¶

Offset	Size	Field	BRF type	Notes
`0xA6`	4	ctType	dword	F16C = 0
`0xAA`	4	ctName	ptr
`0xAE`	1	(byte)	byte	F16C = 12
`0xAF`	1	(byte)	byte	F16C = 32
`0xB0`	1	(byte)	byte	F16C = 20
`0xB1`	2	(word)	word	F16C = 32767
`0xB3`	2	(word)	word	F16C = 0
`0xB5`	1	(byte)	byte	F16C = 9 (hardpoint count)
`0xB6`	4	hards	ptr	→ hardpoints array

PLANE_TYPE section (0xBA–0x1BB, 258 B)¶

Offset	Size	Field	BRF type	Notes
`0xBA`	4	carrier_flags	dword	F16C = `$11` (land-based); see BRF.md carrier_flags table
`0xBE`	4	env	ptr	→ G-envelope section in same file
`0xC2`	2	neg_g_count	word	F16C = −4 (number of negative-G envelope entries)
`0xC4`	2	pos_g_count	word	F16C = 9
`0xC6`	2	max_speed_sl	word	F16C = 1342 mph (sea level)
`0xC8`	2	max_speed_36k	word	F16C = 1934 mph (36,000 ft)
`0xCA`	130	aero block	65×word	control-authority, stall/spin and landing-gate parameters — every word now code-traced via the `_cgt` type-record mirror (`0x50D268 + off`); see § The 65-word aerodynamic block for the full per-word map
`0x14C`	1	num_engines	byte	F16C = 1
`0x14D`	2	Unknown	word	F16C = 0; unlisted in BRF.md
`0x14F`	4	military_thrust	dword	F16C = 17,687 lbf (≈ F100-PW-229 dry)
`0x153`	4	afterburner_thrust	dword	F16C = 32,000 lbf
`0x157`	2	throttle_accel	word	F16C = 40 %/sec
`0x159`	2	throttle_decel	word	F16C = 60 %/sec
`0x15B`	2	tv_min_angle	word	F16C = 0 (no thrust vectoring)
`0x15D`	2	tv_max_angle	word	F16C = 0
`0x15F`	2	tv_speed	word	F16C = 0
`0x161`	2	fuel_consumption_mil	word	F16C = 2
`0x163`	2	fuel_consumption_ab	word	F16C = 16
`0x165`	4	fuel_capacity	dword	F16C = 6,972 lbs (matches real F-16C internal fuel)
`0x169`	2	aero_drag	word	F16C = 256 (baseline)
`0x16B`	2	g_drag	word	F16C = 33
`0x16D`	2	airbrake_drag	word	F16C = 256
`0x16F`	2	wheel_brake_drag	word	F16C = 102
`0x171`	2	flap_drag	word	F16C = 76
`0x173`	2	gear_drag	word	F16C = 23
`0x175`	2	weapons_bay_drag	word	F16C = 0
`0x177`	2	flaps_lift	word	F16C = 51
`0x179`	2	drag_loaded	word	F16C = 30
`0x17B`	2	g_drag_loaded	word	F16C = 13
`0x17D`	2	gear_pitch	word	F16C = 40
`0x17F`	2	max_landing_speed	word	F16C = 40 ft/sec
`0x181`	2	max_side_speed	word	F16C = 40 ft/sec
`0x183`	2	max_sink_rate	word	F16C = 2560 ft/sec
`0x185`	2	max_landing_pitch	word	F16C = 5120
`0x187`	45	systemDamage[]	byte×45	subsystem hit thresholds; F16C values range 6–150
`0x1B4`	2	misc_per_flight	word	F16C = 10 (maintenance man-hours)
`0x1B6`	2	repair_multiplier	word	F16C = 10
`0x1B8`	4	mtow	dword	F16C = 33,000 lbs

Hardpoints section (0x1BC–0x293, 9 × 24 B)¶

F16C.PT has 9 hardpoints. Each hardpoint is 24 bytes: 8×word + ptr (4B) + byte + word + byte.

