Jet pipe & nozzle flapper
27B50 jet pipe and 27A50F nozzle flapper pilot-stage units. Pilot stage cleaning, spool service, coil rebuild, seal replacement, and bench testing.
NC Servo Technology - Westland, Michigan
734-326-6666
Independent Repair Shop. Not HR Textron.
Third-Party Repair of HR Textron Servovalves
Independent third-party repair of HR Textron servovalves across the 27 series: 27E50 two-stage, 27B50 jet pipe, 27C50 direct-drive (R-DDV), and 27A50F nozzle flapper. Aerospace and defense heritage. Backed by a 19,000+ unit in-house inventory we pull aftermarket and donor parts from. NC Servo is not affiliated with HR Textron, Textron Inc., or Woodward. Working on this kind of hardware since 1975.
Three pilot-stage types
Jet pipe, nozzle flapper, and direct-drive servovalves all serviced in-house.
Aerospace heritage
Servovalves from flight controls, engine controls, and power drive applications.
One-year warranty
Standard on parts and workmanship for HR Textron repairs and rebuilt units.
Servovalve Technology
Three pilot-stage technologies under one bench
HR Textron servovalves come in three pilot-stage flavors, each with different failure patterns and different repair work. We open all three on the same bench. The technology callouts below cover what shows up on each type.
- Jet pipe servovalves (27B50): pilot pressure swings between two receiver ports based on jet position.
- Nozzle flapper servovalves (27A50F): pilot uses a flapper that varies flow between two opposing nozzles.
- Direct-drive servovalves (27C50, R-DDV): pilot stage is replaced by a direct-acting linear coil driving the spool.
- Two-stage servovalves (27E50): mechanical-feedback amplification for higher flow capability.
Service Coverage
What NC Servo does with HR Textron servovalves
HR Textron servovalves are built for high-reliability hydraulic control. The shop opens each unit, finds what failed, and rebuilds it at the component level using replacement parts from inventory or pulled off donor units when needed.
Direct-drive (R-DDV)
27C50 direct-drive servovalves. Linear coil work, position-feedback verification, spool service, and electronic driver-card checks where applicable.
Two-stage and discontinued
27E50 two-stage servovalves and older HR Textron units the OEM no longer supports. Donor parts from inventory keep older lines in service.
HR Textron Series
HR Textron 27 series on the bench
We are a small repair shop, not an HR Textron distributor. The series below are simply the ones that come through the door often enough to be familiar. If your part number is not on this list, send it anyway. We work on what we can.
27E50 two-stage
Two-stage electrohydraulic servovalves with mechanical feedback for higher flow control.
27B50 jet pipe
High-performance servovalves with jet pipe pilot stage, common in aircraft flight controls and power drive systems.
27C50 direct-drive (R-DDV)
Rotary direct-drive servovalves for position, velocity, and pressure control without a pilot stage.
27A50F nozzle flapper
Nozzle flapper servovalves for integrated hydraulic control. The 27A50F-4K03 is a representative variant.
Common Faults
What usually shows up on an HR Textron servovalve
A description of the symptom helps the diagnosis, but a part number is often enough. The categories below cover the kinds of trouble that show up on HR Textron servovalves across the three pilot-stage types.
| Pilot stage | Jet pipe nozzle plugging, flapper damage, nozzle wear, pilot-pressure null shift, or contamination in the pilot path. |
|---|---|
| Spool and body | Spool wear, contamination scoring, sticky spool action, or internal leakage past the spool on any of the 27-series valves. |
| Coil and electrical | Burned coils, position-feedback faults on R-DDV units, or driver-card failures where the model has onboard electronics. |
| Physical condition | Heat damage, contamination evidence, corroded connectors, damaged housing, or evidence of prior repair attempts. |
Repair Path
From part number to ship-back
Most HR Textron jobs follow the same four steps. Lead time varies because some repairs need parts pulled off a donor unit, so we only commit to timing once a tech has the valve on the bench.
Get in touch
Phone or email with the HR Textron part number, a quick note on the symptom, and a photo of the nameplate if it helps.
