The U.S. aircraft register, updated daily
Parts · Cabin, seats and restraints

Nipple

6 failure reports named the nipple in the last ten years, 30 since 1995, most often on the Airbus Helicopters EC-135 now H135; the condition most often found was "blocked". 160 FAA approvals let 23 companies make a replacement nipple, Rockwell Collins INC holding the most (49).

Reports by year

01234199520022010201912026
Reports by year, as a table
reports
19951
19962
19973
19982
20012
20024
20041
20052
20071
20081
20101
20111
20131
20152
20181
20191
20222
20231
20261

Which system the reports file it under last ten years

Cabin, seats and restraints3Engine2Fuel system1
Reports by system, as a table
reports
Cabin, seats and restraints3
Engine2
Fuel system1

Models most often reporting it last ten years

Airbus Helicopters EC-135 now H1351Airbus A3211Boeing 7371Boeing 7671Embraer EMB-135 ERJ 135 and Legacy1
Models most reported, as a table
reports
Airbus Helicopters EC-135 now H1351
Airbus A3211
Boeing 7371
Boeing 7671
Embraer EMB-135 ERJ 135 and Legacy1

How it failed the condition found, last ten years

blocked1cracked1defective1missing1overheated1sheared1
Conditions found, as a table
reports
blocked1
cracked1
defective1
missing1
overheated1
sheared1

Engines most often reporting it

CFM International CFM56-7B27 1Pratt & Whitney Canada PW206B2 1

Approved replacement parts 160 parts manufacturer approvals

A parts manufacturer approval (PMA) lets a company other than the aircraft's maker make a nipple and sell it as an approved part for the models named. These are the companies holding such approvals for a nipple:

Rockwell Collins INC 49Parker Hannifin CORP 22Ta Manufacturing 16Aerofit INC 16Safran Electronics & Defense, Avionics USA, LLC 12Monogram Systems 10Parker Stratoflex 6Faber Enterprises INC 5Continental Motors INC 3Continental Aerospace Technologies INC 3Airmotive Engineering CORP 3Safran Electronics & Defense Avionics USA LLC 2Rosemount Aerospace INC 2Meggitt Oregon 2Wencor LLC 1We Aerotech Services INC 1Symetrics INC 1Superior Air Parts INC 1Scott Aviation (Now Avox Systems, INC.) 1Scott Aviation 1Pacific Sky Supply INC 1Growth Industries INC 1Denezol Tool CO INC 1

For these models most: Boeing 747 (30), Boeing 737 (21), Boeing 757 (16), Boeing 777 (15), Mcdonnell Douglas DC-10 (13), Embraer ERJ 170 E170 and E175 (13), Boeing 767 (12), Boeing 707 (10), Mcdonnell Douglas MD-10 (7), Douglas DC-10 (7), Airbus A320 (7), Boeing 727 (6).

