HPU  HUD.Projector.Unit 
HRD  Home.Routing.Domain 
HSA  Horizontal.Stabilizer.Actuator 
HSACE  Horizontal.Stabilizer.Actuator.Control.Electronics 
HS-DSAD  High.Speed.Frame.Relay.Service.Access.Device 
HSI  Horizontal.Situation.Indicator..An.indicator.that. 
displays.bearing,.glideslope,.distance,.radio. 
source,.course.and.heading.information. 
HSIT  Hardware.and.Software.Integration.Test 
HSL  Heading.Select 
HSR  High.Stability.Reference 
HSRP  Hot.Standby.Routing.Protocol 
HST  High.Speed.Transceivers 
HSTA  Horizontal.Stabilizer.Trim.Actuator 
HTC  Highest.Two-way.Channel 
HUD  Head-Up.Display 
HVPS  High-Voltage.Power.Supply 
HW  Hardware 
HWCI  Hardware Configuration Item 
HWND  Headwind 
HW/SW  Hardware/Software 
HX  Heat.Exchanger 
HYD  Hydraulic 
HYDIM  Hydraulic.Interface.Module 
Hz  Hertz.(cycles.per.second) 
IS  Integrated.Information.System 
IACSP  International.Aeronautical.Communications. 
Service.Provider 
I/F  Interface 
IA  International.Alphabet.Number.5 
IAGS  Integrated.ARINC.Ground.Station 
IANA  Internet.Assigned.Number.Authority 

IAOA Indicated.Angle-of-Attack IAOPA International Council of Aircraft Owners and Pilots
Associations IAPA Instrument.Approach.Procedures.Automation IAPS Integrated.Avionics.Processing.System IARP Inverse.Address.Resolution.Protocol IAS Indicated.Airspeed.is.the.speed.indicated.by.
a.differential.pressure.airspeed.indicator.that. measures.the.actual.pressure.differential.in. the.pitot-static.head..It.is.the.actual.instrument.
indication for a given flight condition.
IASP  IAS Profile: An autopilot/flight director mode that commands the aircraft to fly pre-programmed
airspeed.values. IATA International.Air.Transport.Association IAW In.Accordance.With IBAC International.Business.Aviation.Council IC (.1.).Integrated.Circuit..
(.2.).Intercabinet
ICAO  International Civil Aviation Organization
(Montreal) ICC IAPS.Card.Cage ICCA International Civil Certification Authorities ICCAIA International.Coordinating.Council.of.Aerospace.