DC-3 UNDERCARRIAGE DOORS
(Garrett AiResearch Maximizer Kit)

 

 


Readers familiar with the Douglas DC-3 may be thinking that DC-3s did not have undercarriage doors and indeed most did not. With a non-retractable tailwheel and the mainwheels protruding below the engine nacelles it was intended that this would minimise airframe damage in the event of a "belly landing". Notwithstanding damage to the propellors, it did indeed serve this function on many occasions. One undesirable consequence of this design was drag. As DC-3s became popular as corporate transports in the post-war years, speed became an important consideration. To address this need, Garrett AiResearch Corporation developed a DC-3 retrospective modification kit which they marketed under the name "Maximizer". The kit included a number of features such as:

Main undercarriage doors
Aerodynamic refinements to the tailwheel area
Redesigned engine cowls with internal cooling baffles. The diameter of the open face of the cowl was reduced significantly.
Oil cooler fairings
Redesigned exhaust system

The manufacturer's marketing promised a guaranteed 20 m.p.h. increase in cruising speed.

The undercarriage doors in the QAM collection came from DC-3 PK-RDB (c/n 16147/32895)

 


History of Douglas DC-3 PK-RDB (msn 16147/32895)

 

14MAR45
  Delivered to the USAAF as a C-47B-30-DK with the serial 44-76563. (Source: 1)
04APR45
  Delivered to No. 41 Squadron Royal New Zealand Air Force with the serial NZ3537. (Source: 1)
28APR47
  Registered ZK-AOZ to the NZ Government. (Source: 1)
11MAR48
  Registered ZK-AOZ to New Zealand National Airways and named "Pakara". (Source: 1)
30JUN62
  Withdrawn from service by NAC (Total Time: 28896 hrs) (Source: 3)
MAY63
  The aircraft was overhauled by NAC at Christchurch and fitted with a Garrett AiResearch Maximizer kit. (Source: 3)
24MAY63
  Test flown at Christchurch after overhaul and modifications. (Source: 3)
MAY63
  The aircraft made further test flights from Christchurch after which it positioned to Auckland. (Source: 6)
31MAY63
  Departed from Auckland for Norfolk Island, Nadi and Faleolo under the command of Captain M.D. Buchanan of TEAL. The aircraft was leased to Polynesian Airlines to replace the Percival Princes ZK-BYN and ZK-BYO on services Faleolo-Pago Pago and Faleolo-Aitutaki-Rarotongo. The aircraft regularly flew the 800 mile route between Samoa and Rarotonga. It was for this route that the aircraft had been fitted with the Maximixer kit for the purpose of increasing its range. On this sector the aircraft was limited to just 12 passengers because of the fuel load required. (Source: 3)
18JUN63
  Registered to Polynesian Airlines as 5W-FAA and named "Upolu". (Source: 1)
27DEC67
  Arrived at Auckland on completion of Polynesian lease. (Source: 2)
68
  Sold to Australian Aircraft Sales, Sydney. (Source: 2)
28SEP68
  Departed Auckland for Norfolk Island. (Source: 2) Flown by Bill Pike and John Lindner. (Source: 7)
30SEP68
  Arrived Brisbane from Norfolk Island. At this time the aircraft was marked PK-RDB. (Source: 4)
30SEP68
  Registered PK-RDB to Seulawah Air Service, Indonesia. (Source: 1)
02OCT68
  Arrived at Darwin where the aircraft was parked awaiting payment from the new owner. Bureaucracy became involved and the aircraft was impounded by HM Customs. The aircraft was subsequently abandoned at Darwin. (Source: 7)
25DEC74
  Darwin was devastated by Cyclone Tracy and PK-RDB was blown over a hangar, landing inverted and effectively destroyed. (Source: 5)
    The remains of PK-RDB were acquired by the Aviation Historical Society of the Northern Territory to provide parts for the rebuild of RAAF Dakota A65-104 which was also damaged in the cyclone.
DEC10
  The AHSNT, having previously decided to scrap the wing centre section of PK-RDB, agreed to donate the undercarriage doors to QAM. Remarkably, all four doors escaped damage in the cyclone and subsequent clearance of debris.
JUL11
  The doors arrived at QAM Caloundra.

 


 

SOURCES
1
J.M.G. Gradidge "The Douglas DC-3 and its predecessors", Air-Britain Historians, first edition 1984.
2
Geoff Goodall
3
Richard Waugh et al "The Illustrated History of NZNAC 1947-1978", Craig Printing, second edition 2008
4
David Thollar
5
Photograph contained in the papers of AIRCDRE D.W. Hitchins who was OC RAAF Darwin at the time.
6
AHSNZ Journal July 1963.
7
F.W. (Bill) Pike, correspondence in October 2012.

 

Compiled by Ron Cuskelly

 

To view this page as it was designed please click HERE

 

 


ISSUE
DATE
REMARKS
3
29JUN17
Added an image showing the extent of the cyclone damage to PK-RDB.
2
01OCT12
Added details of the ferry flight to Darwin from Source 7.
1
16SEP12
Original issue.