MakerPartReplacesFitsGrantedStatus
Safran Electronics & Defense Avionics USA LLCNipple Assy - .75 Size, MS33656-8 Fitting 0060-0101-10060-0101-1De Havilland... DHC-8-100 Series, DHC-8-200 Series,...2024-02-13current
Safran Electronics & Defense Avionics USA LLCNIPPLE ASSY, .75 SIZE MS33514-12 END, WATER FILL 4739-12-44739-12-4ATR - GIE Avions de... ATR42-200, ATR42-300, ATR42-3202022-11-08current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - OPEN TYPE FLARED TUBE - MS33656 1012-8A1012-8ABoeing 707-300 SERIES, 707-300B SERIES,...2021-12-02current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - FLANGE LAV. DRAIN 2651-219-22651-219-2Dassault Aviation MYSTERE FALCON 9002021-10-08current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE 8789-108789-10Dassault Aviation MYSTERE FALCON 50, MYSTERE FALCON 9002021-10-08current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE ASSY, 1.00 SIZE, 3/4 TUBE, MS33660 8941-28941-2Dassault Aviation MYSTERE FALCON 9002021-10-08current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE ASSY, 4.00 SIZE LAVATORY DRAIN 2651-194C2651-194CBoeing 727-200 SERIES737-200 SERIES2021-06-24current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - .75 SIZE 2126-0036-12126-0036-1Boeing 767-200 SERIES, 767-300 SERIES2021-06-24current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - CHECK VALVE ASSY, 3.00 SIZE AIR START 4663-44663-4Boeing 767-200 SERIES, 767-300 SERIES2021-05-07current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - CHECK VALVE ASSY, 3.00 SIZE AIR START 4663-24663-2Boeing 747-100 SERIES, 747-200B SERIES,...2021-05-07current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE ASSY, 1.00 SIZE TO .75 MS33514-12 4709-214709-21Boeing 757-200 SERIES2021-05-07current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE ASSEMBLY, 1 INCH ROYLYN TO 3/4 INCH BULKHEAD TUBE... 4126-0040-24126-0040-2Boeing 757-200 SERIES2021-05-07current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - CHECK VALVE ASSY, 3.00 SIZE AIR START 46764676Boeing MD-10-10F SERIES, MD-10-30F SERIES2021-05-07current
Safran Electronics & Defense, Avionics USA, LLCNIPPLE - CHECK VALVE ASSY, 3.00 SIZE AIR START 4663-84663-8Boeing 737-100 SERIES, 737-200 SERIES,...2021-05-07current
Continental Aerospace Technologies INCNipple Assembly, Primer AEL7422563D21408 74255 STD-546Lycoming O-235-C1, C1B, C2A2020-01-06current
Continental Aerospace Technologies INCNipple, Oil Filter Adapter AEL22792Allows use of female oil filters with AEL22772Lycoming Same as AEL77852. Reference Service...2020-01-06current
Continental Aerospace Technologies INCNipple, Straight AEL7573975739 LW-16562Lycoming O-320-A1B, A3B, B1B2020-01-06current
Parker Hannifin CORPNipple 10101C74710101C747Airbus A330-9412019-05-20current
Parker Hannifin CORPNipple 158512-601HR158512-601HREmbraer ERJ 170-100 LR, ERJ 170-100 STD, ERJ...2017-01-11current
Continental Motors INCNipple, Straight AEL7573975739 LW-16562Lycoming O-320-A1B, A3B, B1B2017-01-08current
Continental Motors INCNipple, Oil Filter Adapter AEL22792Allows use of female oil filters with AEL22772Lycoming Same as AEL77852. Reference Service...2017-01-08current
Continental Motors INCNipple Assembly, Primer AEL7422563D21408 74255 STD-546Lycoming O-235-C1, C1B, C2A2017-01-08current
Rockwell Collins INCNipple, Open Type 1002-16A1002-16AMitsubishi YS-11, YS-11A-200, YS-11A-3002016-06-01current