Offset	Size	Field	Notes
`+0x00`	2	hld	loading-data flags
`+0x02`	2	offset_x	ft right/left
`+0x04`	2	offset_y	ft up/down
`+0x06`	2	offset_z	ft fore/aft
`+0x08`	2	slew_heading	1° = 182
`+0x0A`	2	slew_pitch
`+0x0C`	2	slew_limit_heading
`+0x0E`	2	slew_limit_pitch
`+0x10`	4	default_type	ptr to weapon filename
`+0x14`	1	weight	hundreds of lbs
`+0x15`	2	quantity
`+0x17`	1	location	see BRF.md location codes

Engine Notes¶

Setup call chain¶

_SetupPT  (0x4A7220)  -- thin wrapper
  └─ _SetupNT  (0x4A7200)  -- NT-layer init
       ├─ FUN_004a6b10(param_1)  -- MM handle → raw data ptr
       └─ _SetupOT  (0x4A6EB0)  -- OT-layer init: resolves shape ptrs via RMAccess_8
            └─ FUN_004a71e0(ptr)  -- loads one SH file: *ptr = _RMAccess_8(*ptr, 0x8000)

FUN_004a71c0  (0x4A71C0)  -- single-object variant; calls FUN_004a71e0 on shape fields

_SetupOT reads six shape ptr fields in the binary struct and resolves each via _RMAccess_8 (load from LIB). For flying objects (obj_class & 0xc000 ≠ 0) it also derives four damage-state shape names (_a / _b / _c / _d suffix) from shadow_shape, writes them into the struct, and resolves them.

Entry points¶

VA	Symbol	Role
`0x4A7200`	`_SetupNT`	NT-layer wrapper; calls `FUN_004a6b10` + `_SetupOT`
`0x4A7220`	`_SetupPT`	PT entry point; thin wrapper calling `_SetupNT`
`0x4A71C0`	`FUN_004a71c0`	Single-object shape loader; calls `FUN_004a71e0` on shape fields
`0x4A6EB0`	`_SetupOT`	OT-layer shape resolver; patches +0x0f/+0x13/+0x17/+0x1b/+0x25/+0x29
`0x4A71E0`	`FUN_004a71e0`	Resolves one shape ptr: `ptr = _RMAccess_8(ptr, 0x8000)`
`0x4A6B10`	`FUN_004a6b10`	MM handle → raw data ptr (`(int)(param+0xf)`, with MM lock if bit 1 of `+0xe`)
`0x4A6B30`	`FUN_004a6b30`	BRF record lookup + string→binary conversion via `_RMType_4` / `_RMFind_4`

The 65-word aerodynamic block (0xCA–0x14B)¶

The 65 words at 0xCA–0x14B are the flight-model tuning table. They are named here by code trace, not by value-guessing: at startup GetCurObj copies the active aircraft's PLANE_TYPE record into the _cgt type-record mirror at base 0x50D268 byte-for-byte, so PT offset X is read by the engine as DAT_[0x50D268 + X] (anchored by exact hits — fuel_consumption_mil at PT 0x161 = DAT_0050d3c9, military_thrust at 0x14F = DAT_0050d3b7, g_drag at 0x16B = DAT_0050d3d3). Enumerating every reference into 0x50D332–0x50D3B3 (aero block) gives the consumer of each word. Every word has a consumer — none are engine-unused. Words 0xCA–0xF8 are consumed as two block-copied limit vectors (see below), which is why the middle words of those blocks carry no direct xref of their own.

The 12 stall/spin words (0x128–0x13E) confirm and now position the fields BRF.md already named but could not place; the remaining words are newly named. F16C values shown; "per-a/c" = varies by aircraft, "const" = identical across the eight sampled .PT files (F16C/F14/A10/B52/AH64/AV8/C130/F117).