Bench review
Once the unit arrives, a tech opens it, inspects the pilot stage and spool, and runs it on the hydraulic stand to confirm what failed.
Cost & approval
We call back with the cost and a rough turnaround. Nothing happens without your sign-off.
Repair, test, ship
Failed components are replaced from inventory or off donors, the valve is verified under pressure, and the unit ships back.
Bench Verification
Each HR Textron unit gets pressurized before ship
Repaired HR Textron servovalves are checked on the hydraulic test stands before they leave. Flow, pressure gain, response, and null are verified against documented procedures for the family.
- Flow characterization across the operating range for the model.
- Pressure gain and step-response measurement against documented procedures.
- Internal and external leakage checked after seal and spool work.
- Null bias trim where the family calls for it.
Inventory & Parts Pool
A 19,000+ unit pool with HR Textron hardware in it
NC Servo's in-house inventory holds over 19,000 valves and drives accumulated since 1975, including a steady share of HR Textron 27-series servovalves. That pool is where the shop pulls aftermarket parts and donor components for older 27E50, 27B50, 27C50, and 27A50F families.
- Aftermarket and donor parts for jet pipe, nozzle flapper, and direct-drive HR Textron units.
- If we have a rebuilt match for your part number, trade in your old valve for a discount on the rebuilt.
- No match on the shelf? We can suggest a comparable HR Textron or cross-brand option, or repair yours.
- Rebuilt valves carry the same 1-year warranty as a fresh repair.
Repair Scope
Where the line is on an HR Textron repair
NC Servo works on the servovalve hardware: the body, spool, pilot stage, coils, and any onboard driver-card components. Hydraulic system design, fluid selection, and getting the valve back on the machine stay with your team or your installer.
- Internal valve work: spool service, seal replacement, pilot stage cleaning, coil rebuild.
- Direct-drive units: linear coil work and position-feedback verification.
- System pressure setup and hydraulic schematic decisions remain on your side.
- Putting the valve back on the machine follows your normal startup process.
More on HR Textron Repair
Related pages and brands
HR Textron servovalves often share a machine or a system with other aerospace-grade hydraulic hardware. The pages below cover related coverage and other servovalve brands.
Valve repair hub
The full range of servo and proportional valve repair NC Servo handles, across the brands that come through the shop.
Atchley jet pipe servovalves
Another aerospace-grade jet pipe servovalve brand the shop services. Common pairing with HR Textron on flight-control and turbine systems.
Moog servo valves
Another aerospace-heritage servovalve brand the shop services. Often paired with HR Textron on the same system.
Repair vs replace
When component-level repair makes sense versus buying new or rebuilt.
HR Textron servovalve down?
Give us a call with the 27-series part number, a photo of the nameplate, or a quick description of the symptom. We will check the shelf, and if we have a rebuilt match you can swap your old one for a discount. If we do not, we can suggest a comparable valve or repair the one you have.
FAQ
Common questions about HR Textron repair
A few things customers ask before sending a unit in. Anything not covered, give us a call at 734-326-6666.
Is NC Servo affiliated with HR Textron, Textron Inc., or Woodward?
No. NC Servo Technology is an independent, third-party repair facility and is not affiliated with, authorized by, or endorsed by HR Textron, Textron Inc., Woodward, or any related entities. All HR Textron trademarks are the property of their respective owners.
Which HR Textron servovalve types do you cover?
Single-stage, two-stage, and direct-drive servovalves across the 27 series: 27E50 two-stage, 27B50 jet pipe, 27C50 direct-drive (R-DDV), and 27A50F nozzle flapper. Send a part number to confirm coverage on anything not listed.
Do you work on jet pipe and nozzle flapper servovalves?
Yes. Both pilot-stage technologies come through the bench. Jet pipe units (like the 27B50) and nozzle flapper units (like the 27A50F) get pilot-stage cleaning, spool work, coil rebuild, and bench testing on the hydraulic stand.
Can NC Servo recover programs from a failed HR Textron unit?
Most failures are hardware, and the unit comes back working with its program intact. Corrupted programs are rare; if one is already corrupted before the unit reaches us, that's the one thing we can't recover.