Rockwell Collins INCNipple Assembly 4739-12-44739-12-4Aerospatiale ATR 42-200, ATR 42-300, ATR 42-3202016-06-01current
Rockwell Collins INCNipple 1061-0003NAPratt & Whitney Engine JT9D-7R4H12016-06-01current
Rockwell Collins INCNipple, Open Type 1002-12A1002-12AMitsubishi YS-11, YS-11A-200, YS-11A-3002016-06-01current
Rockwell Collins INCNipple Assembly 4739-12-44739-12-4Boeing 707-300, 737-200, 737-3002016-06-01current
Rockwell Collins INCNipple Assembly 0060-0850060-085Airbus B2-1C, B2K-3C, B4-2C2016-06-01current
Rockwell Collins INCNipple Assembly 4739-12-54739-12-5Boeing 727-2002016-06-01current
Rockwell Collins INCNipple Assembly 4709-214709-21Boeing 757-2002016-06-01current
Rockwell Collins INCNipple 2651-15A2651-15AFokker F272016-06-01current
Rockwell Collins INCNipple Assembly 4709-34709-3Boeing 707-300, 727-200, 737-1002016-06-01current
Rockwell Collins INCNipple Assembly 1052-16C1052-16CBoeing 707-3202016-06-01current
Rockwell Collins INCNipple/Check Valve 46764676McDonnell Douglas DC-10-10, DC-10-10F, DC-10-152016-06-01current
Rockwell Collins INCNipple/Cap Assembly 1061-00041061-0004McDonnell Douglas DC-10-10, DC-10-10F, DC-10-152016-06-01current
Rockwell Collins INCNipple Assembly 1061-00101061-0010Pratt & Whitney PW4152, PW4156, PW4156A2016-06-01current
Rockwell Collins INCNipple 2651-174C2651-174CFokker F272016-06-01current
Rockwell Collins INCNipple Assembly 8668-168668-16Boeing 707-3202016-06-01current
Rockwell Collins INCNipple Assembly 0060-00620060-0062McDonnell Douglas DC-10-10, DC-10-10F, DC-10-152016-06-01current
Rockwell Collins INCNipple 1061-00041061-0004Boeing MD-10-10-F, MD-10-30-F2016-06-01current
Rockwell Collins INCNipple 4709-64709-6Fokker F282016-06-01current
Rockwell Collins INCNipple 1052-8A1052-8AFokker F272016-06-01current
Rockwell Collins INCNipple Assembly 4259-314259-31ATR 42-300-3202016-06-01current
Rockwell Collins INCNipple Assembly 0060-00610060-0061McDonnell Douglas DC-10-10, DC-10-10F, DC-10-152016-06-01current
Rockwell Collins INCNipple Assembly 4709-44709-4Boeing 727-200, 737-200, 737-3002016-06-01current
Rockwell Collins INCNipple Assembly 4739-12-44739-12-4Airbus A320-111, A320-211, A320-2312016-06-01current
Rockwell Collins INCNipple Assembly 0067-00010067-0001Boeing 747-4002016-06-01current
Rockwell Collins INCNipple Assembly 8652-128652-12Boeing 707-120, 707-320water2016-06-01current
Rockwell Collins INCNipple 2651-259-12651-259-1Boeing MD-10-10-F, MD-10-30-F2016-06-01current
Rockwell Collins INCNipple 0060-00610060-0061Boeing MD-10-10-F, MD-10-30-F2016-06-01current
Rockwell Collins INCNipple 1052-12A1052-12AFokker F272016-06-01current
Rockwell Collins INCNipple 4126-0040-24126-0040-2Boeing 757-2002016-06-01current
Rockwell Collins INCNipple Assembly 47039-347039-3Airbus A320-111, A320-211, A320-2122016-06-01current
Rockwell Collins INCNipple Assembly 2651-219-22651-219-2Airbus A320-111, A320-211, A320-2312016-06-01current
Rockwell Collins INCNipple Assembly 0060-0940060-094Airbus B2-1C, B2K-3C, B4-2C2016-06-01current
Rockwell Collins INCNipple Assembly 0060-00630060-0063Boeing 707-300, 747-100, 747-2002016-06-01current
Rockwell Collins INCNipple 1002-12C1002-12CMcDonnell Douglas DC-10-10, DC-10-10F, DC-10-152016-06-01current
Rockwell Collins INCNipple Assembly 0016-0021-10016-0021-1Boeing 757-200, 737-4002016-06-01current
