Spektrum's AS3X+ receiver lineup looks like someone sneezed on a keyboard: AR631+, AR637T+, AR8360T+, AR10360T+. Behind the part numbers is a simple ladder. The first number(s) after "AR" tell you the channel count, a "T" means full-range telemetry, and the "+" means the newer AS3X+ stabilization.
All four share the same core: DSMX, AS3X+ gyro stabilization, SAFE flight envelope protection and setup through Forward Programming from your transmitter. So the decision comes down to three questions: how many channels does your plane need, do you want telemetry, and how big (or electrically noisy) is the airframe? Here's how we answer them on the bench.
The Short Answer
Pick the smallest receiver that covers your servo count: the AR631+ for most 4 to 6-servo park and sport planes, the AR637T+ if you want full-range telemetry and altitude in a 6-channel plane, the AR8360T+ for flaps, retracts and lights, and the AR10360T+ for large planes with many wing servos or two remote receivers.
- All four have AS3X+ and SAFE, run on 3.5 to 9 V, and set up through Forward Programming.
- Telemetry is worth it once you fly bigger or pricier planes; altitude and battery voltage on your wrist prevent a lot of dead-stick landings.
- Big or carbon-heavy planes benefit from an SRXL2 remote receiver; only the T models have ports for one.
1. Count Your Channels First
Channel count is the hard limit. Get it wrong and you're shopping twice.
List every servo and function
Write down each thing that needs its own receiver output:
- Throttle (the ESC): 1
- Ailerons: 1 if both share a Y-harness, 2 if each has its own channel (needed for flaperons and some setups)
- Elevator: 1 (2 if split without a Y)
- Rudder: 1
- Flaps: 1 or 2
- Retracts, lights, bomb drop or tow release: 1 each
Worked examples
- Sport trainer, separate ailerons: throttle, 2 ailerons, elevator, rudder = 5. Fits an AR631+ or AR637T+.
- Warbird with flaps and retracts: throttle, 2 ailerons, elevator, rudder, flaps, retracts = 7. You need the AR8360T+.
- Large scale plane with split flaps, lights and a tow release: 9 or more. That's AR10360T+ territory.
Leave a spare channel when you can. Planes grow lights and smoke systems.
Don't forget the switches
SAFE mode and AS3X gain are controlled from switches on your transmitter, assigned during Forward Programming setup. Those use transmitter channels too. Our Forward Programming guide walks through the setup, and your receiver manual lists which channels can be used for gain and mode.
2. The Four Receivers Compared
Specs below are from Spektrum's product pages as of July 2026. All four list a 3.5 to 9 V input range and AS3X+ with SAFE set up through Forward Programming.
| AR631+ | AR637T+ | AR8360T+ | AR10360T+ | |
|---|---|---|---|---|
| Channels | 6 | 6 | 8 | 10 |
| AS3X+ and SAFE | Yes | Yes | Yes | Yes |
| Telemetry range | Fly-by range | Full range | Full range | Full range |
| Built-in barometer (altitude, vario) | No | Yes | Yes | Yes |
| SRXL2 remote receiver ports | 0 | 1 | 1 | 2 |
| Weight | 8 g | 12 g | 16 g | 18 g |
| Typical plane | Park flyer, 4-6 servos | Sport plane, wants altitude data | Flaps, retracts, lights | Large scale, many wing servos |
AR631+: the default for park and sport planes
The Spektrum AR631+ 6-Channel AS3X+ & SAFE Receiver is a full-range, 6-channel receiver with AS3X+ and SAFE at 8 grams. It has no remote receiver port, and its telemetry is "fly-by" range: useful near you, not at the far end of the pattern. It can pass Smart ESC data such as voltage and current (Spektrum). For most foam park flyers it's all you need.
AR637T+: same size class, full telemetry
The Spektrum AR637T+ 6-Channel AS3X+/SAFE Telemetry Receiver keeps 6 channels and adds full-range integrated telemetry with a built-in barometer for altitude and variometer data, one SRXL2 remote receiver port, and two antennas (Spektrum). It's our pick for a nicer 6-channel sport plane or a glider, where the vario helps you find lift.
AR8360T+: the warbird and flaps receiver
The Spektrum AR8360T+ 8-Channel AS3X+ & SAFE Telemetry Receiver moves to 8 channels with the same full-range telemetry, barometer and one SRXL2 port (Spektrum). Flaps, retracts and lights fit without combining functions on Y-harnesses.
AR10360T+: big planes, more RF paths
The Spektrum AR10360T+ 10-Channel AS3X+ & SAFE Telemetry Receiver has 10 channels, full-range telemetry with a barometer and two SRXL2 remote receiver ports. Spektrum also highlights AS3X+ refinements such as Stop Lock and Release Rate parameters and improved gyro filtering (Spektrum). Choose it for large-scale airframes or anything with lots of wing servos.