How long does an HR Textron repair take?
It varies. NC Servo is a small independent shop, and lead time depends on the valve, what is wrong with it, and whether parts have to come off a donor unit. Give us a call once the unit ships in, and we can give a current estimate after a tech has looked at it.
What happens if the valve is beyond economic repair?
If the valve is not fixable, we will let you know and help source a replacement: a rebuilt match if we have one on the shelf, or a comparable HR Textron or cross-brand alternative.
What is the warranty on an HR Textron repair?
One year on parts and workmanship for repairs and rebuilt units. Standard exclusions apply for contamination, improper installation, and out-of-spec operation. Flushing and filtering the hydraulic system before reinstalling a repaired valve is recommended.
Textron Products We Service
60 models available
HR TEXTRON
TEXTRON
HR TEXTRON 27E50F-4A04-999
When your HR Textron 27E50F-4A04-999 valve fails, production stops. limited stock. NC Servo Tech offers...
TEXTRON
TEXTRON
TEXTRON DCTM-1460
When your TEXTRON DCTM-1460 valve fails, production stops. limited stock. NC Servo Tech offers expert...
HR TEXTRON WOODWARD
TEXTRON
HR TEXTRON WOODWARD 27E50F-4A02-999
Trust your HR Textron Woodward 27E50F-4A02-999 repair to a shop that understands servo and proportional...
HR TEXTRON
TEXTRON
HR TEXTRON 22232530-003-32
Stop searching for a HR Textron 22232530-003-32 replacement. Repair often restores the valve to working...
HR TEXTRON
TEXTRON
HR TEXTRON 2255788-101
Don't let a faulty HR Textron 2255788-101 valve slow you down. Our technicians specialize in...
HR TEXTRON
TEXTRON
HR TEXTRON 25500024
Stop searching for a HR Textron 25500024 replacement. Repair often restores the valve to working...
HR TEXTRON
TEXTRON
HR TEXTRON 27A10F-4L02
When your HR Textron 27A10F-4L02 valve fails, production stops. subject to availability. NC Servo Tech...
HR TEXTRON
TEXTRON
HR TEXTRON 27A50F-2F02
Trust your HR Textron 27A50F-2F02 repair to a shop that understands servo and proportional valve...
HR TEXTRON
TEXTRON
HR TEXTRON 27A50F-3D01
Stop searching for a HR Textron 27A50F-3D01 replacement. Repair often restores the valve to working...
HR TEXTRON
TEXTRON
HR TEXTRON 27A50F-4K02C
Stop searching for a HR Textron 27A50F-4K02C replacement. Repair often restores the valve to working...
HR TEXTRON
TEXTRON
HR TEXTRON 27B50F-3C02-999
When your HR Textron 27B50F-3C02-999 valve fails, production stops. limited stock. NC Servo Tech offers...
HR TEXTRON
TEXTRON
HR TEXTRON 27C20F-3B01-010
Professional Reconditioning for your HR Textron 27C20F-3B01-010. We offer tested solutions. Inquire today!