Rockwell Collins INCNipple Assembly 1052-16A1052-16ABoeing 707-3202016-06-01current
Rockwell Collins INCNipple Assembly 2651-194C2651-194CBoeing 737-200, 727-2002016-06-01current
Rockwell Collins INCNipple 1002-12C1002-12CBoeing MD-10-10-F, MD-10-30-F2016-06-01current
Rockwell Collins INCNipple 4126-0040-34126-0040-3Boeing 757-2002016-06-01current
Rockwell Collins INCNipple Assembly 1012-8A1012-8ABoeing 707-3202016-06-01current
Rockwell Collins INCNipple 0060-00620060-0062Boeing MD-10-10-F, MD-10-30-F2016-06-01current
Rockwell Collins INCNipple 1002-16C1002-16CBoeing MD-10-10-F2016-06-01current
Rockwell Collins INCNipple Assembly 47039-347039-3Aerospatiale ATR 42-200, ATR 42-300, ATR 42-3202016-06-01current
Rockwell Collins INCNipple/Cap Assembly 1061-00031061-0003McDonnell Douglas DC-10-402016-06-01current
Rockwell Collins INCNipple Assembly 0060-001030060-00103Airbus B2-1C, B2K-3C, B4-2C2016-06-01current
Rockwell Collins INCNipple 1002-16C1002-16CMcDonnell Douglas DC-10-10, DC-10-10F2016-06-01current
Rockwell Collins INCNipple Assembly 0060-0131-10060-0131-1Boeing 777-300 Series2016-06-01current
Rockwell Collins INCNipple Assembly 4709-34709-3Airbus A320-111, A320-211, A320-2312016-06-01current
Superior Air Parts INCNipple, Gage SL02G21382P/N 02G21382, P/N 02A21382, P/N 75447Lycoming Engines IO-360-A1A, -A1B, -A1B62015-03-23current
Parker Hannifin CORPNipple, Press Cap Assembly 920341-1920341-1Airbus A350-9412014-12-02current
Wencor LLCNipple 321-061-101-0WE321-061-101-0Airbus A318 Series, A318 Model -111, A318 Model -1122014-08-11current
Monogram SystemsNipple, Rinse w/ Heater Assembly 77000-028S824Z001-1Boeing 787-82014-01-23current
Meggitt OregonNipple SI-2401-1BACN18H7Boeing 757-200 Series2012-06-03current
Meggitt OregonNipple SI-2401BACN18H5Boeing 757-200 Series, 767-200 Series,...2012-06-03current
Parker Hannifin CORPNipple 158508-601HPAermacchi S.P.A. 1580508-601HP 15E0819Embraer ERJ 170-100 STD, ERJ 170-100 LR, ERJ...2011-08-09current
Parker Hannifin CORPNipple 158506-601CDAermacchi S.P.A. 158506-601CD 15E0821Embraer ERJ 170-100 STD, ERJ 170-100 LR, ERJ...2011-08-09current
Parker Hannifin CORPNipple 158512-601HRAermacchi S.P.A. 158512-601HR 15E0820Embraer ERJ 170-100 STD, ERJ 170-100 LR, ERJ...2011-08-09current
Parker Hannifin CORPNipple 158506-601CDAermacchi S.P.A. 158506-601CD 15E0821Embraer ERJ 170-100 STD, ERJ 170-100 LR, ERJ...2011-04-26current
Parker Hannifin CORPNipple 158508-601HPAermacchi S.P.A. 1580508-601HP 15E0819Embraer ERJ 170-100 STD, ERJ 170-100 LR, ERJ...2011-04-26current
Parker Hannifin CORPNipple 158512-601HRAermacchi S.P.A. 158512-601HR 15E0820Embraer ERJ 170-100 STD, ERJ 170-100 LR, ERJ...2011-04-26current
Denezol Tool CO INCNipple AWJ7197-501AWJ7197-501McDONNELLDOUGLAS DC-10-10, DC-10-10F, DC-10-152010-11-22current
Parker Hannifin CORPNipple 158512-601HR158512-601HREmbraer ERJ 170-100 LR, ERJ 170-100 STD, ERJ...2010-05-16current
Parker Hannifin CORPNipple (PDOX) 155504-1155504-1Boeing 777F Series2009-05-18current
Parker Hannifin CORPNipple 158506-601CD158506-601CDEmbraer Empresa ERJ 170-200 LR, ERJ 170-100 STD, ERJ...2009-04-28current
Parker Hannifin CORPNipple 158512-601HR158512-601HREmbraer Empresa ERJ 170-100 LR, ERJ 170-100 STD, ERJ...2009-04-28current
Parker Hannifin CORPNipple Assembly - Waste Drain Valve 10101B577-210101B577-2Boeing 717-2002009-04-27current
