Cessna 188 AGwagon / AGtruck / AGhusky

The Cessna 188 is a purpose-built single-seat agricultural airplane produced by Cessna from 1966 to 1983 (with final deliveries trickling out of Wichita in 1985 as the last light-single lines were shut down). Cessna designed the 188 from a clean sheet to compete with the Piper PA-25 Pawnee / PA-36 Pawnee Brave in the crop-dusting and aerial-application market, leveraging Cessna 180/185 tailwheel DNA but with a low wing, a chemical hopper between the engine and the pilot (acting as a crash barrier), and a high-visibility rear cockpit. A total of 3,976 airframes were built across four variants: 53 AGpickups, 1,589 AGwagons, 1,949 AGtrucks, and 385 AGhuskys. The 188 was the backbone of U.S. and Australian small-field ag work in the 1970s and early 1980s, and a meaningful fleet (several hundred) is still actively flying ag in 2026, though the heavier, more powerful Air Tractor (AT-301 through AT-802F Fire Boss) AT-402/502 has largely displaced the 188 in commercial operations. Today most 188s on the civil register are owned either by small owner-operator ag outfits or by private pilots who have converted them to non-ag utility haulers.

Book cruise is largely irrelevant for an ag airplane — it flies with dispersal gear hanging in the breeze (spray booms or spreader) that kills 15-20 knots. A stripped AGtruck will see 105-110 KTAS ferry; with booms, plan 90 KTAS. What actually matters is working performance at 8-15 feet AGL with a full 2,000-lb chemical load: the IO-520-D AGtruck climbs out of a short strip at 3,300 lb landing weight strong, but at 4,200 lb takeoff with 280 gallons of water in the hopper, ground roll stretches to 1,400+ ft on grass and climb drops to ~400 fpm. The turbocharged AGhusky is the only variant that holds respectable performance above 4,000 ft field elevation — it was specifically sold into the U.S. mountain West and the Australian Darling Downs. Vne is low (~143 KIAS) because the airframe is optimized for slow, low-G pull-ups at pattern altitude, not speed.

The 188 is unique in this wiki because "range" is almost a nuisance spec. The mission is 10-30 minute working loops from a strip adjacent to the field, with the hopper — not the fuel tanks — governing every flight.

• Full fuel, empty hopper (ferry configuration): 54 gal usable × 6 lb = 324 lb fuel, leaving ~1,660 lb for pilot, booms, and equipment. Range ~256 nm with booms on, ~310 nm clean. This is the only configuration in which a 188 travels any distance.
• Working load, short fuel (normal ag): 25 gal fuel (~150 lb) + pilot (200 lb) + spray gear (150 lb) + 2,000 lb chemical + 5% margin = just under 4,200 lb MGW for the AGtruck. Endurance per load ~90 minutes, covers 200-400 acres depending on application rate.
• Max payload: The airframe is hopper-volume-limited before it is weight-limited for most liquid loads. Water at 8.34 lb/gal fills 280 gal to 2,335 lb; most agricultural liquids are lighter, so the 2,000 lb placarded hopper load is the practical ceiling.
• The AGhusky advantage: The turbocharged 4,400 lb MGW T188C maintains full working payload up to 6,000-8,000 ft density altitude, which the normally aspirated AGtruck cannot — this is why AGhuskys are disproportionately found in the U.S. mountain West and inland Australia.

• Cargo Hauling (9): Nearly 2,000 lb useful load in a single-engine fixed-gear airframe with a 280-gallon hopper is exceptional. See Cargo Hauling — the 188 is the archetype of "liquid/granular cargo in a low-and-slow airframe." Non-ag haul missions require restricted-to-normal conversions which are rare.
• Surveying (4): Possible as a single-seat low-altitude platform if the hopper bay is converted to an equipment bay, but cost-inefficient vs. a Cessna 172 or experimental.
• Flight Training (1): Single-seat, restricted category, heavy tailwheel — disqualified.
• Cross-Country / Business (1): Single seat, no IFR, 256 nm range at 90-100 KTAS with booms. Not a traveler.
• Aerobatics (1): Not certified, low Vne, heavy.
• Local Fun (2): A small cult of ex-ag owners fly converted 188s for fun — brutal fuel burn and visibility are the main attraction, but it's a niche taste.
• Backcountry (2): Low wing and narrow-track tailwheel make it a poor off-airport choice vs. a Super Cub or 185.

Ag 188s are famously spartan. Typical working panel: airspeed, altimeter, tachometer, cylinder head and oil temps, fuel pressure, magnetic compass, a single comm radio, and a GPS guidance system for swath tracking (Satloc, Hemisphere AG, or AgNav — these are dedicated ag guidance units, not IFR navigators). Most 188s have no vacuum system and no attitude indicator at all. Conversion panels on de-restricted 188s sometimes add a Garmin GTR 225/GNC 215 plus a basic ADS-B transponder (GTX 335) — budget $8,000-$12,000 installed. Glass panel upgrades are effectively unheard of; the airframe's working life doesn't justify it.

