diff --git a/src/helpers/radiolib/CustomLR1110.h b/src/helpers/radiolib/CustomLR1110.h
index cdf3cc7cf..2e536de5e 100644
--- a/src/helpers/radiolib/CustomLR1110.h
+++ b/src/helpers/radiolib/CustomLR1110.h
@@ -3,9 +3,6 @@
 #include <RadioLib.h>
 #include "MeshCore.h"
 
-#define LR1110_IRQ_HAS_PREAMBLE                     0b0000000100  //  4     4     valid LoRa header received
-#define LR1110_IRQ_HEADER_VALID                     0b0000010000  //  4     4     valid LoRa header received
-
 class CustomLR1110 : public LR1110 {
   public:
     CustomLR1110(Module *mod) : LR1110(mod) { }
@@ -22,63 +19,10 @@ class CustomLR1110 : public LR1110 {
       }
       return len;
     }
-
-    RadioLibTime_t getTimeOnAir(size_t len) override {
-  // calculate number of symbols
-  float N_symbol = 0;
-  if(this->codingRate <= RADIOLIB_LR11X0_LORA_CR_4_8_SHORT) {
-    // legacy coding rate - nice and simple
-    // get SF coefficients
-    float coeff1 = 0;
-    int16_t coeff2 = 0;
-    int16_t coeff3 = 0;
-    if(this->spreadingFactor < 7) {
-      // SF5, SF6
-      coeff1 = 6.25;
-      coeff2 = 4*this->spreadingFactor;
-      coeff3 = 4*this->spreadingFactor;
-    } else if(this->spreadingFactor < 11) {
-      // SF7. SF8, SF9, SF10
-      coeff1 = 4.25;
-      coeff2 = 4*this->spreadingFactor + 8;
-      coeff3 = 4*this->spreadingFactor;
-    } else {
-      // SF11, SF12
-      coeff1 = 4.25;
-      coeff2 = 4*this->spreadingFactor + 8;
-      coeff3 = 4*(this->spreadingFactor - 2);
-    }
-
-    // get CRC length
-    int16_t N_bitCRC = 16;
-    if(this->crcTypeLoRa == RADIOLIB_LR11X0_LORA_CRC_DISABLED) {
-      N_bitCRC = 0;
-    }
-
-    // get header length
-    int16_t N_symbolHeader = 20;
-    if(this->headerType == RADIOLIB_LR11X0_LORA_HEADER_IMPLICIT) {
-      N_symbolHeader = 0;
-    }
-
-    // calculate number of LoRa preamble symbols - NO! Lora preamble is already in symbols
-    // uint32_t N_symbolPreamble = (this->preambleLengthLoRa & 0x0F) * (uint32_t(1) << ((this->preambleLengthLoRa & 0xF0) >> 4));
-
-    // calculate the number of symbols - nope
-    // N_symbol = (float)N_symbolPreamble + coeff1 + 8.0f + ceilf((float)RADIOLIB_MAX((int16_t)(8 * len + N_bitCRC - coeff2 + N_symbolHeader), (int16_t)0) / (float)coeff3) * (float)(this->codingRate + 4);
-    // calculate the number of symbols - using only preamblelora because it's already in symbols
-    N_symbol = (float)preambleLengthLoRa + coeff1 + 8.0f + ceilf((float)RADIOLIB_MAX((int16_t)(8 * len + N_bitCRC - coeff2 + N_symbolHeader), (int16_t)0) / (float)coeff3) * (float)(this->codingRate + 4);
-  } else {
-    // long interleaving - not needed for this modem
-  }
-
-  // get time-on-air in us
-  return(((uint32_t(1) << this->spreadingFactor) / this->bandwidthKhz) * N_symbol * 1000.0f);
-}
-
+    
     bool isReceiving() {
       uint16_t irq = getIrqStatus();
-      bool detected = ((irq & LR1110_IRQ_HEADER_VALID) || (irq & LR1110_IRQ_HAS_PREAMBLE));
+      bool detected = ((irq & RADIOLIB_LR11X0_IRQ_SYNC_WORD_HEADER_VALID) || (irq & RADIOLIB_LR11X0_IRQ_PREAMBLE_DETECTED));
       return detected;
     }
 };
\ No newline at end of file