Monogram SystemsNipple, Drain 38000-577-20138000-577-201Airbus A380-8612008-10-23current
Monogram SystemsNipple, Overflow 38000-575-20138000-575-201Airbus A380-8612008-10-23current
Monogram SystemsNipple, Fill Drain 38000-570-20138000-570-201Airbus A380-8612008-10-23current
Monogram SystemsNipple, Drain 38000-577-20138000-577-201Airbus A380-8612008-10-23current
Monogram SystemsNipple, Fill Drain 38000-570-20138000-570-201Airbus A380-8612008-10-23current
Monogram SystemsNipple, Overflow 38000-575-20138000-575-201Airbus A380-8612008-10-23current
Monogram SystemsNIPPLE, FILL DRAIN 38000-570-20138000-570-201Airbus A380-841, -8422007-02-08current
Monogram SystemsNIPPLE, DRAIN 38000-577-20138000-577-201Airbus A380-841, -8422007-02-08current
Monogram SystemsNIPPLE, OVERFLOW 38000-575-20138000-575-201Airbus A380-841, -8422007-02-08current
Aerofit INCNipple BACN18D6AJ4BACN18D6AJ4Boeing 747-4002005-12-15current
Aerofit INCNipple BACN18D5AJ2BACN18D5AJ2Boeing 737-100, 737-200, 747-1002005-12-15current
Aerofit INCNipple-(customer) BACN18D8AJ6BACN18D8AJ6Boeing 747-100, 747-200, 747-3002005-12-15current
Aerofit INCNipple BACN18D5AD2BACN18D5AD2Boeing 737-100, 737-200, 737-3002005-12-15current
Parker Hannifin CORPNipple 155510-5155510-5Eurocopter Deutschland MBB-BK117C-2, EC1352005-08-30current
Parker Hannifin CORPNipple 155510-5155510-5Eurocopter Deutschland MBB-BK117C-22005-05-10current
Parker Hannifin CORPNipple 158512-601HR, Aermacchi...170-48010-501, 170-48011-501Embraer Empresa ERJ-170-100 STD, ERJ-170-100 LR2005-04-24current
Parker Hannifin CORPNipple 158506-601HP, Aermacchi...170-48010-501, 170-48011-501Embraer Empresa ERJ-170-100 STD, ERJ-170-100 LR2005-04-24current
Parker Hannifin CORPNipple 158506-601CD, Aermacchi...170-48010-501, 170-48011-501Embraer Empresa ERJ-170-100 STD, ERJ-170-100 LR2005-04-24current
Aerofit INCNipple BACN18D5AJ2BACN18D5AJ2Boeing 737-100, 737-200, 747-1002004-05-17current
Aerofit INCNipple BACN18D4AD2BACN18D4AD2Boeing 747-100, 747-200, 747-3002004-05-17current
Aerofit INCNipple BACN18D6AJ4BACN18D6AJ4Boeing 747-100, 747-200, 747-3002004-05-17current
Aerofit INCNipple BACN18D5AD2BACN18D5AD2Boeing 737-100, 737-200, 737-3002004-05-17current
Aerofit INCNipple BACN18D5AJ4BACN18D5AJ4Boeing 747-100, 747-200, 747-3002004-05-17current
Aerofit INCNipple-(customer) BACN18D8AJ6BACN18D8AJ6Boeing 747-100, 747-200, 747-3002004-05-17current
Airmotive Engineering CORPNipple, Straight AEL7573975739, LW-16562Lycoming O-320-A1B, A3B, B1B2003-06-30current
Airmotive Engineering CORPNipple Assembly, Primer AEL7422563D21408, 74255, STD-546Lycoming O-235-C1, C1B, C2A2003-06-30current
Airmotive Engineering CORPNipple, Oil Filter Adapter AEL22792Allows use of female oil filters with AEL22772Lycoming O-235-C1, C1B, C1C2003-06-30current
Parker Hannifin CORPNipple (PDOS) 155504-19S332W110-19Boeing 777-200 Series2002-07-28current
Parker Hannifin CORPNipple (PDOS) 155504-1155504-1Boeing 777-200 Series, 777-300 Series2002-07-28current
Parker Hannifin CORPNipple, Bulkhead Assembly 155504-3155504-3Boeing 777-200 Series, 777-300 Series2002-07-28current
Parker StratoflexNipple, Bulkhead Assembly 155504-3155504-3Boeing 777-200 Series2001-10-14current
Parker StratoflexNipple (PDOS) 155504-1155504-1Boeing 777-200 Series2001-10-14current
