Type 2 diabetes on metformin and single-pilot IR operations
First Officer D, 49, holds an IR(A) and a Class 1 medical valid until 10 February 2026. In August 2025 he was diagnosed with type 2 diabetes. His HbA1c is 7.4%; he is on metformin 500 mg twice daily. He has no retinopathy, no neuropathy, no nephropathy, and no history of hypoglycaemia. His BMI is 31. He flies single-pilot IR operations in a turboprop and wants to continue. He has not informed his AME yet. He has a simulator session next week and asks whether he can attend as pilot flying and whether he can continue line flying while the assessment is pending. He says metformin does not cause hypoglycaemia, so he thinks there is no issue.
1. Is a diagnosis of type 2 diabetes on metformin automatically disqualifying for a Class 1 medical?
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No. Type 2 diabetes treated with metformin can be compatible with Class 1 certification, but it requires aeromedical assessment. The key issues are control, absence of complications, and the risk of hypoglycaemia. Metformin alone carries a low hypoglycaemia risk, but the pilot must still be assessed. The AME will need the diagnosis, treatment, HbA1c, and evidence of no end-organ complications. Certification may be issued with a limitation and follow-up. It is not a case of automatic disqualification, but it is also not a case for self-clearance. The pilot's own view that metformin is low-risk is not the test; the assessor must determine fitness on the evidence.
2. Can he act as pilot flying in the simulator next week and continue line flying before the AME review?
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He should not continue line flying until the AME has reviewed the case and confirmed fitness. A new diagnosis and ongoing medication are a change in medical fitness. For the simulator session, the position is less clear because it is not line flying, but if he is acting as pilot flying in an FSTD for training or checking, the operator and instructor should be told. The safe approach is to inform the AME before the session and follow the advice. He should not rely on his own view that metformin is low-risk. If the AME has not cleared him, he should not exercise licence privileges. The simulator session may be able to proceed as training, but it must not be treated as evidence of medical fitness for line flying.
3. What documentation is likely to be required for certification?
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The AME will likely require a report from the treating physician or endocrinologist covering diagnosis, treatment, HbA1c trend, hypoglycaemia history, and complications. An eye examination may be needed for retinopathy screening. The assessor will consider whether the condition is stable and whether the medication is acceptable. A limitation may require periodic HbA1c and medical review. The pilot should provide accurate records and not omit the diagnosis. If control is poor or complications are present, certification may be deferred. The overall judgement is whether the risk of incapacitation or hypoglycaemia is acceptable for the intended operations, including single-pilot IR flying.