AIRCRAFT INVESTIGATION
weight and performance calculations for the De Havilland D.H.34
De Havilland D.H.34
role : medium weight passenger aircraft
importance : ***
first flight : 26 March 1922 operational : April 1922
country : United-Kingdom
design : Geoffrey de Havilland
production : 12 aircraft
general information :
Further development of the D.H.18. Wooden plywood-clad fuselage, wooden wings. Heavily used on the cross channel air service. The 2 nd aircraft flew 160.000 km without overhaul (865 flying hours at 185 km/hr cruise speed). Imperial airways retained the type in service until March 1926.
It had hinged access panels for the Napier Lion engine which opened to the horizontal giving the ground crew a neat platform for engine maintenance.
The engine had a inertia starter so no need to swing the propellor to start the engine.
users : Daimler Airway , Instone Air Line , Imperial Airways
registrations : G-EBBQ (crashed w/o 15 Aug 1923) , G-EBBR (w/o after crash 27 May 1924), G-EBBS (w/o after crash 14 Sep 1923) , G-EBBT, G-EBBU (w/o after crash 3 Nov 1922) G-EBBV, G-EBBW, G-EBBX (w/o after crash 24 December 1924), G-EBBY (DH34B w/o after crash 3 July 1925), G-EBCX (w/o after crash 23 Sep1924)
crew : 1 passengers : 8
engine : 1 Napier Lion W-12 liquid-cooled 12 -cylinder W-engine 450 [hp](335.6 KW)
dimensions :
wingspan : 15.65 [m], length : 11.89 [m], height : 3.66[m]
wing area : 55.0 [m^2]
weights :
max.take-off weight : 3266 [kg]
empty weight operational : 2075 [kg] useful load : 800 [kg]
performance :
maximum speed :206 [km/hr] at sea-level
cruise speed :185 [km/u] op 100 [m]
service ceiling : 3000 [m]
range : 510 [km]
description :
2-bay biplane with fixed landing gear and tail strut
two spar upper and lower wing
engines, landing gear attached to the fuselage, luggage compartment in the rear of the fuselage
airscrew :
fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.65 [ ]
estimated diameter airscrew 3.79 [m]
angle of attack prop : 15.53 [ ]
reduction : 0.66 [ ]
airscrew revs : 1384 [r.p.m.]
pitch at Max speed 2.48 [m]
blade-tip speed at Vmax and max revs. : 281 [m/s]
calculation : *1* (dimensions)
wing chord : 1.90 [m]
mean wing chord : 1.76 [m]
calculated wing chord (rounded leading edge tips): 1.80 [m]
wing aspect ratio : 8.91 []
Length : 39 ft = 11.89m span 51 ft : 15.54m chord 6 ft 3 in : 1.90m wing area : 54.81m2. According Wikipedia it could carry 10 passengers, but looking at above drawing it could only take 8 passengers. 10 passengers would have to be cramped inside.
estimated gap : 2.02 [m]
gap/chord : 1.15 [ ]
seize (span*length*height) : 681 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 6.4 [kg/hr]
fuel consumption(cruise speed) : 77.1 [kg/hr] (105.1 [litre/hr]) at 75 [%] power
distance flown for 1 kg fuel : 2.41 [km/kg] at 1500 [m] cruise height, sfc : 306.0 [kg/kwh]
estimated total fuel capacity : 328 [litre] (241 [kg])
calculation : *3* (weight)
weight engine(s) dry : 435.0 [kg] = 1.30 [kg/KW]
weight reduction gear : 20.1 [kg]
weight 31.8 litre oil tank : 2.71 [kg]
oil tank filled with 2.5 litre oil : 2.3 [kg]
oil in engine 18.7 litre oil : 16.8 [kg]
fuel in engine 2.3 litre fuel : 1.68 [kg]
weight 44.7 litre gravity patrol tank(s) : 6.7 [kg]
weight radiator : 53.7 [kg]
weight exhaust pipes & fuel lines 39.4 [kg]
weight self-starter : 8.2 [kg]
weight cowling 13.4 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 62.6 [kg]
total weight propulsion system : 680 [kg](20.8 [%])
***************************************************************
fuselage skeleton (wood gauge : 10.82 [cm]): 356 [kg]
cabin layout : pitch : 87 [cm] (1+1) seating in 4.0 rows
pathway is very narrow > check !
