# AD 2000-24-51: Blade Spar - Type: Emergency airworthiness directive - Status: Historical - Products: MD Helicopter 369A, 369D, 369E, 369FF, 369H, 369HE, 369HM, 369HS and 500N - Issued: November 21, 2000 - Issued as: Emergency AD - Superseded by: [AD 2000-25-52](https://openairdocs.org/ad/2000-25-52) - Product type: Aircraft, Rotorcraft - Docket: 2000-SW-62-AD - Registered aircraft: 647 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CB88B7D48E56C6CA86256CCC0070C966.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/2000-24-51 ## The airworthiness directive AIRWORTHINESS DIRECTIVES EMERGENCY RULES: 2000-24-51 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 2000-SW-62-AD AMENDMENT: AD NUMBER: 2000-24-51 SUBJECT HEADING: MD Helicopters, Inc. Model 369A, H, HE, HM, HS, D, E, FF and 500N Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: Marc Belhumeur, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone (817) 222-5177, fax (817) 222-5783. SUPPLEMENTARY INFORMATION: DATE: November 21, 2000 2000-24-51 Send to all U.S. owners and operators of MD Helicopters, Inc. Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters. This Emergency Airworthiness Directive (AD) is prompted by a main rotor blade (blade) failure due to fatigue cracking that originated at corrosion pits on the spar bonded surfaces, resulting in an accident that destroyed a Hughes Model 369D helicopter. This condition, if not detected, could result in failure of a blade and subsequent loss of control of the helicopter. The FAA has reviewed Helicopter Technology Company, LLC, Mandatory Service Bulletin No. 2100-2R2, dated November 14, 2000 (SB), which describes procedures for performing a one- time inspection of each blade for skin-to-spar bonding voids before further flight. We have identified an unsafe condition that is likely to exist or develop on other MD Helicopters, Inc. Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters of these same type designs. Therefore, this AD requires, before further flight, performing a tap inspection on both the upper and lower surfaces of each blade. If any voids are detected that exceed specified inspection requirements, this AD requires replacing the unairworthy blade with an airworthy blade before further flight. The actions are required to be accomplished in accordance with the SB described previously. This rule is issued under 49 U.S.C. Section 44701 pursuant to the authority delegated to me by the Administrator, and is effective immediately upon receipt of this emergency AD. REGULATORY TEXT: 2000-24-51 MD HELICOPTERS, INC., Docket No. 2000-SW-62-AD. Applicability: Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters, with main rotor blade (blade), part number (P/N) 500P2100-BSC (serial number (S/N) K101 through K562; P/N 500P2100-101 (S/N A001 through A999), blade P/N 500P2100-301 (S/N B001 through B529), or blade, P/N 500P2300-501 (S/N T101 through T107), manufactured by Helicopter Technology Company, LLC, installed, certificated in any category. NOTE 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required before further flight, unless accomplished previously. To detect a void in the bonding that could result in a crack due to corrosion pits on the blade spar bonded surfaces, failure of a blade, and subsequent loss of control of the helicopter, accomplish the following: (a) Perform a tap inspection on both the upper and lower surfaces of each blade in accordance with the "INSPECTION" paragraph of Helicopter Technology Company, LLC, Mandatory Service Bulletin Notice No. 2100-2R2, dated November 14, 2000 (SB). If any voids on a blade are detected that exceed specified inspection requirements of the SB, replace the unairworthy blade with an airworthy blade before further flight. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Certification Office, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office. NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office. (c) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished. (d) Copies of the applicable service information may be obtained from Helicopter Technology Company, LLC, 12923 South Spring St., Los Angeles, CA 90061, telephone (310) 523-2750, fax (310) 523-2745. (e) Emergency AD 2000-24-51, issued November 21, 2000, becomes effective upon receipt. FOOTER: Issued in Fort Worth, Texas, on November 21, 2000. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H3WE](https://openairdocs.org/tcds/H3WE): MD Helicopters LLC; names 9 of 12 models: 369D, 369E, 369FF, 369HS, 369HM, 500N, 369HE, 369H… ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 647 (647 by airframe model, 0 by engine model) - Makers: Hughes Helicopters 241, MD Helicopters 155, Hughes 116, Mcdonnell Douglas Helicopter 110, Mcdonnell Douglas Heli 17, Summa 5, Hughes/Batto John 1, Hughes/Helicopter Assocs 1, Mcdonnell Douglas Mdhs 1 Models with the most aircraft: - [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d): 207 aircraft (airframe model) - [MD Helicopters 369FF](https://openairdocs.org/model/md-helicopters-369ff): 94 aircraft (airframe model) - [Mcdonnell Douglas Helicopter 369E](https://openairdocs.org/model/mcdonnell-douglas-helicopter-369e): 83 aircraft (airframe model) - [Hughes 369HS](https://openairdocs.org/model/hughes-369hs): 69 aircraft (airframe model) - [MD Helicopters 369E](https://openairdocs.org/model/md-helicopters-369e): 42 aircraft (airframe model) - [Hughes 369A](https://openairdocs.org/model/hughes-369a): 32 aircraft (airframe model) - [Hughes Helicopters 369E](https://openairdocs.org/model/hughes-helicopters-369e): 29 aircraft (airframe model) - [Mcdonnell Douglas Helicopter 500N](https://openairdocs.org/model/mcdonnell-douglas-helicopter-500n): 27 aircraft (airframe model) - [Mcdonnell Douglas Heli 369FF](https://openairdocs.org/model/mcdonnell-douglas-heli-369ff): 17 aircraft (airframe model) - [MD Helicopters 500N](https://openairdocs.org/model/md-helicopters-500n): 13 aircraft (airframe model) - [Hughes 369A (OH-6A)](https://openairdocs.org/model/hughes-369a-oh-6a): 11 aircraft (airframe model) - [Hughes Helicopters 369FF](https://openairdocs.org/model/hughes-helicopters-369ff): 5 aircraft (airframe model) - [Summa 369D](https://openairdocs.org/model/summa-369d): 4 aircraft (airframe model) - [MD Helicopters 369HS](https://openairdocs.org/model/md-helicopters-369hs): 3 aircraft (airframe model) - [Hughes 369HE](https://openairdocs.org/model/hughes-369he): 3 aircraft (airframe model) - [MD Helicopters 369HM](https://openairdocs.org/model/md-helicopters-369hm): 2 aircraft (airframe model) - [Summa 369HS](https://openairdocs.org/model/summa-369hs): 1 aircraft (airframe model) - [MD Helicopters 369A](https://openairdocs.org/model/md-helicopters-369a): 1 aircraft (airframe model) - [Mcdonnell Douglas Mdhs 369E](https://openairdocs.org/model/mcdonnell-douglas-mdhs-369e): 1 aircraft (airframe model) - [Hughes/Helicopter Assocs 369A](https://openairdocs.org/model/hughes-helicopter-assocs-369a): 1 aircraft (airframe model) All 24 models: https://openairdocs.org/ad/2000-24-51/models.md Every aircraft: https://openairdocs.org/ad/2000-24-51/aircraft.md ## Related documents - [AD 2000-25-52](https://openairdocs.org/ad/2000-25-52): Main rotor blade · MD Helicopters 369A, 369D, 369E and 6 more. Effective Feb 6, 2001. Supersedes this AD Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.