All Textron Products
- HR TEXTRON 27E50F-4A04-999 - Model: 27E50F-4A04-999
- TEXTRON DCTM-1460 - Model: DCTM-1460
- HR TEXTRON WOODWARD 27E50F-4A02-999 - Model: 27E50F-4A02-999
- HR TEXTRON 22232530-003-32 - Model: 22232530-003-32
- HR TEXTRON 2255788-101 - Model: 2255788-101
- HR TEXTRON 25500024 - Model: 25500024
- HR TEXTRON 27A10F-4L02 - Model: 27A10F-4L02
- HR TEXTRON 27A50F-2F02 - Model: 27A50F-2F02
- HR TEXTRON 27A50F-3D01 - Model: 27A50F-3D01
- HR TEXTRON 27A50F-4K02C - Model: 27A50F-4K02C
- HR TEXTRON 27B50F-3C02-999 - Model: 27B50F-3C02-999
- HR TEXTRON 27C20F-3B01-010 - Model: 27C20F-3B01-010
- HR TEXTRON 27C20F-4D02 - Model: 27C20F-4D02
- HR TEXTRON 27C20F4D02G - Model: 27C20F4D02G
- HR TEXTRON 27E50F-4A01-999 - Model: 27E50F-4A01-999
- TEXTRON 265394-16 - Model: 265394-16
- HR TEXTRON 27E50F-4A06-999 - Model: 27E50F-4A06-999
- HR TEXTRON 27G30F-5F02J-999 - Model: 27G30F-5F02J-999
- HR TEXTRON 27G50F-1E09-995 - Model: 27G50F-1E09-995
- HR TEXTRON 27G50F-3B02-995 - Model: 27G50F-3B02-995
- HR TEXTRON 27G50F-3B06-999 - Model: 27G50F-3B06-999
- HR TEXTRON 27G50F-5A01-999 - Model: 27G50F-5A01-999
- HR TEXTRON 27G50F-5A06 - Model: 27G50F-5A06
- HR TEXTRON 27G50F-5F02-J999NC - Model: 27G50F-5F02-J999NC
- HR TEXTRON 27G50F-9F02-999 - Model: 27G50F-9F02-999
- HR TEXTRON 27N14F-40E - Model: 27N14F-40E
- HR TEXTRON 27S30F6F10 - Model: 27S30F6F10
- HR TEXTRON 995 = 10% OL EL COMP - Model: 995 = 10% OL EL COMP
- TEXTRON 22255958 - Model: 22255958
- TEXTRON 265396-16 - Model: 265396-16
- HR TEXTRON 27E50F-4A04 - Model: 27E50F-4A04
- TEXTRON 27E50F-4A06-999 - Model: 27E50F-4A06-999
- HR TEXTRON WOODWARD 27E50F-3B09-995 - Model: 27E50F-3B09-995
- HR TEXTRON 10851-25 - Model: 10851-25
- HR TEXTRON 22255958 - Model: 22255958
- HR TEXTRON 25001011-001 - Model: 25001011-001
- HR TEXTRON 27A10F-2F01 - Model: 27A10F-2F01
- HR TEXTRON 27A50F-0G04A - Model: 27A50F-0G04A
- HR TEXTRON 27A50F-2F06A - Model: 27A50F-2F06A
- HR TEXTRON 27A50F-4K01 - Model: 27A50F-4K01
- HR TEXTRON 27B50F-3C01G-999 - Model: 27B50F-3C01G-999
- HR TEXTRON 27C00F-4D01 - Model: 27C00F-4D01
- HR TEXTRON 27C20F-4D01-999 - Model: 27C20F-4D01-999
- HR TEXTRON 27C20F-SK05 - Model: 27C20F-SK05
- HR TEXTRON 27E50F-4A01 - Model: 27E50F-4A01
- TEXTRON 263820 - Model: 263820
- HR TEXTRON 27E50F-4A06-995 - Model: 27E50F-4A06-995
- HR TEXTRON 27G30F-1F17-999 - Model: 27G30F-1F17-999
- HR TEXTRON 27G50F-1E02 - Model: 27G50F-1E02
- HR TEXTRON 27G50F-1F09-999 - Model: 27G50F-1F09-999
- HR TEXTRON 27G50F-3B06 - Model: 27G50F-3B06
- HR TEXTRON 27G50F-5A01 - Model: 27G50F-5A01
- HR TEXTRON 27G50F-5A02J-999 - Model: 27G50F-5A02J-999
- HR TEXTRON 27G50F-5F02-999 - Model: 27G50F-5F02-999
- HR TEXTRON 27G50F-9C09-995 - Model: 27G50F-9C09-995
- HR TEXTRON 27G50FV1E02 - Model: 27G50FV1E02
- HR TEXTRON 27S30F-6F05 - Model: 27S30F-6F05
- HR TEXTRON 917AS2092 - Model: 917AS2092
- HR TEXTRON 999 = ZERO LAP - Model: 999 = ZERO LAP
- TEXTRON 22255788-101 - Model: 22255788-101
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