3. Telemetry, Remote Receivers and Installation
Once channel count is settled, these details decide between neighbors on the ladder.
Do you need telemetry?
For a first foam trainer, not really; a timer does the job. Telemetry earns its keep when the plane is expensive, far away or flown on a long timer. Battery voltage, altitude and signal quality on your transmitter screen let you land on numbers instead of guesses. With a Spektrum Smart ESC and battery, data comes over one wire with no extra sensors.
Our rule of thumb at the counter: if losing the plane would cost more than the price gap between the AR631+ and AR637T+, buy the T. The built-in barometer alone is worth it on gliders and on planes you fly high, where judging altitude by eye gets unreliable. Set a low-voltage alarm on your transmitter the first time you bind it.
When to add a remote receiver
Carbon fiber, metal and large fuel tanks can block 2.4 GHz signals. A Spektrum SRXL2 DSMX Remote Serial Telemetry Receiver on the T-series receivers adds a second RF path mounted in a different spot and orientation. We recommend one on large planes and on anything with a lot of carbon.
Mounting and antenna tips
- Mount the receiver firmly with the orientation you'll enter in Forward Programming; AS3X+ depends on it.
- Keep antennas away from carbon, metal and power wiring, and point them in different directions on two-antenna receivers.
- Use a battery and BEC that can handle all your servos under load; brownouts look like radio problems.
- Bind, set failsafe and range check before the first flight.
If it won't bind, see our receiver binding fixes. For more on Forward Programming menus, Horizon's AR637T programming overview is a good reference.
Conclusion
Choosing a Spektrum receiver is mostly arithmetic. Count your servos and functions, add one for growth, then decide whether full-range telemetry and remote receiver support are worth it for this plane. AR631+ for most park flyers, AR637T+ for 6-channel planes that deserve telemetry, AR8360T+ for flaps and retracts, AR10360T+ for big planes.
Shop Spektrum receivers, or bring your plane to the store. We'll count channels with you and can set up AS3X+ and SAFE on the bench.
Gear Mentioned in This Guide
Spektrum AR631+ 6-Channel AS3X+ & SAFE Receiver
Our best-selling receiver for park and sport planes.
Shop now
Spektrum AR8360T+ 8-Channel AS3X+ & SAFE Telemetry Receiver
For flaps, retracts and lights.
Shop now
Spektrum AR10360T+ 10-Channel AS3X+ & SAFE Telemetry Receiver
Ten channels and two remote-receiver ports for big airframes.
Shop now
Spektrum SRXL2 DSMX Remote Serial Telemetry Receiver
Adds an RF path in big or carbon-heavy planes.
Shop now
Frequently Asked Questions
Which Spektrum receiver do I need?
Count every servo and function that needs its own channel. Up to 6: AR631+ or AR637T+. Seven or eight: AR8360T+. More than eight: AR10360T+. Then choose a T model if you want full-range telemetry.
Do I need telemetry on my RC plane?
Not for a first foam trainer, where a flight timer is enough. On bigger or more valuable planes, live battery voltage, altitude and signal data help you land before trouble starts.
What's the difference between the AR631+ and AR637T+?
Both are 6-channel AS3X+ and SAFE receivers. The AR637T+ adds full-range telemetry, a built-in barometer for altitude and vario, two antennas and a port for an SRXL2 remote receiver. The AR631+ is lighter and has fly-by range telemetry.
Do all these receivers have AS3X+ and SAFE?
Yes. All four include AS3X+ stabilization and SAFE flight envelope protection, set up through Forward Programming from a compatible Spektrum transmitter.
Which transmitters work with these receivers?
Any Spektrum DSMX transmitter can bind and fly them. Forward Programming for AS3X+ and SAFE setup needs a compatible Spektrum transmitter with current firmware, such as the NX and iX series.
Can I add a remote receiver to the AR631+?
No. The AR631+ has no remote receiver port. Choose the AR637T+, AR8360T+ (one SRXL2 port each) or AR10360T+ (two ports) if you need one.
Sources and Further Reading
- Spektrum: AR631+ 6-Channel AS3X+ & SAFE Receiver (SPM-1031)
- Spektrum: AR637T+ 6-Channel AS3X+ & SAFE Telemetry Receiver (SPM-1032)
- Spektrum: AR8360T+ 8-Channel AS3X+ & SAFE Telemetry Receiver (SPM-1033)
- Spektrum: AR10360T+ 10-Channel AS3X+ & SAFE Telemetry Receiver (SPM-1034)
- Horizon Hobby: AR637T receiver programming overview
- Academy of Model Aeronautics: Safety Code