weight toilet : 5 [kg]
weight 8.0 windows : 7.20 [kg]
passenger cabin width : 1.17 [m] cabin length : 3.48 [m] cabin height : 1.80 [m]
weight cabin furbishing : 14.64 [kg]
weight cabin floor : 26.10 [kg]
bracing : 29.9 [kg]
fuselage covering ( 26.7 [m2] doped linen fabric) : 8.1 [kg]
weight instruments. : 2.5 [kg]
weight lighting : 2.0 [kg]
weight controls : 6.2 [kg]
weight seats : 45.0 [kg]
weight 284 [litre] main fuel tank empty : 22.7 [kg]
weight air conditioning : 12 [kg]
weight engine mounts & firewalls : 17 [kg]
total weight fuselage : 554 [kg](17.0 [%])
***************************************************************
weight wing covering (doped linen fabric) : 49 [kg]
total weight ribs (152 ribs) : 194 [kg]
load on front upper spar (clmax) per running metre : 1475.0 [N]
load on rear upper spar (vmax) per running metre : 600.5 [N]
total weight 8 spars : 207 [kg]
weight wings : 450 [kg]
weight wing/square meter : 8.18 [kg]
weight 8 interplane struts & cabane : 62.1 [kg]
weight cables (90 [m]) : 29.3 [kg] (= 326 [gram] per metre)
diameter cable : 7.3 [mm]
weight fin & rudder (2.8 [m2]) : 23.7 [kg]
weight stabilizer & elevator (6.2 [m2]): 51.0 [kg]
total weight wing surfaces & bracing : 616 [kg] (18.9 [%])
*******************************************************************
wheel pressure : 1633.0 [kg]
weight 2 wheels (1000 [mm] by 154 [mm]) : 60.9 [kg]
weight tailskid : 12.7 [kg]
weight undercarriage with axle 111.3 [kg]
total weight landing gear : 185.0 [kg] (5.7 [%]
*******************************************************************
********************************************************************
calculated empty weight : 2035 [kg](62.3 [%])
weight oil for 3.3 hours flying : 21.0 [kg]
weight cooling fluids : 72.5 [kg]
calculated operational weight empty : 2129 [kg] (65.2 [%])
published operational weight empty : 2075 [kg] (63.5 [%])
_____________
| | o | |
-------------
"
weight crew : 81 [kg]
weight fuel for 2.0 hours flying : 154 [kg]
********************************************************************
operational weight empty: 2364 [kg](72.4 [%])
weight 8 passengers : 616 [kg]
weight luggage & freight : 184 [kg]
operational weight loaded: 3164 [kg](72.4 [%])
fuel reserve : 86.5 [kg] enough for 1.12 [hours] flying
possible additional useful load : 16 [kg]
operational weight fully loaded : 3266 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 3266 [kg] (100.0 [%])
||
||
I||==|
||
||
calculation : * 4 * (engine power)
power loading (Take-off) : 9.73 [kg/kW]
power loading (operational without useful load) : 7.04 [kg/kW]
total power : 335.6 [kW] at 2100 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 3.1 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.8 [g]
design flight time : 2.20 [hours]
design cycles : 2548 sorties, design hours : 5608 [hours]
operational wing loading : 421 [N/m^2]
wing stress (3 g) during operation : 155 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.37 ["]
max. angle of attack (stalling angle) : 11.62 ["]
angle of attack at max. speed : 1.05 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° :0.12 [ ]
lift coefficient at max. angle of attack : 1.14 [ ]
lift coefficient at max. speed : 0.21 [ ]
induced drag coefficient at max. speed : 0.0029 [ ]
drag coefficient at max. speed : 0.0346 [ ]
drag coefficient (zero lift) : 0.0317 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded : 3189 [kg]): 103 [km/u]
landing speed at sea-level: 121 [km/hr]
min. drag speed (max endurance) : 140 [km/hr] at 1500 [m](power :50 [%])
min. power speed (max range) : 140 [km/hr] at 1500 [m] (power:50 [%])
max. rate of climb speed : 124.0 [km/hr] at sea-level
cruising speed : 185 [km/hr] op 1500 [m] (power:77 [%])
design speed prop : 196 [km/hr]
maximum speed : 206 [km/hr] op 100 [m] (power:106 [%])
climbing speed at sea-level : 302 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 124.7 [km/u]
emergency/TO power : 470 [hp] at 2200 [rpm]
static prop wash : 157 [km/u]
take-off distance at sea-level : 176 [m]
lift/drag ratio : 11.14 [ ]
climb to 1000m with max payload : 7.11 [min]
climb to 2000m with max payload : 17.45 [min]
climb to 3000m with max payload : 32.12 [min]
published ceiling (3000 [m]
practical ceiling (operational weight) : 6273 [m] with flying weight :2364 [kg] line 3385
practical ceiling fully loaded (mtow- 30 min.fuel) : 4158 [m] with flying weight :3227 [kg]
max. dive speed : 463.1 [km/hr] at 3158 [m] height
turning speed at CLmax : 133.8 [km/u] at 50 [m] height
turn radius at 50m: 69 [m]
time needed for 360* turn 11.6 [seconds] at 50m
load factor at max. angle turn 2.28 ["g"]
calculation *10* (action radius & endurance)
published range : 510 [km] with 1 crew and 844.5 [kg] useful load and 88.1 [%] fuel
range : 617 [km] with 1 crew and 800.0 [kg] useful load and 106.6 [%] fuel
range : 867 [km] with 8.0 passengers with each 10 [kg] luggage and 149.8 [%] fuel
Available Seat Kilometers (ASK) : 6939 [paskm]
max range theoretically with additional fuel tanks for total 1441.3 [litre] fuel : 2542.0 [km]
useful load with range 500km : 849 [kg]
useful load with range 500km : 8 passengers
production (useful load): 157.34 [tonkm/hour]
production (passengers): 1483.20 [paskm/hour]
oil and fuel consumption per tonkm : 0.53 [kg]
oil and fuel consumption per paskm : 0.06 [kg]
fuel cost per paskm : 0.06 [eur]
crew cost per paskm : 0.10 [eur]
__
I=°_°°°°/
°
time between engine failure : 220 [hr]
writing off per paskm : 0.18 [eur]
insurance per paskm : 0.0884 [eur]
rigging cost per paskm : 0.0082 [eur]
maintenance cost per paskm : 0.2947 [eur]
direct operating cost per paskm : 0.72 [eur]
serious accidents :
Remains of G-EBBS
The burned out wreckage of G-EBBX
Literature :
Piston-engined airliners page 13
Wikipedia
DISCLAIMER Above calculations are based on published data, they must be
regarded as indication not as facts.
Calculated performance and weight may not correspond with actual weights
and performances and are assumptions for which no responsibility can be taken.
Calculations are as accurate as possible, they can be fine-tuned when more data
is available, you are welcome to give suggestions and additional information
so we can improve our program. For copyright on drawings/photographs/
content please mail to below mail address
(c) B van der Zalm 10 May 2021 contact : info.aircraftinvestigation@gmail.com python 3.7.4