Control-authority limit vectors (0xCA–0xF8, words 0–23). _COBv@0 (0x477EA0) block-copies words 0–11 into the live control buffer 0x547338; _COBrv@0 (0x477ED0) block-copies words 12–23 into 0x547350 and scales them down by battle-damage (DAT_0050ce8e) and control-surface loss (DAT_00522547) — i.e. these are the max control-response limits, degraded as the airframe takes hits.

word	off	field	F16C	reader / evidence
0	`0xCA`	accel_runway (BRF)	−73	`_COBv` block[0]
1	`0xCC`	decel_runway (BRF)	0	`_COBv` block
2	`0xCE`	roll_speed_min (BRF)	73	`_COBv` block
3	`0xD0`	roll_speed_max (BRF)	73	`_COBv` block
4	`0xD2`	pull_rate (BRF)	−146	`_COBv` block
5	`0xD4`	neg_g_limit (BRF)	146	`_COBv` block
6–11	`0xD6`–`0xE0`	ground/low-speed handling limits (cont.)	7,7,−146,146,73,73 · const	`_COBv` block words 6–11; ±-paired rate limits, roles inferential
12–15	`0xE2`–`0xE8`	rotational-authority axis A {neg,pos,rate,accel}	−270,270,362,724 · per-a/c	`_COBrv` block; fighters ±270, bombers ±30
16–19	`0xEA`–`0xF0`	rotational-authority axis B {neg,pos,rate,accel}	0,0,9,9 · per-a/c	`_COBrv` block
20–23	`0xF2`–`0xF8`	rotational-authority axis C {neg,pos,rate,accel}	−45,45,90,90 · per-a/c	`_COBrv` block

Stick-to-motion gains and turn coordination (0xFA–0x116, words 24–46). The three primary control axes are proven by their _StickInput_28 calls in _FMFlight@0 (0x47B020): each is driven by a specific pilot input, so the axis identity is definitive.

word	off	field	F16C	reader / evidence
24	`0xFA`	pitch-input → pitch-rate gain (`×/9`)	20 · const	`_FMFlight` `DAT_0050d362 * pitchIn / 9`
25	`0xFC`	forward-motion scale (`×256`)	70 · const	`_MovePlane@0` (`0x476AE0`)
26	`0xFE`	vertical/reverse-motion scale (`×−256`)	15 · const	`_MovePlane@0`
27	`0x100`	AI visual-detection / contrail interval factor	115 · per-a/c	`FUN_0047759b` (time-of-day-scaled spotting timer)
28–31	`0x102`–`0x108`	rudder turn-coordination axis {neg,pos,rate,accel}	−4,4,4,9	`_FMFlight` `_StickInput(&DAT_0050d007, …, _rudder)`, speed/G-scaled
32	`0x10A`	adverse-yaw (roll→yaw) coupling	10 · const	`_FMFlight` `DAT_0050d02b = DAT_0050d372 * rollRate`
33	`0x10C`	sideslip / yaw drag coefficient	128 · const	`FUN_0047a970` (× sideslip); also `PROJGuideLoft`
34	`0x10E`	yaw/heading response rate	5 · per-a/c	`_FMFlight` `DAT_0050d00f += d376·resp`; `PROJGuideLoft`
35–38	`0x110`–`0x116`	roll axis {neg,pos,rate,accel}	−90,90,362,724	`_FMFlight` `_StickInput(&DAT_0050d033, …, _stickX)`
39–42	`0x118`–`0x11E`	pitch axis {neg,pos,rate,accel}	−90,90,362,724	`_FMFlight` `_StickInput(&DAT_0050d037, …, _stickY)`
43–46	`0x120`–`0x126`	yaw axis {neg,pos,rate,accel}	−90,90,362,724	`_FMFlight` `_StickInput(&DAT_0050d03b, …, _rudder)`

Stall / spin model (0x128–0x13E, words 47–58). These are the BRF.md stall/spin fields, now pinned to their binary offsets. Names are BRF.md's; offsets and readers are the new evidence.