• Spray boom / atomizer conversions (Transland, CP Products, Micronair): Standard equipment; swapping systems costs $5,000-$15,000.
• Dry spreader (Transland, Swathmaster): Converts liquid ag to granular (seed, fertilizer, fire retardant).
• Engine upgrades: IO-520-D to IO-550 conversion (~$15,000 above overhaul) adds ~10 HP and better hot/high performance. TSIO-520 retrofits exist for AGwagon/AGtruck airframes but are rare.
• Gross weight increase STCs: Several shops offer 4,400 lb MGW for AGtrucks, matching the AGhusky.
• Wing extension / winglet kits (Micro Aerodynamics VGs): Improve low-speed handling in turns; ~$2,500.
• Ferry tank / non-ag conversion: Replaces the hopper with an auxiliary fuel tank or cargo pod for bush work. Moves the aircraft from restricted to "restricted - special purpose" or requires a full type certificate data sheet re-entry, which is paperwork-heavy.

See Maintenance Ecosystem:

• Parts availability: Good. Textron still supports the 188 through its single-engine parts channel and Cessna Flyer Association. Hopper gates, spray booms, and ag-specific hardware are supported by Transland and similar specialty shops. Airframe structural parts (spar caps, wing attach fittings) can be custom-fabricated from Cessna drawings if OEM stock is dry.
• Mechanic familiarity: Specialist. A general A&P can do an annual, but ag-experienced shops (Air Repair in Mississippi, Queen Bee Air Specialties in Idaho, and a handful of Australian and Canadian shops) are where most serious 188 work happens.
• Annual inspection: $3,500-$6,500 for a clean hull; $8,000-$15,000+ is common when corrosion, cylinder work, or fitting inspections are needed.
• Hourly direct operating cost (ag use): $85-$120/hr fuel + oil, plus reserves of $40-$60/hr for engine and $20-$30/hr for airframe. Commercial ag operators typically carry $150-$180/hr DOC.
• Expensive items: IO-520-D overhaul ($48,000-$55,000), cylinder set ($8,000-$12,000), prop overhaul ($4,000-$6,000), wing attach inspection and repair ($5,000-$25,000), corrosion repair (open-ended).

Per Aircraft Valuation Methodology:

• Engine: TBO impact is huge. A fresh IO-520-D overhaul (~$52,000) on an AGtruck adds $30,000-$40,000 to hull value. A runout engine subtracts roughly the same.
• Corrosion history: A hangared, well-washed 188 with a documented wash-down routine commands 25-40% more than a tied-down hull.
• Restricted vs. conversion: Aircraft still on restricted category for ag use have a narrower buyer pool but are the only ones usable for commercial spraying.
• Airframe total time: Ag airframes commonly see 10,000-15,000 hours; spar and fitting condition matters far more than raw TT.
• Price tiers (2026):
  • Project / runout / poor corrosion: $50,000-$70,000
  • Working AGwagon 230, mid-time engine: $70,000-$95,000
  • Clean AGtruck, mid-time IO-520-D, booms: $100,000-$140,000
  • Fresh engine AGtruck or AGhusky, good airframe: $150,000-$180,000
  • Turbocharged AGhusky with low hours and fresh engine: $180,000-$220,000

• AD 2011-10-09 (repetitive): Seat rail and seat lock inspection — applies across Cessna 100/200 series including 188. Low cost but recurring.
• AD 2020-07-12 / TCM cylinder ADs: Continental cylinder AD cycles affect IO-520/TSIO-520 powered 188s. Budget for cylinder work as a routine 500-hour item in ag use.
• Alternate static source placard AD: Minor one-time fix.
• Wing attach fittings and spar carry-through: Not a formal AD but a well-known inspection point — ag 188s see repeated high-G pull-ups that fatigue the wing root. A detailed eddy-current inspection at pre-buy is mandatory.
• Corrosion from chemicals: The defining 188 problem. Fertilizer and pesticide residue attacks the lower fuselage, spar caps, and control cables. A 188 that was not religiously washed after every load is effectively scrap. Lift every inspection panel.
• Hopper gate and door seals: Leak chemicals into the cockpit area; expensive to source new.
• Exhaust cracks (IO-520): Common to all 300 HP Continental Cessnas; budget $2,500-$4,000 at annual.
• Engine time abuse: Ag engines are run hard — full power on takeoff, chopped on pull-ups, quick descents. Expect cylinder work well before TBO.

See GA Insurance Underwriting. The 188 lives in a specialized ag insurance pool:

• Commercial ag use: $8,500-$18,200/year for qualified pilots with $1M liability and $200K hull (per current market quotes). Underwriting requires ag-specific training, minimum hours (typically 500 TT, 100 in type, 50 ag PIC), and a signed-off operations plan.
• Private non-ag use (converted hull): $2,500-$5,000/year, but carriers are few — most commercial lines will not write a single-seat tailwheel 188 even for private use.
• Hull values: Insurers cap most 188s at $150,000 agreed value without appraisal.
• Endorsements required: Tailwheel, high-performance, often a chemical handler endorsement for commercial policies.
• Claims history: Ag 188s suffer wire strikes, terrain impacts from steep pull-ups, and engine failures during low-altitude work; loss rates are meaningfully higher than any normal-category single.