Parker StratoflexNipple, Bulkhead (PDOS) 155504-5155504-5Boeing 777-200 Series2001-10-14current
Faber Enterprises INCNipple BACN18D5AJ2BACN18D5AJ2Boeing 737-100, -200, 747-1002000-01-26current
Faber Enterprises INCNipple- BACN18D5AD2BACN18D5AD2Boeing 737-100, -200, -3002000-01-26current
Faber Enterprises INCNipple- BACN18D4AD2BACN18D4AD2Boeing 737-100, -200, 747-1002000-01-26current
Faber Enterprises INCNipple- BACN18D6AJ4BACN18D6AJ4Boeing 747-4002000-01-26current
Faber Enterprises INCNipple BACN18D5AJ4BACN18D5AJ4Boeing 747-100, -200, -3002000-01-26current
Aerofit INCNipple BACN18D5AD2Boeing BACN18D5AD2Boeing 737-100, 737-200, 737-3001999-05-11current
Aerofit INCNipple BACN18D5AJ2Boeing BACN18D5AJ2Boeing 737-100, 737-200, 747-1001999-05-11current
Aerofit INCNipple BACN18D5AJ4Boeing BACN18D5AJ4Boeing 747-100, 747-200, 747-3001999-05-11current
Aerofit INCNipple-(customer) BACN18D8AJ6Boeing BACN18D8AJ6Boeing 747-100, 747-200, 747-3001999-05-11current
Aerofit INCNipple BACN18D4AD2Boeing BACN18D4AD2Boeing 737-100, 737-200, 747-1001999-05-11current
Aerofit INCNipple BACN18D6AJ4Boeing BACN18D6AJ4Boeing 747-4001999-05-11current
Growth Industries INCNipple - 3/4" MS33657 69036-333Kaiser Roylan 1002-12AAirbus A300, A310, A3191999-03-15current
Ta ManufacturingNipple V2651-301C10Boeing V2651-301C10Boeing 757-2001998-07-14current
Ta ManufacturingNipple V4709J016C03Boeing V4709J016C03Boeing 737-200, 737-300, 737-4001998-07-14current
Ta ManufacturingNipple V4739J012C20Boeing V4739J012C20Boeing 767-200, 767-3001998-07-14current
Ta ManufacturingNipple V26514-216COOBoeing V26514-216COOBoeing 737-100, 737-200, 747-1001998-07-14current
Ta ManufacturingNipple V2651-216C10Boeing V2651-216C10Boeing 737-100, 737-200, 737-3001998-07-14current
Ta ManufacturingNipple Assembly V1063-012C03Douglas V1063-012C03McDonnell Douglas DC-10-10, -15, -301998-07-14current
Ta ManufacturingNipple V4739J012C04Boeing V4739J012C04Boeing 737-100, 737-200, 737-3001998-07-14current
Ta ManufacturingNipple V4739J016C30Boeing V4739J016C30Boeing 747-4001998-07-14current
Ta ManufacturingNipple Assembly V8941J016C00Douglas V8941J016C00McDonnell Douglas DC-9-11, -12, -13 14-151998-07-14current
Ta ManufacturingNipple V4739J012C16Boeing V4739J012C16Boeing 747-100, 747-200, 747-4001998-07-14current
Ta ManufacturingNipple Assembly V1002-012C00Douglas V1002-012C00McDonnell Douglas DC-10-10, -15, -301998-07-14current
Ta ManufacturingNipple V4739J012C30Boeing V4739J012C30Boeing 767-200, 767-3001998-07-14current
Ta ManufacturingNipple Assembly V0060J012C61Douglas V0060J012C61McDonnell Douglas DC-10-10, -15, -301998-07-14current
Ta ManufacturingNipple Assembly V0060J016C62Douglas V0060J016C62McDonnell Douglas DC-10-10, -15, -301998-07-14current
Ta ManufacturingNipple Assembly V1002-016C00Douglas V1002-016C00McDonnell Douglas DC-10-10, -15, -301998-07-14current
Parker StratoflexNipple, Bulkhead Assembly 155504-3Boeing 155504-3Boeing 777-2001997-06-19current

The first 150 of 160.

Sources: the FAA's service difficulty reports since 1995 (a report is a part that failed and was fixed, as filed by an airline, repair station or owner; the count shows reporting as much as reliability) and the parts manufacturer approvals in the FAA's Dynamic Regulatory System. The part name is the reporters' and the approval holders' own words, reduced to the first plain words so that spellings meet.