word	off	field (BRF name)	F16C	reader / evidence
47	`0x128`	stall_warn_delay	512 · per-a/c	`?CheckForEvents2` fires the stall-warning event; `_FMFlight`
48	`0x12A`	stall_duration	512 · per-a/c	`?CheckForEvents2`; `_FMFlight` `d08d < DAT_0050d392`
49	`0x12C`	stall_severity	256	`_FMFlight` (`DAT_0050d394`)
50	`0x12E`	stall_pitch_down (deg/sec)	30 · const	`_FMFlight` `_MatchF24(&pitch, −0x5A00, …)` drives nose to −90°; `?PROJEventProc`
51	`0x130`	spin_entry_ease (0 = harder)	0 · per-class	`FUN_0047ccb0` sets spin state `d08c=3`; fighters 0, bombers 1, helo 2
52	`0x132`	spin_exit_ease (neg = harder)	−2 · per-class	`FUN_0047cdb0` recovery selector (−2 / −1); `_FMFlight`
53–54	`0x134`–`0x136`	spin_yaw_low / _high (deg/sec)	120,180 · const	`_FMFlight` `FUN_0047ce70(lo, hi, spinPhase)`
55–56	`0x138`–`0x13A`	spin_aoa_low / _high (deg)	30,70 · const	`_FMFlight` `FUN_0047ce70`
57–58	`0x13C`–`0x13E`	spin_bank_low / _high (deg)	15,5 · const	`_FMFlight` `FUN_0047ce70`

Gear pitch and landing gate (0x140–0x14A, words 59–64). Word 59 is the gear-down nose-up trim; words 60–64 are the universal landing-quality gate (identical in every .PT) that _CheckLandingParms@0 (0x477140) scores — each threshold overshoot returns 5 (warning) or 6 (bad landing).

word	off	field	F16C	reader / evidence
59	`0x140`	gear-down pitch-trim authority (`× 0xB6`)	0 · per-a/c	`_FMUpdateGearPitch@0` (`0x4514C0`); AV8 = 3
60	`0x142`	landing gate: reference speed (fail if exceeded by `>0x32`)	330 · const	`_CheckLandingParms`; `?HUDDrawSpeed` reads it as the HUD approach ref
61	`0x144`	landing gate: max sink rate (fail if `>10` over)	51 · const	`_CheckLandingParms`
62	`0x146`	landing gate: pitch/AoA limit	95 · const	`_CheckLandingParms`; `?HUDDrawAlt`
63	`0x148`	landing gate: attitude limit 1 (fail if `>0x14` over)	25 · const	`_CheckLandingParms`
64	`0x14A`	landing gate: attitude limit 2 (fail if `>0x14` over)	10 · const	`_CheckLandingParms`

Confidence: the three primary axes (roll/pitch/yaw, words 35–46) and the stall/spin/landing blocks (words 47–64) are reader-proven. The two block-copied limit vectors (words 0–23) have a proven consumer (_COBv/_COBrv) and proven damage-scaling role, but the per-word breakdown inside words 6–23 is inferred from the ±-paired numeric structure and is annotated as such. Method is reproducible with scripts/ghidra/run_ghidra.sh over the 0x50D332–0x50D3B3 range.

Open Questions¶

1. Debris-position candidates¶

The three 2-byte unknowns at 0x1F/0x21/0x23 and three at 0x2D/0x2F/0x31 are plausible candidates for dst_debris_pos[3] and dmg_debris_pos[3] (i16[3] each per BRF.md), but the 0x23/0x2D values of 30 don't obviously map to debris-offset coordinates — needs a second PT file comparison to confirm.

Status: open — re-static (#54)

Formats: BRF — full BRF field reference for all PT fields, hardpoints, G-envelope; OT — OT base fields that PT inherits; JT — weapon/projectile types loaded via SetupJT (0x4A7230); SH — 3D model format referenced by shape / shadow_shape ptr fields.